Production, characterisation, and cytocompatibility of porous titanium-based particulate scaffolds.

PubMed

Luthringer, B J C; Ali, F; Akaichi, H; Feyerabend, F; Ebel, T; Willumeit, R

2013-10-01

Despite its non-matching mechanical properties titanium remains the preferred metal implant material in orthopaedics. As a consequence in some cases stress shielding effect occurs, leading to implant loosening, osteopenia, and finally revision surgery. Porous metal scaffolds to allow easier specialised cells ingrowth with mechanical properties closer to the ones of bone can overcome this problem. This should improve healing processes, implant integration, and dynamic strength of implants retaining. Three Ti-6Al-4V materials were metal injection moulded and tailored porosities were effectively achieved. After microstructural and mechanical characterisation, two different primary cells of mesenchymal origin (human umbilical cord perivascular cells and human bone derived cells which revealed to be two pertinent models) as well as one cell line originated from primary osteogenic sarcoma, Saos-2, were bestowed to investigate cell-material interaction on genomic and proteome levels. Biological examinations disclosed that no material has negative impact on early adhesion, proliferation or cell viability. An efficient cell ingrowth into material with an average porosity of 25-50 μm was proved.

Breast implant capsule-associated squamous cell carcinoma: a report of 2 cases.

PubMed

Olsen, Daniel L; Keeney, Gary L; Chen, Beiyun; Visscher, Daniel W; Carter, Jodi M

2017-09-01

The use of prosthetic implants for breast augmentation has become commonplace. Although implants do not increase the risk of conventional mammary carcinoma, they are rarely associated with anaplastic large cell lymphoma. We report 2 cases of breast implant capsule-associated squamous cell carcinoma with poor clinical outcomes. Both patients (56-year-old woman and 81-year-old woman) had long-standing implants (>25 years) and presented with acute unilateral breast enlargement. In both cases, squamous cell carcinoma arose in (focally dysplastic) squamous epithelium-lined breast implant capsules and widely invaded surrounding breast parenchyma or chest wall. Neither patient had evidence of a primary mammary carcinoma or squamous cell carcinoma at any other anatomic site. Within 1 year, one patient developed extensive, treatment-refractory, locoregional soft tissue metastasis, and the second patient developed hepatic and soft tissue metastases and died of disease. There are 2 prior reported cases of implant-associated squamous cell carcinoma in the plastic surgery literature; one provides no pathologic staging or outcome information, and the second case was a capsule-confined squamous cell carcinoma. Together, all 4 cases share notable commonalities: the patients had long-standing breast implants and presented with acute unilateral breast pain and enlargement secondary to tumors arising on the posterior aspect of squamous epithelialized implant capsules. Because of both its rarity and its unusual clinical presentation, implant capsule-associated squamous cell carcinoma may be underrecognized. The aggressive behavior of the tumors in this series underscores the importance of excluding malignancy in patients with long-standing breast implants who present with acute unilateral breast pain and enlargement. Copyright © 2017 Elsevier Inc. All rights reserved.

Optimization of Glioblastoma Mouse Orthotopic Xenograft Models for Translational Research.

PubMed

Irtenkauf, Susan M; Sobiechowski, Susan; Hasselbach, Laura A; Nelson, Kevin K; Transou, Andrea D; Carlton, Enoch T; Mikkelsen, Tom; deCarvalho, Ana C

2017-08-01

Glioblastoma is an aggressive primary brain tumor predominantly localized to the cerebral cortex. We developed a panel of patient-derived mouse orthotopic xenografts (PDOX) for preclinical drug studies by implanting cancer stem cells (CSC) cultured from fresh surgical specimens intracranially into 8-wk-old female athymic nude mice. Here we optimize the glioblastoma PDOX model by assessing the effect of implantation location on tumor growth, survival, and histologic characteristics. To trace the distribution of intracranial injections, toluidine blue dye was injected at 4 locations with defined mediolateral, anterioposterior, and dorsoventral coordinates within the cerebral cortex. Glioblastoma CSC from 4 patients and a glioblastoma nonstem-cell line were then implanted by using the same coordinates for evaluation of tumor location, growth rate, and morphologic and histologic features. Dye injections into one of the defined locations resulted in dye dissemination throughout the ventricles, whereas tumor cell implantation at the same location resulted in a much higher percentage of small multifocal ventricular tumors than did the other 3 locations tested. Ventricular tumors were associated with a lower tumor growth rate, as measured by in vivo bioluminescence imaging, and decreased survival in 4 of 5 cell lines. In addition, tissue oxygenation, vasculature, and the expression of astrocytic markers were altered in ventricular tumors compared with nonventricular tumors. Based on this information, we identified an optimal implantation location that avoided the ventricles and favored cortical tumor growth. To assess the effects of stress from oral drug administration, mice that underwent daily gavage were compared with stress-positive and -negative control groups. Oral gavage procedures did not significantly affect the survival of the implanted mice or physiologic measurements of stress. Our findings document the importance of optimization of the implantation site for preclinical mouse models of glioblastoma.

Optimization of Glioblastoma Mouse Orthotopic Xenograft Models for Translational Research

PubMed Central

Irtenkauf, Susan M; Sobiechowski, Susan; Hasselbach, Laura A; Nelson, Kevin K; Transou, Andrea D; Carlton, Enoch T; Mikkelsen, Tom; deCarvalho, Ana C

2017-01-01

Glioblastoma is an aggressive primary brain tumor predominantly localized to the cerebral cortex. We developed a panel of patient-derived mouse orthotopic xenografts (PDOX) for preclinical drug studies by implanting cancer stem cells (CSC) cultured from fresh surgical specimens intracranially into 8-wk-old female athymic nude mice. Here we optimize the glioblastoma PDOX model by assessing the effect of implantation location on tumor growth, survival, and histologic characteristics. To trace the distribution of intracranial injections, toluidine blue dye was injected at 4 locations with defined mediolateral, anterioposterior, and dorsoventral coordinates within the cerebral cortex. Glioblastoma CSC from 4 patients and a glioblastoma nonstem-cell line were then implanted by using the same coordinates for evaluation of tumor location, growth rate, and morphologic and histologic features. Dye injections into one of the defined locations resulted in dye dissemination throughout the ventricles, whereas tumor cell implantation at the same location resulted in a much higher percentage of small multifocal ventricular tumors than did the other 3 locations tested. Ventricular tumors were associated with a lower tumor growth rate, as measured by in vivo bioluminescence imaging, and decreased survival in 4 of 5 cell lines. In addition, tissue oxygenation, vasculature, and the expression of astrocytic markers were altered in ventricular tumors compared with nonventricular tumors. Based on this information, we identified an optimal implantation location that avoided the ventricles and favored cortical tumor growth. To assess the effects of stress from oral drug administration, mice that underwent daily gavage were compared with stress-positive and ‑negative control groups. Oral gavage procedures did not significantly affect the survival of the implanted mice or physiologic measurements of stress. Our findings document the importance of optimization of the implantation site for preclinical mouse models of glioblastoma. PMID:28830577

The structurally effect of surface coated rhamnogalacturonan I on response of the osteoblast-like cell line SaOS-2.

PubMed

Svava, Rikke; Gurzawska, Katarzyna; Yihau, Yu; Haugshøj, Kenneth Brian; Dirscherl, Kai; Levery, Steven B; Jørgensen, Niklas Rye; Gotfredsen, Klaus; Damager, Iben; Ulvskov, Peter; Jørgensen, Bodil

2014-06-01

Osseointegration is important when implants are inserted into the bone and can be improved by biochemical surface coating of the implant. In this paper enzymatically modified rhamnogalacturonan I (RG-I) from apple and lupin was used for biochemical coating of aminated surfaces and the importance of the quality of RG-I, the nature of the binding, the fine structure of RG-I, and its effect on SaOS-2 cell line cultured on coated surfaces was investigated. SaOS-2 cells are osteoblast-like cells and a well-established in vitro model of bone-matrix forming osteoblasts. Purification by gel filtration could remove small fragments of galacturonic acid (GalA) and binding studies showed that the purity of the RG-I molecules was important for the quality of the coating. The structure of RG-I and osteoblast-like cells' viability were positively correlated so that high content of 1,4-linked galactose (Gal) and a low content of arabinose in the RG-I molecules favored cell viability. These results indicate that coating of implants with RG-I affect osseointegration positively. Copyright © 2013 Wiley Periodicals, Inc.

The Next Generation of Orthotopic Thyroid Cancer Models: Immunocompetent Orthotopic Mouse Models of BRAFV600E-Positive Papillary and Anaplastic Thyroid Carcinoma

PubMed Central

Vanden Borre, Pierre; McFadden, David G.; Gunda, Viswanath; Sadow, Peter M.; Varmeh, Shohreh; Bernasconi, Maria; Jacks, Tyler

2014-01-01

Background: While the development of new treatments for aggressive thyroid cancer has advanced in the last 10 years, progress has trailed headways made with other malignancies. A lack of reliable authenticated human cell lines and reproducible animal models is one major roadblock to preclinical testing of novel therapeutics. Existing xenograft and orthotopic mouse models of aggressive thyroid cancer rely on the implantation of highly passaged human thyroid carcinoma lines in immunodeficient mice. Genetically engineered models of papillary and undifferentiated (anaplastic) thyroid carcinoma (PTC and ATC) are immunocompetent; however, slow and stochastic tumor development hinders high-throughput testing. Novel models of PTC and ATC in which tumors arise rapidly and synchronously in immunocompetent mice would facilitate the investigation of novel therapeutics and approaches. Methods: We characterized and utilized mouse cell lines derived from PTC and ATC tumors arising in genetically engineered mice with thyroid-specific expression of endogenous BrafV600E/WT and deletion of either Trp53 (p53) or Pten. These murine thyroid cancer cells were transduced with luciferase- and GFP-expressing lentivirus and implanted into the thyroid glands of immunocompetent syngeneic B6129SF1/J mice in which the growth characteristics were assessed. Results: Large locally aggressive thyroid tumors form within one week of implantation. Tumors recapitulate their histologic subtype, including well-differentiated PTC and ATC, and exhibit CD3+, CD8+, B220+, and CD163+ immune cell infiltration. Tumor progression can be followed in vivo using luciferase and ex vivo using GFP. Metastatic spread is not detected at early time points. Conclusions: We describe the development of the next generation of murine orthotopic thyroid cancer models. The implantation of genetically defined murine BRAF-mutated PTC and ATC cell lines into syngeneic mice results in rapid and synchronous tumor formation. This model allows for preclinical investigation of novel therapeutics and/or therapeutic combinations in the context of a functional immune system. PMID:24295207

SLM Produced Porous Titanium Implant Improvements for Enhanced Vascularization and Osteoblast Seeding

PubMed Central

Matena, Julia; Petersen, Svea; Gieseke, Matthias; Kampmann, Andreas; Teske, Michael; Beyerbach, Martin; Murua Escobar, Hugo; Haferkamp, Heinz; Gellrich, Nils-Claudius; Nolte, Ingo

2015-01-01

To improve well-known titanium implants, pores can be used for increasing bone formation and close bone-implant interface. Selective Laser Melting (SLM) enables the production of any geometry and was used for implant production with 250-µm pore size. The used pore size supports vessel ingrowth, as bone formation is strongly dependent on fast vascularization. Additionally, proangiogenic factors promote implant vascularization. To functionalize the titanium with proangiogenic factors, polycaprolactone (PCL) coating can be used. The following proangiogenic factors were examined: vascular endothelial growth factor (VEGF), high mobility group box 1 (HMGB1) and chemokine (C-X-C motif) ligand 12 (CXCL12). As different surfaces lead to different cell reactions, titanium and PCL coating were compared. The growing into the porous titanium structure of primary osteoblasts was examined by cross sections. Primary osteoblasts seeded on the different surfaces were compared using Live Cell Imaging (LCI). Cross sections showed cells had proliferated, but not migrated after seven days. Although the cell count was lower on titanium PCL implants in LCI, the cell count and cell spreading area development showed promising results for titanium PCL implants. HMGB1 showed the highest migration capacity for stimulating the endothelial cell line. Future perspective would be the incorporation of HMGB1 into PCL polymer for the realization of a slow factor release. PMID:25849656

A wireless transmission system powered by an enzyme biofuel cell implanted in an orange.

PubMed

MacVittie, Kevin; Conlon, Tyler; Katz, Evgeny

2015-12-01

A biofuel cell composed of catalytic electrodes made of "buckypaper" modified with PQQ-dependent glucose dehydrogenase and FAD-dependent fructose dehydrogenase on the anode and with laccase on the cathode was used to activate a wireless information transmission system. The cathode/anode pair was implanted in orange pulp extracting power from its content (glucose and fructose in the juice). The open circuit voltage, Voc, short circuit current density, jsc, and maximum power produced by the biofuel cell, Pmax, were found as ca. 0.6 V, ca. 0.33 mA·cm(-2) and 670 μW, respectively. The voltage produced by the biofuel cell was amplified with an energy harvesting circuit and applied to a wireless transmitter. The present study continues the research line where different implantable biofuel cells are used for the activation of electronic devices. The study emphasizes the biosensor and environmental monitoring applications of implantable biofuel cells harvesting power from natural sources, rather than their biomedical use. Copyright © 2014 Elsevier B.V. All rights reserved.

Genetic engineering of cell lines using lentiviral vectors to achieve antibody secretion following encapsulated implantation.

PubMed

Lathuilière, Aurélien; Bohrmann, Bernd; Kopetzki, Erhard; Schweitzer, Christoph; Jacobsen, Helmut; Moniatte, Marc; Aebischer, Patrick; Schneider, Bernard L

2014-01-01

The controlled delivery of antibodies by immunoisolated bioimplants containing genetically engineered cells is an attractive and safe approach for chronic treatments. To reach therapeutic antibody levels there is a need to generate renewable cell lines, which can long-term survive in macroencapsulation devices while maintaining high antibody specific productivity. Here we have developed a dual lentiviral vector strategy for the genetic engineering of cell lines compatible with macroencapsulation, using separate vectors encoding IgG light and heavy chains. We show that IgG expression level can be maximized as a function of vector dose and transgene ratio. This approach allows for the generation of stable populations of IgG-expressing C2C12 mouse myoblasts, and for the subsequent isolation of clones stably secreting high IgG levels. Moreover, we demonstrate that cell transduction using this lentiviral system leads to the production of a functional glycosylated antibody by myogenic cells. Subsequent implantation of antibody-secreting cells in a high-capacity macroencapsulation device enables continuous delivery of recombinant antibodies in the mouse subcutaneous tissue, leading to substantial levels of therapeutic IgG detectable in the plasma.

VIP induces the decidualization program and conditions the immunoregulation of the implantation process.

PubMed

Grasso, Esteban; Gori, Soledad; Paparini, Daniel; Soczewski, Elizabeth; Fernández, Laura; Gallino, Lucila; Salamone, Gabriela; Martinez, Gustavo; Irigoyen, Marcela; Ruhlmann, Claudio; Pérez Leirós, Claudia; Ramhorst, Rosanna

2018-01-15

The decidualization process involves phenotype and functional changes on endometrial cells and the modulation of mediators with immunoregulatory properties as the vasoactive intestinal peptide (VIP). We investigate VIP contribution to the decidualization program and to immunoregulation throughout the human embryo implantation process. The decidualization of Human endometrial stromal cell line (HESC) with Medroxyprogesterone-dibutyryl-cAMP increased VIP/VPAC-receptors system. In fact, VIP could induce decidualization increasing differentiation markers (IGFBP1, PRL, KLF13/KLF9 ratio, CXCL12, CXCL8 and CCL2) and allowing Blastocyst-like spheroids (BLS) invasion in an in vitro model of embryo implantation. Focus on the tolerogenic effects, decidualized cells induced a semi-mature profile on maternal dendritic cells; restrained CD4 + cells recruitment while increased regulatory T-cells recruitment. Interestingly, the human blastocyst conditioned media from developmentally impaired embryos diminished the invasion and T-regulatory cells recruitment in these settings. These evidences suggest that VIP contributes to the implantation process inducing decidualization, allowing BLS invasion and favoring a tolerogenic micro-environment. Copyright © 2017 Elsevier B.V. All rights reserved.

Trophinin expression in the mouse uterus coincides with implantation and is hormonally regulated but not induced by implanting blastocysts.

PubMed

Suzuki, N; Nadano, D; Paria, B C; Kupriyanov, S; Sugihara, K; Fukuda, M N

2000-11-01

Trophinin mediates apical cell adhesion between two human cell lines, trophoblastic teratocarcinoma and endometrial adenocarcinoma. In humans, trophinin is specifically expressed in cells involved in implantation and early placentation. The present study was undertaken to establish trophinin expression by the mouse uterus. In the pregnant mouse uterus, trophinin transcripts are expressed during the time which coincides with the timing of blastocyst implantation. Trophinin is also expressed in the nonpregnant mouse uterus at estrus stage. Uteri from ovariectomized mice did not express trophinin, whereas strong expression was induced by estrogen but not by progesterone. Trophinin transcripts and protein were found in the pseudopregnant mouse uterus. No differences were detected in trophinin expression by the uteri in the pregnant, pseudopregnant, and pseudopregnant received blastocysts. In delayed implantation model, trophinin proteins were found in both luminal and glandular epithelium, whereas dormant blastocysts were negative for trophinin. Upon activation with estrogen, however, no significant changes were detected either in the blastocyst or in the uterus. These results indicate that ovarian hormones regulate trophinin expression by the mouse uterus, and that an implanting blastocyst has no effect on trophinin expression in the surrounding endometrial luminal epithelial cells.

Development and Preclinical Application of an Immunocompetent Transplant Model of Basal Breast Cancer with Lung, Liver and Brain Metastases

PubMed Central

Hoenerhoff, Mark; Hixon, Julie A.; Durum, Scott K.; Qiu, Ting-hu; He, Siping; Burkett, Sandra; Liu, Zi-Yao; Swanson, Steven M.; Green, Jeffrey E.

2016-01-01

Triple negative breast cancer (TNBC) is an aggressive subtype of breast cancer that is associated with a poor prognosis and for which no targeted therapies currently exist. In order to improve preclinical testing for TNBC that relies primarily on using human xenografts in immunodeficient mice, we have developed a novel immunocompetent syngeneic murine tumor transplant model for basal-like triple-negative breast cancer. The C3(1)/SV40-T/t-antigen (C3(1)/Tag) mouse mammary tumor model in the FVB/N background shares important similarities with human basal-like TNBC. However, these tumors or derived cell lines are rejected when transplanted into wt FVB/N mice, likely due to the expression of SV40 T-antigen. We have developed a sub-line of mice (designated REAR mice) that carry only one copy of the C3(1)/Tag-antigen transgene resulting from a spontaneous transgene rearrangement in the original founder line. Unlike the original C3(1)/Tag mice, REAR mice do not develop mammary tumors or other phenotypes observed in the original C3(1)/Tag transgenic mice. REAR mice are more immunologically tolerant to SV40 T-antigen driven tumors and cell lines in an FVB/N background (including prostate tumors from TRAMP mice), but are otherwise immunologically intact. This transplant model system offers the ability to synchronously implant the C3(1)/Tag tumor-derived M6 cell line or individual C3(1)/Tag tumors from various stages of tumor development into the mammary fat pads or tail veins of REAR mice. C3(1)/Tag tumors or M6 cells implanted into the mammary fat pads spontaneously metastasize at a high frequency to the lung and liver. M6 cells injected by tail vein can form brain metastases. We demonstrate that irradiated M6 tumor cells or the same cells expressing GM-CSF can act as a vaccine to retard tumor growth of implanted tumor cells in the REAR model. Preclinical studies performed in animals with an intact immune system should more authentically replicate treatment responses in human patients. PMID:27171183

Minimum line width of ion beam-modified polystyrene by negative carbon ions for nerve-cell attachment and neurite extension

NASA Astrophysics Data System (ADS)

Sommani, P.; Tsuji, H.; Sato, H.; Kitamura, T.; Hattori, M.; Gotoh, Y.; Ishikawa, J.

2007-04-01

The minimum line width of the negative-ion-modified polystyrene (PS) for guidance and immobilizations of nerve-cell body and neurite extension have been investigated. Carbon negative ions were implanted into PS at fluence of 3 × 1015 ions/cm2 and energy of 5-20 keV through the various triangle apertures of the micro-pattern mask. After in vitro culture of the nerve-like cells of rat adrenal pheochromocytoma (PC12h), results showed that the minimum line widths for a single cell attachment and for neurite extension were 5-7 and 3-5 μm, respectively. While the minimum line width for attachment of cell group with long neurite was about 20 μm. The suitable widths for a large number of cells and for neurite extension were 20 and 5 μm, respectively. Therefore, the guidance for a clear separation of the attachment size of cell body and neurite extension could be achieved by the different modified line widths.

Study of Genetics and Embryology of Polyembryonic Mutant of Autotetraploid Rice Induced by N+ Beam Implantation

NASA Astrophysics Data System (ADS)

Dai, Ximei; Huang, Qunce; Li, Guoping; Hu, Xiuming; Qin, Guangyong; Yu, Zengliang

2006-11-01

In the present study autotetraploid rice IR36-4X was treated by an ion implantation technique with nitrogen ion beams. A polyembryonic mutant (named IR36-Shuang) was identified in the M2 generation. The mutant line and its offspring were systematically investigated in regard to their major agronomic properties and the rate of polyembryonic seedling in the M3-M6 generation. The abnormal phenomena in the embryo sac development and the cytological mechanism of the initiation of additional embryo in IR36-Shuang were observed by Laser Scanning Confocal Microscopy. The results were as follows. 1) The plant height, the panicle length and 1000 grain weight of IR36-Shuang were lower than that of its control by 35.41%, 5.08% and 15.72% respectively, Moreover, the setting percentage decreased 12.39% compared with that in normal IR36-4X plants. 2) The polyembryonic trait of IR36-Shuang was genetically stable and the frequency of the polyembryonic seedlings in the IR36-Shuang line was also relatively stable. 3) The rate of abnormal embryo sacs in IR36-Shuang was significantly higher than that in the control IR36-4X. 4) The additional embryo in IR36-Shuang might arise from the double set of embryo sacs in a single ovary, antipodal cells or endosperm cells. These results suggest that IR36-Shuang is a polyembryonic mutant and a new apomixis rice line induced by low energy ion implantation. The prospects for the application in production of the IR36-Shuang line are also discussed. The present study may provide a basis for future investigations of apomixis rice breeding via the ion implantation biotechnology.

Changes in biphasic electrode impedance with protein adsorption and cell growth

PubMed Central

Newbold, Carrie; Richardson, Rachael; Millard, Rodney; Huang, Christie; Milojevic, Dusan; Shepherd, Robert; Cowan, Robert

2012-01-01

This study was undertaken to assess the contribution of protein adsorption and cell growth to increases in electrode impedance that occur immediately following implantation of cochlear implant electrodes and other neural stimulation devices. An in vitro model of the electrode-tissue interface was used. Radiolabelled albumin in phosphate buffered saline was added to planar gold electrodes and electrode impedance measured using a charge-balanced biphasic current pulse. The polarisation impedance component increased with protein adsorption, while no change to access resistance was observed. The maximum level of protein adsorbed was measured at 0.5 μg/cm2, indicating a tightly packed monolayer of albumin molecules on the gold electrode and resin substrate. Three cell types were grown over the electrodes, macrophage cell line J774, dissociated fibroblasts and epithelial cell line MDCK, all of which created a significant increase in electrode impedance. As cell cover over electrodes increased, there was a corresponding increase in the initial rise in voltage, suggesting cell cover mainly contributes to the access resistance of the electrodes. Only a small increase in the polarisation component of impedance was seen with cell cover. PMID:20841637

The response of breast cancer cells to mesenchymal stem cells: a possible role of inflammation by breast implants.

PubMed

Orciani, Monia; Lazzarini, Raffaella; Scartozzi, Mario; Bolletta, Elisa; Mattioli-Belmonte, Monica; Scalise, Alessandro; Di Benedetto, Giovanni; Di Primio, Roberto

2013-12-01

Breast implants are widely used and at times might cause inflammation as a foreign body, followed by fibrous capsule formation around the implant. In cancer, the inflamed stroma is essential for preservation of the tumor. Mesenchymal stem cells can be recruited to sites of inflammation, and their role in cancer development is debated. The authors assessed the effects of inflammation caused by breast implants' effects on tumor. Mesenchymal stem cells were isolated from the fibrous capsules of women who underwent a second operation after 1 year (presenting inflammation) or after 20 years (not presenting inflammation) since initial surgery. After characterization, cells were co-cultured with MCF7, a breast cancer cell line. The expression of genes involved in oncogenesis, proliferation, and epithelial-to-mesenchymal transition was investigated, followed by Western blot analyses. After co-culture with mesenchymal stem cells from the inflamed capsule, MCF7 induced a dose- and time-dependent increase in proliferation. Polymerase chain reaction analyses revealed a dysregulation of genes involved in oncogenesis, proliferation, and epithelial-to-mesenchymal transition. The subsequent evaluation by Western blot did not confirm these results, showing only a modest decrease in the expression of E-cadherin after co-culture with mesenchymal stem cells (both derived from inflamed or control capsules). These data indicate that inflammation caused by breast implants partially affects proliferation of MCF7 but does not influence key mechanisms of tumor development.

Two-dimensional particle-in-cell plasma source ion implantation of a prolate spheroid target

NASA Astrophysics Data System (ADS)

Liu, Cheng-Sen; Han, Hong-Ying; Peng, Xiao-Qing; Chang, Ye; Wang, De-Zhen

2010-03-01

A two-dimensional particle-in-cell simulation is used to study the time-dependent evolution of the sheath surrounding a prolate spheroid target during a high voltage pulse in plasma source ion implantation. Our study shows that the potential contour lines pack more closely in the plasma sheath near the vertex of the major axis, i.e. where a thinner sheath is formed, and a non-uniform total ion dose distribution is incident along the surface of the prolate spheroid target due to the focusing of ions by the potential structure. Ion focusing takes place not only at the vertex of the major axis, where dense potential contour lines exist, but also at the vertex of the minor axis, where sparse contour lines exist. This results in two peaks of the received ion dose, locating at the vertices of the major and minor axes of the prolate spheroid target, and an ion dose valley, staying always between the vertices, rather than at the vertex of the minor axis.

Microglia Activate Migration of Glioma Cells through a Pyk2 Intracellular Pathway

PubMed Central

Rolón-Reyes, Kimberleve; Kucheryavykh, Yuriy V.; Cubano, Luis A.; Inyushin, Mikhail; Skatchkov, Serguei N.; Eaton, Misty J.; Harrison, Jeffrey K.; Kucheryavykh, Lilia Y.

2015-01-01

Glioblastoma is one of the most aggressive and fatal brain cancers due to the highly invasive nature of glioma cells. Microglia infiltrate most glioma tumors and, therefore, make up an important component of the glioma microenvironment. In the tumor environment, microglia release factors that lead to the degradation of the extracellular matrix and stimulate signaling pathways to promote glioma cell invasion. In the present study, we demonstrated that microglia can promote glioma migration through a mechanism independent of extracellular matrix degradation. Using western blot analysis, we found upregulation of proline rich tyrosine kinase 2 (Pyk2) protein phosphorylated at Tyr579/580 in glioma cells treated with microglia conditioned medium. This upregulation occurred in rodent C6 and GL261 as well as in human glioma cell lines with varying levels of invasiveness (U-87MG, A172, and HS683). siRNA knock-down of Pyk2 protein and pharmacological blockade by the Pyk2/focal-adhesion kinase (FAK) inhibitor PF-562,271 reversed the stimulatory effect of microglia on glioma migration in all cell lines. A lower concentration of PF-562,271 that selectively inhibits FAK, but not Pyk2, did not have any effect on glioma cell migration. Moreover, with the use of the CD11b-HSVTK microglia ablation mouse model we demonstrated that elimination of microglia in the implanted tumors (GL261 glioma cells were used for brain implantation) by the local in-tumor administration of Ganciclovir, significantly reduced the phosphorylation of Pyk2 at Tyr579/580 in implanted tumor cells. Taken together, these data indicate that microglial cells activate glioma cell migration/dispersal through the pro-migratory Pyk2 signaling pathway in glioma cells. PMID:26098895

Costimulatory molecule expression following exposure to orthopaedic implants wear debris.

PubMed

Bainbridge, J A; Revell, P A; Al-Saffar, N

2001-03-05

Patients with long-term orthopedic implants may develop inflammatory reactions due to the accumulation of biomaterial particles both around the implant and in distant organs. The exact impact of these particles on the normal immune cell function still remain relatively unclear. Activation of T-cells following exposure to biomaterial particles is driven by macrophages and requires synergistic signals primed by both antigen presentation and costimulation. The pattern of costimulatory molecule expression (CD80,CD86) was primarily examined using immunohistochemistry on tissue specimens of bone/implant interface membranes taken from sites of bone erosion. Additionally, costimulatory molecule expression was also assessed in the monocytic leukemia cell line U937 following exposure to clinically relevant titanium aluminum vanadium (TiAlV) and stainless steel particles (FeCrNi) cultured in vitro. This study demonstrates the induction and prominent expression of CD86 on almost all macrophage subsets at the bone/implant interface, including fused forms and large multinucleated giant cells (MNGC). In vitro analysis also indicated phagocytosis of metal particles by differentiated U937 caused significant induction of both CD80 and CD86 (p < 0.01), although the expression of CD86 dominated following prolonged exposure. The data presented highlights that CD86 is the predominant costimulatory molecule ligating to the complementary CD28 molecule at the inflammatory lesion of the interface. We propose that the intracellular presence of indigestible implant material, in addition to elevated costimulatory molecule expression, may promote T-cell inflammatory reactions at sites close to and distant from the orthopedic implant.

Biodegradation and cytotoxicity of ciprofloxacin-loaded hydroxyapatite-polycaprolactone nanocomposite film for sustainable bone implants.

PubMed

Nithya, Rajendran; Meenakshi Sundaram, Nachiappan

2015-01-01

In recent years there has been a steep increase in the number of orthopedic patients for many reasons. One major reason is osteomyelitis, caused by pyrogenic bacteria, with progressive infection of the bone or bone marrow and surrounding tissues. So antibiotics must be introduced during bone implantation to avoid prolonged infection. The objective of the study reported here was to prepare a composite film of nanocrystalline hydroxyapatite (HAp) and polycaprolactone (PCL) polymer loaded with ciprofloxacin, a frequently used antibiotic agent for bone infections. Nanocrystalline HAp was synthesized by precipitation method using the precursor obtained from eggshell. The nanocomposite film (HAp-PCL-ciprofloxacin) was prepared by solvent evaporation. Drug-release and biodegradation studies were undertaken by immersing the composite film in phosphate-buffered saline solution, while a cytotoxicity test was performed using the fibroblast cell line NIH-3T3 and osteoblast cell line MG-63. The pure PCL film had quite a low dissolution rate after an initial sharp weight loss, whereas the ciprofloxacin-loaded HAp-PCL nanocomposite film had a large weight loss due to its fast drug release. The composite film had higher water absorption than the pure PCL, and increasing the concentration of the HAp increased the water absorption. The in vitro cell-line study showed a good biocompatibility and bioactivity of the developed nanocomposite film. The prepared film will act as a sustainable bone implant in addition to controlled drug delivery.

Cell behavior related to implant surfaces with different microstructure and chemical composition: an in vitro analysis.

PubMed

Conserva, Enrico; Lanuti, Anna; Menini, Maria

2010-01-01

This paper reports on an in vitro comparison of osteoblast and mesenchymal stem cell (MSC) adhesion, proliferation, and differentiation related to two different surface treatments applied to the same implant design to determine whether the interaction between cells and implants is influenced by surface structure and chemical composition of the implants. Thirty-nine implants with a sandblasted (SB) surface and 39 implants with a grit-blasted and high-temperature acid-etched (GBAE) surface were used. The implant macrostructures and microstructures were analyzed by high- and low-voltage scanning electron microscopy (SEM) and by stereo-SEM. The surface chemical composition was investigated by energy dispersive analysis and x-ray photoemission spectroscopy. SaOS-2 osteoblasts and human MSCs were used for the evaluation of cell proliferation and alkaline phosphatase enzymatic activity in contact with the two surfaces. The GBAE surface showed fewer contaminants and a very high percentage of titanium (19.7%) compared to the SB surface (14.2%). The two surfaces showed similar mean roughness (Ra), but the depth (Rz) and density (RSm) of the porosity were significantly increased in the GBAE surface. The GBAE surface presented more osteoblast and MSC proliferation than the SB surface. No statistically significant differences in alkaline phosphatase activity were found between surfaces for either cellular line. The GBAE surface showed less surface contaminants and a higher percentage of titanium (19.7%) than the SB surface. The macro/micropore structured design and chemical composition of the GBAE surface allowed greater cell adhesion and proliferation and an earlier cell spreading but did not play an obvious role in in vitro cellular differentiation.

Establishment of nude mice with complete loss of lymphocytes and NK cells and application for in vivo bio-imaging.

PubMed

Kariya, Ryusho; Matsuda, Kouki; Gotoh, Kumiko; Vaeteewoottacharn, Kulthida; Hattori, Shinichiro; Okada, Seiji

2014-01-01

Nude mice are used in human xenograft research; however, only 25-35% of human tumors have been successfully transplanted into nude mice and their application is limited due to high natural killer (NK) cell activity. More severely immunodeficient mice with loss of NK activity are needed to overcome this limitation. Balb/c nude Rag-2(-/-)Jak3(-/-) (Nude-RJ) mice were established by crossing Rag-2(-/-)Jak3(-/-) mice and nude mice. The K562 cell line was implanted subcutaneously to compare tumorigenicity between Nude-RJ mice and Nude mice. The cholangiocarcinoma mCherry expressing cell line (KKU-M213) was implanted subcutaneously, and fluorescence intensity and tumor weight were measured. Nude R/J mice showed complete loss of lymphocytes and NK cells. Xeno-transplantation of K562 cells showed higher proliferation in Nude R/J mice than nude mice. Subcutaneously-transplanted mCherry-transduced KKU-M213 cells were successfully detected with a fluorescence imager. Nude-R/J mice are valuable tools for in vivo imaging studies in biomedical research. Copyright © 2014 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.

The effect of tetrathiomolybdate on cytokine expression, angiogenesis, and tumor growth in squamous cell carcinoma of the head and neck.

PubMed

Teknos, Theodoros N; Islam, Mozaffarul; Arenberg, Douglas A; Pan, Quintin; Carskadon, Shannon L; Abarbanell, Aaron M; Marcus, Benjamin; Paul, Supriti; Vandenberg, Curtis D; Carron, Michael; Nor, Jacques E; Merajver, Sofia D

2005-03-01

To assess the effect of tetrathiomolybdate on cytokine expression, angiogenesis, and tumor growth rate in human squamous cell carcinoma (SCC). Three human SCC cell lines were used in this study for both in vitro and in vivo investigations. Conditioned media from untreated and tetrathiomolybdate-treated cell lines were compared with regard to cytokine levels, endothelial cell chemotaxis, endothelial cell tubule formation, and migration and the ability to induce angiogenesis in a rat aortic ring array. In vivo UM-SCC-38 was seeded onto tissue-engineered scaffolds and surgically implanted into the flanks of immunodeficient mice. Tumor growth rates and the level of angiogenesis were compared after 2 weeks of therapy. A tertiary care facility. In this study, we demonstrate that tetrathiomolybdate significantly decreases the secretion of interleukin 6 and basic fibroblast growth factor by head and neck SCC (HNSCC) cell lines in vitro. Furthermore, we demonstrate that tetrathiomolybdate significantly decreases the secretion of interleukin 6 and basic fibroblast growth factor by HNSCC cell lines in vitro. Furthermore, tetrathiomolybdate treatment of HNSCC cell lines results in significantly decreased endothelial cell chemotaxis, tubule formation, and neovascularization in a rat aortic ring assay. This in vitro evidence of decreased angiogenesis by tetrathiomolybdate is confirmed in vivo by using a severe combined immunodeficiency disorder mouse model in which tetrathiomolybdate therapy is shown to prevent human blood vessel formation. Finally, human HNSCC implanted into immunodeficient mice grow to a much larger size in untreated mice compared with those treated with 0.7 mL/kg per day of oral tetrathiomolybdate. These findings illustrate the ability of tetrathiomolybdate to down-regulate proinflammatory and proangiogenic cytokines in HNSCC. These observations are potentially exciting from a clinical perspective because a global decrease in these cytokines may decrease tumor aggressiveness and reverse the resistance to chemotherapy and radiation therapy seen in this tumor type.

Encapsulated cell device approach for combined electrical stimulation and neurotrophic treatment of the deaf cochlea.

PubMed

Konerding, W S; Janssen, H; Hubka, P; Tornøe, J; Mistrik, P; Wahlberg, L; Lenarz, T; Kral, A; Scheper, V

2017-07-01

Profound hearing impairment can be overcome by electrical stimulation (ES) of spiral ganglion neurons (SGNs) via a cochlear implant (CI). Thus, SGN survival is critical for CI efficacy. Application of glial cell line-derived neurotrophic factor (GDNF) has been shown to reduce SGN degeneration following deafness. We tested a novel method for local, continuous GDNF-delivery in combination with ES via a CI. The encapsulated cell (EC) device contained a human ARPE-19 cell-line, genetically engineered for secretion of GDNF. In vitro, GDNF delivery was stable during ES delivered via a CI. In the chronic in vivo part, cats were systemically deafened and unilaterally implanted into the scala tympani with a CI and an EC device, which they wore for six months. The implantation of control devices (same cell-line not producing GDNF) had no negative effect on SGN survival. GDNF application without ES led to an unexpected reduction in SGN survival, however, the combination of GDNF with initial, short-term ES resulted in a significant protection of SGNs. A tight fibrous tissue formation in the scala tympani of the GDNF-only group is thought to be responsible for the increased SGN degeneration, due to mechanisms related to an aggravated foreign body response. Furthermore, the fibrotic encapsulation of the EC device led to cell death or cessation of GDNF release within the EC device during the six months in vivo. In both in vitro and in vivo, fibrosis was reduced by CI stimulation, enabling the neuroprotective effect of the combined treatment. Thus, fibrous tissue growth limits treatment possibilities with an EC device. For a stable and successful long-term neurotrophic treatment of the SGN via EC devices in human CI users, it would be necessary to make changes in the treatment approach (provision of anti-inflammatories), the EC device surface (reduced cell adhesion) and the ES (initiation prior to fibrosis formation). Copyright © 2017 Elsevier B.V. All rights reserved.

Lewis lung carcinoma progression is facilitated by TIG-3 fibroblast cells.

PubMed

Yamauchi, Yoshikane; Izumi, Yotaro; Asakura, Keisuke; Kawai, Kenji; Wakui, Masatoshi; Ohmura, Mitsuyo; Suematsu, Makoto; Nomori, Hiroaki

2013-09-01

The interactions of tumor cells with stromal fibroblasts influence tumor biology, but the exact mechanisms involved are still unclear. In the present study, we evaluated the effects of a human lung fibroblast cell line, TIG-3, on Lewis lung carcinoma (LLC) cells both in vitro and in vivo. LLC and TIG-3 cells were co-cultured/co-implanted in vitro and in vivo. Cell invasion was assayed. Local tumor growth, as well as lung metastasis, were evaluated after subcutaneous cell co-implantation into NOD/SCID/γ-null (NOG) mice. LLC, and TIG-3 cells were pre-treated with either SB431542, a small molecule TGF-β receptor antagonist, or siRNA for transforming growth factor (TGF)-β before co-culture or co-implantation, and the effects of pre-treatments were compared both in cell culture and in mice. Subcutaneous LLC tumor growth (L group) in NOG mice was significantly increased by co-implantation of TIG-3 cells (L+T group) at four weeks. The number of macroscopic lung metastases was also significantly increased in the L+T group in comparison to the L group. In vitro cell invasion was significantly increased in the L+T group in comparison to the L group. In vitro expression of phosphorylated-SMAD3 was significantly increased in the L+T group in comparison to the L group. Furthermore, pre-treatment with either SB431542 or siRNA for TGF-β reduced the invasiveness both in culture and in mice. This study suggested that in vitro as well as in vivo progression of LLC was facilitated by co-culture/co-implantation with TIG-3 cells, and that this process was at least in part dependent on TGF-β-mediated interactions.

'New embryos' - new challenges for the ethics of stem cell research.

PubMed

Holm, Søren

2008-01-01

Among the many ethical issues raised by human embryonic stem cell research (in the following all references to 'stem cells' should be read as references to human embryonic stem cells), two have gained specific prominence: (1) whether stem cell research is ethically problematic because it entails the destruction of human embryos and (2) what kind of control embryo donors should have over the stem cell lines derived from their embryos. In the present paper, I will analyse how these two issues are engaged by various attempts to derive stem cells from anomalous embryos (e.g. embryos in cleavage arrest, embryos not implanted following pre-implantation genetic diagnosis or embryos created by altered nuclear transfer) or in ways that are claimed to be non-destructive for the embryo (e.g. blastocyst or blastomere biopsy). Copyright 2008 S. Karger AG, Basel.

A Cell Line Producing Recombinant Nerve Growth Factor Evokes Growth Responses in Intrinsic and Grafted Central Cholinergic Neurons

NASA Astrophysics Data System (ADS)

Ernfors, Patrik; Ebendal, Ted; Olson, Lars; Mouton, Peter; Stromberg, Ingrid; Persson, Hakan

1989-06-01

The rat β nerve growth factor (NGF) gene was inserted into a mammalian expression vector and cotransfected with a plasmid conferring resistance to neomycin into mouse 3T3 fibroblasts. From this transfection a stable cell line was selected that contains several hundred copies of the rat NGF gene and produces excess levels of recombinant NGF. Such genetically modified cells were implanted into the rat brain as a probe for in vivo effects of NGF on central nervous system neurons. In a model of the cortical cholinergic deficits in Alzheimer disease, we demonstrate a marked increase in the survival of, and fiber outgrowth from, grafts of fetal basal forebrain cholinergic neurons, as well as stimulation of fiber formation by intact adult intrinsic cholinergic circuits in the cerebral cortex. Adult cholinergic interneurons in intact striatum also sprout vigorously toward implanted fibroblasts. Our results suggest that this model has implications for future treatment of neurodegenerative diseases.

Intracranial implantation with subsequent 3D in vivo bioluminescent imaging of murine gliomas.

PubMed

Abdelwahab, Mohammed G; Sankar, Tejas; Preul, Mark C; Scheck, Adrienne C

2011-11-06

The mouse glioma 261 (GL261) is recognized as an in vivo model system that recapitulates many of the features of human glioblastoma multiforme (GBM). The cell line was originally induced by intracranial injection of 3-methyl-cholantrene into a C57BL/6 syngeneic mouse strain (1); therefore, immunologically competent C57BL/6 mice can be used. While we use GL261, the following protocol can be used for the implantation and monitoring of any intracranial mouse tumor model. GL261 cells were engineered to stably express firefly luciferase (GL261-luc). We also created the brighter GL261-luc2 cell line by stable transfection of the luc2 gene expressed from the CMV promoter. C57BL/6-cBrd/cBrd/Cr mice (albino variant of C57BL/6) from the National Cancer Institute, Frederick, MD were used to eliminate the light attenuation caused by black skin and fur. With the use of albino C57BL/6 mice; in vivo imaging using the IVIS Spectrum in vivo imaging system is possible from the day of implantation (Caliper Life Sciences, Hopkinton, MA). The GL261-luc and GL261-luc2 cell lines showed the same in vivo behavior as the parental GL261 cells. Some of the shared histological features present in human GBMs and this mouse model include: tumor necrosis, pseudopalisades, neovascularization, invasion, hypercellularity, and inflammation (1). Prior to implantation animals were anesthetized by an intraperitoneal injection of ketamine (50 mg/kg), xylazine (5 mg/kg) and buprenorphine (0.05 mg/kg), placed in a stereotactic apparatus and an incision was made with a scalpel over the cranial midline. A burrhole was made 0.1 mm posterior to the bregma and 2.3mm to the right of the midline. A needle was inserted to a depth of 3mm and withdrawn 0.4 mm to a depth of 2.6 mm. Two μl of GL261-luc or GL261-luc2 cells (10(7) cells/ml) were infused over the course of 3 minutes. The burrhole was closed with bonewax and the incision was sutured. Following stereotactic implantation the bioluminescent cells are detectable from the day of implantation and the tumor can be analyzed using the 3D image reconstruction feature of the IVIS Spectrum instrument. Animals receive a subcutaneous injection of 150 μg luciferin /kg body weight 20 min prior to imaging. Tumor burden is quantified using mean tumor bioluminescence over time. Tumor-bearing mice were observed daily to assess morbidity and were euthanized when one or more of the following symptoms are present: lethargy, failure to ambulate, hunched posture, failure to groom, anorexia resulting in >10% loss of weight. Tumors were evident in all of the animals on necropsy.

Intracerebral Cell Implantation: Preparation and Characterization of Cell Suspensions.

PubMed

Rossetti, Tiziana; Nicholls, Francesca; Modo, Michel

2016-01-01

Intracerebral cell transplantation is increasingly finding a clinical translation. However, the number of cells surviving after implantation is low (5-10%) compared to the number of cells injected. Although significant efforts have been made with regard to the investigation of apoptosis of cells after implantation, very little optimization of cell preparation and administration has been undertaken. Moreover, there is a general neglect of the biophysical aspects of cell injection. Cell transplantation can only be an efficient therapeutic approach if an optimal transfer of cells from the dish to the brain can be ensured. We therefore focused on the in vitro aspects of cell preparation of a clinical-grade human neural stem cell (NSC) line for intracerebral cell implantation. NSCs were suspended in five different vehicles: phosphate-buffered saline (PBS), Dulbecco's modified Eagle medium (DMEM), artificial cerebral spinal fluid (aCSF), HypoThermosol, and Pluronic. Suspension accuracy, consistency, and cell settling were determined for different cell volume fractions in addition to cell viability, cell membrane damage, and clumping. Maintenance of cells in suspension was evaluated while being stored for 8 h on ice, at room temperature, or physiological normothermia. Significant differences between suspension vehicles and cellular volume fractions were evident. HypoThermosol and Pluronic performed best, with PBS, aCSF, and DMEM exhibiting less consistency, especially in maintaining a suspension and preserving viability under different storage conditions. These results provide the basis to further investigate these preparation parameters during the intracerebral delivery of NSCs to provide an optimized delivery process that can ensure an efficient clinical translation.

Emitter formation in dendritic web silicon solar cells

NASA Technical Reports Server (NTRS)

Meier, D. L.; Rohatgi, A.; Campbell, R. B.; Alexander, P.; Fonash, S. J.; Singh, R.

1984-01-01

The use of liquid dopants and liquid masks for p-n junction formation in dendritic web solar cells was investigated and found to be equivalent to the use of gaseous dopants and CVD SiO2 masks previously used. This results in a projected cost reduction of 0.02 1980$/Watt for a 25 MW/year production line, and makes possible junction formation processes having a higher throughput than more conventional processes. The effect of a low-energy (0.4 keV) hydrogen ion implant on dendritic web solar cells was also investigated. Such an implant was observed to improve Voc and Jsc substantially. Measurements of internal quantum efficiency suggest that it is the base of the cell, rather than the emitter, which benefits from the hydrogen implant. The diffusion length for electrons in the p-type base increased from 53 microns to 150 microns in one case, with dendritic web cell efficiency being boosted to 15.2 percent. The mechanism by which low-energy hydrogen ions can penetrate deeply into the silicon to effect the observed improvement is not known at this time.

Stem cell therapy for reconstruction of alveolar cleft and trauma defects in adults: A randomized controlled, clinical trial.

PubMed

Bajestan, Mona N; Rajan, Archana; Edwards, Sean P; Aronovich, Sharon; Cevidanes, Lucia H S; Polymeri, Angeliki; Travan, Suncica; Kaigler, Darnell

2017-10-01

Stem cell therapy with bone marrow-derived mesenchymal stem cells is a promising tissue engineering strategy to promote regeneration of craniofacial bone. To determine whether cell therapy with ex vivo expanded stem cell populations would be safe and efficacious in the regeneration of large alveolar defects in patients with a history of cleft palate or craniofacial trauma. Eighteen patients (10 patients with traumatic injury and 8 patients with cleft palate) presenting with missing teeth associated with horizontal alveolar bone deficiencies were included in this randomized controlled clinical trial. Patients were randomized to receive either conventional autogenous block grafts or stem cell therapy. After a healing period of 4 months the treated sites were re-entered and the bone width re-assessed prior to implant placement. Implant stability was evaluated through torque testing of the implant upon insertion and at 6 months postloading. The mean gain in bone width was 1.5 ± 1.5 mm in the stem cell therapy group and 3.3 ± 1.4 mm in the control group. Overall, bone gain was higher in trauma patients as compared to patients with cleft palate, for both the control and the stem cell therapy groups. Most postoperative complications were wound dehiscences and incision line openings. Implants were placed successfully in 5 out of 10 patients in the stem cell therapy group and in all 8 patients in the control group. One implant from the control/cleft palate group failed before loading, while the rest of the implants were loaded successfully and remained stable at 6 months. The patients who did not receive implants were re-treated with autogenous block bone graft. The ability of stem cells to treat large alveolar defects is safe, yet, their ability to completely reconstitute large alveolar defects is limited. This approach requires further optimization to meet the outcomes seen using current methods to treat large defects, particularly those resultant of cleft palate. © 2017 Wiley Periodicals, Inc.

Downregulation of Sp1 by Minnelide leads to decrease in HSP70 and decrease in tumor burden of gastric cancer.

PubMed

Arora, Nivedita; Alsaied, Osama; Dauer, Patricia; Majumder, Kaustav; Modi, Shrey; Giri, Bhuwan; Dudeja, Vikas; Banerjee, Sulagna; Von Hoff, Daniel; Saluja, Ashok

2017-01-01

Gastric cancer is the third leading cause of cancer related mortality worldwide with poor survival rates. Even though a number of chemotherapeutic compounds have been used against this disease, stomach cancer has not been particularly sensitive to these drugs. In this study we have evaluated the effect of triptolide, a naturally derived diterpene triepoxide and its water soluble pro-drug Minnelide on several gastric adenocarcinoma cell lines both as monotherapy and in combination with CPT-11. Gastric cancer cell lines MKN28 and MKN45 were treated with varying doses of triptolide in vitro. Cell viability was measured using MTT based assay kit. Apoptotic cell death was assayed by measuring caspase activity. Effect of the triptolide pro-drug, Minnelide, was evaluated by implanting the gastric cancer cells subcutaneously in athymic nude mice. Gastric cancer cell lines MKN28 and MKN45 cells exhibited decreased cell viability and increased apoptosis when treated with varying doses of triptolide in vitro. When implanted in athymic nude mice, treatment with Minnelide reduced tumor burden in both MKN28 derived tumors as well as MKN45 derived tumors. Additionally, we also evaluated Minnelide as a single agent and in combination with CPT-11 in the NCI-N87 human gastric tumor xenograft model. Our results indicated that the combination of Minnelide with CPT-11 resulted in significantly smaller tumors compared to control. These studies are extremely encouraging as Minnelide is currently undergoing phase 1 clinical trials for gastrointestinal cancers.

Toxicity testing of urinary catheters.

PubMed

Talja, M; Andersson, L C; Ruutu, M; Alfthan, O

1985-10-01

The tissue toxicity of 23 urinary catheter batches (6 latex and 2 non-latex brands) was tested in vitro and in vivo. In vitro, a human T-cell leukemia line (JM) was cultured in the presence of different concentrations of eluates made from the catheters. The cytotoxicity of the eluates was assessed from their ability to inhibit DNA synthesis measured by incorporation of 3H-thymidine. In vivo, two methods were used. Strips of catheters were implanted into the rabbit dorsal muscle and pieces of catheters were implanted into the rat peritoneal cavity. After four days, the foreign body reaction, type of inflammation and necrosis were quantified macroscopically and by light microscopy. The results of the in vitro cytotoxicity test were correlated with those of in vivo methods. The rat peritoneal implantation test correlated better with the cell culture test (P less than 0.01) than with the rabbit muscle implantation test (P less than 0.05). Based on the clinical experience of urethral stricture complications caused by urinary catheters, catheters yielding eluate which at 30% dilution inhibited 50% DNA synthesis were regarded as toxic. According to this, the rabbit muscle implantation test was not reliable in testing the tissue toxicity of urinary catheters, while the cell culture test was quantitative and seemed to correlate with both the rat peritoneal implantation test and with the clinical complications observed.

Effect of polychromatic visible light on proliferation of tumor cells under conditions in vitro and in vivo—after implantation to experimental animals

NASA Astrophysics Data System (ADS)

Knyazev, N. A.; Samoilova, K. A.; Filatova, N. A.; Galaktionova, A. A.

2009-06-01

The question of the character of effect of visible and near infrared (IR) radiation of Sun and artificial sources on growth of malignant tumors remains open due to controversy and a relatively small amount of available data, which restricts use of this most important environmental and the efficient physiotherapeutic factors at various human pathological states and first of all at the rehabilitation of oncological patients after radical methods of cancer treatment (surgical removal of tumor, intensive medication and radiation therapy), when immunomodulatory antiinflamatory, wound-healing and analgesic properties of visible and near IR light can be drawn. In the present work, using polychromatic visible light, close to this dominant component of the terrestrial solar radiation (380-750 nm, 40 mW/cm2) we irradiated tumor cells of the murine hepatoma (MH-22a line) under conditions in vitro (the monolayer of cells in Petri dishes) and in vivo (after subcutaneous implantation of these cells to mice of the C3HA line). A high resistance of the MH-22a cells to polychromatic visible radiation has been established under conditions in vitro: irradiation at dose 24 J/cm2 did not inhibit their proliferation whereas a dose of 9.6 J/cm2, stimulated statistically significantly proliferation of the cells (by 24-40%). However, stimulation of the tumor cell proliferation, did not develop under conditions in vivo, when mice were irradiated (9.6 J/cm2)—daily for 5 days before the implantation of tumor cells and for 5 days after implantation (in the latter case there was a probability of transcutaneous irradiation of tumor cells). By implanting to the animals of tumor cells at various concentrations (from 2ṡ105 to 25ṡ103 cells per mouse), we did not revealed at any of 10 terms of observations for 41-45 days both an increase of incidence of the tumor development and acceleration of tumor growth as well as a decrease of the animals survival as compared with group of non-irradiated animals. Moreover, there was recorded a decrease of incidence of the tumor development—by 16-24%, downregulation of the tumor growth rate—on average, by 40% and an increase of survival of the animals (by 20%). Thus, for the first time, an antitumor effect of polychromatic visible light has been shown at its application on the body surface of experimental animals.

Plasma Immersion Ion Implantation for Interdigitated Back Passivated Contact (IBPC) Solar Cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Young, David L.; Nemeth, William; LaSalvia, Vincenzo

2016-11-21

We present progress to develop low-cost interdigitated back contact solar cells with pc-Si/SiO2/c-Si passivated contacts formed by plasma immersion ion implantation (PIII). PIII is a lower-cost implantation technique than traditional beam-line implantation due to its simpler design, lower operating costs, and ability to run high doses (1E14-1E18 cm-2) at low ion energies (20 eV-10 keV). These benefits make PIII ideal for high throughput production of patterned passivated contacts, where high-dose, low-energy implantations are made into thin (20-200 nm) a-Si layers instead of into the wafer itself. For this work symmetric passivated contact test structures grown on n-Cz wafers with PH3more » PIII doping gave implied open circuit voltage (iVoc) values of 730 mV with Jo values of 2 fA/cm2. Samples doped with B2H6 gave iVoc values of 690 mV and Jo values of 24 fA/cm2, outperforming BF3 doping, which gave iVoc values in the 660-680 mV range. Samples were further characterized by photoluminescence and SIMS depth profiles. Initial IBPC cell results are presented.« less

Imaging of bioluminescent LNCaP-luc-M6 tumors: a new animal model for the study of metastatic human prostate cancer.

PubMed

Scatena, Caroline D; Hepner, Mischa A; Oei, Yoko A; Dusich, Joan M; Yu, Shang-Fan; Purchio, Tony; Contag, Pamela R; Jenkins, Darlene E

2004-05-15

Animal experiments examining hormone-sensitive metastatic prostate cancer using the human LNCaP cell line have been limited to endpoint analyses. To permit longitudinal studies, we generated a luciferase-expressing cell line and used bioluminescent imaging (BLI) to non-invasively monitor the in vivo growth of primary LNCaP tumors and metastasis. LNCaP.FGC cells were transfected to constitutively express firefly luciferase. LNCaP-luc-M6 cells were tested for bioluminescent signal intensity and hormone responsiveness in vitro. The cells were implanted in subcutaneous and orthotopic sites in SCID-bg mice and imaged over time. The LNCaP-luc-M6 cells formed subcutaneous and orthotopic tumors in SCID-bg mice, and nearly all tumor-bearing animals developed pulmonary metastases. Early detection and temporal growth of primary tumors and metastatic lesions was successfully monitored by BLI. The LNCaP-luc-M6 cell line is a bioluminescent, hormone-sensitive prostate cancer cell line applicable for BLI studies to non-invasively monitor subcutaneous and orthotopic prostate tumor growth and metastasis in vivo. Copyright 2004 Wiley-Liss, Inc.

Microcalcifications in breast cancer: novel insights into the molecular mechanism and functional consequence of mammary mineralisation

PubMed Central

Cox, R F; Hernandez-Santana, A; Ramdass, S; McMahon, G; Harmey, J H; Morgan, M P

2012-01-01

Background: Mammographic microcalcifications represent one of the most reliable features of nonpalpable breast cancer yet remain largely unexplored and poorly understood. Methods: We report a novel model to investigate the in vitro mineralisation potential of a panel of mammary cell lines. Primary mammary tumours were produced by implanting tumourigenic cells into the mammary fat pads of female BALB/c mice. Results: Hydroxyapatite (HA) was deposited only by the tumourigenic cell lines, indicating mineralisation potential may be associated with cell phenotype in this in vitro model. We propose a mechanism for mammary mineralisation, which suggests that the balance between enhancers and inhibitors of physiological mineralisation are disrupted. Inhibition of alkaline phosphatase and phosphate transport prevented mineralisation, demonstrating that mineralisation is an active cell-mediated process. Hydroxyapatite was found to enhance in vitro tumour cell migration, while calcium oxalate had no effect, highlighting potential consequences of calcium deposition. In addition, HA was also deposited in primary mammary tumours produced by implanting the tumourigenic cells into the mammary fat pads of female BALB/c mice. Conclusion: This work indicates that formation of mammary HA is a cell-specific regulated process, which creates an osteomimetic niche potentially enhancing breast tumour progression. Our findings point to the cells mineralisation potential and the microenvironment regulating it, as a significant feature of breast tumour development. PMID:22233923

In vitro modeling of human pancreatic duct epithelial cell transformation defines gene expression changes induced by K-ras oncogenic activation in pancreatic carcinogenesis.

PubMed

Qian, Jiaying; Niu, Jiangong; Li, Ming; Chiao, Paul J; Tsao, Ming-Sound

2005-06-15

Genetic analysis of pancreatic ductal adenocarcinomas and their putative precursor lesions, pancreatic intraepithelial neoplasias (PanIN), has shown a multistep molecular paradigm for duct cell carcinogenesis. Mutational activation or inactivation of the K-ras, p16(INK4A), Smad4, and p53 genes occur at progressive and high frequencies in these lesions. Oncogenic activation of the K-ras gene occurs in >90% of pancreatic ductal carcinoma and is found early in the PanIN-carcinoma sequence, but its functional roles remain poorly understood. We show here that the expression of K-ras(G12V) oncogene in a near diploid HPV16-E6E7 gene immortalized human pancreatic duct epithelial cell line originally derived from normal pancreas induced the formation of carcinoma in 50% of severe combined immunodeficient mice implanted with these cells. A tumor cell line established from one of these tumors formed ductal cancer when implanted orthotopically. These cells also showed increased activation of the mitogen-activated protein kinase, AKT, and nuclear factor-kappaB pathways. Microarray expression profiling studies identified 584 genes whose expression seemed specifically up-regulated by the K-ras oncogene expression. Forty-two of these genes have been reported previously as differentially overexpressed in pancreatic cancer cell lines or primary tumors. Real-time PCR confirmed the overexpression of a large number of these genes. Immunohistochemistry done on tissue microarrays constructed from PanIN and pancreatic cancer samples showed laminin beta3 overexpression starting in high-grade PanINs and occurring in >90% of pancreatic ductal carcinoma. The in vitro modeling of human pancreatic duct epithelial cell transformation may provide mechanistic insights on gene expression changes that occur during multistage pancreatic duct cell carcinogenesis.

Hydroxyapatite nanocrystals functionalized with alendronate as bioactive components for bone implant coatings to decrease osteoclastic activity

NASA Astrophysics Data System (ADS)

Bosco, Ruggero; Iafisco, Michele; Tampieri, Anna; Jansen, John A.; Leeuwenburgh, Sander C. G.; van den Beucken, Jeroen J. J. P.

2015-02-01

The integration of bone implants within native bone tissue depends on periprosthetic bone quality, which is severely decreased in osteoporotic patients. In this work, we have synthesized bone-like hydroxyapatite nanocrystals (nHA) using an acid-base neutralization reaction and analysed their physicochemical properties. Subsequently, we have functionalized the nHA with alendronate (nHAALE), a well-known bisphosphonate drug used for the treatment of osteoporosis. An in vitro osteoclastogenesis test was carried out to evaluate the effect of nHAALE on the formation of osteoclast-like cells from monocytic precursor cells (i.e. RAW264.7 cell line) showing that nHAALE significantly promoted apoptosis of osteoclast-like cells. Subsequently, nHA and nHAALE were deposited on titanium disks using electrospray deposition (ESD), for which characterisation of the deposited coatings confirmed the presence of alendronate in nHAALE coatings with nanoscale thickness of about 700 nm. These results indicate that alendronate linked to hydroxyapatite nanocrystals has therapeutic potential and nHAALE can be considered as an appealing coating constituent material for orthopaedic and oral implants for application in osteoporotic patients.

Use of NASA Bioreactor in Engineering Tissue for Bone Repair

NASA Technical Reports Server (NTRS)

Duke, Pauline

1998-01-01

This study was proposed in search for a new alternative for bone replacement or repair. Because the systems commonly used in repair of bony defects form bone by going through a cartilaginous phase, implantation of a piece of cartilage could enhance the healing process by having a more advanced starting point. However, cartilage has seldom been used to replace bone due, in part, to the limitations in conventional culture systems that did not allow production of enough tissue for implants. The NASA-developed bioreactors known as STLV (Slow Turning Lateral Vessel) provide homogeneous distribution of cells, nutrients, and waste products, with less damaging turbulence and shear forces than conventional systems. Cultures under these conditions have higher growth rates, viability, and longevity, allowing larger "tissue-like" aggregates to form, thus opening the possibilities of producing enough tissue for implantation, along with the inherent advantages of in vitro manipulations. To assure large numbers of cells and to eliminate the use of timed embryos, we proposed to use an immortalized mouse limb bud cell line as the source of cells.

Human Endometrial CD98 Is Essential for Blastocyst Adhesion

PubMed Central

Domínguez, Francisco; Simón, Carlos; Quiñonero, Alicia; Ramírez, Miguel Ángel; González-Muñoz, Elena; Burghardt, Hans; Cervero, Ana; Martínez, Sebastián; Pellicer, Antonio; Palacín, Manuel; Sánchez-Madrid, Francisco; Yáñez-Mó, María

2010-01-01

Background Understanding the molecular basis of embryonic implantation is of great clinical and biological relevance. Little is currently known about the adhesion receptors that determine endometrial receptivity for embryonic implantation in humans. Methods and Principal Findings Using two human endometrial cell lines characterized by low and high receptivity, we identified the membrane receptor CD98 as a novel molecule selectively and significantly associated with the receptive phenotype. In human endometrial samples, CD98 was the only molecule studied whose expression was restricted to the implantation window in human endometrial tissue. CD98 expression was restricted to the apical surface and included in tetraspanin-enriched microdomains of primary endometrial epithelial cells, as demonstrated by the biochemical association between CD98 and tetraspanin CD9. CD98 expression was induced in vitro by treatment of primary endometrial epithelial cells with human chorionic gonadotropin, 17-β-estradiol, LIF or EGF. Endometrial overexpression of CD98 or tetraspanin CD9 greatly enhanced mouse blastocyst adhesion, while their siRNA-mediated depletion reduced the blastocyst adhesion rate. Conclusions These results indicate that CD98, a component of tetraspanin-enriched microdomains, appears to be an important determinant of human endometrial receptivity during the implantation window. PMID:20976164

Inner retinal preservation in rat models of retinal degeneration implanted with subretinal photovoltaic arrays.

PubMed

Light, Jacob G; Fransen, James W; Adekunle, Adewumi N; Adkins, Alice; Pangeni, Gobinda; Loudin, James; Mathieson, Keith; Palanker, Daniel V; McCall, Maureen A; Pardue, Machelle T

2014-11-01

Photovoltaic arrays (PVA) implanted into the subretinal space of patients with retinitis pigmentosa (RP) are designed to electrically stimulate the remaining inner retinal circuitry in response to incident light, thereby recreating a visual signal when photoreceptor function declines or is lost. Preservation of inner retinal circuitry is critical to the fidelity of this transmitted signal to ganglion cells and beyond to higher visual targets. Post-implantation loss of retinal interneurons or excessive glial scarring could diminish and/or eliminate PVA-evoked signal transmission. As such, assessing the morphology of the inner retina in RP animal models with subretinal PVAs is an important step in defining biocompatibility and predicting success of signal transmission. In this study, we used immunohistochemical methods to qualitatively and quantitatively compare inner retinal morphology after the implantation of a PVA in two RP models: the Royal College of Surgeons (RCS) or transgenic S334ter-line 3 (S334ter-3) rhodopsin mutant rat. Two PVA designs were compared. In the RCS rat, we implanted devices in the subretinal space at 4 weeks of age and histologically examined them at 8 weeks of age and found inner retinal morphology preservation with both PVA devices. In the S334ter-3 rat, we implanted devices at 6-12 weeks of age and again, inner retinal morphology was generally preserved with either PVA design 16-26 weeks post-implantation. Specifically, the length of rod bipolar cells and numbers of cholinergic amacrine cells were maintained along with their characteristic inner plexiform lamination patterns. Throughout the implanted retinas we found nonspecific glial reaction, but none showed additional glial scarring at the implant site. Our results indicate that subretinally implanted PVAs are well-tolerated in rodent RP models and that the inner retinal circuitry is preserved, consistent with our published results showing implant-evoked signal transmission. Published by Elsevier Ltd.

Optical imaging of tumor cells in hollow fibers: evaluation of the antitumor activities of anticancer drugs and target validation.

PubMed

Zhang, Guo-Jun; Chen, Tsing-Bau; Bednar, Bohumil; Connolly, Brett M; Hargreaves, Richard; Sur, Cyrille; Williams, David L

2007-08-01

The in vivo hollow fiber assay, in which semipermeable hollow fibers filled with tumor cells, are implanted into animals, was originally developed to screen for anticancer compounds before assessment in more complex tumor models. To enhance screening and evaluation of anticancer drugs, we have applied optical imaging technology to this assay. To demonstrate that tumor cells inside hollow fibers can communicate with the host mice, we have used fluorescence imaging in vivo and CD31 immunostaining ex vivo to show that angiogenesis occurs around cell-filled hollow fibers by 2 weeks after subcutaneous implantation. Bioluminescence imaging has been used to follow the number of luciferase-expressing tumor cells within implanted hollow fibers; proliferation of those cells was found to be significantly inhibited by docetaxel or irinotecan. We also used bioluminescence imaging of hollow fibers to monitor the nuclear factor kappaB (NFkappaB) pathway in vivo; NFkappaB activation by lipopolysaccharide and tumor necrosis factor-alpha was evaluated in tumor cell lines genetically engineered to express luciferase controlled by an NFkappaB-responsive element. These results demonstrate that optical imaging of hollow fibers containing reporter tumor cells can be used for the rapid and accurate evaluation of antitumor activities of anticancer drugs and for measurement of molecular pathways.

The automated array assembly task of the low-cost silicon solar array project, phase 2

NASA Technical Reports Server (NTRS)

Coleman, M. G.; Pryor, R. A.; Sparks, T. G.; Legge, R.; Saltzman, D. L.

1980-01-01

Several specific processing steps as part of a total process sequence for manufacturing silicon solar cells were studied. Ion implantation was identified as the preferred process step for impurity doping. Unanalyzed beam ion implantation was shown to have major cost advantages over analyzed beam implantation. Further, high quality cells were fabricated using a high current unanalyzed beam. Mechanically masked plasma patterning of silicon nitride was shown to be capable of forming fine lines on silicon surfaces with spacings between mask and substrate as great as 250 micrometers. Extensive work was performed on advances in plated metallization. The need for the thick electroless palladium layer was eliminated. Further, copper was successfully utilized as a conductor layer utilizing nickel as a barrier to copper diffusion into the silicon. Plasma etching of silicon for texturing and saw damage removal was shown technically feasible but not cost effective compared to wet chemical etching techniques.

Establishment and Characterization of a Highly Tumourigenic and Cancer Stem Cell Enriched Pancreatic Cancer Cell Line as a Well Defined Model System

PubMed Central

Fredebohm, Johannes; Boettcher, Michael; Eisen, Christian; Gaida, Matthias M.; Heller, Anette; Keleg, Shereen; Tost, Jörg; Greulich-Bode, Karin M.; Hotz-Wagenblatt, Agnes; Lathrop, Mark; Giese, Nathalia A.; Hoheisel, Jörg D.

2012-01-01

Standard cancer cell lines do not model the intratumoural heterogeneity situation sufficiently. Clonal selection leads to a homogeneous population of cells by genetic drift. Heterogeneity of tumour cells, however, is particularly critical for therapeutically relevant studies, since it is a prerequisite for acquiring drug resistance and reoccurrence of tumours. Here, we report the isolation of a highly tumourigenic primary pancreatic cancer cell line, called JoPaca-1 and its detailed characterization at multiple levels. Implantation of as few as 100 JoPaca-1 cells into immunodeficient mice gave rise to tumours that were histologically very similar to the primary tumour. The high heterogeneity of JoPaca-1 was reflected by diverse cell morphology and a substantial number of chromosomal aberrations. Comparative whole-genome sequencing of JoPaca-1 and BxPC-3 revealed mutations in genes frequently altered in pancreatic cancer. Exceptionally high expression of cancer stem cell markers and a high clonogenic potential in vitro and in vivo was observed. All of these attributes make this cell line an extremely valuable model to study the biology of and pharmaceutical effects on pancreatic cancer. PMID:23152778

Implanting intra-abdominal radiotransmitters with external whip antennas in ducks

USGS Publications Warehouse

Korschgen, C.E.; Kenow, K.P.; Gendron-Fitzpatrick, A.; Green, W.L.; Dein, F.J.

1996-01-01

We developed and evaluated a surgical procedure for implanting intra-abdominal radiotransmitters with external whip antennas in captive mallards (Anas platyrhynchos). Transmitters were implanted in the abdominal cavity and the antennas exited through the caudal abdominal wall and skin. Birds with implanted transmitters developed mild to moderate localized air sac reactions. These reactions involved adhesions of the right anterior abdominal air sac to the liver with contractions around the transmitters and antenna catheters. The adhesions were reinforced by a proliferation of connective tissue and lined by multinucleated giant cells (foreign body reaction). Casual observation indicated that neither behavior nor activity of the birds was altered by the histological reaction to the transmitter implant. No increase in systemic lesions (particularly liver or kidney) could be correlated with the histological reactions. Our evaluations indicate that the procedure is a reliable method for radiomarking ducks and the technique has been successfully used in 2 field studies.

Silver oxide-containing hydroxyapatite coating supports osteoblast function and enhances implant anchorage strength in rat femur.

PubMed

Eto, Shuichi; Miyamoto, Hiroshi; Shobuike, Takeo; Noda, Iwao; Akiyama, Takayuki; Tsukamoto, Masatsugu; Ueno, Masaya; Someya, Shinsuke; Kawano, Shunsuke; Sonohata, Motoki; Mawatari, Masaaki

2015-09-01

Antibacterial silver with hydroxyapatite (Ag-HA) is a promising coating material for imparting antibacterial properties to implants. We previously reported that 3% (w/w) silver with HA (3% Ag-HA) has both antibacterial activity and osteoconductivity. In this study, we investigated the effects of Ag-HA on the in vitro osteoblast function and the in vivo anchorage strength and osteoconductivity of implants. Production of the osteoblast marker alkaline phosphatase, but not cytotoxicity, was observed in cells of the osteoblast cell line MC3T3-E1 cultured on the 3% Ag-HA-coated surface. These results were similar to those observed with silver-free HA coating. In contrast, a significant high level of cytotoxicity was observed when the cells were cultured on a 50% Ag-HA-coated surface. The anchorage strength of implants inserted into the femur of Sprague-Dawley (SD) rats was enhanced by coating the implants with 3% Ag-HA. On the 3% Ag-HA-coated surface, both metaphyseal and diaphyseal areas were largely covered with new bone and had adequate osteoconductivity. These results suggest that 3% Ag-HA, like conventional HA, promotes osteogenesis by supporting osteoblast viability and function and thereby contributes to sufficient anchorage strength of implants. Application of 3% Ag-HA, which combines the osteoconductivity of HA and the antibacterial activity of silver, to prosthetic joints will help prevent postoperative infections. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

Microengineering of artificial capillaries

NASA Astrophysics Data System (ADS)

Moldovan, Nicanor I.

2002-11-01

Biocompatibility and functionality of implanted inorganic medical devices is limited by the local reaction of the organism, with a recently recognized contribution of nearby microvasculature. We explored the possibility to microengineer pre-embedded microvascular networks in the surface of inorganic devices. The implants would thus function as carriers of pre-assembled microvessels, ready to expand, and contribute to local angiogenesis. Based on our own studies on the role played by local microtopography in angiogenesis (the tunneling concept), we have shown the feasibility of endothelial cells cultivation in grooves created on the surface of the materials to be implanted, either polymeric or silicon. In order to develop this new technology, we devised an in situ approach to the study of the cellular behavior on micropatterned surfaces, by use of Laser Scanning Cytometry (LSC). In this report I will present our results regarding the LSC analysis of endothelial cells cultivated in grooves made on the surface of silicon wafers, and the consequences of this treatment on endothelial physiology. When comparing the growth of endothelial cells on line patterned and non-patterned areas, in terms of several morphological parameters of cell nuclei, our data support the conclusion that lateral confinement of endothelial cells induces a quiescent state, possibly by inhibiting their ability to proliferate.

Tissue response to surface-treated tantalum implants: preliminary observations in primates.

PubMed

Meenaghan, M A; Natiella, J R; Moresi, J L; Flynn, H E; Wirth, J E; Baier, R E

1979-07-01

Samples of capacitor grade tantalum were surface-treated by a variety of methods. These surface treatments allowed testing of the same basic material which was mill-finished, metallurgically polished, electrochemically oxidized, sintered with a porous surface, and glow-discharged. Surface characterization was accomplished by contact angle measurements, Scanning Electron Microscopy, energy-dispensed x-ray analysis, and internal reflection spectroscopy. Subsequent to characterization, the material was surgically implanted in the subperiosteal region of the mandible, the buccal mucosa, and the subcutaneous paravertebral region of the back of Macaca speciosa (stumptail monkey). The tissue reaction at intervals of up to three weeks was evaluated morphologically and ultrastructurally. Significant differences in tissue response were noted at the interfaces with glow-discharge-treated versus lower surface energy samples. Adjacent to the glow-discharge-treated implants, two distinct tissue zones were identified. Zone No. 1, nearest the implant, exhibited an increased cellularity. This consisted of 4-5 layers of highly active mesenchymal cells or fibroblast-like cells with spindle-shaped nuclei and prominent cytoplasmic features. At various foci along the interface, hyperchromatic nuclear forms were noted to project into the space left by removal of the implant. These observations, coupled with a predominance of intercellular ground-substance material and less collagen at the interface, may indicate some form of bioadhesion. The deeper Zone No. 2 was 2-3 times as thick consisted of typical fibroblastic cells with a lamellar configuration, bordered by an occasional delicate-lined space. Independent of implantation site or surface texture, all other implants showed occasional multinucleated giant cells and a decrease in the cellular character of Zone No. 1. Both zones were reduced in thickness and composed of more mature fibroblasts. Some specimens exhibited intracytoplasmic vacuolization. It may be concluded, therefore, that surface-free energy of the implanted specimens played a significant role in inducing differential tissue response to otherwise similar pure metal samples.

Preventing hypoxia-induced cell death in beta cells and islets via hydrolytically activated, oxygen-generating biomaterials

PubMed Central

Pedraza, Eileen; Coronel, Maria M.; Fraker, Christopher A.; Ricordi, Camillo; Stabler, Cherie L.

2012-01-01

A major hindrance in engineering tissues containing highly metabolically active cells is the insufficient oxygenation of these implants, which results in dying or dysfunctional cells in portions of the graft. The development of methods to increase oxygen availability within tissue-engineered implants, particularly during the early engraftment period, would serve to allay hypoxia-induced cell death. Herein, we designed and developed a hydrolytically activated oxygen-generating biomaterial in the form of polydimethylsiloxane (PDMS)-encapsulated solid calcium peroxide, PDMS-CaO2. Encapsulation of solid peroxide within hydrophobic PDMS resulted in sustained oxygen generation, whereby a single disk generated oxygen for more than 6 wk at an average rate of 0.026 mM per day. The ability of this oxygen-generating material to support cell survival was evaluated using a β cell line and pancreatic rat islets. The presence of a single PDMS-CaO2 disk eliminated hypoxia-induced cell dysfunction and death for both cell types, resulting in metabolic function and glucose-dependent insulin secretion comparable to that in normoxic controls. A single PDMS-CaO2 disk also sustained enhanced β cell proliferation for more than 3 wk under hypoxic culture conditions. Incorporation of these materials within 3D constructs illustrated the benefits of these materials to prevent the development of detrimental oxygen gradients within large implants. Mathematical simulations permitted accurate prediction of oxygen gradients within 3D constructs and highlighted conditions under which supplementation of oxygen tension would serve to benefit cellular viability. Given the generality of this platform, the translation of these materials to other cell-based implants, as well as ischemic tissues in general, is envisioned. PMID:22371586

The isolation and characterization of a telomerase immortalized goat trophoblast cell line.

PubMed

Dong, F; Huang, Y; Li, W; Zhao, X; Zhang, W; Du, Q; Zhang, H; Song, X; Tong, D

2013-12-01

Trophoblast cells play vital roles in the processes of embryonic implantation and placentation. Many toxicological compounds can induce the malfunction of trophoblast cells, resulting in implantation failure or early embryonic loss. The finite lifespan of primary trophoblast cells limits investigation of the long-term effects of some toxicological compounds on trophoblast cells in vitro. In this study, primary goat trophoblast cells were purified by density gradient centrifugation and specific immuno-affinity purification. Then, the purified cells were immortalized through transfection of a plasmid containing the human telomerase reverse transcriptase (hTERT) gene. hTERT-transfected goat trophoblast cells (hTERT-GTCs) could steadily express hTERT gene and exhibit higher telomerase activity, and persistently proliferate without any signs of senescence up to 50 passages. The immortalized goat trophoblast cells still possessed the basic and key properties of normal primary goat trophoblast cells to express the specific intracellular marker cytokeratin 7 (CK-7) and secrete chorionic gonadotrophin β-subunit (CG-β) and placental lactogen (PL). Further studies showed that the immortalized goat trophoblast cells expressed vimentin and non-classical MHC class I antigen and exhibited invasive phenotype, suggesting that the immortalized goat trophoblasts resembled human extravillous trophoblasts. In addition, this cell line did not show neoplastic transformation either in vivo or in vitro. We concluded the immortalized goat trophoblast cells by hTERT transfection retained the basic and key characteristics of primary trophoblast cells and may provide a useful model to study the effects of some toxicological compounds on trophoblast cells. Copyright © 2013 Elsevier Ltd. All rights reserved.

In vitro biocorrosion of Ti-6Al-4V implant alloy by a mouse macrophage cell line.

PubMed

Lin, Hsin-Yi; Bumgardner, Joel D

2004-03-15

Corrosion of implant alloys releasing metal ions has the potential to cause adverse tissue reactions and implant failure. We hypothesized that macrophage cells and their released reactive chemical species (RCS) affect the alloy's corrosion properties. A custom cell culture corrosion box was used to evaluate how cell culture medium, macrophage cells and RCS altered the Ti-6Al-4V corrosion behaviors in 72 h and how corrosion products affected the cells. There was no difference in the charge transfer in the presence (75.2 +/- 17.7 mC) and absence (62.3 +/- 18.8 mC) of cells. The alloy had the lowest charge transfer (28.2 +/- 4.1 mC) and metal ion release (Ti < 10 ppb, V < 2 ppb) with activated cells (releasing RCS) compared with the other two conditions. This was attributed to an enhancement of the surface oxides by RCS. Metal ion release was very low (Ti < 20 ppb, V < 10 ppb) with nonactivated cells and did not change cell morphology, viability, and NO and ATP release compared with controls. However, IL-1beta released from the activated cells and the proliferation of nonactivated cells were greater on the alloy than the controls. In summary, macrophage cells and RCS reduced the corrosion of Ti-6Al-4V alloys as hypothesized. These data are important in understanding host tissue-material interactions. Copyright 2004 Wiley Periodicals, Inc. J Biomed Mater Res 68A: 717-724, 2004

Implant therapy in the esthetic zone: smile line assessment.

PubMed

Kourkouta, Stella

2011-04-01

Assessment of the smile or lip line is imperative when implant therapy is carried out in the esthetic zone. The smile is generally defined as high, average, or low. Females are reported to have higher lip lines than males, which means that they are at greater risk when placing and restoring implants in the esthetic zone. Maximum upper lip elevation, usually observed during a strained posed smile, should be assessed. This paper discusses some clinical observations and concepts in relation to smile line assessment for implant therapy in the esthetic zone. (Int J Periodontics Restorative Dent 2011;31:195-201.).

Genetically fluorescent melanoma bone and organ metastasis models.

PubMed

Yang, M; Jiang, P; An, Z; Baranov, E; Li, L; Hasegawa, S; Al-Tuwaijri, M; Chishima, T; Shimada, H; Moossa, A R; Hoffman, R M

1999-11-01

We report here the establishment and metastatic properties of bright, highly stable, green fluorescent protein (GFP) expression transductants of the B16 mouse malignant melanoma cell line and the LOX human melanoma line. The highly fluorescent malignant melanoma cell lines allowed the visualization of skeletal and multiorgan metastases after i.v. injection of B16 cells in C57BL/6 mice and intradermal injection of LOX cells in nude mice. The melanoma cell lines were transduced with the pLEIN expression retroviral vector containing the GFP and neomycin resistance genes. Stable B16F0 and LOX clones expressing high levels of GFP were selected stepwise in vitro in levels of G418 of up to 800 microg/ml. Extensive bone and bone marrow metastases of B16F0 were visualized by GFP expression when the animals were sacrificed 3 weeks after cell implantation. Metastases for both cell lines were visualized in many organs, including the brain, lung, pleural membrane, liver, kidney, adrenal gland, lymph nodes, skeleton, muscle, and skin by GFP fluorescence. This is the first observation of experimental skeletal metastases of melanoma, which was made possible by GFP expression. These models should facilitate future studies of the mechanism and therapy of bone and multiorgan metastasis of melanoma.

Hepatocyte growth factor secreted by ovarian cancer cells stimulates peritoneal implantation via the mesothelial-mesenchymal transition of the peritoneum.

PubMed

Nakamura, Michihiko; Ono, Yoshihiro J; Kanemura, Masanori; Tanaka, Tomohito; Hayashi, Masami; Terai, Yoshito; Ohmichi, Masahide

2015-11-01

A current working model for the metastatic process of ovarian carcinoma suggests that cancer cells are shed from the ovarian tumor into the peritoneal cavity and attach to the layer of mesothelial cells that line the inner surface of the peritoneum, and several studies suggest that hepatocyte growth factor (HGF) plays an important role in the dissemination of ovarian cancer. Our objectives were to evaluate the HGF expression of ovarian cancer using clinical data and assess the effect of HGF secreted from human ovarian cancer cells to human mesothelial cells. HGF expression was immunohistochemically evaluated in 165 epithelial ovarian cancer patients arranged as tissue microarrays. HGF expression in four ovarian cancer cell lines was evaluated by using semi-quantitative polymerase chain reaction, Western blotting and enzyme-linked immunosorbent assay. The effect of ovarian cancer cell derived HGF to the human mesothelial cells was assessed by using morphologic analysis, Western blotting and cell invasion assay. The effect of HGF on ovarian cancer metastasis was assessed by using in vivo experimental model. The clinical data showed a significantly high correlation between the HGF expression and the cancer stage. The in vivo and in vitro experimental models revealed that HGF secreted by ovarian cancer cells induces the mesothelial-to-mesenchymal transition and stimulates the invasion of mesothelial cells. Furthermore, manipulating the HGF activity affected the degree of dissemination and ascite formation. We demonstrated that HGF secreted by ovarian cancer cells plays an important role in cancer peritoneal implantation. Copyright © 2015 Elsevier Inc. All rights reserved.

Generation of stable PDX derived cell lines using conditional reprogramming.

PubMed

Borodovsky, Alexandra; McQuiston, Travis J; Stetson, Daniel; Ahmed, Ambar; Whitston, David; Zhang, Jingwen; Grondine, Michael; Lawson, Deborah; Challberg, Sharon S; Zinda, Michael; Pollok, Brian A; Dougherty, Brian A; D'Cruz, Celina M

2017-12-06

Efforts to develop effective cancer therapeutics have been hindered by a lack of clinically predictive preclinical models which recapitulate this complex disease. Patient derived xenograft (PDX) models have emerged as valuable tools for translational research but have several practical limitations including lack of sustained growth in vitro. In this study, we utilized Conditional Reprogramming (CR) cell technology- a novel cell culture system facilitating the generation of stable cultures from patient biopsies- to establish PDX-derived cell lines which maintain the characteristics of the parental PDX tumor. Human lung and ovarian PDX tumors were successfully propagated using CR technology to create stable explant cell lines (CR-PDX). These CR-PDX cell lines maintained parental driver mutations and allele frequency without clonal drift. Purified CR-PDX cell lines were amenable to high throughput chemosensitivity screening and in vitro genetic knockdown studies. Additionally, re-implanted CR-PDX cells proliferated to form tumors that retained the growth kinetics, histology, and drug responses of the parental PDX tumor. CR technology can be used to generate and expand stable cell lines from PDX tumors without compromising fundamental biological properties of the model. It offers the ability to expand PDX cells in vitro for subsequent 2D screening assays as well as for use in vivo to reduce variability, animal usage and study costs. The methods and data detailed here provide a platform to generate physiologically relevant and predictive preclinical models to enhance drug discovery efforts.

Engineering bone tissue substitutes from human induced pluripotent stem cells.

PubMed

de Peppo, Giuseppe Maria; Marcos-Campos, Iván; Kahler, David John; Alsalman, Dana; Shang, Linshan; Vunjak-Novakovic, Gordana; Marolt, Darja

2013-05-21

Congenital defects, trauma, and disease can compromise the integrity and functionality of the skeletal system to the extent requiring implantation of bone grafts. Engineering of viable bone substitutes that can be personalized to meet specific clinical needs represents a promising therapeutic alternative. The aim of our study was to evaluate the utility of human-induced pluripotent stem cells (hiPSCs) for bone tissue engineering. We first induced three hiPSC lines with different tissue and reprogramming backgrounds into the mesenchymal lineages and used a combination of differentiation assays, surface antigen profiling, and global gene expression analysis to identify the lines exhibiting strong osteogenic differentiation potential. We then engineered functional bone substitutes by culturing hiPSC-derived mesenchymal progenitors on osteoconductive scaffolds in perfusion bioreactors and confirmed their phenotype stability in a subcutaneous implantation model for 12 wk. Molecular analysis confirmed that the maturation of bone substitutes in perfusion bioreactors results in global repression of cell proliferation and an increased expression of lineage-specific genes. These results pave the way for growing patient-specific bone substitutes for reconstructive treatments of the skeletal system and for constructing qualified experimental models of development and disease.

Gold Nanoparticle Contrast Agents in Mammography: A Feasibility Study

DTIC Science & Technology

2008-08-01

grid and allowed to dry for 6 hours prior to imaging. The grid was then imaged using a high-resolution transmission electron microscopy, and the...9. Lasfargues EY , Coutinho WG, Redfield ES. Isolation of two human tumor epithelial cell lines from solid breast carcinomas. Journal of National...tissue [14]. These probes have also been used to track immune-stimulating cells implanted into cancer patients for treatment purposes. Targeted contrast

DOE Office of Scientific and Technical Information (OSTI.GOV)

Anna-Liisa Brownell

Adult progenitor cells hold promise for therapeutic treatment where there has been a disabling loss of function due to death of cells from trauma, disease or aging. However, it will be essential in clinical application to be able to follow the fate of the transplanted cells over time using in vivo tracking methods. We have developed protocol for labeling of progenitor cells to monitor cell trafficking by high resolution magnetic resonance imaging (MRI) and super high resolution positron emission tomography (PET). We have transfected rat subventricular zone stem cells (SVZ, progenitor cell line) and another control cell line (PC12, pheochromocytomamore » cells) utilizing super paramagnetic iron oxide and poly-L-lysine complex for MR imaging or radiolabeling with 18F-fluor deoxy-D- glucose for PET imaging. The labeled cells were transplanted into the rostral migratory stream (RMS) or striatum of normal or 6-hydroxydopamine lesioned Spraque-Dawley rats. Longitudinal MRI studies (up to 40 days) showed that transplantation site has significant impact to the fate of the cells; when SVZ cells were transplanted into the RMS, cells migrated several centimeter into the olfactory bulb; after transplantation into the striatum, the migration was minimal, only 2 mm. PC 12 cells grew a massive tumor after the striatal implantation and significantly smaller tumor after the RMS implantation. PET studies conducted immediately after transplantation verified the transplantation site. MRI studies were able to show the whole path of migration in one image, since part of the cells die during migration and will get detected because of iron content. Endpoint histological studies verified the cell survival and immunohistochemical studies revealed the differentiation of the transplanted cells into astrocytes and neurons.« less

The Otto Aufranc Award: enhanced biocompatibility of stainless steel implants by titanium coating and microarc oxidation.

PubMed

Lim, Young Wook; Kwon, Soon Yong; Sun, Doo Hoon; Kim, Yong Sik

2011-02-01

Stainless steel is one of the most widely used biomaterials for internal fixation devices, but is not used in cementless arthroplasty implants because a stable oxide layer essential for biocompatibility cannot be formed on the surface. We applied a Ti electron beam coating, to form oxide layer on the stainless steel surface. To form a thicker oxide layer, we used a microarc oxidation process on the surface of Ti coated stainless steel. Modification of the surface using Ti electron beam coating and microarc oxidation could improve the ability of stainless steel implants to osseointegrate. The ability of cells to adhere to grit-blasted, titanium-coated, microarc-oxidated stainless steel in vitro was compared with that of two different types of surface modifications, machined and titanium-coated, and microarc-oxidated. We performed energy-dispersive x-ray spectroscopy and scanning electron microscopy investigations to assess the chemical composition and structure of the stainless steel surfaces and cell morphology. The biologic responses of an osteoblastlike cell line (SaOS-2) were examined by measuring proliferation (cell proliferation assay), differentiation (alkaline phosphatase activity), and attraction ability (cell migration assay). Cell proliferation, alkaline phosphatase activity, migration, and adhesion were increased in the grit-blasted, titanium-coated, microarc-oxidated group compared to the two other groups. Osteoblastlike cells on the grit-blasted, titanium-coated, microarc-oxidated surface were strongly adhered, and proliferated well compared to those on the other surfaces. The surface modifications we used (grit blasting, titanium coating, microarc oxidation) enhanced the biocompatibility (proliferation and migration of osteoblastlike cells) of stainless steel. This process is not unique to stainless steel; it can be applied to many metals to improve their biocompatibility, thus allowing a broad range of materials to be used for cementless implants.

ZnO nanoparticle incorporated nanostructured metallic titanium for increased mesenchymal stem cell response and antibacterial activity

NASA Astrophysics Data System (ADS)

Elizabeth, Elmy; Baranwal, Gaurav; Krishnan, Amit G.; Menon, Deepthy; Nair, Manitha

2014-03-01

Recent trends in titanium implants are towards the development of nanoscale topographies that mimic the nanoscale properties of bone tissue. Although the nanosurface promotes the integration of osteoblast cells, infection related problems can also occur, leading to implant failure. Therefore it is imperative to reduce bacterial adhesion on an implant surface, either with or without the use of drugs/antibacterial agents. Herein, we have investigated two different aspects of Ti surfaces in inhibiting bacterial adhesion and concurrently promoting mammalian cell adhesion. These include (i) the type of nanoscale topography (Titania nanotube (TNT) and Titania nanoleaf (TNL)) and (ii) the presence of an antibacterial agent like zinc oxide nanoparticles (ZnOnp) on Ti nanosurfaces. To address this, periodically arranged TNT (80-120 nm) and non-periodically arranged TNL surfaces were generated by the anodization and hydrothermal techniques respectively, and incorporated with ZnOnp of different concentrations (375 μM, 750 μM, 1.125 mM and 1.5 mM). Interestingly, TNL surfaces decreased the adherence of staphylococcus aureus while increasing the adhesion and viability of human osteosarcoma MG63 cell line and human mesenchymal stem cells, even in the absence of ZnOnp. In contrast, TNT surfaces exhibited an increased bacterial and mammalian cell adhesion. The influence of ZnOnp on these surfaces in altering the bacterial and cell adhesion was found to be concentration dependent, with an optimal range of 375-750 μM. Above 750 μM, although bacterial adhesion was reduced, cellular viability was considerably affected. Thus our study helps us to infer that nanoscale topography by itself or its combination with an optimal concentration of antibacterial ZnOnp would provide a differential cell behavior and thereby a desirable biological response, facilitating the long term success of an implant.

Maintenance of Epithelial Stem Cells by Cbl Proteins

DTIC Science & Technology

2012-09-01

may be a potential mechanism behind inhibition of MEC differentiation in the absence of Cbl.   7   Figure 1. Flow cytometry analysis of hTERT...results in tumors at the implant site as well as distant metastases To assess whether ErbB2-dependent MPPS1 cells retain their oncogenic potential ...the levels of ErbB2 are not lost in this cell line during culture [ ]. This in itself suggested the potential dependence of oncogenic traits of MPPS1

Controlling transgene expression in subcutaneous implants using a skin lotion containing the apple metabolite phloretin.

PubMed

Gitzinger, Marc; Kemmer, Christian; El-Baba, Marie Daoud; Weber, Wilfried; Fussenegger, Martin

2009-06-30

Adjustable control of therapeutic transgenes in engineered cell implants after transdermal and topical delivery of nontoxic trigger molecules would increase convenience, patient compliance, and elimination of hepatic first-pass effect in future therapies. Pseudomonas putida DOT-T1E has evolved the flavonoid-triggered TtgR operon, which controls expression of a multisubstrate-specific efflux pump (TtgABC) to resist plant-derived defense metabolites in its rhizosphere habitat. Taking advantage of the TtgR operon, we have engineered a hybrid P. putida-mammalian genetic unit responsive to phloretin. This flavonoid is contained in apples, and, as such, or as dietary supplement, regularly consumed by humans. The engineered mammalian phloretin-adjustable control element (PEACE) enabled adjustable and reversible transgene expression in different mammalian cell lines and primary cells. Due to the short half-life of phloretin in culture, PEACE could also be used to program expression of difficult-to-produce protein therapeutics during standard bioreactor operation. When formulated in skin lotions and applied to the skin of mice harboring transgenic cell implants, phloretin was able to fine-tune target genes and adjust heterologous protein levels in the bloodstream of treated mice. PEACE-controlled target gene expression could foster advances in biopharmaceutical manufacturing as well as gene- and cell-based therapies.

Controlling transgene expression in subcutaneous implants using a skin lotion containing the apple metabolite phloretin

PubMed Central

Gitzinger, Marc; Kemmer, Christian; El-Baba, Marie Daoud; Weber, Wilfried; Fussenegger, Martin

2009-01-01

Adjustable control of therapeutic transgenes in engineered cell implants after transdermal and topical delivery of nontoxic trigger molecules would increase convenience, patient compliance, and elimination of hepatic first-pass effect in future therapies. Pseudomonas putida DOT-T1E has evolved the flavonoid-triggered TtgR operon, which controls expression of a multisubstrate-specific efflux pump (TtgABC) to resist plant-derived defense metabolites in its rhizosphere habitat. Taking advantage of the TtgR operon, we have engineered a hybrid P. putida–mammalian genetic unit responsive to phloretin. This flavonoid is contained in apples, and, as such, or as dietary supplement, regularly consumed by humans. The engineered mammalian phloretin-adjustable control element (PEACE) enabled adjustable and reversible transgene expression in different mammalian cell lines and primary cells. Due to the short half-life of phloretin in culture, PEACE could also be used to program expression of difficult-to-produce protein therapeutics during standard bioreactor operation. When formulated in skin lotions and applied to the skin of mice harboring transgenic cell implants, phloretin was able to fine-tune target genes and adjust heterologous protein levels in the bloodstream of treated mice. PEACE-controlled target gene expression could foster advances in biopharmaceutical manufacturing as well as gene- and cell-based therapies. PMID:19549857

Intracapsular implant rupture: MR findings of incomplete shell collapse.

PubMed

Soo, M S; Kornguth, P J; Walsh, R; Elenberger, C; Georgiade, G S; DeLong, D; Spritzer, C E

1997-01-01

The objective of this study was to determine the frequency and significance of the MR findings of incomplete shell collapse for detecting implant rupture in a series of surgically removed breast prostheses. MR images of 86 breast implants in 44 patients were studied retrospectively and correlated with surgical findings at explantation. MR findings included (a) complete shell collapse (linguine sign), 21 implants; (b) incomplete shell collapse (subcapsular line sign, teardrop sign, and keyhole sign), 33 implants; (c) radial folds, 31 implants; and (d) normal, 1 implant. The subcapsular line sign was seen in 26 implants, the teardrop sign was seen in 27 implants, and the keyhole sign was seen in 23 implants. At surgery, 48 implants were found to be ruptured and 38 were intact. The MR findings of ruptured implants showed signs of incomplete collapse in 52% (n = 25), linguine sign in 44% (n = 21), and radial folds in 4% (n = 2). The linguine sign perfectly predicted implant rupture, but sensitivity was low. Findings of incomplete shell collapse improved sensitivity and negative predictive values, and the subcapsular line sign produced a significant incremental increase in predictive ability. MRI signs of incomplete shell collapse were more common than the linguine sign in ruptured implants and are significant contributors to the high sensitivity and negative predictive values of MRI for evaluating implant integrity.

Usefulness of an Osteotomy Template for Skull Tumorectomy and Simultaneous Skull Reconstruction.

PubMed

Oji, Tomito; Sakamoto, Yoshiaki; Miwa, Tomoru; Nakagawa, Yu; Yoshida, Kazunari; Kishi, Kazuo

2016-09-01

Simultaneous tumor resection and cranioplasty with hydroxyapatite osteosynthesis are sometimes necessary in patients of skull neoplasms or skull-invasive tumors. However, the disadvantage of simultaneous surgery is that mismatches often occur between the skull defect and the hydroxyapatite implant. To solve this problem, the authors developed a customized template for designing the craniotomy line. Before each operation, the craniotomy design was discussed with a neurosurgeon. Based on the discussion, 2 hydroxyapatite implants were customized for each patient on the basis of models prepared using computed tomography data. The first implant was an onlay template for the preoperative cranium, which was customized for designing the osteotomy line. The other implant was used for the skull defect. Using the template, the osteotomy line was drawn along the template edge, osteotomy was performed along this line, and the implant was placed in the skull defect. This technique was performed in 3 patients. No implant or defect trimming was required in any patient, good cosmetic outcomes were noted in all patients, and no complications occurred. Use of predesigned hydroxyapatite templates for craniotomy during simultaneous skull tumor resection and cranioplasty has some clinical advantages: the precise craniotomy line can be designed, the implant and skull defect fit better and show effective osteoconduction, trimming of the implant or defect is minimized, and the operation time is shortened.

Unique antitumor property of the Mg-Ca-Sr alloys with addition of Zn

PubMed Central

Wu, Yuanhao; He, Guanping; Zhang, Yu; Liu, Yang; Li, Mei; Wang, Xiaolan; Li, Nan; Li, Kang; Zheng, Guan; Zheng, Yufeng; Yin, Qingshui

2016-01-01

In clinical practice, tumor recurrence and metastasis after orthopedic prosthesis implantation is an intensely troublesome matter. Therefore, to develop implant materials with antitumor property is extremely necessary and meaningful. Magnesium (Mg) alloys possess superb biocompatibility, mechanical property and biodegradability in orthopedic applications. However, whether they possess antitumor property had seldom been reported. In recent years, it showed that zinc (Zn) not only promote the osteogenic activity but also exhibit good antitumor property. In our present study, Zn was selected as an alloying element for the Mg-1Ca-0.5Sr alloy to develop a multifunctional material with antitumor property. We investigated the influence of the Mg-1Ca-0.5Sr-xZn (x = 0, 2, 4, 6 wt%) alloys extracts on the proliferation rate, cell apoptosis, migration and invasion of the U2OS cell line. Our results show that Zn containing Mg alloys extracts inhibit the cell proliferation by alteration the cell cycle and inducing cell apoptosis via the activation of the mitochondria pathway. The cell migration and invasion property were also suppressed by the activation of MAPK (mitogen-activated protein kinase) pathway. Our work suggests that the Mg-1Ca-0.5Sr-6Zn alloy is expected to be a promising orthopedic implant in osteosarcoma limb-salvage surgery for avoiding tumor recurrence and metastasis. PMID:26907515

Micrometer-sized iron oxide particle labeling of mesenchymal stem cells for magnetic resonance imaging-based monitoring of cartilage tissue engineering.

PubMed

Saldanha, Karl J; Doan, Ryan P; Ainslie, Kristy M; Desai, Tejal A; Majumdar, Sharmila

2011-01-01

To examine mesenchymal stem cell (MSC) labeling with micrometer-sized iron oxide particles (MPIOs) for magnetic resonance imaging (MRI)-based tracking and its application to monitoring articular cartilage regeneration. Rabbit MSCs were labeled using commercial MPIOs. In vitro MRI was performed with gradient echo (GRE) and spin echo (SE) sequences at 3T and quantitatively characterized using line profile and region of interest analysis. Ex vivo MRI of hydrogel-encapsulated labeled MSCs implanted within a bovine knee was performed with spoiled GRE (SPGR) and T(1ρ) sequences. Fluorescence microscopy, labeling efficiency, and chondrogenesis of MPIO-labeled cells were also examined. MPIO labeling results in efficient contrast uptake and signal loss that can be visualized and quantitatively characterized via MRI. SPGR imaging of implanted cells results in ex vivo detection within native tissue, and T(1ρ) imaging is unaffected by the presence of labeled cells immediately following implantation. MPIO labeling does not affect quantitative glycosaminoglycan production during chondrogenesis, but iron aggregation hinders extracellular matrix visualization. This aggregation may result from excess unincorporated particles following labeling and is an issue that necessitates further investigation. This study demonstrates the promise of MPIO labeling for monitoring cartilage regeneration and highlights its potential in the development of cell-based tissue engineering strategies. Published by Elsevier Inc.

Cytocompatibility, cytotoxicity and genotoxicity analysis of dental implants

NASA Astrophysics Data System (ADS)

Reigosa, M.; Labarta, V.; Molinari, G.; Bernales, D.

2007-11-01

Several types of materials are frequently used for dental prostheses in dental medicine. Different treatments with titanium are the most used. The aim of the present study was to analyze by means of cytotoxicity and cytocompatibility techniques the capacity of dental implants to integrate to the bone tissue. Cultures of UMR 106 cell line derived from an osteosarcoma were used for bioassays mainly because they show many of the properties of osteoblasts. Dental implant samples provided by B&W company were compared with others of recognized trademarks. The first ones contain ASTM titanium (8348 GR2) with acid printing. Cytotoxicity was analyzed by means of lysosome activity, using the neutral red technique and alkaline phosphatase enzyme activity. Cell variability was determined by means of the acridine ethidium-orange bromide technique. One-way ANOVA and Bonferroni and Duncan post-ANOVA tests were used for the statistical analysis. The assays did not show significant differences among the dental implants analyzed. Our findings show that the dental prostheses studied present high biocompatibility, quantified by the bioassays performed. The techniques employed revealed that they can be a useful tool for the analysis of other materials for dental medicine use.

Hexavalent Chromium Induces Chromosome Instability in Human Urothelial Cells

PubMed Central

Wise, Sandra S.; Holmes, Amie L.; Liou, Louis; Adam, Rosalyn M.; Wise, John Pierce

2016-01-01

Numerous metals are well-known human bladder carcinogens. Despite the significant occupational and public health concern of metals and bladder cancer, the carcinogenic mechanisms remain largely unknown. Chromium, in particular, is a metal of concern as incidences of bladder cancer have been found elevated in chromate workers, and there is an increasing concern for patients with metal hip implants. However, the impact of Cr(VI) on bladder cells has not been studied. We compared chromate toxicity in two bladder cell lines; primary human urothelial cells and hTERT-immortalized human urothelial cells. Hexavalent chromium (Cr(VI)) induced a concentration- and time-dependent increase in chromosome damage in both cell lines, with the hTERT-immortalized cells exhibiting more chromosome damage than the primary cells. Chronic exposure to Cr(VI) also induced a concentration-dependent increase in aneuploid metaphases in both cell lines which was not observed after a 24 h exposure. Aneuploidy induction was higher in the hTERT-immortalized cells. When we correct for uptake, Cr(VI) induces a similar amount of chromosome damage and aneuploidy suggesting that the differences in Cr(VI) sensitivity between the two cells lines were due to differences in uptake. The increase in chromosome instability after chronic chromate treatment suggests this may be a mechanism for chromate-induced bladder cancer specifically and may be a mechanism for metal-induced bladder cancer in general. PMID:26908176

Zr61Ti2Cu25Al12 metallic glass for potential use in dental implants: biocompatibility assessment by in vitro cellular responses.

PubMed

Li, Jing; Shi, Ling-ling; Zhu, Zhen-dong; He, Qiang; Ai, Hong-jun; Xu, Jian

2013-05-01

In comparison with titanium and its alloys, Zr61Ti2Cu25Al12 (ZT1) bulk metallic glass (BMG) manifests a good combination of high strength, high fracture toughness and lower Young's modulus. To examine its biocompatibility required for potential use in dental implants, this BMG was used as a cell growth subtract for three types of cell lines, L929 fibroblasts, human umbilical vein endothelial cells (HUVEC), and osteoblast-like MG63 cells. For a comparison, these cell lines were in parallel cultured and grown also on commercially pure titanium (CP-Ti) and Ti6-Al4-V alloy (Ti64). Cellular responses on the three metals, including adhesion, morphology and viability, were characterized using the SEM visualization and CCK-8 assay. Furthermore, real-time RT-PCR was used to measure the activity of integrin β, alkaline phosphatase (ALP) and type I collagen (COL I) in adherent MG63 cells. As indicated, in all cases of three cell lines, no significant differences in the initial attachment and viability/proliferation were found between ZT1, CP-Ti, and Ti64 until 5d of incubation period. It means that the biocompatibility in cellular response for ZT1 BMG is comparable to Ti and its alloys. For gene expression of integrin β, ALP and COL I, mRNA level from osteoblast cells grown on ZT1 substrates is significantly higher than that on the CP-Ti and Ti64. It suggests that the adhesion and differentiation of osteoblasts grown on ZT1 are even superior to those on the CP-Ti and Ti64 alloy, then promoting bone formation. The good biocompatibility of ZT1 BMG is associated with the formation of zirconium oxide layer on the surface and good corrosion-resistance in physiological environment. Copyright © 2013 Elsevier B.V. All rights reserved.

Functionality and antidiabetic utility of β- and L-cell containing pseudoislets

DOE Office of Scientific and Technical Information (OSTI.GOV)

Green, Alastair D.; Vasu, Srividya, E-mail: s.vasu@ulster.ac.uk; Flatt, Peter R.

Unavailability of tissue and poor engraftment remain significant obstacles to clinical islet transplantation. Here, the therapeutic potential of pseudoislets generated from the insulin and GLP-1 releasing cell-lines MIN6 and GLUTag was investigated. Glucose and other secretagogues evoked 1.3–5.7 fold increases in insulin secretion from both pseudoislet types. Secretion expressed in relation to basal values did not greatly differ between configurations. Exposure of both types of pseudoislets to ninhydrin, H{sub 2}O{sub 2}, streptozotocin or cytokine cocktails decreased viability and increased apoptosis. However, combined pseudoislets exhibited enhanced resistance (1.2–1.7 fold increased LD{sub 50,} 1.2–1.4 fold decreased apoptosis). Implantation of pseudoislets into streptozotocin-diabeticmore » SCID mice precipitated cell masses containing immunoreactive insulin and GLP-1. Implantation of both pseudoislet types was associated with significant reductions in blood glucose, increased plasma insulin, greater bodyweight, decreased polydipsia and improved glucose tolerance. These changes greatly exaggerated in MIN6 pseudoislet recipients, with mice becoming severely hypoglycaemic. In contract, combined pseudoislet recipients achieved tempered restoration of normoglycaemia and exhibited increased plasma GLP-1, decreased plasma and pancreatic glucagon, increased pancreatic insulin and enhancements in islet β:α cells and the ratio of Ki67: TUNEL positive β-cells. MIN6 pseudoislet implantation increased islet β:α cell ratio but did not affect β-cell proliferation or hormone content. Our observations highlight the potential of combining insulin and GLP-1 cell therapy using heterotypic pseudoislets.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kiradzhiyska, D. D., E-mail: denica.kiradjiiska@gmail.com; Mantcheva, R. D., E-mail: r-manch@abv.bg; Feodorova, Y. N.

Materials for medical implants should have suitable mechanical properties, excellent biocompatibility and high corrosion resistance. They should not stimulate allergic and immunologic reactions and should not cause cancer. The use of aluminum as a construction material in implantology is continuously expanding. There are various methods for surface treatment to improve its biocompatibility. In this study aluminum samples anodized in 15% H{sub 2} SO{sub 4} or treated with positive or negative corona discharge were investigated. PDL-cell line of immortalized cells, precursors of periodontal ligament and RAW 264.7 cell line from mouse macrophages are used for the bioassays. The results show thatmore » 10 and 20 μm thick oxide film provides better development of the PLD cells, compared to untreated aluminum. Metal surfaces with 10 μm thick oxide film show the best properties in terms of cells vitality, proliferation and growth. Polymer treated but uncharged samples show good results.« less

Close-field electroporation gene delivery using the cochlear implant electrode array enhances the bionic ear.

PubMed

Pinyon, Jeremy L; Tadros, Sherif F; Froud, Kristina E; Y Wong, Ann C; Tompson, Isabella T; Crawford, Edward N; Ko, Myungseo; Morris, Renée; Klugmann, Matthias; Housley, Gary D

2014-04-23

The cochlear implant is the most successful bionic prosthesis and has transformed the lives of people with profound hearing loss. However, the performance of the "bionic ear" is still largely constrained by the neural interface itself. Current spread inherent to broad monopolar stimulation of the spiral ganglion neuron somata obviates the intrinsic tonotopic mapping of the cochlear nerve. We show in the guinea pig that neurotrophin gene therapy integrated into the cochlear implant improves its performance by stimulating spiral ganglion neurite regeneration. We used the cochlear implant electrode array for novel "close-field" electroporation to transduce mesenchymal cells lining the cochlear perilymphatic canals with a naked complementary DNA gene construct driving expression of brain-derived neurotrophic factor (BDNF) and a green fluorescent protein (GFP) reporter. The focusing of electric fields by particular cochlear implant electrode configurations led to surprisingly efficient gene delivery to adjacent mesenchymal cells. The resulting BDNF expression stimulated regeneration of spiral ganglion neurites, which had atrophied 2 weeks after ototoxic treatment, in a bilateral sensorineural deafness model. In this model, delivery of a control GFP-only vector failed to restore neuron structure, with atrophied neurons indistinguishable from unimplanted cochleae. With BDNF therapy, the regenerated spiral ganglion neurites extended close to the cochlear implant electrodes, with localized ectopic branching. This neural remodeling enabled bipolar stimulation via the cochlear implant array, with low stimulus thresholds and expanded dynamic range of the cochlear nerve, determined via electrically evoked auditory brainstem responses. This development may broadly improve neural interfaces and extend molecular medicine applications.

Physicochemical and osteoplastic characteristics of 3D printed bone grafts based on synthetic calcium phosphates and natural polymers

NASA Astrophysics Data System (ADS)

Nezhurina, E. K.; Karalkin, P. A.; Komlev, V. S.; Sviridova, I. K.; Kirsanova, V. A.; Akhmedova, S. A.; Shanskiy, Ya D.; Fedotov, A. Yu; Barinov, S. M.; Sergeeva, N. S.

2018-04-01

A creation of personalized implants for regeneration of bone tissue seems to be a very promising biomedical technological approach. We have studied the physicochemical characteristics, cyto- and biocompatibility of three-dimensional constructs based on sodium alginate and gelatin in combination with 2 types of calcium phosphate (tricalcium phosphate or octacalcium phosphate) obtained by inkjet 3D printing. In our experiments, we have studied the physical and chemical properties of the constructs – their porosity, chemical composition, microarchitecture of the surface and mechanical elasticity. The cytocompatibility of 3D constructs and matrix-for-cell properties were investigated in vitro on a model of human osteosarcoma MG-63 cell line by means of MTT assay. The biocompatibility of 3D constructs was studied on the model of subcutaneous implantation in mice up to 12 weeks. All types of 3D constructs were cytocompatible in vitro, demonstrated good matrix-for-cells properties, and had supported cell proliferation for 2 weeks. In results of subcutaneous in vivo test all constructs demonstrated biocompatibility with slow bioresorption of organic and inorganic components. Osteogenesis proceeded more actively in rat tibia model defects (marginal excision), substituted by 3D printed 3-component implants based on alginate, gelatin and octacalcium phosphate.

Osteoconductive phosphoserine-modified poly(ε-lysine) dendrons: synthesis, titanium oxide surface functionalization and response of osteoblast-like cell lines

PubMed Central

Meikle, S. T.; Bianchi, G.; Olivier, G.; Santin, M.

2013-01-01

The lack of direct bonding between the surface of an implant and the mineralized bony tissue is among the main causes of aseptic loosening in titanium-based implants. Surface etching and ceramic coatings have led to improved osteointegration, but their clinical performance is still limited either by partial bonding or by coating delamination. In this work, a solid-phase synthesis method has been optimized to produce poly(ε-lysine) dendrons, the outermost branching generation of which is functionalized by phosphoserine (PS), a known catalyst of the biomineralization process. The dendrons were deposited onto etched titanium oxide surfaces as a near-to-monolayer film able to induce the formation of a homogeneous calcium phosphate phase in a simulated body fluid over 3 days. The dendron films also stimulated MG63 and SAOS-2 osteoblast-like cells to proliferate at a rate significantly higher than etched titanium, with SAOS-2 also showing a higher degree of differentiation over 14 days. PS-tethered dendron films were not affected by various sterilization methods and UV treatment appeared to improve the cell substrate potential of these films, thus suggesting their potential as a surface functionalization method for bone implants. PMID:23193106

Expression of the vascular endothelial growth factor receptor neuropilin-1 at the human embryo-maternal interface.

PubMed

Baston-Buest, Dunja M; Porn, Anne C; Schanz, Andrea; Kruessel, Jan-S; Janni, Wolfgang; Hess, Alexandra P

2011-02-01

Angiogenesis is required for successful implantation of the invading blastocyst. Vascular endothelial growth factor (VEGF) is an important key player in angiogenesis and vascular remodeling during the implantation process. Besides its well-characterized receptors VEGFR1 and VEGFR2, neuropilin-1 (NRP-1) has been shown to play an additional role in the signaling process of angiogenesis in human endometrium during the menstrual cycle, as a co-receptor of VEGF. These findings led to the hypothesis that NRP-1 might play a role in the vascular remodeling process during embryo implantation and the establishment of a pregnancy. NRP-1 mRNA transcript and protein expression were investigated in human choriocarcinoma cell lines (JEG-3, Jar and BeWo) aiming to evaluate the expression of NRP-1 in vitro, as well as in human decidua of all three trimesters of pregnancy, by western blot analysis (three samples of each trimester of pregnancy). The localization of NRP-1 in human decidua of all three trimesters of pregnancy was analyzed by immunohistochemistry (five samples of each trimester of pregnancy). NRP-1 transcript and protein were expressed in all cell lines examined. Corresponding to the analysis of human tissue by western blot and the localization by immunohistochemistry, NRP-1 protein higher expressed in samples of early pregnancy in comparison to the end of pregnancy. NRP-1 was expressed in the decidua, villi and invading cytotrophoblast of all samples investigated. This is the first study clearly showing the expression of NRP-1 in human decidua and trophoblast, suggesting an important role for the VEGF co-receptor NRP-1 besides the established receptor VEGFR2 at the embryo-maternal interface during embryonic implantation and placentation. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

Biological and Mechanical Effects of Micro-Nanostructured Titanium Surface on an Osteoblastic Cell Line In vitro and Osteointegration In vivo.

PubMed

Hao, Jingzu; Li, Ying; Li, Baoe; Wang, Xiaolin; Li, Haipeng; Liu, Shimin; Liang, Chunyong; Wang, Hongshui

2017-09-01

Hybrid micro-nanostructure implant surface was produced on titanium (Ti) surface by acid etching and anodic oxidation to improve the biological and mechanical properties. The biological properties of the micro-nanostructure were investigated by simulated body fluid (SBF) soaking test and MC3T3-E1 cell co-culture experiment. The cell proliferation, spreading, and bone sialoprotein (BSP) gene expression were examined by MTT, SEM, and reverse transcription-polymerase chain reaction (RT-PCR), respectively. In addition, the mechanical properties were evaluated by instrumented nanoindentation test and friction-wear test. Furthermore, the effect of the micro-nanostructure surface on implant osteointegration was examined by in vivo experiment. The results showed that the formation of bone-like apatite was accelerated on the micro-nanostructured Ti surface after immersion in simulated body fluid, and the proliferation, spreading, and BSP gene expression of the MC3T3-E1 cells were also upregulated on the modified surface. The micro-nanostructured Ti surface displayed decreased friction coefficient, stiffness value, and Young's modulus which were much closer to those of the cortical bone, compared to the polished Ti surface. This suggested much better mechanical match to the surrounding bone tissue of the micro-nanostructured Ti surface. Furthermore, the in vivo animal experiment showed that after implantation in the rat femora, the micro-nanostructure surface displayed higher bonding strength between bone tissues and implant; hematoxylin and eosin (H&E) staining suggested that much compact osteoid tissue was observed at the interface of Micro-nano-Ti-bone than polished Ti-bone interface after implantation. Based on these results mentioned above, it was concluded that the improved biological and mechanical properties of the micro-nanostructure endowed Ti surface with good biocompatibility and better osteointegration, implying the enlarged application of the micro-nanostructure surface Ti implants in future.

Reduced tumorigenicity of rat glioma cells in the brain when mediated by hygromycin phosphotransferase.

PubMed

Hormigo, A; Friedlander, D R; Brittis, P A; Zagzag, D; Grumet, M

2001-04-01

A variant of C6 glioma cells, C6R-G/H cells express hygromycin phosphotransferase (HPT) and appear to have reduced tumorigenicity in the embryonic brain. The goal of this study was to investigate their reduced capacity to generate tumors in the adult rat brain. Cell lines were implanted into rat brains and tumorigenesis was evaluated. After 3 weeks, all rats with C6 cells showed signs of neurological disease, whereas rats with C6R-G/H cells did not and were either killed then or allowed to survive until later. Histological studies were performed to analyze tumor size, malignancy, angiogenesis, and cell proliferation. Cells isolated from rat brain tumors were analyzed for mutation to HPT by testing their sensitivity to hygromycin. The results indicate that HPT suppresses tumor formation. Three weeks after implantation, only 44% of animals implanted with C6R-G/H cells developed tumors, whereas all animals that received C6 glioma cells developed high-grade gliomas. The C6R-G/H cells filled a 20-fold smaller maximal cross-sectional area than the C6 cells, and exhibited less malignant characteristics, including reduced angiogenesis, mitosis, and cell proliferation. Similar results were obtained in the brain of nude rats, indicating that the immune system did not play a significant role in suppressing tumor growth. The combination of green fluorescent protein (GFP) and HPT was more effective in suppressing tumorigenesis than either plasmid by itself, indicating that the GFP may protect against inactivation of the HPT. Interestingly. hygromycin resistance was lost in tumor cells that were recovered from a group of animals in which C6R-G/H cells formed tumors, confirming the correlation of HPT with reduced tumorigenicity.

[Biocompatibility research of true bone ceramics].

PubMed

Qiao, Wei; Ren, Xiaoqi; Shi, Hao; Li, Jing; Yang, Ting; Ma, Shaoying; Zhao, Yaping; Su, Chengzhong; Li, Baoxing

2017-10-01

To investigate the biocompatibility of true bone ceramic (TBC) and provide experimental basis for clinic application. TBC was prepared from healthy adult bovine cancellous bone by deproteinization and high temperature calcinations. Mouse fibroblast cell line (L929 cells) were cultured with the leaching liquor of TBC in vitro , and the cytotoxicity was evaluated at 2nd, 4th, and 7th days. L929 cells were inoculated into the TBC and cultured for 4 days. The cell adhesion and proliferation on the surface of the TBC were observed by scanning electron microscopy, and evaluated the cell compatibility of TBC. Ten New Zealand white rabbits were divided into 2 groups, and drilled holes at the tibia of both hind limbs. TBC and hydroxyapatite (HA) were implanted into the left side (experimental group) and the right side (control group), respectively. And the biocompatibility of TBC was evaluated by general observation and histological observation at 4 and 26 weeks after implantation. Cytotoxicity test showed that the cytotoxicity level of leaching liquor of TBC was grade 0-1. Cell compatibility experiments showed that the L929 cells adhered well on the surface of TBC and migrated into the pores. The implantation test in vivo showed that experimental group and control group both had mild or moderate inflammatory response at 4 weeks, and new bone formation occurred. At 26 weeks, there was no inflammatory reaction observed in both groups, and new bone formation was observed in varying degrees. TBC have good biocompatibility and can be used to repair bone defect in clinic.

Application of Ti6Al7Nb Alloy for the Manufacture of Biomechanical Functional Structures (BFS) for Custom-Made Bone Implants.

PubMed

Szymczyk, Patrycja; Ziółkowski, Grzegorz; Junka, Adam; Chlebus, Edward

2018-06-08

Unlike conventional manufacturing techniques, additive manufacturing (AM) can form objects of complex shape and geometry in an almost unrestricted manner. AM’s advantages include higher control of local process parameters and a possibility to use two or more various materials during manufacture. In this work, we applied one of AM technologies, selective laser melting, using Ti6Al7Nb alloy to produce biomedical functional structures (BFS) in the form of bone implants. Five types of BFS structures (A1, A2, A3, B, C) were manufactured for the research. The aim of this study was to investigate such technological aspects as architecture, manufacturing methods, process parameters, surface modification, and to compare them with such functional properties such as accuracy, mechanical, and biological in manufactured implants. Initial in vitro studies were performed using osteoblast cell line hFOB 1.19 (ATCC CRL-11372) (American Type Culture Collection). The results of the presented study confirm high applicative potential of AM to produce bone implants of high accuracy and geometric complexity, displaying desired mechanical properties. The experimental tests, as well as geometrical accuracy analysis, showed that the square shaped (A3) BFS structures were characterized by the lowest deviation range and smallestanisotropy of mechanical properties. Moreover, cell culture experiments performed in this study proved that the designed and obtained implant’s internal porosity (A3) enhances the growth of bone cells (osteoblasts) and can obtain predesigned biomechanical characteristics comparable to those of the bone tissue.

Low-cost plasma immersion ion implantation doping for Interdigitated back passivated contact (IBPC) solar cells

DOE PAGES

Young, David L.; Nemeth, William; LaSalvia, Vincenzo; ...

2016-06-01

Here, we present progress to develop low-cost interdigitated back contact solar cells with pc-Si/SiO 2/c-Si passivated contacts formed by plasma immersion ion implantation (PIII). PIII is a lower-cost implantation technique than traditional beam line implantation due to its simpler design, lower operating costs, and ability to run high doses (1E14-1E18 cm -2) at low ion energies (20 eV-10 keV). These benefits make PIII ideal for high throughput production of patterned passivated contacts, where high-dose, low-energy implantations are made into thin (20-200 nm) a-Si layers instead of into the wafer itself. For this work symmetric passivated contact test structures (~100 nmmore » thick) grown on n-Cz wafers with pH3 PIII doping gave implied open circuit voltage (iV oc) values of 730 mV with J o values of 2 fA/cm 2. Samples doped with B 2H 6 gave iV oc values of 690 mV and J o values of 24 fA/cm 2, outperforming BF 3 doping, which gave iV oc values in the 660-680 mV range. Samples were further characterized by SIMS, photoluminescence, TEM, EELS, and post-metallization TLM to reveal micro- and macro-scopic structural, chemical and electrical information.« less

Surface functionalization of TiO2 nanotubes with minocycline and its in vitro biological effects on Schwann cells.

PubMed

A, Lan; Xu, Wenzhou; Zhao, Jinghui; Li, Chunyan; Qi, Manlin; Li, Xue; Wang, Lin; Zhou, Yanmin

2018-06-20

Minocycline has been widely used in central nervous system disease. However, the effect of minocycline on the repairing of nerve fibers around dental implants had not been previously investigated. The aim of the present study was to evaluate the possibility of using minocycline for the repairing of nerve fibers around dental implants by investigating the effect of minocycline on the proliferation of Schwann cells and secretion of neurotrophic factors nerve growth factor and glial cell line-derived neurotrophic factor in vitro. TiO 2 nanotubes were fabricated on the surface of pure titanium via anodization at the voltage of 20, 30, 40 and 50 V. The nanotubes structure were characterized by scanning electron microscopy and examined with an optical contact angle. Then drug loading capability and release behavior were detected in vitro. The TiO 2 nanotubes loaded with different concentration of minocycline were used to produce conditioned media with which to treat the Schwann cells. A cell counting kit-8 assay and cell viability were both selected to study the proliferative effect of the specimens on Schwann cell. Reverse transcription-quantitative PCR and western blot analyses were used to detect the related gene/protein expression of Schwann cells. The results showed that the diameter of TiO 2 nanotubes at different voltage varied from 100 to 200 nm. The results of optical contact angle and releasing profile showed the nanotubes fabricated at the voltage of 30 V met the needs of the carrier of minocycline. In addition, the TiO 2 nanotubes loaded with the concentration of 20 μg/mL minocycline increased Schwann cells proliferation and secretion of neurotrophic factors in vitro. The results suggested that the surface functionalization of TiO 2 nanotubes with minocycline was a promising candidate biomaterial for the peripheral nerve regeneration around dental implants and has potential to be applied in improving the osseoperception of dental implant.

An immortalized steroidogenic goat granulosa cell line as a model system to study the effect of the endoplasmic reticulum (ER)-stress response on steroidogenesis.

PubMed

Yang, Diqi; Wang, Lei; Lin, Pengfei; Jiang, Tingting; Wang, Nan; Zhao, Fan; Chen, Huatao; Tang, Keqiong; Zhou, Dong; Wang, Aihua; Jin, Yaping

2017-02-16

With granulosa and theca cells, the ovaries are responsible for producing oocytes and secreting sex steroids such as estrogen and progesterone. Endoplasmic reticulum stress (ERS) plays an important role in follicle atresia and embryo implantation. In this study, goat granulosa cells were isolated from medium-sized (4-6 mm) healthy follicles. Primary granulosa cells were immortalized by transfection with human telomerase reverse transcriptase (hTERT) to establish a goat granulosa cell line (hTERT-GGCs). These hTERT-GGCs expressed hTERT and had relatively long telomeres at passage 50. Furthermore, hTERT-GGCs expressed the gonadotropin receptor genes CYP11A1, StAR, and CYP19A1, which are involved in steroidogenesis. Additionally, progesterone was detectable in hTERT-GGCs. Although the proliferation potential of hTERT-GGCs significantly improved, there was no evidence to suggest that the hTERT-GGCs are tumorigenic. In addition, thapsigargin (Tg) treatment led to a significant dose-dependent decrease in progesterone concentration and steroidogenic enzyme expression. In summary, we successfully generated a stable goat granulosa cell line. We found that Tg induced ERS in hTERT-GGCs, which reduced progesterone production and steroidogenic enzyme expression. Future studies may benefit from using this cell line as a model to explore the molecular mechanisms regulating steroidogenesis and apoptosis in goat granulosa cells.

Human chorionic gonadotropin triggers angiogenesis via the modulation of endometrial stromal cell responsiveness to interleukin 1: a new possible mechanism underlying embryo implantation.

PubMed

Bourdiec, Amélie; Shao, Rong; Rao, C V; Akoum, Ali

2012-09-01

Deep functional changes occurring within the endometrium during implantation are orchestrated by embryonic and maternal signals. Human chorionic gonadotropin (hCG), a major embryonic signal, plays a critical role in the initiation and maintenance of pregnancy. Interleukin (IL) 1, one of the earliest embryonic signals, appears to exert a direct impact on the receptive endometrium and to induce major molecular changes that are essential for embryo implantation. Herein we investigate whether hCG can modulate endometrial stromal cell (ESC) receptivity to IL1 during the implantation window and assess the impact on angiogenesis in vitro. Primary cultures of ESCs from normal fertile women during the implantation window were treated for 24 h with different concentrations of hCG (0-100 ng/ml) and stimulated for 24 h with IL1B (0-0.1 ng/ml). IL1 receptors (IL1Rs), IL1R antagonist (IL1RA), and monocyte chemotactic protein (MCP) 1 were analyzed by real-time PCR, ELISA, and Western blotting. The angiogenic activity in vitro was studied using human microvascular endothelial cell line, scratch wound assay, and cell proliferation via BrdU incorporation into DNA. Human CG induced a dose-dependent imbalance in ESC receptivity to IL1 by significantly upregulating the functional signaling IL1R1 and concomitantly downregulating the decoy inhibitory IL1R2 and IL1RA upon subsequent exposure to IL1B. Prior exposure to hCG amplified MCP1 secretion by ESCs in response to IL1B and triggered the release of angiogenic activity in vitro in which MCP1 appeared to play a significant role. Overexpression of IL1R2 using cell transfection inhibited IL1 and hCG/IL1B-mediated MCP1 secretion. These findings suggest that hCG coordinates embryonic signal interaction with the maternal endometrium, and point to a new possible pathway by which it may promote embryonic growth.

Obesity associated advanced glycation end products within the human uterine cavity adversely impact endometrial function and embryo implantation competence.

PubMed

Antoniotti, Gabriella S; Coughlan, Melinda; Salamonsen, Lois A; Evans, Jemma

2018-04-01

Do obese levels of advanced glycation end products (AGEs) within the uterine cavity detrimentally alter tissue function in embryo implantation and placental development? Obese levels of AGEs activate inflammatory signaling (p65 NFκB) within endometrial epithelial cells and alter their function, cause endoplasmic reticulum (ER) stress in endometrial stromal cells and impair decidualization, compromise implantation of blastocyst mimics and inhibit trophoblast invasion. Obese women experience a higher incidence of infertility, recurrent miscarriage and pregnancy complications compared with lean women. Oocyte donation cycles suggest a detrimental uterine environment plays a role in these outcomes. Uterine lavage and tissues from lean (BMI 19.5-24.9, n = 17) and obese (BMI > 30, n = 16) women examined. Cell culture experiments utilizing human endometrial epithelial, trophectoderm and trophoblast cell lines and primary human stromal cells used to examine the functional impact of obese levels of AGEs. Levels of AGEs examined within uterine lavage assessed by ELISA to determine differences between lean and obese women. Expression and localization of AGEs, receptor for AGEs (RAGE) and NFκB within endometrial tissues obtained from lean and obese women determined by immunohistochemistry. Endometrial epithelial cells (ECC-1), primary human stromal cells and trophoblast cells (HTR8-SVneo) treated with lean (2000 nmol/mol lysine) or obese (8000 nmol/mol lysine) uterine levels of AGEs and p65 NFκB (western immunoblot), real-time adhesion, proliferation migration and invasion (xCelligence real-time cell function analysis), decidualization (cell morphology and prolactin release), ER stress (western immunoblot for p-PERK) determined. Co-cultures of endometrial epithelial cells and blastocyst mimics (trophectoderm spheroids) similarly treated with lean or obese uterine levels of AGEs to determine their impact on embryo implantation. AGEs were significantly elevated (P = 0.004) within the obese (6503.59 μmol/mol lysine) versus lean (2165.88 μmol/mol lysine) uterine cavity (uterine lavage) with increased immunostaining for AGEs, RAGE and NFkB within obese endometrial tissues during the proliferative phase of the menstrual cycle. Obese uterine levels of AGEs inhibited adhesion and proliferation of endometrial epithelial (ECC-1) cells compared to treatment with lean uterine levels of AGEs. Obese uterine AGE levels impacted primary human endometrial stromal cell decidualization and activated ER stress within these cells. Obese uterine levels of AGEs also inhibited trophectodermal spheroid adhesion to hormonally primed endometrial epithelial cells and trophoblast cell line HTR8/SV-neo invasion. N/A. Mechanistic studies are performed in vitro and may not completely recapitulate cell function in vivo. These data corroborate clinical data suggesting the presence of an altered uterine environment in obese women and demonstrate that elevated uterine levels of AGEs within these women may detrimentally impact endometrial function, embryo implantation and placental development. Uterine AGE assessment in infertility work up may prove useful in determining underlying causes of infertility. AGEs can be targeted pharmacologically and such treatments may prove effective in improving reproductive complications experience by obese women. Supported by NHMRC Fellowship (#1002028 to L.A.S.), and the Victorian Government's Operational Infrastructure Support Program. MTC is supported by a JDRF Australia Clinical Research Network Career Development Award. The authors have declared that no conflict of interest exists.

Bone regeneration: in vitro evaluation of the behaviour of osteoblast-like MG63 cells placed in contact with polylactic-co-glycolic acid, deproteinized bovine bone and demineralized freeze-dried bone allograft.

PubMed

Pappalardo, S; Mastrangelo, F; Reale Marroccia, D; Cappello, V; Ciampoli, C; Carlino, V; Tanteri, L; Costanzo, M; Sinatra, F; Tetè, S

2008-01-01

Insufficient bone density of the alveolar crests, caused by loss of the dental elements, sometimes impedes the primary stability of an integrated bone implant. The techniques of bone regeneration allow to obtain a sufficient quantity of alveolar bone to permit the implant rehabilitation of the edentulous crests. Today several grafting materials are available and they have different characteristics, according to their structure, which influence the different behaviour of the grafting materials to the bone and the implant surface. The aim of this study is to evaluate the interaction between a human osteosarcoma MG63 cell line and three different biomaterials: polylactic-co-glycolic acid (PLAGA), deproteinized bovine bone and demineralised freeze-dried bone allograft (DFDBA). From this study a different behaviour emerges of the osteoblast-like MG63 cells in relation to the sublayer on which these cells were placed in culture. The results of the study, in fact, demonstrate that the most osteoconductive material of the three analysed is the DFDBA, followed by DPBB. On the contrary, the PLGA, because of its roughness, does not seem to represent a valid support for cell growth, and does not encourage any morphologic modification in tumor cells. Furthermore, deproteinized bovine bone shows a differentiating effect which could lead to hypothesise an osteoconductive capacity of this biomaterial. Further studies should be carried out with the aim of explaining the results obtained.

Establishment and genetic characterization of ANGM-CSS, a novel, immortal cell line derived from a human glioblastoma multiforme.

PubMed

Notarangelo, Angelantonio; Trombetta, Domenico; D'Angelo, Vincenzo; Parrella, Paola; Palumbo, Orazio; Storlazzi, Clelia Tiziana; Impera, Luciana; Muscarella, Lucia Anna; La Torre, Antonella; Affuso, Andrea; Fazio, Vito Michele; Carella, Massimo; Zelante, Leopoldo

2014-03-01

Glioblastoma multiforme (World Health Organization, grade IV astrocytoma) is the most common and most aggressive malignant primary brain tumor. We report a novel cell line, designated as ANGM-CSS, which was established from a 56-year-old male patient with a surgically removed glioblastoma multiforme. The ANGM-CSS cell line was established in vitro and characterized using histological and immunohistochemical staining, classical and molecular cytogenetic analyses, molecular studies and functional assays using a xenograft model in immunodeficient animals. ANGM-CSS was positive for CD133, nestin and vimentin proteins, whereas GFAP showed staining only in a fraction of the cells. Cytogenetic and molecular cytogenetic analysis revealed a near-tetraploid karyotype, with a modal chromosome number from 88 to 91, and additional cytogenetic abnormalities, such as the t(6;14)(p12;q11.2), t(8;10)(q24.2;q21.1) and t(5;9)(q34;p21) unbalanced translocations. Moreover, ANGM-CSS showed amplification of the MET and EGFR genes whose overexpression was observed at the mRNA level. Interestingly, ANGM-CSS is tumorigenic when implanted in immunodeficient mice, and the cells obtained from the xenografts showed the same morphology and karyotype in vitro as the original cell line. ANGM-CSS represents a biologically relevant cell line to be used to investigate the molecular pathology of glioblastoma multiforme, also to evaluate the efficacy of novel therapeutic drugs in vitro.

Dasatinib and Doxorubicin Treatment of Sarcoma Initiating Cells: A Possible New Treatment Strategy.

PubMed

Aggerholm-Pedersen, Ninna; Demuth, Christina; Safwat, Akmal; Meldgaard, Peter; Kassem, Moustapha; Sandahl Sorensen, Boe

2016-01-01

Background. One of the major challenges affecting sarcoma treatment outcome, particularly that of metastatic disease, is resistance to chemotherapy. Cancer-initiating cells are considered a major contributor to this resistance. Methods. An immortalised nontransformed human stromal (mesenchymal) stem cell line hMSC-TERT4 and a transformed cell line hMSC-TERT20-CE8, known to form sarcoma-like tumours when implanted in immune-deficient mice, were used as models. Receptor tyrosine kinase (RTK) activation was analysed by RTK arrays and cellular viability after tyrosine kinases inhibitor (TKI) treatment with or without doxorubicin was assessed by MTS assay. Results. Initial results showed that the hMSC-TERT4 was more doxorubicin-sensitive while hMSC-TERT20-CE8 was less doxorubicin-sensitive evidenced by monitoring cell viability in the presence of doxorubicin at different doses. The epidermal growth factor receptor (EGFR) was activated in both cell lines. However hMSC-TERT20-CE8 exhibited significantly higher expression of the EGFR ligands. EGFR inhibitors such as erlotinib and afatinib alone or in combination with doxorubicin failed to further decrease cell viability of hMSC-TERT20-CE8. However, inhibition with the TKI dasatinib in combination with doxorubicin decreased cell viability of the hMSC-TERT20-CE8 cell line. Conclusion. Our results demonstrate that dasatinib, but not EGFR-directed treatment, can decrease cell viability of stromal cancer stem cells less sensitive to doxorubicin.

Investigations of (99m)Tc-labeled glucarate as a SPECT radiotracer for non-small cell lung cancer (NSCLC) and potential tumor uptake mechanism.

PubMed

Meng, Lanfang; Xiu, Yan; Li, Yanli; Xu, Xiaobo; Li, Shanqun; Li, Xiao; Pak, Koon Y; Shi, Hongcheng; Cheng, Dengfeng

2015-07-01

This study attempted to evaluate the feasibility of (99m)Tc-labeled glucarate ((99m)Tc-GLA) imaging in non-small cell lung cancer (NSCLC) and the potential tumor uptake mechanism. Cell lysates from two NSCLC cell lines, H292 and H1975, were immunoblotted with anti-glucose transporter 5 (GLUT5) antibody for Western blotting. Thereafter, the two cell lines were used to examine cellular uptake of (99m)Tc-GLA with or without fructose. SPECT/CT imaging studies were performed on small animals bearing H292 and H1975 tumors. Biodistribution studies were also conducted to achieve accurate tissue uptake of this tracer in two tumor models. Hematoxylin & eosin (H&E) staining and GLUT5, Ki67 and cytokeratin-7 (CK-7) immunohistochemistry (IHC) analysis were further investigated on tumor tissues. In Western blotting, H292 cells showed higher levels of GLUT5 compared to the H1975 cells. Meanwhile, the in vitro cell assays indicated GLUT5-dependent uptake of (99m)Tc-GLA in H292 and H1975 cells. The fructose competition assays showed a significant decrease in (99m)Tc-GLA uptake by H292 and H1975 cells when fructose was added. The (99m)Tc-GLA accumulation was as much as two-fold higher in H292 implanted tumors than in H1975 implanted tumors. (99m)Tc-GLA exhibited rapid clearance pharmacokinetics and reasonable uptake in human NSCLC H292 (1.69±0.37 ID%/g) and H1975 (0.89±0.06 ID%/g) implanted tumors at 30min post injection. Finally, the expression of GLUT5, Ki67 and CK-7 on tumor tissues also exhibited positive correlation with the in vitro cell test results and in vivo SPECT/CT imaging results in xenograft tumors. Both in vitro and ex vivo studies demonstrated that the uptake of (99m)Tc-GLA in NSCLC is highly related to GLUT5 expression. Imaging and further IHC results support that (99m)Tc-GLA could be a promising SPECT imaging agent for NSCLC diagnosis and prognosis evaluation. Copyright © 2015 Elsevier Inc. All rights reserved.

Immobilization of Ag nanoparticles/FGF-2 on a modified titanium implant surface and improved human gingival fibroblasts behavior.

PubMed

Ma, Qianli; Mei, Shenglin; Ji, Kun; Zhang, Yumei; Chu, Paul K

2011-08-01

The objective of this study was to form a rapid and firm soft tissue sealing around dental implants that resists bacterial invasion. We present a novel approach to modify Ti surface by immobilizing Ag nanoparticles/FGF-2 compound bioactive factors onto a titania nanotubular surface. The titanium samples were anodized to form vertically organized TiO(2) nanotube arrays and Ag nanoparticles were electrodeposited onto the nanotubular surface, on which FGF-2 was immobilized with repeated lyophilization. A uniform distribution of Ag nanoparticles/FGF-2 was observed on the TiO(2) nanotubular surface. The L929 cell line was used for cytotoxicity assessment. Human gingival fibroblasts (HGFs) were cultured on the modified surface for cytocompatibility determination. The Ag/FGF-2 immobilized samples displayed excellent cytocompatibility, negligible cytotoxicity, and enhanced HGF functions such as cell attachment, proliferation, and ECM-related gene expression. The Ag nanoparticles also exhibit some bioactivity. In conclusion, this modified TiO(2) nanotubular surface has a large potential for use in dental implant abutment. Copyright © 2011 Wiley Periodicals, Inc.

The Otto Aufranc Award: Enhanced Biocompatibility of Stainless Steel Implants by Titanium Coating and Microarc Oxidation

PubMed Central

Lim, Young Wook; Kwon, Soon Yong; Sun, Doo Hoon

2010-01-01

Background Stainless steel is one of the most widely used biomaterials for internal fixation devices, but is not used in cementless arthroplasty implants because a stable oxide layer essential for biocompatibility cannot be formed on the surface. We applied a Ti electron beam coating, to form oxide layer on the stainless steel surface. To form a thicker oxide layer, we used a microarc oxidation process on the surface of Ti coated stainless steel. Modification of the surface using Ti electron beam coating and microarc oxidation could improve the ability of stainless steel implants to osseointegrate. Questions/purposes The ability of cells to adhere to grit-blasted, titanium-coated, microarc-oxidated stainless steel in vitro was compared with that of two different types of surface modifications, machined and titanium-coated, and microarc-oxidated. Methods We performed energy-dispersive x-ray spectroscopy and scanning electron microscopy investigations to assess the chemical composition and structure of the stainless steel surfaces and cell morphology. The biologic responses of an osteoblastlike cell line (SaOS-2) were examined by measuring proliferation (cell proliferation assay), differentiation (alkaline phosphatase activity), and attraction ability (cell migration assay). Results Cell proliferation, alkaline phosphatase activity, migration, and adhesion were increased in the grit-blasted, titanium-coated, microarc-oxidated group compared to the two other groups. Osteoblastlike cells on the grit-blasted, titanium-coated, microarc-oxidated surface were strongly adhered, and proliferated well compared to those on the other surfaces. Conclusions The surface modifications we used (grit blasting, titanium coating, microarc oxidation) enhanced the biocompatibility (proliferation and migration of osteoblastlike cells) of stainless steel. Clinical Relevance This process is not unique to stainless steel; it can be applied to many metals to improve their biocompatibility, thus allowing a broad range of materials to be used for cementless implants. PMID:20936386

Control of Human Endometrial Stromal Cell Motility by PDGF-BB, HB-EGF and Trophoblast-Secreted Factors

PubMed Central

Schwenke, Maren; Knöfler, Martin; Velicky, Philipp; Weimar, Charlotte H. E.; Kruse, Michelle; Samalecos, Annemarie; Wolf, Anja; Macklon, Nick S.; Bamberger, Ana-Maria; Gellersen, Birgit

2013-01-01

Human implantation involves extensive tissue remodeling at the fetal-maternal interface. It is becoming increasingly evident that not only trophoblast, but also decidualizing endometrial stromal cells are inherently motile and invasive, and likely contribute to the highly dynamic processes at the implantation site. The present study was undertaken to further characterize the mechanisms involved in the regulation of endometrial stromal cell motility and to identify trophoblast-derived factors that modulate migration. Among local growth factors known to be present at the time of implantation, heparin-binding epidermal growth factor-like growth factor (HB-EGF) triggered chemotaxis (directed locomotion), whereas platelet-derived growth factor (PDGF)-BB elicited both chemotaxis and chemokinesis (non-directed locomotion) of endometrial stromal cells. Supernatants of the trophoblast cell line AC-1M88 and of first trimester villous explant cultures stimulated chemotaxis but not chemokinesis. Proteome profiling for cytokines and angiogenesis factors revealed neither PDGF-BB nor HB-EGF in conditioned media from trophoblast cells or villous explants, while placental growth factor, vascular endothelial growth factor and PDGF-AA were identified as prominent secretory products. Among these, only PDGF-AA triggered endometrial stromal cell chemotaxis. Neutralization of PDGF-AA in trophoblast conditioned media, however, did not diminish chemoattractant activity, suggesting the presence of additional trophoblast-derived chemotactic factors. Pathway inhibitor studies revealed ERK1/2, PI3 kinase/Akt and p38 signaling as relevant for chemotactic motility, whereas chemokinesis depended primarily on PI3 kinase/Akt activation. Both chemotaxis and chemokinesis were stimulated upon inhibition of Rho-associated, coiled-coil containing protein kinase. The chemotactic response to trophoblast secretions was not blunted by inhibition of isolated signaling cascades, indicating activation of overlapping pathways in trophoblast-endometrial communication. In conclusion, trophoblast signals attract endometrial stromal cells, while PDGF-BB and HB-EGF, although not identified as trophoblast-derived, are local growth factors that may serve to fine-tune directed and non-directed migration at the implantation site. PMID:23349855

Cellular Therapy With Human Autologous Adipose-Derived Adult Stem Cells for Advanced Keratoconus.

PubMed

Alió Del Barrio, Jorge L; El Zarif, Mona; de Miguel, María P; Azaar, Albert; Makdissy, Norman; Harb, Walid; El Achkar, Ibrahim; Arnalich-Montiel, Francisco; Alió, Jorge L

2017-08-01

The aim of this phase 1 study was to preliminarily evaluate the safety and efficacy of autologous adipose-derived adult stem cell (ADASC) implantation within the corneal stroma of patients with advanced keratoconus. Five consecutive patients were selected. Autologous ADASCs were obtained by elective liposuction. ADASCs (3 × 10) contained in 1 mL saline were injected into the corneal stroma through a femtosecond-assisted 9.5-mm diameter lamellar pocket under topical anesthesia. Patients were reviewed at 1 day, 1 week, 1, 3, and 6 months postoperatively. Visual function, manifest refraction, slit-lamp biomicroscopy, intraocular pressure, endothelial cell density, corneal topography, corneal optical coherence tomography, and corneal confocal biomicroscopy were recorded. No intraoperative or postoperative complications were recorded, with full corneal transparency recovery within 24 hours. Four patients completed the full follow-up. All patients improved their visual function (mean: 1 line of unaided and spectacle-corrected distance vision and 2 lines of rigid contact lens distance vision). Manifest refraction and topographic keratometry remained stable. Corneal optical coherence tomography showed a mean improvement of 16.5 μm in the central corneal thickness, and new collagen production was observed as patchy hyperreflective areas at the level of the stromal pocket. Confocal biomicroscopy confirmed the survival of the implanted stem cells at the surgical plane. Intraocular pressure and endothelial cell density remained stable. Cellular therapy of the human corneal stroma in vivo with autologous ADASCs appears to be safe. Stem cells survive in vivo with intrastromal new collagen production. Future studies with larger samples are required to confirm these preliminary results.

Assessment of different 3D culture systems to study tumor phenotype and chemosensitivity in pancreatic ductal adenocarcinoma.

PubMed

Zeeberg, Katrine; Cardone, Rosa Angela; Greco, Maria Raffaella; Saccomano, Mara; Nøhr-Nielsen, Asbjørn; Alves, Frauke; Pedersen, Stine Falsig; Reshkin, Stephan Joel

2016-07-01

Pancreatic ductal adenocarcinoma (PDAC) is a highly malignant disease with a very poor prognosis, due to the influence of the tumor stroma, which promotes tumor growth, early invasion and chemoradiation resistance. Efforts to develop models for identifying novel anticancer therapeutic compounds have been hampered by the limited ability of in vitro models to mimic these in vivo tumor-stroma interactions. This has led to the development of various three-dimensional (3D) culture platforms recapitulating the in vivo tumor-stroma crosstalk and designed to better understand basic cancer processes and screen drug action. However, a consensus for different experimental 3D platforms is still missing in PDAC. We compared four PDAC cell lines of different malignancy grown in 2D monolayers to three of the more commonly used 3D techniques (ultralow adhesion concave microwells, Matrigel inclusion and organotypic systems) and to tumors derived from their orthotopic implantation in mice. In these 3D platforms, we observed that cells grow with very different tumor morphologies and the organotypic setting most closely resembles the tumor cytoarchitecture obtained by orthotopically implanting the four cell lines in mice. We then analyzed the molecular and cellular responses of one of these cell lines to epidermal growth factor receptor (EGFR) stimulation with EGF and inhibition with erlotinib and found that only in the 3D platforms, and especially the organotypic, cells: i) responded to EGF by changing the expression of signalling components underlying cell-stroma crosstalk and tissue architecture, growth, invasion and drug resistance (E-cadherin, EGFR, ezrin, β1 integrin, NHERF1 and HIF-1α) similar to those reported in vivo; ii) had stimulated growth and increased erlotinib sensitivity in response to EGF, more faithfully mimicking their known in vivo behaviour. Altogether, these results, indicate the organotypic as the most relevant physiological 3D system to study the complex tumor stroma interactions driving progression and determining chemio-resistance.

Mechanical behavior of the human lumbar intervertebral disc with polymeric hydrogel nucleus implant: An experimental and finite element study

NASA Astrophysics Data System (ADS)

Joshi, Abhijeet Bhaskar

The origin of the lower back pain is often the degenerated lumbar intervertebral disc (IVD). We are proposing replacement of the degenerated nucleus by a PVA/PVP polymeric hydrogel implant. We hypothesize that a polymeric hydrogel nucleus implant can restore the normal biomechanics of the denucleated IVD by mimicking the natural load transfer phenomenon as in case of the intact IVD. Lumbar IVDs (n = 15) were harvested from human cadavers. In the first part, specimens were tested in four different conditions for compression: Intact, bone in plug, denucleated and Implanted. Hydrogel nucleus implants were chosen to have line-to-line fit in the created nuclear cavity. In the second part, nucleus implant material (modulus) and geometric (height and diameter) parameters were varied and specimens (n = 9) were tested. Nucleus implants with line-to-line fit significantly restored (88%) the compressive stiffness of the denucleated IVD. The synergistic effect between the implant and the intact annulus resulted in the nonlinear increase in implanted IVD stiffness, where Poisson effect of the hydrogel played major role. Nucleus implant parameters were observed to have a significant effect on the compressive stiffness. All implants with modulus in the tested range restored the compressive stiffness. The undersize implants resulted in incomplete restoration while oversize implants resulted in complete restoration compared to the BI condition. Finite element models (FEM) were developed to simulate the actual test conditions and validated against the experimental results for all conditions. The annulus (defined as hyperelastic, isotropic) mainly determined the nonlinear response of the IVD. Validated FEMs predicted 120--3000 kPa as a feasible range for nucleus implant modulus. FEMs also predicted that overdiameter implant would be more effective than overheight implant in terms of stiffness restoration. Underdiameter implants, initially allowed inward deformation of the annulus and hence were less effective compared to underheight implants. This research successfully proved the feasibility of PVA/PVP polymeric hydrogel as a replacement for degenerated nucleus. This approach may reduce the abnormal stresses on the annulus and thus, prevent/postpone the degeneration of the annulus. A validated FEM can be used as a design tool for optimization of hydrogel nucleus implants design and related feasibility studies.

Erythropoietin Augments Survival of Glioma Cells After Radiation and Temozolomide

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hassouna, Imam; Sperling, Swetlana; Kim, Ella

2008-11-01

Purpose: Despite beneficial effects of irradiation/chemotherapy on survival of glioblastoma (GBM) patients, collateral damage to intact neural tissue leads to 'radiochemobrain' and reduced quality of life in survivors. For prophylactic neuroprotection, erythropoietin (EPO) is a promising candidate, provided that concerns regarding potential tumor promoting effects are alleviated. Methods and Materials: Human GBM-derived cell lines U87, G44, G112, and the gliosarcoma-derived line G28 were treated with EPO, with and without combinations of irradiation or temozolomide (TMZ). Responsiveness of glioma cells to EPO was measured by cell migration from spheroids, cell proliferation, and clonogenic survival. Implantation of U87 cells into brains ofmore » nude mice, followed 5 days later by EPO treatment (5,000 U/kg intraperitoneal every other day for 2 weeks) should reveal effects of EPO on tumor growth in vivo. Reverse transcriptase-polymerase chain reaction was performed for EPOR, HIF-1{alpha}, and epidermal growth factor receptor (EGFR)vIII in cell lines and 22 human GBM specimens. Results: EPO did not modulate basal glioma cell migration and stimulated proliferation in only one of four cell lines. Importantly, EPO did not enhance tumor growth in mouse brains. Preincubation of glioma cells with EPO for 3 h, followed by irradiation and TMZ for another 24 h, resulted in protection against chemoradiation-induced cytotoxicity in three cell lines. Conversely, EPO induced a dose-dependent decrease in survival of G28 gliosarcoma cells. In GBM specimens, expression of HIF-1{alpha} correlated positively with expression of EPOR and EGFRvIII. EPOR and EGFRvIII expression did not correlate. Conclusions: EPO is unlikely to appreciably influence basal glioma growth. However, concomitant use of EPO with irradiation/chemotherapy in GBM patients is not advisable.« less

40 projects in stem cell research, tissue engineering, tolerance induction and more (NRP46 "Implants and Transplants" 1999-2006).

PubMed

Thiel, Gilbert T

2007-03-02

Forty projects on stem cell research, tissue and matrix engineering, tolerance induction and other topics were supported by the Swiss National Research Program NRP46 (Implants, Transplants) from 1999-2006. The last project is devoted to developing stem cell lines from frozen surplus human embryos in Switzerland, which would otherwise have to be destroyed at the end of 2008. It is entitled JESP (Joint Embryonic Stem Cell Project) since it involves two Swiss universities, in vitro fertilisation centres and experts from the humanities (ethics and law) to handle this difficult problem. Over the years, stem cell transplantation and tissue/matrix engineering have drawn closer to each other and even developed synergies. Progress in stem cell research has been slower than anticipated, but a multitude of technical skills (phenotyping, isolation, transfection, induction of differentiation, labelling, expanding cells in culture, etc) were acquired. Understanding of stem cell biology has grown. The 7 projects on tissue and matrix engineering progressed closer to clinical applicability than the stem cell projects. Of 3 projects to implant encapsulated cells for the production of hormones (insulin, erythropoietin), one is close to clinical pilot studies with an advanced encapsulated device. Five projects were devoted to mechanisms of tolerance or the role of metzincins in chronic allograft nephropathy. Four studies in psychology and communication in transplantation were funded, as were 5 projects in ethics, law and the history of transplantation in Switzerland. The goal of NRP46 was to provide an impulse for research in these new fields and bring together experts from the humanities, biology and medicine to cope more effectively with the problems of regenerative medicine in the future. The majority of goals were attained, mainly in the basics.

Dual-Functionalized Graphene Oxide Based siRNA Delivery System for Implant Surface Biomodification with Enhanced Osteogenesis.

PubMed

Zhang, Li; Zhou, Qing; Song, Wen; Wu, Kaimin; Zhang, Yumei; Zhao, Yimin

2017-10-11

Surface functionalization by small interfering RNA (siRNA) is a novel strategy for improved implant osseointegration. A gene delivery system with safety and high transfection activity is a crucial factor for an siRNA-functionalized implant to exert its biological function. To this end, polyethylene glycol (PEG) and polyethylenimine (PEI) dual-functionalized graphene oxide (GO; nGO-PEG-PEI) may present a promising siRNA vector. In this study, nanosized nGO-PEG-PEI was prepared and optimized for siRNA delivery. Titania nanotubes (NTs) fabricated by anodic oxidation were biomodified with nGO-PEG-PEI/siRNA by cathodic electrodeposition, designated as NT-GPP/siRNA. NT-GPP/siRNA possessed benign cytocompatibility, as evaluated by cell adhesion and proliferation. Cellular uptake and knockdown efficiency of the NT-GPP/siRNA were assessed by MC3T3-E1 cells, which exhibited high siRNA delivery efficiency and sustained target gene silencing. Casein kinase-2 interacting protein-1 (Ckip-1) is a negative regulator of bone formation. siRNA-targeting Ckip-1 (siCkip-1) was introduced to the implant, and a series of in vitro and in vivo experiments were carried out to evaluate the osteogenic capacity of NT-GPP/siCkip-1. NT-GPP/siCkip-1 dramatically improved the in vitro osteogenic differentiation of MC3T3-E1 cells in terms of improved osteogenesis-related gene expression, and increased alkaline phosphatase (ALP) production, collagen secretion, and extracellular matrix (ECM) mineralization. Moreover, NT-GPP/siCkip-1 led to apparently enhanced in vivo osseointegration, as indicated by histological staining and EDX line scanning. Collectively, these findings suggest that NT-GPP/siRNA represents a practicable and promising approach for implant functionalization, showing clinical potential for dental and orthopedic applications.

THE NEOPLASTIC POTENTIALITIES OF MOUSE EMBRYO TISSUES

PubMed Central

Smith, William E.

1947-01-01

Epithelial tumors have been readily obtained by the implantation of embryo stomach tissue together with olive oil containing methylcholanthrene (with or without Scharlach R) in adult mice of homologous strain. The implanted tissue from the squamous portion of the stomach rapidly encysted the oil, and benign and malignant papillomas and squamous cell carcinomas soon arose from the stratified squamous lining of the cysts. Bits of the glandular portion of the stomach also formed cysts, but the gland cells underwent metaplasia in response to the carcinogen, altering first to transitional epithelium and then to a stratified squamous layer. So swiftly did these changes take place that nearly all of the tumors took origin from epithelium that had already become stratified and squamous, and the growths themselves were of this type. A single transitional cell carcinoma and an adenoacanthoma were procured, but no adenocarcinomas; nor did any benign papillomas develop, though they often resulted from the action of methylcholanthrene on the squamous portion of the embryo stomach. Search failed to disclose any distinctive precancerous changes in the gastric tissue. Five of the cancers were transplanted and they grew in every host. No tumors arose from any of the numerous control implants. Those consisting of glandular tissue formed cysts lined partly with columnar epithelium secreting mucus and partly with tubular glands equipped with chief and parietal cells in good condition. Pepsin and rennin were found in the fluid contained in these cysts, but no free hydrochloric acid. The enzymes were present also when the cysts contained methylcholanthrene and the glands had not yet been wholly replaced by metaplastic epithelium. The tumors appeared months sooner than when methylcholanthrene is injected into the stomach of adult animals or given by mouth; some of them were well established after 5 or 6 weeks. They arose regularly when the requisite experimental conditions were provided. The utilization of transplanted embryo tissue provides a means whereby gastric tumors free from bacterial infection can be procured swiftly and easily. PMID:19871629

A Primary Xenograft Model of Small Cell Lung Cancer Reveals Irreversible Changes in Gene Expression Imposed by Culture In-Vitro

PubMed Central

Daniel, Vincent C.; Marchionni, Luigi; Hierman, Jared S.; Rhodes, Jonathan T.; Devereux, Wendy L.; Rudin, Charles M.; Yung, Rex; Parmigani, Giovanni; Dorsch, Marion; Peacock, Craig D.; Watkins, D. Neil

2009-01-01

Traditional approaches to the preclinical investigation of cancer therapies rely on the use of established cell lines maintained in serum-based growth media. This is particularly true of small cell lung cancer (SCLC), where surgically resected tissue is rarely available. Recent attention has focused on the need for better models that preserve the integrity of cancer stem cell populations, as well as three-dimensional tumor-stromal interactions. Here we describe a primary xenograft model of SCLC in which endobronchial tumor specimens obtained from chemo-naive patients are serially propagated in vivo in immunodeficient mice. In parallel, cell lines grown in conventional tissue culture conditions were derived from each xenograft line, passaged for 6 months, and then re-implanted to generate secondary xenografts. Using the Affymetrix platform, we analyzed gene expression in primary xenograft, xenograft-derived cell line, and secondary xenograft, and compared these data to similar analyses of unrelated primary SCLC samples and laboratory models. When compared to normal lung, primary tumors, xenografts and cell lines displayed a gene expression signature specific for SCLC. Comparison of gene expression within the xenograft model identified a group of tumor-specific genes expressed in primary SCLC and xenografts that was lost during the transition to tissue culture, and that was not regained when the tumors were re-established as secondary xenografts. Such changes in gene expression may be a common feature of many cancer cell culture systems, with functional implications for the use of such models for preclinical drug development. PMID:19351829

Induction of carcinoembryonic antigen expression in a three-dimensional culture system

NASA Technical Reports Server (NTRS)

Jessup, J. M.; Brown, D.; Fitzgerald, W.; Ford, R. D.; Nachman, A.; Goodwin, T. J.; Spaulding, G.

1994-01-01

MIP-101 is a poorly differentiated human colon carcinoma cell line established from ascites that produces minimal amounts of carcinoembryonic antigen (CEA), a 180 kDa glycoprotein tumor marker, and nonspecific cross-reacting antigen (NCA), a related protein that has 50 and 90 kDa isoforms, in vitro in monolayer culture. MIP-101 produces CEA when implanted into the peritoneum of nude mice but not when implanted into subcutaneous tissue. We tested whether MIP-101 cells may be induced to express CEA when cultured on microcarrier beads in three-dimensional cultures, either in static cultures as non-adherent aggregates or under dynamic conditions in a NASA-designed low shear stress bioreactor. MIP- 101 cells proliferated well under all three conditions and increased CEA and NCA production 3 - 4 fold when grown in three-dimensional cultures compared to MIP-101 cells growing logarithmically in monolayers. These results suggest that three-dimensional growth in vitro simulates tumor function in vivo and that three-dimensional growth by itself may enhance production of molecules that are associated with the metastatic process.

Annual Research Report 1 October 1978-30 September 1979.

DTIC Science & Technology

1979-01-01

Roeder, R. G. and Rutter, W. J. Multiple acid polymerases in ribonucleic acid synthesis during sea urchin development. Biochemistry 9: 2543-2554...with ultrastructural transmission electron microscopy (TEM) studies and scanning electron microscopy ( SEM ) stud- ies of lateral ventricular lining and...1I alterations in animals about 100 days after Silastic implantation. SEM studies show flattening and stretching of ependymal cells in the dorsomedial

Production technology for high efficiency ion implanted solar cells

NASA Technical Reports Server (NTRS)

Kirkpatrick, A. R.; Minnucci, J. A.; Greenwald, A. C.; Josephs, R. H.

1978-01-01

Ion implantation is being developed for high volume automated production of silicon solar cells. An implanter designed for solar cell processing and able to properly implant up to 300 4-inch wafers per hour is now operational. A machine to implant 180 sq m/hr of solar cell material has been designed. Implanted silicon solar cells with efficiencies exceeding 16% AM1 are now being produced and higher efficiencies are expected. Ion implantation and transient processing by pulsed electron beams are being integrated with electrostatic bonding to accomplish a simple method for large scale, low cost production of high efficiency solar cell arrays.

Gravity and animal embryos

NASA Technical Reports Server (NTRS)

Wiley, Lynn M.

1989-01-01

Out of more than 4,500 rat hours in space there was only one experimental attempt (Cosmos 1129) at mating with an apparent absence of fertilization, implantation and subsequent development to term and partuition. Portions of this process were successfully flown, however, including the major portion of organogenesis in the rat (Cosmos 1524). These observations show that the cellular and molecular events underlying morphogenesis and differentiation in a small mammal can proceed normally in-utero under microgravity and other conditions encountered during short-duration flight. However, it is not known whether this situation will hold for larger mammals over several generations during extended missions that venture outside of near Earth. Furthermore, it is not understood why the previous attempt at obtaining copulation, fertilization and implantation in orbit failed but may be related to limitations of the rat habitat for meeting the preconditions for reproductive behavior. With respect to mammalian development it is important to appreciate that fertilization and development occur internally within the female and take a long time to complete and their success will, therefore, be contingent upon the maternal response to the space environment. One process central to development (the establishment of cell lines) is initiated prior to implantation by environmental asymmetries preceived by progenitor cells. These asymmetries appear to result from the formation of asymmetric cell-cell contacts and the concommitant development of an electrical axis across the progenitor cells. Other asymmetries were also documented. It is not known whether any of the known asymmetries perceived by progenitor cells are influenced by gravity vectors and/or by the maternal response to microgravity and other conditions encountered in space.

A PITX3-EGFP Reporter Line Reveals Connectivity of Dopamine and Non-dopamine Neuronal Subtypes in Grafts Generated from Human Embryonic Stem Cells.

PubMed

Niclis, Jonathan C; Gantner, Carlos W; Hunt, Cameron P J; Kauhausen, Jessica A; Durnall, Jennifer C; Haynes, John M; Pouton, Colin W; Parish, Clare L; Thompson, Lachlan H

2017-09-12

Development of safe and effective stem cell-based therapies for brain repair requires an in-depth understanding of the in vivo properties of neural grafts generated from human stem cells. Replacing dopamine neurons in Parkinson's disease remains one of the most anticipated applications. Here, we have used a human PITX3-EGFP embryonic stem cell line to characterize the connectivity of stem cell-derived midbrain dopamine neurons in the dopamine-depleted host brain with an unprecedented level of specificity. The results show that the major A9 and A10 subclasses of implanted dopamine neurons innervate multiple, developmentally appropriate host targets but also that the majority of graft-derived connectivity is non-dopaminergic. These findings highlight the promise of stem cell-based procedures for anatomically correct reconstruction of specific neuronal pathways but also emphasize the scope for further refinement in order to limit the inclusion of uncharacterized and potentially unwanted cell types. Copyright © 2017 The Author(s). Published by Elsevier Inc. All rights reserved.

Hexavalent chromium induces chromosome instability in human urothelial cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wise, Sandra S.; Holmes, Amie L.; Department of Radiation Oncology, Dana Farber Cancer Institute, 450 Brookline Ave., Boston, MA 02215

Numerous metals are well-known human bladder carcinogens. Despite the significant occupational and public health concern of metals and bladder cancer, the carcinogenic mechanisms remain largely unknown. Chromium, in particular, is a metal of concern as incidences of bladder cancer have been found elevated in chromate workers, and there is an increasing concern for patients with metal hip implants. However, the impact of hexavalent chromium (Cr(VI)) on bladder cells has not been studied. We compared chromate toxicity in two bladder cell lines; primary human urothelial cells and hTERT-immortalized human urothelial cells. Cr(VI) induced a concentration- and time-dependent increase in chromosome damagemore » in both cell lines, with the hTERT-immortalized cells exhibiting more chromosome damage than the primary cells. Chronic exposure to Cr(VI) also induced a concentration-dependent increase in aneuploid metaphases in both cell lines which was not observed after a 24 h exposure. Aneuploidy induction was higher in the hTERT-immortalized cells. When we correct for uptake, Cr(VI) induces a similar amount of chromosome damage and aneuploidy suggesting that the differences in Cr(VI) sensitivity between the two cells lines were due to differences in uptake. The increase in chromosome instability after chronic chromate treatment suggests this may be a mechanism for chromate-induced bladder cancer, specifically, and may be a mechanism for metal-induced bladder cancer, in general. - Highlights: • Hexavalent chromium is genotoxic to human urothelial cells. • Hexavalent chromium induces aneuploidy in human urothelial cells. • hTERT-immortalized human urothelial cells model the effects seen in primary urothelial cells. • Hexavalent chromium has a strong likelihood of being carcinogenic for bladder tissue.« less

Targeting single-walled carbon nanotubes for the treatment of breast cancer using photothermal therapy

NASA Astrophysics Data System (ADS)

Neves, Luís F. F.; Krais, John J.; Van Rite, Brent D.; Ramesh, Rajagopal; Resasco, Daniel E.; Harrison, Roger G.

2013-09-01

This paper focuses on the targeting of single-walled carbon nanotubes (SWNTs) for the treatment of breast cancer with minimal side effects using photothermal therapy. The human protein annexin V (AV) binds specifically to anionic phospholipids expressed externally on the surface of tumour cells and endothelial cells that line the tumour vasculature. A 2 h incubation of the SWNT-AV conjugate with proliferating endothelial cells followed by washing and near-infrared (NIR) irradiation at a wavelength of 980 nm was enough to induce significant cell death; there was no significant cell death with irradiation or the conjugate alone. Administration of the same conjugate i.v. in BALB/c female mice with implanted 4T1 murine mammary at a dose of 0.8 mg SWNT kg-1 and followed one day later by NIR irradiation of the tumour at a wavelength of 980 nm led to complete disappearance of implanted 4T1 mouse mammary tumours for the majority of the animals by 11 days since the irradiation. The combination of the photothermal therapy with the immunoadjuvant cyclophosphamide resulted in increased survival. The in vivo results suggest the SWNT-AV/NIR treatment is a promising approach to treat breast cancer.

125I Brachytherapy in Locally Advanced Nonsmall Cell Lung Cancer After Progression of Concurrent Radiochemotherapy

PubMed Central

Xiang, Zhanwang; Li, Guohong; Liu, Zhenyin; Huang, Jinhua; Zhong, Zhihui; Sun, Lin; Li, Chuanxing; Zhang, Funjun

2015-01-01

Abstract To investigate the safety and effectiveness of computed tomography (CT)-guided 125I seed implantation for locally advanced nonsmall cell lung cancer (NSCLC) after progression of concurrent radiochemotherapy (CCRT). We reviewed 78 locally advanced NSCLC patients who had each one cycle of first-line CCRT but had progressive disease identified from January 2006 to February 2015 at our institution. A total of 37 patients with 44 lesions received CT-guided percutaneous 125I seed implantation and second-line chemotherapy (group A), while 41 with 41 lesions received second-line chemotherapy (group B). Patients in group A and B received a total of 37 and 41 first cycle of CCRT treatment. The median follow-up was 19 (range 3–36) months. After the second treatment, the total response rate (RR) in tumor response accounted for 63.6% in group A, which was significantly higher than that of group B (41.5%) (P = 0.033). The median progression-free survival time (PFST) was 8.00 ± 1.09 months and 5.00 ± 0.64 months in groups A and B (P = 0.011). The 1-, 2-, and 3-year overall survival (OS) rates for group A were 56.8%, 16.2%, and 2.7%, respectively. For group B, OS rates were 36.6%, 9.8%, and 2.4%, respectively. The median OS time was 14.00 ± 1.82 months and 10.00 ± 1.37 months for groups A and B, respectively (P = 0.059). Similar toxicity reactions were found in both groups. Tumor-related clinical symptoms were significantly reduced and the patients’ quality of life was obviously improved. CT-guided 125I seed implantation proved to be potentially beneficial in treating localized advanced NSCLC; it achieved good local control rates and relieved clinical symptoms without increasing side effects. PMID:26656370

GABA stimulates human hepatocellular carcinoma growth through overexpressed GABAA receptor theta subunit

PubMed Central

Li, Yue-Hui; Liu, Yan; Li, Yan-Dong; Liu, Yan-Hong; Li, Feng; Ju, Qiang; Xie, Ping-Li; Li, Guan-Cheng

2012-01-01

AIM: To investigate the function of gamma-aminobutyric acid (GABA) and gamma-aminobutyric acid A receptor θ subunit (GABRQ) in hepatocellular carcinoma (HCC). METHODS: Semiquantitative polymerase chain reaction was used for detecting the expression of GABRQ receptor among HCC cell line HepG2, normal liver cell line L-02, non-malignant Chang’s liver cells, 8 samples of HCC tissues and paired non-cancerous tissues. HepG2 cells were treated with GABA at serial concentrations (0, 1, 10, 20, 40 and 60 μmol/L), and their proliferating abilities were analyzed with the methyl thiazolyl tetrazolium assay, cell cycle analysis and tumor implanted in nude mice. Small interfering RNA was used for knocking down the endogenous GABRQ in HepG2. Proliferating abilities of these cells treated with or without GABA were analyzed. RESULTS: We identified the overexpression of GABRQ in HCC cell lines and half of the tested HCC tissues. Knockdown of endogenous GABRQ expression in HepG2 attenuated HCC cell growth, suggesting its role in HCC cell viability. We studied the effect of GABA in the proliferation of GABRQ-positive cell lines in vitro and in vivo, and found that GABA increased HCC growth in a dose-dependent manner. Notably, the addition of GABA into the cell culture medium promoted the proliferation of GABRQ-expressing HepG2 cells, but not GABRQ-knockdown HepG2 cells, which means that GABA stimulates HepG2 cell growth through GABRQ. CONCLUSION: GABRQ play important roles in HCC development and progression and could be a promising molecular target for the development of new diagnostic and therapeutic strategies of HCC. PMID:22690081

Investigation of biomineralization by Raman spectroscopy

NASA Astrophysics Data System (ADS)

Fatscher, Robert William

Biomineralization is a process in which living organism grow composite materials consisting of inorganic and organic materials. This produces a composite material consisting of both inorganic and organic components, with superior mechanical properties. In the human body bone and dentin are both examples of biominerals. In this research Raman spectroscopy was used to characterize dentin from mice and human teeth, to determine composition. In the mouse tooth samples areas of irregular dentin were found, along the inside of the tooth, to be in the process of mineralization. By analyzing the samples along these areas we were able to determine the composition of dentin and track how it changed in these area. By analysis of the mineral to matrix ratio the areas of irregular dentin were determined to have less mineral present. Observations of other organic components and collagen in increased concentrations in this area suggested these area were in the process of biomineralization. The understanding of the structure of dentin and its biomineralization process is of crucial importance when trying reproduce dentin. Scientists and engineers are able to produce dentin minerals in vitro by culturing various dental stem cells. The ability to create dentin mineral from cells could lead to methods of repairing dentin in patients, or even lead to the creation of a completely engineered tooth. While dentin-like materials can be produced in a laboratory environment, analysis and comparison of the composition of these materials must be performed to ensure the mineral produced is consistent with dentin. Mineralized nodules from six different dental stem cell lines were cultured to produce a mineralized deposit. Utilizing Raman spectroscopy, we were able to determine cell source dependent differences in a variety of dental stem cells, and compare the mineral produced to native dentin. Orthopedic implants are implants used to replace damaged bone, examples include knee, hip and dental implants. These implants are designed to osteointegrate with the native healthy tissues in order to create a functionally stable and structural interface. Biomaterials such as hydroxyapatite and titania are known to increase the rate of bone regeneration in vivo.1 By accelerating the early response of bone forming cells to these implants, better fixation is achieved between the implant and the bone, shortening recovery times and increasing the viability of these implants. In the last part of this research an investigation of osteoblasts cultured at 14 days on five different heat-treated titania substrates was investigated by Raman spectroscopy, in order to observe the initial cellular response to the titania substrates. The heat-treatment of titania changes the amount of oxygen on it's surface which in turn effects the surface energy. A change in the surface energy of a material will affect the cellular response, by culturing cells on various heat-treated titania substrates a relationship between the surface energy and cellular response can be investigated. A faster cellular response would lead to an increased rate of bone regeneration shortening healing times and allowing for better fixation of the implant.

Recurrent genomic instability of chromosome 1q in neural derivatives of human embryonic stem cells

PubMed Central

Varela, Christine; Denis, Jérôme Alexandre; Polentes, Jérôme; Feyeux, Maxime; Aubert, Sophie; Champon, Benoite; Piétu, Geneviève; Peschanski, Marc; Lefort, Nathalie

2012-01-01

Human pluripotent stem cells offer a limitless source of cells for regenerative medicine. Neural derivatives of human embryonic stem cells (hESCs) are currently being used for cell therapy in 3 clinical trials. However, hESCs are prone to genomic instability, which could limit their clinical utility. Here, we report that neural differentiation of hESCs systematically produced a neural stem cell population that could be propagated for more than 50 passages without entering senescence; this was true for all 6 hESC lines tested. The apparent spontaneous loss of evolution toward normal senescence of somatic cells was associated with a jumping translocation of chromosome 1q. This chromosomal defect has previously been associated with hematologic malignancies and pediatric brain tumors with poor clinical outcome. Neural stem cells carrying the 1q defect implanted into the brains of rats failed to integrate and expand, whereas normal cells engrafted. Our results call for additional quality controls to be implemented to ensure genomic integrity not only of undifferentiated pluripotent stem cells, but also of hESC derivatives that form cell therapy end products, particularly neural lines. PMID:22269325

[Long-term results of posterior chamber phakic intraocular lens implantation for correction of high ametropia].

PubMed

Le Loir, M; Cochener, B

2012-06-01

To assess efficacy, stability and safety of posterior chamber phakic intraocular lens implantation with STAAR Visian ICL for correction of high ametropia, with a mean follow-up of 5 years (3.5-10 years). Ninety eyes of 53 highly ametropic patients (45 myopia, ten hyperopia and 35 with mixed astigmatism) were included in a retrospective single-surgeon study, using primarily the V4 ICL model (87 eyes). We studied pre- and postoperative refractive efficacy, endothelial cell density, crystalline lens opacification and intraocular clearances within the various compartments of the eye. Mean uncorrected visual acuity was 0.77 at the 12th postoperative month; 17 of 90 eyes required adjunctive photoablation for residual astigmatism. Forty-eight percent of eyes gained at least one line of best corrected visual acuity. After implantation, the decrease in endothelial cell density remained stable at 0.69%/year, and 91% of eyes showed no opacification of the crystalline lens. Mean endothelium-ICL and ICL-crystalline lens distances were 2.41 mm and 0.52 mm respectively. Overall patient satisfaction achieved was 96% at 36 months postoperatively. These results demonstrate efficacy, stability and safety of the ICL V4 phakic IOL for the correction of high ametropia. Long-term follow-up did not show a significant increase in cataract formation in implanted eyes. Copyright © 2012. Published by Elsevier Masson SAS.

Implantation of ArtificialIris, a CustomFlex irisprosthesis, in a trauma patient with an Artisan lens

PubMed Central

Doroodgar, Farideh; Jabbarvand, Mahmoud; Niazi, Feizollah; Niazi, Sana; Sanginabadi, Azad

2017-01-01

Abstract Purpose: To evaluate probable complications of ArtificialIris implantation with iris fixated intraocular lens. Method: Development of photophobia, glare, and psychological strain during face-to-face communication in a 23-year-old man with a widespread traumatic iris defect terminate to make a decision for performing implantation of an ArtificialIris (Humanoptics, Erlangen, Germany) under the remnant iris without removing the patient's existing Artisan lens. Results: Without any intraoperative or postoperative complications, the patient's visual acuity increased by 1 line, the endothelial cell loss was comparable with the cell loss associated with standard cataract surgery, and the anterior-chamber depth and anterior-chamber anatomy did not change. At the final follow-up examination, the mean intraocular pressure did not differ from baseline, and we achieved high level of patient satisfaction and subjective vision improvement. We discuss the particular importance of considering the patient's expectations, the appropriate measurements, ways to perfect color evaluation, and the types of ArtificialIris products. Conclusion: The implantation of the ArtificialIris in patients with aphakic iris-supported lenses (ie, pre-existing Artisan lenses) is a feasible approach and a useful option for patients with thin irises and iris hypoplasia who are at risk of subluxation or the dislocation of the posterior-chamber intraocular lens (PCIOL), and also those with sclerally fixed PCIOLs. PMID:29137026

Blastocyst-like structures generated solely from stem cells.

PubMed

Rivron, Nicolas C; Frias-Aldeguer, Javier; Vrij, Erik J; Boisset, Jean-Charles; Korving, Jeroen; Vivié, Judith; Truckenmüller, Roman K; van Oudenaarden, Alexander; van Blitterswijk, Clemens A; Geijsen, Niels

2018-05-01

The blastocyst (the early mammalian embryo) forms all embryonic and extra-embryonic tissues, including the placenta. It consists of a spherical thin-walled layer, known as the trophectoderm, that surrounds a fluid-filled cavity sheltering the embryonic cells 1 . From mouse blastocysts, it is possible to derive both trophoblast 2 and embryonic stem-cell lines 3 , which are in vitro analogues of the trophectoderm and embryonic compartments, respectively. Here we report that trophoblast and embryonic stem cells cooperate in vitro to form structures that morphologically and transcriptionally resemble embryonic day 3.5 blastocysts, termed blastoids. Like blastocysts, blastoids form from inductive signals that originate from the inner embryonic cells and drive the development of the outer trophectoderm. The nature and function of these signals have been largely unexplored. Genetically and physically uncoupling the embryonic and trophectoderm compartments, along with single-cell transcriptomics, reveals the extensive inventory of embryonic inductions. We specifically show that the embryonic cells maintain trophoblast proliferation and self-renewal, while fine-tuning trophoblast epithelial morphogenesis in part via a BMP4/Nodal-KLF6 axis. Although blastoids do not support the development of bona fide embryos, we demonstrate that embryonic inductions are crucial to form a trophectoderm state that robustly implants and triggers decidualization in utero. Thus, at this stage, the nascent embryo fuels trophectoderm development and implantation.

Antioxidant, Antiproliferative, and Antiangiogenesis Effects of Polyphenol-Rich Seaweed (Sargassum muticum)

PubMed Central

Namvar, Farideh; Mohamad, Rosfarizan; Baharara, Javad; Zafar-Balanejad, Saeedeh; Fargahi, Fahimeh; Rahman, Heshu Sulaiman

2013-01-01

In the present study, we evaluated the effect of brown seaweeds Sargassum muticum methanolic extract (SMME), against MCF-7 and MDA-MB-231 breast cancer cell lines proliferation. This algae extract was also evaluated for reducing activity and total polyphenol content. The MTT assay results indicated that the extracts were cytotoxic against breast cancer cell lines in a dose-dependent manner, with IC50 of 22 μg/ml for MCF-7 and 55 μg/ml for MDA-MB-231 cell lines. The percentages of apoptotic MCF-7-treated cells increased from 13% to 67% by increasing the concentration of the SMME. The antiproliferative efficacy of this algal extract was positively correlated with the total polyphenol contents, suggesting a causal link related to extract content of phenolic acids. Cell cycle analysis showed a significant increase in the accumulation of SMME-treated cells at sub-G1 phase, indicating the induction of apoptosis by SMME. Further apoptosis induction was confirmed by Hoechst 33342 and AO/PI staining. Also SMME implanted in vivo into fertilized chicken eggs induced dose-related antiangiogenic activity in the chorioallantoic membrane (CAM). Our results imply a new insight on the novel function of Sargassum muticum polyphenol-rich seaweed in cancer research by induction of apoptosis, antioxidant, and antiangiogenesis effects. PMID:24078922

Protein Secretion Is Required for Pregnancy-Associated Plasma Protein-A to Promote Lung Cancer Growth In Vivo

PubMed Central

Pan, Hong; Hanada, Sayaka; Zhao, Jun; Mao, Li; Ma, Mark Zhi-Qing

2012-01-01

Pregnancy-associated plasma protein-A (PAPPA) has been reported to regulate the activity of insulin-like growth factor (IGF) signal pathway through proteolytic degradation of IGF binding proteins (IGFBPs) thereby increasing the local concentration of free IGFs available to receptors. In this study we found that PAPPA is secreted from two out of seven lung cancer cell lines examined. None of immortalized normal bronchial epithelial cells (HBE) tested secrets PAPPA. There is no correlation between expression level and secretion of PAPPA in these cells. A cell line over-expressing PAPPA accompanied with secretion shows no notable changes in proliferation under cell culture conditions in vitro, but displays significantly augmentation of tumor growth in vivo in a xenograft model. In contrast, a cell line over-expressing PAPPA without secretion exhibits reduction of tumor growth both in vitro and in vivo. Down-regulation of PAPPA expression and secretion by RNAi knockdown decreases tumor growth after implanted in vivo. The tumor promoting activity of PAPPA appears to be mediated mainly through augmentation of the IGF signaling pathway as indicated by notable increases in downstream Akt kinase phosphorylation in tumor samples. Our results indicate that PAPPA secretion may play an important role in lung cancer growth and progression. PMID:23152806

Characterization and antibacterial performance of electrodeposited chitosan-vancomycin composite coatings for prevention of implant-associated infections.

PubMed

Ordikhani, F; Tamjid, E; Simchi, A

2014-08-01

Orthopaedic implant-associated infections are one of the most serious complications in orthopaedic surgery and a major cause of implant failure. In the present work, drug-eluting coatings based on chitosan containing various amounts of vancomycin were prepared by a cathodic electrophoretic deposition process on titanium foils. A three-step release mechanism of the antibiotic from the films in a phosphate-buffered saline solution was noticed. At the early stage, physical encapsulation of the drug in the hydrogel network controlled the release rate. At the late stage, however, in vitro degradation/deattachment of chitosan was responsible for the controlled release. Cytotoxicity evaluation of the drug-eluting coatings via culturing in human osteosarcoma cells (MG-63 osteoblast-like cell line) showed no adverse effect on the biocompatibility. Antibacterial tests against Gram-positive Staphylococcus aureus also demonstrated that the infection risk of titanium foils was significantly reduced due to the antibiotic release. Additionally, in vitro electrochemical corrosion studies by polarization technique revealed that the corrosion current density was significantly lower for the titanium foils with drug-eluting coatings compared to that of uncoated titanium. Copyright © 2014 Elsevier B.V. All rights reserved.

Placement of central venous port catheters and peripherally inserted central catheters in the routine clinical setting of a radiology department: analysis of costs and intervention duration learning curve.

PubMed

Rotzinger, Roman; Gebauer, Bernhard; Schnapauff, Dirk; Streitparth, Florian; Wieners, Gero; Grieser, Christian; Freyhardt, Patrick; Hamm, Bernd; Maurer, Martin H

2017-12-01

Background Placement of central venous port catheters (CVPS) and peripherally inserted central catheters (PICC) is an integral component of state-of-the-art patient care. In the era of increasing cost awareness, it is desirable to have more information to comprehensively assess both procedures. Purpose To perform a retrospective analysis of interventional radiologic implantation of CVPS and PICC lines in a large patient population including a cost analysis of both methods as well as an investigation the learning curve in terms of the interventions' durations. Material and Methods All CVPS and PICC line related interventions performed in an interventional radiology department during a three-year period from January 2011 to December 2013 were examined. Documented patient data included sex, venous access site, and indication for CVPS or PICC placement. A cost analysis including intervention times was performed based on the prorated costs of equipment use, staff costs, and expenditures for disposables. The decrease in intervention duration in the course of time conformed to the learning curve. Results In total, 2987 interventions were performed by 16 radiologists: 1777 CVPS and 791 PICC lines. An average implantation took 22.5 ± 0.6 min (CVPS) and 10.1 ± 0.9 min (PICC lines). For CVPS, this average time was achieved by seven radiologists newly learning the procedures after performing 20 CVPS implantations. Total costs per implantation were €242 (CVPS) and €201 (PICC lines). Conclusion Interventional radiologic implantations of CVPS and PICC lines are well-established procedures, easy to learn by residents, and can be implanted at low costs.

Role of Pancreatic Cancer-derived Exosomes in Salivary Biomarker Development*

PubMed Central

Lau, Chang; Kim, Yong; Chia, David; Spielmann, Nadine; Eibl, Guido; Elashoff, David; Wei, Fang; Lin, Yi-Ling; Moro, Aune; Grogan, Tristan; Chiang, Samantha; Feinstein, Eric; Schafer, Christopher; Farrell, James; Wong, David T. W.

2013-01-01

Recent studies have demonstrated that discriminatory salivary biomarkers can be readily detected upon the development of systemic diseases such as pancreatic cancer, breast cancer, lung cancer, and ovarian cancer. However, the utility of salivary biomarkers for the detection of systemic diseases has been undermined due to the absence of the biological and mechanistic rationale as to why distal diseases from the oral cavity would lead to the development of discriminatory biomarkers in saliva. Here, we examine the hypothesis that pancreatic tumor-derived exosomes are mechanistically involved in the development of pancreatic cancer-discriminatory salivary transcriptomic biomarkers. We first developed a pancreatic cancer mouse model that yielded discriminatory salivary biomarkers by implanting the mouse pancreatic cancer cell line Panc02 into the pancreas of the syngeneic host C57BL/6. The role of pancreatic cancer-derived exosomes in the development of discriminatory salivary biomarkers was then tested by engineering a Panc02 cell line that is suppressed for exosome biogenesis, implanting into the C56BL/6 mouse, and examining whether the discriminatory salivary biomarker profile was ablated or disrupted. Suppression of exosome biogenesis results in the ablation of discriminatory salivary biomarker development. This study supports that tumor-derived exosomes provide a mechanism in the development of discriminatory biomarkers in saliva and distal systemic diseases. PMID:23880764

Heterozygous Deficiency of PHD2 Restores Tumor Oxygenation and Inhibits Metastasis via Endothelial Normalization

PubMed Central

Loges, Sonja; Schmidt, Thomas; Jonckx, Bart; Tian, Ya-Min; Lanahan, Anthony A.; Pollard, Patrick; de Almodovar, Carmen Ruiz; De Smet, Frederik; Vinckier, Stefan; Aragonés, Julián; Debackere, Koen; Luttun, Aernout; Wyns, Sabine; Jordan, Benedicte; Pisacane, Alberto; Gallez, Bernard; Lampugnani, Maria Grazia; Dejana, Elisabetta; Simons, Michael; Ratcliffe, Peter; Maxwell, Patrick; Carmeliet, Peter

2014-01-01

SUMMARY A key function of blood vessels, to supply oxygen, is impaired in tumors because of abnormalities in their endothelial lining. PHD proteins serve as oxygen sensors and may regulate oxygen delivery. We therefore studied the role of endothelial PHD2 in vessel shaping by implanting tumors in PHD2+/− mice. Haplodeficiency of PHD2 did not affect tumor vessel density or lumen size, but normalized the endothelial lining and vessel maturation. This resulted in improved tumor perfusion and oxygenation and inhibited tumor cell invasion, intravasation, and metastasis. Haplodeficiency of PHD2 redirected the specification of endothelial tip cells to a more quiescent cell type, lacking filopodia and arrayed in a phalanx formation. This transition relied on HIF-driven upregulation of (soluble) VEGFR-1 and VE-cadherin. Thus, decreased activity of an oxygen sensor in hypoxic conditions prompts endothelial cells to readjust their shape and phenotype to restore oxygen supply. Inhibition of PHD2 may offer alternative therapeutic opportunities for anticancer therapy. PMID:19217150

Human Corneal Limbal-Epithelial Cell Response to Varying Silk Film Geometric Topography In Vitro

PubMed Central

Lawrence, Brian D.; Pan, Zhi; Liu, Aihong; Kaplan, David L.; Rosenblatt, Mark I.

2012-01-01

Silk fibroin films are a promising class of biomaterials that have a number of advantages for use in ophthalmic applications due to their transparent nature, mechanical properties and minimal inflammatory response upon implantation. Freestanding silk films with parallel line and concentric ring topographies were generated for in vitro characterization of human corneal limbal-epithelial (HCLE) cell response upon differing geometric patterned surfaces. Results indicated that silk film topography significantly affected initial HCLE culture substrate attachment, cellular alignment, cell-to-cell contact formation, actin cytoskeleton alignment, and focal adhesion (FA) localization. Most notably, parallel line patterned surfaces displayed a 36%–54% increase on average in initial cell attachment, which corresponded to an over 2-fold increase in FA localization when compared to other silk film surfaces and controls. In addition, distinct localization of FA formation was observed along the edges for all patterned silk film topographies. In conclusion, silk film feature topography appears to help direct corneal epithelial cell response and cytoskeleton development, especially in regards to FA distribution, in vitro. PMID:22705042

Down to 2 nm Ultra Shallow Junctions : Fabrication by IBS Plasma Immersion Ion Implantation Prototype PULSION registered

DOE Office of Scientific and Technical Information (OSTI.GOV)

Torregrosa, Frank; Etienne, Hasnaa; Mathieu, Gilles

Classical beam line implantation is limited in low energies and cannot achieve P+/N junctions requirements for <45nm node. Compared to conventional beam line ion implantation, limited to a minimum of about 200 eV, the efficiency of Plasma Immersion Ion Implantation (PIII) is no more to prove for the realization of Ultra Shallow Junctions (USJ) in semiconductor applications: this technique allows to get ultimate shallow profiles (as implanted) thanks to no lower limitation of energy and offers high dose rate. In the field of the European consortium NANOCMOS, Ultra Shallow Junctions implanted on a semi-industrial PIII prototype (PULSION registered ) designedmore » by the French company IBS, have been studied. Ultra shallow junctions implanted with BF3 at acceleration voltages down to 20V were realized. Contamination level, homogeneity and depth profile are studied. The SIMS profiles obtained show the capability to make ultra shallow profiles (as implanted) down to 2nm.« less

Utility Of Nitric Oxide And Hydrogen Sulfide-Releasing Chimeras As Anticancer Agents.

PubMed

Kashfi, Khosrow

2015-08-01

Aspirin is chemopreventive but has significant side effects. We developed NOSH-aspirin a safer, nitric oxide and hydrogen sulfide releasing hybrid. Here we report on NOSH-aspirin as an anti-inflammatory and its effects on human cancer cell kinetics and various cancer xenografts. Anti-inflammatory: Carageenan rat paw edema model. Cancer cell lines: Colon, HT-29, HCT 15, SW 480; breast, MCF-7, MDA-MB-231; pancreas, MIA PaCa2, BxPC3. Normal cell lines: human mammary, HMEpC; pancreatic epithelial, ACBRI 515. Xenografts: nude mice implanted with HT-29, MDA-MB-231, MIA PaCa2 cells, were treated with NOSH-aspirin (100mg/kg/d) or vehicle. After 3 weeks, mice were sacrificed, tumors excised, weighed, and fixed for IHC studies. NOSH-aspirin significantly reduced paw edema as function of time. NOSH-aspirin's IC 50 in nM at 24h for cell growth inhibition ranged from 50±2 to 250±10 in the cancer cell lines and about 400-fold higher in the normal cell lines. The cell growth inhibitory effects were due to a dose-dependent induction of apoptosis and cell cycle arrest (G0/G1), leading to reductions in cell proliferation. In xenografts, NOSH-aspirin had no effect on the weight of the mice. Tumor volume was reduced as a function of treatment time. At sacrifice, tumor mass reductions were colon: 89%, P=0.005; breast: 91%, P=0.006; pancreas: 75%, P=0.0031. Growth inhibition was due to reduced proliferation (decreased PCNA expression), and induction of apoptosis (increased TUNEL positive cells). NOSH-aspirin is a potent anti-inflammatory, preferentially affecting cancer cells and targets parameters important in determining cellular mass. Copyright © 2015. Published by Elsevier B.V.

Development of pulsed processes for the manufacture of solar cells. Quarterly progress report No. 3, April--July 1978

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1978-07-01

Third quarter results under a program to develop ion implantation and specialized, associated processes necessary to achieve automated production of silicon solar cells are described. An ion implantation facility development for solar cell production is described, and a design for an automated production implanter is presented. Also, solar cell development efforts using combined ion implantation and pulsed energy techniques are discussed. Cell performance comparisons have also been made in which junctions and back surface fields were prepared by diffusion and ion implantation. A model is presented to explain the mechanism of ion implantation damage annealing using pulsed energy sources. Functionalmore » requirements have been determined for a pulsed electron beam processor for annealing ion implantation damage at a rate compatible with a 100 milliampere ion implanter. These rates result in a throughput of 100 megawatts of solar cell product per year.« less

In vitro biological outcome of laser application for modification or processing of titanium dental implants.

PubMed

Hindy, Ahmed; Farahmand, Farzam; Tabatabaei, Fahimeh Sadat

2017-07-01

There are numerous functions for laser in modern implant dentistry including surface treatment, surface coating, and implant manufacturing. As laser application may potentially improve osseointegration of dental implants, we systematically reviewed the literature for in vitro biological responses to laser-modified or processed titanium dental implants. The literature was searched in PubMed, ISI Web, and Scopus, using keywords "titanium dental implants," "laser," "biocompatibility," and their synonyms. After screening the 136 references obtained, 28 articles met the inclusion criteria. We found that Nd:YAG laser was the most commonly used lasers in the treatment or processing of titanium dental implants. Most of the experiments used cell attachment and cell proliferation to investigate bioresponses of the implants. The most commonly used cells in these assays were osteoblast-like cells. Only one study was conducted in stem cells. These in vitro studies reported higher biocompatibility in laser-modified titanium implants. It seems that laser radiation plays a vital role in cell response to dental implants; however, it is necessary to accomplish more studies using different laser types and parameters on various cells to offer a more conclusive result.

Electrospun nanofibrous scaffolds increase the efficacy of stem cell-mediated therapy of surgically resected glioblastoma

PubMed Central

Bagó, Juli R.; Pegna, Guillaume J.; Okolie, Onyi; Mohiti-Asli, Mahsa; Loboa, Elizabeth G.; Hingtgen, Shawn D.

2017-01-01

Engineered stem cell (SC)-based therapy holds enormous promise for treating the incurable brain cancer glioblastoma (GBM). Retaining the cytotoxic SCs in the surgical cavity after GBM resection is one of the greatest challenges to this approach. Here, we describe a biocompatible electrospun nanofibrous scaffold (bENS) implant capable of delivering and retaining tumor-homing cytotoxic stem cells that suppress recurrence of post-surgical GBM. As a new approach to GBM therapy, we created poly(l-lactic acid) (PLA) bENS bearing drug-releasing human mesenchymal stem cells (hMSCs). We discovered that bENS-based implant increased hMSC retention in the surgical cavity 5-fold and prolonged persistence 3-fold compared to standard direct injection using our mouse model of GBM surgical resection/recurrence. Time-lapse imaging showed cytotoxic hMSC/bENS treatment killed co-cultured human GBM cells, and allowed hMSCs to rapidly migrate off the scaffolds as they homed to GBMs. In vivo, bENS loaded with hMSCs releasing the anti-tumor protein TRAIL (bENSsTR) reduced the volume of established GBM xenografts 3-fold. Mimicking clinical GBM patient therapy, lining the post-operative GBM surgical cavity with bENSsTR implants inhibited the re-growth of residual GBM foci 2.3-fold and prolonged post-surgical median survival from 13.5 to 31 days in mice. These results suggest that nanofibrous-based SC therapies could be an innovative new approach to improve the outcomes of patients suffering from terminal brain cancer. PMID:27016620

Improved bone marrow stromal cell adhesion on micropatterned titanium surfaces.

PubMed

Iskandar, Maria E; Cipriano, Aaron F; Lock, Jaclyn; Gott, Shannon C; Rao, Masaru P; Liu, Huinan

2012-01-01

Implant longevity is desired for all bone replacements and fixatives. Titanium (Ti) implants fail due to lack of juxtaposed bone formation, resulting in implant loosening. Implant surface modifications have shown to affect the interactions between the implant and bone. In clinical applications, it is crucial to improve osseointegration and implant fixation at the implant and bone interface. Moreover, bone marrow derived cells play a significant role for implant and tissue integration. Therefore, the objective of this study is to investigate how surface micropatterning on Ti influences its interactions with bone marrow derived cells containing mesenchymal and hematopoietic stem cells. Bone marrow derived mesenchymal stem cells (BMSC) have the capability of differentiating into osteoblasts that contribute to bone growth, and therefore implant/bone integration. Hematopoietic stem cell derivatives are precursor cells that contribute to inflammatory response. By using all three cells naturally contained within bone marrow, we mimic the physiological environment to which an implant is exposed. Primary rat bone marrow derived cells were seeded onto Ti with surfaces composed of arrays of grooves of equal width and spacing ranging from 0.5 to 50 µm, fabricated using a novel plasma-based dry etching technique. Results demonstrated enhanced total cell adhesion on smaller micrometer-scale Ti patterns compared with larger micrometer-scale Ti patterns, after 24-hr culture. Further studies are needed to determine bone marrow derived cell proliferation and osteogenic differentiation potential on micropatterned Ti, and eventually nanopatterned Ti.

Research on Blastocyst Implantation Essential Factors (BIEFs).

PubMed

Yoshinaga, Koji

2010-06-01

Blastocyst implantation is a process of interaction between embryo and the uterus. To understand this process, this review tries to summarize what blastocyst implantation essential factors (BIEFs) play what roles, as well as where in the uterus and at what stage of implantation process. Addition of more new data to this kind of compilation of information will help the development of diagnosis and treatment of infertility caused by implantation failure. The major, important cells of the endometrial cells that interact with invading blastocyst (trophoblast) are luminal epithelial cells, stromal cells (decidual cells) and resident immune cells. BIEFs regulate these cells to successfully maintain pregnancy.

The secreted protein ANGPTL2 promotes metastasis of osteosarcoma cells through integrin α5β1, p38 MAPK, and matrix metalloproteinases.

PubMed

Odagiri, Haruki; Kadomatsu, Tsuyoshi; Endo, Motoyoshi; Masuda, Tetsuro; Morioka, Masaki Suimye; Fukuhara, Shigetomo; Miyamoto, Takeshi; Kobayashi, Eisuke; Miyata, Keishi; Aoi, Jun; Horiguchi, Haruki; Nishimura, Naotaka; Terada, Kazutoyo; Yakushiji, Toshitake; Manabe, Ichiro; Mochizuki, Naoki; Mizuta, Hiroshi; Oike, Yuichi

2014-01-21

The tumor microenvironment can enhance the invasive capacity of tumor cells. We showed that expression of angiopoietin-like protein 2 (ANGPTL2) in osteosarcoma (OS) cell lines increased and the methylation of its promoter decreased with time when grown as xenografts in mice compared with culture. Compared with cells grown in normal culture conditions, the expression of genes encoding DNA demethylation-related enzymes increased in tumor cells implanted into mice or grown in hypoxic, serum-starved culture conditions. ANGPTL2 expression in OS cell lines correlated with increased tumor metastasis and decreased animal survival by promoting tumor cell intravasation mediated by the integrin α5β1, p38 mitogen-activated protein kinase, and matrix metalloproteinases. The tolloid-like 1 (TLL1) protease cleaved ANGPTL2 into fragments in vitro that did not enhance tumor progression when overexpressed in xenografts. Expression of TLL1 was weak in OS patient tumors, suggesting that ANGPTL2 may not be efficiently cleaved upon secretion from OS cells. These findings demonstrate that preventing ANGPTL2 signaling stimulated by the tumor microenvironment could inhibit tumor cell migration and metastasis.

Exploring the Limits of Cell Adhesion under Shear Stress within Physiological Conditions and beyond on a Chip.

PubMed

Stamp, Melanie E M; Jötten, Anna M; Kudella, Patrick W; Breyer, Dominik; Strobl, Florian G; Geislinger, Thomas M; Wixforth, Achim; Westerhausen, Christoph

2016-10-21

Cell adhesion processes are of ubiquitous importance for biomedical applications such as optimization of implant materials. Here, not only physiological conditions such as temperature or pH, but also topographical structures play crucial roles, as inflammatory reactions after surgery can diminish osseointegration. In this study, we systematically investigate cell adhesion under static, dynamic and physiologically relevant conditions employing a lab-on-a-chip system. We screen adhesion of the bone osteosarcoma cell line SaOs-2 on a titanium implant material for pH and temperature values in the physiological range and beyond, to explore the limits of cell adhesion, e.g., for feverish and acidic conditions. A detailed study of different surface roughness R q gives insight into the correlation between the cells' abilities to adhere and withstand shear flow and the topography of the substrates, finding a local optimum at R q = 22 nm. We use shear stress induced by acoustic streaming to determine a measure for the ability of cell adhesion under an external force for various conditions. We find an optimum of cell adhesion for T = 37 °C and pH = 7.4 with decreasing cell adhesion outside the physiological range, especially for high T and low pH. We find constant detachment rates in the physiological regime, but this behavior tends to collapse at the limits of 41 °C and pH 4.

Effects of 60-Heartz electric and magnetic fields on implanted cardiac pacemakers. Final report. [Hazards of power transmission line frequencies

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bridges, J.E.; Frazier, M.J.

1979-09-01

The effects of 60-Hz electric and magnetic fields of exta-high voltage (EHV) transmission lines on the performance of implanted cardiac pacemakers were studied by: (1) in vitro bench tests of a total of thirteen cardiac pacemakers; (2) in vivo tests of six implanted cardiac pacemakers in baboons; and (3) non-hazardous skin measurement tests on four humans. Analytical methods were developed to predict the thresholds of body current and electric fields capable of affecting normal pacemaker operation in humans. The field strengths calculated to alter implanted pacemaker performance were compared with the range of maximum electric and magnetic field strengths amore » human would normally encounter under transmission lines of various voltages. Results indicate that the electric field or body current necessary to alter the normal operation of pacemakers is highly dependent on the type of pacemaker and the location of the implanted electrodes. However, cardiologists have not so far detected harmful effects of pacemaker reversion to the asynchronous mode in current types of pacemakers and with present methods of implantation. Such interferences can be eliminated by using advanced pacemakers less sensitive to 60-Hz voltages or by using implantation lead arrangements less sensitive to body current.« less

Orthotopic tumorgrafts in nude mice: A new method to study human prostate cancer.

PubMed

Saar, Matthias; Körbel, Christina; Linxweiler, Johannes; Jung, Volker; Kamradt, Jörn; Hasenfus, Andrea; Stöckle, Michael; Unteregger, Gerhard; Menger, Michael D

2015-10-01

In vivo model systems in prostate cancer research that authentically reproduce tumor growth are still sparse. While orthotopic implantation is technically difficult, particularly in the mouse, most models favor subcutaneous tumor growth. This however provides little information about natural tumor growth behavior and tumor stroma interaction. Furthermore, established prostate cancer cell lines grown as in vivo xenografts are not able to reflect the variety of tumor specific growth patterns and growth behavior in men. Primary cell cultures are difficult to handle and an induction of orthotopic tumors has not been successful yet. Therefore, a tumorgraft model using tumor tissue from prostatectomy specimens was developed. Balb/c nude mice were used to graft fresh prostate tumor tissue by renal subcapsular and orthotopic implantation. Testosterone propionate was supplemented. Animals were tracked by means of 30 MHz ultrasound to monitor tumor engraftment and growth. Autopsy, histology, PSA measurements as well as immunostaining and PCR for human tissue were performed to confirm orthotopic tumor growth. Renal subcapsular engraftment was seen in 2 of 3 mice. Orthotopic engraftment was observed in 7 of 11 animals (63.6%) with an overall engraftment of 5 out of 9 patient specimens (55.6%). Ultrasound confirmed the tumor growth over time. Of interest, the tumorgrafts not only retained essential features of the parental tumors, but also stained positive for tumor specific markers such as AR, PSA, and AMACR. Tumor positive animals showed highly elevated serum PSA levels with confirmation of a human specific PCR sequence and a human endothelial cell lining in the tumor vessels. Standardized implantation of fresh tumor tissue in nude mice prostates generates tumorgrafts with histological properties of organ-confined prostate cancer. These tumorgrafts display a new approach for an optimized in vivo model of prostate cancer and will allow further investigations on specific pathways of tumor initiation and progression as well as therapeutic response. © 2015 Wiley Periodicals, Inc.

In vitro bioactivity of micro metal injection moulded stainless steel with defined surface features.

PubMed

Bitar, Malak; Friederici, Vera; Imgrund, Philipp; Brose, Claudia; Bruinink, Arie

2012-05-04

Micrometre- and nanometre-scale surface structuring with ordered topography features may dramatically enhance orthopaedic implant integration. In this study we utilised a previously optimised micron metal injection moulding (µ-MIM) process to produce medical grade stainless steel surfaces bearing micrometre scale, protruding, hemispheres of controlled dimensions and spatial distribution. Additionally, the structured surfaces were characterised by the presence of submicrometre surface roughness resulting from metal grain boundary formation. Following cytocompatibility (cytotoxicity) evaluation using 3T3 mouse fibroblast cell line, the effect on primary human cell functionality was assessed focusing on cell attachment, shape and cytoskeleton conformation. In this respect, and by day 7 in culture, significant increase in focal adhesion size was associated with the microstructured surfaces compared to the planar control. The morphological conformation of the seeded cells, as revealed by fluorescence cytoskeleton labelling, also appeared to be guided in the vertical dimension between the hemisphere bodies. Quantitative evaluation of this guidance took place using live cytoplasm fluorescence labelling and image morphometry analysis utilising both, compactness and elongation shape descriptors. Significant increase in cell compactness was associated with the hemisphere arrays indicating collective increase in focused cell attachment to the hemisphere bodies across the entire cell population. Micrometre-scale hemisphere array patterns have therefore influenced cell attachment and conformation. Such influence may potentially aid in enhancing key cellular events such as, for example, neo-osteogenesis on implanted orthopaedic surfaces.

Evaluation of TgH(CX3CR1-EGFP) mice implanted with mCherry-GL261 cells as an in vivo model for morphometrical analysis of glioma-microglia interaction.

PubMed

Resende, Fernando F B; Bai, Xianshu; Del Bel, Elaine Aparecida; Kirchhoff, Frank; Scheller, Anja; Titze-de-Almeida, Ricardo

2016-02-08

Glioblastoma multiforme is the most aggressive brain tumor. Microglia are prominent cells within glioma tissue and play important roles in tumor biology. This work presents an animal model designed for the study of microglial cell morphology in situ during gliomagenesis. It also allows a quantitative morphometrical analysis of microglial cells during their activation by glioma cells. The animal model associates the following cell types: 1- mCherry red fluorescent GL261 glioma cells and; 2- EGFP fluorescent microglia, present in the TgH(CX3CR1-EGFP) mouse line. First, mCherry-GL261 glioma cells were implanted in the brain cortex of TgH(CX3CR1-EGFP) mice. Epifluorescence - and confocal laser-scanning microscopy were employed for analysis of fixed tissue sections, whereas two-photon laser-scanning microscopy (2P-LSM) was used to track tumor cells and microglia in the brain of living animals. Implanted mCherry-GL261 cells successfully developed brain tumors. They mimic the aggressive behavior found in human disease, with a rapid increase in size and the presence of secondary tumors apart from the injection site. As tumor grows, mCherry-GL261 cells progressively lost their original shape, adopting a heterogeneous and diffuse morphology at 14-18 d. Soma size increased from 10-52 μm. At this point, we focused on the kinetics of microglial access to glioma tissues. 2P-LSM revealed an intense microgliosis in brain areas already shortly after tumor implantation, i.e. at 30 min. By confocal microscopy, we found clusters of microglial cells around the tumor mass in the first 3 days. Then cells infiltrated the tumor area, where they remained during all the time points studied, from 6-18 days. Microglia in contact with glioma cells also present changes in cell morphology, from a ramified to an amoeboid shape. Cell bodies enlarged from 366 ± 0.0 μm(2), in quiescent microglia, to 1310 ± 146.0 μm(2), and the cell processes became shortened. The GL261/CX3CR1 mouse model reported here is a valuable tool for imaging of microglial cells during glioma growth, either in fixed tissue sections or living animals. Remarkable advantages are the use of immunocompetent animals and the simplified imaging method without the need of immunohistochemical procedures.

Restoration of heart functions using human embryonic stem cells derived heart muscle cells.

PubMed

Gepstein, Lior; Kehat, Izhak

2005-02-01

Extract: Recent advances in molecular and cellular biology and specifically in the areas of stem cell biology and tissue engineering have paved the way for the development of a new field in biomedicine, regenerative medicine. This exciting approach seeks to develop new biological solutions, using the mobilization of endogenous stem cells or delivery of exogenous cells to replace or modify the function of diseased, absent, or malfunctioning tissue. The adult heart represents an attractive candidate for these emerging technologies, since adult cardiomyocytes have limited regenerative capacity. Thus, any significant heart cell loss or dysfunction, such as occurs during heart attack, is mostly irreversible and may lead to the development of progressive heart failure, one of the leading causes of world-wide morbidity and mortality. Similarly, dysfunction of the specialized electrical conduction system within the heart may result in inefficient rhythm initiation or impulse conduction, leading to significant slowing of the heart rate, usually requiring the implantation of a permanent electronic pacemaker. Replacement of the dysfunctional myocardium (heart muscle) by implantation of external heart muscle cells is emerging as a novel paradigm for restoration of the myocardial electromechanical properties, but has been significantly hampered by the paucity of cell sources for human heart cells and by the relatively limited evidence for functional integration between grafted and host cells. The recently described human embryonic stem cell (hESC) lines may provide a possible solution for the aforementioned cell sourcing problem.

Effects of bur wear during implant site preparation: an in vitro study.

PubMed

Scarano, A; Carinci, F; Quaranta, A; Di Iorio, D; Assenza, B; Piattelli, A

2007-01-01

Few studies have investigated the influence of drilling on bone healing. After the drilling of bone and placement of dental implants a sequence begins of cellular and molecular events which represents a combined response of wound healing. The bone healing around dental implants is a complex phenomenon and influences the proliferation and differentiation of pre-osteoblasts into osteoblasts, together with the activation of periosteal and endosteal lining cells, and initiates the production and mineralization of osteoid matrix followed by the organization of the bone-implant interface. The objective of this study is to quantify the temperature changes in cortical bone and marrow spaces during implant site preparation in bovine rib bone. A total 10 harvested bovine ribs and 6 10.5 x 3.5 new drills for implant insertion with external irrigation (Bone System, Milano, Italy) were used in this study. The implant sites were prepared with 10 mm long drills at 500 rpm under abundant external irrigation with saline solution at 37 degrees C. Each drill was used for 10, 30, 60, 90 and 120 implant site preparations; each drill was then observed under SEM for evaluation of the damage of the cutting edge after 10, 30, 60, 90 and 120 preparations. There was an higher and statistically significant increase in the temperature in the cortical bone; this increase in temperature increases with the number of the times of drill use. The drill wear seemed to play a major role in heat production and could explain the observed increased temperature of the bone.

Tissue-Engineered Heart Valve with a Tubular Leaflet Design for Minimally Invasive Transcatheter Implantation

PubMed Central

Moreira, Ricardo; Velz, Thaddaeus; Alves, Nuno; Gesche, Valentine N.; Malischewski, Axel; Schmitz-Rode, Thomas; Frese, Julia

2015-01-01

Transcatheter aortic valve implantation of (nonviable) bioprosthetic valves has been proven a valid alternative to conventional surgical implantation in patients at high or prohibitive mortality risk. In this study we present the in vitro proof-of-principle of a newly developed tissue-engineered heart valve for minimally invasive implantation, with the ultimate aim of adding the unique advantages of a living tissue with regeneration capabilities to the continuously developing transcatheter technologies. The tube-in-stent is a fibrin-based tissue-engineered valve with a tubular leaflet design. It consists of a tubular construct sewn into a self-expandable nitinol stent at three commissural attachment points and along a circumferential line so that it forms three coaptating leaflets by collapsing under diastolic back pressure. The tubular constructs were molded with fibrin and human umbilical vein cells. After 3 weeks of conditioning in a bioreactor, the valves were fully functional with unobstructed opening (systolic phase) and complete closure (diastolic phase). Tissue analysis showed a homogeneous cell distribution throughout the valve's thickness and deposition of collagen types I and III oriented along the longitudinal direction. Immunohistochemical staining against CD31 and scanning electron microscopy revealed a confluent endothelial cell layer on the surface of the valves. After harvesting, the valves underwent crimping for 20 min to simulate the catheter-based delivery. This procedure did not affect the valvular functionality in terms of orifice area during systole and complete closure during diastole. No influence on the extracellular matrix organization, as assessed by immunohistochemistry, nor on the mechanical properties was observed. These results show the potential of combining tissue engineering and minimally invasive implantation technology to obtain a living heart valve with a simple and robust tubular design for transcatheter delivery. The effect of the in vivo remodeling on the functionality of the tube-in-stent valve remains to be tested. PMID:25380414

In vitro fatigue tests and in silico finite element analysis of dental implants with different fixture/abutment joint types using computer-aided design models.

PubMed

Yamaguchi, Satoshi; Yamanishi, Yasufumi; Machado, Lucas S; Matsumoto, Shuji; Tovar, Nick; Coelho, Paulo G; Thompson, Van P; Imazato, Satoshi

2018-01-01

The aim of this study was to evaluate fatigue resistance of dental fixtures with two different fixture-abutment connections by in vitro fatigue testing and in silico three-dimensional finite element analysis (3D FEA) using original computer-aided design (CAD) models. Dental implant fixtures with external connection (EX) or internal connection (IN) abutments were fabricated from original CAD models using grade IV titanium and step-stress accelerated life testing was performed. Fatigue cycles and loads were assessed by Weibull analysis, and fatigue cracking was observed by micro-computed tomography and a stereomicroscope with high dynamic range software. Using the same CAD models, displacement vectors of implant components were also analyzed by 3D FEA. Angles of the fractured line occurring at fixture platforms in vitro and of displacement vectors corresponding to the fractured line in silico were compared by two-way ANOVA. Fatigue testing showed significantly greater reliability for IN than EX (p<0.001). Fatigue crack initiation was primarily observed at implant fixture platforms. FEA demonstrated that crack lines of both implant systems in vitro were observed in the same direction as displacement vectors of the implant fixtures in silico. In silico displacement vectors in the implant fixture are insightful for geometric development of dental implants to reduce complex interactions leading to fatigue failure. Copyright © 2017 Japan Prosthodontic Society. Published by Elsevier Ltd. All rights reserved.

A New Wnt1-CRE TomatoRosa Embryonic Stem Cell Line: A Tool for Studying Neural Crest Cell Integration Capacity.

PubMed

Acuna-Mendoza, Soledad; Martin, Sabrina; Kuchler-Bopp, Sabine; Ribes, Sandy; Thalgott, Jérémy; Chaussain, Catherine; Creuzet, Sophie; Lesot, Hervé; Lebrin, Franck; Poliard, Anne

2017-12-01

Neural crest (NC) cells are a migratory, multipotent population giving rise to numerous lineages in the embryo. Their plasticity renders attractive their use in tissue engineering-based therapies, but further knowledge on their in vivo behavior is required before clinical transfer may be envisioned. We here describe the isolation and characterization of a new mouse embryonic stem (ES) line derived from Wnt1-CRE-R26 Rosa TomatoTdv blastocyst and show that it displays the characteristics of typical ES cells. Further, these cells can be efficiently directed toward an NC stem cell-like phenotype as attested by concomitant expression of NC marker genes and Tomato fluorescence. As native NC progenitors, they are capable of differentiating toward typical derivative phenotypes and interacting with embryonic tissues to participate in the formation of neo-structures. Their specific fluorescence allows purification and tracking in vivo. This cellular tool should facilitate a better understanding of the mechanisms driving NC fate specification and help identify the key interactions developed within a tissue after in vivo implantation. Altogether, this novel model may provide important knowledge to optimize NC stem cell graft conditions, which are required for efficient tissue repair.

Spatiotemporal endothelial cell - pericyte association in tumors as shown by high resolution 4D intravital imaging.

PubMed

Seynhaeve, Ann L B; Oostinga, Douwe; van Haperen, Rien; Eilken, Hanna M; Adams, Susanne; Adams, Ralf H; Ten Hagen, Timo L M

2018-06-25

Endothelial cells and pericytes are integral cellular components of the vasculature with distinct interactive functionalities. To study dynamic interactions between these two cells we created two transgenic animal lines. A truncated eNOS (endothelial nitric oxide synthase) construct was used as a GFP tag for endothelial cell evaluation and an inducible Cre-lox recombination, under control of the Pdgfrb (platelet derived growth factor receptor beta) promoter, was created for pericyte assessment. Also, eNOStag-GFP animals were crossed with the already established Cspg4-DsRed mice expressing DsRed fluorescent protein in pericytes. For intravital imaging we used tumors implanted in the dorsal skinfold of these transgenic animals. This setup allowed us to study time and space dependent complexities, such as distribution, morphology, motility, and association between both vascular cell types in all angiogenetic stages, without the need for additional labeling. Moreover, as fluorescence was still clearly detectable after fixation, it is possible to perform comparative histology following intravital evaluation. These transgenic mouse lines form an excellent model to capture collective and individual cellular and subcellular endothelial cell - pericyte dynamics and will help answer key questions on the cellular and molecular relationship between these two cells.

Bone formation in vitro and in nude mice by human osteosarcoma cells.

PubMed

Ogose, A; Motoyama, T; Hotta, T; Watanabe, H; Takahashi, H E

1995-01-01

Osteosarcomas contain variable amounts of bony tissue, but the mechanism of bone formation by osteosarcoma is not well understood. While a number of cultured human osteosarcoma cell lines have been established, they are maintained by different media and differ qualitatively with regard to bone formation. We examined different media for their ability to support bone formation in vitro and found the alpha-modification of Eagle's minimal essential medium supplemented with beta glycerophosphate was best for this purpose, because it contained the proper calcium and phosphate concentrations. Subsequently, we compared seven human osteosarcoma cell lines under the same experimental conditions to clarify their ability to induce bone formation. NOS-1 cells most frequently exhibited features of bone formation in vitro and in nude mice. Collagen synthesis by tumour cells themselves seemed to be the most important factor for bone volume. However, even HuO9 cells, which lacked collagen synthesis and failed to form bone in vitro, successfully formed tumours containing bone in nude mice. Histological analysis of HuO9 cells in diffusion chambers implanted in nude mice and the findings of polymerase chain reaction indicated that the phenomenon was probably due to bone morphogenetic protein.

Simultaneous suppression of TGF-β and ERK signaling contributes to the highly efficient and reproducible generation of mouse embryonic stem cells from previously considered refractory and non-permissive strains.

PubMed

Hassani, Seyedeh-Nafiseh; Totonchi, Mehdi; Farrokhi, Ali; Taei, Adeleh; Larijani, Mehran Rezaei; Gourabi, Hamid; Baharvand, Hossein

2012-06-01

Mouse embryonic stem cells (ESCs) are pluripotent stem cell lines derived from pre-implantation embryos. The efficiency of mESC generation is affected by genetic variation in mice; that is, some mouse strains are refractory or non-permissive to ESC establishment. Developing an efficient method to derive mESCs from strains of various genetic backgrounds should be valuable for establishment of ESCs in various mammalian species. In the present study, we identified dual inhibition of TGF-β and ERK1/2, by SB431542 and PD0325901, respectively led to the highly efficient and reproducible generation of mESC lines from NMRI, C57BL/6, BALB/c, DBA/2, and FVB/N strains, which previously considered refractory or non-permissive for ESC establishment. These mESCs expressed pluripotency markers and retained the capacity to differentiate into derivatives of all three germ layers. The evaluated lines exhibited high rates of chimerism when reintroduced into blastocysts. To our knowledge, this is the first report of efficient (100%) mESC lines generation from different genetic backgrounds. The application of these two inhibitors will not only solve the problems of mESC derivation but also clarifies new signaling pathways in pluripotent mESCs.

Linguine sign at MR imaging: does it represent the collapsed silicone implant shell?

PubMed

Gorczyca, D P; DeBruhl, N D; Mund, D F; Bassett, L W

1994-05-01

One intact and one ruptured single-lumen implant were surgically placed in a rabbit. Magnetic resonance (MR) imaging was performed before and after surgical removal, and the ruptured implant was imaged after removal of the implant shell. Multiple curvilinear hypointense lines (linguine sign) were present in the MR images of the ruptured implant and of the implant shell alone immersed in saline solution but not in the image of the free silicone. The collapsed implant shell in a ruptured silicone implant does cause the linguine sign.

Biocompatibility and inflammatory response in vitro and in vivo to gelatin-based biomaterials with tailorable elastic properties.

PubMed

Ullm, Sandra; Krüger, Anne; Tondera, Christoph; Gebauer, Tim P; Neffe, Axel T; Lendlein, Andreas; Jung, Friedrich; Pietzsch, Jens

2014-12-01

Hydrogels prepared from gelatin and lysine diisocyanate ethyl ester provide tailorable elastic properties and degradation behavior. Their interaction with human aortic endothelial cells (HAEC) as well as human macrophages (Mɸ) and granulocytes (Gɸ) were explored. The experiments revealed a good biocompatibility, appropriate cell adhesion, and cell infiltration. Direct contact to hydrogels, but not contact to hydrolytic or enzymatic hydrogel degradation products, resulted in enhanced cyclooxygenase-2 (COX-2) expression in all cell types, indicating a weak inflammatory activation in vitro. Only Mɸ altered their cytokine secretion profile after direct hydrogel contact, indicating a comparably pronounced inflammatory activation. On the other hand, in HAEC the expression of tight junction proteins, as well as cytokine and matrix metalloproteinase secretion were not influenced by the hydrogels, suggesting a maintained endothelial cell function. This was in line with the finding that in HAEC increased thrombomodulin synthesis but no thrombomodulin membrane shedding occurred. First in vivo data obtained after subcutaneous implantation of the materials in immunocompetent mice revealed good integration of implants in the surrounding tissue, no progredient fibrous capsule formation, and no inflammatory tissue reaction in vivo. Overall, the study demonstrates the potential of gelatin-based hydrogels for temporal replacement and functional regeneration of damaged soft tissue. Copyright © 2014 Elsevier Ltd. All rights reserved.

Effect of C-implantation on Nerve-Cell Attachment to Polystyrene Films

NASA Astrophysics Data System (ADS)

Sommani, Piyanuch; Tsuji, Hiroshi; Kitamura, Tsuyoshi; Hattori, Mitsutaka; Yamada, Tetsuya; Sato, Hiroko; Gotoh, Yasuhito; Ishikawa, Junzo

The surfaces of the polystyrene films spin-coated on glass were modified by carbon negative-ion implantation with various ion doses from 1×1014 to 3×1016 ions/cm2 at 5 and 10 keV. The implantation conditions with and without a pattering mask were for investigation of the cell-attachment properties and for evaluation of surface physical properties of contact angle, respectively. The contact angles of modified surface were investigated by pure water drop and air bubble method. The lowest angle value of the implanted films at 5 and 10 keV were approximately 72° at 3×1015 ions/cm2 after dipping in the de-ionized water for 2 hours. The lowering of contact angles on C-implanted surfaces when increase the ion dose is due to formation of the OH and C-O bonds. Nerve-cell-attachment properties of modified surface were investigated by the nerve-like cell of rat adrenal pheochromocytoma (PC12h) in vitro. After 2 days culture of the PC12h cells, no cells attached on the polystyrene films implanted with low ion dose from 1×1014 to 3×1014 ions/cm2. On the polystyrene films implanted with the dose order of 1015 ions/cm2, the cells selectively attached only on the implanted region. Whereas on the surfaces implanted with high dose such as 1×1016 and 3×1016 ions/cm2 mostly cells attached on the implanted region, and some attached on the unimplanted region, as well as cells were abnormal in shape and large size. Therefore, the suitable dose implantation for the selective-attachment of nerve-cells on the polystyrene films implanted at 5 and 10 keV were obtained around the dose order of 1015 ions/cm2, and the best condition for the selective attachment properties was at 3×1015 ions/cm2 corresponding to the lowest contact angle.

Syndecan-1 knock-down in decidualized human endometrial stromal cells leads to significant changes in cytokine and angiogenic factor expression patterns

PubMed Central

2010-01-01

Background Successful embryonic implantation depends on a synchronized embryo-maternal dialogue. Chemokines, such as chemokine ligand 1 (CXCL1), play essential roles in the maternal reproductive tract leading to morphological changes during decidualization, mediating maternal acceptance towards the semi-allograft embryo and induction of angiogenesis. Chemokine binding to their classical G-protein coupled receptors is essentially supported by the syndecan (Sdc) family of heparan sulfate proteoglycans. The aim of this study was to identify the involvement of Sdc-1 at the embryo-maternal interface regarding changes of the chemokine and angiogenic profile of the decidua during the process of decidualization and implantation in human endometrium. Methods A stable Sdc-1 knock-down was generated in the immortalized human endometrial stromal cell line St-T1 and was named KdS1. The ability of KdS1 to decidualize was proven by Insulin-like growth factor binding 1 (IGFBP1) and prolactin (PRL) confirmation on mRNA level before further experiments were carried out. Dot blot protein analyses of decidualized knock-down cells vs non-transfected controls were performed. In order to imitate embryonic implantation, decidualized KdS1 were then incubated with IL-1beta, an embryo secretion product, vs controls. Statistical analyses were performed applying the Student's t-test with p < 0.05, p < 0.02 and p < 0.01 and one way post-hoc ANOVA test with p < 0.05 as cut-offs for statistical significance. Results The induction of the Sdc-1 knock-down revealed significant changes in cytokine and angiogenic factor expression profiles of dKdS1 vs decidualized controls. Incubation with embryonic IL-1beta altered the expression patterns of KdS1 chemokines and angiogenic factors towards inflammatory-associated molecules and factors involved in matrix regulation. Conclusions Sdc-1 knock-down in human endometrial stroma cells led to fulminant changes regarding cytokine and angiogenic factor expression profiles upon decidualization and imitation of embryonic contact. Sdc-1 appears to play an important role as a co-receptor and storage factor for many cytokines and angiogenic factors during decidualization and implantation period, supporting proper implantation and angiogenesis by regulation of chemokine and angiogenic factor secretion in favour of the implanting embryo. PMID:21044331

Pulp Cell Tracking by Radionuclide Imaging for Dental Tissue Engineering

PubMed Central

Souron, Jean-Baptiste; Petiet, Anne; Decup, Franck; Tran, Xuan Vinh; Lesieur, Julie; Poliard, Anne; Le Guludec, Dominique; Letourneur, Didier; Chaussain, Catherine; Rouzet, Francois

2014-01-01

Pulp engineering with dental mesenchymal stem cells is a promising therapy for injured teeth. An important point is to determine the fate of implanted cells in the pulp over time and particularly during the early phase following implantation. Indeed, the potential engraftment of the implanted cells in other organs has to be assessed, in particular, to evaluate the risk of inducing ectopic mineralization. In this study, our aim was to follow by nuclear imaging the radiolabeled pulp cells after implantation in the rat emptied pulp chamber. For that purpose, indium-111-oxine (111In-oxine)-labeled rat pulp cells were added to polymerizing type I collagen hydrogel to obtain a pulp equivalent. This scaffold was implanted in the emptied pulp chamber space in the upper first rat molar. Labeled cells were then tracked during 3 weeks by helical single-photon emission computed tomography (SPECT)/computed tomography performed on a dual modality dedicated small animal camera. Negative controls were performed using lysed radiolabeled cells obtained in a hypotonic solution. In vitro data indicated that 111In-oxine labeling did not affect cell viability and proliferation. In vivo experiments allowed a noninvasive longitudinal follow-up of implanted living cells for at least 3 weeks and indicated that SPECT signal intensity was related to implanted cell integrity. Notably, there was no detectable systemic release of implanted cells from the tooth. In addition, histological analysis of the samples showed mitotically active fibroblastic cells as well as neoangiogenesis and nervous fibers in pulp equivalents seeded with entire cells, whereas pulp equivalents prepared from lysed cells were devoid of cell colonization. In conclusion, our study demonstrates that efficient labeling of pulp cells can be achieved and, for the first time, that these cells can be followed up after implantation in the tooth by nuclear imaging. Furthermore, it appears that grafted cells retained the label and are viable to follow the repair process. This technique is expected to be of major interest for monitoring implanted cells in innovative therapies for injured teeth. PMID:23789732

Effect of implant angulation and impression technique on impressions of NobelActive implants.

PubMed

Alexander Hazboun, Gillian Brewer; Masri, Radi; Romberg, Elaine; Kempler, Joanna; Driscoll, Carl F

2015-05-01

How the configuration of the NobelActive internal conical connection affects implant impressions is uncertain. The purpose of this study was to measure the effect in vitro of closed and open tray impression techniques for NobelActive implants placed at various angulations. Six NobelActive implants were placed in a master maxillary cast as follows: 0 degrees of angulation to a line drawn perpendicular to the occlusal plane in the first molar area, 15 degrees of angulation to a line drawn perpendicular to the occlusal plane in the first premolar area, and 30 degrees of angulation to a line drawn perpendicular to the occlusal plane in the lateral incisor area. Twelve open tray and 12 closed tray impressions were made. Occlusal, lateral, and frontal view photographs of the resulting casts were used to measure the linear and angular displacement of implant analogs. Statistical analysis was performed with a factorial analysis of variance (ANOVA), followed by the Tukey HSD test (α=.05). No significant difference was found in the impressions made of NobelActive implants with the open or closed tray technique (linear displacement: F=0.93, P=.34; angular displacement: F=2.09, P=.15). In addition, implant angulation (0, 15, or 30 degrees) had no effect on the linear or angular displacement of impressions (linear displacement: F=2.72, P=.07; angular displacement: F=0.86, P=.43). Finally, no significant interaction was found between impression technique and implant angulation on NobelActive implants (F=0.25, P=.77; F=1.60, P=.20). Within the limitations of this study, impression technique (open vs closed tray) and implant angulation (0, 15, and 30 degrees) had no significant effect on in vitro impressions of NobelActive implants. Copyright © 2015 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

Treatment of peri-implant diseases: a review of the literature and protocol proposal.

PubMed

Armas, Joshé; Culshaw, Shauna; Savarrio, Lee

2013-01-01

Over 100,000 implants were placed in the UK in 2010. As the numbers of patients with implant-retained prostheses increases, operators are encountering an increasing number of biological implant complications, most commonly peri-implant mucositis and peri-implantitis. The effective management of these complications is crucial to maintain patients' oral health. In particular, in contrast to common periodontal infections, some peri-implant infections may benefit from surgical intervention as a first line approach. This article reviews the literature on the treatment options for peri-implant mucositis and peri-implantitis and proposes a protocol for their treatment.

Impella 5.0 as a Second-Line Mechanical Circulatory Support Strategy After Extracorporeal Life Support.

PubMed

Schibilsky, David; Kruger, Tobias; Lausberg, Henning F; Eisenlohr, Christoph; Haller, Christoph; Nemeth, Attila; Schibilsky, Barbara; Haeberle, Helene; Rosenberger, Peter; Walker, Tobias; Schlensak, Christian

2016-09-01

The catheter-based Impella 5.0 left ventricular assist device is a powerful and less invasive alternative for patients in cardiogenic shock. The use as second-line therapy in patients with precedent extracorporeal life support (ECLS) has not been described before now. We analyzed our experience of consecutive patients treated with this alternative strategy. From April 2014 to December 2014, eight patients had been implanted as a second-line option after ECLS support. The reason for the change from ECLS to Impella 5.0 was absence of cardiac recovery for primary weaning and complications of ECLS therapy. The mean time of ECLS support prior to Impella implantation was 12 ± 7 days. The implantation of the Impella 5.0/CP was technically successful in all patients, and the ECLS could be explanted in all eight patients who received Impella implantation as a second-line treatment. The second-line Impella 5.0 therapy resulted in two patients who turned into left ventricular assist device (LVAD) candidates, two primary weaning candidates, and four patients who died in the setting of sepsis or absent cardiac recovery and contraindications for durable LVAD therapy. Thereby, the overall hospital discharge survival as well as the 180-day survival was 50% for Impella 5.0 implantations as second-line procedure after ECLS. The latest follow-up survival of this second-line strategy after ECLS was three out of eight, as one patient died after 299 days of LVAD support due to sepsis. The use of Impella 5.0 constitutes a possible second-line therapeutic option for those patients who do not show cardiac recovery during prolonged ECLS support or suffer from complications of ECLS therapy. This treatment allows additional time for decisions regarding cardiac recovery or indication for durable LVAD therapy. © 2016 International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

Use of low-energy hydrogen ion implants in high-efficiency crystalline-silicon solar cells

NASA Technical Reports Server (NTRS)

Fonash, S. J.; Sigh, R.; Mu, H. C.

1986-01-01

The use of low-energy hydrogen implants in the fabrication of high-efficiency crystalline silicon solar cells was investigated. Low-energy hydrogen implants result in hydrogen-caused effects in all three regions of a solar cell: emitter, space charge region, and base. In web, Czochralski (Cz), and floating zone (Fz) material, low-energy hydrogen implants reduced surface recombination velocity. In all three, the implants passivated the space charge region recombination centers. It was established that hydrogen implants can alter the diffusion properties of ion-implanted boron in silicon, but not ion-implated arsenic.

Anaplastic large cell lymphoma and breast implants: five Australian cases.

PubMed

Taylor, Kim O; Webster, Howard R; Prince, H Miles

2012-04-01

There has never been a convincing association between breast implants and breast malignancy. A total of 42 cases of non-Hodgkin's lymphoma of the breast associated with implant capsules have been reported. The majority of the patients have anaplastic large cell lymphoma of T-cell origin. These lymphoma types have less frequently been observed in women without implants. The senior author (H.R.W.) diagnosed and treated two women with anaplastic large cell lymphoma in a short period of time. After this, the authors were contacted by other surgeons in Australia who had treated similar cases. The authors report five new cases of anaplastic large cell lymphoma associated with breast implants. There is an apparent spectrum of disease, with some cases pursuing an aggressive clinical course, although most have experienced a good prognosis. Both saline and silicone implants are implicated. All implant shells were textured. Textured surface implants only became widely used in the 1990s and therefore were not significantly represented in the large cohort studies of breast implant safety undertaken in the early 1990s. The diagnosis of anaplastic large cell lymphoma in the breast needs to be considered in patients, particularly those presenting with a periprosthetic seroma 6 months or more after breast implant insertion. Risk, V.

A Biosynthetic Nerve Guide Conduit Based on Silk/SWNT/Fibronectin Nanocomposite for Peripheral Nerve Regeneration

PubMed Central

Mottaghitalab, Fatemeh; Farokhi, Mehdi; Zaminy, Arash; Kokabi, Mehrdad; Soleimani, Masoud; Mirahmadi, Fereshteh

2013-01-01

As a contribution to the functionality of nerve guide conduits (NGCs) in nerve tissue engineering, here we report a conduit processing technique through introduction and evaluation of topographical, physical and chemical cues. Porous structure of NGCs based on freeze-dried silk/single walled carbon nanotubes (SF/SWNTs) has shown a uniform chemical and physical structure with suitable electrical conductivity. Moreover, fibronectin (FN) containing nanofibers within the structure of SF/SWNT conduits produced through electrospinning process have shown aligned fashion with appropriate porosity and diameter. Moreover, fibronectin remained its bioactivity and influenced the adhesion and growth of U373 cell lines. The conduits were then implanted to 10 mm left sciatic nerve defects in rats. The histological assessment has shown that nerve regeneration has taken places in proximal region of implanted nerve after 5 weeks following surgery. Furthermore, nerve conduction velocities (NCV) and more myelinated axons were observed in SF/SWNT and SF/SWNT/FN groups after 5 weeks post implantation, indicating a functional recovery for the injured nerves. With immunohistochemistry, the higher S-100 expression of Schwann cells in SF/SWNT/FN conduits in comparison to other groups was confirmed. In conclusion, an oriented conduit of biocompatible SF/SWNT/FN has been fabricated with acceptable structure that is particularly applicable in nerve grafts. PMID:24098649

Sustained release vancomycin-coated titanium alloy using a novel electrostatic dry powder coating technique may be a potential strategy to reduce implant-related infection.

PubMed

Han, Jing; Yang, Yi; Lu, Junren; Wang, Chenzhong; Xie, Youtao; Zheng, Xuebin; Yao, Zhenjun; Zhang, Chi

2017-07-24

In order to tackle the implant-related infection, a novel way was developed in this study to coat vancomycin particles mixed with controlled release coating materials onto the surface of titanium alloy by using an electrostatic dry powder coating technique. To characterize this sustained release antibacterial coating, surface morphology, in vitro and in vivo drug release were sequentially evaluated. In vitro cytotoxicity was tested by Cell Counting Kit-8 (CCK-8) assay and cytological changes were observed by inverted microscope. The antibacterial properties against MRSA, including a bacterial growth inhibition assay and a colony-counting test by spread plate method were performed. Results indicated that the vancomycin-coated sample was biocompatible for Human osteoblast cell line MG-63 and displayed effective antibacterial ability against MRSA. The coating film was revealed uniform by scanning electron microscopy. Both the in vitro and in vivo drug release kinetics showed an initially high release rate, followed by an extended period of sustained drug release over 7 days. These results suggest that with good biocompatibility and antibacterial ability, the sustained release antibacterial coating of titanium alloy using our novel electrostatic dry powder coating process may provide a promising candidate for the treatment of orthopedic implant-related infection.

Femtosecond laser induced surface modification for prevention of bacterial adhesion on 45S5 bioactive glass

NASA Astrophysics Data System (ADS)

Shaikh, Shazia; Singh, Deepti; Subramanian, Mahesh; Kedia, Sunita; Singh, Anil Kumar; Singh, Kulwant; Gupta, Nidhi; Sinha, Sucharita

2018-02-01

Bacterial attachment and biofilm formation on implant surface has been a major concern in hospital and industrial environment. Prevention of bacterial infections of implant surface through surface treatment could be a potential solution and hence this has become a key area of research. In the present study, the antibacterial and biocompatible properties of femtosecond laser surface treated 45S5 bioactive glass (BG) have been investigated. Adhesion and sustainability of both gram positive S. aureus and gram negative P.aeruginosa and E. coli nosocomial bacteria on untreated and laser treated BG samples has been explored. An imprint method has been used to visualize the growth of bacteria on the sample surface. We observed complete bacterial rejection potentially reducing risk of biofilm formation on laser treated surface. This was correlated with surface roughness, wettability and change in surface chemical composition of the samples before and after laser treatment. Biocompatibility of the laser treated BG was demonstrated by studying the anchoring and growth of human cervix cell line INT407. Our results demonstrate that, laser surface modification of BG enables enhanced bacterial rejection without affecting its biocompatibility towards growth of human cells on it. These results open a significantly potential approach towards use of laser in successfully imparting desirable characteristics to BG based bio-implants and devices.

Effects of delayed treatment with combined GDNF and continuous electrical stimulation on spiral ganglion cell survival in deafened guinea pigs.

PubMed

Scheper, Verena; Paasche, Gerrit; Miller, Josef M; Warnecke, Athanasia; Berkingali, Nurdanat; Lenarz, Thomas; Stöver, Timo

2009-05-01

Electrical stimulation (ES) of spiral ganglion cells (SGC) via a cochlear implant is the standard treatment for profound sensor neural hearing loss. However, loss of hair cells as the morphological correlate of sensor neural hearing loss leads to deafferentation and death of SGC. Although immediate treatment with ES or glial cell line-derived neurotrophic factor (GDNF) can prevent degeneration of SGC, only few studies address the effectiveness of delayed treatment. We hypothesize that both interventions have a synergistic effect and that even delayed treatment would protect SGC. Therefore, an electrode connected to a pump was implanted into the left cochlea of guinea pigs 3 weeks after deafening. The contralateral untreated cochleae served as deafened intraindividual controls. Four groups were set up. Control animals received intracochlear infusion of artificial perilymph (AP/-). The experimental groups consisted of animals treated with AP in addition to continuous ES (AP/ES) or treated with GDNF alone (GDNF/-) or GDNF combined with continuous ES (GDNF/ES). Acoustically and electrically evoked auditory brain stem responses were recorded. All animals were killed 48 days after deafening; their cochleae were histologically evaluated. Survival of SGC increased significantly in the GDNF/- and AP/ES group compared with the AP/- group. A highly significant increase in SGC density was observed in the GDNF/ES group compared with the control group. Additionally, animals in the GDNF/ES group showed reduced EABR thresholds. Thus, delayed treatment with GDNF and ES can protect SGC from degeneration and may improve the benefits of cochlear implants.

3-bromopyruvate enhanced daunorubicin-induced cytotoxicity involved in monocarboxylate transporter 1 in breast cancer cells.

PubMed

Liu, Zhe; Sun, Yiming; Hong, Haiyu; Zhao, Surong; Zou, Xue; Ma, Renqiang; Jiang, Chenchen; Wang, Zhiwei; Li, Huabin; Liu, Hao

2015-01-01

Increasing evidence demonstrates that the hexokinase inhibitor 3-bromopyruvate (3-BrPA) induces the cell apoptotic death by inhibiting ATP generation in human cancer cells. Interestingly, some tumor cell lines are less sensitive to 3-BrPA-induced apoptosis than others. Moreover, the molecular mechanism of 3-BrPA-trigged apoptosis is unclear. In the present study, we examined the effects of 3-BrPA on the viability of the breast cancer cell lines MDA-MB-231 and MCF-7. We further investigated the potential roles of monocarboxylate transporter 1 (MCT1) in drug accumulation and efflux of breast cancer cells. Finally, we explored whether 3-BrPA enhanced daunorubicin (DNR)-induced cytotoxicity through regulation of MCT1 in breast cancer cells. MTT and colony formation assays were used to measure cell viability. Western blot analysis, flow cytometric analysis and fluorescent microscopy were used to determine the molecular mechanism of actions of MCT1 in different breast cancer cell lines. Whole-body bioluminescence imaging was used to investigate the effect of 3-BrPA in vivo. We found that 3-BrPA significantly inhibited cell growth and induced apoptosis in MCF-7 cell line, but not in MDA-MB-231 cells. Moreover, we observed that 3-BrPA efficiently enhanced DNR-induced cytotoxicity in MCF-7 cells by inhibiting the activity of ATP-dependent efflux pumps. We also found that MCT1 overexpression increased the efficacy of 3-BrPA in MDA-MB-231 cells. 3-BrPA markedly suppressed subcutaneous tumor growth in combination with DNR in nude mice implanted with MCF-7 cells. Lastly, our whole-body bioluminescence imaging data indicated that 3-BrPA promoted DNR accumulation in tumors. These findings collectively suggest that 3-BrPA enhanced DNR antitumor activity in breast cancer cells involved MCT-1, suggesting that inhibition of glycolysis could be an effective therapeutic approach for breast cancer treatment.

Hepa1-6-FLuc cell line with the stable expression of firefly luciferase retains its primary properties with promising bioluminescence imaging ability.

PubMed

Li, Yasha; Liu, Mengnan; Cui, Jiejie; Yang, Ke; Zhao, Li; Gong, Mengjia; Wang, Yi; He, Yun; He, Tongchuan; Bi, Yang

2018-05-01

Reliable animal models are required for the in vivo study of the molecular mechanisms and effects of chemotherapeutic drugs in hepatocarcinoma. In vivo tracing techniques based on firefly luciferase (FLuc) may optimize the non-invasive monitoring of experimental animals. The present study established a murine Hepa1-6-FLuc cell line that stably expressed a retrovirus-delivered FLuc protein gene. The cell morphology, proliferation, migration and invasion ability of Hepa1-6-FLuc cells were the same as that of the Hepa1-6 cells, and thus is suitable to replace Hepa1-6 cells in the construction of hepatocarcinoma animal models. No differences in subcutaneous tumor mass and its pathomorphology from implanted Hepa1-6-FLuc cells were observed compared with Hepa1-6 control tumors. Bioluminescence imaging indicated that the Luc signal of the Hepa1-6-FLuc cells was consistently strengthened with increases in tumor mass; however, the Luc signal of Hepa1-6-AdFLuc became weaker and eventually disappeared during tumor development. Therefore, compared with the transient expression by adenovirus, stable expression of the FLuc gene in Hepa1-6 cells may better reflect cell proliferation and survival in vivo , and provide a reliable source for the establishment of hepatocarcinoma models.

In Vivo Assessment of Printed Microvasculature in a Bilayer Skin Graft to Treat Full-Thickness Wounds

PubMed Central

Yanez, Maria; Rincon, Julio; Dones, Aracely; De Maria, Carmelo; Gonzales, Raoul

2015-01-01

Chronic wounds such as diabetic foot ulcers and venous leg ulcers are common problems in people suffering from type 2 diabetes. These can cause pain, and nerve damage, eventually leading to foot or leg amputation. These types of wounds are very difficult to treat and sometimes take months or even years to heal because of many possible complications during the process. Allogeneic skin grafting has been used to improve wound healing, but the majority of grafts do not survive several days after being implanted. We have been studying the behavior of fibroblasts and keratinocytes in engineered capillary-like endothelial networks. A dermo-epidermal graft has been implanted in an athymic nude mouse model to assess the integration with the host tissue as well as the wound healing process. To build these networks into a skin graft, a modified inkjet printer was used, which allowed the deposit of human microvascular endothelial cells. Neonatal human dermal fibroblast cells and neonatal human epidermal keratinocytes were manually mixed in the collagen matrix while endothelial cells printed. A full-thickness wound was created at the top of the back of athymic nude mice and the area was covered by the bilayered graft. Mice of the different groups were followed until completion of the specified experimental time line, at which time the animals were humanely euthanized and tissue samples were collected. Wound contraction improved by up to 10% when compared with the control groups. Histological analysis showed the neoskin having similar appearance to the normal skin. Both layers, dermis and epidermis, were present with thicknesses resembling normal skin. Immunohistochemistry analysis showed favorable results proving survival of the implanted cells, and confocal images showed the human cells' location in the samples that were collocated with the bilayer printed skin graft. PMID:25051339

In vivo assessment of printed microvasculature in a bilayer skin graft to treat full-thickness wounds.

PubMed

Yanez, Maria; Rincon, Julio; Dones, Aracely; De Maria, Carmelo; Gonzales, Raoul; Boland, Thomas

2015-01-01

Chronic wounds such as diabetic foot ulcers and venous leg ulcers are common problems in people suffering from type 2 diabetes. These can cause pain, and nerve damage, eventually leading to foot or leg amputation. These types of wounds are very difficult to treat and sometimes take months or even years to heal because of many possible complications during the process. Allogeneic skin grafting has been used to improve wound healing, but the majority of grafts do not survive several days after being implanted. We have been studying the behavior of fibroblasts and keratinocytes in engineered capillary-like endothelial networks. A dermo-epidermal graft has been implanted in an athymic nude mouse model to assess the integration with the host tissue as well as the wound healing process. To build these networks into a skin graft, a modified inkjet printer was used, which allowed the deposit of human microvascular endothelial cells. Neonatal human dermal fibroblast cells and neonatal human epidermal keratinocytes were manually mixed in the collagen matrix while endothelial cells printed. A full-thickness wound was created at the top of the back of athymic nude mice and the area was covered by the bilayered graft. Mice of the different groups were followed until completion of the specified experimental time line, at which time the animals were humanely euthanized and tissue samples were collected. Wound contraction improved by up to 10% when compared with the control groups. Histological analysis showed the neoskin having similar appearance to the normal skin. Both layers, dermis and epidermis, were present with thicknesses resembling normal skin. Immunohistochemistry analysis showed favorable results proving survival of the implanted cells, and confocal images showed the human cells' location in the samples that were collocated with the bilayer printed skin graft.

In vitro and in vivo characterization of anodised zirconium as a potential material for biomedical applications.

PubMed

Katunar, Maria R; Gomez Sanchez, Andrea; Santos Coquillat, Ana; Civantos, Ana; Martinez Campos, Enrique; Ballarre, Josefina; Vico, Tamara; Baca, Matias; Ramos, Viviana; Cere, Silvia

2017-06-01

In vitro studies offer the insights for the understanding of the mechanisms at the tissue-implant interface that will provide an effective functioning in vivo. The good biocompatibility of zirconium makes a good candidate for biomedical applications and the attractive in vivo performance is mainly due to the presence of a protective oxide layer. The aim of this study is to evaluate by in vitro and in vivo approach, the influence of surface modification achieved by anodisation at 30 and 60V on zirconium implants on the first steps of the osseointegration process. In this study cell attachment, proliferation and morphology of mouse myoblast C2C12-GFP and in mouse osteoprogenitor MC3T3-E1 cells was evaluated. Also, together with the immune system response, osteoclast differentiation and morphology with RAW 264.7 murine cell line were analysed. It was found that anodisation treatment at 60V enhanced cell spreading and the osteoblastic and osteoclastic cells morphology, showing a strong dependence on the surface characteristics. In vivo tests were performed in a rat femur osteotomy model. Dynamical and static histological and histomorphometric analyses were developed 15 and 30days after surgery. Newly formed bone around Zr60V implants showed a continuous newly compact and homogeneous bone just 15 after surgery, as judged by the enhanced thickness and mineralization rate. The results indicate that anodising treatment at 60V could be an effective improvement in the osseointegration of zirconium by stimulating adhesion, proliferation, morphology, new bone thickness and bone mineral apposition, making zirconium an emerging candidate material for biomedical applications. Copyright © 2017 Elsevier B.V. All rights reserved.

Electronic structure of ytterbium-implanted GaN at ambient and high pressure: experimental and crystal field studies.

PubMed

Kaminska, A; Ma, C-G; Brik, M G; Kozanecki, A; Boćkowski, M; Alves, E; Suchocki, A

2012-03-07

The results of high-pressure low-temperature optical measurements in a diamond-anvil cell of bulk gallium nitride crystals implanted with ytterbium are reported in combination with crystal field calculations of the Yb(3+) energy levels. Crystal field analysis of splitting of the (2)F(7/2) and (2)F(5/2) states has been performed, with the aim of assigning all features of the experimental luminescence spectra. A thorough analysis of the pressure behavior of the Yb(3+) luminescence lines in GaN allowed the determination of the ambient-pressure positions and pressure dependence of the Yb(3+) energy levels in the trigonal crystal field as well as the pressure-induced changes of the spin-orbit coupling coefficient.

Development of pulsed processes for the manufacture of solar cells

NASA Technical Reports Server (NTRS)

Minnucci, J. A.

1978-01-01

The results of a 1-year program to develop the processes required for low-energy ion implantation for the automated production of silicon solar cells are described. The program included: (1) demonstrating state-of-the-art ion implantation equipment and designing an automated ion implanter, (2) making efforts to improve the performance of ion-implanted solar cells to 16.5 percent AM1, (3) developing a model of the pulse annealing process used in solar cell production, and (4) preparing an economic analysis of the process costs of ion implantation.

Alternative site of implantation affects tumor malignancy and metastatic potential in mice: its comparison to the flank model.

PubMed

Speroni, Lucia; Bustuoabad, Victoria de Los Angeles; Gasparri, Julieta; Chiaramoni, Nadia Silvia; Taira, María Cristina; Ruggiero, Raúl Alejandro; Alonso, Silvia Del Valle

2009-02-01

MC-C fibrosarcoma and B16F0 melanoma tumors were implanted intradermally in the dorsal region of the foot of mice. Tumor progression was compared to standard implantation in the flank. Although foot tumors only reached 13% (MC-C) and 25% (B16F0) of the mean volume of flank tumors, a more malignant phenotype in terms of histology and survival rate was observed in this type of tumors. Moreover, lung metastases were only detected in hosts bearing foot tumors, in contrast to MC-C and B16F0 populations with tumors growing in the flank. In addition, cellular influx and local immune reaction were higher in the dorsal region of the foot. According to our results, the dermis of the flank allows excessive tumor growth due to its low reactivity. Thus, differences in innate and adaptive immune effectors between the evaluated tumor microenvironments would account for the differences in tumor malignancy. Due to its striking differences with the standard flank inoculation, the tumor implantation model herein introduced could be a valuable tool to study the metastatic potential of different cell lines and the microenvironment components affecting tumor growth.

Effect of sustained gene delivery of platelet-derived growth factor or its antagonist (PDGF-1308) on tissue-engineered cementum.

PubMed

Anusaksathien, Orasa; Jin, Qiming; Zhao, Ming; Somerman, Martha J; Giannobile, William V

2004-03-01

Cementum, a mineralized tissue lining the tooth root surface, is destroyed during the inflammatory process of periodontitis. Restoration of functional cementum is considered a criterion for successful regeneration of periodontal tissues, including formation of periodontal ligament, cementum, and alveolar bone. Short-term administration of platelet-derived growth factor (PDGF) has been shown to partially regenerate periodontal structures. Nonetheless, the role of PDGF in cementogenesis is not well understood. The aim of the present study was to determine the effect of sustained PDGF gene transfer on cementum formation in an ex vivo ectopic biomineralization model. Osteocalcin (OC) promoter-driven SV40 transgenic mice were used to obtain immortalized cementoblasts (OCCM). The OCCM cells were transduced with adenoviruses (Ad) encoding either PDGF-A, an antagonist of PDGF signaling (PDGF-1308), a control virus (green fluorescent protein, GFP), or no treatment (NT). The transduced cells were incorporated into polymer scaffolds and implanted subcutaneously into severe combined immunodeficient (SCID) mice. The implants were harvested at 3 and 6 weeks for histomorphometric analysis of the newly formed mineralized tissues. Northern blot analysis was performed to determine the expression levels of mineral-associated genes including bone sialoprotein (BSP), OC, and osteopontin (OPN) in the cell-implant specimens at 3 and 6 weeks. The results indicated mineralization was significantly reduced in both the Ad/PDGF-A and Ad/PDGF-1308 treated specimens when compared to the NT or Ad/GFP groups at 3 and 6 weeks (P<0.01). In addition, the size of the implants treated with Ad/PDGF-A and Ad/PDGF-1308 was significantly reduced compared to implants from Ad/GFP and NT groups at 3 weeks (P<0.05). At 6 weeks, the size of implants and mineral formation increased in NT, Ad/GFP, and Ad/PDGF-A groups, while the Ad/PDGF-1308 treated implants continued to decrease in size and mineral formation (P<0.01). Northern blot analysis revealed that in the Ad/PDGF-A treated implants OPN was increased, whereas OC gene expression was downregulated at 3 weeks. In the Ad/PDGF-1308 treated implants, BSP, OC, and OPN were all downregulated at 3 weeks. At 3 weeks, the Ad/PDGF-A treated implants contained significantly higher multinucleated giant cell (MNGC) density compared to NT, Ad/GFP, and Ad/PDGF-1308 specimens. The MNGC density in NT, Ad/GFP, and Ad/PDGF-A treated groups reduced over time, while the Ad/PDGF-1308 transduced implants continued to exhibit significantly higher MNGC density compared with the other treatment groups at 6 weeks. The results showed that continuous exposure to PDGF-A had an inhibitory effect on cementogenesis, possibly via the upregulation of OPN and subsequent enhancement of MNGCs at 3 weeks. On the other hand, Ad/PDGF-1308 inhibited mineralization of tissue-engineered cementum possibly due to the observed downregulation of BSP and OC and a persistence of stimulation of MNGCs. These findings suggest that continuous exogenous delivery of PDGF-A may delay mineral formation induced by cementoblasts, while PDGF is clearly required for mineral neogenesis.

Possible involvement of persistent activity of the mammalian target of rapamycin pathway in the cisplatin resistance of AFP-producing gastric cancer cells.

PubMed

Kamata, Shigeyuki; Kishimoto, Takashi; Kobayashi, Soichi; Miyazaki, Masaru; Ishikura, Hiroshi

2007-07-01

AFP-producing gastric carcinoma (AFPGC) is a highly malignant variant of gastric cancer. An effective chemotherapy is needed to improve on the poor outcome of this disease. Survival signals activated by intracellular kinase networks could be involved in chemoresistance in malignant tumors. We investigated the role of a pivotal kinase pathway, the mammalian target of rapamycin complex 1 (mTORC1) pathway, in the effectiveness of chemotherapeutic agents in three AFPGC cell lines (GCIY, FU97 and Takigawa) as well as in four cell lines of conventional-type gastric carcinoma (CGC). AFPGC cells were generally resistant to multiple chemotherapeutic agents, including cisplatin, while CGC cells were generally sensitive. Downstream targets of mTORC1, including p70S6K and 4EBP1, were phosphorylated in all cell lines. Interestingly, cisplatin virtually abolished phosphorylation of p70S6K and 4EBP1 in CGC cells, while phosphorylation was maintained in cisplatin-treated AFPGC cells. The addition of rapamycin, an inhibitor of mTORC1, diminished the remaining activity of mTORC1 and significantly intensified the cytotoxic action of cisplatin in AFPGC cells. These results suggested that persistent activity of mTORC1 signals in cisplatin-treated AFPGC cells is involved in the mechanisms of cisplatin resistance in AFPGC. Finally, combined treatment of rapamycin and cisplatin significantly suppressed the subcutaneously implanted GCIY cells. In conclusion rapamycin may be a potential supplemental agent for the treatment of AFPGC when used in combination with cisplatin.

Influence of implant number on the biomechanical behaviour of mandibular implant-retained/supported overdentures: a three-dimensional finite element analysis.

PubMed

Liu, Jingyin; Pan, Shaoxia; Dong, Jing; Mo, Zhongjun; Fan, Yubo; Feng, Hailan

2013-03-01

The aim of this study was to evaluate strain distribution in peri-implant bone, stress in the abutments and denture stability of mandibular overdentures anchored by different numbers of implants under different loading conditions, through three-dimensional finite element analysis (3D FEA). Four 3D finite element models of mandibular overdentures were established, using between one and four Straumann implants with Locator attachments. Three types of load were applied to the overdenture in each model: 100N vertical and inclined loads on the left first molar and a 100N vertical load on the lower incisors. The biomechanical behaviours of peri-implant bone, implants, abutments and overdentures were recorded. Under vertical load on the lower incisors, the single-implant overdenture rotated over the implant from side to side, and no obvious increase of strain was found in peri-implant bone. Under the same loading conditions, the two-implant-retained overdenture showed more apparent rotation around the fulcrum line passing through the two implants, and the maximum equivalent stress in the abutments was higher than in the other models. In the three-implant-supported overdenture, no strain concentration was found in cortical bone around the middle implant under three loading conditions. Single-implant-retained mandibular overdentures do not show damaging strain concentration in the bone around the only implant and may be a cost-effective treatment option for edentulous patients. A third implant can be placed between the original two when patients rehabilitated by two-implant overdentures report constant and obvious denture rotation around the fulcrum line. Copyright © 2012 Elsevier Ltd. All rights reserved.

Role of HLA-G1 in trophoblast cell proliferation, adhesion and invasion

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jiang, Feng, E-mail: jiangfeng1161@163.com; Zhao, Hongxi; Wang, Li

Trophoblast cells are important in embryo implantation and fetomaternal tolerance. HLA-G is specifically expressed at the maternal–fetal interface and is a regulator in pregnancy. The aim of the present study was to detect the effect of HLA-G1 on trophoblast cell proliferation, adhesion, and invasion. Human trophoblast cell lines (JAR and HTR-8/SVneo cells) were infected with HLA-G1-expressing lentivirus. After infection, HLA-G1 expression of the cells was detected by western blotting. Cell proliferation was detected by the BrdU assay. The cell cycle and apoptosis of JAR and HTR-8/SVneo cells was measured by flow cytometry (FCM). The invasion of the cells under different conditionsmore » was detected by the transwell invasion chamber assay. HLA-G1 didn't show any significant influence on the proliferation, apoptosis, adhesion, and invasion of trophocytes in normal culture conditions. However, HLA-G1 inhibited JAR and HTR-8/SVneo cells invasion induced by hepatocyte growth factor (HGF) under normal oxygen conditions. In conditions of hypoxia, HLA-G1 couldn't inhibit the induction of cell invasion by HGF. HLA-G1 is not an independent factor for regulating the trophocytes. It may play an indirect role in embryo implantation and formation of the placenta. - Highlights: • HLA-G1 could not influence trophocytes under normal conditions. • HLA-G1 inhibited cell invasion induced by HGF under normal oxygen condition. • HLA-G1 could not influence cell invasion under hypoxia conditions.« less

A technique for transferring a patient's smile line to a cone beam computed tomography (CBCT) image.

PubMed

Bidra, Avinash S

2014-08-01

Fixed implant-supported prosthodontic treatment for patients requiring a gingival prosthesis often demands that bone and implant levels be apical to the patient's maximum smile line. This is to avoid the display of the prosthesis-tissue junction (the junction between the gingival prosthesis and natural soft tissues) and prevent esthetic failures. Recording a patient's lip position during maximum smile is invaluable for the treatment planning process. This article presents a simple technique for clinically recording and transferring the patient's maximum smile line to cone beam computed tomography (CBCT) images for analysis. The technique can help clinicians accurately determine the need for and amount of bone reduction required with respect to the maximum smile line and place implants in optimal positions. Copyright © 2014 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

Genotoxic Changes to Rodent Cells Exposed in Vitro to Tungsten, Nickel, Cobalt and Iron

PubMed Central

Bardack, Stephanie; Dalgard, Clifton L.; Kalinich, John F.; Kasper, Christine E.

2014-01-01

Tungsten-based materials have been proposed as replacements for depleted uranium in armor-penetrating munitions and for lead in small-arms ammunition. A recent report demonstrated that a military-grade composition of tungsten, nickel, and cobalt induced a highly-aggressive, metastatic rhabdomyosarcoma when implanted into the leg muscle of laboratory rats to simulate a shrapnel wound. The early genetic changes occurring in response to embedded metal fragments are not known. In this study, we utilized two cultured rodent myoblast cell lines, exposed to soluble tungsten alloys and the individual metals comprising the alloys, to study the genotoxic effects. By profiling cell transcriptomes using microarray, we found slight, yet distinct and unique, gene expression changes in rat myoblast cells after 24 h metal exposure, and several genes were identified that correlate with impending adverse consequences of ongoing exposure to weapons-grade tungsten alloy. These changes were not as apparent in the mouse myoblast cell line. This indicates a potential species difference in the cellular response to tungsten alloy, a hypothesis supported by current findings with in vivo model systems. Studies examining genotoxic-associated gene expression changes in cells from longer exposure times are warranted. PMID:24619124

Tissue-Specific Expression of Herpes Simplex Virus Thymidine Kinase Gene Delivered by Adeno-Associated Virus Inhibits the Growth of Human Hepatocellular Carcinoma in Athymic Mice

NASA Astrophysics Data System (ADS)

Su, Hua; Lu, Ronghua; Chang, Judy C.; Kan, Yuet Wai

1997-12-01

About 70% of hepatocellular carcinomas are known to express α -fetoprotein, which is normally expressed in fetal but not in adult livers. To induce herpes simplex virus-thymidine kinase expression in these cancer cells, we constructed an adeno-associated viral vector containing the HSV-TK gene under the control of the α -fetoprotein enhancer and albumin promoter. We previously demonstrated in vitro that although this vector can transduce a variety of human cells, only transduced AFP and albumin-expressing hepatocellular carcinoma cell lines were sensitive to killing by ganciclovir (GCV). In the present study, we explored the effect of this vector on hepatocellular carcinoma cells in vivo. Subcutaneous tumors generated in nude mice by implanting hepatocellular carcinoma cells previously transduced with this vector shrank dramatically after treatment with GCV. Bystander effect was also observed on the tumors generated by mixing transduced and untransduced cells. To test whether the tumor cells can be transduced by the virus in vivo, we injected the recombinant adeno-associated virus into tumors generated by untransduced hepatocarcinoma cell line. Tumor growth were retarded after treatment with GCV. These experiments demonstrate the feasibility of in vivo transduction of tumor cell with rAAV.

Ion implantation of solar cell junctions without mass analysis

NASA Technical Reports Server (NTRS)

Fitzgerald, D.; Tonn, D. G.

1981-01-01

This paper is a summary of an investigation to determine the feasibility of producing solar cells by means of ion implantation without the use of mass analysis. Ion implants were performed using molecular and atomic phosphorus produced by the vaporization of solid red phosphorus and ionized in an electron bombardment source. Solar cell junctions were ion implanted by mass analysis of individual molecular species and by direct unanalyzed implants from the ion source. The implant dose ranged from 10 to the 14th to 10 to the 16th atoms/sq cm and the energy per implanted atom ranged from 5 KeV to 40 KeV in this study.

Cellular delivery of human CNTF prevents motor and cognitive dysfunction in a rodent model of Huntington's disease.

PubMed

Emerich, D F; Cain, C K; Greco, C; Saydoff, J A; Hu, Z Y; Liu, H; Lindner, M D

1997-01-01

The delivery of ciliary neurotrophic factor (CNTF) to the central nervous system has recently been proposed as a potential means of halting or slowing the neural degeneration associated with Huntington's disease (HD). The following set of experiments examined, in detail, the ability of human CNTF (hCNTF) to prevent the onset of behavioral dysfunction in a rodent model of HD. A DHFR-based expression vector containing the hCNTF gene was transfected into a baby hamster kidney fibroblast cell line (BHK). Using a polymeric device, encapsulated BHK-control cells and those secreting hCNTF were transplanted bilaterally into rat lateral ventricles. Eight days later, the same animals received bilateral injections of quinolinic acid (QA, 225 nmol) into the previously implanted striata. A third group received sham surgery (incision only) and served as a normal control group. Bilateral infusions of QA produced a significant loss of body weight and mortality that was prevented by prior implantation with hCNTF-secreting cells. Moreover, QA produced a marked hyperactivity, an inability to use the forelimbs to retrieve food pellets in a staircase test, increased the latency of the rats to remove adhesive stimuli from their paws, and decreased the number of steps taken in a bracing test that assessed motor rigidity. Finally, the QA-infused animals were impaired in tests of cognitive function-the Morris water maze spatial learning task, and the delayed nonmatching-to-position operant test of working memory. Prior implantation with hCNTF-secreting cells prevented the onset of all the above deficits such that implanted animals were nondistinguishable from sham-lesioned controls. At the conclusion of behavioral testing, 19 days following QA, the animals were sacrificed for neurochemical determination of striatal choline acetyltransferase (ChAT) and glutamic acid decarboxylase (GAD) levels. This analysis revealed that QA decreased striatal ChAT levels by 35% and striatal GAD levels by 45%. In contrast, hCNTF-treated animals did not exhibit any decrease in ChAT levels and only a 10% decrease in GAD levels. These results support the concepts that implants of polymer-encapsulated hCNTF-releasing cells can be used to protect striatal neurons from excitotoxic damage, produce extensive behavioral protection as a result of that neuronal sparing, and that this strategy may ultimately prove relevant for the treatment of HD.

Diagnosis of anaplastic large cell lymphoma on late peri-implant breast seroma: Management of cytological sample by an integrated approach.

PubMed

Ronchi, A; Montella, M; Argenzio, V; Lucia, A; De Renzo, A; Alfano, R; Franco, R; Cozzolino, I

2018-04-06

Peri-implant breast seroma is a late clinical presentation of reconstructive surgery or augmentation mammoplasty with breast implants. Pre-operative cytological evaluation of the peri-implant breast seroma is a common clinical approach, showing mainly an inflammatory reaction or more rarely a breast implant-associated anaplastic large cell lymphoma. Herein, we reported the role of cytology in the evaluation of peri-implant breast seroma and its critical pre-operative implications. Eight cases of peri-implant breast seroma from files at Luigi Vanvitelli University were identified between January and December 2017. In all cases, seroma was aspirated; cytospins were performed and stained by Papanicolaou stain; finally, in all cases, a cell block was obtained for immunocytochemical evaluation and, in one case, for FISH to detect ALK1-gene translocation. The median age of patients was 48 years and the mean time between the implant placement and the occurrence of peri-implant breast seroma was 18 months. Microscopic examination showed breast implant-associated anaplastic large cell lymphoma in one case, aspecific inflammatory reaction in six cases and silicon-associated reaction in one case. Peri-implant breast seroma may be caused by several pathological conditions with different clinical behaviour. A proper cytological approach to peri-implant breast seroma allows a correct differential diagnosis between inflammatory conditions and breast implant-associated anaplastic large cell lymphoma and an appropriate management of the patient. © 2018 John Wiley & Sons Ltd.

Destiny of autologous bone marrow-derived stromal cells implanted in the vocal fold.

PubMed

Kanemaru, Shin-ichi; Nakamura, Tatsuo; Yamashita, Masaru; Magrufov, Akhmar; Kita, Tomoko; Tamaki, Hisanobu; Tamura, Yoshihiro; Iguchi, Fuku-ichiro; Kim, Tae Soo; Kishimoto, Masanao; Omori, Koichi; Ito, Juichi

2005-12-01

The aim of this study was to investigate the destiny of implanted autologous bone marrow-derived stromal cells (BSCs) containing mesenchymal stem cells. We previously reported the successful regeneration of an injured vocal fold through implantation of BSCs in a canine model. However, the fate of the implanted BSCs was not examined. In this study, implanted BSCs were traced in order to determine the type of tissues resulting at the injected site of the vocal fold. After harvest of bone marrow from the femurs of green fluorescent transgenic mice, adherent cells were cultured and selectively amplified. By means of a fluorescence-activated cell sorter, it was confirmed that some cells were strongly positive for mesenchymal stem cell markers, including CD29, CD44, CD49e, and Sca-1. These cells were then injected into the injured vocal fold of a nude rat. Immunohistologic examination of the resected vocal folds was performed 8 weeks after treatment. The implanted cells were alive in the host tissues and showed positive expression for keratin and desmin, markers for epithelial tissue and muscle, respectively. The implanted BSCs differentiated into more than one tissue type in vivo. Cell-based tissue engineering using BSCs may improve the quality of the healing process in vocal fold injuries.

The Effect of Finasteride and Dutasteride on the Growth of WPE1-NA22 Prostate Cancer Xenografts in Nude Mice

PubMed Central

Opoku-Acheampong, Alexander B.; Nelsen, Michelle K.; Unis, Dave; Lindshield, Brian L.

2012-01-01

Background 5α-reductase 1 (5αR1) and 5α-reductase 2 (5αR2) convert testosterone into the more potent androgen dihydrotestosterone. 5αR2 is the main isoenzyme in normal prostate tissue; however, most prostate tumors have increased 5αR1 and decreased 5αR2 expression. Previously, finasteride (5αR2 inhibitor) treatment begun 3 weeks post-tumor implantation had no effect on Dunning R3327-H rat prostate tumor growth. We believe the tumor compensated for finasteride treatment by increasing tumor 5αR1 expression or activity. We hypothesize that finasteride treatment would not significantly alter tumor growth even if begun before tumor implantation, whereas dutasteride (5αR1 and 5αR2 inhibitor) treatment would decrease tumor growth regardless of whether treatment was initiated before or after tumor implantation. Methodology/Principal Findings Sixty 8-week-old male nude mice were randomized to Control, Pre- and Post-Finasteride, and Pre- and Post-Dutasteride (83.3 mg drug/kg diet) diet groups. Pre- and post-groups began their treatment diets 1–2 weeks prior to or 3 weeks after subcutaneous injection of 1×105 WPE1-NA22 human prostate cancer cells, respectively. Tumors were allowed to grow for 22 weeks; tumor areas, body weights, and food intakes were measured weekly. At study's conclusion, prostate and seminal vesicle weights were significantly decreased in all treatment groups versus the control; dutasteride intake significantly decreased seminal vesicle weights compared to finasteride intake. No differences were measured in final tumor areas or tumor weights between groups, likely due to poor tumor growth. In follow-up studies, proliferation of WPE1-NA22 prostate cancer cells and parent line RWPE-1 prostate epithelial cells were unaltered by treatment with testosterone, dihydrotestosterone, or mibolerone, suggesting that these cell lines are not androgen-sensitive. Conclusion The lack of response of WPE1-NA22 prostate cancer cells to androgen treatment may explain the inadequate tumor growth observed. Additional studies are needed to determine whether finasteride and dutasteride are effective in decreasing prostate cancer development/growth. PMID:22242155

Suppression of thymosin β10 increases cell migration and metastasis of cholangiocarcinoma

PubMed Central

2013-01-01

Background Thymosin β10 (Tβ10) expression is associated with malignant phenotypes in many cancers. However, the role and mechanisms of Tβ10 in liver fluke-associated cholangiocarcinoma (CCA) are not fully understood. In this study, we investigated the expression of Tβ10 in CCA tumor tissues and cell lines as well as molecular mechanisms of Tβ10 in tumor metastasis of CCA cell lines. Methods Tβ10 expression was determined by real time RT-PCR or immunocytochemistry. Tβ10 silence or overexpression in CCA cells was achieved using gene delivery techniques. Cell migration was assessed using modified Boyden chamber and wound healing assay. The effect of silencing Tβ10 on CCA tumor metastasis was determined in nude mice. Phosphorylation of ERK1/2 and the expression of EGR1, Snail and matrix metalloproteinases (MMPs) were studied. Results Ten pairs of CCA tissues (primary and metastatic tumors) and 5 CCA cell lines were studied. With real time RT-PCR and immunostaining analysis, Tβ10 was highly expressed in primary tumors of CCA; while it was relatively low in the metastatic tumors. Five CCA cell lines showed differential expression levels of Tβ10. Silence of Tβ10 significantly increased cell migration, invasion and wound healing of CCA cells in vitro; reversely, overexpression of Tβ10 reduced cell migration compared with control cells (P<0.05). In addition, silence of Tβ10 in CCA cells increased liver metastasis in a nude mouse model of CCA implantation into the spleen. Furthermore, silence of Tβ10 activated ERK1/2 and increased the expression of Snail and MMPs in CCA cell lines. Ras-GTPase inhibitor, FPT inhibitor III, effectively blocked Tβ10 silence-associated ERK1/2 activation, Snail expression and cell migration. Conclusions Low expression of Tβ10 is associated with metastatic phenotype of CCA in vitro and in vivo, which may be mediated by the activation of Ras, ERK1/2 and upregulation of Snail and MMPs. This study suggests a new molecular pathway of CCA pathogenesis and a novel strategy to treat or prevent CCA metastasis. PMID:24053380

Development of patient-derived xenograft models from a spontaneously immortal low-grade meningioma cell line, KCI-MENG1.

PubMed

Michelhaugh, Sharon K; Guastella, Anthony R; Varadarajan, Kaushik; Klinger, Neil V; Parajuli, Prahlad; Ahmad, Aamir; Sethi, Seema; Aboukameel, Amro; Kiousis, Sam; Zitron, Ian M; Ebrahim, Salah A; Polin, Lisa A; Sarkar, Fazlul H; Bollig-Fischer, Aliccia; Mittal, Sandeep

2015-07-15

There is a paucity of effective therapies for recurrent/aggressive meningiomas. Establishment of improved in vitro and in vivo meningioma models will facilitate development and testing of novel therapeutic approaches. A primary meningioma cell line was generated from a patient with an olfactory groove meningioma. The cell line was extensively characterized by performing analysis of growth kinetics, immunocytochemistry, telomerase activity, karyotype, and comparative genomic hybridization. Xenograft models using immunocompromised SCID mice were also developed. Histopathology of the patient tumor was consistent with a WHO grade I typical meningioma composed of meningothelial cells, whorls, and occasional psammoma bodies. The original tumor and the early passage primary cells shared the standard immunohistochemical profile consistent with low-grade, good prognosis meningioma. Low passage KCI-MENG1 cells were composed of two cell types with spindle and round morphologies, showed linear growth curve, had very low telomerase activity, and were composed of two distinct unrelated clones on cytogenetic analysis. In contrast, high passage cells were homogeneously round, rapidly growing, had high telomerase activity, and were composed of a single clone with a near triploid karyotype containing 64-66 chromosomes with numerous aberrations. Following subcutaneous and orthotopic transplantation of low passage cells into SCID mice, firm tumors positive for vimentin and progesterone receptor (PR) formed, while subcutaneous implant of high passage cells yielded vimentin-positive, PR-negative tumors, concordant with a high-grade meningioma. Although derived from a benign meningioma specimen, the newly-established spontaneously immortal KCI-MENG1 meningioma cell line can be utilized to generate xenograft tumor models with either low- or high-grade features, dependent on the cell passage number (likely due to the relative abundance of the round, near-triploid cells). These human meningioma mouse xenograft models will provide biologically relevant platforms from which to investigate differences in low- vs. high-grade meningioma tumor biology and disease progression as well as to develop novel therapies to improve treatment options for poor prognosis or recurrent meningiomas.

Hybrid titanium/biodegradable polymer implants with an hierarchical pore structure as a means to control selective cell movement.

PubMed

Vrana, Nihal Engin; Dupret, Agnès; Coraux, Christelle; Vautier, Dominique; Debry, Christian; Lavalle, Philippe

2011-01-01

In order to improve implant success rate, it is important to enhance their responsiveness to the prevailing conditions following implantation. Uncontrolled movement of inflammatory cells and fibroblasts is one of these in vivo problems and the porosity properties of the implant have a strong effect on these. Here, we describe a hybrid system composed of a macroporous titanium structure filled with a microporous biodegradable polymer. This polymer matrix has a distinct porosity gradient to accommodate different cell types (fibroblasts and epithelial cells). The main clinical application of this system will be the prevention of restenosis due to excessive fibroblast migration and proliferation in the case of tracheal implants. A microbead-based titanium template was filled with a porous Poly (L-lactic acid) (PLLA) body by freeze-extraction method. A distinct porosity difference was obtained between the inner and outer surfaces of the implant as characterized by image analysis and Mercury porosimetry (9.8±2.2 µm vs. 36.7±11.4 µm, p≤0.05). On top, a thin PLLA film was added to optimize the growth of epithelial cells, which was confirmed by using human respiratory epithelial cells. To check the control of fibroblast movement, PKH26 labeled fibroblasts were seeded onto Titanium and Titanium/PLLA implants. The cell movement was quantified by confocal microscopy: in one week cells moved deeper in Ti samples compared to Ti/PLLA. In vitro experiments showed that this new implant is effective for guiding different kind of cells it will contact upon implantation. Overall, this system would enable spatial and temporal control over cell migration by a gradient ranging from macroporosity to nanoporosity within a tracheal implant. Moreover, mechanical properties will be dependent mainly on the titanium frame. This will make it possible to create a polymeric environment which is suitable for cells without the need to meet mechanical requirements with the polymeric structure.

Hybrid Titanium/Biodegradable Polymer Implants with an Hierarchical Pore Structure as a Means to Control Selective Cell Movement

PubMed Central

Vrana, Nihal Engin; Dupret, Agnès; Coraux, Christelle; Vautier, Dominique; Debry, Christian; Lavalle, Philippe

2011-01-01

In order to improve implant success rate, it is important to enhance their responsiveness to the prevailing conditions following implantation. Uncontrolled movement of inflammatory cells and fibroblasts is one of these in vivo problems and the porosity properties of the implant have a strong effect on these. Here, we describe a hybrid system composed of a macroporous titanium structure filled with a microporous biodegradable polymer. This polymer matrix has a distinct porosity gradient to accommodate different cell types (fibroblasts and epithelial cells). The main clinical application of this system will be the prevention of restenosis due to excessive fibroblast migration and proliferation in the case of tracheal implants. Methodology/Principal Findings A microbead-based titanium template was filled with a porous Poly (L-lactic acid) (PLLA) body by freeze-extraction method. A distinct porosity difference was obtained between the inner and outer surfaces of the implant as characterized by image analysis and Mercury porosimetry (9.8±2.2 µm vs. 36.7±11.4 µm, p≤0.05). On top, a thin PLLA film was added to optimize the growth of epithelial cells, which was confirmed by using human respiratory epithelial cells. To check the control of fibroblast movement, PKH26 labeled fibroblasts were seeded onto Titanium and Titanium/PLLA implants. The cell movement was quantified by confocal microscopy: in one week cells moved deeper in Ti samples compared to Ti/PLLA. Conclusions In vitro experiments showed that this new implant is effective for guiding different kind of cells it will contact upon implantation. Overall, this system would enable spatial and temporal control over cell migration by a gradient ranging from macroporosity to nanoporosity within a tracheal implant. Moreover, mechanical properties will be dependent mainly on the titanium frame. This will make it possible to create a polymeric environment which is suitable for cells without the need to meet mechanical requirements with the polymeric structure. PMID:21637824

Maternal corticosterone reduces egg fertility and hatchability and increases the numbers of early dead embryos in eggs laid by quail hens selected for exaggerated adrenocortical stress responsiveness.

PubMed

Schmidt, J B; Satterlee, D G; Treese, S M

2009-07-01

Quail hens selected for exaggerated (HS, high stress) rather than reduced (LS, low stress) plasma corticosterone (B) response to brief restraint deposit more B into their egg yolks than do LS hens. Female progeny of HS hens implanted with B also show reduced egg production when compared with female offspring of LS- and HS-control and LS-B-implanted hens. Herein, LS and HS hens were implanted (s.c.) with empty (controls, CON) or B-filled silastic tubes to assess the interactive influences of maternal B-treatment with quail stress line on egg fertility (FERT), total egg hatchability (TOTHATCH) and fertile egg hatchability, and the percentages of embryonic mortality (early dead, ED; late dead) and pipped eggs. Mean FERT was dramatically reduced in eggs of HS compared with LS hens and B-implanted compared with CON-treated hens (P < 0.0001, both cases). Line x implant treatment FERT outcomes partitioned (P < 0.05) as follows: LS-B = LS-CON > HS-CON > HS-B. In addition, TOTHATCH was also affected by line (LS > HS; P < 0.0001) and implant treatment (CON > B-implant; P < 0.0002) and line x implant treatment TOTHATCH means differed (P < 0.05) as follows: LS-CON = LS-B = HS-CON > HS-B. Fertile egg hatchability was reduced (P < 0.05) in HS-B-treated hen eggs when compared with LS-B and HS-CON hen eggs and more (P < 0.05) ED embryos were found in eggs laid by HS-B-implanted hens than in any other treatment group. Late dead and pipped egg percentages were unaffected by any treatment. The findings are important to avian geneticists because they further emphasize the benefits that selection for reduced adrenocortical responsiveness has on hen reproductive performance. The maternal B findings also warn poultry and hatchery managers that unless hen stress during egg formation is avoided, negative consequences in FERT, TOTHATCH, and ED can result, particularly in hens genetically predisposed toward exaggerated adrenal stress responsiveness.

Dispensing of very low volumes of ultra high viscosity alginate gels: a new tool for encapsulation of adherent cells and rapid prototyping of scaffolds and implants.

PubMed

Gepp, Michael M; Ehrhart, Friederike; Shirley, Stephen G; Howitz, Steffen; Zimmermann, Heiko

2009-01-01

We present a tool for dispensing very low volumes (20 nL or more) of ultra high viscosity (UHV) medical-grade alginate hydrogels. It uses a modified piezo-driven micrometering valve, integrated into a versatile system that allows fast prototyping of encapsulation procedures and scaffold production. Valves show excellent dispensing properties for UHV alginate in concentrations of 0.4% and 0.7% and also for aqueous liquids. An optimized process flow provides excellent handling of biological samples under sterile conditions. This technique allows the encapsulation of adherent cells and structuring of substrates for biotechnology and regenerative medicine. A variety of cell lines showed at least 70% viability after encapsulation (including cell lines that are relevant in regenerative medicine like Hep G2), and time-lapse analysis revealed cells proliferating and showing limited motility under alginate spots. Cells show metabolic activity, gene product expression, and physiological function. Encapsulated cells have contact with the substrate and can exchange metabolites while being isolated from macromolecules in the environment. Contactless dispensing allows structuring of substrates with alginate, isolation and transfer of cell-alginate complexes, and the dispensing of biological active hydrogels like extracellular matrix-derived gels.

Quantification of apoptotic DNA fragmentation in a transformed uterine epithelial cell line, HRE-H9, using capillary electrophoresis with laser-induced fluorescence detector (CE-LIF).

PubMed

Fiscus, R R; Leung, C P; Yuen, J P; Chan, H C

2001-01-01

Apoptotic cell death of uterine epithelial cells is thought to play an important role in the onset of menstruation and the successful implantation of an embryo during early pregnancy. Abnormal apoptosis in these cells can result in dysmenorrhoea and infertility. In addition, decreased rate of epithelial apoptosis likely contributes to endometriosis. A key step in the onset of apoptosis in these cells is cleavage of the genomic DNA between nucleosomes, resulting in polynucleosomal-sized fragments of DNA. The conventional technique for assessing apoptotic DNA fragmentation uses agarose (slab) gel electrophoresis (i.e. DNA laddering). However, recent technological advances in the use of capillary electrophoresis (CE), particularly the introduction of the laser-induced fluorescence detector (LIF), has made it possible to perform DNA laddering with improved automation and much greater sensitivity. In the present study, we have further developed the CE-LIF technique by using a DNA standard curve to quantify accurately the amount of DNA in the apoptotic DNA fragments and have applied this new quantitative technique to study apoptosis in a transformed uterine epithelial cell line, the HRE-H9 cells. Apoptosis was induced in the HRE-H9 cells by serum deprivation for 5, 7 and 24 h, resulting in increased DNA fragmentation of 2.2-, 3.1- and 6.2-fold, respectively, above the 0 h or plus-serum controls. This ultrasensitive CE-LIF technique provides a novel method for accurately measuring the actions of pro- or anti-apoptotic agents or conditions on uterine epithelial cell lines. Copyright 2001 Academic Press.

Investigation of gastric cancers in nude mice using X-ray in-line phase contrast imaging.

PubMed

Tao, Qiang; Luo, Shuqian

2014-07-24

This paper is to report the new imaging of gastric cancers without the use of imaging agents. Both gastric normal regions and gastric cancer regions can be distinguished by using the principal component analysis (PCA) based on the gray level co-occurrence matrix (GLCM). Human gastric cancer BGC823 cells were implanted into the stomachs of nude mice. Then, 3, 5, 7, 9 or 11 days after cancer cells implantation, the nude mice were sacrificed and their stomachs were removed. X-ray in-line phase contrast imaging (XILPCI), an X-ray phase contrast imaging method, has greater soft tissue contrast than traditional absorption radiography and generates higher-resolution images. The gastric specimens were imaged by an XILPCIs' charge coupled device (CCD) of 9 μm image resolution. The PCA of the projective images' region of interests (ROIs) based on GLCM were extracted to discriminate gastric normal regions and gastric cancer regions. Different stages of gastric cancers were classified by using support vector machines (SVMs). The X-ray in-line phase contrast images of nude mice gastric specimens clearly show the gastric architectures and the details of the early gastric cancers. The phase contrast computed tomography (CT) images of nude mice gastric cancer specimens are better than the traditional absorption CT images without the use of imaging agents. The results of the PCA of the texture parameters based on GLCM of normal regions is (F1+F2) >8.5, but those of cancer regions is (F1+F2) <8.5. The classification accuracy is 83.3% that classifying gastric specimens into different stages using SVMs. This is a very preliminary feasibility study. With further researches, XILPCI could become a noninvasive method for future the early detection of gastric cancers or medical researches.

In vitro adhesion of fibroblastic cells to titanium alloy discs treated with sodium hydroxide.

PubMed

Al Mustafa, Maisa; Agis, Hermann; Müller, Heinz-Dieter; Watzek, Georg; Gruber, Reinhard

2015-01-01

Adhesion of osteogenic cells on titanium surfaces is a prerequisite for osseointegration. Alkali treatment can increase the hydrophilicity of titanium implant surfaces, thereby supporting the adhesion of blood components. However, it is unclear if alkali treatment also supports the adhesion of cells with a fibroblastic morphology to titanium. Here, we have used a titanium alloy (Ti-6AL-4V) processed by alkali treatment to demonstrate the impact of hydrophilicity on the adhesion of primary human gingival fibroblast and bone cells. Also included were the osteosarcoma and fibroblastoma cell lines, MG63 and L929, respectively. Cell adhesion was determined by scanning electron microscopy. We also measured viability, proliferation, and protein synthesis of the adherent cells. Alkali treatment increased the adhesion of gingival fibroblasts, bone cells, and the two cell lines when seeded onto the titanium alloy surface for 1 h. At 3 h, no significant changes in cell adhesion were observed. Cells grown for 1 day on the titanium alloy surfaces processed by alkali treatment behave similarly to untreated controls with regard to viability, proliferation, and protein synthesis. Based on these preliminary In vitro findings, we conclude that alkali treatment can support the early adhesion of cells with fibroblastic characteristics to a titanium alloy surface. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Multimodality Imaging-based Evaluation of Single-Lumen Silicone Breast Implants for Rupture.

PubMed

Seiler, Stephen J; Sharma, Pooja B; Hayes, Jody C; Ganti, Ramapriya; Mootz, Ann R; Eads, Emily D; Teotia, Sumeet S; Evans, W Phil

2017-01-01

Breast implants are frequently encountered on breast imaging studies, and it is essential for any radiologist interpreting these studies to be able to correctly assess implant integrity. Ruptures of silicone gel-filled implants often occur without becoming clinically obvious and are incidentally detected at imaging. Early diagnosis of implant rupture is important because surgical removal of extracapsular silicone in the breast parenchyma and lymphatics is difficult. Conversely, misdiagnosis of rupture may prompt a patient to undergo unnecessary additional surgery to remove the implant. Mammography is the most common breast imaging examination performed and can readily depict extracapsular free silicone, although it is insensitive for detection of intracapsular implant rupture. Ultrasonography (US) can be used to assess the internal structure of the implant and may provide an economical method for initial implant assessment. Common US signs of intracapsular rupture include the "keyhole" or "noose" sign, subcapsular line sign, and "stepladder" sign; extracapsular silicone has a distinctive "snowstorm" or echogenic noise appearance. Magnetic resonance (MR) imaging is the most accurate and reliable means for assessment of implant rupture and is highly sensitive for detection of both intracapsular and extracapsular rupture. MR imaging findings of intracapsular rupture include the keyhole or noose sign, subcapsular line sign, and "linguine" sign, and silicone-selective MR imaging sequences are highly sensitive to small amounts of extracapsular silicone. © RSNA, 2017.

Fate of bone marrow stromal cells in a syngenic model of bone formation.

PubMed

Boukhechba, Florian; Balaguer, Thierry; Bouvet-Gerbettaz, Sébastien; Michiels, Jean-François; Bouler, Jean-Michel; Carle, Georges F; Scimeca, Jean-Claude; Rochet, Nathalie

2011-09-01

Bone marrow stromal cells (BMSCs) have been demonstrated to induce bone formation when associated to osteoconductive biomaterials and implanted in vivo. Nevertheless, their role in bone reconstruction is not fully understood and rare studies have been conducted to follow their destiny after implantation in syngenic models. The aim of the present work was to use sensitive and quantitative methods to track donor and recipient cells after implantation of BMSCs in a syngenic model of ectopic bone formation. Using polymerase chain reaction (PCR) amplification of the Sex determining Region Y (Sry) gene and in situ hybridization of the Y chromosome in parallel to histological analysis, we have quantified within the implants the survival of the donor cells and the colonization by the recipient cells. The putative migration of the BMSCs in peripheral organs was also analyzed. We show here that grafted cells do not survive more than 3 weeks after implantation and might migrate in peripheral lymphoid organs. These cells are responsible for the attraction of host cells within the implants, leading to the centripetal colonization of the biomaterial by new bone.

Localized Immunosuppressive Environment in the Foreign Body Response to Implanted Biomaterials

PubMed Central

Higgins, David M.; Basaraba, Randall J.; Hohnbaum, April C.; Lee, Eric J.; Grainger, David W.; Gonzalez-Juarrero, Mercedes

2009-01-01

The implantation of synthetic biomaterials initiates the foreign body response (FBR), which is characterized by macrophage infiltration, foreign body giant cell formation, and fibrotic encapsulation of the implant. The FBR is orchestrated by a complex network of immune modulators, including diverse cell types, soluble mediators, and unique cell surface interactions. The specific tissue locations, expression patterns, and spatial distribution of these immune modulators around the site of implantation are not clear. This study describes a model for studying the FBR in vivo and specifically evaluates the spatial relationship of immune modulators. We modified a biomaterials implantation in vivo model that allowed for cross-sectional in situ analysis of the FBR. Immunohistochemical techniques were used to determine the localization of soluble mediators, ie, interleukin (IL)-4, IL-13, IL-10, IL-6, transforming growth factor-β, tumor necrosis factor-α, interferon-γ, and MCP-1; specific cell types, ie, macrophages, neutrophils, fibroblasts, and lymphocytes; and cell surface markers, ie, F4/80, CD11b, CD11c, and Ly-6C, at early, middle, and late stages of the FBR in subcutaneous implant sites. The cytokines IL-4, IL-13, IL-10, and transforming growth factor-β were localized to implant-adherent cells that included macrophages and foreign body giant cells. A better understanding of the FBR in vivo will allow the development of novel strategies to enhance biomaterial implant design to achieve better performance and safety of biomedical devices at the site of implant. PMID:19528351

Localized immunosuppressive environment in the foreign body response to implanted biomaterials.

PubMed

Higgins, David M; Basaraba, Randall J; Hohnbaum, April C; Lee, Eric J; Grainger, David W; Gonzalez-Juarrero, Mercedes

2009-07-01

The implantation of synthetic biomaterials initiates the foreign body response (FBR), which is characterized by macrophage infiltration, foreign body giant cell formation, and fibrotic encapsulation of the implant. The FBR is orchestrated by a complex network of immune modulators, including diverse cell types, soluble mediators, and unique cell surface interactions. The specific tissue locations, expression patterns, and spatial distribution of these immune modulators around the site of implantation are not clear. This study describes a model for studying the FBR in vivo and specifically evaluates the spatial relationship of immune modulators. We modified a biomaterials implantation in vivo model that allowed for cross-sectional in situ analysis of the FBR. Immunohistochemical techniques were used to determine the localization of soluble mediators, ie, interleukin (IL)-4, IL-13, IL-10, IL-6, transforming growth factor-beta, tumor necrosis factor-alpha, interferon-gamma, and MCP-1; specific cell types, ie, macrophages, neutrophils, fibroblasts, and lymphocytes; and cell surface markers, ie, F4/80, CD11b, CD11c, and Ly-6C, at early, middle, and late stages of the FBR in subcutaneous implant sites. The cytokines IL-4, IL-13, IL-10, and transforming growth factor-beta were localized to implant-adherent cells that included macrophages and foreign body giant cells. A better understanding of the FBR in vivo will allow the development of novel strategies to enhance biomaterial implant design to achieve better performance and safety of biomedical devices at the site of implant.

The effect of Lipoxin A4 on the interaction between macrophage and osteoblast: possible role in the treatment of aseptic loosening.

PubMed

Li, Gang; Wu, Ping; Xu, Yao; Yu, Yan; Sun, Li; Zhu, Liang; Ye, Duyun

2009-06-02

Aseptic loosening (AL) is the main problem of total joints replacement (TJR) by the implantation of permanently prosthetic components. In vitro and in vivo studies have clearly demonstrated that wear debris and its byproducts could trigger inflammation in the peri-implant tissue. Lipoxins (LXs) are endogenous eicosanoids synthesized locally from arachidonate acid (AA) at sites of inflammation and mediate pro-resolving activity. A number of studies have demonstrated the effect of LXA4 to counteract inflammation in different cell and animal models, but till now, no relative report about the role of LXs in progress or prevention of AL. Murine RAW264.7 macrophage cell line and MC3T3-E1 osteoblasts (OB) cell line were purchased. Co-cultured model of these two cell lines was established. To explore the effect of exogenous Lipoxin A4 (LXA4) on polymethylmethacrylate (PMMA) induced inflammation, pro-inflammatory cytokines including TNF-alpha, IL-1beta, PGE2 and GM-CSF were measured by ELISA kits and bone resorption was quantified by measuring calcium release from 5-day-old mice calvaria in vitro. To determine further the endogenous effect of LXA4, cells were co-cultured and with or without 15-lipoxygease (15-LO) blocking by 15-LO siRNA. Both real-time PCR and western blotting were applied to confirm the inhibitory efficiency of 15-LO by siRNA. 0.1 mg/ml, 0.5 mg/ml and 1.0 mg/ml PMMA showed a time-dependent manner to trigger production of all the pro-inflammatory cytokines studied. Exogenous 0-100 nM LXA4 presented an inhibitory effect on both generation of above cytokines and PMMA stimulated calvarial bone resorption with a dose-dependent manner. LXA4 in supernatant from neither rest macrophages nor macrophages cultured alone exposing to PMMA was detectable. In co-cultured cells challenged by PMMA, LXA4 was increased significantly, while, this enhance could be partly inhibited by 15-LO siRNA. When LXA4 generation was blocked with 15-LO siRNA, the PMMA induced pro-inflammatory cytokines were elevated and bone resorption was accelerated. In the present study, we demonstrated that LXA4 had a favorable inhibitory effect on PMMA-induced inflammation in a macrophage and OB co-culture system.

The effect of Lipoxin A4 on the interaction between macrophage and osteoblast: possible role in the treatment of aseptic loosening

PubMed Central

Li, Gang; Wu, Ping; Xu, Yao; Yu, Yan; Sun, Li; Zhu, Liang; Ye, Duyun

2009-01-01

Background Aseptic loosening (AL) is the main problem of total joints replacement (TJR) by the implantation of permanently prosthetic components. In vitro and in vivo studies have clearly demonstrated that wear debris and its byproducts could trigger inflammation in the peri-implant tissue. Lipoxins (LXs) are endogenous eicosanoids synthesized locally from arachidonate acid (AA) at sites of inflammation and mediate pro-resolving activity. A number of studies have demonstrated the effect of LXA4 to counteract inflammation in different cell and animal models, but till now, no relative report about the role of LXs in progress or prevention of AL. Methods Murine RAW264.7 macrophage cell line and MC3T3-E1 osteoblasts (OB) cell line were purchased. Co-cultured model of these two cell lines was established. To explore the effect of exogenous Lipoxin A4 (LXA4) on polymethylmethacrylate (PMMA) induced inflammation, pro-inflammatory cytokines including TNF-α, IL-1β, PGE2 and GM-CSF were measured by ELISA kits and bone resorption was quantified by measuring calcium release from 5-day-old mice calvaria in vitro. To determine further the endogenous effect of LXA4, cells were co-cultured and with or without 15-lipoxygease (15-LO) blocking by 15-LO siRNA. Both real-time PCR and western blotting were applied to confirm the inhibitory efficiency of 15-LO by siRNA. Results 0.1 mg/ml, 0.5 mg/ml and 1.0 mg/ml PMMA showed a time-dependent manner to trigger production of all the pro-inflammatory cytokines studied. Exogenous 0–100 nM LXA4 presented an inhibitory effect on both generation of above cytokines and PMMA stimulated calvarial bone resorption with a dose-dependent manner. LXA4 in supernatant from neither rest macrophages nor macrophages cultured alone exposing to PMMA was detectable. In co-cultured cells challenged by PMMA, LXA4 was increased significantly, while, this enhance could be partly inhibited by 15-LO siRNA. When LXA4 generation was blocked with 15-LO siRNA, the PMMA induced pro-inflammatory cytokines were elevated and bone resorption was accelerated. Conclusion In the present study, we demonstrated that LXA4 had a favorable inhibitory effect on PMMA-induced inflammation in a macrophage and OB co-culture system. PMID:19490628

Formononetin induces apoptosis of human osteosarcoma cell line U2OS by regulating the expression of Bcl-2, Bax and MiR-375 in vitro and in vivo.

PubMed

Hu, Wei; Xiao, ZengMing

2015-01-01

Phytoestrogens are known to prevent tumor progression by inhibiting proliferation and inducing apoptosis in cancer cells. Formononetin is one of the main components of red clover plants, and is considered as a typical phytoestrogen. This study investigates formononetin induction of apoptosis of human osteosarcoma cell line U2OS by regulating Bcl-2 and Bax expression in vitro and in vivo. U2OS cells were treated with different concentrations of formononetin and the proliferation of the cells was measured using an MTT assay. Cell apoptosis was examined by flow cytometry. The levels of miR-375, Bax and Bcl-2 protein expression in treated cells were determined by Western blot and RT-PCR. The antitumor activity of formononetin was also evaluated in vivo in nude mice bearing orthotopic tumor implants. High concentrations of formononetin significantly suppress the proliferation of U2OS cells and induce cell apoptosis. Moreover, compared to control group the expression of Bcl-2 and miR-375 decreases with formononetin in the U2OS cells, while Bax increases. Formononetin has inhibitory effects on the proliferation of U2SO cells, both in vitro and in vivo. This antitumor effect is directly correlated with formononetin concentration. © 2015 The Author(s) Published by S. Karger AG, Basel.

The effect of incorporation of SDF-1alpha into PLGA scaffolds on stem cell recruitment and the inflammatory response.

PubMed

Thevenot, Paul T; Nair, Ashwin M; Shen, Jinhui; Lotfi, Parisa; Ko, Cheng-Yu; Tang, Liping

2010-05-01

Despite significant advances in the understanding of tissue responses to biomaterials, most implants are still plagued by inflammatory responses which can lead to fibrotic encapsulation. This is of dire consequence in tissue engineering, where seeded cells and bioactive components are separated from the native tissue, limiting the regenerative potential of the design. Additionally, these interactions prevent desired tissue integration and angiogenesis, preventing functionality of the design. Recent evidence supports that mesenchymal stem cells (MSC) and hematopoietic stem cells (HSC) can have beneficial effects which alter the inflammatory responses and improve healing. The purpose of this study was to examine whether stem cells could be targeted to the site of biomaterial implantation and whether increasing local stem cell responses could improve the tissue response to PLGA scaffold implants. Through incorporation of SDF-1alpha through factor adsorption and mini-osmotic pump delivery, the host-derived stem cell response can be improved resulting in 3X increase in stem cell populations at the interface for up to 2 weeks. These interactions were found to significantly alter the acute mast cell responses, reducing the number of mast cells and degranulated mast cells near the scaffold implants. This led to subsequent downstream reduction in the inflammatory cell responses, and through altered mast cell activation and stem cell participation, increased angiogenesis and decreased fibrotic responses to the scaffold implants. These results support that enhanced recruitment of autologous stem cells can improve the tissue responses to biomaterial implants through modifying/bypassing inflammatory cell responses and jumpstarting stem cell participation in healing at the implant interface. Copyright 2010 Elsevier Ltd. All rights reserved.

The Effect of Incorporation of SDF-1α into PLGA Scaffolds on Stem Cell Recruitment and the Inflammatory Response

PubMed Central

Thevenot, Paul; Nair, Ashwin; Shen, Jinhui; Lotfi, Parisa; Ko, Cheng Yu; Tang, Liping

2010-01-01

Despite significant advances in the understanding of tissue responses to biomaterials, most implants are still plagued by inflammatory responses which can lead to fibrotic encapsulation. This is of dire consequence in tissue engineering, where seeded cells and bioactive components are separated from the native tissue, limiting the regenerative potential of the design. Additionally, these interactions prevent desired tissue integration and angiogenesis, preventing functionality of the design. Recent evidence supports that mesenchymal stem cells (MSC) and hematopoietic stem cells (HSC) can have beneficial effects which alter the inflammatory responses and improve healing. The purpose of this study was to examine whether stem cells could be targeted to the site of biomaterial implantation and whether increasing local stem cell responses could improve the tissue response to PLGA scaffold implants. Through incorporation of SDF-1α through factor adsorption and mini-osmotic pump delivery, the host-derived stem cell response can be improved resulting in 3X increase in stem cell populations at the interface for up to 2 weeks. These interactions were found to significantly alter the acute mast cell responses, reducing the number of mast cells and degranulated mast cells near the scaffold implants. This led to subsequent downstream reduction in the inflammatory cell responses, and through altered mast cell activation and stem cell participation, increased angiogenesis and decreased fibrotic responses to the scaffold implants. These results support that enhanced recruitment of autologous stem cells can improve the tissue responses to biomaterial implants through modifying/bypassing inflammatory cell responses and jumpstarting stem cell participation in healing at the implant interface. PMID:20185171

Nuclear donor cell lines considerably influence cloning efficiency and the incidence of large offspring syndrome in bovine somatic cell nuclear transfer.

PubMed

Liu, J; Wang, Y; Su, J; Luo, Y; Quan, F; Zhang, Y

2013-08-01

Total five ear skin fibroblast lines (named F1, F2, F3, F4 and F5) from different newborn Holstein cows have been used as nuclear donor cells for producing cloned cows by somatic cell nuclear transfer (SCNT). The effects of these cell lines on both in vitro and in vivo developmental rates of cloned embryos, post-natal survivability and incidence of large offspring syndrome (LOS) were examined in this study. We found that the different cell lines possessed the same capacity to support pre-implantation development of cloned embryos, the cleavage and blastocyst formation rates ranged from 80.2 ± 0.9 to 84.5 ± 2.5% and 28.5 ± 0.9 to 33.3 ± 1.4%, respectively. However, their capacities to support the in vivo development of SCNT embryos showed significant differences (p < 0.05). The pregnancy rates at 90 and 240 day were significantly lower in groups F2 (4.9% and 3.3%) and F3 (5.4% and 5.4%) compared to groups F1 (23.3% and 16.3%), F4 (25.7% and 18.6%) and F5 (25.9% and 19.8%) (p < 0.05). The cloning efficiency was significantly higher in group F5 than those in group F1, F2, F3 and F4 (9.3% vs 4.1%, 1.2%, 2.0% and 5.0%, respectively, p < 0.05). Moreover, large offspring syndrome (LOS) incidence in group F5 was significantly lower than those in other groups (p < 0.05). All cloned offspring from cell line F1, F2, F3 and F4 showed LOS and gestation length delay, while all cloned offspring from F5 showed normal birthweight and gestation length. We concluded that the nuclear donor cell lines have significant impact on the in vivo development of cloned embryos and the incidence of LOS in cloned calves. © 2013 Blackwell Verlag GmbH.

Encapsulated VEGF-secreting cells enhance proliferation of neuronal progenitors in the hippocampus of AβPP/Ps1 mice.

PubMed

Antequera, Desiree; Portero, Aitziber; Bolos, Marta; Orive, Gorka; Hernández, Rosa M Rm A; Pedraz, José Luis; Carro, Eva

2012-01-01

Vascular endothelial growth factor (VEGF) promotes neurogenesis in the adult hippocampus, but the way in which this process occurs in the Alzheimer's disease (AD) brain is still unknown. We examined the proliferation of neuronal precursors with an ex vivo approach, using encapsulated VEGF secreting cells, in AβPP/PS1 mice, a mouse model of AD. Overexpression of VEGF and VEGF receptor flk-1 was observed in the cerebral cortex from VEGF microcapsules-treated AβPP/PS1 mice at 1, 3 and 6 months after VEGF-microcapsule implantation. Stereological counting of 5-bromodeoxyuridine positive cells revealed that encapsulated VEGF secreting cells significantly enhanced cellular proliferation in the hippocampal dentate gyrus (DG). The number of neuronal precursors in VEGF microcapsules-treated AβPP/PS1 mice was also greater, and this effect remains after 6 months. We also confirmed that encapsulated VEGF secreting cells also stimulated angiogenesis in the cerebral cortex and hippocampal dentate gyrus. In addition, we found that VEGF-microcapsule treatment was associated with a depressed expression and activity of acetylcholinesterase in the hippocampus of AβPP/PS1 mice, a similar pattern as first-line medications for the treatment of AD. We conclude that stereologically-implanted VEGF-microcapsules exert an acute and long-standing neurotrophic effects, and could be utilized to improve potential therapies to control the progression of AD.

Behavior of bone cells in contact with magnesium implant material.

PubMed

Burmester, Anna; Willumeit-Römer, Regine; Feyerabend, Frank

2017-01-01

Magnesium-based implants exhibit several advantages, such as biodegradability and possible osteoinductive properties. Whether the degradation may induce cell type-specific changes in metabolism still remains unclear. To examine the osteoinductivity mechanisms, the reaction of bone-derived cells (MG63, U2OS, SaoS2, and primary human osteoblasts (OB)) to magnesium (Mg) was determined. Mg-based extracts were used to mimic more realistic Mg degradation conditions. Moreover, the influence of cells having direct contact with the degrading Mg metal was investigated. In exposure to extracts and in direct contact, the cells decreased pH and osmolality due to metabolic activity. Proliferating cells showed no significant reaction to extracts, whereas differentiating cells were negatively influenced. In contrast to extract exposure, where cell size increased, in direct contact to magnesium, cell size was stable or even decreased. The amount of focal adhesions decreased over time on all materials. Genes involved in bone formation were significantly upregulated, especially for primary human osteoblasts. Some osteoinductive indicators were observed for OB: (i) an increased cell count after extract addition indicated a higher proliferation potential; (ii) increased cell sizes after extract supplementation in combination with augmented adhesion behavior of these cells suggest an early switch to differentiation; and (iii) bone-inducing gene expression patterns were determined for all analyzed conditions. The results from the cell lines were inhomogeneous and showed no specific stimulus of Mg. The comparison of the different cell types showed that primary cells of the investigated tissue should be used as an in vitro model if Mg is analyzed. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 165-179, 2017. © 2015 Wiley Periodicals, Inc.

Cell-based delivery of glucagon-like peptide-1 using encapsulated mesenchymal stem cells.

PubMed

Wallrapp, Christine; Thoenes, Eric; Thürmer, Frank; Jork, Anette; Kassem, Moustapha; Geigle, Peter

2013-01-01

Glucagon-like peptide-1 (GLP-1) CellBeads are cell-based implants for the sustained local delivery of bioactive factors. They consist of GLP-1 secreting mesenchymal stem cells encapsulated in a spherically shaped immuno-isolating alginate matrix. A highly standardized and reproducible encapsulation method is described for the manufacturing of homogeneous CellBeads. Viability and sustained secretion was shown for the recombinant GLP-1 and the cell endogenous bioactive factors like vascular endothelial growth factor, neurotrophin 3 (NT-3) and glial cell line-derived neurotrophic factor. Manufacturing and quality control is performed in compliance with good manufacturing practice and fulfils all regulatory requirements for human clinical use. GLP-1 CellBeads combine the neuro- and cardioprotective properties of both GLP-1 and mesenchymal stem cells. First promising results were obtained from preclinical studies and an ongoing safety trial in humans but further studies have to prove the overall potential of CellBead technology in cell-based regenerative medicine.

Pretreatment with platelet derived growth factor-BB modulates the ability of costochondral resting zone chondrocytes incorporated into PLA/PGA scaffolds to form new cartilage in vivo.

PubMed

Lohmann, C H; Schwartz, Z; Niederauer, G G; Carnes, D L; Dean, D D; Boyan, B D

2000-01-01

Optimal repair of chondral defects is likely to require both a suitable population of chondrogenic cells and a biodegradable matrix to provide a space-filling structural support during the early stages of cartilage formation. This study examined the ability of chondrocytes to support cartilage formation when incorporated into biodegradable scaffolds constructed from copolymers (PLG) of polylactic acid (PLA) and polyglycolic acid (PGA) and implanted in the calf muscle of nude mice. Scaffolds were fabricated to be more hydrophilic (PLG-H) or were reinforced with 10% PGA fibers (PLG-FR), increasing the stiffness of the implant by 20-fold. Confluent primary cultures of rat costochondral resting zone chondrocytes (RC) were loaded into PLG-H foams and implanted intramuscularly. To determine if growth factor pretreatment could modulate the ability of the cells to form new cartilage, RC cells were pretreated with recombinant human platelet derived growth factor-BB IPDGF-BB) for 4 or 24 h prior to implantation. To assess whether scaffold material properties could affect the ability of chondrogenic cells to form cartilage, RC cells were also loaded into PLG-FR scaffolds. To determine if the scaffolds or treatment with PDGF-BB affected the rate of chondrogenesis, tissue at the implant site was harvested at four and eight weeks post-operatively, fixed, decalcified and embedded in paraffin. Sections were obtained along the transverse plane of the lower leg, stained with haematoxylin and eosin, and then assessed by morphometric analysis for area of cartilage, area of residual implant, and area of fibrous connective tissue formation (fibrosis). Whether or not the cartilage contained hypertrophic cells was also assessed. The amount of residual implant did not change with time in any of the implanted tissues. The area occupied by PLG-FR implants was greater than that occupied by PLG-H implants at both time points. All implants were surrounded by fibrous connective tissue, whether they were seeded with RC cells or not. The amount of fibrosis was reduced at eight weeks for both implant types. When RC cells were present, the amount of fibrosis was less than seen in cell-free scaffolds. Pretreatment with PDGF-BB caused a slightly greater degree of fibrosis at four weeks than was seen if untreated cells were used in the implants. However, at eight weeks, if the cells had been exposed to PDGF-BB for 24 h, fibrosis was comparable to that seen associated with cell-free scaffolds. The cells supported an equivalent area of cartilage formation in both scaffolds. PDGF-BB caused a time-dependent decrease in cartilage formation at four weeks, but at eight weeks, there was a marked increase in cartilage formation in PDGF-BB-treated cells that was greatest in cells exposed for 4 h compared to those exposed for 24 h. Moreover, PDGF-BB decreased the formation of hypertrophic cells. The results indicate that in this model, RC cells produce cartilage; pretreatment of the RC cells with PDGF-BB promotes retention of a hyaline-like chondrogenic phenotype; and the material properties of the implant do not negatively impact on the ability of the cells to support chondrogenesis.

Surface Oxide Net Charge of a Titanium Alloy ; Modulation of Fibronectin-Activated Attachment and Spreading of Osteogenic Cells

PubMed Central

Rapuano, Bruce E.; MacDonald, Daniel E.

2010-01-01

In the current study, we have altered the surface oxide properties of a Ti6Al4V alloy using heat treatment or radiofrequency glow discharge (RFGD) in order to evaluate the relationship between the physico-chemical and biological properties of the alloy's surface oxide. The effects of surface pretreatments on the attachment of cells from two osteogenic cell lines (MG63 and MC3T3) and a mesenchymal stem cell line (C3H10T1/2) to fibronectin adsorbed to the alloy were measured. Both heat and RFGD pretreatments produced a several-fold increase in the number of cells that attached to fibronectin adsorbed to the alloy (0.001 and 10 nM FN) for each cell line tested. An antibody (HFN7.1) directed against the central integrin binding domain of fibronectin produced a 65-70% inhibition of cell attachment to fibronectin-coated disks, incdicating that cell attachment to the metal discs was dependent on fibronectin binding to cell integrin receptors. Both treatments also accelerated the cell spreading response manifested by extensive flattening and an increase in mean cellular area. The treatment-induced increases in the cell attachment activity of adsorbed fibronectin were correlated with previously demonstrated increases in Ti6Al4V oxide negative net surface charge at physiological pH produced by both heat and RFGD pretreatments. Since neither treatment increased the adsorption mass of fibronectin, these findings suggest that negatively charged surface oxide functional groups in Ti6Al4V can modulate fibronectin's integrin receptor activity by altering the adsorbed protein's conformation. Our results further suggest that negatively charged functional groups in the surface oxide can play a prominent role in the osseointegration of metallic implant materials. PMID:20884181

Microbial colonization at the implant-abutment interface and its possible influence on periimplantitis: A systematic review and meta-analysis.

PubMed

Tallarico, Marco; Canullo, Luigi; Caneva, Martina; Özcan, Mutlu

2017-07-01

The aim of this systematic review and meta-analysis was to evaluate the microbial colonization at the implant-abutment interfaces (IAI) on bone-level implants and to identify possible association with peri-implant conditions. The focus question aimed to answer whether two-piece osseointegrated implants, in function for at least 1 year, in human, relate to higher bacterial count and the onset of periimplantitis, compared to healthy peri-implant conditions. Search strategy encompassed the on-line (MedLine, Google scholar, Cochrane library) literature from 1990 up to March 2015 published in English using combinations of MeSH (Medical Subject Headings) and search terms. Quality assessment of selected full-text articles was performed according to the ARRIVE and CONSORT statement guidelines. For data analysis, the total bacterial count of Porphyromonas gingivalis, Tannerella forsythia, Treponema denticola, Prevotella intermedia, and Fusobacterium nucleatum was calculated and compared to IAI with or without peri-implant pathology. A total of 14 articles, reporting data from 1126 implants, fulfilled the inclusion criteria and subjected to quality assessment. The selected studies revealed contamination of the IAI, in patients who received two-piece implant systems. Meta-analysis indicated significant difference in total bacterial count between implants affected by periimplantitis versus healthy peri-implant tissues (0.387±0.055; 95% CI 0.279-0.496). Less bacterial counts were identified in the healthy IAI for all the investigated gram-negative bacteria except for T. forsythia. Significantly higher bacterial counts were found for periodontal pathogenic bacteria within the IAI of implants in patients with periimplantitis compared to those implants surrounded by healthy peri-implant tissues. Copyright © 2017 Japan Prosthodontic Society. Published by Elsevier Ltd. All rights reserved.

Perfluorocarbon-Loaded Lipid Nanocapsules to Assess the Dependence of U87-Human Glioblastoma Tumor pO2 on In Vitro Expansion Conditions

PubMed Central

Lemaire, Laurent; Nel, Janske; Franconi, Florence; Bastiat, Guillaume; Saulnier, Patrick

2016-01-01

Growing tumor cell lines, such as U87-MG glioma cells, under mild hypoxia (3% O2) leads to a ca. 40% reduction in growth rate once implanted in the brain of nude mice, as compared to normoxia (21% O2) grown cells, wherein the former over-express HIF-1 and VEGF-A. Despite developing differently, the tumors have similar: blood perfusion, oxygen consumption, and vascular surface area parameters, whereas the number of blood vessels is nearly doubled in the tumor arising from normoxia cultured cells. Interestingly, tumor oxygen tension, measured using 19F-oximetry, showed that the normoxia grown cells led to tumors characterized by mild hypoxic environment (approximately 4%) conditions, whilst the hypoxia grown cells led to tumors characterized by physioxic environment (approximately 6%) conditions. This reversal in oxygen concentration may be responsible for the apparent paradoxical growth profiles. PMID:27788227

The Safety and Predictability of Implanting Autologous Lenticule Obtained by SMILE for Hyperopia.

PubMed

Sun, Ling; Yao, Peijun; Li, Meiyan; Shen, Yang; Zhao, Jing; Zhou, Xingtao

2015-06-01

To evaluate the safety, effectiveness, stability, and predictability of implanting autologous lenticules obtained from small incision lenticule extraction for the treatment of hyperopia. Five patients (10 eyes) with one myopic eye and one hyperopic eye were enrolled. The myopic eye was treated with small incision lenticule extraction; a lenticule was extracted and subsequently implanted in the hyperopic eye. Follow-up was at 1 day, 1, 3, 6, and 9 months, and 1 year postoperatively. Patients received a complete ophthalmologic examination at each visit, including uncorrected distance visual acuity, corrected distance visual acuity, anterior segment optical coherence tomography, and corneal topography. There were no complications in any eye during follow-up. Compared with preoperative levels, at the last follow-up visit the eyes with lenticule implantation showed mean spherical equivalent reduced by 5.53 diopters (residual spherical equivalent was +1.13 to -2.63 diopters), mean uncorrected distance visual acuity increased approximately two lines (approximately 20/63 to 20/40 Snellen), and corrected distance visual acuity in 4 (80%) eyes gained one line, 2 (40%) eyes gained two lines, and 1 (20%) eye gained more than two lines. There was no significant difference (P > .05) in spherical equivalent compared with 1 day postoperatively and the last follow-up visit. Corneal topography showed that the lenticule was uniform and located well; anterior segment optical coherence tomography images showed that the lenticule was transparent and the demarcation line was visible. Implanting an autologous lenticule obtained by small incision lenticule extraction for hyperopia might be safe, effective, and stable, but its predictability should be improved in the future. Copyright 2015, SLACK Incorporated.

Suspension Matrices for Improved Schwann-Cell Survival after Implantation into the Injured Rat Spinal Cord

PubMed Central

Patel, Vivek; Joseph, Gravil; Patel, Amit; Patel, Samik; Bustin, Devin; Mawson, David; Tuesta, Luis M.; Puentes, Rocio; Ghosh, Mousumi

2010-01-01

Abstract Trauma to the spinal cord produces endogenously irreversible tissue and functional loss, requiring the application of therapeutic approaches to achieve meaningful restoration. Cellular strategies, in particular Schwann-cell implantation, have shown promise in overcoming many of the obstacles facing successful repair of the injured spinal cord. Here, we show that the implantation of Schwann cells as cell suspensions with in-situ gelling laminin:collagen matrices after spinal-cord contusion significantly enhances long-term cell survival but not proliferation, as well as improves graft vascularization and the degree of axonal in-growth over the standard implantation vehicle, minimal media. The use of a matrix to suspend cells prior to implantation should be an important consideration for achieving improved survival and effectiveness of cellular therapies for future clinical application. PMID:20144012

Histological features of pseudotumor-like tissues from metal-on-metal hips.

PubMed

Campbell, Pat; Ebramzadeh, Edward; Nelson, Scott; Takamura, Karren; De Smet, Koen; Amstutz, Harlan C

2010-09-01

Pseudotumor-like periprosthetic tissue reactions around metal-on-metal (M-M) hip replacements can cause pain and lead to revision surgery. The cause of these reactions is not well understood but could be due to excessive wear, or metal hypersensitivity or an as-yet unknown cause. The tissue features may help distinguish reactions to high wear from those with suspected metal hypersensitivity. We therefore examined the synovial lining integrity, inflammatory cell infiltrates, tissue organization, necrosis and metal wear particles of pseudotumor-like tissues from M-M hips revised for suspected high wear related and suspected metal hypersensitivity causes. Tissue samples from 32 revised hip replacements with pseudotumor-like reactions were studied. A 10-point histological score was used to rank the degree of aseptic lymphocytic vasculitis-associated lesions (ALVAL) by examination of synovial lining integrity, inflammatory cell infiltrates, and tissue organization. Lymphocytes, macrophages, plasma cells, giant cells, necrosis and metal wear particles were semiquantitatively rated. Implant wear was measured with a coordinate measuring machine. The cases were divided into those suspected of having high wear and those suspected of having metal hypersensitivity based on clinical, radiographic and retrieval findings. The Mann-Whitney test was used to compare the histological features in these two groups. The tissues from patients revised for suspected high wear had a lower ALVAL score, fewer lymphocytes, but more macrophages and metal particles than those tissues from hips revised for pain and suspected metal hypersensitivity. The highest ALVAL scores occurred in patients who were revised for pain and suspected metal hypersensitivity. Component wear was lower in that group. Pseudotumor-like reactions can be caused by high wear, but may also occur around implants with low wear, likely because of a metal hypersensitivity reaction. Histologic features including synovial integrity, inflammatory cell infiltrates, tissue organization, and metal particles may help differentiate these causes. Painful hips with periprosthetic masses may be caused by high wear, but if this can be ruled out, metal hypersensitivity should be considered.

Quantitative grading of a human blastocyst: optimal inner cell mass size and shape.

PubMed

Richter, K S; Harris, D C; Daneshmand, S T; Shapiro, B S

2001-12-01

To investigate the predictive value of quantitative measurements of blastocyst morphology on subsequent implantation rates after transfer. Prospective observational study. Private assisted reproductive technology center. One hundred seventy-four IVF patients receiving transfers of expanded blastocyst-stage embryos on day 5 (n = 112) or day 6 (n = 62) after oocyte retrieval. None. Blastocyst diameter, number of trophectoderm cells, inner cell mass (ICM) size, ICM shape, and implantation and pregnancy rates. Blastocyst diameter and trophectoderm cell numbers were unrelated to implantation rates. Day 5 expanded blastocysts with ICMs of >4,500 microm(2) implanted at a higher rate than did those with smaller ICMs (55% vs. 31%). Day 5 expanded blastocysts with slightly oval ICMs implanted at a higher rate (58%) compared with those with either rounder ICMs (7%) or more elongated ICMs (33%). Implantation rates were highest (71%) for embryos with both optimal ICM size and shape. Pregnancy rates were higher for day 5 transfers of optimally shaped ICMs compared with day 5 transfers of optimally sized ICMs. Quantitative measurements of the inner cell mass are highly indicative of blastocyst implantation potential. Blastocysts with relatively large and/or slightly oval ICMs are more likely to implant than other blastocysts.

Modification of anti-bacterial surface properties of textile polymers by vacuum arc ion source implantation

NASA Astrophysics Data System (ADS)

Nikolaev, A. G.; Yushkov, G. Yu.; Oks, E. M.; Oztarhan, A.; Akpek, A.; Hames-Kocabas, E.; Urkac, E. S.; Brown, I. G.

2014-08-01

Ion implantation provides an important technology for the modification of material surface properties. The vacuum arc ion source is a unique instrument for the generation of intense beams of metal ions as well as gaseous ions, including mixed metal-gas beams with controllable metal:gas ion ratio. Here we describe our exploratory work on the application of vacuum arc ion source-generated ion beams for ion implantation into polymer textile materials for modification of their biological cell compatibility surface properties. We have investigated two specific aspects of cell compatibility: (i) enhancement of the antibacterial characteristics (we chose to use Staphylococcus aureus bacteria) of ion implanted polymer textile fabric, and (ii) the "inverse" concern of enhancement of neural cell growth rate (we chose Rat B-35 neuroblastoma cells) on ion implanted polymer textile. The results of both investigations were positive, with implantation-generated antibacterial efficiency factor up to about 90%, fully comparable to alternative conventional (non-implantation) approaches and with some potentially important advantages over the conventional approach; and with enhancement of neural cell growth rate of up to a factor of 3.5 when grown on suitably implanted polymer textile material.

Manifestation of Metastatic Potential in Human Gastric Cancer Implanted into the Stomach Wall of Nude Mice

PubMed Central

Yamashita, Takumi

1988-01-01

The biological properties of human gastric cancer cell line G/F implanted into either the subcutis or the stomach wall of nude mice were compared. The G/F tumor in the stomach wall showed a slower growth rate than that in the subcutis. The level of carcinoembryonic antigen in serum was greater when the tumor was in the stomach wall than when it was in the subcutis. The tumor in the stomach wall invaded the surrounding tissues and metastasized to the regional lymph nodes and distant organs such as the lung and the liver in 27 of the 43 mice (68%). In contrast, the tumor in the subcutis was highly encapsulated and metastasis to other organs was not observed. These findings indicate that the stomach wall might provide a suitable microenvironment for G/F gastric cancer to exert its intrinsic properties. Therefore, implantation of human gastric cancer into the stomach wall of nude mice may provide a useful model to study the intrinsic characteristics of human cancer as well as the effectiveness of experimental chemotherapy. PMID:3141329

Toward angiogenesis of implanted bio-artificial liver using scaffolds with type I collagen and adipose tissue-derived stem cells.

PubMed

Lee, Jae Geun; Bak, Seon Young; Nahm, Ji Hae; Lee, Sang Woo; Min, Seon Ok; Kim, Kyung Sik

2015-05-01

Stem cell therapies for liver disease are being studied by many researchers worldwide, but scientific evidence to demonstrate the endocrinologic effects of implanted cells is insufficient, and it is unknown whether implanted cells can function as liver cells. Achieving angiogenesis, arguably the most important characteristic of the liver, is known to be quite difficult, and no practical attempts have been made to achieve this outcome. We carried out this study to observe the possibility of angiogenesis of implanted bio-artificial liver using scaffolds. This study used adipose tissue-derived stem cells that were collected from adult patients with liver diseases with conditions similar to the liver parenchyma. Specifically, microfilaments were used to create an artificial membrane and maintain the structure of an artificial organ. After scratching the stomach surface of severe combined immunocompromised (SCID) mice (n=4), artificial scaffolds with adipose tissue-derived stem cells and type I collagen were implanted. Expression levels of angiogenesis markers including vascular endothelial growth factor (VEGF), CD34, and CD105 were immunohistochemically assessed after 30 days. Grossly, the artificial scaffolds showed adhesion to the stomach and surrounding organs; however, there was no evidence of angiogenesis within the scaffolds; and VEGF, CD34, and CD105 expressions were not detected after 30 days. Although implantation of cells into artificial scaffolds did not facilitate angiogenesis, the artificial scaffolds made with type I collagen helped maintain implanted cells, and surrounding tissue reactions were rare. Our findings indicate that type I collagen artificial scaffolds can be considered as a possible implantable biomaterial.

Two differentially structured collagen scaffolds for potential urinary bladder augmentation: proof of concept study in a Göttingen minipig model.

PubMed

Leonhäuser, Dorothea; Stollenwerk, Katja; Seifarth, Volker; Zraik, Isabella M; Vogt, Michael; Srinivasan, Pramod K; Tolba, Rene H; Grosse, Joachim O

2017-01-04

The repair of urinary bladder tissue is a necessity for tissue loss due to cancer, trauma, or congenital abnormalities. Use of intestinal tissue is still the gold standard in the urological clinic, which leads to new problems and dysfunctions like mucus production, stone formation, and finally malignancies. Therefore, the use of artificial, biologically derived materials is a promising step towards the augmentation of this specialised tissue. The aim of this study was to investigate potential bladder wall repair by two collagen scaffold prototypes, OptiMaix 2D and 3D, naïve and seeded with autologous vesical cells, as potential bladder wall substitute material in a large animal model. Six Göttingen minipigs underwent cystoplastic surgery for tissue biopsy and cell isolation followed by implantation of unseeded scaffolds. Six weeks after the first operation, scaffolds seeded with the tissue cultured autologous urothelial and detrusor smooth muscle cells were implanted into the bladder together with additional unseeded scaffolds for comparison. Cystography and bladder ultrasound were performed to demonstrate structural integrity and as leakage test of the implantation sites. Eighteen, 22, and 32 weeks after the first operation, two minipigs respectively were sacrificed and the urinary tract was examined via different (immunohistochemical) staining procedures and the usage of two-photon laser scanning microscopy. Both collagen scaffold prototypes in vivo had good ingrowth capacity into the bladder wall including a quick lining with urothelial cells. The ingrowth of detrusor muscle tissue, along with the degradation of the scaffolds, could also be observed throughout the study period. We could show that the investigated collagen scaffolds OptiMaix 2D and 3D are a potential material for bladder wall substitution. The material has good biocompatible properties, shows a good cell growth of autologous cells in vitro, and a good integration into the present bladder tissue in vivo.

A Comparison of Exogenous Labels for the Histological Identification of Transplanted Neural Stem Cells

PubMed Central

Nicholls, Francesca J.; Liu, Jessie R.; Modo, Michel

2017-01-01

The interpretation of cell transplantation experiments is often dependent on the presence of an exogenous label for the identification of implanted cells. The exogenous labels Hoechst 33342, 5-bromo-2′-deoxyuridine (BrdU), PKH26, and Qtracker were compared for their labeling efficiency, cellular effects, and reliability to identify a human neural stem cell (hNSC) line implanted intracerebrally into the rat brain. Hoechst 33342 (2 mg/ml) exhibited a delayed cytotoxicity that killed all cells within 7 days. This label was hence not progressed to in vivo studies. PKH26 (5 μM), Qtracker (15 nM), and BrdU (0.2 μM) labeled 100% of the cell population at day 1, although BrdU labeling declined by day 7. BrdU and Qtracker exerted effects on proliferation and differentiation. PKH26 reduced viability and proliferation at day 1, but this normalized by day 7. In an in vitro coculture assay, all labels transferred to unlabeled cells. After transplantation, the reliability of exogenous labels was assessed against the gold standard of a human-specific nuclear antigen (HNA) antibody. BrdU, PKH26, and Qtracker resulted in a very small proportion (<2%) of false positives, but a significant amount of false negatives (~30%), with little change between 1 and 7 days. Exogenous labels can therefore be reliable to identify transplanted cells without exerting major cellular effects, but validation is required. The interpretation of cell transplantation experiments should be presented in the context of the label's limitations. PMID:27938486

Repairing the vibratory vocal fold.

PubMed

Long, Jennifer L

2018-01-01

A vibratory vocal fold replacement would introduce a new treatment paradigm for structural vocal fold diseases such as scarring and lamina propria loss. This work implants a tissue-engineered replacement for vocal fold lamina propria and epithelium in rabbits and compares histology and function to injured controls and orthotopic transplants. Hypotheses were that the cell-based implant would engraft and control the wound response, reducing fibrosis and restoring vibration. Translational research. Rabbit adipose-derived mesenchymal stem cells (ASC) were embedded within a three-dimensional fibrin gel, forming the cell-based outer vocal fold replacement (COVR). Sixteen rabbits underwent unilateral resection of vocal fold epithelium and lamina propria, as well as reconstruction with one of three treatments: fibrin glue alone with healing by secondary intention, replantation of autologous resected vocal fold cover, or COVR implantation. After 4 weeks, larynges were examined histologically and with phonation. Fifteen rabbits survived. All tissues incorporated well after implantation. After 1 month, both graft types improved histology and vibration relative to injured controls. Extracellular matrix (ECM) of the replanted mucosa was disrupted, and ECM of the COVR implants remained immature. Immune reaction was evident when male cells were implanted into female rabbits. Best histologic and short-term vibratory outcomes were achieved with COVR implants containing male cells implanted into male rabbits. Vocal fold cover replacement with a stem cell-based tissue-engineered construct is feasible and beneficial in acute rabbit implantation. Wound-modifying behavior of the COVR implant is judged to be an important factor in preventing fibrosis. NA. Laryngoscope, 128:153-159, 2018. © 2017 The American Laryngological, Rhinological and Otological Society, Inc.

Hollow fiber: a biophotonic implant for live cells

NASA Astrophysics Data System (ADS)

Silvestre, Oscar F.; Holton, Mark D.; Summers, Huw D.; Smith, Paul J.; Errington, Rachel J.

2009-02-01

The technical objective of this study has been to design, build and validate biocompatible hollow fiber implants based on fluorescence with integrated biophotonics components to enable in fiber kinetic cell based assays. A human osteosarcoma in vitro cell model fiber system has been established with validation studies to determine in fiber cell growth, cell cycle analysis and organization in normal and drug treated conditions. The rationale for implant development have focused on developing benchmark concepts in standard monolayer tissue culture followed by the development of in vitro hollow fiber designs; encompassing imaging with and without integrated biophotonics. Furthermore the effect of introducing targetable biosensors into the encapsulated tumor implant such as quantum dots for informing new detection readouts and possible implant designs have been evaluated. A preliminary micro/macro imaging approach has been undertaken, that could provide a mean to track distinct morphological changes in cells growing in a 3D matrix within the fiber which affect the light scattering properties of the implant. Parallel engineering studies have showed the influence of the optical properties of the fiber polymer wall in all imaging modes. Taken all together, we show the basic foundation and the opportunities for multi-modal imaging within an in vitro implant format.

Implanted neural progenitor cells regulate glial reaction to brain injury and establish gap junctions with host glial cells.

PubMed

Talaverón, Rocío; Matarredona, Esperanza R; de la Cruz, Rosa R; Macías, David; Gálvez, Victoria; Pastor, Angel M

2014-04-01

Transplantation of neural stem/progenitor cells (NPCs) in the lesioned brain is able to restore morphological and physiological alterations induced by different injuries. The local microenvironment created at the site of grafting and the communication between grafted and host cells are crucial in the beneficial effects attributed to the NPC implants. We have previously described that NPC transplantation in an animal model of central axotomy restores firing properties and synaptic coverage of lesioned neurons and modulates their trophic factor content. In this study, we aim to explore anatomical relationships between implanted NPCs and host glia that might account for the implant-induced neuroprotective effects. Postnatal rat subventricular zone NPCs were isolated and grafted in adult rats after transection of the medial longitudinal fascicle. Brains were removed and analyzed eight weeks later. Immunohistochemistry for different glial markers revealed that NPC-grafted animals displayed significantly greater microglial activation than animals that received only vehicle injections. Implanted NPCs were located in close apposition to activated microglia and reactive astrocytes. The gap junction protein connexin43 was present in NPCs and glial cells at the lesion site and was often found interposed within adjacent implanted and glial cells. Gap junctions were identified between implanted NPCs and host astrocytes and less frequently between NPCs and microglia. Our results show that implanted NPCs modulate the glial reaction to lesion and establish the possibility of communication through gap junctions between grafted and host glial cells which might be involved in the restorative effects of NPC implants. Copyright © 2014 Wiley Periodicals, Inc.

Cytoskeletal stiffness, friction, and fluidity of cancer cell lines with different metastatic potential.

PubMed

Coughlin, Mark F; Bielenberg, Diane R; Lenormand, Guillaume; Marinkovic, Marina; Waghorne, Carol G; Zetter, Bruce R; Fredberg, Jeffrey J

2013-03-01

We quantified mechanical properties of cancer cells differing in metastatic potential. These cells included normal and H-ras-transformed NIH3T3 fibroblast cells, normal and oncoprotein-overexpressing MCF10A breast cancer cells, and weakly and strongly metastatic cancer cell line pairs originating from human cancers of the skin (A375P and A375SM cells), kidney (SN12C and SN12PM6 cells), prostate (PC3M and PC3MLN4 cells), and bladder (253J and 253JB5 cells). Using magnetic twisting cytometry, cytoskeletal stiffness (g') and internal friction (g″) were measured over a wide frequency range. The dependencies of g' and g″ upon frequency were used to determine the power law exponent x which is a direct measure of cytoskeletal fluidity and quantifies where the cytoskeleton resides along the spectrum of solid-like (x = 1) to fluid-like (x = 2) states. Cytoskeletal fluidity x increased following transformation by H-ras oncogene expression in NIH3T3 cells, overexpression of ErbB2 and 14-3-3-ζ in MCF10A cells, and implantation and growth of PC3M and 253J cells in the prostate and bladder, respectively. Each of these perturbations that had previously been shown to enhance cancer cell motility and invasion are shown here to shift the cytoskeleton towards a more fluid-like state. In contrast, strongly metastatic A375SM and SN12PM6 cells that disseminate by lodging in the microcirculation of peripheral organs had smaller x than did their weakly metastatic cell line pairs A375P and SN12C, respectively. Thus, enhanced hematological dissemination was associated with decreased x and a shift towards a more solid-like cytoskeleton. Taken together, these results are consistent with the notion that adaptations known to enhance metastatic ability in cancer cell lines define a spectrum of fluid-like versus solid-like states, and the position of the cancer cell within this spectrum may be a determinant of cancer progression.

Effect of low-energy hydrogen ion implantation on dendritic web silicon solar cells

NASA Technical Reports Server (NTRS)

Rohatgi, A.; Meier, D. L.; Rai-Choudhury, P.; Fonash, S. J.; Singh, R.

1986-01-01

The effect of a low-energy (0.4 keV), short-time (2-min), heavy-dose (10 to the 18th/sq cm) hydrogen ion implant on dendritic web silicon solar cells and material was investigated. Such an implant was observed to improve the cell open-circuit voltage and short-circuit current appreciably for a number of cells. In spite of the low implant energy, measurements of internal quantum efficiency indicate that it is the base of the cell, rather than the emitter, which benefits from the hydrogen implant. This is supported by the observation that the measured minority-carrier diffusion length in the base did not change when the emitter was removed. In some cases, a threefold increase of the base diffusion length was observed after implantation. The effects of the hydrogen implantation were not changed by a thermal stress test at 250 C for 111 h in nitrogen. It is speculated that hydrogen enters the bulk by traveling along dislocations, as proposed recently for edge-defined film-fed growth silicon ribbon.

Bone-Induced Chondroinduction in Sheep Jamshidi Biopsy Defects with and without Treatment by Subchondral Chitosan-Blood Implant: 1-Day, 3-Week, and 3-Month Repair.

PubMed

Bell, Angela D; Lascau-Coman, Viorica; Sun, Jun; Chen, Gaoping; Lowerison, Mark W; Hurtig, Mark B; Hoemann, Caroline D

2013-04-01

Delivery of chitosan to subchondral bone is a novel approach for augmented marrow stimulation. We evaluated the effect of 3 presolidified chitosan-blood implant formulations on osteochondral repair progression compared with untreated defects. In N = 5 adult sheep, six 2-mm diameter Jamshidi biopsy holes were created bilaterally in the medial femoral condyle and treated with presolidified chitosan-blood implant with fluorescent chitosan tracer (10 kDa, 40 kDa, or 150k Da chitosan, left knee) or left to bleed (untreated, right knee). Implant residency and osteochondral repair were assessed at 1 day (N = 1), 3 weeks (N = 2), or 3 months (N = 2) postoperative using fluorescence microscopy, histomorphometry, stereology, and micro-computed tomography. Chitosan implants were retained in 89% of treated Jamshidi holes up to 3 weeks postoperative. At 3 weeks, biopsy sites were variably covered by cartilage flow, and most bone holes contained cartilage flow fragments and heterogeneous granulation tissues with sparse leukocytes, stromal cells, and occasional adipocytes (volume density 1% to 3%). After 3 months of repair, most Jamshidi bone holes were deeper, remodeling at the edges, filled with angiogenic granulation tissue, and lined with variably sized chondrogenic foci fused to bone trabeculae or actively repairing bone plate. The 150-kDa chitosan implant elicited more subchondral cartilage formation compared with 40-kDa chitosan-treated and control defects (P < 0.05, N = 4). Treated defects contained more mineralized repair tissue than control defects at 3 months (P < 0.05, N = 12). Bone plate-induced chondroinduction is an articular cartilage repair mechanism. Jamshidi biopsy repair takes longer than 3 months and can be influenced by subchondral chitosan-blood implant.

Management of pseudophakic myopic anisometropic amblyopia with piggyback Visian® implantable collamer lens.

PubMed

Eissa, Sherif A

2017-03-01

To assess the outcomes of sulcus implantation of the Visian ® implantable collamer lens (ICL) to correct pseudophakic myopic anisometropic amblyopia with myopic shift and/or primary refractive overcorrection. Prospective case series enrolled 14 pseudophakic eyes of 14 patients, 5-9 years old, with history of cataract surgery and primary in the bag-intraocular lenses (IOL) implantation, followed by myopic shift and/or refractive overcorrection and anisometropic amblyopia of variable degrees. All cases had implantation of a piggyback ICL/toric ICL, to correct the myopia/myopic astigmatism. Preoperatively, we evaluated the uncorrected distance visual acuity (UCVA), corrected distance visual acuity (CDVA), manifest refraction spherical equivalent (MRSE), intraocular pressure (IOP) and endothelial cell density (ECD). We assessed the position and vaulting of the ICLs on slit lamp examination and confirmed by Scheimpflug tomography. Postoperative follow-up was at 1st week and 1, 3, 6, 9, 12, 18 and 24 months. Uncorrected distance visual acuity improved in all cases, and CDVA improved in 11 amblyopic eyes (2-4 lines). There was no evidence of interlenticular opacification (ILO) throughout the 2-year follow-up. Two cases were complicated with early postoperative acute elevation of IOP and were controlled with topical beta-blockers. Postoperative acute anterior uveitis occurred in six eyes and controlled by topical steroids. Implantable collamer lens (ICL) vault was measured using Pentacam, with mean value of 470 ± 238 μm. Sulcus implantation of the secondary piggyback ICL to correct unilateral pseudophakic myopic refractive error in children was safe, efficient, predictable and well tolerated in management of anisometropic amblyopia in all eyes. © 2016 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

Bone-Induced Chondroinduction in Sheep Jamshidi Biopsy Defects with and without Treatment by Subchondral Chitosan-Blood Implant

PubMed Central

Bell, Angela D.; Lascau-Coman, Viorica; Sun, Jun; Chen, Gaoping; Lowerison, Mark W.; Hurtig, Mark B.

2013-01-01

Objective: Delivery of chitosan to subchondral bone is a novel approach for augmented marrow stimulation. We evaluated the effect of 3 presolidified chitosan-blood implant formulations on osteochondral repair progression compared with untreated defects. Design: In N = 5 adult sheep, six 2-mm diameter Jamshidi biopsy holes were created bilaterally in the medial femoral condyle and treated with presolidified chitosan-blood implant with fluorescent chitosan tracer (10 kDa, 40 kDa, or 150k Da chitosan, left knee) or left to bleed (untreated, right knee). Implant residency and osteochondral repair were assessed at 1 day (N = 1), 3 weeks (N = 2), or 3 months (N = 2) postoperative using fluorescence microscopy, histomorphometry, stereology, and micro–computed tomography. Results: Chitosan implants were retained in 89% of treated Jamshidi holes up to 3 weeks postoperative. At 3 weeks, biopsy sites were variably covered by cartilage flow, and most bone holes contained cartilage flow fragments and heterogeneous granulation tissues with sparse leukocytes, stromal cells, and occasional adipocytes (volume density 1% to 3%). After 3 months of repair, most Jamshidi bone holes were deeper, remodeling at the edges, filled with angiogenic granulation tissue, and lined with variably sized chondrogenic foci fused to bone trabeculae or actively repairing bone plate. The 150-kDa chitosan implant elicited more subchondral cartilage formation compared with 40-kDa chitosan-treated and control defects (P < 0.05, N = 4). Treated defects contained more mineralized repair tissue than control defects at 3 months (P < 0.05, N = 12). Conclusion: Bone plate–induced chondroinduction is an articular cartilage repair mechanism. Jamshidi biopsy repair takes longer than 3 months and can be influenced by subchondral chitosan-blood implant. PMID:26069656

DOE Office of Scientific and Technical Information (OSTI.GOV)

Young, David L.; Nemeth, William; LaSalvia, Vincenzo

Here, we present progress to develop low-cost interdigitated back contact solar cells with pc-Si/SiO 2/c-Si passivated contacts formed by plasma immersion ion implantation (PIII). PIII is a lower-cost implantation technique than traditional beam line implantation due to its simpler design, lower operating costs, and ability to run high doses (1E14-1E18 cm -2) at low ion energies (20 eV-10 keV). These benefits make PIII ideal for high throughput production of patterned passivated contacts, where high-dose, low-energy implantations are made into thin (20-200 nm) a-Si layers instead of into the wafer itself. For this work symmetric passivated contact test structures (~100 nmmore » thick) grown on n-Cz wafers with pH3 PIII doping gave implied open circuit voltage (iV oc) values of 730 mV with J o values of 2 fA/cm 2. Samples doped with B 2H 6 gave iV oc values of 690 mV and J o values of 24 fA/cm 2, outperforming BF 3 doping, which gave iV oc values in the 660-680 mV range. Samples were further characterized by SIMS, photoluminescence, TEM, EELS, and post-metallization TLM to reveal micro- and macro-scopic structural, chemical and electrical information.« less

Integration of an Axcelis Optima HD Single Wafer High Current Implanter for p- and n-S/D Implants in an Existing Batch Implanter Production Line

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schmeide, Matthias; Kontratenko, Serguei; Krimbacher, Bernhard

2008-11-03

This paper is focused on the integration and qualification of an Axcelis Optima HD single wafer high current spot beam implanter in an existing 200 mm production line with different types of Axcelis batch implanters for high current applications. Both the design of the beamline and the beam shape are comparable between single wafer and batch high current spot beam implanters. In contrast to the single wafer high current ribbon beam implanter, energy contamination is not a concern for the considered spot beam tool because the drift mode can be used down to energies in the 2 keV region. Themore » most important difference between single wafer and batch high current implanters is the significantly higher dose rate and, therefore, the higher damage rate for the single wafer tool due to the different scanning architecture. The results of the integration of high dose implantations, mainly for p- and n-S/D formation, for DRAM 110 nm without pre-amorphization implantation (PAI), CMOS Logic from around 250 nm down to 90 nm without and with PAI, are presented and discussed. Dopant concentration profile analysis using SIMS was performed for different technologies and implantation conditions. The impurity activation was measured using sheet resistance and in some cases spreading resistance technique was applied. The amorphous layer thickness was measured using TEM. Finally, device data are presented in combination with dose, energy and beam current variations. The results have shown that the integration of implantation processes into crystalline structure without PAI is more complex and time consuming than implantations into amorphous layer where the damage difference due to the different dose rates is negligible.« less

Research on dental implant and its industrialization stage

NASA Astrophysics Data System (ADS)

Dongjoon, Yang; Sukyoung, Kim

2017-02-01

Bone cell attachment to Ti implant surfaces is the most concerned issue in the clinical implant dentistry. Many attempts to achieve the fast and strong integration between bone and implant have been tried in many ways, such as selection of materials (for example, Ti, ZrO2), shape design of implant (for example, soft tissue level, bone level, taped or conical, etc), and surface modification of implants (for example, roughed. coated, hybrid), etc. Among them, a major consideration is the surface design of dental implants. The surface with proper structural characteristics promotes or induces the desirable responses of cells and tissues. To obtain such surface which has desirable cell and tissue response, a variety of surface modification techniques has been developed and employed for many years. In this review, the method and trend of surface modification will be introduced and explained in terms of the surface topography and chemistry of dental implants.

Early fixation of cobalt-chromium based alloy surgical implants to bone using a tissue-engineering approach.

PubMed

Ogawa, Munehiro; Tohma, Yasuaki; Ohgushi, Hajime; Takakura, Yoshinori; Tanaka, Yasuhito

2012-01-01

To establish the methods of demonstrating early fixation of metal implants to bone, one side of a Cobalt-Chromium (CoCr) based alloy implant surface was seeded with rabbit marrow mesenchymal cells and the other side was left unseeded. The mesenchymal cells were further cultured in the presence of ascorbic acid, β-glycerophosphate and dexamethasone, resulting in the appearance of osteoblasts and bone matrix on the implant surface. Thus, we succeeded in generating tissue-engineered bone on one side of the CoCr implant. The CoCr implants were then implanted in rabbit bone defects. Three weeks after the implantation, evaluations of mechanical test, undecalcified histological section and electron microscope analysis were performed. Histological and electron microscope images of the tissue engineered surface exhibited abundant new bone formation. However, newly formed bone tissue was difficult to detect on the side without cell seeding. In the mechanical test, the mean values of pull-out forces were 77.15 N and 44.94 N for the tissue-engineered and non-cell-seeded surfaces, respectively. These findings indicate early bone fixation of the tissue-engineered CoCr surface just three weeks after implantation.

Early Fixation of Cobalt-Chromium Based Alloy Surgical Implants to Bone Using a Tissue-engineering Approach

PubMed Central

Ogawa, Munehiro; Tohma, Yasuaki; Ohgushi, Hajime; Takakura, Yoshinori; Tanaka, Yasuhito

2012-01-01

To establish the methods of demonstrating early fixation of metal implants to bone, one side of a Cobalt-Chromium (CoCr) based alloy implant surface was seeded with rabbit marrow mesenchymal cells and the other side was left unseeded. The mesenchymal cells were further cultured in the presence of ascorbic acid, β-glycerophosphate and dexamethasone, resulting in the appearance of osteoblasts and bone matrix on the implant surface. Thus, we succeeded in generating tissue-engineered bone on one side of the CoCr implant. The CoCr implants were then implanted in rabbit bone defects. Three weeks after the implantation, evaluations of mechanical test, undecalcified histological section and electron microscope analysis were performed. Histological and electron microscope images of the tissue engineered surface exhibited abundant new bone formation. However, newly formed bone tissue was difficult to detect on the side without cell seeding. In the mechanical test, the mean values of pull-out forces were 77.15 N and 44.94 N for the tissue-engineered and non-cell-seeded surfaces, respectively. These findings indicate early bone fixation of the tissue-engineered CoCr surface just three weeks after implantation. PMID:22754313

Modified model of VX2 tumor overexpressing vascular endothelial growth factor.

PubMed

Pascale, Florentina; Ghegediban, Saida-Homayra; Bonneau, Michel; Bedouet, Laurent; Namur, Julien; Verret, Valentin; Schwartz-Cornil, Isabelle; Wassef, Michel; Laurent, Alexandre

2012-06-01

To determine whether upregulated expression of vascular endothelial growth factor (VEGF) in VX2 cells can increase vessel density (VD) and reduce tumor necrosis. The VX2 cell line was transfected with expression vectors containing cDNA for rabbit VEGF. Stable clones producing rabbit VEGF (VEGF-VX2) were selected. VEGF-VX2 cells (n = 5 rabbits) or nontransfected VX2 cells (controls; n = 5 rabbits) were implanted into leg muscle of 10 rabbits. The animals were sacrificed at day 21. Tumor volume, percentage of necrosis, VD, and VEGF concentration in tumor protein extract were quantified. Overexpression of VEGF by VX2 cells augmented tumor implantation efficiency 100% and favored cyst formation. The tumor volume was significantly larger for VEGF-VX2 transfected tumors versus controls (P = .0143). Overexpression of VEGF in VX2 cells significantly increased the VD of the tumors (P = .0138). The percentage of necrosis was reduced in VEGF-VX2 tumors versus controls (19.5% vs 38.5 %; P = .002). VEGF concentration in VEGF-VX2 tumors was significantly higher than in control tumors (P = .041) and was correlated with tumor volume (ρ = .883, P = .012). The overexpression of VEGF increased tumor growth and vascularization, favored cyst formation, and reduced tumor necrosis. This new phenotype of the VX2 tumor may offer some advantages over classic models of VX2 tumor for evaluating anticancer therapies. Copyright © 2012 SIR. Published by Elsevier Inc. All rights reserved.

Ovarian Cancer Is an Imported Disease: Fact or Fiction?

PubMed Central

Kuhn, Elisabetta; Kurman, Robert J.

2012-01-01

The cell of origin of ovarian cancer has been long debated. The current paradigm is that epithelial ovarian cancer (EOC) arises from the ovarian surface epithelium (OSE). OSE is composed of flat, nondescript cells more closely resembling the mesothelium lining the peritoneal cavity, with which it is continuous, rather than the various histologic types of ovarian carcinoma (serous, endometrioid, and clear cell carcinoma), which have a Müllerian phenotype. Accordingly, it has been argued that the OSE undergoes a process termed “metaplasia” to account for this profound morphologic transformation. Recent molecular and clinicopathologic studies not only have failed to support this hypothesis but also have provided evidence that EOC stems from Müllerian-derived extraovarian cells that involve the ovary secondarily, thereby calling into question the very existence of primary EOC. This new model of ovarian carcinogenesis proposes that fallopian tube epithelium (benign or malignant) implants on the ovary to give rise to both high-grade and low-grade serous carcinomas, and that endometrial tissue implants on the ovary and produces endometriosis, which can undergo malignant transformation into endometrioid and clear cell carcinoma. Thus, ultimately EOC is not ovarian in origin but rather is secondary, and it is logical to conclude that the only true primary ovarian neoplasms are germ cell and gonadal stromal tumors analogous to tumors in the testis. If this new model is confirmed, it has profound implications for the early detection and treatment of “ovarian cancer.” PMID:22506137

Probing the tumor microenvironment: collection and induction

NASA Astrophysics Data System (ADS)

Williams, James K.; Padgen, Michael R.; Wang, Yarong; Entenberg, David; Gertler, Frank; Condeelis, John S.; Castracane, James

2012-03-01

The Nano Intravital Device, or NANIVID, is under development as an optically transparent, implantable tool to study the tumor microenvironment. Two etched glass substrates are sealed using a thin polymer membrane to create a reservoir with a single outlet. This reservoir is loaded with a hydrogel blend that contains growth factors or other chemicals to be delivered to the tumor microenvironment. When the device is implanted in the tumor, the hydrogel will swell and release these entrapped molecules, forming a gradient. Validation of the device has been performed in vitro using epidermal growth factor (EGF) and MenaINV, a highly invasive, rat mammary adenocarcinoma cell line. In both 2-D and 3-D environments, cells migrated toward the gradient of EGF released from the device. The chorioallantoic membrane (CAM) of White Leghorn chicken eggs is being utilized to grow xenograft tumors that will be used for ex vivo cell collection. Device optimization is being performed for in vivo use as a tool to collect the invasive cell population. Preliminary cell collection experiments in vivo were performed using a mouse model of breast cancer. As a second application, the device is being explored as a delivery vehicle for chemicals that induce controlled changes in the tumor microenvironment. H2O2 was loaded in the device and generated intracellular reactive oxygen species (ROS) in cells near the device outlet. In the future, other induction targets will be explored, including hypoglycemia and the manipulation of extracellular matrix stiffness.

Biology of teeth and implants: Host factors - pathology, regeneration, and the role of stem cells.

PubMed

Eggert, F-Michael; Levin, Liran

2018-01-01

In chronic periodontitis and peri-implantitis, cells of the innate and adaptive immune systems are involved directly in the lesions within the tissues of the patient. Absence of a periodontal ligament around implants does not prevent a biologic process similar to that of periodontitis from affecting osseointegration. Our first focus is on factors in the biology of individuals that are responsible for the susceptibility of such individuals to chronic periodontitis and to peri-implantitis. Genetic factors are of significant importance in susceptibility to these diseases. Genetic factors of the host affect the composition of the oral microbiome in the same manner that they influence other microbiomes, such as those of the intestines and of the lungs. Our second focus is on the central role of stem cells in tissue regeneration, in the functioning of innate and adaptive immune systems, and in metabolism of bone. Epithelial cell rests of Malassez (ERM) are stem cells of epithelial origin that maintain the periodontal ligament as well as the cementum and alveolar bone associated with the ligament. The tissue niche within which ERM are found extends into the supracrestal areas of collagen fiber-containing tissues of the gingivae above the bony alveolar crest. Maintenance and regeneration of all periodontal tissues involves the activity of a variety of stem cells. The success of dental implants indicates that important groups of stem cells in the periodontium are active to enable that biologic success. Successful replantation of avulsed teeth and auto-transplantation of teeth is comparable to placing dental implants, and so must also involve periodontal stem cells. Biology of teeth and biology of implants represents the biology of the various stem cells that inhabit specialized niches within the periodontal tissues. Diverse biologic processes must function together successfully to maintain periodontal health. Osseointegration of dental implants does not involve formation of cementum or collagen fibers inserted into cementum - indicating that some stem cells are not active around dental implants or their niches are not available. Investigation of these similarities and differences between teeth and implants will help to develop a better understanding of the biology and physiologic functioning of the periodontium.

Behaviour of nitinol in osteoblast-like ROS-17 cell cultures.

PubMed

Kapanen, A; Ilvesaro, J; Danilov, A; Ryhänen, J; Lehenkari, P; Tuukkanen, J

2002-02-01

Nickel titanium shape memory metal alloy Nitinol (NiTi) has been used in dental wares and in gastrointestinal surgery. Nitinol is a promising implant material in orthopedics, but its biocompatibility, especially in long-term implantation is not confirmed yet. We studied Nitinol's effect on a cell culture model. Comparisons to stainless steel, pure titanium and pure nickel were performed. The effects of Nitinol on cell death rate, the apoptosis rate and the formation of local contacts were studied on rat osteosarcoma cell line ROS-17 in 48-h cultures. The cell death rate was assessed with combined calcein-ethidium-homodimer labelling. The amount of dead cells 1000 cells were as follows: four in the NiTi, 21 in the Stst, 4.8 in the Ti and 51 in the Ni group. In the NiTi and Ti groups, the number of dead cells was significantly lower (p < or = 0.01) than in Ni group. The rate of apoptosis was detected with TUNEL-assay. The assay results were: 1.93 apoptotic cells 1000 cells in the NiTi, 1.1 in the Stst, 2.98 in the Ti and 0.62 in the Ni group. A comparison of these two results shows that 48% of the dead cells were apoptotic in the NiTi, 56.6 in the Stst, 62% in the Ti and only 1.8% in the Ni group. The focal contacts were stained with a paxillin antibody and counted. There were marked differences in the number of focal contacts per unit area compared to NiTi (774 focal contacts): 335 in Stst (p < or = 0.01), 462 in Ti (p < or = 0.01) and 261 in Ni (p < or = 0.005). Our results show that NiTi is well tolerated by the osteoblastic type ROS-17 cells.

CD146/MCAM defines functionality of human bone marrow stromal stem cell populations.

PubMed

Harkness, Linda; Zaher, Walid; Ditzel, Nicholas; Isa, Adiba; Kassem, Moustapha

2016-01-11

Identification of surface markers for prospective isolation of functionally homogenous populations of human skeletal (stromal, mesenchymal) stem cells (hMSCs) is highly relevant for cell therapy protocols. Thus, we examined the possible use of CD146 to subtype a heterogeneous hMSC population. Using flow cytometry and cell sorting, we isolated two distinct hMSC-CD146(+) and hMSC-CD146(-) cell populations from the telomerized human bone marrow-derived stromal cell line (hMSC-TERT). Cells were examined for differences in their size, shape and texture by using high-content analysis and additionally for their ability to differentiate toward osteogenesis in vitro and form bone in vivo, and their migrational ability in vivo and in vitro was investigated. In vitro, the two cell populations exhibited similar growth rate and differentiation capacity to osteoblasts and adipocytes on the basis of gene expression and protein production of lineage-specific markers. In vivo, hMSC-CD146(+) and hMSC-CD146(-) cells formed bone and bone marrow organ when implanted subcutaneously in immune-deficient mice. Bone was enriched in hMSC-CD146(-) cells (12.6 % versus 8.1 %) and bone marrow elements enriched in implants containing hMSC-CD146(+) cells (0.5 % versus 0.05 %). hMSC-CD146(+) cells exhibited greater chemotactic attraction in a transwell migration assay and, when injected intravenously into immune-deficient mice following closed femoral fracture, exhibited wider tissue distribution and significantly increased migration ability as demonstrated by bioluminescence imaging. Our studies demonstrate that CD146 defines a subpopulation of hMSCs capable of bone formation and in vivo trans-endothelial migration and thus represents a population of hMSCs suitable for use in clinical protocols of bone tissue regeneration.

In Vitro Evaluation of Cell Compatibility of Dental Cements Used with Titanium Implant Components.

PubMed

Marvin, Jason C; Gallegos, Silvia I; Parsaei, Shaida; Rodrigues, Danieli C

2018-03-09

To evaluate the biocompatibility of five dental cement compositions after directly exposing human gingival fibroblast (HGF) and MC3T3-E1 preosteoblast cells to cement alone and cement applied on commercially pure titanium (cpTi) specimens. Nanostructurally integrated bioceramic (NIB), resin (R), resin-modified glass ionomer (RMGIC), zinc oxide eugenol (ZOE), and zinc phosphate (ZP) compositions were prepared according to the respective manufacturer's instructions. Samples were prepared in cylindrical Teflon molds or applied over the entire surface of polished cpTi discs. All samples were cured for 0.5, 1, 12, or 24 hours post-mixing. Direct contact testing was conducted according to ISO 10993 by seeding 6-well plates at 350,000 cells/well. Plates were incubated at 37°C in a humidified atmosphere with 5% CO 2 for 24 hours before individually plating samples and cpTi control discs. Plates were then incubated for an additional 24 hours. Microtetrazolium (MTT) cell viability assays were used to measure sample cytotoxicity. For samples that cured for 24 hours prior to direct contact exposure, only NIB and ZP cements when cemented on cpTi demonstrated cell viability percentages above the minimum biocompatibility requirement (≥70%) for both the investigative cell lines. R, RMGIC, and ZOE cements exhibited moderate to severe cytotoxic effects on both cell lines in direct contact and when cemented on cpTi specimens. For HGF cells, ZOE cemented-cpTi specimens exhibited significantly decreased cytotoxicity, whereas RMGIC cemented-cpTi specimens exhibited significantly increased cytotoxicity. Despite previous studies that showed enhanced cpTi corrosion activity for fluoride-containing compositions (NIB and ZP), there was no significant difference in cytotoxicity between cement alone and cemented-cpTi. In general, the MC3T3-E1 preosteoblast cells were more sensitive than HGF cells to cement composition. Ultimately, cement composition played a significant role in maintaining host cell compatibility. Results of this work help illustrate the impact of different cement formulations on host cell health and emphasize the need for understanding material properties when selecting certain formulations of dental cements, which can ultimately influence the survival of dental implant systems. © 2018 by the American College of Prosthodontists.

Improved adductor function after canine recurrent laryngeal nerve injury and repair using muscle progenitor cells.

PubMed

Paniello, Randal C; Brookes, Sarah; Bhatt, Neel K; Bijangi-Vishehsaraei, Khadijeh; Zhang, Hongji; Halum, Stacey

2017-12-08

Muscle progenitor cells (MPCs) can be isolated from muscle samples and grown to a critical mass in culture. They have been shown to survive and integrate when implanted into rat laryngeal muscles. In this study, the ability of MPC implants to enhance adductor function of reinnervated thyroarytenoid muscles was tested in a canine model. Animal study. Sternocleidomastoid muscle samples were harvested from three canines. Muscle progenitor cells were isolated and cultured to 10 7 cells over 4 to 5 weeks, then implanted into right thyroarytenoid muscles after ipsilateral recurrent laryngeal nerve transection and repair. The left sides underwent the same nerve injury, but no cells were implanted. Laryngeal adductor force was measured pretreatment and again 6 months later, and the muscles were harvested for histology. Muscle progenitor cells were successfully cultured from all dogs. Laryngeal adductor force measurements averaged 60% of their baseline pretreatment values in nonimplanted controls, 98% after implantation with MPCs, and 128% after implantation with motor endplate-enhanced MPCs. Histology confirmed that the implanted MPCs survived, became integrated into thyroarytenoid muscle fibers, and were in close contact with nerve endings, suggesting functional innervation. Muscle progenitor cells were shown to significantly enhance adductor function in this pilot canine study. Patient-specific MPC implantation could potentially be used to improve laryngeal function in patients with vocal fold paresis/paralysis, atrophy, and other conditions. Further experiments are planned. NA. Laryngoscope, 2017. © 2017 The American Laryngological, Rhinological and Otological Society, Inc.

Multilayer cell-seeded polymer nanofiber constructs for soft-tissue reconstruction.

PubMed

Barker, Daniel A; Bowers, Daniel T; Hughley, Brian; Chance, Elizabeth W; Klembczyk, Kevin J; Brayman, Kenneth L; Park, Stephen S; Botchwey, Edward A

2013-09-01

Cell seeding throughout the thickness of a nanofiber construct allows for patient-specific implant alternatives with long-lasting effects, earlier integration, and reduced inflammation when compared with traditional implants. Cell seeding may improve implant integration with host tissue; however, the effect of cell seeding on thick nanofiber constructs has not been studied. To use a novel cell-preseeded nanofiber tissue engineering technique to create a 3-dimensional biocompatible implant alternative to decellularized extracellular matrix. Animal study with mammalian cell culture to study tissue engineered scaffolds. Academic research laboratory. Thirty-six Sprague-Dawley rats. The rats each received 4 implant types. The grafts included rat primary (enhanced green fluorescent protein-positive [eGFP+]) fibroblast-seeded polycaprolactone (PCL)/collagen nanofiber scaffold, PCL/collagen cell-free nanofiber scaffold, acellular human cadaveric dermis (AlloDerm), and acellular porcine dermis (ENDURAGen). Rats were monitored postoperatively and received enrofloxacin in the drinking water for 4 days prophylactically and buprenorphine (0.2-0.5 mg/kg administered subcutaneously twice a day postoperatively for pain for 48 hours). The viability of NIH/3T3 fibroblasts cultured on PCL electrospun nanofibers was evaluated using fluorescence microscopy. Soft-tissue remodeling was examined histologically and with novel ex vivo volume determinations of implants using micro-computed tomography of cell-seeded implants relative to nanofibers without cells and commonly used dermal grafts of porcine and human origin (ENDURAGen and AlloDerm, respectively). The fate and distribution of eGFP+ seeded donor fibroblasts were assessed using immunohistochemistry. Fibroblasts migrated across nanofiber layers within 12 hours and remained viable on a single layer for up to 14 days. Scanning electron microscopy confirmed a nanoscale structure with a mean (SD) diameter of 158 (72) nm. Low extrusion rates demonstrated the excellent biocompatibility in vivo. Histological examination of the scaffolds demonstrated minimal inflammation. Cell seeding encouraged rapid vascularization of the nanofiber implants. Cells of donor origin (eGFP+) declined with the duration of implantation. Implant volume was not significantly affected for up to 8 weeks by the preseeding of cells (P > .05). Polymer nanofiber-based scaffolds mimic natural extracellular matrix. Preseeding the nanofiber construct with cells improved vascularization without notable effects on volume. An effect of cell preseeding on scaffold vascularization was evident beyond the presence of preseeded cells. This 3-dimensional, multilayer method of cell seeding throughout a 1-mm-thick construct is simple and feasible for clinical application. Further development of this technique may affect the clinical practice of facial plastic and reconstructive surgeons.

Optimization of Cell Adhesion on Mg Based Implant Materials by Pre-Incubation under Cell Culture Conditions

PubMed Central

Willumeit, Regine; Möhring, Anneke; Feyerabend, Frank

2014-01-01

Magnesium based implants could revolutionize applications where orthopedic implants such as nails, screws or bone plates are used because they are load bearing and degrade over time. This prevents a second surgery to remove conventional implants. To improve the biocompatibility we studied here if and for how long a pre-incubation of the material under cell culture conditions is favorable for cell attachment and proliferation. For two materials, Mg and Mg10Gd1Nd, we could show that 6 h pre-incubation are already enough to form a natural protective layer suitable for cell culture. PMID:24857908

Optimization of cell adhesion on mg based implant materials by pre-incubation under cell culture conditions.

PubMed

Willumeit, Regine; Möhring, Anneke; Feyerabend, Frank

2014-05-05

Magnesium based implants could revolutionize applications where orthopedic implants such as nails, screws or bone plates are used because they are load bearing and degrade over time. This prevents a second surgery to remove conventional implants. To improve the biocompatibility we studied here if and for how long a pre-incubation of the material under cell culture conditions is favorable for cell attachment and proliferation. For two materials, Mg and Mg10Gd1Nd, we could show that 6 h pre-incubation are already enough to form a natural protective layer suitable for cell culture.

In Vivo Imaging and Tracking of Technetium-99m Labeled Bone Marrow Mesenchymal Stem Cells in Equine Tendinopathy

PubMed Central

Dudhia, Jayesh; Becerra, Patricia; Valdés, Miguel A.; Neves, Francisco; Hartman, Neil G.; Smith, Roger K.W.

2015-01-01

Recent advances in the application of bone marrow mesenchymal stem cells (BMMSC) for the treatment of tendon and ligament injuries in the horse suggest improved outcome measures in both experimental and clinical studies. Although the BMMSC are implanted into the tendon lesion in large numbers (usually 10 - 20 million cells), only a relatively small number survive (<10%) although these can persist for up to 5 months after implantation. This appears to be a common observation in other species where BMMSC have been implanted into other tissues and it is important to understand when this loss occurs, how many survive the initial implantation process and whether the cells are cleared into other organs. Tracking the fate of the cells can be achieved by radiolabeling the BMMSC prior to implantation which allows non-invasive in vivo imaging of cell location and quantification of cell numbers. This protocol describes a cell labeling procedure that uses Technetium-99m (Tc-99m), and tracking of these cells following implantation into injured flexor tendons in horses. Tc-99m is a short-lived (t1/2 of 6.01 hr) isotope that emits gamma rays and can be internalized by cells in the presence of the lipophilic compound hexamethylpropyleneamine oxime (HMPAO). These properties make it ideal for use in nuclear medicine clinics for the diagnosis of many different diseases. The fate of the labeled cells can be followed in the short term (up to 36 hr) by gamma scintigraphy to quantify both the number of cells retained in the lesion and distribution of the cells into lungs, thyroid and other organs. This technique is adapted from the labeling of blood leukocytes and could be utilized to image implanted BMMSC in other organs. PMID:26709915

Development of pulsed processes for the manufacture of solar cells

NASA Technical Reports Server (NTRS)

Minnucci, J. A.

1979-01-01

Low-energy ion implantation processes for the automated production of silicon solar cells were investigated. Phosphorus ions at an energy of 10 keV and dose of 2 x 10 to the 15th power/sq cm were implanted in silicon solar cells to produce junctions, while boron ions at 25 keV and 5 x 10 to the 15th power were implanted in the cells to produce effective back surface fields. An ion implantation facility with a beam current up to 4 mA and a production throughput of 300 wafers per hour was designed and installed. A design was prepared for a 100 mA, automated implanter with a production capacity of 100 MW sub e/sq cm per year. Two process sequences were developed which employ ion implantation and furnace or pulse annealing. A computer program was used to determine costs for junction formation by ion implantation and various furnace annealing cycles to demonstrate cost effectiveness of these methods.

Preventing neuronal damage and inflammation in vivo during cortical microelectrode implantation through the use of Poloxamer P-188

NASA Astrophysics Data System (ADS)

Misra, A.; Kondaveeti, P.; Nissanov, J.; Barbee, K.; Shewokis, P.; Rioux, L.; Moxon, K. A.

2013-02-01

Objective. The aim of this study was to test the efficacy of Poloxamer P188 to reduce cell death and immune response associated with mechanical trauma to cells during implantation of a chronic recording electrode. Approach. Ceramic multi-site recording electrodes were implanted bilaterally into 15 adult male Long-Evans rats. One of each pair was randomly assigned to receive a coating of Poloxamer while the other was treated with saline. The extent of neuron loss, and glial cell recruitment were characterized at 2, 4 and 6 weeks post-implantation by stereologic analysis. Main results. At 2 and 4 weeks post-implantation, Poloxamer-coated implants showed significantly fewer glial cells and more neurons in the peri-electrode space than controls; however, this significance was lost by 6 weeks. Significance. These findings are the first to suggest that Poloxamer has neuroprotective effects in vivo; however, at a fixed loading dose, these effects are limited to approximately 1 month post-implantation.

Expression of Pattern Recognition Receptors in Epithelial Cells Around Clinically Healthy Implants and Healthy Teeth.

PubMed

Calcaterra, Roberta; Di Girolamo, Michele; Mirisola, Concetta; Baggi, Luigi

2016-06-01

Gingival epithelial cells have a pivotal role in the recognition of microorganisms and damage-associated molecular pattern molecules and in the regulation of the immune response. The investigation of the behavior of Toll-like receptors (TLRs) and nucleotide oligomerization domain (NOD) like receptors (NLRs) around a healthy implant may help to address the first step of periimplantitis pathogenesis. To investigate by quantitative real-time polymerase chain reaction, the mRNA expressions of TLR2, TLR3, TLR4, TLR5, TLR6, TLR9, NOD1, NOD2, and NLRP3 from gingival epithelial cells of the sulcus around healthy implants and around healthy teeth. Two types of implant-abutment systems with tube-in-tube interface were tested. After 6 months of implant restoration, gingival epithelial cells were obtained from the gingival sulcus around the implants and around the adjacent teeth of 10 patients. Our results did not reach statistical significance among the mRNA expressions of TLR2, TLR3, TLR4, TLR5, TLR6, TLR9, NOD1, NOD2, and NLRP3 in epithelial cells around the implant versus around natural teeth. This study shows that the implant-abutment systems tested did not induce an immune response by the surrounding epithelial cells at 6 months since their positioning, as well as in the adjacent clincally healthy teeth.

In vivo dendritic cell depletion reduces breeding efficiency, affecting implantation and early placental development in mice.

PubMed

Krey, Gesa; Frank, Pierre; Shaikly, Valerie; Barrientos, Gabriela; Cordo-Russo, Rosalia; Ringel, Frauke; Moschansky, Petra; Chernukhin, Igor V; Metodiev, Metodi; Fernández, Nelson; Klapp, Burghard F; Arck, Petra C; Blois, Sandra M

2008-09-01

Implantation of mammalian embryos into their mother's uterus ensures optimal nourishment and protection throughout development. Complex molecular interactions characterize the implantation process, and an optimal synchronization of the components of this embryo-maternal dialogue is crucial for a successful reproductive outcome. In the present study, we investigated the role of dendritic cells (DC) during implantation process using a transgenic mouse system (DTRtg) that allows transient depletion of CD11c+ cells in vivo through administration of diphtheria toxin. We observed that DC depletion impairs the implantation process, resulting in a reduced breeding efficiency. Furthermore, the maturity of uterine natural killer cells at dendritic cell knockout (DCKO) implantation sites was affected as well; as demonstrated by decreased perforin expression and reduced numbers of periodic-acid-Schiff (PAS)-positive cells. This was accompanied by disarrangements in decidual vascular development. In the present study, we were also able to identify a novel DC-dependent protein, phosphatidylinositol transfer protein beta (PITPbeta), involved in implantation and trophoblast development using a proteomic approach. Indeed, DCKO mice exhibited substantial anomalies in placental development, including hypocellularity of the spongiotrophoblast and labyrinthine layers and reduced numbers of trophoblast giant cells. Giant cells also down-regulated their expression of two characteristic markers of trophoblast differentiation, placental lactogen 1 and proliferin. In view of these findings, dendritic cells emerge as possible modulators in the orchestration of events leading to the establishment and maintenance of pregnancy.

The high-mobility-group box protein SSRP1/T160 is essential for cell viability in day 3.5 mouse embryos.

PubMed

Cao, Shang; Bendall, Heather; Hicks, Geoffrey G; Nashabi, Abudi; Sakano, Hitoshi; Shinkai, Yoichi; Gariglio, Marisa; Oltz, Eugene M; Ruley, H Earl

2003-08-01

The high-mobility-group (HMG) SSRP1 protein is a member of a conserved chromatin-remodeling complex (FACT/DUF/CP) implicated in DNA replication, basal and regulated transcription, and DNA repair. To assist in the functional analysis of SSRP1, the Ssrp1 gene was targeted in murine embryonic stem cells, and the mutation was introduced into the germ line. Embryos homozygous for the targeted allele die soon after implantation, and preimplantation blastocysts are defective for cell outgrowth and/or survival in vitro. The Ssrp1 mutation was also crossed into a p53 null background without affecting growth and/or survival defects caused by loss of Ssrp1 function. Thus, Ssrp1 appears to encode nonredundant and p53-independent functions that are essential for cell viability.

Biocompatibility and anti-microbiological activity characterization of novel coatings for dental implants: A primer for non-biologists

NASA Astrophysics Data System (ADS)

Monsees, Thomas

2016-08-01

With regard to biocompatibility, the cardinal requirement for dental implants and other medical devices that are in long-term contact with tissue is that the material does not cause any adverse effect to the patient. To warrant stability and function of the implant, proper osseointegration is a further prerequisite. Cells interact with the implant surface as the interface between bulk material and biological tissue. Whereas structuring, deposition of a thin film or other modifications of the surface are crucial parameters in determining favorable adhesion of cells, corrosion of metal surfaces and release of ions can affect cell viability. Both parameters are usually tested using in vitro cytotoxicity and adhesion assays with bone or fibroblasts cells. For bioactive surface modifications, further tests should be considered for biocompatibility evaluation. Depending on the type of modification, this may include analysis of specific cell functions or the determination of antimicrobial activities. The latter is of special importance as bacteria and yeast present in the oral cavity can be introduced during the implantation process and this may lead to chronic infections and implant failure. An antimicrobial coating of the implant is a way to avoid that. This review describes the essential biocompatibility assays for evaluation of new implant materials required by ISO 10993 and also gives an overview on recent test methods for specific coatings of dental implants.

Regulation and Biological Significance of Formation of Osteoclasts and Foreign Body Giant Cells in an Extraskeletal Implantation Model

PubMed Central

Ahmed, Gazi Jased; Tatsukawa, Eri; Morishita, Kota; Shibata, Yasuaki; Suehiro, Fumio; Kamitakahara, Masanobu; Yokoi, Taishi; Koji, Takehiko; Umeda, Masahiro; Nishimura, Masahiro; Ikeda, Tohru

2016-01-01

The implantation of biomaterials induces a granulomatous reaction accompanied by foreign body giant cells (FBGCs). The characterization of multinucleated giant cells (MNGCs) around bone substitutes implanted in bone defects is more complicated because of healing with bone admixed with residual bone substitutes and their hybrid, and the appearance of two kinds of MNGCs, osteoclasts and FBGCs. Furthermore, the clinical significance of osteoclasts and FBGCs in the healing of implanted regions remains unclear. The aim of the present study was to characterize MNGCs around bone substitutes using an extraskeletal implantation model and evaluate the clinical significance of osteoclasts and FBGCs. Beta-tricalcium phosphate (β-TCP) granules were implanted into rat subcutaneous tissue with or without bone marrow mesenchymal cells (BMMCs), which include osteogenic progenitor cells. We also compared the biological significance of plasma and purified fibrin, which were used as binders for implants. Twelve weeks after implantation, osteogenesis was only detected in specimens implanted with BMMCs. The expression of two typical osteoclast markers, tartrate-resistant acid phosphatase (TRAP) and cathepsin-K (CTSK), was analyzed, and TRAP-positive and CTSK-positive osteoclasts were only detected beside bone. In contrast, most of the MNGCs in specimens without the implantation of BMMCs were FBGCs that were negative for TRAP, whereas the degradation of β-TCP was detected. In the region implanted with β-TCP granules with plasma, FBGCs tested positive for CTSK, and when β-TCP granules were implanted with purified fibrin, FBGCs tested negative for CTSK. These results showed that osteogenesis was essential to osteoclastogenesis, two kinds of FBGCs, CTSK-positive and CTSK-negative, were induced, and the expression of CTSK was plasma-dependent. In addition, the implantation of BMMCs was suggested to contribute to osteogenesis and the replacement of implanted β-TCP granules to bone. PMID:27462135

The use of morphokinetics as a predictor of embryo implantation.

PubMed

Meseguer, Marcos; Herrero, Javier; Tejera, Alberto; Hilligsøe, Karen Marie; Ramsing, Niels Birger; Remohí, Jose

2011-10-01

Time-lapse observation presents an opportunity for optimizing embryo selection based on morphological grading as well as providing novel kinetic parameters, which may further improve accurate selection of viable embryos. The objective of this retrospective study was to identify the morphokinetic parameters specific to embryos that were capable of implanting. In order to compare a large number of embryos, with minimal variation in culture conditions, we have used an automatic embryo monitoring system. Using a tri-gas IVF incubator with a built-in camera designed to automatically acquire images at defined time points, we have simultaneously monitored up to 72 individual embryos without removing the embryos from the controlled environment. Images were acquired every 15 min in five different focal planes for at least 64 h for each embryo. We have monitored the development of transferred embryos from 285 couples undergoing their first ICSI cycle. The total number of transferred embryos was 522, of which 247 either failed to implant or fully implanted, with full implantation meaning that all transferred embryos in a treatment implanted. A detailed retrospective analysis of cleavage times, blastomere size and multinucleation was made for the 247 transferred embryos with either failed or full implantation. We found that several parameters were significantly correlated with subsequent implantation (e.g. time of first and subsequent cleavages as well as the time between cleavages). The most predictive parameters were: (i) time of division to 5 cells, t5 (48.8-56.6 h after ICSI); (ii) time between division to 3 cells and subsequent division to 4 cells, s2 (≤ 0.76 h) and (iii) duration of cell cycle two, i.e. time between division to 2 cells and division to 3 cells, cc2 (≤ 11.9 h). We also observed aberrant behavior such as multinucleation at the 4 cell stage, uneven blastomere size at the 2 cell stage and abrupt cell division to three or more cells, which appeared to largely preclude implantation. The image acquisition and time-lapse analysis system makes it possible to determine exact timing of embryo cleavages in a clinical setting. We propose a multivariable model based on our findings to classify embryos according to their probability of implantation. The efficacy of this classification will be evaluated in a prospective randomized study that ultimately will determine if implantation rates can be improved by time-lapse analysis.

Toward angiogenesis of implanted bio-artificial liver using scaffolds with type I collagen and adipose tissue-derived stem cells

PubMed Central

Lee, Jae Geun; Bak, Seon Young; Nahm, Ji Hae; Lee, Sang Woo; Min, Seon Ok

2015-01-01

Backgrounds/Aims Stem cell therapies for liver disease are being studied by many researchers worldwide, but scientific evidence to demonstrate the endocrinologic effects of implanted cells is insufficient, and it is unknown whether implanted cells can function as liver cells. Achieving angiogenesis, arguably the most important characteristic of the liver, is known to be quite difficult, and no practical attempts have been made to achieve this outcome. We carried out this study to observe the possibility of angiogenesis of implanted bio-artificial liver using scaffolds. Methods This study used adipose tissue-derived stem cells that were collected from adult patients with liver diseases with conditions similar to the liver parenchyma. Specifically, microfilaments were used to create an artificial membrane and maintain the structure of an artificial organ. After scratching the stomach surface of severe combined immunocompromised (SCID) mice (n=4), artificial scaffolds with adipose tissue-derived stem cells and type I collagen were implanted. Expression levels of angiogenesis markers including vascular endothelial growth factor (VEGF), CD34, and CD105 were immunohistochemically assessed after 30 days. Results Grossly, the artificial scaffolds showed adhesion to the stomach and surrounding organs; however, there was no evidence of angiogenesis within the scaffolds; and VEGF, CD34, and CD105 expressions were not detected after 30 days. Conclusions Although implantation of cells into artificial scaffolds did not facilitate angiogenesis, the artificial scaffolds made with type I collagen helped maintain implanted cells, and surrounding tissue reactions were rare. Our findings indicate that type I collagen artificial scaffolds can be considered as a possible implantable biomaterial. PMID:26155277

The role of surface implant treatments on the biological behavior of SaOS-2 osteoblast-like cells. An in vitro comparative study.

PubMed

Conserva, Enrico; Menini, Maria; Ravera, Giambattista; Pera, Paolo

2013-08-01

The aim of this study was an in vitro comparison of osteoblast adhesion, proliferation and differentiation related to six dental implants with different surface characteristics, and to determine if the interaction between cells and implant is influenced by surface structure and chemical composition. Six types of implants were tested, presenting four different surface treatments: turned, sandblasted, acid-etched, anodized. The implant macro- and microstructure were analyzed using SEM, and the surface chemical composition was investigated using energy-dispersive X-ray analysis. SaOS-2 osteoblasts were used for the evaluation of cell adhesion and proliferation by SEM, and cell viability in contact with the various surfaces was determined using cytotoxicity MTT assays. Alkaline phosphatase (ALP) enzymatic activity in contact with the six surfaces was evaluated. Data relative to MTT assay and ALP activity were statistically analyzed using Kruskal-Wallis not parametric test and Nemenyi-Damico-Wolfe-Dunn post hoc test. All the implants tested supported cell adhesion, proliferation and differentiation, revealing neither organic contaminants nor cytotoxicity effects. The industrial treatments investigated changed the implant surface microscopic aspect and SaOS-2 cell morphology appeared to be influenced by the type of surface treatment at 6, 24, and 72 h of growth. SaOS-2 cells spread more rapidly on sandblasted surfaces. Turned surfaces showed the lowest cell proliferation at SEM observation. Sandblasted surfaces showed the greatest ALP activity values per cell, followed by turned surfaces (P < 0.05). On the base of this in vitro investigation, differently surfaced implants affected osteoblast morphology, adhesion, proliferation, and differentiation. Sandblasted surfaces promoted the most suitable osteoblast behavior. © 2012 John Wiley & Sons A/S.

Inconsistent formation and nonfunction of insulin-positive cells from pancreatic endoderm derived from human embryonic stem cells in athymic nude rats.

PubMed

Matveyenko, Aleksey V; Georgia, Senta; Bhushan, Anil; Butler, Peter C

2010-11-01

Embryonic stem cell therapy has been proposed as a therapeutic strategy to restore β-cell mass and function in T1DM. Recently, a group from Novocell (now ViaCyte) reported successful development of glucose-responsive islet-like structures after implantation of pancreatic endoderm (PE) derived from human embryonic stem cells (hESC) into immune-deficient mice. Our objective was to determine whether implantation of hESC-derived pancreatic endoderm from Novocell into athymic nude rats results in development of viable glucose-responsive pancreatic endocrine tissue. Athymic nude rats were implanted with PE derived from hESC either via implantation into the epididymal fat pads or by subcutaneous implantation into TheraCyte encapsulation devices for 20 wk. Blood glucose, weight, and human insulin/C-peptide secretion were monitored by weekly blood draws. Graft β-cell function was assessed by a glucose tolerance test, and graft morphology was assessed by immunohistochemistry and immunofluorescence. At 20 wk postimplantation, epididymal fat-implanted PE progressed to develop islet-like structures in 50% of implants, with a mean β-cell fractional area of 0.8 ± 0.3%. Human C-peptide and insulin were detectable, but at very low levels (C-peptide = 50 ± 26 pmol/l and insulin = 15 ± 7 pmol/l); however, there was no increase in human C-peptide/insulin levels after glucose challenge. There was no development of viable pancreatic tissue or meaningful secretory function when human PE was implanted in the TheraCyte encapsulation devices. These data confirm that islet-like structures develop from hESC differentiated to PE by the protocol developed by NovoCell. However, the extent of endocrine cell formation and secretory function is not yet sufficient to be clinically relevant.

Inconsistent formation and nonfunction of insulin-positive cells from pancreatic endoderm derived from human embryonic stem cells in athymic nude rats

PubMed Central

Matveyenko, Aleksey V.; Georgia, Senta; Bhushan, Anil

2010-01-01

Embryonic stem cell therapy has been proposed as a therapeutic strategy to restore β-cell mass and function in T1DM. Recently, a group from Novocell (now ViaCyte) reported successful development of glucose-responsive islet-like structures after implantation of pancreatic endoderm (PE) derived from human embryonic stem cells (hESC) into immune-deficient mice. Our objective was to determine whether implantation of hESC-derived pancreatic endoderm from Novocell into athymic nude rats results in development of viable glucose-responsive pancreatic endocrine tissue. Athymic nude rats were implanted with PE derived from hESC either via implantation into the epididymal fat pads or by subcutaneous implantation into TheraCyte encapsulation devices for 20 wk. Blood glucose, weight, and human insulin/C-peptide secretion were monitored by weekly blood draws. Graft β-cell function was assessed by a glucose tolerance test, and graft morphology was assessed by immunohistochemistry and immunofluorescence. At 20 wk postimplantation, epididymal fat-implanted PE progressed to develop islet-like structures in 50% of implants, with a mean β-cell fractional area of 0.8 ± 0.3%. Human C-peptide and insulin were detectable, but at very low levels (C-peptide = 50 ± 26 pmol/l and insulin = 15 ± 7 pmol/l); however, there was no increase in human C-peptide/insulin levels after glucose challenge. There was no development of viable pancreatic tissue or meaningful secretory function when human PE was implanted in the TheraCyte encapsulation devices. These data confirm that islet-like structures develop from hESC differentiated to PE by the protocol developed by NovoCell. However, the extent of endocrine cell formation and secretory function is not yet sufficient to be clinically relevant. PMID:20587750

Effect of pH on in vitro biocompatibility of orthodontic miniscrew implants.

PubMed

Galeotti, Angela; Uomo, Roberto; Spagnuolo, Gianrico; Paduano, Sergio; Cimino, Roberta; Valletta, Rosa; D'Antò, Vincenzo

2013-07-01

Although the clinical use of miniscrews has been investigated on a large scale, little is known about their biocompatibility. Since low pH can affect corrosion resistance, the aim of this study was to evaluate the cytotoxic effect of orthodontic miniscrews in different pH conditions. Four orthodontic miniscrews of stainless steel and grade IV and grade V titanium were immersed in a pH 7 and pH 4 saline solution for 1, 7, 14, 21, 28, and 84 days. Human osteogenic sarcoma cells (U2OS), permanent human keratinocytes (HaCat), and primary human gingival fibroblasts (HGF) were exposed to eluates, and the mitochondrial dehydrogenase activity was measured after 24 h to assess the cytoxicity. The results were analyzed using the Mann-Whitney U test (P<0.05). When exposed to pH 7-conditioned eluates, the cell lines showed an even greater viability than untreated cells. On the contrary, the results revealed a statistically significant decrease in U2OS, HaCat, and HGF viability after exposure to eluates obtained at pH 4. Among the cell lines tested, HGF showed the most significant decrease of mitochondrial activity. Interestingly, grade V titanium miniscrews caused highest toxic effects when immersed at pH 4. The results suggested that at pH 7, all the miniscrews are biocompatible while the eluates obtained at pH 4 showed significant cytotoxicity response. Moreover, different cell lines can produce different responses to miniscrew eluates.

Poly-ε-caprolactone Coated and Functionalized Porous Titanium and Magnesium Implants for Enhancing Angiogenesis in Critically Sized Bone Defects

PubMed Central

Roland, Laura; Grau, Michael; Matena, Julia; Teske, Michael; Gieseke, Matthias; Kampmann, Andreas; Beyerbach, Martin; Murua Escobar, Hugo; Haferkamp, Heinz; Gellrich, Nils-Claudius; Nolte, Ingo

2015-01-01

For healing of critically sized bone defects, biocompatible and angiogenesis supporting implants are favorable. Murine osteoblasts showed equal proliferation behavior on the polymers poly-ε-caprolactone (PCL) and poly-(3-hydroxybutyrate)/poly-(4-hydroxybutyrate) (P(3HB)/P(4HB)). As vitality was significantly better for PCL, it was chosen as a suitable coating material for further experiments. Titanium implants with 600 µm pore size were evaluated and found to be a good implant material for bone, as primary osteoblasts showed a vitality and proliferation onto the implants comparable to well bottom (WB). Pure porous titanium implants and PCL coated porous titanium implants were compared using Live Cell Imaging (LCI) with Green fluorescent protein (GFP)-osteoblasts. Cell count and cell covered area did not differ between the implants after seven days. To improve ingrowth of blood vessels into porous implants, proangiogenic factors like Vascular Endothelial Growth Factor (VEGF) and High Mobility Group Box 1 (HMGB1) were incorporated into PCL coated, porous titanium and magnesium implants. An angiogenesis assay was performed to establish an in vitro method for evaluating the impact of metallic implants on angiogenesis to reduce and refine animal experiments in future. Incorporated concentrations of proangiogenic factors were probably too low, as they did not lead to any effect. Magnesium implants did not yield evaluable results, as they led to pH increase and subsequent cell death. PMID:26703586

Poly-ε-caprolactone Coated and Functionalized Porous Titanium and Magnesium Implants for Enhancing Angiogenesis in Critically Sized Bone Defects.

PubMed

Roland, Laura; Grau, Michael; Matena, Julia; Teske, Michael; Gieseke, Matthias; Kampmann, Andreas; Beyerbach, Martin; Murua Escobar, Hugo; Haferkamp, Heinz; Gellrich, Nils-Claudius; Nolte, Ingo

2015-12-22

For healing of critically sized bone defects, biocompatible and angiogenesis supporting implants are favorable. Murine osteoblasts showed equal proliferation behavior on the polymers poly-ε-caprolactone (PCL) and poly-(3-hydroxybutyrate)/poly-(4-hydroxybutyrate) (P(3HB)/P(4HB)). As vitality was significantly better for PCL, it was chosen as a suitable coating material for further experiments. Titanium implants with 600 µm pore size were evaluated and found to be a good implant material for bone, as primary osteoblasts showed a vitality and proliferation onto the implants comparable to well bottom (WB). Pure porous titanium implants and PCL coated porous titanium implants were compared using Live Cell Imaging (LCI) with Green fluorescent protein (GFP)-osteoblasts. Cell count and cell covered area did not differ between the implants after seven days. To improve ingrowth of blood vessels into porous implants, proangiogenic factors like Vascular Endothelial Growth Factor (VEGF) and High Mobility Group Box 1 (HMGB1) were incorporated into PCL coated, porous titanium and magnesium implants. An angiogenesis assay was performed to establish an in vitro method for evaluating the impact of metallic implants on angiogenesis to reduce and refine animal experiments in future. Incorporated concentrations of proangiogenic factors were probably too low, as they did not lead to any effect. Magnesium implants did not yield evaluable results, as they led to pH increase and subsequent cell death.

Caspase-8 acts as a key upstream executor of mitochondria during justicidin A-induced apoptosis in human hepatoma cells.

PubMed

Su, Chun-Li; Huang, Lynn L H; Huang, Li-Min; Lee, Jenq-Chang; Lin, Chun-Nan; Won, Shen-Jeu

2006-05-29

Justicia procumbens is a traditional Taiwanese herbal remedy used to treat fever, pain, and cancer. Justicidin A, isolated from Justicia procumbens, has been reported to suppress in vitro growth of several tumor cell lines as well as hepatoma cells. In this study, justicidin A activated caspase-8 to increase tBid, disrupted mitochondrial membrane potential (Delta psi(m)), and caused the release of cytochrome c and Smac/DIABLO in Hep 3B and Hep G2 cells. Justicidin A also reduced Bcl-x(L) and increased Bax and Bak in mitochondria. Caspase-8 inhibitor (Z-IETD) attenuated the justicidin A-induced disruption of Delta psi(m). Growth of Hep 3B implanted in NOD-SCID mice was suppressed significantly by oral justicidin A (20 mg/kg/day). These results indicate that justicidin A-induced apoptosis in these cells proceeds via caspase-8 and is followed by mitochondrial disruption.

Transformation of Epithelial Ovarian Cancer Stemlike Cells into Mesenchymal Lineage via EMT Results in Cellular Heterogeneity and Supports Tumor Engraftment

PubMed Central

Jiang, Hua; Lin, Xiaolong; Liu, Yingtao; Gong, Wenjia; Ma, Xiaoling; Yu, Yinhua; Xie, Yi; Sun, Xiaoxi; Feng, Youji; Janzen, Viktor; Chen, Tong

2012-01-01

Ovarian cancers are heterogeneous and contain stemlike cells that are able to self-renew and are responsible for sustained tumor growth. Metastasis in the peritoneal cavity occurs more frequently in ovarian cancer than in other malignancies, but the underlying mechanism remains largely unknown. We have identified that ovarian cancer stemlike cells (CSCs), which were defined as side population (SP) cells, were present in patients’ ascitic fluid and mesenchymally transformed cell lines, ES-2 and HO-8910PM. SP cells, which were sorted from both cell lines and implanted into immunocompromised mice, were localized to the xenografted tumor boundary. In addition, SP cells exhibited an epithelial phenotype and showed a distinct gene expression profile with reduced expression of cell adhesion molecules (CAMs), indicating that SP cells exert an important role in ovarian cancer progression on the basis of their delicate interaction with the surrounding microenvironment and anatomical localization in tumors. In contrast, non-SP cells exhibited a more mesenchymal phenotype and showed more increased invasive potential than SP cells. This heterogeneity was observed as an endogenous transformation via the epithelial–mesenchymal transition (EMT) process. Inhibition of the EMT process by Snail1 silencing reduced the SP cell frequency, and affected their invasive capacity and engraftment. These findings illustrate the interplay between epithelial ovarian CSCs and the EMT, and exert a link to explain tumor heterogeneity and its necessity for ovarian cancer maintenance, metastasis and progression. PMID:22801793

Cell Adhesion and in Vivo Osseointegration of Sandblasted/Acid Etched/Anodized Dental Implants

PubMed Central

Kim, Mu-Hyon; Park, Kyeongsoon; Choi, Kyung-Hee; Kim, Soo-Hong; Kim, Se Eun; Jeong, Chang-Mo; Huh, Jung-Bo

2015-01-01

The authors describe a new type of titanium (Ti) implant as a Modi-anodized (ANO) Ti implant, the surface of which was treated by sandblasting, acid etching (SLA), and anodized techniques. The aim of the present study was to evaluate the adhesion of MG-63 cells to Modi-ANO surface treated Ti in vitro and to investigate its osseointegration characteristics in vivo. Four different types of Ti implants were examined, that is, machined Ti (control), SLA, anodized, and Modi-ANO Ti. In the cell adhesion study, Modi-ANO Ti showed higher initial MG-63 cell adhesion and induced greater filopodia growth than other groups. In vivo study in a beagle model revealed the bone-to-implant contact (BIC) of Modi-ANO Ti (74.20% ± 10.89%) was much greater than those of machined (33.58% ± 8.63%), SLA (58.47% ± 12.89), or ANO Ti (59.62% ± 18.30%). In conclusion, this study demonstrates that Modi-ANO Ti implants produced by sandblasting, acid etching, and anodizing improve cell adhesion and bone ongrowth as compared with machined, SLA, or ANO Ti implants. These findings suggest that the application of Modi-ANO surface treatment could improve the osseointegration of dental implant. PMID:25955650

Biohybrid cochlear implants in human neurosensory restoration.

PubMed

Roemer, Ariane; Köhl, Ulrike; Majdani, Omid; Klöß, Stephan; Falk, Christine; Haumann, Sabine; Lenarz, Thomas; Kral, Andrej; Warnecke, Athanasia

2016-10-07

The success of cochlear implantation may be further improved by minimizing implantation trauma. The physical trauma of implantation and subsequent immunological sequelae can affect residual hearing and the viability of the spiral ganglion. An ideal electrode should therefore decrease post-implantation trauma and provide support to the residual spiral ganglion population. Combining a flexible electrode with cells producing and releasing protective factors could present a potential means to achieve this. Mononuclear cells obtained from bone marrow (BM-MNC) consist of mesenchymal and hematopoietic progenitor cells. They possess the innate capacity to induce repair of traumatized tissue and to modulate immunological reactions. Human bone marrow was obtained from the patients that received treatment with biohybrid electrodes. Autologous mononuclear cells were isolated from bone marrow (BM-MNC) by centrifugation using the Regenlab™ THT-centrifugation tubes. Isolated BM-MNC were characterised using flow cytometry. In addition, the release of cytokines was analysed and their biological effect tested on spiral ganglion neurons isolated from neonatal rats. Fibrin adhesive (Tisseal™) was used for the coating of silicone-based cochlear implant electrode arrays for human use in order to generate biohybrid electrodes. Toxicity of the fibrin adhesive and influence on insertion, as well on the cell coating, was investigated. Furthermore, biohybrid electrodes were implanted in three patients. Human BM-MNC release cytokines, chemokines, and growth factors that exert anti-inflammatory and neuroprotective effects. Using fibrin adhesive as a carrier for BM-MNC, a simple and effective cell coating procedure for cochlear implant electrodes was developed that can be utilised on-site in the operating room for the generation of biohybrid electrodes for intracochlear cell-based drug delivery. A safety study demonstrated the feasibility of autologous progenitor cell transplantation in humans as an adjuvant to cochlear implantation for neurosensory restoration. This is the first report of the use of autologous cell transplantation to the human inner ear. Due to the simplicity of this procedure, we hope to initiate its widespread utilization in various fields.

Systematic implantation of dedifferentiated fat cells ameliorated monoclonal antibody 1-22-3-induced glomerulonephritis by immunosuppression with increases in TNF-stimulated gene 6.

PubMed

Maruyama, Takashi; Fukuda, Noboru; Matsumoto, Taro; Kano, Koichiro; Endo, Morito; Kazama, Minako; Kazama, Tomohiko; Ikeda, Jin; Matsuda, Hiroyuki; Ueno, Takahiro; Abe, Masanori; Okada, Kazuyoshi; Soma, Masayoshi; Matsumoto, Koichi; Kawachi, Hiroshi

2015-04-16

Implantation of mesenchymal stem cells (MSCs) has recently been reported to repair tissue injuries through anti-inflammatory and immunosuppressive effects. We established dedifferentiated fat (DFAT) cells that show identical characteristics to MSCs. We examined the effects of 10(6) of DFAT cells infused through renal artery or tail vein on monoclonal antibody (mAb) 1-22-3-induced glomerulonephritis (as an immunological type of renal injury) and adriamycin-induced nephropathy (as a non-immunological type of renal injury) in rats. The mAb 1-22-3-injected rats were also implanted with 10(6) of DFAT cells transfected with TSG-6 siRNA through tail vein. Although DFAT cells transfused into blood circulation through the tail vein were trapped mainly in lungs without reaching the kidneys, implantation of DFAT cells reduced proteinuria and improved glomerulosclerosis and interstitial fibrosis. Implantation of DFAT cells through the tail vein significantly decreased expression of kidney injury molecule-1, collagen IV and fibronectin mRNAs, whereas nephrin mRNA expression was increased. Implantation of DFAT cells did not improve adriamycin-induced nephropathy, but significantly decreased the glomerular influx of macrophages, common leukocytes and pan T cells. However, the glomerular influx of helper T cells, was increased. Implantation of DFAT cells decreased expression of interleukin (IL)-6 and IL-12β mRNAs and increased expression of TNF-stimulated gene (TSG)-6 mRNA in renal cortex from mAb 1-22-3-injected rats. The basal level of TSG-6 protein was significantly higher in DFAT cells than in fibroblasts. Expression of TSG-6 mRNA in MCs cocultured with DFAT cells was significantly higher than in mesangial cells or DFAT cells alone. Systematic implantation of DFAT cells with TSG-6 siRNA through tail vein did not improve proteinuria, renal dysfunction and renal degeneration in the mAb 1-22-3-injected rats. Systematic implantation of DFAT cells effectively ameliorated mAb 1-22-3-induced glomerulonephritis through immunosuppressive effects accompanied by the suppression of macrophage infiltration and expression of IL-6, IL-10 and IL-12β, and increased production of serum and renal TSG-6 that improved the mAb 1-22-3-induced renal degeneration by the immunosuppressive effects of TSG-6. Thus DFAT cells will be suitable cell source for the treatment of immunological progressive renal diseases.

Endothelial Cell Implantation and Survival within Experimental Gliomas

NASA Astrophysics Data System (ADS)

Lal, Bachchu; Indurti, Ravi R.; Couraud, Pierre-Olivier; Goldstein, Gary W.; Laterra, John

1994-10-01

The delivery of therapeutic genes to primary brain neoplasms opens new opportunities for treating these frequently fatal tumors. Efficient gene delivery to tissues remains an important obstacle to therapy, and this problem has unique characteristics in brain tumors due to the blood-brain and blood-tumor barriers. The presence of endothelial mitogens and vessel proliferation within solid tumors suggests that genetically modified endothelial cells might efficiently transplant to brain tumors. Rat brain endothelial cells immortalized with the adenovirus E1A gene and further modified to express the β-galactosidase reporter were examined for their ability to survive implantation to experimental rat gliomas. Rats received 9L, F98, or C6 glioma cells in combination with endothelial cells intracranially to caudate/putamen or subcutaneously to flank. Implanted endothelial cells were identified by β-galactosidase histochemistry or by polymerase chain reaction in all tumors up to 35 days postimplantation, the latest time examined. Implanted endothelial cells appeared to cooperate in tumor vessel formation and expressed the brain-specific endothelial glucose transporter type 1 as identified by immunohistochemistry. The proliferation of implanted endothelial cells was supported by their increased number within tumors between postimplantation days 14 and 21 (P = 0.015) and by their expression of the proliferation antigen Ki67. These findings establish that genetically modified endothelial cells can be stably engrafted to growing gliomas and suggest that endothelial cell implantation may provide a means of delivering therapeutic genes to brain neoplasms and other solid tumors. In addition, endothelial implantation to brain may be useful for defining mechanisms of brain-specific endothelial differentiation.

Hydroxyapatite grafted carbon nanotubes and graphene nanosheets: Promising bone implant materials

NASA Astrophysics Data System (ADS)

Oyefusi, Adebola; Olanipekun, Opeyemi; Neelgund, Gururaj M.; Peterson, Deforest; Stone, Julia M.; Williams, Ebonee; Carson, Laura; Regisford, Gloria; Oki, Aderemi

2014-11-01

In the present study, hydroxyapatite (HA) was successfully grafted to carboxylated carbon nanotubes (CNTs) and graphene nanosheets. The HA grafted CNTs and HA-graphene nanosheets were characterized using FT-IR, TGA, SEM and X-ray diffraction. The HA grafted CNTs and graphene nanosheets (CNTs-HA and Gr-HA) were further used to examine the proliferation and differentiation rate of temperature-sensitive human fetal osteoblastic cell line (hFOB 1.19). Total protein assays and western blot analysis of osteocalcin expression were used as indicators of cell proliferation and differentiation. Results indicated that hFOB 1.19 cells proliferate and differentiate well in treatment media containing CNTs-HA and graphene-HA. Both CNTs-HA and graphene-HA could be promising nanomaterials for use as scaffolds in bone tissue engineering.

Nanotextured titanium surfaces stimulate spreading, migration, and growth of rat mast cells.

PubMed

Marcatti Amarú Maximiano, William; Marino Mazucato, Vivian; Tambasco de Oliveira, Paulo; Célia Jamur, Maria; Oliver, Constance

2017-08-01

Titanium is a biomaterial widely used in dental and orthopedic implants. Since tissue-implant interactions occur at the nanoscale level, nanotextured titanium surfaces may affect cellular activity and modulate the tissue response that occurs at the tissue-implant interface. Therefore, the characterization of diverse cell types in response to titanium surfaces with nanotopography is important for the rational design of implants. Mast cells are multifunctional cells of the immune system that release a range of chemical mediators involved in the inflammatory response that occurs at the tissue-implant interface. Therefore, the aim of this study was to investigate the effects of the nanotopography of titanium surfaces on the physiology of mast cells. The results show that the nanotopography of titanium surfaces promoted the spreading of mast cells, which was accompanied by the reorganization of the cytoskeleton. Also, the nanotopography of titanium surfaces enhanced cell migration and cell growth, but did not alter the number of adherent cells in first hours of culture or affect focal adhesions and mediator release. Thus, the results show that nanotopography of titanium surfaces can affect mast cell physiology, and represents an improved strategy for the rational production of surfaces that stimulate tissue integration with the titanium implants. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 2150-2161, 2017. © 2017 Wiley Periodicals, Inc.

Effects of nerve cells and adhesion molecules on nerve conduit for peripheral nerve regeneration

PubMed Central

Fiorellini, Joseph P.

2017-01-01

Background For peripheral nerve regeneration, recent attentions have been paid to the nerve conduits made by tissue-engineering technique. Three major elements of tissue-engineering are cells, molecules, and scaffolds. Methods In this study, the attachments of nerve cells, including Schwann cells, on the nerve conduit and the effects of both growth factor and adhesion molecule on these attachments were investigated. Results The attachment of rapidly-proliferating cells, C6 cells and HS683 cells, on nerve conduit was better than that of slowly-proliferating cells, PC12 cells and Schwann cells, however, the treatment of nerve growth factor improved the attachment of slowly-proliferating cells. In addition, the attachment of Schwann cells on nerve conduit coated with fibronectin was as good as that of Schwann cells treated with glial cell line-derived neurotrophic factor (GDNF). Conclusions Growth factor changes nerve cell morphology and affects cell cycle time. And nerve growth factor or fibronectin treatment is indispensable for Schwann cell to be used for implantation in artificial nerve conduits. PMID:29090249

Enhanced cytocompatibility and reduced genotoxicity of polydimethylsiloxane modified by plasma immersion ion implantation.

PubMed

Tong, Liping; Zhou, Wenhua; Zhao, Yuetao; Yu, Xuefeng; Wang, Huaiyu; Chu, Paul K

2016-12-01

Polydimethylsiloxane(PDMS) is a common industrial polymer with advantages such as ease of fabrication, tunable hardness, and other desirable properties, but the basic (-OSi(CH 3 ) 2 -) n structure in PDMS is inherently hydrophobic thereby hampering application to biomedical engineering. In this study, plasma immersion ion implantation (PIII) is conducted on PDMS to improve the biological properties. PIII forms wrinkled "herringbone" patterns and abundant O-containing functional groups on PDMS to alter the surface hydrophilicity. The biocompatibility of the modified PDMS is assessed with Chinese hamster ovarian cells and compared to that of the untreated PDMS. Our results reveal that the PDMS samples after undergoing PIII have better cytocompatibility and lower genotoxicity. PIII which is a non-line-of-sight technique extends the application of PDMS to the biomedical field. Copyright © 2016 Elsevier B.V. All rights reserved.

Implantation of GL261 neurospheres into C57/BL6 mice: a more reliable syngeneic graft model for research on glioma-initiating cells.

PubMed

Yi, Liang; Zhou, Chun; Wang, Bing; Chen, Tunan; Xu, Minhui; Xu, Lunshan; Feng, Hua

2013-08-01

Recent studies have demonstrated that inflammatory cells and inflammatory mediators are indispensable components of the tumor-initiating cell (TIC) niche and regulate the malignant behavior of TICs. However, conventional animal models for glioma-initiating cell (GIC) studies are based on the implantation of GICs from human glioblastoma (GBM) into immunodeficient mice without the regulation of immune system. Whether animal models can mimic the cellular microenvironment of malignancy and evaluate the biological features of GICs accurately is unclear. Here, we detected the biological features of neurosphere-like tumor cells derived from the murine GBM cell line GL261 (GL261-NS) and from primary human GBM (PGBM-NS) in vitro, injected GL261-NS into syngeneic C57/BL6 mouse brain and injected PGBM-NS into NOD/SCID mouse brain, respectively. The tumorigenic characteristics of the two different orthotopic transplantation models were analyzed and the histological discrepancy between grafts and human primary GBM was compared. We found that GICs enriched in GL261-NS, GL261-NS and PGBM-NS exhibited increased GIC potential and enhanced chemoresistance in vitro. GL261-NS was significantly more aggressive compared to GL261 adhesive cells (GL261-AC) in vivo and the enhanced aggression was more significant in syngeneic mice compared to immunodeficient mice. The discrepancy of tumorigenicity between GL261-NS and GL261-AC in C57/BL6 mice was also larger compared to that between PGBM-NS and PGBM-AC in immunodeficient mice. Syngrafts derived from GL261-NS in C57/BL6 mice corresponded to the human GBM histologically better, compared with xenografts derived from PGBM-NS in NOD/SCID mice, which lack inflammatory cells and inflammatory mediators. We conclude that the inflammatory niche is involved in the tumorigenicity of GICs and implantation of GL261-NS into C57/BL6 mice is a more reliable syngeneic graft model for in vivo study on GICs relative to the immunodeficiency model.

Analgesia Induced by Isolated Bovine Chromaffin Cells Implanted in Rat Spinal Cord

NASA Astrophysics Data System (ADS)

Sagen, Jacqueline; Pappas, George D.; Pollard, Harvey B.

1986-10-01

Chromaffin cells synthesize and secrete several neuroactive substances, including catecholamines and opioid peptides, that, when injected into the spinal cord, induce analgesia. Moreover, the release of these substances from the cells can be stimulated by nicotine. Since chromaffin cells from one species have been shown to survive when transplanted to the central nervous system of another species, these cells are ideal candidates for transplantation to alter pain sensitivity. Bovine chromaffin cells were implanted into the subarachnoid space of the lumbar spinal region in adult rats. Pain sensitivity and response to nicotine stimulation was determined at various intervals following cell implantation. Low doses of nicotine were able to induce potent analgesia in implanted animals as early as one day following their introduction into the host spinal cord. This response could be elicited at least through the 4 months the animals were tested. The induction of analgesia by nicotine in implanted animals was dose related. This analgesia was blocked by the opiate antagonist naloxone and partially attenuated by the adrenergic antagonist phentolamine. These results suggest that the analgesia is due to the stimulated release of opioid peptides and catecholamines from the implanted bovine chromaffin cells and may provide a new therapeutic approach for the relief of pain.

[Experimental study on vascular bundle implantation combined with cellular transplantation in treating rabbit femoral head necrosis].

PubMed

Chen, Shuang-Tao; Zhang, Wei-Ping; Liu, Chang-An; Wang, Jun-Jiang; Song, Heng-Yi; Chai, Zhi-wen

2013-03-01

To discuss the feasibility of vascular bundle implantation combined with allogeneic bone marrow stromal cells (BMSCs) transplantation in treating rabbit femoral head osteonecrosis and bone defect, in order to explore a new method for the treatment of femoral head necrosis. Thirty-six New Zealand rabbits were randomly divided into three groups,with 12 rabbits in each group. Bilateral femoral heads of the rabbits were studied in the experiment. The models were made by liquid nitrogen frozen, and the femoral heads were drilled to cause bone defect. Group A was the control group,group B was stem cells transplantaion group of allograft marrow stromal,and group C was stem cells transplantation group of allograft marrow stromal combined with vascular bundle implantation. Three rabbits of each group were sacrificed respectively at 2, 4, 8, 12 weeks after operation. All specimens of the femoral heads were sliced for HE staining. Furthermore ,vascular density and the percentage of new bone trabecula of femoral head coronary section in defect area were measured and analyzed statistically. In group C,new bone trabecula and original micrangium formed at the 2nd week after operation; new bone trabecula was lamellar and interlaced with abundant micrangium at the 8th week;at the 12th week,the broadened,coarsened bone trabecula lined up regularly,and the mature bone trabecula and new marrow were visible. At the 2nd week after operation,there was no statistical significance in the percentage of new bone trabecula of femoral head coronary section in defect area between group B and C. While at 4, 8, 12 week after operation, vascular density and the percentage of new bone trabecula of femoral head coronary section in defect area of group C was higher than that of group B. Allogeneic bone marrow stromal cells cultured in vivo can form new bone trabecula, and can be applied to allotransplant. Vascular bundle implanted into the bone defect area of femoral head necrosis could improve blood supply, and promote the formation of bone trabecula.

Overexpression of KH-type splicing regulatory protein regulates proliferation, migration, and implantation ability of osteosarcoma.

PubMed

Pruksakorn, Dumnoensun; Teeyakasem, Pimpisa; Klangjorhor, Jeerawan; Chaiyawat, Parunya; Settakorn, Jongkolnee; Diskul-Na-Ayudthaya, Penchatr; Chokchaichamnankit, Daranee; Pothacharoen, Peraphan; Srisomsap, Chantragan

2016-09-01

Osteosarcoma is a common malignant bone tumor in children and adolescents. The current 5-year survival rate is ~60% and that seems to be reaching a plateau. In order to improve treatment outcomes of osteosarcoma, a better understanding of tumorigenesis and underlying molecular mechanisms is required for searching out possible new treatment targets. This study aimed to identify the potential proteins involving the pathogenesis of osteosarcoma using a proteomics approach. Proteins extracted from primary cell culture of osteosarcoma (n=7) and osteoblasts of cancellous bone (n=7) were studied. Using 2-DE based proteomics and LC-MS/MS analysis, we successfully determined seven differentially expressed protein spots. Four upregulated proteins and three downregulated proteins were observed in this study in which KH-type splicing regulatory protein (KSRP) was selected for further exploration. KSRP was significantly upregulated in osteosarcoma cells compared to osteoblasts using western blot assay. In addition, immunohistochemistry demonstrated that KSRP was also highly expressed in osteosarcoma tissue of independent cases from the experimental group. More importantly, KSRP silencing of osteosarcoma cell lines significantly decreased cell proliferation, migration ability, as well as implantation and growth ability in chick chorioallantoic membrane assay. Taken together, these findings demonstrate, that KSRP plays important roles in regulatory controls of osteosarcoma pathogenesis and serves as a potentially therapeutic target of osteosarcoma.

Optical cell stimulation for neuronal excitation (Conference Presentation)

NASA Astrophysics Data System (ADS)

Johannsmeier, Sonja; Heeger, Patrick; Terakawa, Mitsuhiro; Heisterkamp, Alexander; Ripken, Tammo; Heinemann, Dag

2017-02-01

Optical manipulation of cellular functions represents a growing field in biomedical sciences. The possibility to modulate specific targets with high spatial and temporal precision in a contactless manner allows a broad range of applications. Here, we present a study on stimulation of neuronal cells by optical means. As a long-term objective, we seek to improve the performance of current electric neurostimulation, especially in the context of cochlear implants. Firstly, we tested a gold nanoparticle mediated approach to modulate transmembrane conductivity by irradiation using a picosecond pulsed Nd:YAG laser at 532 nm for 40 ms in a neuroblastoma cell line (N2A) and primary murine neurons. The light absorption leads to a rapid temperature increase of the gold nanoparticles, which can induce an increased permeabilisation of the cellular membrane. Calcium transients were recorded as an indicator of neuronal activity. Although calcium signals were reliably detected upon laser irradiation, the temporal behavior did not resemble action potentials. The origin of these signals was investigated by an inhibitor study. These results indicate calcium induced calcium release (CICR) as the major source of the calcium transients. Consecutively, we tested alternative approaches for cell stimulation, such as glutamate release and optogenetics, and evaluated the potential of these methods for the application in a cochlear implant. Compared to the gold nanoparticle approach, both techniques induce less cellular stress and reliably produce action potentials.

The influence of direct laser metal sintering implants on the early stages of osseointegration in diabetic mini-pigs.

PubMed

Tan, Naiwen; Liu, Xiangwei; Cai, Yanhui; Zhang, Sijia; Jian, Bo; Zhou, Yuchao; Xu, Xiaoru; Ren, Shuai; Wei, Hongbo; Song, Yingliang

2017-01-01

High failure rates of oral implants have been reported in diabetic patients due to the disruption of osseointegration. The aim of this study was to investigate whether direct laser metal sintering (DLMS) could improve osseointegration in diabetic animal models. Surface characterizations were carried out on two types of implants. Cell morphology and the osteogenic-related gene expression of MG63 cells were observed under conditions of DLMS and microarc oxidation (MAO). A diabetes model in mini-pigs was established by intravenous injection of streptozotocin (150 mg/kg), and a total of 36 implants were inserted into the mandibular region. Micro-computed tomography (micro-CT) and histologic evaluations were performed 3 and 6 months after implantation. The Ra (the average of the absolute height of all points) of MAO surface was 2.3±0.3 µm while the DLMS surface showed the Ra of 27.4±1.1 µm. The cells on DLMS implants spread out more podia than those on MAO implants through cell morphology analysis. Osteogenic-related gene expression was also dramatically increased in the DLMS group. Obvious improvement was observed in the micro-CT and Van Gieson staining analyses of DLMS implants compared with MAO at 3 months, although this difference disappeared by 6 months. DLMS implants showed a higher bone-implant contact percentage (33.2%±11.2%) at 3 months compared with MAO group (18.9%±7.3%) while similar results were showed at 6 months between DLMS group (42.8%±10.1%) and MAO group (38.3%±10.8%). The three-dimensional environment of implant surfaces with highly porous and fully interconnected channel and pore architectures can improve cell spreading and accelerate the progress of osseointegration in diabetic mini-pigs.

The center for production of single-photon emitters at the electrostatic-deflector line of the Tandem accelerator of LABEC (Florence)

NASA Astrophysics Data System (ADS)

Lagomarsino, Stefano; Sciortino, Silvio; Gelli, Nicla; Flatae, Assegid M.; Gorelli, Federico; Santoro, Mario; Chiari, Massimo; Czelusniac, Caroline; Massi, Mirko; Taccetti, Francesco; Agio, Mario; Giuntini, Lorenzo

2018-05-01

The line for the pulsed beam of the 3 MeV Tandetron accelerator at LABEC (Florence) has been upgraded for ion implantation experiments aiming at the fabrication of single-photon emitters in a solid-state matrix. A system based on Al attenuators has been calibrated in order to extend the energy range of the implanted ions from MeV down to the tens of keV. A new motorized XY stage has been installed in the implantation chamber for achieving ultra-fine control on the position of each implanted ion, allowing to reach the scale imposed by lateral straggling. A set-up for the activation of the implanted ions has been developed, based on an annealing furnace operating under controlled high-vacuum conditions. The first experiments have been performed with silicon ions implanted in diamond and the luminescent signal of the silicon-vacancy (SiV) center, peaked at 738 nm, has been observed for a wide range of implantation fluences (108 ÷ 1015 cm-2) and implantation depths (from a few nm to 2.4 μm). Studies on the efficiency of the annealing process have been performed and the activation yield has been measured to range from 1% to 3%. The implantation and annealing facility has thus been tuned for the production of SiV centers in diamond, but is in principle suitable for other ion species and solid-state matrices.

Free radicals generated by tantalum implants antagonize the cytotoxic effect of doxorubicin.

PubMed

Chen, Muwan; Hein, San; Le, Dang Q S; Feng, Wenzhou; Foss, Morten; Kjems, Jørgen; Besenbacher, Flemming; Zou, Xuenong; Bünger, Cody

2013-05-01

Little is known about the interaction between antineoplastic drugs and implants in bone cancer patients. We investigated the interaction between commercially available porous tantalum (Ta) implants and the chemotherapeutic drug, Doxorubicin (DOX). DOX solutions were prepared in the presence of Ta implant. The changes in fluorescence intensity of the DOX chromophore were measured by spectrofluorometry and the efficacy of DOX was evaluated by viability of rabbit rectal tumor cells (VX2). After 5 min interaction of the DOX solution (5 μg/ml) with the Ta implant, the fluorescent intensity of the DOX solution was 85% degraded, and only 20% the drug efficacy to kill VX2 cells was retained. However, after adding a reducing agent, Dithiothreitol (DTT, 10 μg/ml), 80% of the original fluorescence and 50% of the drug efficacy were restored while UV irradiation enhanced drug degradation in the presence of Ta implant. The action of DTT and UV irradiation indicated that reactive oxygen species (ROS) were involved in the drug degradation mechanism. We detected that Ta implants in aqueous medium produced hydroxyl radicals. Cells showed higher intracellular ROS activity when culture medium was incubated with the Ta implant prior to cell culture. It is concluded that the porous Ta implant antagonizes the cytotoxicity of DOX via ROS generation of the porous Ta implant. Copyright © 2013 Elsevier B.V. All rights reserved.

Implant Surface Design Regulates Mesenchymal Stem Cell Differentiation and Maturation

PubMed Central

Boyan, B.D.; Cheng, A.; Olivares-Navarrete, R.; Schwartz, Z.

2016-01-01

Changes in dental implant materials, structural design, and surface properties can all affect biological response. While bulk properties are important for mechanical stability of the implant, surface design ultimately contributes to osseointegration. This article reviews the surface parameters of dental implant materials that contribute to improved cell response and osseointegration. In particular, we focus on how surface design affects mesenchymal cell response and differentiation into the osteoblast lineage. Surface roughness has been largely studied at the microscale, but recent studies have highlighted the importance of hierarchical micron/submicron/nanosurface roughness, as well as surface roughness in combination with surface wettability. Integrins are transmembrane receptors that recognize changes in the surface and mediate downstream signaling pathways. Specifically, the noncanonical Wnt5a pathway has been implicated in osteoblastic differentiation of cells on titanium implant surfaces. However, much remains to be elucidated. Only recently have studies been conducted on the differences in biological response to implants based on sex, age, and clinical factors; these all point toward differences that advocate for patient-specific implant design. Finally, challenges in implant surface characterization must be addressed to optimize and compare data across studies. An understanding of both the science and the biology of the materials is crucial for developing novel dental implant materials and surface modifications for improved osseointegration. PMID:26927483

Effects of Coating a Titanium Alloy with Fibronectin on the Expression of Osteoblast Gene Markers in the MC3T3 Osteoprogenitor Cell Line

PubMed Central

Rapuano, Bruce E.; Hackshaw, Kyle M.; Schniepp, Hannes C.; MacDonald, Daniel E.

2013-01-01

Purpose A number of environmental and patient-related factors contribute to implant failure. A significant fraction of these failures can be attributed to limited osseointegration resulting from poor bone healing responses. The overall goal of this study was to determine whether surface treatment of a titanium-aluminum-vanadium alloy (Ti-6Al-4V) implant material with a biomimetic protein coating could promote the differentiation of attached osteoblastic cells. The specific aims of the study were to investigate whether osteoprogenitor cells cultured on a rigorously cleaned implant specimen showed a normal pattern of differentiation and whether preadsorbed fibronectin accelerated or enhanced osteoblast differentiation. Materials and Methods Ti-6Al-4V disks were rigorously cleaned, passivated in nitric acid, and dry heat–sterilized; some of the disks were then coated with 1 nmol/L fibronectin. MC3T3 osteoprogenitor cells were then cultured on the pretreated disks for several weeks. Quantitative real-time polymerase chain reaction was performed to measure changes over time in the mRNA levels of osteoblast genes. Results Fibronectin increased the peak expression of all analyzed osteoblast gene markers. “Early” genes that normally mark the proliferative phase (0 to 10 days) of osteoblastic development showed peak expression within the first 10 days after cell attachment to the titanium alloy. In contrast, “late” genes that normally mark the differentiation (10 to 20 days) and mineralization (20 to 36 days) phases of osteoblastogenesis achieved peak expression only after approximately 3 to 4 weeks of culture. Conclusions Osteoprogenitors cultured on a rigorously cleaned Ti-6Al-4V alloy were found to demonstrate a normal pattern of osteoblast differentiation. Preadsorbed fibronectin was observed to stimulate osteoblast differentiation during the mineralization phase of osteoblastogenesis. PMID:23057020

Apical Cyst Theory: a Missing Link.

PubMed

Huang, George T-J

2010-10-05

The mechanism of the formation of apical cyst has been elusive. Several theories have long been proposed and discussed speculating how an apical cyst is developed and formed in the jaw bone resulting from endododontic infection. Two popular theories are the nutritional deficiency theory and the abscess theory. The nutritional deficiency theory assumes that the over proliferated epithelial cells will form a ball mass such that the cells in the center of the mass will be deprived of nutrition. The abscess theory postulates that when an abscess cavity is formed in connective tissue, epithelial cells proliferate and line the preexisting cavity because of their inherent tendency to cover exposed connective tissue surfaces. Based on the nature of epithelial cells and the epithelium, nutritional theory is a fairy tale, while abscess theory at best just indicates that abscess may be one of the factors that allows the stratified epithelium to form but not to explain a mechanism that makes the cyst to form. Apical cyst formation is the result of proliferation of resting epithelial cells, due to inflammation, to a sufficient number such that they are able to form a polarized and stratified epithelial lining against dead tissues or foreign materials. These stratified epithelial lining expands along the dead tissue or foreign materials and eventually wrap around them as a spherical sac, i.e. a cyst. The space in the sac is considered the external environment separating the internal (tissue) environment - the natural function of epithelium. This theory may be tested by introducing a biodegradable device able to slowly release epithelial cell mitogens in an in vivo environment implanted with epithelial cells next to a foreign object. This will allow the cells to continuously proliferate which may form a cystic sac wrapping around the foreign object.

Differentiation of human adipose-derived stem cells co-cultured with urothelium cell line toward a urothelium-like phenotype in a nude murine model.

PubMed

Zhang, Ming; Peng, Yubing; Zhou, Zhe; Zhou, Juan; Wang, Zhong; Lu, Mujun

2013-02-01

To investigated the urothelium differentiation potential of adipose-derived stem cells (ASCs) that were coimplanted with the immortalized human bladder urothelium cell line (SV-HUC-1) into the subcutaneous tissue of athymic mice. The ASCs were isolated from the human adipose tissue of patients undergoing liposuction procedures and were expanded in vitro. After labeling with CM-DiI, the ASCs were mixed with SV-HUC-1 and implanted into the subcutaneous tissue of athymic mice for 2 and 4 weeks. The urothelium-specific markers uroplakin-Ia and uroplakin-II were detected by immunofluorescence. The transformation rate of ASCs into the urothelium phenotype was evaluated at each measurement point. We found that 25.87% ± 1.38% of ASCs expressed the urothelium-specific marker uroplakin-Ia and 23.60% ± 2.57% of ASCs expressed uroplakin-II 2 weeks after coimplantation with SV-HUC-1 in vivo. After 4 weeks, 70.07% ± 3.84% of ASCs expressed uroplakin-Ia and 65.56% ± 2.94% expressed uroplakin-II. However, no obvious organizational multilayered urothelium structure, such as that of the native bladder mucosa, was found in the subcutaneous tissues of the athymic mice. The results of our study have demonstrated that ASCs could be differentiated toward the urothelium-like phenotype when they were coimplanted in direct contact with cells of a mature urothelium cell line, and the proportion of differentiated cells increased from 2 to 4 weeks. The differentiation potential of ASCs toward the urothelial cell type suggests that ASCs might have potential to be used in urinary tract repair with a tissue engineering approach in the future. Copyright © 2013 Elsevier Inc. All rights reserved.

Apical Cyst Theory: a Missing Link

PubMed Central

Huang, George T.-J.

2012-01-01

Introduction The mechanism of the formation of apical cyst has been elusive. Several theories have long been proposed and discussed speculating how an apical cyst is developed and formed in the jaw bone resulting from endododontic infection. Two popular theories are the nutritional deficiency theory and the abscess theory. The nutritional deficiency theory assumes that the over proliferated epithelial cells will form a ball mass such that the cells in the center of the mass will be deprived of nutrition. The abscess theory postulates that when an abscess cavity is formed in connective tissue, epithelial cells proliferate and line the preexisting cavity because of their inherent tendency to cover exposed connective tissue surfaces. Based on the nature of epithelial cells and the epithelium, nutritional theory is a fairy tale, while abscess theory at best just indicates that abscess may be one of the factors that allows the stratified epithelium to form but not to explain a mechanism that makes the cyst to form. The hypothesis Apical cyst formation is the result of proliferation of resting epithelial cells, due to inflammation, to a sufficient number such that they are able to form a polarized and stratified epithelial lining against dead tissues or foreign materials. These stratified epithelial lining expands along the dead tissue or foreign materials and eventually wrap around them as a spherical sac, i.e. a cyst. The space in the sac is considered the external environment separating the internal (tissue) environment – the natural function of epithelium. Evaluation of the hypothesis This theory may be tested by introducing a biodegradable device able to slowly release epithelial cell mitogens in an in vivo environment implanted with epithelial cells next to a foreign object. This will allow the cells to continuously proliferate which may form a cystic sac wrapping around the foreign object. PMID:25346864

Composition and function of macroencapsulated human embryonic stem cell-derived implants: comparison with clinical human islet cell grafts.

PubMed

Motté, Evi; Szepessy, Edit; Suenens, Krista; Stangé, Geert; Bomans, Myriam; Jacobs-Tulleneers-Thevissen, Daniel; Ling, Zhidong; Kroon, Evert; Pipeleers, Daniel

2014-11-01

β-Cells generated from large-scale sources can overcome current shortages in clinical islet cell grafts provided that they adequately respond to metabolic variations. Pancreatic (non)endocrine cells can develop from human embryonic stem (huES) cells following in vitro derivation to pancreatic endoderm (PE) that is subsequently implanted in immune-incompetent mice for further differentiation. Encapsulation of PE increases the proportion of endocrine cells in subcutaneous implants, with enrichment in β-cells when they are placed in TheraCyte-macrodevices and predominantly α-cells when they are alginate-microencapsulated. At posttransplant (PT) weeks 20-30, macroencapsulated huES implants presented higher glucose-responsive plasma C-peptide levels and a lower proinsulin-over-C-peptide ratio than human islet cell implants under the kidney capsule. Their ex vivo analysis showed the presence of single-hormone-positive α- and β-cells that exhibited rapid secretory responses to increasing and decreasing glucose concentrations, similar to isolated human islet cells. However, their insulin secretory amplitude was lower, which was attributed in part to a lower cellular hormone content; it was associated with a lower glucose-induced insulin biosynthesis, but not with lower glucagon-induced stimulation, which together is compatible with an immature functional state of the huES-derived β-cells at PT weeks 20-30. These data support the therapeutic potential of macroencapsulated huES implants but indicate the need for further functional analysis. Their comparison with clinical-grade human islet cell grafts sets references for future development and clinical translation. Copyright © 2014 the American Physiological Society.

Microfabrication and characterization of an array of dielectric elastomer actuators generating uniaxial strain to stretch individual cells

NASA Astrophysics Data System (ADS)

Akbari, S.; Shea, H. R.

2012-04-01

Cells regulate their behavior in response to mechanical strains. Cell cultures to study mechanotransuction are typically cm2 in area, far too large to monitor single cell response. We have developed an array of dielectric elastomer microactuators as a tool to study mechanotransduction of individual cells. The array consists of 72 100 µm × 200 µm electroactive polymer actuators which expand uniaxially when a voltage is applied. Single cells will be attached on each actuator to study their response to periodic mechanical strains. The device is fabricated by patterning compliant microelectrodes on both sides of a 30 µm thick polydimethylsiloxane membrane, which is bonded to a Pyrex chip with 200 µm wide trenches. Low-energy metal ion implantation is used to make stretchable electrodes and we demonstrate here the successful miniaturization of such ion-implanted electrodes. The top electrode covers the full membrane area, while the bottom electrodes are 100 µm wide parallel lines, perpendicular to the trenches. Applying a voltage between the top and bottom electrodes leads to uniaxial expansion of the membrane at the intersection of the bottom electrodes and the trenches. To characterize the in-plane strain, an array of 4 µm diameter aluminum dots is deposited on each actuator. The position of each dot is tracked, allowing displacement and strain profiles to be measured as a function of voltage. The uniaxial strain reaches 4.7% at 2.9 kV with a 0.2 s response time, sufficient to stimulate most cells with relevant biological strains and frequencies.

Orthotopic Implantation of Intact Tumor Tissue Leads to Metastasis of OCUM-2MD3 Human Gastric Cancer in Nude Mice Visualized in Real Time by Intravital Fluorescence Imaging.

PubMed

Murakami, Takashi; Zhang, Yong; Wang, Xiaoen; Hiroshima, Yukihiko; Kasashima, Hiroaki; Yashiro, Masakazu; Hirakawa, Kosei; Miwa, Atsushi; Kiyuna, Tasuku; Matsuyama, Ryusei; Tanaka, Kuniya; Bouvet, Michael; Endo, Itaru; Hoffman, Robert M

2016-05-01

Orthotopic (literally "correct place") implantation of cancer in nude mice has long been known to be superior to subcutaneous transplantation because the orthotopic tumor can metastasize. We reported previously on surgical orthotopic implantation (SOI) of gastric cancer tissue in nude mice resulting in the formation of metastases in 100% of the mice with extensive primary growth to the regional lymph nodes, liver, and lung. In contrast, when cell suspensions were used to inject gastric cancer cells orthotopically, metastases occurred in only 6.7% of the mice with local tumor formation, emphasizing the importance of orthotopically implanting intact tissue to allow full expression of metastatic potential. However, the different behavior of tumors implanted orthotopically by the two methods has not been visualized in real time. OCUM-2MD3 human gastric cancer cells labeled with the fluorescent protein Azami-Green were implanted orthotopically as cells or tissue in nude mice. Orthotopic implantation of cells resulted in local spread on the stomach. In contrast, SOI of tumor tissue of OCUM-2MD3 resulted in vessel spread of the Azami-Green-expressing cancer cells. Metastasis was also observed in the left lobe of the liver after SOI. These results demonstrate the physiological importance of intact cancer tissue for orthotopic implantation in order for tumors to properly grow and express their metastatic potential. Copyright© 2016 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.

The Hidden Side of Disodium Cromolyn: from Mast Cell Stabilizer to an Angiogenic Factor and Antitumor Agent.

PubMed

Cimpean, Anca Maria; Raica, Marius

2016-12-01

Scattered data suggested that disodium cromolyn, well known as a mast cell stabilizer shows some effects on tumor cells and tumor-associated newly formed vascular networks. Most of these studies used tumor cell lines assessed by in vitro studies. Nor disodium cromolyn effects on melanoma cell lines were studied yet, neither its influence on recruited tumor blood vessels or angiogenic growth factors expression. We designed here a study regarding disodium cromolyn effects on A375 melanoma tumor cells implanted on chick embryo chorioallantoic membrane (CAM) and on blood vessels recruited by the experimental melanoma in the absence of mast cells, knowing that within CAM, the existence of mast cells are not certified yet. We also assessed the role of disodium cromolyn on the expression of several angiogenic growth factors. Disodium cromoglycate differentially acts on tumor cells and blood vessels. Extensive necrotic areas of experimental melanoma together with an increased number of peritumor blood vessels were observed in treated specimens as compared with untreated tumors. Disodium cromolyn inhibited VEGF and PDGF-BB expression, and had no effects on EG VEGF expression between treated and non treated specimens in a mast cells free microenvironment. Our results sustain the direct antitumor effects of sodium cromolyn and suggest the involvement of several growth factors in the recruitment of tumor vessels by A375 melanoma tumor cells. The expression of growth factors is differentially influenced by sodium cromolyn treatment.

Attachment and spreadout study of 3T3 cells onto PP track etched films

NASA Astrophysics Data System (ADS)

Smolko, Eduardo; Mazzei, Ruben; Tadey, Daniel; Lombardo, Daniel

2001-12-01

Polymer surface modifications are obtained by the application of radiation treatments and other physico-chemical methods: fission fragment (ff) irradiation and etching. The biocompatibility of the surface is then observed by cell seeding and cell adhesion experiments. Approaches to improvement of the cell adhesion are obtained by different methods: for example, in PS, cell adhesion is improved after ion implantation; in PMMA, after bombarding the polymer, the surface is reconditioned with surfactants and proteins and in PVDF, cell adhesion is assayed on nuclear tracks membranes. In this work, we obtained important cell adhesion improvements in PP films by irradiation with swift heavy ions and subsequent etching of the nuclear tracks. We use BOPP (isotactic -25 μm thickness). Irrradiations were performed with a Cf-252 californium ff source. The source has a heavy ff and a light one, with 160-200 MeV energy divided among them corresponding to ff energies between 1 and 2 MeV/amu. A chemical etching procedure consisting of a solution of sulphuric acid and chromium three oxide at 85 °C was used. The 3T3 NIH fibroblast cell line was used for the cell adhesion experiment. Here we report for the first time, the results of a series of experiments by varying the ff fluence and the etching time showing that attachment and spreadout of cells are very much improved in this cell line according to the number of pores and the pore size.

Transplantation of conditionally immortal auditory neuroblasts to the auditory nerve.

PubMed

Sekiya, Tetsuji; Holley, Matthew C; Kojima, Ken; Matsumoto, Masahiro; Helyer, Richard; Ito, Juichi

2007-04-01

Cell transplantation is a realistic potential therapy for replacement of auditory sensory neurons and could benefit patients with cochlear implants or acoustic neuropathies. The procedure involves many experimental variables, including the nature and conditioning of donor cells, surgical technique and degree of degeneration in the host tissue. It is essential to control these variables in order to develop cell transplantation techniques effectively. We have characterized a conditionally immortal, mouse cell line suitable for transplantation to the auditory nerve. Structural and physiological markers defined the cells as early auditory neuroblasts that lacked neuronal, voltage-gated sodium or calcium currents and had an undifferentiated morphology. When transplanted into the auditory nerves of rats in vivo, the cells migrated peripherally and centrally and aggregated to form coherent, ectopic 'ganglia'. After 7 days they expressed beta 3-tubulin and adopted a similar morphology to native spiral ganglion neurons. They also developed bipolar projections aligned with the host nerves. There was no evidence for uncontrolled proliferation in vivo and cells survived for at least 63 days. If cells were transplanted with the appropriate surgical technique then the auditory brainstem responses were preserved. We have shown that immortal cell lines can potentially be used in the mammalian ear, that it is possible to differentiate significant numbers of cells within the auditory nerve tract and that surgery and cell injection can be achieved with no damage to the cochlea and with minimal degradation of the auditory brainstem response.

A Cell-Adhesive Plasma Polymerized Allylamine Coating Reduces the In Vivo Inflammatory Response Induced by Ti6Al4V Modified with Plasma Immersion Ion Implantation of Copper

PubMed Central

Walschus, Uwe; Hoene, Andreas; Patrzyk, Maciej; Lucke, Silke; Finke, Birgit; Polak, Martin; Lukowski, Gerold; Bader, Rainer; Zietz, Carmen; Podbielski, Andreas; Nebe, J. Barbara; Schlosser, Michael

2017-01-01

Copper (Cu) could be suitable to create anti-infective implants based on Titanium (Ti), for example by incorporating Cu into the implant surface using plasma immersion ion implantation (Cu-PIII). The cytotoxicity of Cu might be circumvented by an additional cell-adhesive plasma polymerized allylamine film (PPAAm). Thus, this study aimed to examine in vivo local inflammatory reactions for Ti6Al4V implants treated with Cu-PIII (Ti-Cu), alone or with an additional PPAAm film (Ti-Cu-PPAAm), compared to untreated implants (Ti). Successful Cu-PIII and PPAAm treatment was confirmed with X-ray Photoelectron Spectroscopy. Storage of Ti-Cu and Ti-Cu-PPAAm samples in double-distilled water for five days revealed a reduction of Cu release by PPAAm. Subsequently, Ti, Ti-Cu and Ti-Cu-PPAAm samples were simultaneously implanted into the neck musculature of 24 rats. After 7, 14 and 56 days, peri-implant tissue was retrieved from 8 rats/day for morphometric immunohistochemistry of different inflammatory cells. On day 56, Ti-Cu induced significantly stronger reactions compared to Ti (tissue macrophages, antigen-presenting cells, T lymphocytes) and to Ti-Cu-PPAAm (tissue macrophages, T lymphocytes, mast cells). The response for Ti-Cu-PPAAm was comparable with Ti. In conclusion, PPAAm reduced the inflammatory reactions caused by Cu-PIII. Combining both plasma processes could be useful to create antibacterial and tissue compatible Ti-based implants. PMID:28726761

Expression of adhesion and extracellular matrix genes in human blastocysts upon attachment in a 2D co-culture system.

PubMed

Aberkane, A; Essahib, W; Spits, C; De Paepe, C; Sermon, K; Adriaenssens, T; Mackens, S; Tournaye, H; Brosens, J J; Van de, Velde H

2018-05-26

What are the changes in human embryos, in terms of morphology and gene expression, upon attachment to endometrial epithelial cells? Apposition and adhesion of human blastocysts to endometrial epithelial cells are predominantly initiated at the embryonic pole and these steps are associated with changes in expression of adhesion and extracellular matrix (ECM) genes in the embryo. Both human and murine embryos have been co-cultured with Ishikawa cells, although embryonic gene expression associated with attachment has not yet been investigated in an in-vitro implantation model. Vitrified human blastocysts were warmed and co-cultured for up to 48 h with Ishikawa cells, a model cell line for receptive endometrial epithelium. Six-days post fertilisation (6dpf) human embryos were co-cultured with Ishikawa cells for 12 h, 24 h (7dpf) or 48 h (8dpf) and attachment rate and morphological development investigated. Expression of 84 adhesion and ECM genes was analysed by quantitative PCR. Immunofluorescence microscopy was used to assess the expression of three informative genes at the protein level. Data are reported on 115 human embryos. Mann-Whitney U was used for statistical analysis between two groups, with P < 0.05 considered significant. The majority of embryos attached to Ishikawa cells at the level of the polar trophectoderm; 41% of co-cultured embryos were loosely attached after 12 h and 86% firmly attached after 24 h. Outgrowth of hCG-positive embryonic cells at 8dpf indicated differentiation of trophectoderm into invasive syncytiotrophoblast. Gene expression analysis was performed on loosely attached and unattached embryos co-cultured with Ishikawa cells for 12 h. In contrast to unattached embryos, loosely attached embryos expressed THBS1, TNC, COL12A1, CTNND2, ITGA3, ITGAV, and LAMA3 and had significantly higher CD44 and TIMP1 transcript levels (P = 0.014 and P = 0.029, respectively). LAMA3, THBS1 and TNC expression was validated at the protein level in firmly attached 7dpf embryos. Thrombospondin 1 (THBS1) resided in the cytoplasm of embryonic cells whereas laminin subunit alpha 3 (LAMA3) and tenascin C (TNC) were expressed on the cell surface of trophectoderm cells. Incubation with a neutralizing TNC antibody did not affect the rate of embryo attachment or hCG secretion. None. This in-vitro study made use of an endometrial adenocarcinoma cell line to mimic receptive luminal epithelium. Also, the number of embryos was limited. Contamination of recovered embryos with Ishikawa cells was unlikely based on their differential gene expression profiles. Taken together, we provide a 'proof of concept' that initiation of the implantation process coincides with the induction of specific embryonic genes. Genome-wide expression profiling of a larger sample set may provide insights into the molecular embryonic pathways underlying successful or failed implantation. A.A. was supported by a grant from the "Instituut voor Innovatie door Wetenschap en Technologie" (IWT, 121716, Flanders, Belgium). This work was supported by the "Wetenschappelijk Fonds Willy Gepts" (WFWG G142 and G170, Universitair Ziekenhuis Brussel). The authors declare no conflict of interest.

Cellular Responses Evoked by Different Surface Characteristics of Intraosseous Titanium Implants

PubMed Central

Feller, Liviu; Jadwat, Yusuf; Khammissa, Razia A. G.; Meyerov, Robin; Lemmer, Johan

2015-01-01

The properties of biomaterials, including their surface microstructural topography and their surface chemistry or surface energy/wettability, affect cellular responses such as cell adhesion, proliferation, and migration. The nanotopography of moderately rough implant surfaces enhances the production of biological mediators in the peri-implant microenvironment with consequent recruitment of differentiating osteogenic cells to the implant surface and stimulates osteogenic maturation. Implant surfaces with moderately rough topography and with high surface energy promote osteogenesis, increase the ratio of bone-to-implant contact, and increase the bonding strength of the bone to the implant at the interface. Certain features of implant surface chemistry are also important in enhancing peri-implant bone wound healing. It is the purpose of this paper to review some of the more important features of titanium implant surfaces which have an impact on osseointegration. PMID:25767803

Serial corneal endothelial cell loss with lathe-cut and injection-molded posterior chamber intraocular lenses.

PubMed

Kraff, M C; Sanders, D R; Lieberman, H L

1983-01-01

We compared endothelial cell loss of patients implanted with lathe-cut posterior chamber lenses and those implanted with injection-molded lenses over a three-year postoperative period. Results were based on more than 2,500 measurements of corneal endothelial density. Although the technique of cataract extraction (anterior chamber phacoemulsification, posterior chamber phacoemulsification, or planned extracapsular extraction) significantly affected cell loss (P less than .01), the type of implant (lathe-cut or injection-molded) did not. Significant continuing endothelial cell loss did not occur during the first three postoperative years with injection-molded lenses. There was, however, a statistically significant 7% to 15% additional cell loss after surgery over the first two to three postoperative years with lathe-cut implants. There have been no cases of corneal endothelial decompensation developing after implantation of injection-molded or lathe-cut lenses. Because a standard field clinical specular microscope was used in this study, cell counting errors cannot be ruled out as a cause of these findings.

Survival and Functionality of hESC-Derived Retinal Pigment Epithelium Cells Cultured as a Monolayer on Polymer Substrates Transplanted in RCS Rats.

PubMed

Thomas, Biju B; Zhu, Danhong; Zhang, Li; Thomas, Padmaja B; Hu, Yuntao; Nazari, Hossein; Stefanini, Francisco; Falabella, Paulo; Clegg, Dennis O; Hinton, David R; Humayun, Mark S

2016-05-01

To determine the safety, survival, and functionality of human embryonic stem cell-derived RPE (hESC-RPE) cells seeded on a polymeric substrate (rCPCB-RPE1 implant) and implanted into the subretinal (SR) space of Royal College of Surgeons (RCS) rats. Monolayers of hESC-RPE cells cultured on parylene membrane were transplanted into the SR space of 4-week-old RCS rats. Group 1 (n = 46) received vitronectin-coated parylene membrane without cells (rMSPM+VN), group 2 (n = 59) received rCPCB-RPE1 implants, and group 3 (n = 13) served as the control group. Animals that are selected based on optical coherence tomography screening were subjected to visual function assays using optokinetic (OKN) testing and superior colliculus (SC) electrophysiology. At approximately 25 weeks of age (21 weeks after surgery), the eyes were examined histologically for cell survival, phagocytosis, and local toxicity. Eighty-seven percent of the rCPCB-RPE1-implanted animals showed hESC-RPE survivability. Significant numbers of outer nuclear layer cells were rescued in both group 1 (rMSPM+VN) and group 2 (rCPCB-RPE1) animals. A significantly higher ratio of rod photoreceptor cells to cone photoreceptor cells was found in the rCPCB-RPE1-implanted group. Animals with rCPCB-RPE1 implant showed hESC-RPE cells containing rhodopsin-positive particles in immunohistochemistry, suggesting phagocytic function. Superior colliculus mapping data demonstrated that a significantly higher number of SC sites responded to light stimulus at a lower luminance threshold level in the rCPCB-RPE1-implanted group. Optokinetic data suggested both implantation groups showed improved visual acuity. These results demonstrate the safety, survival, and functionality of the hESC-RPE monolayer transplantation in an RPE dysfunction rat model.

Do patients with a failed metal-on-metal hip implant with a pseudotumor present differences in their peripheral blood lymphocyte subpopulations?

PubMed

Catelas, Isabelle; Lehoux, Eric A; Hurda, Ian; Baskey, Stephen J; Gala, Luca; Foster, Ryan; Kim, Paul R; Beaulé, Paul E

2015-12-01

Early adverse tissue reactions around metal-on-metal (MoM) hip replacements, especially pseudotumors, are a major concern. Because the causes and pathomechanisms of these pseudotumors remain largely unknown, clinical monitoring of patients with MoM bearings is challenging. The purpose of this study was to compare the lymphocyte subpopulations in peripheral blood from patients with a failed MoM hip implant with and without a pseudotumor and patients with a well-functioning MoM hip implant without a pseudotumor. Potential differences in the systemic immune response are expected to reflect local differences in the periprosthetic tissues. Consenting patients who underwent a revision of a failed MoM hip implant at The Ottawa Hospital (TOH) from 2011 to 2014, or presented with a well-functioning MoM hip implant for a postoperative clinical followup at TOH from 2012 to 2013, were recruited for this study, unless they met any of the exclusion criteria (including diagnosed conditions that can affect peripheral blood lymphocyte subpopulations). Patients with a failed implant were divided into two groups: those with a pseudotumor (two hip resurfacings and five total hip arthroplasties [THAs]) and those without a pseudotumor (10 hip resurfacings and two THAs). Patients with a well-functioning MoM hip implant (nine resurfacings and three THAs) at 5 or more years postimplantation and who did not have a pseudotumor as demonstrated sonographically served as the control group. Peripheral blood subpopulations of T cells (specifically T helper [Th] and cytotoxic T [Tc]), B cells, natural killer (NK) cells, memory T and B cells as well as type 1 (expressing interferon-γ) and type 2 (expressing interleukin-4) Th and Tc cells were analyzed by flow cytometry after immunostaining. Serum concentrations of cobalt and chromium were measured by inductively coupled plasma-mass spectrometry. The mean percentages of total memory T cells and, specifically, memory Th and memory Tc cells were lower in patients with a failed MoM hip implant with a pseudotumor than in both patients with a failed implant without a pseudotumor and patients with a well-functioning implant without a pseudotumor (memory Th cells: 29% ± 5% [means ± SD] versus 55% ± 17%, d = 1.8, 95% confidence interval [CI] [1.2, 2.5] and versus 48% ± 14%, d = 1.6, 95% CI [1.0, 2.2], respectively; memory Tc cells: 18% ± 5% versus 45% ± 14%, d = 2.3, 95% CI [1.5, 3.1] and versus 41% ± 12%, d = 2.3, 95% CI [1.5, 3.1], respectively; p < 0.001 in all cases). The mean percentage of memory B cells was also lower in patients with a failed MoM hip implant with a pseudotumor than in patients with a well-functioning implant without a pseudotumor (12% ± 8% versus 29% ± 16%, d = 1.3, 95% CI [0.7, 1.8], p = 0.025). In addition, patients with a failed MoM hip implant with a pseudotumor had overall lower percentages of type 1 Th cells than both patients with a failed implant without a pseudotumor and patients with a well-functioning implant without a pseudotumor (5.5% [4.9%-5.8%] [median with interquartile range] versus 8.7% [6.5%-10.2%], d = 1.4, 95% CI [0.8, 2.0] and versus 9.6% [6.4%-11.1%], d = 1.6, 95% CI [1.0, 2.2], respectively; p ≤ 0.010 in both cases). Finally, serum cobalt concentrations in patients with a failed MoM hip implant with a pseudotumor were overall higher than those in patients with a well-functioning implant without a pseudotumor (5.8 µg/L [2.9-17.0 µg/L] versus 0.9 µg/L [0.6-1.3 µg/L], d = 2.2, 95% CI [1.4, 2.9], p < 0.001). Overall, results suggest the presence of a type IV hypersensitivity reaction, with a predominance of type 1 Th cells, in patients with a failed MoM hip implant with a pseudotumor. The lower percentages of memory T cells (specifically Th and Tc) as well as type 1 Th cells in peripheral blood of patients with a failed MoM hip implant with a pseudotumor could potentially become diagnostic biomarkers for the detection of pseudotumors. Although implant design (hip resurfacing or THA) did not seem to affect the results, as suggested by the scatter of the data with respect to this parameter, future studies with additional patients could include the analysis of implant design in addition to correlations with histological analyses of specific Th subsets in periprosthetic tissues.

Genotoxicity of corrosion eluates obtained from endosseous implants.

PubMed

Ribeiro, Daniel Araki; Matsumoto, Mariza Akemi; Padovan, Luís Eduardo Marques; Marques, Mariângela Esther Alencar; Salvadori, Daisy Maria Fávero

2007-03-01

Commercially pure titanium alloys are currently used as metallic biomaterials in implantology. Corrosion phenomena appear to play a decisive role in metallic implant long-term behavior. Thus, the goal of this study was to examine the genotoxic potential of corrosion eluates obtained from dental implants using Chinese ovary hamster cells in vitro by the single-cell gel (comet) assay. This technique detects deoxyribonucleic acid strand breaks in individual cells in alkaline conditions. The materials tested included 3 dental implants commercially available. Each of the tested materials was corroded in a solution consisting of equal amounts of acetic acid and sodium chloride (0.1 M) for 1, 3, 7, 14, and 21 days. The Chinese ovary hamster cultures were then exposed to all corrosion eluates obtained from endosseous dental implants for 30 minutes at 37 degrees C. None of the eluates was found to exhibit genotoxicity, regardless of the type of dental implant used. The results suggest that all dental implants tested in this study did not induce deoxyribonucleic acid breakage as depicted by the single-cell gel (comet) assay.

Tunnel oxide passivated contacts formed by ion implantation for applications in silicon solar cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Reichel, Christian, E-mail: christian.reichel@ise.fraunhofer.de; National Renewable Energy Laboratory; Feldmann, Frank

Passivated contacts (poly-Si/SiO{sub x}/c-Si) doped by shallow ion implantation are an appealing technology for high efficiency silicon solar cells, especially for interdigitated back contact (IBC) solar cells where a masked ion implantation facilitates their fabrication. This paper presents a study on tunnel oxide passivated contacts formed by low-energy ion implantation into amorphous silicon (a-Si) layers and examines the influence of the ion species (P, B, or BF{sub 2}), the ion implantation dose (5 × 10{sup 14 }cm{sup −2} to 1 × 10{sup 16 }cm{sup −2}), and the subsequent high-temperature anneal (800 °C or 900 °C) on the passivation quality and junction characteristics using double-sided contacted silicon solar cells.more » Excellent passivation quality is achieved for n-type passivated contacts by P implantations into either intrinsic (undoped) or in-situ B-doped a-Si layers with implied open-circuit voltages (iV{sub oc}) of 725 and 720 mV, respectively. For p-type passivated contacts, BF{sub 2} implantations into intrinsic a-Si yield well passivated contacts and allow for iV{sub oc} of 690 mV, whereas implanted B gives poor passivation with iV{sub oc} of only 640 mV. While solar cells featuring in-situ B-doped selective hole contacts and selective electron contacts with P implanted into intrinsic a-Si layers achieved V{sub oc} of 690 mV and fill factor (FF) of 79.1%, selective hole contacts realized by BF{sub 2} implantation into intrinsic a-Si suffer from drastically reduced FF which is caused by a non-Ohmic Schottky contact. Finally, implanting P into in-situ B-doped a-Si layers for the purpose of overcompensation (counterdoping) allowed for solar cells with V{sub oc} of 680 mV and FF of 80.4%, providing a simplified and promising fabrication process for IBC solar cells featuring passivated contacts.« less

Loss of Canonical Smad4 Signaling Promotes KRAS Driven Malignant Transformation of Human Pancreatic Duct Epithelial Cells and Metastasis

PubMed Central

Leung, Lisa; Radulovich, Nikolina; Zhu, Chang-Qi; Wang, Dennis; To, Christine; Ibrahimov, Emin; Tsao, Ming-Sound

2013-01-01

Pancreatic ductal adenocarcinoma (PDAC) is the fourth most common cause of cancer death in North America. Activating KRAS mutations and Smad4 loss occur in approximately 90% and 55% of PDAC, respectively. While their roles in the early stages of PDAC development have been confirmed in genetically modified mouse models, their roles in the multistep malignant transformation of human pancreatic duct cells have not been directly demonstrated. Here, we report that Smad4 represents a barrier in KRAS-mediated malignant transformation of the near normal immortalized human pancreatic duct epithelial (HPDE) cell line model. Marked Smad4 downregulation by shRNA in KRAS G12V expressing HPDE cells failed to cause tumorigenic transformation. However, KRAS-mediated malignant transformation occurred in a new HPDE-TGF-β resistant (TβR) cell line that completely lacks Smad4 protein expression and is resistant to the mito-inhibitory activity of TGF-β. This transformation resulted in tumor formation and development of metastatic phenotype when the cells were implanted orthotopically into the mouse pancreas. Smad4 restoration re-established TGF-β sensitivity, markedly increased tumor latency by promoting apoptosis, and decreased metastatic potential. These results directly establish the critical combination of the KRAS oncogene and complete Smad4 inactivation in the multi-stage malignant transformation and metastatic progression of normal human HPDE cells. PMID:24386371

Modulation of the Substitution Pattern of 5-Aryl-2-Aminoimidazoles Allows Fine-Tuning of Their Antibiofilm Activity Spectrum and Toxicity

PubMed Central

Peeters, Elien; Hooyberghs, Geert; Robijns, Stijn; Waldrant, Kai; De Weerdt, Ami; Delattin, Nicolas; Liebens, Veerle; Kucharíková, Soňa; Tournu, Hélène; Verstraeten, Natalie; Dovgan, Barbara; Girandon, Lenart; Fröhlich, Mirjam; De Brucker, Katrijn; Michiels, Jan; Cammue, Bruno P. A.; Thevissen, Karin; Vanderleyden, Jozef; Van der Eycken, Erik

2016-01-01

We previously synthesized several series of compounds, based on the 5-aryl-2-aminoimidazole scaffold, that showed activity preventing the formation of Salmonella enterica serovar Typhimurium and Pseudomonas aeruginosa biofilms. Here, we further studied the activity spectrum of a number of the most active N1- and 2N-substituted 5-aryl-2-aminoimidazoles against a broad panel of biofilms formed by monospecies and mixed species of bacteria and fungi. An N1-substituted compound showed very strong activity against the biofilms formed by Gram-negative and Gram-positive bacteria and the fungus Candida albicans but was previously shown to be toxic against various eukaryotic cell lines. In contrast, 2N-substituted compounds were nontoxic and active against biofilms formed by Gram-negative bacteria and C. albicans but had reduced activity against biofilms formed by Gram-positive bacteria. In an attempt to develop nontoxic compounds with potent activity against biofilms formed by Gram-positive bacteria for application in antibiofilm coatings for medical implants, we synthesized novel compounds with substituents at both the N1 and 2N positions and tested these compounds for antibiofilm activity and toxicity. Interestingly, most of these N1-,2N-disubstituted 5-aryl-2-aminoimidazoles showed very strong activity against biofilms formed by Gram-positive bacteria and C. albicans in various setups with biofilms formed by monospecies and mixed species but lost activity against biofilms formed by Gram-negative bacteria. In light of application of these compounds as anti-infective coatings on orthopedic implants, toxicity against two bone cell lines and the functionality of these cells were tested. The N1-,2N-disubstituted 5-aryl-2-aminoimidazoles in general did not affect the viability of bone cells and even induced calcium deposition. This indicates that modulating the substitution pattern on positions N1 and 2N of the 5-aryl-2-aminoimidazole scaffold allows fine-tuning of both the antibiofilm activity spectrum and toxicity. PMID:27550355

Ectopic bone formation in nude rats using human osteoblasts seeded poly(3)hydroxybutyrate embroidery and hydroxyapatite-collagen tapes constructs.

PubMed

Mai, Ronald; Hagedorn, Manolo Gunnar; Gelinsky, Michael; Werner, Carsten; Turhani, Dritan; Späth, Heike; Gedrange, Tomas; Lauer, Günter

2006-09-01

The aim of this study was to evaluate the ectopic bone formation using tissue engineered cell-seeded constructs with two different scaffolds and primary human maxillary osteoblasts in nude rats over an implantation period of up to 96 days. Collagen I-coated Poly(3)hydroxybutyrate (PHB) embroidery and hydroxyapatite (HAP) collagen tapes were seeded with primary human maxillary osteoblasts (hOB) and implanted into athymic rnu/run rats. A total of 72 implants were placed into the back muscles of 18 rats. 24, 48 and 96 days after implantation, histological and histomorphometric analyses were made. The osteoblastic character of the cells was confirmed by immunocytochemistry and RT-PCR for osteocalcin. Histological analysis demonstrated that all cell-seeded constructs induced ectopic bone formation after 24, 48 and 96 days of implantation. There was more mineralized tissue in PHB constructs than in HAP-collagen tapes (at day 24; p < 0.05). Bone formation decreased with the increasing length of the implantation period. Osteocalcin expression verified the osteoblastic character of the cell-seeded constructs after implantation time. No bone formation and no osteocalcin expression were found in the control groups. Cell-seeded constructs either with PHB embroidery or HAP-collagen tapes can induce ectopic bone formation. However, the amount of bone formed decreased with increasing length of implantation.

Surface modification of implants in long bone.

PubMed

Förster, Yvonne; Rentsch, Claudia; Schneiders, Wolfgang; Bernhardt, Ricardo; Simon, Jan C; Worch, Hartmut; Rammelt, Stefan

2012-01-01

Coatings of orthopedic implants are investigated to improve the osteoinductive and osteoconductive properties of the implant surfaces and thus to enhance periimplant bone formation. By applying coatings that mimic the extracellular matrix a favorable environment for osteoblasts, osteoclasts and their progenitor cells is provided to promote early and strong fixation of implants. It is known that the early bone ongrowth increases primary implant fixation and reduces the risk of implant failure. This review presents an overview of coating titanium and hydroxyapatite implants with components of the extracellular matrix like collagen type I, chondroitin sulfate and RGD peptide in different small and large animal models. The influence of these components on cells, the inflammation process, new bone formation and bone/implant contact is summarized.

Surface modification of implants in long bone

PubMed Central

Förster, Yvonne; Rentsch, Claudia; Schneiders, Wolfgang; Bernhardt, Ricardo; Simon, Jan C.; Worch, Hartmut; Rammelt, Stefan

2012-01-01

Coatings of orthopedic implants are investigated to improve the osteoinductive and osteoconductive properties of the implant surfaces and thus to enhance periimplant bone formation. By applying coatings that mimic the extracellular matrix a favorable environment for osteoblasts, osteoclasts and their progenitor cells is provided to promote early and strong fixation of implants. It is known that the early bone ongrowth increases primary implant fixation and reduces the risk of implant failure. This review presents an overview of coating titanium and hydroxyapatite implants with components of the extracellular matrix like collagen type I, chondroitin sulfate and RGD peptide in different small and large animal models. The influence of these components on cells, the inflammation process, new bone formation and bone/implant contact is summarized. PMID:23507866

Foreign body giant cells selectively covering haptics of intraocular lens implants: indicators of poor toleration?

PubMed

Wolter, J R

1983-10-01

A Sputnik lens implant removed after five years because of bullous keratopathy exhibits a dense covering of its Supramid anterior staves with large foreign body giant cells, while its Prolene loops and Polymethylmethacrylate optics have attracted only few of these cell units. The glass-membrane-like component of the reactive membrane also shows significant differences on the different parts of this implant. The use of observation of the components of reactive membranes on lens implants as indicators of toleration in the eye is suggested.

Establishment and evaluation of a stable steroidogenic caprine luteal cell line.

PubMed

Li, Wei; Xu, Xingang; Huang, Yong; Li, Zhaocai; Yu, Gaoshui; Wang, Zhisheng; Ding, Li; Tong, Dewen

2012-07-15

Many physiological, biological, pharmacologic, and toxicologic events and compounds affect the function of Saanen dairy goat luteal cells, resulting in implantation failure or early embryonic loss. Although primary luteal cell cultures have been used, their finite lifespan precludes assessment of long-term effects. In the present study, primary caprine luteal cells (CLCs) were immortalized through transfection of a plasmid containing the human telomerase reverse transcriptase (hTERT) gene. The expression of hTERT and telomerase activity were evaluated in transduced CLCs (hTERT-CLCs). In this study, these cells steadily expressed hTERT gene and exhibited higher telomerase activity at Passages 30 and 50. The hTERT-CLCs at Passages 30 and 50 expressed genes encoding key proteins, enzymes and receptors inherent to normal luteal cells, e.g., steroidogenic acute regulatory protein (StAR), cytochrome P450 cholesterol side-chain cleavage enzyme (P450scc), 3β-hydroxysteroid dehydrogenase (3β-HSD), and LH-receptor (LH-R). In addition, immortalized caprine luteal cells produced detectable quantities of progesterone in response to 8-bromo-cAMP (8-Br-cAMP) or 22(R)-hydroxycholesterol (22R-HC) stimulation. Furthermore, this cell line appeared to proliferate more quickly than control cells, although no neoplastic transformation occurred either in vivo or in vitro. We concluded the immortalized CLCs by hTERT retained their original characteristics and may provide a useful model to study luteal cell functions. Copyright © 2012 Elsevier Inc. All rights reserved.

Cell-laden hydrogel/titanium microhybrids: Site-specific cell delivery to metallic implants for improved integration.

PubMed

Koenig, Geraldine; Ozcelik, Hayriye; Haesler, Lisa; Cihova, Martina; Ciftci, Sait; Dupret-Bories, Agnes; Debry, Christian; Stelzle, Martin; Lavalle, Philippe; Vrana, Nihal Engin

2016-03-01

Porous titanium implants are widely used in dental, orthopaedic and otorhinolaryngology fields to improve implant integration to host tissue. A possible step further to improve the integration with the host is the incorporation of autologous cells in porous titanium structures via cell-laden hydrogels. Fast gelling hydrogels have advantageous properties for in situ applications such as localisation of specific cells and growth factors at a target area without dispersion. The ability to control the cell types in different regions of an implant is important in applications where the target tissue (i) has structural heterogeneity (multiple cell types with a defined spatial configuration with respect to each other); (ii) has physical property gradients essential for its function (such as in the case of osteochondral tissue transition). Due to their near immediate gelation, such gels can also be used for site-specific modification of porous titanium structures, particularly for implants which would face different tissues at different locations. Herein, we describe a step by step design of a model system: the model cell-laden gel-containing porous titanium implants in the form of titanium microbead/hydrogel (maleimide-dextran or maleimide-PVA based) microhybrids. These systems enable the determination of the effect of titanium presence on gel properties and encapsulated cell behaviour as a miniaturized version of full-scale implants, providing a system compatible with conventional analysis methods. We used a fibroblast/vascular endothelial cell co-cultures as our model system and by utilising single microbeads we have quantified the effect of gel microenvironment (degradability, presence of RGD peptides within gel formulation) on cell behaviour and the effect of the titanium presence on cell behaviour and gel formation. Titanium presence slightly changed gel properties without hindering gel formation or affecting cell viability. Cells showed a preference to move towards the titanium beads and fibroblast proliferation was significantly higher in hybrids compared to gel only controls. The MMP (Matrix Metalloproteinase)-sensitive hydrogels induced sprouting by cells in co-culture configuration which was quantified by fluorescence microscopy, confocal microscopy and qRT-PCR (Quantitative Reverse transcription polymerase chain reaction). When the microhybrid up-scaled to 3D thick structures, cellular localisation in specific areas of the 3D titanium structures was achieved, without decreasing overall cell proliferation compared to titanium only scaffolds. Microhybrids of titanium and hydrogels are useful models for deciding the necessary modifications of metallic implants and they can be used as a modelling system for the study of tissue/titanium implant interactions. This article demonstrates a method to apply cell-laden hydrogels to porous titanium implants and a model of titanium/hydrogel interaction at micro-level using titanium microbeads. The feasibility of site-specific modification of titanium implants with cell-laden microgels has been demonstrated. Use of titanium microbeads in combination with hydrogels with conventional analysis techniques as described in the article can facilitate the characterisation of surface modification of titanium in a relevant model system. Copyright © 2016 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Establishing contact between cell-laden hydrogels and metallic implants with a biomimetic adhesive for cell therapy supported implants.

PubMed

Barthes, Julien; Mutschler, Angela; Dollinger, Camille; Gaudinat, Guillaume; Lavalle, Philippe; Le Houerou, Vincent; Brian McGuinness, Garrett; Engin Vrana, Nihal

2017-12-15

For in-dwelling implants, controlling the biological interface is a crucial parameter to promote tissue integration and prevent implant failure. For this purpose, one possibility is to facilitate the establishment of the interface with cell-laden hydrogels fixed to the implant. However, for proper functioning, the stability of the hydrogel on the implant should be ensured. Modification of implant surfaces with an adhesive represents a promising strategy to promote the adhesion of a cell-laden hydrogel on an implant. Herein, we developed a peptidic adhesive based on mussel foot protein (L-DOPA-L-lysine) 2 -L-DOPA that can be applied directly on the surface of an implant. At physiological pH, unoxidized (L-DOPA-L-lysine) 2 -L-DOPA was supposed to strongly adhere to metallic surfaces but it only formed a very thin coating (less than 1 nm). Once oxidized at physiological pH, (L-DOPA-L-lysine) 2 -L-DOPA forms an adhesive coating about 20 nm thick. In oxidized conditions, L-lysine can adhere to metallic substrates via electrostatic interaction. Oxidized L-DOPA allows the formation of a coating through self-polymerization and can react with amines so that this adhesive can be used to fix extra-cellular matrix based materials on implant surfaces through the reaction of quinones with amino groups. Hence, a stable interface between a soft gelatin hydrogel and metallic surfaces was achieved and the strength of adhesion was investigated. We have shown that the adhesive is non-cytotoxic to encapsulated cells and enabled the adhesion of gelatin soft hydrogels for 21 days on metallic substrates in liquid conditions. The adhesion properties of this anchoring peptide was quantified by a 180° peeling test with a more than 60% increase in peel strength in the presence of the adhesive. We demonstrated that by using a biomimetic adhesive, for the application of cell-laden hydrogels to metallic implant surfaces, the hydrogel/implant interface can be ensured without relying on the properties of the deposited biomaterials.

[Principles of energy sources of totally implantable hearing aids for inner ear hearing loss].

PubMed

Baumann, J W; Leysieffer, H

1998-02-01

A fully implantable hearing aid consists of a sound receptor (microphone), an electronic amplifier including active audio-signal processing, an electromechanical transducer (actuator) for stimulating the ear by vibration, and an energy source. The energy source may be either a primary cell or a rechargeable (secondary) cell. As the energy requirements of an implantable hearing aid are dependent on the operating principle of the actuator, the operating principles of electromagnetic and piezoelectric transducers were examined with respect to their relative power consumption. The analysis showed that the energy requirements of an implantable hearing aid are significantly increased when an electromagnetic transducer is used. The power consumption of a piezoelectric transducer was found to be less than that of the electronic components alone. The energy needed to run a fully implantable hearing aid under these conditions would be 38 mWH per day. Primary cells cannot provide the energy needed for a minimum operation time of 5 years (70 WH), and therefore rechargeable cells must be used. A theoretical appraisal was carried out on nickel-cadmium, nickel-metal hydride, and lithium-ion cells to determine their suitability as well as to assess the risks associated with their use in an implant. Safety measures were drawn up from the results. Ni-MH cells were found to be the most suitable for use as an energy source for implantable hearing-aids because they are more robust than Li ion cells and their storage capacity is double that of Ni-Cd cells of similar size.

Evaluation of the ion implantation process for production of solar cells from silicon sheet materials

NASA Technical Reports Server (NTRS)

Spitzer, M. B.

1983-01-01

For the ion implantation tooling was fabricated with which to hold dendritic web samples. This tooling permits the expeditious boron implantation of the back to form the back surface field (BSF). Baseline BSF web cells were fabricated.

Perlecan and syndecan-4 in uterine tissues during the early pregnancy in mice.

PubMed

San Martin, S; Soto-Suazo, M; Zorn, T M T

2004-07-01

During early pregnancy in mice, there is recruitment of specific immune cells, remodeling of the endometrium, cell differentiation and synthesis of new molecules. Immunohistochemistry was used to determine the distribution of perlecan and syndecan-4 in the uteri before and after embryo implantation. During pre-implantation, perlecan was identified in basement membranes and extracellular spaces of the endometrial stroma. In contrast, expression of syndecan-4 was quite weak. In the peri-implantation period, perlecan remained in the basement membranes, and it was no longer observed in the stroma and it was identified in the embryonic cells. On day 4 of pregnancy, syndecan-4 increased in the fibroblasts of the subepithelial stroma. After implantation, syndecan-4 was pronounced in pre-decidual and mature decidual cells. The coordinate balance between the pre- and post-implantation periods suggests a role of these two molecules in the adaptive modification of the uterine microenvironment to receive and implant the embryo.

Hybrid micro/nano-topography of a TiO2 nanotube-coated commercial zirconia femoral knee implant promotes bone cell adhesion in vitro.

PubMed

Frandsen, Christine J; Noh, Kunbae; Brammer, Karla S; Johnston, Gary; Jin, Sungho

2013-07-01

Various approaches have been studied to engineer the implant surface to enhance bone in-growth properties, particularly using micro- and nano-topography. In this study, the behavior of osteoblast (bone) cells was analyzed in response to a titanium oxide (TiO2) nanotube-coated commercial zirconia femoral knee implant consisting of a combined surface structure of a micro-roughened surface with the nanotube coating. The osteoblast cells demonstrated high degrees of adhesion and integration into the surface of the nanotube-coated implant material, indicating preferential cell behavior on this surface when compared to the bare implant. The results of this brief study provide sufficient evidence to encourage future studies. The development of such hierarchical micro- and nano-topographical features, as demonstrated in this work, can provide insightful designs for advanced bone-inducing material coatings on ceramic orthopedic implant surfaces. Copyright © 2013 Elsevier B.V. All rights reserved.

Evaluation of the ion implantation process for production of solar cells from silicon sheet materials

NASA Technical Reports Server (NTRS)

Spitzer, M. B.

1983-01-01

The objective of this program is the investigation and evaluation of the capabilities of the ion implantation process for the production of photovoltaic cells from a variety of present-day, state-of-the-art, low-cost silicon sheet materials. Task 1 of the program concerns application of ion implantation and furnace annealing to fabrication of cells made from dendritic web silicon. Task 2 comprises the application of ion implantation and pulsed electron beam annealing (PEBA) to cells made from SEMIX, SILSO, heat-exchanger-method (HEM), edge-defined film-fed growth (EFG) and Czochralski (CZ) silicon. The goals of Task 1 comprise an investigation of implantation and anneal processes applied to dendritic web. A further goal is the evaluation of surface passivation and back surface reflector formation. In this way, processes yielding the very highest efficiency can be evaluated. Task 2 seeks to evaluate the use of PEBA for various sheet materials. A comparison of PEBA to thermal annealing will be made for a variety of ion implantation processes.

Tumour response endpoints in the BA1112 rat sarcoma.

PubMed Central

Martin, D. F.; Moulder, J. E.; Fischer, J. J.

1980-01-01

The rat rhabdomyosarcoma BA1112 has a number of features which make it a useful model for the study of tumour response to radiation therapy. It is a transplantable tumour, isologous to an inbred line of WAG/Rij rats and it elicits no demonstrable host immune response. The tumour grows locally at the implantation site and rarely metastasizes. It is known to contain hypoxic cells which reoxygenate during a prolonged course of fractionated radiation therapy. The growth and radiation response characteristics of the tumour have remained stable for over 15 years. A newly developed in vitro assay for tumour cell clonogenicity greatly facilitates the measurement of radiation dose-response curves and the monitoring of cell response following in vivo treatment. The in vivo response of the tumour to fractionated radiation therapy is analysed in terms of cellular response, reoxygenation and cell proliferation. PMID:6932936

Silver nanoparticle-enriched diamond-like carbon implant modification as a mammalian cell compatible surface with antimicrobial properties

PubMed Central

Gorzelanny, Christian; Kmeth, Ralf; Obermeier, Andreas; Bauer, Alexander T.; Halter, Natalia; Kümpel, Katharina; Schneider, Matthias F.; Wixforth, Achim; Gollwitzer, Hans; Burgkart, Rainer; Stritzker, Bernd; Schneider, Stefan W.

2016-01-01

The implant-bone interface is the scene of competition between microorganisms and distinct types of tissue cells. In the past, various strategies have been followed to support bony integration and to prevent bacterial implant-associated infections. In the present study we investigated the biological properties of diamond-like carbon (DLC) surfaces containing silver nanoparticles. DLC is a promising material for the modification of medical implants providing high mechanical and chemical stability and a high degree of biocompatibility. DLC surface modifications with varying silver concentrations were generated on medical-grade titanium discs, using plasma immersion ion implantation-induced densification of silver nanoparticle-containing polyvinylpyrrolidone polymer solutions. Immersion of implants in aqueous liquids resulted in a rapid silver release reducing the growth of surface-bound and planktonic Staphylococcus aureus and Staphylococcus epidermidis. Due to the fast and transient release of silver ions from the modified implants, the surfaces became biocompatible, ensuring growth of mammalian cells. Human endothelial cells retained their cellular differentiation as indicated by the intracellular formation of Weibel-Palade bodies and a high responsiveness towards histamine. Our findings indicate that the integration of silver nanoparticles into DLC prevents bacterial colonization due to a fast initial release of silver ions, facilitating the growth of silver susceptible mammalian cells subsequently. PMID:26955791

Silver nanoparticle-enriched diamond-like carbon implant modification as a mammalian cell compatible surface with antimicrobial properties

NASA Astrophysics Data System (ADS)

Gorzelanny, Christian; Kmeth, Ralf; Obermeier, Andreas; Bauer, Alexander T.; Halter, Natalia; Kümpel, Katharina; Schneider, Matthias F.; Wixforth, Achim; Gollwitzer, Hans; Burgkart, Rainer; Stritzker, Bernd; Schneider, Stefan W.

2016-03-01

The implant-bone interface is the scene of competition between microorganisms and distinct types of tissue cells. In the past, various strategies have been followed to support bony integration and to prevent bacterial implant-associated infections. In the present study we investigated the biological properties of diamond-like carbon (DLC) surfaces containing silver nanoparticles. DLC is a promising material for the modification of medical implants providing high mechanical and chemical stability and a high degree of biocompatibility. DLC surface modifications with varying silver concentrations were generated on medical-grade titanium discs, using plasma immersion ion implantation-induced densification of silver nanoparticle-containing polyvinylpyrrolidone polymer solutions. Immersion of implants in aqueous liquids resulted in a rapid silver release reducing the growth of surface-bound and planktonic Staphylococcus aureus and Staphylococcus epidermidis. Due to the fast and transient release of silver ions from the modified implants, the surfaces became biocompatible, ensuring growth of mammalian cells. Human endothelial cells retained their cellular differentiation as indicated by the intracellular formation of Weibel-Palade bodies and a high responsiveness towards histamine. Our findings indicate that the integration of silver nanoparticles into DLC prevents bacterial colonization due to a fast initial release of silver ions, facilitating the growth of silver susceptible mammalian cells subsequently.

Silver nanoparticle-enriched diamond-like carbon implant modification as a mammalian cell compatible surface with antimicrobial properties.

PubMed

Gorzelanny, Christian; Kmeth, Ralf; Obermeier, Andreas; Bauer, Alexander T; Halter, Natalia; Kümpel, Katharina; Schneider, Matthias F; Wixforth, Achim; Gollwitzer, Hans; Burgkart, Rainer; Stritzker, Bernd; Schneider, Stefan W

2016-03-09

The implant-bone interface is the scene of competition between microorganisms and distinct types of tissue cells. In the past, various strategies have been followed to support bony integration and to prevent bacterial implant-associated infections. In the present study we investigated the biological properties of diamond-like carbon (DLC) surfaces containing silver nanoparticles. DLC is a promising material for the modification of medical implants providing high mechanical and chemical stability and a high degree of biocompatibility. DLC surface modifications with varying silver concentrations were generated on medical-grade titanium discs, using plasma immersion ion implantation-induced densification of silver nanoparticle-containing polyvinylpyrrolidone polymer solutions. Immersion of implants in aqueous liquids resulted in a rapid silver release reducing the growth of surface-bound and planktonic Staphylococcus aureus and Staphylococcus epidermidis. Due to the fast and transient release of silver ions from the modified implants, the surfaces became biocompatible, ensuring growth of mammalian cells. Human endothelial cells retained their cellular differentiation as indicated by the intracellular formation of Weibel-Palade bodies and a high responsiveness towards histamine. Our findings indicate that the integration of silver nanoparticles into DLC prevents bacterial colonization due to a fast initial release of silver ions, facilitating the growth of silver susceptible mammalian cells subsequently.

The pathway to intelligent implants: osteoblast response to nano silicon-doped hydroxyapatite patterning

PubMed Central

Munir, G.; Koller, G.; Di Silvio, L.; Edirisinghe, M. J.; Bonfield, W.; Huang, J.

2011-01-01

Bioactive hydroxyapatite (HA) with addition of silicon (Si) in the crystal structure (silicon-doped hydroxyapatite (SiHA)) has become a highly attractive alternative to conventional HA in bone replacement owing to the significant improvement in the in vivo bioactivity and osteoconductivity. Nanometre-scaled SiHA (nanoSiHA), which closely resembles the size of bone mineral, has been synthesized in this study. Thus, the silicon addition provides an extra chemical cue to stimulate and enhance bone formation for new generation coatings, and the next stage in metallic implantation design is to further improve cellular adhesion and proliferation by control of cell alignment. Topography has been found to provide a powerful set of signals for cells and form contact guidance. Using the recently developed novel technique of template-assisted electrohydrodynamic atomization (TAEA), patterns of pillars and tracks of various dimensions of nanoSiHA were achieved. Modifying the parameters of TAEA, the resolution of pattern structures was controlled, enabling the topography of a substrate to be modified accordingly. Spray time, flow rate and distance between the needle and substrate were varied to improve the pattern formation of pillars and tracks. The 15 min deposition time provided the most consistent patterned topography with a distance of 50 mm and flow rate of 4 µl min−1. A titanium substrate was patterned with pillars and tracks of varying widths, line lengths and distances under the optimized TAEA processing condition. A fast bone-like apatite formation rate was found on nanoSiHA after immersion in simulated body fluid, thus demonstrating its high in vitro bioactivity. Primary human osteoblast (HOB) cells responded to SiHA patterns by stretching of the filopodia between track and pillar, attaching to the apex of the pillar pattern and stretching between two. HOB cells responded to the track pattern by elongating along and between the track, and the length of HOB cells was proportional to the gaps between track patterns, but this relationship was not observed on the pillar patterns. The study has therefore provided an insight for future design of next generation implant surfaces to control and guide cellular responses, while TAEA patterning provides a controllable technique to provide topography to medical implants. PMID:21208969

Histone deacetylase inhibitors restore IL-10 expression in lipopolysaccharide-induced cell inflammation and reduce IL-1β and IL-6 production in breast silicone implant in C57BL/6J wild-type murine model.

PubMed

Di Liddo, Rosa; Valente, Sergio; Taurone, Samanta; Zwergel, Clemens; Marrocco, Biagina; Turchetta, Rosaria; Conconi, Maria Teresa; Scarpa, Carlotta; Bertalot, Thomas; Schrenk, Sandra; Mai, Antonello; Artico, Marco

2016-01-20

Among epigenetic enzymes, histone deacetylases (HDACs) are responsible for regulating the expression of an extensive array of genes by reversible deacetylation of nuclear histones as well as a large number of non-histone proteins. Initially proposed for cancer therapy, recently the interest for HDAC inhibitors (HDACi) as orally active, safe, and anti-inflammatory agents is rising due to their ability in reducing the severity of inflammatory and autoimmune diseases. In particular, selective HDAC3, HDAC6, and HDAC8 inhibitors have been described to downregulate the expression of pro-inflammatory cytokines (TNF-α, TGF-β, IL-1β, and IL-6). Herein, using KB31, C2C12, and 3T3-J2 cell lines, we demonstrated that, under lipopolysaccharide-induced in vitro inflammation, HDAC3/6/8 inhibitor MC2625 and HDAC6-selective inhibitor MC2780 were effective at a concentration of 30 ng/mL to downregulate mRNA expression of pro-inflammatory cytokines (IL-1β and IL-6) and to promote the transcription of IL-10 gene, without affecting the cell viability. Afterwards, we investigated by immunohistochemistry the activity of MC2625 and MC2780 at a concentration of 60 ng/kg animal weight to regulate silicone-triggered immune response in C57BL/6J female mice. Our findings evidenced the ability of such inhibitors to reduce host inflammation in silicone implants promoting a thickness reduction of peri-implant fibrous capsule, upregulating IL-10 expression, and reducing the production of both IL-1β and IL-6. These results underline the potential application of MC2625 and MC2780 in inflammation-related diseases.

Preparation, characterization, and biological properties of organic-inorganic nanocomposite coatings on titanium substrates prepared by sol-gel.

PubMed

Catauro, Michelina; Bollino, Flavia; Papale, Ferdinando

2014-02-01

When surface-reactive (bioactive) coatings are applied to medical implants by means of the sol-gel dip-coating technique, the biological proprieties of the surface of the implant can be locally modified to match the properties of the surrounding tissues to provide a firm fixation of the implant. The aim of this study has been to synthesize, via sol-gel, organoinorganic nanoporous materials and to dip-coat a substrate to use in dental applications. Different systems have been prepared consisting of an inorganic zirconium-based matrix, in which a biodegradable polymer, the poly-ε-caprolactone was incorporated in different percentages. The materials synthesized by the sol-gel process, before gelation, when they were still in sol phase, have been used to coat a titanium grade 4 (Ti-4) substrate to change its surface biological properties. Thin films have been obtained by means of the dip-coating technique. A microstructural analysis of the obtained coatings was performed using scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy. The biological proprieties have been investigated by means of tests in vitro. The bone-bonding capability of the nanocomposite films has been evaluated by examining the appearance of apatite on their surface when plunged in a simulated body fluid (SBF) with ion concentrations nearly equal to those of human blood plasma. The examination of apatite formation on the nanocomposites, after immersion in SBF, has been carried out by SEM equipped with energy-dispersive X-ray spectroscopy. To evaluate cells-materials interaction, human osteosarcoma cell line (Saos-2) has been seeded on specimens and cell vitality evaluated by WST-8 assay. © 2013 Wiley Periodicals, Inc.

Recombinant interleukin-12 and interleukin-18 antitumor therapy in a guinea-pig hepatoma cell implant model.

PubMed

Shiratori, Ikuo; Suzuki, Yasuhiko; Oshiumi, Hiroyuki; Begum, Nasim A; Ebihara, Takashi; Matsumoto, Misako; Hazeki, Kaoru; Kodama, Ken; Kashiwazaki, Yasuo; Seya, Tsukasa

2007-12-01

Interleukin (IL)-12 and IL-18 are secreted by myeloid cells activated with adjuvants such as Bacillus Calmette-Guérin (BCG) cell wall. They induce T-helper 1 polarization in the host immune system and upregulate production of lymphocyte interferon-gamma, which leads to the induction of an antitumor gene program. It has been reported that humans have an immune system that more closely resembles that of the guinea pig in adjuvant-response features rather than the mouse system, which prevents the mouse results being extrapolated to human immunotherapy. Here we have constructed a tumor-implant system in guinea pigs to evaluate the antitumor potential of guinea pig IL-12 (gpIL-12) and guinea pig IL-18 (gpIL-18). Purified recombinant gpIL-12 and gpIL-18 were prepared and applied intraperitoneally to tumor-bearing (line 10 hepatoma) guinea pigs as the basis of the adjuvant immunotherapy. Intraperitoneal administration of gpIL-12 and gpIL-18 led to retardation of primary tumor growth and suppression of lymph-node metastasis in tumor-bearing guinea pigs. The permissible range of IL-12 appeared wider in guinea pigs than in mice. Even at an IL-12 dose higher than that in mice, there was no evidence of side-effects until day 26, when the guinea pigs were killed. gpIL-18 augmented the antitumor effect of gpIL-12 but exerted less ability to suppress lymph-node metastasis. The effects of gpIL-12 and gpIL-18 on the tumors implanted in guinea pigs will encourage us to use IL-12- and IL-18-inducible adjuvants for immunotherapy in human patients with solid cancer.

Adherent endotoxin on dental implant surfaces: a reappraisal.

PubMed

Morra, Marco; Cassinelli, Clara; Bollati, Daniele; Cascardo, Giovanna; Bellanda, Marco

2015-02-01

Osteoimmunology is the crosstalk between cells from the immune and skeletal systems, suggesting a role of pro-inflammatory cytokines in the stimulation of osteoclast activity. Endotoxin or bacterial challenges to inflammatory cells are directly relevant to dental implant pathologies involving bone resorption, such as osseointegration failure and peri-implantitis. While the endotoxin amount on implant devices is regulated by standards, it is unknown whether commercially available dental implants elicit different levels of adherent-endotoxin stimulated cytokines. The objective of this work is to develop a model system and evaluate endotoxin-induced expression of pro-inflammatory cytokine genes relevant to osteoclast activation on commercially available dental implants. Murine J774-A1 macrophages were cultured on Ti disks with different level of lipopolysaccharide (LPS) contamination to define the time-course of the inflammatory response to endotoxin, as evaluated by reverse transcription polymerase chain reaction analysis. The developed protocol was then used to measure adherent endotoxin on commercially available packaged and sterile dental implants in the "as-implanted" condition. Results show that tested dental implants induce variable expression of endotoxin-stimulated genes, sometimes above the level expected to promote bone resorption in vivo. Results are unaffected by the specific surface treatment; rather, they likely reflect care in cleaning and packaging protocols. In conclusion, expression of genes that enhance osteoclast activity through endotoxin stimulation of inflammatory cells is widely different on commercially available dental implants. A reappraisal of the clinical impact of adherent endotoxins on dental (and bone) implant devices is required in light of increasing knowledge on crosstalk between cells from the immune and skeletal systems.

Strong and rapid induction of osteoblast differentiation by Cbfa1/Til-1 overexpression for bone regeneration.

PubMed

Kojima, Hiroko; Uemura, Toshimasa

2005-01-28

Core binding factor alpha-1 (Cbfa1), known as an essential transcription factor for osteogenic lineage, has two major N-terminal isoforms: Pebp2alphaA and Til-1. To study the roles of these isoforms in bone regeneration, we applied an adenoviral vector carrying their genes to transduce primary osteoprogenitor cells in vitro and in vivo. Overexpression of the two isoforms induced rapid and marked osteoblast differentiation, with Til-1 being more effective in vitro, by examination of the alkaline phosphatase activity, calcium content, and Alizarin red staining. Til-1 overexpressing cells/porous ceramic composites were transplanted into subcutaneous and bone defect sites in Fischer rats (cultured bone transplantation model) and markedly affected in vivo bone formation and osteoblast markers. The results demonstrated that the reconstitution of bone tissues, such as cortical bone and trabecular bone was accelerated by implantation of Til-1 overexpressing cells/porous ceramic composites. Moreover, the new bone formation by Til-1 overexpression appeared to reflect replacement of new bone within the implant boundaries. To ascertain whether implanted Cbfa1 overexpressing cells could differentiate into osteogenic cells to create bone or whether it stimulated the surrounding recipient tissue to regenerate bone, implanted male donor cells were visualized by fluorescent in situ hybridization analysis. The proportion of implanted cells in the presumptive bone forming region was over 80% and did not change throughout from 3 days to 8 weeks after implantation. These findings suggested that the newly formed bone in the porous area of the scaffold is mostly produced by the implanted donor cells or their derived cells, effectively by Til-1 overexpression.

Implanted Cell-Dense Prevascularized Tissues Develop Functional Vasculature That Supports Reoxygenation After Thrombosis

PubMed Central

White, Sean M.; Pittman, Chelsea R.; Hingorani, Ryan; Arora, Rajan; Esipova, Tatiana V.; Vinogradov, Sergei A.; Hughes, Christopher C.W.; Choi, Bernard

2014-01-01

Achieving adequate vascularization within implanted engineered tissues is a significant obstacle to maintaining viability and functionality. In vitro prevascularization of engineered tissues has been explored as a potential solution to this challenge. The traditional paradigm of in vitro prevascularization is to implant an engineered tissue with a preformed vascular network that is perfused after anastomosis with the host circulation. We investigated the efficacy of this strategy by implanting cell-dense prevascularized tissues created via cell-mediated contraction and composed of collagen and a collagen-fibrin mixture into dorsal window chambers surgically prepared on immunocompromised mice. We found that host-implant anastomosis takes place in 2–6 days and that perfusion of vessels within the implants is subsequently restricted by thrombosis. However, by day 7, a functional vascular network composed of host and implant vessels developed. Prevascularization enhanced intra-implant pO2 significantly as early as 2 days postimplantation, reaching a maximum of 55 mmHg by day 8, which was significantly greater than the maximum within cellularized control tissues (18 mmHg). By day 14, collagen tissues supported ∼0.51×109 implanted and host-derived cells per mL. Our findings elucidate key features of in vitro prevascularization that can be used toward the design of larger and more functionally complex engineered tissues. PMID:24593148

Maintenance of human hyperplastic prostate implants at different sites in athymic mice.

PubMed

Soós, G; Debiec-Rychter, M; Jones, R F; Zukowski, K; Haas, G P; Wang, C Y

1995-01-01

The present study determined the influence of implantation sites, androgens, and the graft's fibrovascular elements on the maintenance of epithelial elements of human benign hyperplastic prostate tissue (BPH) in the nude mouse. BPH fragments prepared from fresh surgical specimens were implanted subcutaneously (s.c.), intraperitoneally (i.p.), or under the renal capsules (r.c.) into male Beige nude mice, which had been implanted s.c. with a Silastic tube filled with 4-dihydrotestosterone (DHT) or cholesterol. Two weeks later the BPH tissues were removed from the mouse and examined microscopically. The implants from all three sites maintained a comparable morphology, with epithelial and/or angio-leiomyomatous stromal hyperplastic appearance, without striking signs of atrophy, irrespective of supplementation with DHT. Expression of proliferating cell nuclear antigen in the implants was comparable, indicating that there was no significant influence of implantation site on the proliferative ability of either epithelia or the stromal fibroblasts. The PCNA-positive cells in the implants, including the vascular and myofibrous elements, hybridized in situ to a human-specific repeated-sequence DNA probe, indicating that these proliferating cells were of human origin. Our data suggest that during the early phases of the adaptation and maintenance of BPH implants, survival of epithelial cells is actively supported by fibro-vascular mesenchymal elements of the prostate grafts in a manner apparently unaffected by DHT supplements.

Breast implants and possible association with ALCL: A retrospective study including a histological analysis of 296 explanted breast tissues and current literature.

PubMed

Kuehlmann, Britta; Prantl, Lukas

2016-10-05

To identify a possible connection between anaplastic large cell lymphoma and different types of breast implants. We conducted a retrospective evaluation of 296 breast tissues of 227 women with different breast implant types undergoing surgical revision or explantation between January 2000 and June 2015. Histological and selected immunohistochemical analyses of CD30-&ALK-1-markers of the breast capsules were performed. The womens' average age was 42.91±12.66 years (median: 43.83 years) during implantation and 51.40±11.40 years (median: 52.37 years) during revision or explantation of the implants. Average implant residing time was 8.49±8.90 years (median: 5.83 years). In 51% implantation was for reconstructive, in 48% for aesthetic reasons, in 1% for other reasons. At 59% the main reason for explantation or removal was capsular fibrosis (n = 173). In 296 breast capsules we could not find pathological lymphoma cells according to ALCL, retrospectively. In our study we detected high incidences of various cells in relationship to the implant's type and residing time, which will be published in further articles. We could not find ALCL-cells in breast capsules of explanted or revised breast implants during 2000-2015, retrospectively.There should be a heightened awareness of a possible relationship between the development of cancer and breast implants. To date there are case reports about a possible association between the development of ALCL and breast implants. The number of cases are few and our knowledge of the pathogenesis is little. Further investigation is needed to understand the possible link between breast implants and ALCL found in the breast.

Modulation of human dermal microvascular endothelial cell and human gingival fibroblast behavior by micropatterned silica coating surfaces for zirconia dental implant applications

PubMed Central

Laranjeira, Marta S; Carvalho, Ângela; Pelaez-Vargas, Alejandro; Hansford, Derek; Ferraz, Maria Pia; Coimbra, Susana; Costa, Elísio; Santos-Silva, Alice; Fernandes, Maria Helena; Monteiro, Fernando Jorge

2014-01-01

Dental ceramic implants have shown superior esthetic behavior and the absence of induced allergic disorders when compared to titanium implants. Zirconia may become a potential candidate to be used as an alternative to titanium dental implants if surface modifications are introduced. In this work, bioactive micropatterned silica coatings were produced on zirconia substrates, using a combined methodology of sol–gel processing and soft lithography. The aim of the work was to compare the in vitro behavior of human gingival fibroblasts (HGFs) and human dermal microvascular endothelial cells (HDMECs) on three types of silica-coated zirconia surfaces: flat and micropatterned (with pillars and with parallel grooves). Our results showed that cells had a higher metabolic activity (HGF, HDMEC) and increased gene expression levels of fibroblast-specific protein-1 (FSP-1) and collagen type I (COL I) on surfaces with pillars. Nevertheless, parallel grooved surfaces were able to guide cell growth. Even capillary tube-like networks of HDMEC were oriented according to the surface geometry. Zirconia and silica with different topographies have shown to be blood compatible and silica coating reduced bacteria adhesion. All together, the results indicated that microstructured bioactive coating seems to be an efficient strategy to improve soft tissue integration on zirconia implants, protecting implants from peri-implant inflammation and improving long-term implant stabilization. This new approach of micropatterned silica coating on zirconia substrates can generate promising novel dental implants, with surfaces that provide physical cues to guide cells and enhance their behavior. PMID:27877662

Modulation of human dermal microvascular endothelial cell and human gingival fibroblast behavior by micropatterned silica coating surfaces for zirconia dental implant applications

NASA Astrophysics Data System (ADS)

Laranjeira, Marta S.; Carvalho, Ângela; Pelaez-Vargas, Alejandro; Hansford, Derek; Ferraz, Maria Pia; Coimbra, Susana; Costa, Elísio; Santos-Silva, Alice; Fernandes, Maria Helena; Monteiro, Fernando Jorge

2014-04-01

Dental ceramic implants have shown superior esthetic behavior and the absence of induced allergic disorders when compared to titanium implants. Zirconia may become a potential candidate to be used as an alternative to titanium dental implants if surface modifications are introduced. In this work, bioactive micropatterned silica coatings were produced on zirconia substrates, using a combined methodology of sol-gel processing and soft lithography. The aim of the work was to compare the in vitro behavior of human gingival fibroblasts (HGFs) and human dermal microvascular endothelial cells (HDMECs) on three types of silica-coated zirconia surfaces: flat and micropatterned (with pillars and with parallel grooves). Our results showed that cells had a higher metabolic activity (HGF, HDMEC) and increased gene expression levels of fibroblast-specific protein-1 (FSP-1) and collagen type I (COL I) on surfaces with pillars. Nevertheless, parallel grooved surfaces were able to guide cell growth. Even capillary tube-like networks of HDMEC were oriented according to the surface geometry. Zirconia and silica with different topographies have shown to be blood compatible and silica coating reduced bacteria adhesion. All together, the results indicated that microstructured bioactive coating seems to be an efficient strategy to improve soft tissue integration on zirconia implants, protecting implants from peri-implant inflammation and improving long-term implant stabilization. This new approach of micropatterned silica coating on zirconia substrates can generate promising novel dental implants, with surfaces that provide physical cues to guide cells and enhance their behavior.

Impurity-defect complexes in non-implanted aluminum

NASA Astrophysics Data System (ADS)

Pedersen, F. T.; Grann, H.; Weyer, G.

1986-02-01

The formation of impurity-defect complexes in ion-implanted aluminum has been studied in the temperature interval 100 400K. Radioactive119In isotopes have been implanted. Mössbauer spectra have been measured for the 24 keV γ-radiation emitted after the decay to119Sn. The spectra could be analysed satisfactorily with two lines, one of which is known to be due to substitutional Sn. A second line, which has a higher isomer shift and lower Debye temperature, is tentatively assigned to vacancy-associated Sn, formed by trapping of thermally mobile (multi-)vacancies. Comparison to similar DPAC experiments suggests that cubic Sn-V4 complexes are formed. Some indication (˜15%) for an athermal formation of impurity defects below 175K is obtained.

NMR Observation of Mobile Protons in Proton-Implanted ZnO Nanorods

PubMed Central

Park, Jun Kue; Kwon, Hyeok-Jung; Lee, Cheol Eui

2016-01-01

The diffusion properties of H+ in ZnO nanorods are investigated before and after 20 MeV proton beam irradiation by using 1H nuclear magnetic resonance (NMR) spectroscopy. Herein, we unambiguously observe that the implanted protons occupy thermally unstable site of ZnO, giving rise to a narrow NMR line at 4.1 ppm. The activation barrier of the implanted protons was found to be 0.46 eV by means of the rotating-frame spin-lattice relaxation measurements, apparently being interstitial hydrogens. High-energy beam irradiation also leads to correlated jump diffusion of the surface hydroxyl group of multiple lines at ~1 ppm, implying the presence of structural disorder at the ZnO surface. PMID:26988733

Revascularization of decellularized lung scaffolds: principles and progress

PubMed Central

Stabler, Collin T.; Lecht, Shimon; Mondrinos, Mark J.; Goulart, Ernesto; Lazarovici, Philip

2015-01-01

There is a clear unmet clinical need for novel biotechnology-based therapeutic approaches to lung repair and/or replacement, such as tissue engineering of whole bioengineered lungs. Recent studies have demonstrated the feasibility of decellularizing the whole organ by removal of all its cellular components, thus leaving behind the extracellular matrix as a complex three-dimensional (3D) biomimetic scaffold. Implantation of decellularized lung scaffolds (DLS), which were recellularized with patient-specific lung (progenitor) cells, is deemed the ultimate alternative to lung transplantation. Preclinical studies demonstrated that, upon implantation in rodent models, bioengineered lungs that were recellularized with airway and vascular cells were capable of gas exchange for up to 14 days. However, the long-term applicability of this concept is thwarted in part by the failure of current approaches to reconstruct a physiologically functional, quiescent endothelium lining the entire vascular tree of reseeded lung scaffolds, as inferred from the occurrence of hemorrhage into the airway compartment and thrombosis in the vasculature in vivo. In this review, we explore the idea that successful whole lung bioengineering will critically depend on 1) preserving and/or reestablishing the integrity of the subendothelial basement membrane, especially of the ultrathin respiratory membrane separating airways and capillaries, during and following decellularization and 2) restoring vascular physiological functionality including the barrier function and quiescence of the endothelial lining following reseeding of the vascular compartment. We posit that physiological reconstitution of the pulmonary vascular tree in its entirety will significantly promote the clinical translation of the next generation of bioengineered whole lungs. PMID:26408553

Anti-invasive and antiangiogenic effects of MMI-166 on malignant glioma cells

PubMed Central

2010-01-01

Background The constitutive overexpression of matrix metalloproteinases (MMPs) is frequently observed in malignant tumours. In particular, MMP-2 and MMP-9 have been reported to be closely associated with invasion and angiogenesis in malignant gliomas. Our study aimed to evaluate the antitumour effects of MMI-166 (Nalpha-[4-(2-Phenyl-2H- tetrazole-5-yl) phenyl sulfonyl]-D-tryptophan), a third generation MMP inhibitor, on three human glioma cell lines (T98G, U87MG, and ONS12) in vitro and in vivo. Methods The effects of MMI-166 on the gelatinolytic activity was analysed by gelatine zymography. The anti-invasive effect of MMI-166 was analysed by an in vitro invasion assay. An in vitro angiogenesis assay was also performed. In vitro growth inhibition of glioma cells by MMI-166 was determined by the MTT assay. The effect of MMI-166 on an orthotropic implantation model using athymic mice was also evaluated. Results Gelatine zymography revealed that MMP-2 and MMP-9 activities were suppressed by MMI-166. The invasion of glioma cells was suppressed by MMI-166. The angiogenesis assay showed that MMI-166 had a suppressive effect on glioma cell-induced angiogenesis. However, MMI-166 did not suppress glioma cell proliferation in the MTT assay. In vivo, MMI-166 suppressed tumour growth in athymic mice implanted orthotropically with T98G cells and showed an inhibitory effect on tumour-induced angiogenesis and tumour growth. This is the first report of the effect of a third generation MMP inhibitor on malignant glioma cells. Conclusions These results suggest that MMI-166 may have potentially suppressive effects on the invasion and angiogenesis of malignant gliomas. PMID:20587068

A Real-Time Non-invasive Auto-bioluminescent Urinary Bladder Cancer Xenograft Model.

PubMed

John, Bincy Anu; Xu, Tingting; Ripp, Steven; Wang, Hwa-Chain Robert

2017-02-01

The study was to develop an auto-bioluminescent urinary bladder cancer (UBC) xenograft animal model for pre-clinical research. The study used a humanized, bacteria-originated lux reporter system consisting of six (luxCDABEfrp) genes to express components required for producing bioluminescent signals in human UBC J82, J82-Ras, and SW780 cells without exogenous substrates. Immune-deficient nude mice were inoculated with Lux-expressing UBC cells to develop auto-bioluminescent xenograft tumors that were monitored by imaging and physical examination. Lux-expressing auto-bioluminescent J82-Lux, J82-Ras-Lux, and SW780-Lux cell lines were established. Xenograft tumors derived from tumorigenic Lux-expressing auto-bioluminescent J82-Ras-Lux cells allowed a serial, non-invasive, real-time monitoring by imaging of tumor development prior to the presence of palpable tumors in animals. Using Lux-expressing auto-bioluminescent tumorigenic cells enabled us to monitor the entire course of xenograft tumor development through tumor cell implantation, adaptation, and growth to visible/palpable tumors in animals.

Antiproliferative and proapoptotic effects of bisphenol A on human trophoblastic JEG-3 cells.

PubMed

Morice, Lucie; Benaîtreau, Delphine; Dieudonné, Marie-Noëlle; Morvan, Corinne; Serazin, Valérie; de Mazancourt, Philippe; Pecquery, René; Dos Santos, Esther

2011-07-01

Different studies performed in rodents revealed that bisphenol-A (BPA), an environmental compound, altered early embryonic development. However, little is known concerning the direct effects of BPA on human implantation process. Thus, we decided to study in vitro BPA's effects on proliferative capacities of the human trophoblastic cell line, JEG-3. For this purpose, we first have shown that JEG-3 cells express the specific BPA receptor, namely estrogen-related receptor γ1 (ERRγ1). Secondly, we demonstrated that BPA did not exert any cytotoxic action in JEG-3 cells up to 10(-6)M. Moreover [(3)H]-thymidine incorporation experiments revealed that BPA significantly reduced cell proliferation. The results also showed that BPA induced JEG-3 apoptosis capacity as reflected by DNA fragmentation experiments. In conclusion, we describe here the direct impact of BPA on trophoblastic cell number mediated through both anti-proliferative and pro-apoptotic effects. Copyright © 2011 Elsevier Inc. All rights reserved.

Warfarin affects acute inflammatory response induced by subcutaneous polyvinyl sponge implantation in rats.

PubMed

Mirkov, Ivana; Popov Aleksandrov, Aleksandra; Demenesku, Jelena; Ninkov, Marina; Mileusnic, Dina; Kataranovski, Dragan; Kataranovski, Milena

2017-09-01

Warfarin (WF) is an anticoagulant which also affects physiological processes other than hemostasis. Our previous investigations showed the effect of WF which gained access to the organism via skin on resting peripheral blood granulocytes. Based on these data, the aim of the present study was to examine whether WF could modulate the inflammatory processes as well. To this aim the effect of WF on the inflammatory response induced by subcutaneous sponge implantation in rats was examined. Warfarin-soaked polyvinyl sponges (WF-sponges) were implanted subcutaneously and cell infiltration into sponges, the levels of nitric oxide (NO) and inflammatory cytokines tumor necrosis factor (TNF) and interleukin-6 (IL-6) production by sponge cells were measured as parameters of inflammation. T cell infiltration and cytokine interferon-γ (IFN-γ), interleukin-17 (IL-17) and interleukin-10 (IL-10) were measured at day 7 post implantation. Warfarin exerted both stimulatory and suppressive effects depending on the parameter examined. Flow cytometry of cells recovered from sponges showed higher numbers of granulocytes (HIS48 + cells) at days 1 and 3 post implantation and CD11b + cells at day 1 compared to control sponges. Cells from WF-sponges had an increased NO production (Griess reaction) at days 1 and 7. In contrast, lower levels of TNF (measured by ELISA) production by cells recovered from WF-soaked sponges were found in the early (day one) phase of reaction with unchanged levels at other time points. While IL-6 production by cells recovered from WF-soaked sponges was decreased at day 1, it was increased at day 7. Higher T cell numbers were noted in WF sponges at day 7 post implantation, and recovered cells produced more IFN-γ and IL-17, while IL-10 production remained unchanged. Warfarin affects some of the parameters of inflammatory reaction induced by subcutaneous polyvinyl sponge implantation. Differential (both stimulatory as well as inhibitory) effects of WF on inflammatory response to sponge implants might affect the course and/or duration of this reaction.

Development and fabrication of a solar cell junction processing system

NASA Technical Reports Server (NTRS)

Bunker, S.

1981-01-01

A solar cell junction processing system was developed and fabricated. A pulsed electron beam for the four inch wafers is being assembled and tested, wafers were successfully pulsed, and solar cells fabricated. Assembly of the transport locks is completed. The transport was operated successfully but not with sufficient reproducibility. An experiment test facility to examine potential scaleup problems associated with the proposed ion implanter design was constructed and operated. Cells were implanted and found to have efficiency identical to the normal Spire implant process.

Investigation of the effect of doping of Cr2O3 on bioactivity properties of the SiO2-CaO-P2O5 bioceramics

NASA Astrophysics Data System (ADS)

Sarin, Nonita; Singh, K. J.; Kaur, Kulwinder; Anand, Vikas; Kaur, Raminderjit; Singh, Jatinder

2018-05-01

Due to better biocompatibility among various types of biomaterials, bioceramics have been found to be useful for the repair of damaged bone tissues. Authors have prepared bioceramics of the composition xCr2O3-(40-x) SiO2- 40CaO-20P2O5(where, x = 0 and 2 mole %) by using sol gel technique. Prepared samples have been assessed for their bioactivity and cell viability with the help of X-ray diffraction, Fourier transform infrared and MG63 cell line. The aim of this study is to estimate the practical utility of the prepared samples as successful implant materials in human body.

Efficient systemic DNA delivery to the tumor by self-assembled nanoparticle

NASA Astrophysics Data System (ADS)

Tang, Hailin; Xie, Xinhua; Guo, Jiaoli; Wei, Weidong; Wu, Minqing; Liu, Peng; Kong, Yanan; Yang, Lu; Hung, Mien-Chie; Xie, Xiaoming

2014-01-01

There are few delivery agents that could deliver gene with high efficiency and low toxicity, especially for animal experiments. Therefore, creating vectors with good delivery efficiency and safety profile is a meaningful work. We have developed a self-assembled gene delivery system (XM001), which can more efficiently deliver DNA to multiple cell lines and breast tumor, as compared to commercial delivery agents. In addition, systemically administrated XM001-BikDD (BikDD is a mutant form of proapoptotic gene Bik) significantly inhibited the growth of human breast cancer cells and prolonged the life span in implanted nude mice. This study demonstrates that XM001 is an efficient and widespread transfection agent, which could be a promising tumor delivery vector for cancer targeted therapy.

Corticotropin-Releasing Hormone Modulates Human Trophoblast Invasion through Carcinoembryonic Antigen-Related Cell Adhesion Molecule-1 Regulation

PubMed Central

Bamberger, Ana-Maria; Minas, Vassilis; Kalantaridou, Sophia N.; Radde, Jessica; Sadeghian, Helen; Löning, Thomas; Charalampopoulos, Ioannis; Brümmer, Jens; Wagener, Christoph; Bamberger, Christoph M.; Schulte, Heinrich M.; Chrousos, George P.; Makrigiannakis, Antonis

2006-01-01

Abnormalities in the process of trophoblast invasion may result in abnormal placentation. Both the embryonic trophoblast and maternal decidua produce corticotropin-releasing hormone (CRH), which promotes implantation. Carcinoembryonic antigen-related cell adhesion molecule 1 (CEACAM1), which is expressed in extravillous trophoblasts (EVTs) of normal human placenta, may also function in tro-phoblast/endometrial interactions. We investigated whether locally produced CRH plays a role in trophoblast invasion, primarily by regulating CEACAM1 expression. We examined cultures of freshly isolated human EVTs, which express CEACAM1, and an EVT-based hybridoma cell line, which is devoid of endogenous CEACAM1. CRH inhibited EVT invasion in Matrigel invasion assays, and this effect was blocked by the CRH receptor type 1 (CRHR1)-specific antagonist antalarmin. Additionally, CRH decreased CEACAM1 expression in EVTs in a dose-dependent manner. After transfection of the hybridoma cell line with a CEACAM1 expression vector, the invasiveness of these cells was strongly enhanced. This effect was inhibited by addition of blocking monoclonal antibody against CEACAM1. Furthermore, blocking of endogenous CEACAM1 in EVTs inhibited the invasive potential of these cells. Taken together these findings suggest that CRH inhibits trophoblast invasion by decreasing the expression of CEACAM1 through CRHR1, an effect that might be involved in the pathophysiology of clinical conditions, such as preeclampsia and placenta accreta. PMID:16400017

Surface Modifications of Titanium Implants by Multilayer Bioactive Coatings with Drug Delivery Potential: Antimicrobial, Biological, and Drug Release Studies

NASA Astrophysics Data System (ADS)

Ordikhani, Farideh; Zustiak, Silviya Petrova; Simchi, Abdolreza

2016-04-01

Recent strategies to locally deliver antimicrobial agents to combat implant-associated infections—one of the most common complications in orthopedic surgery—are gaining interest. However, achieving a controlled release profile over a desired time frame remains a challenge. In this study, we present an innovative multifactorial approach to combat infections which comprises a multilayer chitosan/bioactive glass/vancomycin nanocomposite coating with an osteoblastic potential and a drug delivery capacity. The bioactive drug-eluting coating was prepared on the surface of titanium foils by a multistep electrophoretic deposition technique. The adopted deposition strategy allowed for a high antibiotic loading of 1038.4 ± 40.2 µg/cm2. The nanocomposite coating exhibited a suppressed burst release with a prolonged sustained vancomycin release for up to 6 weeks. Importantly, the drug release profile was linear with respect to time, indicating a zero-order release kinetics. An in vitro bactericidal assay against Staphylococcus aureus confirmed that releasing the drug reduced the risk of bacterial infection. Excellent biocompatibility of the developed coating was also demonstrated by in vitro cell studies with a model MG-63 osteoblast cell line.

Effect of the deposition temperature on corrosion resistance and biocompatibility of the hydroxyapatite coatings

NASA Astrophysics Data System (ADS)

Vladescu, A.; Braic, M.; Azem, F. Ak; Titorencu, I.; Braic, V.; Pruna, V.; Kiss, A.; Parau, A. C.; Birlik, I.

2015-11-01

Hydroxyapatite (HAP) ceramics belong to a class of calcium phosphate-based materials, which have been widely used as coatings on titanium medical implants in order to improve bone fixation and thus to increase the lifetime of the implant. In this study, HAP coatings were deposited from pure HAP targets on Ti6Al4V substrates using the radio-frequency magnetron sputtering technique at substrate temperatures ranging from 400 to 800 °C. The surface morphology and the crystallographic structure of the films were investigated by atomic force microscopy (AFM), scanning electron microscopy (SEM) and X-ray diffraction (XRD). The corrosion resistance of the coatings in saliva solution at 37 °C was evaluated by potentiodynamic polarization. Additionally, the human osteosarcoma cell line (MG-63) was used to test the biocompatibility of the coatings. The results showed that all of the coatings grown uniformly and that the increasing substrate temperature induced an increase in their crystallinity. Corrosion performance of the coatings was improved with the increase of the substrate temperature from 400 °C to 800 °C. Furthermore, all the coatings support the attachment and growth of the osteosarcoma cells with regard to the in vitro test findings.

Essential Role of Chromatin Remodeling Protein Bptf in Early Mouse Embryos and Embryonic Stem Cells

PubMed Central

Landry, Joseph; Sharov, Alexei A.; Piao, Yulan; Sharova, Lioudmila V.; Xiao, Hua; Southon, Eileen; Matta, Jennifer; Tessarollo, Lino; Zhang, Ying E.; Ko, Minoru S. H.; Kuehn, Michael R.; Yamaguchi, Terry P.; Wu, Carl

2008-01-01

We have characterized the biological functions of the chromatin remodeling protein Bptf (Bromodomain PHD-finger Transcription Factor), the largest subunit of NURF (Nucleosome Remodeling Factor) in a mammal. Bptf mutants manifest growth defects at the post-implantation stage and are reabsorbed by E8.5. Histological analyses of lineage markers show that Bptf−/− embryos implant but fail to establish a functional distal visceral endoderm. Microarray analysis at early stages of differentiation has identified Bptf-dependent gene targets including homeobox transcriptions factors and genes essential for the development of ectoderm, mesoderm, and both definitive and visceral endoderm. Differentiation of Bptf−/− embryonic stem cell lines into embryoid bodies revealed its requirement for development of mesoderm, endoderm, and ectoderm tissue lineages, and uncovered many genes whose activation or repression are Bptf-dependent. We also provide functional and physical links between the Bptf-containing NURF complex and the Smad transcription factors. These results suggest that Bptf may co-regulate some gene targets of this pathway, which is essential for establishment of the visceral endoderm. We conclude that Bptf likely regulates genes and signaling pathways essential for the development of key tissues of the early mouse embryo. PMID:18974875

Restoration of neurological functions by neuroprosthetic technologies: future prospects and trends towards micro-, nano-, and biohybrid systems.

PubMed

Stieglitz, T

2007-01-01

Today applications of neural prostheses that successfully help patients to increase their activities of daily living and participate in social life again are quite simple implants that yield definite tissue response and are well recognized as foreign body. Latest developments in genetic engineering, nanotechnologies and materials sciences have paved the way to new scenarios towards highly complex systems to interface the human nervous system. Combinations of neural cells with microimplants promise stable biohybrid interfaces. Nanotechnology opens the door to macromolecular landscapes on implants that mimic the biologic topology and surface interaction of biologic cells. Computer sciences dream of technical cognitive systems that act and react due to knowledge-based conclusion mechanisms to a changing or adaptive environment. Different sciences start to interact and discuss the synergies when methods and paradigms from biology, computer sciences and engineering, neurosciences, psychology will be combined. They envision the era of "converging technologies" to completely change the understanding of science and postulate a new vision of humans. In this chapter, these research lines will be discussed on some examples as well as the societal implications and ethical questions that arise from these new opportunities.

Hydroxyapatite grafted carbon nanotubes and graphene nanosheets: promising bone implant materials.

PubMed

Oyefusi, Adebola; Olanipekun, Opeyemi; Neelgund, Gururaj M; Peterson, Deforest; Stone, Julia M; Williams, Ebonee; Carson, Laura; Regisford, Gloria; Oki, Aderemi

2014-11-11

In the present study, hydroxyapatite (HA) was successfully grafted to carboxylated carbon nanotubes (CNTs) and graphene nanosheets. The HA grafted CNTs and HA-graphene nanosheets were characterized using FT-IR, TGA, SEM and X-ray diffraction. The HA grafted CNTs and graphene nanosheets (CNTs-HA and Gr-HA) were further used to examine the proliferation and differentiation rate of temperature-sensitive human fetal osteoblastic cell line (hFOB 1.19). Total protein assays and western blot analysis of osteocalcin expression were used as indicators of cell proliferation and differentiation. Results indicated that hFOB 1.19 cells proliferate and differentiate well in treatment media containing CNTs-HA and graphene-HA. Both CNTs-HA and graphene-HA could be promising nanomaterials for use as scaffolds in bone tissue engineering. Copyright © 2014 Elsevier B.V. All rights reserved.

Esrrb-Cre Excises loxP-Flanked Alleles in Early Four-Cell Embryos

PubMed Central

Kim, Suyeon; Shaffer, Benjamin; Simerly, Calvin R.; Richard Chaillet, J.; Barak, Yaacov

2015-01-01

Among transgenic mice with ubiquitous Cre recombinase activity, all strains to date excise loxP-flanked (floxed) alleles, either at or before the zygote stage or at nondescript stages of development. This manuscript describes a new mouse strain, in which Cre recombinase, integrated into the Esrrb locus, efficiently excises floxed alleles in pre-implantation embryos at the onset of the four-cell stage. By enabling inactivation of genes only after the embryo has undergone two cleavages, this strain should facilitate in vivo studies of genes with essential gametic or zygotic functions. In addition, this study describes a new, highly pluripotent hybrid C57BL/6J × 129S1/SvImJ mouse embryonic stem cell line, HYB12, in which this knock-in and additional targeted alleles have been generated. PMID:26663459

Biomechanical Evaluation of Ti-Nb-Sn Alloy Implants with a Low Young’s Modulus

PubMed Central

Takahashi, Kenta; Shiraishi, Naru; Ishiko-Uzuka, Risa; Anada, Takahisa; Suzuki, Osamu; Masumoto, Hiroshi; Sasaki, Keiichi

2015-01-01

Dental implants are widely used and are a predictable treatment in various edentulous cases. Occlusal overload may be causally related to implant bone loss and a loss of integration. Stress concentrations may be diminished using a mechanobiologically integrated implant with bone tissue. The purpose of this study was to investigate the biomechanical behavior, biocompatibility and bioactivity of a Ti-Nb-Sn alloy as a dental implant material. It was compared with cpTi. Cell proliferation and alkaline phosphatase (ALP) activity were quantified. To assess the degree of osseointegration, a push-in test was carried out. Cell proliferation and ALP activity in the cells grown on prepared surfaces were similar for the Ti-Nb-Sn alloy and for cpTi in all the experiments. A comparison between the Ti-Nb-Sn alloy implant and the cpTi implant revealed that no significant difference was apparent for the push-in test values. These results suggest that implants fabricated using Ti-Nb-Sn have a similar biological potential as cpTi and are capable of excellent osseointegration. PMID:25775158

Microgravity

NASA Image and Video Library

2004-04-15

Biomedical research offers hope for a variety of medical problems, from diabetes to the replacement of damaged bone and tissues. Bioreactors, which are used to grow cells and tissue cultures, play a major role in such research and production efforts. Cell culturing, such as this bone cell culture, is an important part of biomedical research. The BioDyn payload includes a tissue engineering investigation. The commercial affiliate, Millenium Biologix, Inc., has been conducting bone implant experiments to better understand how synthetic bone can be used to treat bone-related illnesses and bone damaged in accidents. On STS-95, the BioDyn payload will include a bone cell culture aimed to help develop this commercial synthetic bone product. Millenium Biologix, Inc., is exploring the potential for making human bone implantable materials by seeding its proprietary artificial scaffold material with human bone cells. The product of this tissue engineering experiment using the Bioprocessing Modules (BPMs) on STS-95 is space-grown bone implants, which could have potential for dental implants, long bone grafts, and coating for orthopedic implants such as hip replacements.

Microgravity

NASA Image and Video Library

2004-04-15

Biomedical research offers hope for a variety of medical problems, from diabetes to the replacement of damaged bone and tissues. Bioreactors, which are used to grow cells and tissue cultures, play a major role in such research and production efforts. Cell culturing, such as this bone cell culture, is an important part of biomedical research. The BioDyn payload includes a tissue engineering investigation. The commercial affiliate, Millenium Biologix, Inc. has been conducting bone implant experiments to better understand how synthetic bone can be used to treat bone-related illnesses and bone damaged in accidents. On STS-95, the BioDyn payload will include a bone cell culture aimed to help develop this commercial synthetic bone product. Millenium Biologix, Inc. is exploring the potential for making human bone implantable materials by seeding its proprietary artificial scaffold material with human bone cells. The product of this tissue engineering experiment using the Bioprocessing Modules (BPMs) on STS-95 is space-grown bone implants, which could have potential for dental implants, long bone grafts, and coating for orthopedic implants such as hip replacements.

Characterization of Mesenchymal Stem Cell-Like Cells Derived From Human iPSCs via Neural Crest Development and Their Application for Osteochondral Repair

PubMed Central

Ikeya, Makoto; Yasui, Yukihiko; Ikeda, Yasutoshi; Ebina, Kosuke; Moriguchi, Yu; Shimomura, Kazunori; Hideki, Yoshikawa

2017-01-01

Mesenchymal stem cells (MSCs) derived from induced pluripotent stem cells (iPSCs) are a promising cell source for the repair of skeletal disorders. Recently, neural crest cells (NCCs) were reported to be effective for inducing mesenchymal progenitors, which have potential to differentiate into osteochondral lineages. Our aim was to investigate the feasibility of MSC-like cells originated from iPSCs via NCCs for osteochondral repair. Initially, MSC-like cells derived from iPSC-NCCs (iNCCs) were generated and characterized in vitro. These iNCC-derived MSC-like cells (iNCMSCs) exhibited a homogenous population and potential for osteochondral differentiation. No upregulation of pluripotent markers was detected during culture. Second, we implanted iNCMSC-derived tissue-engineered constructs into rat osteochondral defects without any preinduction for specific differentiation lineages. The implanted cells remained alive at the implanted site, whereas they failed to repair the defects, with only scarce development of osteochondral tissue in vivo. With regard to tumorigenesis, the implanted cells gradually disappeared and no malignant cells were detected throughout the 2-month follow-up. While this study did not show that iNCMSCs have efficacy for repair of osteochondral defects when implanted under undifferentiated conditions, iNCMSCs exhibited good chondrogenic potential in vitro under appropriate conditions. With further optimization, iNCMSCs may be a new source for tissue engineering of cartilage. PMID:28607560

Encapsulated Optically Responsive Cell Systems: Toward Smart Implants in Biomedicine.

PubMed

Boss, Christophe; Bouche, Nicolas; De Marchi, Umberto

2018-04-01

Managing increasingly prevalent chronic diseases will require close continuous monitoring of patients. Cell-based biosensors may be used for implantable diagnostic systems to monitor health status. Cells are indeed natural sensors in the body. Functional cellular systems can be maintained in the body for long-term implantation using cell encapsulation technology. By taking advantage of recent progress in miniaturized optoelectronic systems, the genetic engineering of optically responsive cells may be combined with cell encapsulation to generate smart implantable cell-based sensing systems. In biomedical research, cell-based biosensors may be used to study cell signaling, therapeutic effects, and dosing of bioactive molecules in preclinical models. Today, a wide variety of genetically encoded fluorescent sensors have been developed for real-time imaging of living cells. Here, recent developments in genetically encoded sensors, cell encapsulation, and ultrasmall optical systems are highlighted. The integration of these components in a new generation of biosensors is creating innovative smart in vivo cell-based systems, bringing novel perspectives for biomedical research and ultimately allowing unique health monitoring applications. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Magnetic resonance imaging of breast implants.

PubMed

Shah, Mala; Tanna, Neil; Margolies, Laurie

2014-12-01

Silicone breast implants have significantly evolved since their introduction half a century ago, yet implant rupture remains a common and expected complication, especially in patients with earlier-generation implants. Magnetic resonance imaging is the primary modality for assessing the integrity of silicone implants and has excellent sensitivity and specificity, and the Food and Drug Administration currently recommends periodic magnetic resonance imaging screening for silent silicone breast implant rupture. Familiarity with the types of silicone implants and potential complications is essential for the radiologist. Signs of intracapsular rupture include the noose, droplet, subcapsular line, and linguine signs. Signs of extracapsular rupture include herniation of silicone with a capsular defect and extruded silicone material. Specific sequences including water and silicone suppression are essential for distinguishing rupture from other pathologies and artifacts. Magnetic resonance imaging provides valuable information about the integrity of silicone implants and associated complications.

The influence of direct laser metal sintering implants on the early stages of osseointegration in diabetic mini-pigs

PubMed Central

Tan, Naiwen; Liu, Xiangwei; Cai, Yanhui; Zhang, Sijia; Jian, Bo; Zhou, Yuchao; Xu, Xiaoru; Ren, Shuai; Wei, Hongbo; Song, Yingliang

2017-01-01

Background High failure rates of oral implants have been reported in diabetic patients due to the disruption of osseointegration. The aim of this study was to investigate whether direct laser metal sintering (DLMS) could improve osseointegration in diabetic animal models. Methods Surface characterizations were carried out on two types of implants. Cell morphology and the osteogenic-related gene expression of MG63 cells were observed under conditions of DLMS and microarc oxidation (MAO). A diabetes model in mini-pigs was established by intravenous injection of streptozotocin (150 mg/kg), and a total of 36 implants were inserted into the mandibular region. Micro-computed tomography (micro-CT) and histologic evaluations were performed 3 and 6 months after implantation. Results The Ra (the average of the absolute height of all points) of MAO surface was 2.3±0.3 µm while the DLMS surface showed the Ra of 27.4±1.1 µm. The cells on DLMS implants spread out more podia than those on MAO implants through cell morphology analysis. Osteogenic-related gene expression was also dramatically increased in the DLMS group. Obvious improvement was observed in the micro-CT and Van Gieson staining analyses of DLMS implants compared with MAO at 3 months, although this difference disappeared by 6 months. DLMS implants showed a higher bone–implant contact percentage (33.2%±11.2%) at 3 months compared with MAO group (18.9%±7.3%) while similar results were showed at 6 months between DLMS group (42.8%±10.1%) and MAO group (38.3%±10.8%). Conclusion The three-dimensional environment of implant surfaces with highly porous and fully interconnected channel and pore architectures can improve cell spreading and accelerate the progress of osseointegration in diabetic mini-pigs. PMID:28814861

Gingival Retraction Methods for Fabrication of Fixed Partial Denture: Literature Review

PubMed Central

S, Safari; Ma, Vossoghi Sheshkalani; Mi, Vossoghi Sheshkalani; F, Hoseini Ghavam; M, Hamedi

2016-01-01

Fixed dental prosthesis success requires appropriate impression taking of the prepared finish line. This is critical in either tooth supported fixed prosthesis (crown and bridge) or implant supported fixed prosthesis (solid abutment). If the prepared finish line is adjacent to the gingival sulcus, gingival retraction techniques should be used to decrease the marginal discrepancy among the restoration and the prepared abutment. Accurate marginal positioning of the restoration in the prepared finish line of the abutment is required for therapeutic, preventive and aesthetic purposes. In this article, conventional and modern methods of gingival retraction in the fixed tooth supported prosthesis and fixed implant supported prosthesis are expressed. PubMed and Google Scholar databases were searched manually for studies on gingival tissue managements prior to impression making in fixed dental prosthesis since 1975. Conclusions were extracted and summarized. Keywords were impression making, gingival retraction, cordless retraction, and implant. Gingival retraction techniques can be classified as mechanical, chemical or surgical. In this article, different gingival management techniques are discussed. PMID:28959744

Gingival Retraction Methods for Fabrication of Fixed Partial Denture: Literature Review.

PubMed

S, Safari; Ma, Vossoghi Sheshkalani; Mi, Vossoghi Sheshkalani; F, Hoseini Ghavam; M, Hamedi

2016-06-01

Fixed dental prosthesis success requires appropriate impression taking of the prepared finish line. This is critical in either tooth supported fixed prosthesis (crown and bridge) or implant supported fixed prosthesis (solid abutment). If the prepared finish line is adjacent to the gingival sulcus, gingival retraction techniques should be used to decrease the marginal discrepancy among the restoration and the prepared abutment. Accurate marginal positioning of the restoration in the prepared finish line of the abutment is required for therapeutic, preventive and aesthetic purposes. In this article, conventional and modern methods of gingival retraction in the fixed tooth supported prosthesis and fixed implant supported prosthesis are expressed. PubMed and Google Scholar databases were searched manually for studies on gingival tissue managements prior to impression making in fixed dental prosthesis since 1975. Conclusions were extracted and summarized. Keywords were impression making, gingival retraction, cordless retraction, and implant. Gingival retraction techniques can be classified as mechanical, chemical or surgical. In this article, different gingival management techniques are discussed.

Cell Culturing of Cytoskeleton

NASA Technical Reports Server (NTRS)

2004-01-01

Biomedical research offers hope for a variety of medical problems, from diabetes to the replacement of damaged bone and tissues. Bioreactors, which are used to grow cells and tissue cultures, play a major role in such research and production efforts. Cell culturing, such as this bone cell culture, is an important part of biomedical research. The BioDyn payload includes a tissue engineering investigation. The commercial affiliate, Millenium Biologix, Inc., has been conducting bone implant experiments to better understand how synthetic bone can be used to treat bone-related illnesses and bone damaged in accidents. On STS-95, the BioDyn payload will include a bone cell culture aimed to help develop this commercial synthetic bone product. Millenium Biologix, Inc., is exploring the potential for making human bone implantable materials by seeding its proprietary artificial scaffold material with human bone cells. The product of this tissue engineering experiment using the Bioprocessing Modules (BPMs) on STS-95 is space-grown bone implants, which could have potential for dental implants, long bone grafts, and coating for orthopedic implants such as hip replacements.

Cell Culturing of Cytoskeleton

NASA Technical Reports Server (NTRS)

2004-01-01

Biomedical research offers hope for a variety of medical problems, from diabetes to the replacement of damaged bone and tissues. Bioreactors, which are used to grow cells and tissue cultures, play a major role in such research and production efforts. Cell culturing, such as this bone cell culture, is an important part of biomedical research. The BioDyn payload includes a tissue engineering investigation. The commercial affiliate, Millenium Biologix, Inc. has been conducting bone implant experiments to better understand how synthetic bone can be used to treat bone-related illnesses and bone damaged in accidents. On STS-95, the BioDyn payload will include a bone cell culture aimed to help develop this commercial synthetic bone product. Millenium Biologix, Inc. is exploring the potential for making human bone implantable materials by seeding its proprietary artificial scaffold material with human bone cells. The product of this tissue engineering experiment using the Bioprocessing Modules (BPMs) on STS-95 is space-grown bone implants, which could have potential for dental implants, long bone grafts, and coating for orthopedic implants such as hip replacements.

Monitoring the osseointegration process in porous Ti6Al4V implants produced by additive manufacturing: an experimental study in sheep.

PubMed

Kayacan, Mehmet C; Baykal, Yakup B; Karaaslan, Tamer; Özsoy, Koray; Alaca, İlker; Duman, Burhan; Delikanlı, Yunus E

2018-04-01

This study investigated the design and osseointegration process of transitive porous implants that can be used in humans and all trabecular and compact bone structure animals. The aim was to find a way of forming a strong and durable tissue bond on the bone-implant interface. Massive and transitive porous implants were produced on a direct metal laser sintering machine, surgically implanted into the skulls of sheep and kept in place for 12 weeks. At the end of the 12-week period, the Massive and porous implants removed from the sheep were investigated by scanning electron microscopy (SEM) to monitor the osseointegration process. In the literature, each study has selected standard sizes for pore diameter in the structures they use. However, none of these involved transitional porous structures. In this study, as opposed to standard pores, there were spherical or elliptical pores at the micro level, development channels and an inner region. Bone cells developed in the inner region. Transitive pores grown gradually in accordance with the natural structure of the bone were modeled in the inner region for cells to develop. Due to this structure, a strong and durable tissue bond could be formed at the bone-implant interface. Osseointegration processes of Massive vs. porous implants were compared. It was observed that cells were concentrated on the surface of Massive implants. Therefore, osseointegration between implant and bone was less than that of porous implants. In transitive porous implants, as opposed to Massive implants, an outer region was formed in the bone-implant interface that allowed tissue development.

Energy harvesting by implantable abiotically catalyzed glucose fuel cells

NASA Astrophysics Data System (ADS)

Kerzenmacher, S.; Ducrée, J.; Zengerle, R.; von Stetten, F.

Implantable glucose fuel cells are a promising approach to realize an autonomous energy supply for medical implants that solely relies on the electrochemical reaction of oxygen and glucose. Key advantage over conventional batteries is the abundant availability of both reactants in body fluids, rendering the need for regular replacement or external recharging mechanisms obsolete. Implantable glucose fuel cells, based on abiotic catalysts such as noble metals and activated carbon, have already been developed as power supply for cardiac pacemakers in the late-1960s. Whereas, in vitro and preliminary in vivo studies demonstrated their long-term stability, the performance of these fuel cells is limited to the μW-range. Consequently, no further developments have been reported since high-capacity lithium iodine batteries for cardiac pacemakers became available in the mid-1970s. In recent years research has been focused on enzymatically catalyzed glucose fuel cells. They offer higher power densities than their abiotically catalyzed counterparts, but the limited enzyme stability impedes long-term application. In this context, the trend towards increasingly energy-efficient low power MEMS (micro-electro-mechanical systems) implants has revived the interest in abiotic catalysts as a long-term stable alternative. This review covers the state-of-the-art in implantable abiotically catalyzed glucose fuel cells and their development since the 1960s. Different embodiment concepts are presented and the historical achievements of academic and industrial research groups are critically reviewed. Special regard is given to the applicability of the concept as sustainable micro-power generator for implantable devices.

Terpinen-4-ol inhibits colorectal cancer growth via reactive oxygen species

PubMed Central

Nakayama, Ken; Murata, Soichiro; Ito, Hiromu; Iwasaki, Kenichi; Villareal, Myra Orlina; Zheng, Yun-Wen; Matsui, Hirofumi; Isoda, Hiroko; Ohkohchi, Nobuhiro

2017-01-01

Terpinen-4-ol (TP4O) is the main component of the essential oil extracted from Melaleuca alternifolia, known as the tea tree, of the botanical family Myrtaceae. The anticancer effects of TP4O have been reported in several cancer cell lines. Previous reports have demonstrated that TP4O exerts anticancer effects by inducing apoptotic cell death in several cell lines; however, the underlying molecular mechanisms of these effects remain unclear. In the present study, the anticancer effects of TP4O against the colorectal cancer (CRC) cell lines HCT116 and RKO were evaluated using WST-8 and bromodeoxyuridine assays. The mechanism of cell death was investigated by the measurement of caspase-3/7, Annexin V and lactate dehydrogenase release. Reactive oxygen species (ROS) levels induced by TP4O were evaluated by electron spin resonance and quantitative measurement of dihydroethidium. Localization of the ROS derived from mitochondria was observed by confocal inverted microscopy. Protein levels of ROS scavengers were assessed by western blotting analysis. To confirm the role of ROS, cell viability was measured in the presence of antioxidant reagents. In an in vivo xenograft model of ICR-SCID mice implanted with HCT116 cells, 200 mg/kg TP4O was injected locally, and tumor growth was compared with that of the control. TP4O induced apoptotic cell death in HCT116 and RKO cells in a dose-dependent manner, and TP4O also increased the levels of ROS generated by mitochondria. TP4O-induced cell death was rescued by administration of antioxidant regents. In vivo, TP4O inhibited the proliferation of HCT116 xenografts compared with that of the control group. The results of the present study suggest that TP4O induces apoptosis in CRC cells through ROS generation. Furthermore, TP4O is potentially useful for the development of novel therapies against CRC. PMID:28781645

Bone marrow derived stem cells in joint and bone diseases: a concise review.

PubMed

Marmotti, Antonio; de Girolamo, Laura; Bonasia, Davide Edoardo; Bruzzone, Matteo; Mattia, Silvia; Rossi, Roberto; Montaruli, Angela; Dettoni, Federico; Castoldi, Filippo; Peretti, Giuseppe

2014-09-01

Stem cells have huge applications in the field of tissue engineering and regenerative medicine. Their use is currently not restricted to the life-threatening diseases but also extended to disorders involving the structural tissues, which may not jeopardize the patients' life, but certainly influence their quality of life. In fact, a particularly popular line of research is represented by the regeneration of bone and cartilage tissues to treat various orthopaedic disorders. Most of these pioneering research lines that aim to create new treatments for diseases that currently have limited therapies are still in the bench of the researchers. However, in recent years, several clinical trials have been started with satisfactory and encouraging results. This article aims to review the concept of stem cells and their characterization in terms of site of residence, differentiation potential and therapeutic prospective. In fact, while only the bone marrow was initially considered as a "reservoir" of this cell population, later, adipose tissue and muscle tissue have provided a considerable amount of cells available for multiple differentiation. In reality, recently, the so-called "stem cell niche" was identified as the perivascular space, recognizing these cells as almost ubiquitous. In the field of bone and joint diseases, their potential to differentiate into multiple cell lines makes their application ideally immediate through three main modalities: (1) cells selected by withdrawal from bone marrow, subsequent culture in the laboratory, and ultimately transplant at the site of injury; (2) bone marrow aspirate, concentrated and directly implanted into the injury site; (3) systemic mobilization of stem cells and other bone marrow precursors by the use of growth factors. The use of this cell population in joint and bone disease will be addressed and discussed, analysing both the clinical outcomes but also the basic research background, which has justified their use for the treatment of bone, cartilage and meniscus tissues.

Bag-1 and Bcl-2 gene transfer in malignant glioma: modulation of cell cycle regulation and apoptosis.

PubMed

Roth, W; Grimmel, C; Rieger, L; Strik, H; Takayama, S; Krajewski, S; Meyermann, R; Dichgans, J; Reed, J C; Weller, M

2000-04-01

Bag-1 is a heat shock 70 kDa (Hsp70)-binding protein that can collaborate with Bcl-2 in suppressing apoptosis under some conditions. Here, we report that 11 of 12 human glioma cell lines express Bag-1 protein in vitro. Moreover, 15 of 19 human glioblastomas expressed Bag-1 as assessed by immunohistochemistry in primary tumor specimens. To examine the biological effects of Bag-1 in glioma cells, we expressed Bag-1 or Bcl-2 transgenes in 2 human malignant glioma cell lines, LN-18 and LN-229. Bag-1 significantly slowed glioma cell growth and reduced clonogenicity of both cell lines in vitro. Coexpressed Bcl-2 abrogated these effects of Bag-1. Intracranial LN-229 glioma xenografts implanted into nude mice revealed a substantial growth advantage afforded by Bcl-2. Bag-1 had no such effect, either in the absence or presence of Bcl-2. Upon serum starvation in vitro, Bcl-2 prevented cell death whereas Bag-1 did not. Both Bcl-2 and Bag-1 slowed proliferation of serum-starved cells when expressed alone. Importantly, coexpression of Bcl-2 and Bag-1 provided a distinct growth advantage under conditions of serum starvation that is probably the result of (i) the death-preventing activity of Bcl-2 and (ii) the property of Bag-1 to overcome a Bcl-2-mediated enhancement of exit from the cell cycle. In contrast to these Bcl-2/Bag-1 interactions observed under serum starvation conditions, Bag-1 did not further enhance the strong protection from staurosporine-, CD95 (Fas/Apo1) ligand-, Apo2 ligand (TRAIL)- or chemotherapeutic drug-induced apoptosis afforded by Bcl-2. Taken together, these results indicate a role for Bag-1/Bcl-2 interactions in providing a survival advantage to cancer cells in a deprived microenvironment that may be characteristic of ischemic/hypoxic tumors such as human glioblastoma multiforme, and suggest that Bcl-2/Bag-1 interactions also modulate cell proliferation.

Investigation of gastric cancers in nude mice using X-ray in-line phase contrast imaging

PubMed Central

2014-01-01

Background This paper is to report the new imaging of gastric cancers without the use of imaging agents. Both gastric normal regions and gastric cancer regions can be distinguished by using the principal component analysis (PCA) based on the gray level co-occurrence matrix (GLCM). Methods Human gastric cancer BGC823 cells were implanted into the stomachs of nude mice. Then, 3, 5, 7, 9 or 11 days after cancer cells implantation, the nude mice were sacrificed and their stomachs were removed. X-ray in-line phase contrast imaging (XILPCI), an X-ray phase contrast imaging method, has greater soft tissue contrast than traditional absorption radiography and generates higher-resolution images. The gastric specimens were imaged by an XILPCIs’ charge coupled device (CCD) of 9 μm image resolution. The PCA of the projective images’ region of interests (ROIs) based on GLCM were extracted to discriminate gastric normal regions and gastric cancer regions. Different stages of gastric cancers were classified by using support vector machines (SVMs). Results The X-ray in-line phase contrast images of nude mice gastric specimens clearly show the gastric architectures and the details of the early gastric cancers. The phase contrast computed tomography (CT) images of nude mice gastric cancer specimens are better than the traditional absorption CT images without the use of imaging agents. The results of the PCA of the texture parameters based on GLCM of normal regions is (F1 + F2) > 8.5, but those of cancer regions is (F1 + F2) < 8.5. The classification accuracy is 83.3% that classifying gastric specimens into different stages using SVMs. Conclusions This is a very preliminary feasibility study. With further researches, XILPCI could become a noninvasive method for future the early detection of gastric cancers or medical researches. PMID:25060352

In Vitro Analysis of Cartilage Regeneration Using a Collagen Type I Hydrogel (CaReS) in the Bovine Cartilage Punch Model.

PubMed

Horbert, Victoria; Xin, Long; Foehr, Peter; Brinkmann, Olaf; Bungartz, Matthias; Burgkart, Rainer H; Graeve, T; Kinne, Raimund W

2018-02-01

Objective Limitations of matrix-assisted autologous chondrocyte implantation to regenerate functional hyaline cartilage demand a better understanding of the underlying cellular/molecular processes. Thus, the regenerative capacity of a clinically approved hydrogel collagen type I implant was tested in a standardized bovine cartilage punch model. Methods Cartilage rings (outer diameter 6 mm; inner defect diameter 2 mm) were prepared from the bovine trochlear groove. Collagen implants (± bovine chondrocytes) were placed inside the cartilage rings and cultured up to 12 weeks. Cartilage-implant constructs were analyzed by histology (hematoxylin/eosin; safranin O), immunohistology (aggrecan, collagens 1 and 2), and for protein content, RNA expression, and implant push-out force. Results Cartilage-implant constructs revealed vital morphology, preserved matrix integrity throughout culture, progressive, but slight proteoglycan loss from the "host" cartilage or its surface and decreasing proteoglycan release into the culture supernatant. In contrast, collagen 2 and 1 content of cartilage and cartilage-implant interface was approximately constant over time. Cell-free and cell-loaded implants showed (1) cell migration onto/into the implant, (2) progressive deposition of aggrecan and constant levels of collagens 1 and 2, (3) progressively increased mRNA levels for aggrecan and collagen 2, and (4) significantly augmented push-out forces over time. Cell-loaded implants displayed a significantly earlier and more long-lasting deposition of aggrecan, as well as tendentially higher push-out forces. Conclusion Preserved tissue integrity and progressively increasing cartilage differentiation and push-out forces for up to 12 weeks of cultivation suggest initial cartilage regeneration and lateral bonding of the implant in this in vitro model for cartilage replacement materials.

Metallic ion content and damage to the DNA in oral mucosa cells patients treated dental implants.

PubMed

López-Jornet, Pía; Perrez, Francisco Parra; Calvo-Guirado, José Luis; Ros-Llor, Irene; LLor-Ros, Irene; Ramírez-Fernández, Piedad

2014-07-01

The aim of this study was to assess the potential genotoxicity of dental implants, evaluating biomarkers of DNA damage (micronuclei and/or nuclear buds), cytokinetic defects (binucleated cells) and the presence of trace metals in gingival cells of patients with implants, comparing these with a control group. A total of 60 healthy adults (30 patients with dental implants and 30 control patients without) were included in the study. Medical and dental histories were made for each including life-style factors. Genotoxicity effects were assessed by micronucleus assays in the gingival epithelial cells of each patient; 1,000 epithelial cells were analyzed, evaluating the frequency of micronucleated cells and other nuclear anomalies. The concentration of metals (Al(27), Ag(107), Co (59), Cr (52), Cu(63), Fe(56), Sn(118), Mn(55), Mo(92), Ni(60), Pb(208), Ti(47)) were assayed by means of coupled plasma-mass spectrophotometry (ICP-MS). The frequency of micronuclei in the patient group with implants was higher than in the control group but without statistically significant differences (P > 0.05). Similar results were found for binucleated cells and nuclear buds (P > 0.05). For metals assayed by ICP-MS, significant differences were found for Ti(47) (P ≤ 0.045). Univariate analysis identified a significant association between the presence of micronuclei and age. Dental implants do not induce DNA damage in gingival cells, the slight effects observed cannot be indicated as biologically relevant.

Physiological joint line total knee arthroplasty designs are especially sensitive to rotational placement - A finite element analysis.

PubMed

Moewis, Philippe; Checa, Sara; Kutzner, Ines; Hommel, Hagen; Duda, Georg N

2018-01-01

Mechanical and kinematical aligning techniques are the usual positioning methods during total knee arthroplasty. However, alteration of the physiological joint line and unbalanced medio-lateral load distribution are considered disadvantages in the mechanical and kinematical techniques, respectively. The aim of this study was to analyse the influence of the joint line on the strain and stress distributions in an implanted knee and their sensitivity to rotational mal-alignment. Finite element calculations were conducted to analyse the stresses in the PE-Inlay and the mechanical strains at the bone side of the tibia component-tibia bone interface during normal positioning of the components and internal and external mal-rotation of the tibial component. Two designs were included, a horizontal and a physiological implant. The loading conditions are based on internal knee joint loads during walking. A medialization of the stresses on the PE-Inlay was observed in the physiological implant in a normal position, accompanied by higher stresses in the mal-rotated positions. Within the tibia component-tibia bone interface, similar strain distributions were observed in both implant geometries in the normal position. However, a medialization of the strains was observed in the physiological implant in both mal-rotated conditions with greater bone volume affected by higher strains. Although evident changes due to mal-rotation were observed, the stresses do not suggest a local plastic deformation of the PE-Inlay. The strains values within most of the tibia component-tibia bone interface were in the physiological strain zone and no significant bone changes would be expected. The physiological cut on the articular aspect showed no detrimental effect compared to the horizontal implant.

Energy Harvesting by Subcutaneous Solar Cells: A Long-Term Study on Achievable Energy Output.

PubMed

Bereuter, L; Williner, S; Pianezzi, F; Bissig, B; Buecheler, S; Burger, J; Vogel, R; Zurbuchen, A; Haeberlin, A

2017-05-01

Active electronic implants are powered by primary batteries, which induces the necessity of implant replacement after battery depletion. This causes repeated interventions in a patients' life, which bears the risk of complications and is costly. By using energy harvesting devices to power the implant, device replacements may be avoided and the device size may be reduced dramatically. Recently, several groups presented prototypes of implants powered by subcutaneous solar cells. However, data about the expected real-life power output of subcutaneously implanted solar cells was lacking so far. In this study, we report the first real-life validation data of energy harvesting by subcutaneous solar cells. Portable light measurement devices that feature solar cells (cell area = 3.6 cm 2 ) and continuously measure a subcutaneous solar cell's output power were built. The measurement devices were worn by volunteers in their daily routine in summer, autumn and winter. In addition to the measured output power, influences such as season, weather and human activity were analyzed. The obtained mean power over the whole study period was 67 µW (=19 µW cm -2 ), which is sufficient to power e.g. a cardiac pacemaker.

Effect of phosphate treatment of Acid-etched implants on mineral apposition rates near implants in a dog model.

PubMed

Foley, Christine Hyon; Kerns, David G; Hallmon, William W; Rivera-Hidalgo, Francisco; Nelson, Carl J; Spears, Robert; Dechow, Paul C; Opperman, Lynne A

2010-01-01

This study evaluated the effects of phosphate coating of acid-etched titanium on the mineral apposition rate (MAR) and new bone-to-implant contact (BIC) in a canine model. Titanium implants (2.2 3 4 mm) with acid-etched surfaces that were electrolytically phosphated or not were placed in 48 mandibular sites in six foxhounds. Tetracycline and calcein dyes were administered 1 week after implant placement and 1 week before sacrifice. At 12 weeks after implant placement, the animals were sacrificed. MAR and BIC were evaluated using fluorescence microscopy. Light microscopic and histologic evaluations were performed on undecalcified sections. Microscopic evaluation showed the presence of healthy osteoblasts lining bone surfaces near implants. Similar BIC was observed in phosphated and nonphosphated titanium implant sites. MAR was significantly higher around the nonphosphated titanium implant surfaces than around the phosphated titanium samples. No significant differences were found between dogs or implant sites. Acid-etched implants showed significantly higher MARs compared to acid-etched, phosphate-coated implants. Int J Maxillofac Implants 2010;25:278-286.

Study of wettability and cell viability of H implanted stainless steel

NASA Astrophysics Data System (ADS)

Shafique, Muhammad Ahsan; Ahmad, Riaz; Rehman, Ihtesham Ur

2018-03-01

In the present work, the effect of hydrogen ion implantation on surface wettability and biocompatibility of stainless steel is investigated. Hydrogen ions are implanted in the near-surface of stainless steel to facilitate hydrogen bonding at different doses with constant energy of 500 KeV, which consequently improve the surface wettability. Treated and untreated sample are characterized for surface wettability, incubation of hydroxyapatite and cell viability. Contact angle (CA) study reveals that surface wettability increases with increasing H-ion dose. Raman spectroscopy shows that precipitation of hydroxyapatite over the surface increase with increasing dose of H-ions. Cell viability study using MTT assay describes improved cell viability in treated samples as compared to the untreated sample. It is found that low dose of H-ions is more effective for cell proliferation and the cell count decreases with increasing ion dose. Our study demonstrates that H ion implantation improves the surface wettability and biocompatibility of stainless steel.

Periodontal tissue regeneration by combined implantation of adipose tissue-derived stem cells and platelet-rich plasma in a canine model.

PubMed

Tobita, Morikuni; Uysal, Cagri A; Guo, Xin; Hyakusoku, Hiko; Mizuno, Hiroshi

2013-12-01

One goal of periodontal therapy is to regenerate periodontal tissues. Stem cells, growth factors and scaffolds and biomaterials are vital for the restoration of the architecture and function of complex tissues. Adipose tissue-derived stem cells (ASCs) are an ideal population of stem cells for practical regenerative medicine. In addition, platelet-rich plasma (PRP) can be useful for its ability to stimulate tissue regeneration. PRP contains various growth factors and may be useful as a cell carrier in stem cell therapies. The purpose of this study was to determine whether a mixture of ASCs and PRP promoted periodontal tissue regeneration in a canine model. Autologous ASCs and PRP were implanted into areas with periodontal tissue defects. Periodontal tissue defects that received PRP alone or non-implantation were also examined. Histologic, immunohistologic and x-ray studies were performed 1 or 2 months after implantation. The amount of newly formed bone and the scale of newly formed cementum in the region of the periodontal tissue defect were analyzed on tissue sections. The areas of newly formed bone and cementum were greater 2 months after implantation of ASCs and PRP than at 1 month after implantation, and the radiopacity in the region of the periodontal tissue defect increased markedly by 2 months after implantation. The ASCs and PRP group exhibited periodontal tissue with the correct architecture, including alveolar bone, cementum-like structures and periodontal ligament-like structures, by 2 months after implantation. These findings suggest that a combination of autologous ASCs and PRP promotes periodontal tissue regeneration that develops the appropriate architecture for this complex tissue. Copyright © 2013 International Society for Cellular Therapy. Published by Elsevier Inc. All rights reserved.

Sphene ceramics for orthopedic coating applications: an in vitro and in vivo study.

PubMed

Ramaswamy, Yogambha; Wu, Chengtie; Dunstan, Colin R; Hewson, Benjamin; Eindorf, Tanja; Anderson, Gail I; Zreiqat, Hala

2009-10-01

The host response to titanium alloy (Ti-6Al-4V) is not always favorable as a fibrous layer may form at the skeletal tissue-device interface, causing aseptic loosening. Recently, sphene (CaTiSiO(5)) ceramics were developed by incorporating Ti in the Ca-Si system, and found to exhibit improved chemical stability. The aim of this study is to evaluate the in vitro response of human osteoblast-like cells, human osteoclasts and human microvascular endothelial cells to sphene ceramics and determine whether coating Ti-6Al-4V implants with sphene enhances anchorage to surrounding bone. The study showed that sphene ceramics support human osteoblast-like cell attachment with organized cytoskeleton structure and express increased mRNA levels of osteoblast-related genes. Sphene ceramics were able to induce the differentiation of monocytes to form functional osteoclasts with the characteristic features of f-actin and alpha(v)beta(3) integrin, and express osteoclast-related genes. Human endothelial cells were also able to attach and express the endothelial cell markers ZO-1 and VE-Cadherin when cultured on sphene ceramics. Histological staining, enzyme histochemistry and immunolabelling were used for identification of mineralized bone and bone remodelling around the coated implants. Ti-6Al-4V implants coated with sphene showed new bone formation and filled the gap between the implants and existing bone in a manner comparable to that of the hydroxyapatite coatings used as control. The new bone was in direct contact with the implants, whereas fibrous tissue formed between the bone and implant with uncoated Ti-6Al-4V. The in vivo assessment of sphene-coated implants supports our in vitro observation and suggests that they have the ability to recruit osteogenic cells, and thus support bone formation around the implants and enhance osseointegration.

A living thick nanofibrous implant bifunctionalized with active growth factor and stem cells for bone regeneration.

PubMed

Eap, Sandy; Keller, Laetitia; Schiavi, Jessica; Huck, Olivier; Jacomine, Leandro; Fioretti, Florence; Gauthier, Christian; Sebastian, Victor; Schwinté, Pascale; Benkirane-Jessel, Nadia

2015-01-01

New-generation implants focus on robust, durable, and rapid tissue regeneration to shorten recovery times and decrease risks of postoperative complications for patients. Herein, we describe a new-generation thick nanofibrous implant functionalized with active containers of growth factors and stem cells for regenerative nanomedicine. A thick electrospun poly(ε-caprolactone) nanofibrous implant (from 700 μm to 1 cm thick) was functionalized with chitosan and bone morphogenetic protein BMP-7 as growth factor using layer-by-layer technology, producing fish scale-like chitosan/BMP-7 nanoreservoirs. This extracellular matrix-mimicking scaffold enabled in vitro colonization and bone regeneration by human primary osteoblasts, as shown by expression of osteocalcin, osteopontin, and bone sialoprotein (BSPII), 21 days after seeding. In vivo implantation in mouse calvaria defects showed significantly more newly mineralized extracellular matrix in the functionalized implant compared to a bare scaffold after 30 days' implantation, as shown by histological scanning electron microscopy/energy dispersive X-ray microscopy study and calcein injection. We have as well bifunctionalized our BMP-7 therapeutic implant by adding human mesenchymal stem cells (hMSCs). The activity of this BMP-7-functionalized implant was again further enhanced by the addition of hMSCs to the implant (living materials), in vivo, as demonstrated by the analysis of new bone formation and calcification after 30 days' implantation in mice with calvaria defects. Therefore, implants functionalized with BMP-7 nanocontainers associated with hMSCs can act as an accelerator of in vivo bone mineralization and regeneration.

Understanding rare adverse sequelae of breast implants: anaplastic large-cell lymphoma, late seromas, and double capsules

PubMed Central

Nava, Maurizio Bruno; Rocco, Nicola

2017-01-01

Breast implant-associated anaplastic large cell lymphoma (BI-ALCL) is a distinct type of T-cell lymphoma arising around breast implants. The United States FDA recently updated the 2011 safety communication, warning that women with breast implants may have a very low risk of developing ALCL adjacent to a breast implant. According to the World Health Organization, BI-LCL is not a breast cancer or cancer of the breast tissue; it is a lymphoma, a cancer of immune cells. BI-ALCL is highly curable in the majority of patients. Informed consent should include the risk of BI-ALCL with breast implant patients. Women with breast implants are encouraged to contact their plastic surgeon if they notice swelling, fluid collections, or unexpected changes in breast shape. Physicians are encouraged to send suspicious peri-prosthetic fluid for CD30 immunohistochemistry, cell block cytology, and culture in symptomatic patients. An observation from reported cases indicates a predominance of textured device involvement. More information is needed to fully understand risk factors and etiology. The association of bacteria and biofilm with ALCL is currently being investigated and one theory is that biofilm may play a role in this disease process stressing the importance of best practice techniques intraoperatively. Recent studies have reported clinical presentation, prognosis, and treatment outcomes with long term followup demonstrating the critical role for surgical management. PMID:28497021

Understanding rare adverse sequelae of breast implants: anaplastic large-cell lymphoma, late seromas, and double capsules.

PubMed

Clemens, Mark W; Nava, Maurizio Bruno; Rocco, Nicola; Miranda, Roberto N

2017-04-01

Breast implant-associated anaplastic large cell lymphoma (BI-ALCL) is a distinct type of T-cell lymphoma arising around breast implants. The United States FDA recently updated the 2011 safety communication, warning that women with breast implants may have a very low risk of developing ALCL adjacent to a breast implant. According to the World Health Organization, BI-LCL is not a breast cancer or cancer of the breast tissue; it is a lymphoma, a cancer of immune cells. BI-ALCL is highly curable in the majority of patients. Informed consent should include the risk of BI-ALCL with breast implant patients. Women with breast implants are encouraged to contact their plastic surgeon if they notice swelling, fluid collections, or unexpected changes in breast shape. Physicians are encouraged to send suspicious peri-prosthetic fluid for CD30 immunohistochemistry, cell block cytology, and culture in symptomatic patients. An observation from reported cases indicates a predominance of textured device involvement. More information is needed to fully understand risk factors and etiology. The association of bacteria and biofilm with ALCL is currently being investigated and one theory is that biofilm may play a role in this disease process stressing the importance of best practice techniques intraoperatively. Recent studies have reported clinical presentation, prognosis, and treatment outcomes with long term followup demonstrating the critical role for surgical management.

Optimized in vitro procedure for assessing the cytocompatibility of magnesium-based biomaterials.

PubMed

Jung, Ole; Smeets, Ralf; Porchetta, Dario; Kopp, Alexander; Ptock, Christoph; Müller, Ute; Heiland, Max; Schwade, Max; Behr, Björn; Kröger, Nadja; Kluwe, Lan; Hanken, Henning; Hartjen, Philip

2015-09-01

Magnesium (Mg) is a promising biomaterial for degradable implant applications that has been extensively studied in vitro and in vivo in recent years. In this study, we developed a procedure that allows an optimized and uniform in vitro assessment of the cytocompatibility of Mg-based materials while respecting the standard protocol DIN EN ISO 10993-5:2009. The mouse fibroblast line L-929 was chosen as the preferred assay cell line and MEM supplemented with 10% FCS, penicillin/streptomycin and 4mM l-glutamine as the favored assay medium. The procedure consists of (1) an indirect assessment of effects of soluble Mg corrosion products in material extracts and (2) a direct assessment of the surface compatibility in terms of cell attachment and cytotoxicity originating from active corrosion processes. The indirect assessment allows the quantification of cell-proliferation (BrdU-assay), viability (XTT-assay) as well as cytotoxicity (LDH-assay) of the mouse fibroblasts incubated with material extracts. Direct assessment visualizes cells attached to the test materials by means of live-dead staining. The colorimetric assays and the visual evaluation complement each other and the combination of both provides an optimized and simple procedure for assessing the cytocompatibility of Mg-based biomaterials in vitro. Copyright © 2015 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Induction of Osteogenic Differentiation of Adipose Derived Stem Cells by Microstructured Nitinol Actuator-Mediated Mechanical Stress

PubMed Central

Strauß, Sarah; Dudziak, Sonja; Hagemann, Ronny; Barcikowski, Stephan; Fliess, Malte; Israelowitz, Meir; Kracht, Dietmar; Kuhbier, Jörn W.; Radtke, Christine; Reimers, Kerstin; Vogt, Peter M.

2012-01-01

The development of large tissue engineered bone remains a challenge in vitro, therefore the use of hybrid-implants might offer a bridge between tissue engineering and dense metal or ceramic implants. Especially the combination of the pseudoelastic implant material Nitinol (NiTi) with adipose derived stem cells (ASCs) opens new opportunities, as ASCs are able to differentiate osteogenically and therefore enhance osseointegration of implants. Due to limited knowledge about the effects of NiTi-structures manufactured by selective laser melting (SLM) on ASCs the study started with an evaluation of cytocompatibility followed by the investigation of the use of SLM-generated 3-dimensional NiTi-structures preseeded with ASCs as osteoimplant model. In this study we could demonstrate for the first time that osteogenic differentiation of ASCs can be induced by implant-mediated mechanical stimulation without support of osteogenic cell culture media. By use of an innovative implant design and synthesis via SLM-technique we achieved high rates of vital cells, proper osteogenic differentiation and mechanically loadable NiTi-scaffolds could be achieved. PMID:23236461

[Port device central venous access in children with chronic renal disease--personal experience].

PubMed

Szczepańska, Maria; Szprynger, Krystyna; Stoksik, Piotr; Morawiec-Knysak, Aurelia; Adamczyk, Piotr; Ziora, Katarzyna; Oswiecimska, Joanna

2006-01-01

The application of central venous lines in children has been widely accepted in the case of pediatric cancer treatment. This is of particular importance when the treatment must be continued during the long period of time. The indication to long-term application of central venous lines became significantly frequent within last years. They are necessary in the treatment of chronic pediatric patients, in whom the central venous line allows continuous access for medication, parenteral rehydration, nutrition and frequent blood sampling. In the current study authors present their experience in subcutaneous port devices application in children with kidney disease. The case history data obtained from 8 children were retrospectively analysed. In these children subcutaneous port devices were applied for mean 26.7 months (totally 9 port devices). The mean age at the time of implantation was 2.2 years, and the mean body weight--10.6 kg. Peripheral venous access in all children was bad. In one child during the time of implantation the hematoma of coli and chest was present. Infectious complications connected with implanted port device were not detected. Thrombotic complications were present in 6 children with chronic renal failure--in 5 the lumen of port device has been successfully recanalysed, in 3 cases even several times. In 1 child the thrombus on the tip of central venous line was detected. In 2 children the removal of port device was necessary because of breakage of venous line and in the second case because of port device thrombosis. Two children died with functioning port device. The cause of death was not connected with implanted port device. The application of subcutaneous port devices definitely improved the comfort of treatment but was significantly associated with thrombotic complications. Infectious complications were not detected as compared to hematological group of patients.

[Study on anti-tumor effect of cyanidin-3-glucoside on ovarian cancer].

PubMed

Zeng, Linchai; Gao, Jie; Zhang, Rui

2012-06-01

To investigate the effect and the mechanism of cyanidin-3-glucoside (C3G) in the growth inhibition of ovarian cancer in vitro and in vivo. After human ovarian cancer cell line HO-8910PM was treated with C3G, cell growth was determined by the Cell Counting Kit-8 (CCK-8) assay and apoptosis was evaluated by flow cytometry analysis stained with Annexin V-FITC/PI. The protein expression in HO-8910PM cells was analyzed by Western blot assay. HO-8910PM cells were injected subcutaneously into nude mice to establish xenograft model. After 3 weeks of implantation, mice were randomized into 2 groups (n = 8): control group, feed with 0.2 mL double distilled water; C3G group, feed with C3G at a dose of 5 mg x kg(-1). All treatment lasted for two weeks, thrice per week. Eight weeks after implantation, tumor weight and inhibition rate were evaluated respectively after the mice were sacrificed. Immunohistochemistry was used to detect the positive expression of Ki-67 and Mucin-4 in the tumors. The proliferation of ovarian cancer cells was inhibited significantly by C3G with IC50 being 13.82 mg x L(-1). Apoptosis rate induced by C3G was markedly highter than that of control. The expression of Mucin4 was down-regulated in HO-8910PM cells after treatment of C3G. C3G inhibited the growth of ovarian xenograft tumors in nude mice. Furthermore, the positive expression of Ki-67 and Mucin-4 were both decreased in tumors after administration of C3G. C3G exerts anti-tumor activity in ovarian cancer both in vitro and in vivo, which may be related to down-regulation of Mucin-4 protein.

The anti-fibrotic agent pirfenidone synergizes with cisplatin in killing tumor cells and cancer-associated fibroblasts.

PubMed

Mediavilla-Varela, Melanie; Boateng, Kingsley; Noyes, David; Antonia, Scott J

2016-03-02

Anti-fibrotic drugs such as pirfenidone have been developed for the treatment of idiopathic pulmonary fibrosis. Because activated fibroblasts in inflammatory conditions have similar characteristics as cancer-associated fibroblasts (CAFs) and CAFs contribute actively to the malignant phenotype, we believe that anti-fibrotic drugs have the potential to be repurposed as anti-cancer drugs. The effects of pirfenidone alone and in combination with cisplatin on human patient-derived CAF cell lines and non-small cell lung cancer (NSCLC) cell lines were examined. The impact on cell death in vitro as well as tumor growth in a mouse model was determined. Annexin V/PI staining and Western blot analysis were used to characterize cell death. Synergy was assessed with the combination index method using Calcusyn software. Pirfenidone alone induced apoptotic cell death in lung CAFs at a high concentration (1.5 mg/mL). However, co-culture in vitro experiments and co-implantation in vivo experiments showed that the combination of low doses of cisplatin (10 μM) and low doses of pirfenidone (0.5 mg/mL), in both CAFs and tumors, lead to increased cell death and decreased tumor progression, respectively. Furthermore, the combination of cisplatin and pirfenidone in NSCLC cells (A549 and H157 cells) leads to increased apoptosis and synergistic cell death. Our studies reveal for the first time that the combination of cisplatin and pirfenidone is active in preclinical models of NSCLC and therefore may be a new therapeutic approach in this disease.

Histatin 1 Enhances Cell Adhesion to Titanium in an Implant Integration Model.

PubMed

van Dijk, I A; Beker, A F; Jellema, W; Nazmi, K; Wu, G; Wismeijer, D; Krawczyk, P M; Bolscher, J G M; Veerman, E C I; Stap, J

2017-04-01

Cellular adhesion is essential for successful integration of dental implants. Rapid soft tissue integration is important to create a seal around the implant and prevent infections, which commonly cause implant failure and can result in bone loss. In addition, soft tissue management is important to obtain good dental aesthetics. We previously demonstrated that the salivary peptide histatin 1 (Hst1) causes a more than 2-fold increase in the ability of human adherent cells to attach and spread on a glass surface. Cells treated with Hst1 attached more rapidly and firmly to the substrate and to each other. In the current study, we examine the potential application of Hst1 for promotion of dental implant integration. Our results show that Hst1 enhances the attachment and spreading of soft tissue cell types (oral epithelial cells and fibroblasts) to titanium (Ti) and hydroxyapatite (HAP), biomaterials that have found wide applications as implant material in dentistry and orthopedics. For improved visualization of cell adhesion to Ti, we developed a novel technique that uses sputtering to deposit a thin, transparent layer of Ti onto glass slides. This approach allows detailed, high-resolution analysis of cell adherence to Ti in real time. Furthermore, our results suggest that Hst1 has no negative effects on cell survival. Given its natural occurrence in the oral cavity, Hst1 could be an attractive agent for clinical application. Importantly, even though Hst1 is specific for saliva of humans and higher primates, it stimulated the attachment and spreading of canine cells, paving the way for preclinical studies in canine models.

Microparticles and blood cells induce procoagulant activity via phosphatidylserine exposure in NSTEMI patients following stent implantation.

PubMed

Wang, Lixiu; Bi, Yayan; Cao, Muhua; Ma, Ruishuang; Wu, Xiaoming; Zhang, Yan; Ding, Wenbo; Liu, Yan; Yu, Qian; Zhang, Yingqian; Jiang, Hua; Sun, Yingchun; Tong, Dongxia; Guo, Li; Dong, Zengxiang; Tian, Ye; Kou, Junjie; Shi, Jialan

2016-11-15

Relatively little is known about the role of phosphatidylserine (PS) in procoagulant activity (PCA) in patients with non-ST-elevated myocardial infarction (NSTEMI) after stent implantation. This study was designed to evaluate whether exposed PS on microparticles (MPs) and blood cells were involved in the hypercoagulable state in NSTEMI patients with stent implantation. NSTEMI patients (n=90) and healthy controls (n=20) were included in our study. PS exposure on MPs and blood cells was analyzed with flow cytometer and confocal microscope. PCA was evaluated by clotting time, purified coagulation complex assays and fibrin production assays. Baseline levels of MPs and PS + blood cells were significantly higher (P<0.001) in the patients than in controls. After stent implantation, a remarkable increase was observed in both MPs and PS + blood cells. Specifically, PS + MPs, PS + platelets and erythrocytes peaked at 18h following stent implantation, while PS + leukocytes peaked on day 2. In addition, circulating MPs (mostly derived from platelets, leukocytes, erythrocytes and endothelial cells) cooperating with PS + blood cells, contributed to markedly shortened coagulation time and markedly increased FXa/thrombin/fibrin (all P<0.01) generation in patient group. Moreover, blockade of exposed PS on MPs and cells with lactadherin inhibited PCA by approximately 70%. Our results suggest that PS + MPs and blood cells play a procoagulant role in NSTEMI patients following stent implantation. Blockade of PS could become a novel therapeutic modality for the prevention of thrombosis in these patients. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

In Vivo Bone Formation Within Engineered Hydroxyapatite Scaffolds in a Sheep Model.

PubMed

Lovati, A B; Lopa, S; Recordati, C; Talò, G; Turrisi, C; Bottagisio, M; Losa, M; Scanziani, E; Moretti, M

2016-08-01

Large bone defects still represent a major burden in orthopedics, requiring bone-graft implantation to promote the bone repair. Along with autografts that currently represent the gold standard for complicated fracture repair, the bone tissue engineering offers a promising alternative strategy combining bone-graft substitutes with osteoprogenitor cells able to support the bone tissue ingrowth within the implant. Hence, the optimization of cell loading and distribution within osteoconductive scaffolds is mandatory to support a successful bone formation within the scaffold pores. With this purpose, we engineered constructs by seeding and culturing autologous, osteodifferentiated bone marrow mesenchymal stem cells within hydroxyapatite (HA)-based grafts by means of a perfusion bioreactor to enhance the in vivo implant-bone osseointegration in an ovine model. Specifically, we compared the engineered constructs in two different anatomical bone sites, tibia, and femur, compared with cell-free or static cell-loaded scaffolds. After 2 and 4 months, the bone formation and the scaffold osseointegration were assessed by micro-CT and histological analyses. The results demonstrated the capability of the acellular HA-based grafts to determine an implant-bone osseointegration similar to that of statically or dynamically cultured grafts. Our study demonstrated that the tibia is characterized by a lower bone repair capability compared to femur, in which the contribution of transplanted cells is not crucial to enhance the bone-implant osseointegration. Indeed, only in tibia, the dynamic cell-loaded implants performed slightly better than the cell-free or static cell-loaded grafts, indicating that this is a valid approach to sustain the bone deposition and osseointegration in disadvantaged anatomical sites.

The effects of implant topography on osseointegration under estrogen deficiency induced osteoporotic conditions: Histomorphometric, transcriptional and ultrastructural analysis.

PubMed

Du, Zhibin; Xiao, Yin; Hashimi, Saeed; Hamlet, Stephen M; Ivanovski, Saso

2016-09-15

Compromised bone quality and/or healing in osteoporosis are recognised risk factors for impaired dental implant osseointegration. This study examined the effects of (1) experimentally induced osteoporosis on titanium implant osseointegration and (2) the effect of modified implant surface topography on osseointegration under osteoporosis-like conditions. Machined and micro-roughened surface implants were placed into the maxillary first molar root socket of 64 ovariectomised and sham-operated Sprague-Dawley rats. Subsequent histological and SEM observations showed tissue maturation on the micro-rough surfaced implants in ovariectomised animals as early as 3days post-implantation. The degree of osseointegration was also significantly higher around the micro-rough implants in ovariectomised animals after 14days of healing although by day 28, similar levels of osseointegration were found for all test groups. The micro-rough implants significantly increased the early (day 3) gene expression of alkaline phosphatase, osteocalcin, receptor activator of nuclear factor kappa-B ligand and dentin matrix protein 1 in implant adherent cells. By day 7, the expression of inflammatory genes decreased while the expression of the osteogenic markers increased further although there were few statistically significant differences between the micro-rough and machined surfaces. Osteocyte morphology was also affected by estrogen deficiency with the size of the cells being reduced in trabecular bone. In conclusion, estrogen deficiency induced osteoporotic conditions negatively influenced the early osseointegration of machined implants while micro-rough implants compensated for these deleterious effects by enhancing osteogenic cell differentiation on the implant surface. Lower bone density, poor bone quality and osseous microstructural changes are all features characteristic of osteoporosis that may impair the osseointegration of dental implants. Using a clinically relevant trabecular bone model in the rat maxilla, we demonstrated histologically that the negative effects of surgically-induced osteoporosis on osseointegration could be ameliorated by the biomaterial's surface topography. Furthermore, gene expression analysis suggests this may be a result of enhanced osteogenic cell differentiation on the implant surface. Copyright © 2016 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Reversible inhibition of lysine specific demethylase 1 is a novel anti-tumor strategy for poorly differentiated endometrial carcinoma.

PubMed

Theisen, Emily R; Gajiwala, Snehal; Bearss, Jared; Sorna, Venkataswamy; Sharma, Sunil; Janat-Amsbury, Margit

2014-10-09

Endometrial cancer is the most common gynecologic malignancy. Type II endometrial carcinoma is often poorly differentiated and patients diagnosed with Type II disease (~11%) are disproportionately represented in annual endometrial cancer deaths (48%). Recent genomic studies highlight mutations in chromatin regulators as drivers in Type II endometrial carcinoma tumorigenesis, suggesting the use of epigenetic targeted therapies could provide clinical benefit to these patients. We investigated the anti-tumor efficacy of the LSD1 inhibitor HCI2509 in two poorly differentiated Type II endometrial cancer cell lines AN3CA and KLE. The effects of HCI2509 on viability, proliferation, anchorage-independent growth, global histone methylation, LSD1 target gene induction, cell cycle, caspase activation and TUNEL were assayed. KLE cells were used in an orthotopic xenograft model to assess the anti-tumor activity of HCI2509. Both AN3CA and KLE cells were sensitive to HCI2509 treatment with IC50s near 500 nM for cell viability. Inhibition of LSD1 with HCI2509 caused decreased proliferation and anchorage independent growth in soft agar, elevated global histone methylation, and perturbed the cell cycle in both cell lines. These effects were largely dose-dependent. HCI2509 treatment also caused apoptotic cell death. Orthotopic implantation of KLE cells resulted in slow-growing and diffuse tumors throughout the abdomen. Tumor burden was distributed log-normally. Treatment with HCI2509 resulted 5/9 tumor regressions such that treatment and regressions were significantly associated (p=0.034). Our findings demonstrate the anti-cancer properties of the LSD1 inhibitor HCI2509 on poorly differentiated endometrial carcinoma cell lines, AN3CA and KLE. HCI2509 showed single-agent efficacy in orthotopic xenograft studies. Continued studies are needed to preclinically validate LSD1 inhibition as a therapeutic strategy for endometrial carcinoma.

Air powder abrasive treatment as an implant surface cleaning method: a literature review.

PubMed

Tastepe, Ceylin S; van Waas, Rien; Liu, Yuelian; Wismeijer, Daniel

2012-01-01

To evaluate the air powder abrasive treatment as an implant surface cleaning method for peri-implantitis based on the existing literature. A PubMed search was conducted to find articles that reported on air powder abrasive treatment as an implant surface cleaning method for peri-implantitis. The studies evaluated cleaning efficiency and surface change as a result of the method. Furthermore, cell response toward the air powder abrasive-treated discs, reosseointegration, and clinical outcome after treatment is also reported. The PubMed search resulted in 27 articles meeting the inclusion criteria. In vitro cleaning efficiency of the method is reported to be high. The method resulted in minor surface changes on titanium specimens. Although the air powder abrasive-treated specimens showed sufficient levels of cell attachment and cell viability, the cell response decreased compared with sterile discs. Considerable reosseointegration between 39% and 46% and improved clinical parameters were reported after treatment when applied in combination with surgical treatment. The results of the treatment are influenced by the powder type used, the application time, and whether powder was applied surgically or nonsurgically. The in vivo data on air powder abrasive treatment as an implant surface cleaning method is not sufficient to draw definitive conclusions. However, in vitro results allow the clinician to consider the method as a promising option for implant surface cleaning in peri-implantitis treatment.

Combined VEGF and LMP-1 delivery enhances osteoprogenitor cell differentiation and ectopic bone formation.

PubMed

Wang, Xiuli; Cui, Fuai; Madhu, Vedavathi; Dighe, Abhijit S; Balian, Gary; Cui, Quanjun

2011-02-01

A novel strategy to enhance bone repair is to combine angiogenic factors and osteogenic factors. We combined vascular endothelial growth factor (VEGF) and LIM mineralization protein-1 (LMP-1) by using an internal ribosome entry site to link the genes within a single plasmid. We then evaluated the effects on osteoblastic differentiation in vitro and ectopic bone formation in vivo with a subcutaneously placed PLAGA scaffold loaded with a cloned mouse osteoprogenitor cell line, D1, transfected with plasmids containing VEGF and LMP-1 genes. The cells expressing both genes elevated mRNA expression of RunX2 and β-catenin and alkaline phosphatase activity compared to cells from other groups. In vivo, X-ray and micro-CT analysis of the retrieved implants revealed more ectopic bone formation at 2 and 3 weeks but not at 4 weeks compared to other groups. The results indicate that the combination of the therapeutic growth factors potentiates cell differentiation and may promote osteogenesis.

In vitro culture and characterization of human lung cancer circulating tumor cells isolated by size exclusion from an orthotopic nude-mouse model expressing fluorescent protein.

PubMed

Kolostova, Katarina; Zhang, Yong; Hoffman, Robert M; Bobek, Vladimir

2014-09-01

In the present study, we demonstrate an animal model and recently introduced size-based exclusion method for circulating tumor cells (CTCs) isolation. The methodology enables subsequent in vitro CTC-culture and characterization. Human lung cancer cell line H460, expressing red fluorescent protein (H460-RFP), was orthotopically implanted in nude mice. CTCs were isolated by a size-based filtration method and successfully cultured in vitro on the separating membrane (MetaCell®), analyzed by means of time-lapse imaging. The cultured CTCs were heterogeneous in size and morphology even though they originated from a single tumor. The outer CTC-membranes were blebbing in general. Abnormal mitosis resulting in three daughter cells was frequently observed. The expression of RFP ensured that the CTCs originated from lung tumor. These readily isolatable, identifiable and cultivable CTCs can be used to characterize individual patient cancers and for screening of more effective treatment.

A new tritium monitor design based on plasma source ion implantation technique

NASA Astrophysics Data System (ADS)

Nassar, Rafat Mohammad

Tritium is an important isotope of hydrogen. The availability of tritium in our environment is manifest through both natural and artificial sources. Consequently, the requirement for tritium handling and usage will continue to increase in the future. An important future contributor is nuclear fusion power plants and facilities. Essential safety regulations and procedures require effective monitoring and measurements of tritium concentrations in workplaces. The unique characteristics of tritium impose an important role on the criteria for its detection and measurement. As tritium decays by the emission of soft beta particles, maximum 18 keV, it cannot be readily detected by commonly used detectors. Specially built monitors are required. Additional complications occur due to the presence of other radioactive isotopes or ambient radiation fields and because of the high diffusivity of tritium. When it is in oxidized form it is 25000 times more hazardous biologically than when in elemental form. Therefore, contamination of the monitor is expected and compound specific monitors are important. A summary is given of the various well known methods of detecting tritium-in-air. This covers the direct as well as the indirect measuring techniques, although each has been continually improved and further developed, nevertheless, each has its own limitations. Ionization chambers cannot discriminate against airborne P emitters. Proportional counters have a narrow operating range, 3-4 decades, and have poor performance in relatively high humid environments and require a dry counting gas. Liquid scintillation counters are sensitive, but inspection of the sample is slow and they produce chemical liquid waste. A new way to improve the sensitivity of detecting tritium with plastic scintillators has been developed. The technique is based on a non-line-of-sight implantation of tritium ions into a 20 mum plastic scintillator using a plasma source ion implantation (PSII) technique, This type of source is different, superior to the line-of-sight implantation and requires no additional beam handling. It is capable of implanting ion species in a broad beam configuration into the entire surface of a target. The technique requires a special ion source with special characteristics of the type obtained from a surfatron plasma source. This ion source has a large high ion density plasma with minimum contamination and produces ions of low temperature. It was constructed to ionize the sampled air and to produce a plasma over a wide range of pressure, 4-0.1 mTorr. A plasma source ion implantation cell was designed and constructed using mathematical modeling with personal computer, to optimize the essential variables of the design and to estimate the implantation rate under different operation conditions. Also, a high voltage pulse modulator was designed and constructed to produce a series of 10 musec pulses (up to 2 MHz) with a maximum magnitude of -60 kV. The developed device was capable of ionizing air samples and implanting the resulting ions into a plastic scintillator. Two different methods to enhance the collection and deposition of the tritium ions, have been proposed and assessed. A movable prototype device for monitoring environmental tritium in air has been designed and constructed. Although this prototype was not fully tested, the primary calculations have shown that measurable concentrations of tritium ions can be collected from an air sample, with tritium activity ranging from 0.3 Bq/cm3 down to 0.03 mBq/cm3, in a short time, to the order of seconds, on-line. This sensitivity fulfills the requirement for environmental monitoring.

A Retrospective Multicentre Cohort Review of Patient Characteristics and Surgical Aspects versus the Long-Term Outcomes for Recipients of a Fully Implantable Active Middle Ear Implant

PubMed Central

Lefebvre, Philippe P.; Gisbert, Javier; Cuda, Domenico; Tringali, Stéphane; Deveze, Arnaud

2017-01-01

Objective To summarise treatment outcomes compared to surgical and patient variables for a multicentre recipient cohort using a fully implantable active middle ear implant for hearing impairment. To describe the authors' preferred surgical technique to determine microphone placement. Study Design Multicentre retrospective, observational survey. Setting Five tertiary referral centres. Patients Carina recipients (66 ears, 62 subjects) using the current Cochlear® Carina® System or the legacy device, the Otologics® Fully Implantable Middle Ear, with a T2 transducer. Methods Patient file review and routine clinical review. Patient outcomes assessed were satisfaction, daily use and feedback reports at the first fitting and ≥12 months after implantation. Descriptive and statistical analysis of correlations of variables and their influence on outcomes was performed. Independently reported preferred methods for microphone placement are collectively summarised. Results The average implant experience was 3.5 years. Satisfaction increased significantly over time (p < 0.05). No correlation with covariates examined was observed. Feedback significantly decreased over time, showing a significant correlation with microphone location, primary motivation, gender, age at implantation, and contralateral hearing aid use (p < 0.05). Patient satisfaction was inversely correlated with reports of system feedback (p < 0.05). The implantable microphone was most commonly on the posterior inferior mastoid line, in 42/66 (65%) cases, correlating with less likelihood for feedback and consistent with author surgical preference. Conclusion Carina recipients in this study present as satisfied consistent daily users with very few reports of persistent feedback. As microphone location is an influencing factor, a careful surgical consideration of microphone placement is required. The authors prefer a posterior inferior mastoid line position whenever possible. PMID:28052264

The effect of an Ahmed glaucoma valve implant on corneal endothelial cell density in children with glaucoma secondary to uveitis.

PubMed

Kalinina Ayuso, Viera; Scheerlinck, Laura M; de Boer, Joke H

2013-03-01

To assess the effect of Ahmed glaucoma valve implants on corneal endothelial cell density (ECD) in children with uveitic glaucoma. Cross-sectional study. setting: Institutional. patientpopulation: Eighty eyes from 42 patients diagnosed with uveitis before the age of 16. Twenty-eight eyes had an Ahmed glaucoma valve implant because of secondary glaucoma. Fifty-two eyes without an implant served as controls. intervention orobservationprocedure(s): Corneal ECD was examined cross-sectionally using a noncontact specular microscope. Univariate and multivariate generalized estimating equations analyses with correction for paired eyes were performed. mainoutcomemeasure(s): Correlation of ECD with the presence of an Ahmed glaucoma valve implant and with the time following implantation. ECD was significantly lower in the Ahmed glaucoma valve group than in controls (2359 and 3088 cells/mm(2), respectively; P < .001) following an average of 3.5 years after Ahmed glaucoma valve implantation. Presence of an Ahmed glaucoma valve implant, previous intraocular surgery, age, duration of uveitis, and history of corneal touch by the implant tube were all significantly associated with decreased ECD. Following a multivariate analysis, presence of an Ahmed glaucoma valve implant (B = -340; adjusted P < .011) and older age (B = -58; adjusted P = .005) remained independently associated with decreased ECD. Within the implant group, the age-adjusted time interval following Ahmed glaucoma valve implantation was highly correlated with decreased ECD (B = -558, P < .001). Ahmed glaucoma valve implants in children with uveitic glaucoma are independently associated with decreased ECD, and this effect is associated with the time interval following Ahmed glaucoma valve implantation. Copyright © 2013 Elsevier Inc. All rights reserved.

Histamine release and fibrinogen adsorption mediate acute inflammatory responses to biomaterial implants in humans

PubMed Central

Zdolsek, Johann; Eaton, John W; Tang, Liping

2007-01-01

Background Medical implants often fail as a result of so-called foreign body reactions during which inflammatory cells are recruited to implant surfaces. Despite the clinical importance of this phenomenon, the mechanisms involved in these reactions to biomedical implants in humans are not well understood. The results from animal studies suggest that both fibrinogen adsorption to the implant surface and histamine release by local mast cells are involved in biomaterial-mediated acute inflammatory responses. The purpose of this study was to test this hypothesis in humans. Methods Thirteen male medical student volunteers (Caucasian, 21–30 years of age) were employed for this study. To assess the importance of fibrinogen adsorption, six volunteers were implanted with polyethylene teraphthalate disks pre-coated with their own (fibrinogen-containing) plasma or (fibrinogen-free) serum. To evaluate the importance of histamine, seven volunteers were implanted with uncoated disks with or without prior oral administration of histamine receptor antagonists. The acute inflammatory response was estimated 24 hours later by measuring the activities of implant-associated phagocyte-specific enzymes. Results Plasma coated implants accumulated significantly more phagocytes than did serum coated implants and the recruited cells were predominantly macrophage/monocytes. Administration of both H1 and H2 histamine receptor antagonists greatly reduced the recruitment of macrophages/monocytes and neutrophils on implant surfaces. Conclusion In humans – as in rodents – biomaterial-mediated inflammatory responses involve at least two crucial events: histamine-mediated phagocyte recruitment and phagocyte accumulation on implant surfaces engendered by spontaneously adsorbed host fibrinogen. Based on these results, we conclude that reducing fibrinogen:surface interactions should enhance biocompatibility and that administration of histamine receptor antagonists prior to, and shortly after, medical device implantation should improve the functionality and longevity of medical implants. PMID:17603911

Minimal functional β-cell mass in intraportal implants that reduces glycemic variability in type 1 diabetic recipients.

PubMed

Gillard, Pieter; Hilbrands, Robert; Van de Velde, Ursule; Ling, Zhidong; Lee, Da Hae; Weets, Ilse; Gorus, Frans; De Block, Christophe; Kaufman, Leonard; Mathieu, Chantal; Pipeleers, Daniel; Keymeulen, Bart

2013-11-01

Previous work has shown a correlation between β-cell number in cultured islet cell grafts and their ability to induce C-peptide secretion after intraportal implantation in C-peptide-negative type1 diabetic patients. In this cross-sectional study, we examined the minimal functional β-cell mass (FBM) in the implant that induces metabolic improvement. Glucose clamps assessed FBM in 42 recipients with established implants. C-peptide release during each phase was expressed as percentage of healthy control values. Its relative magnitude during a second hyperglycemic phase was most discriminative and therefore selected as a parameter to be correlated with metabolic effects. Recipients with functioning β-cell implants exhibited average FBM corresponding to 18% of that in normal control subjects (interquartile range 10-33%). Its relative magnitude negatively correlated with HbA1c levels (r = -0.47), daily insulin dose (r = -0.75), and coefficient of variation of fasting glycemia (CVfg) (r = -0.78, retained in multivariate analysis). A correlation between FBM and CVfg <25% appeared from the receiver operating characteristic curve (0.97 [95% CI 0.93-1.00]). All patients with FBM >37% exhibited CVfg <25% and a >50% reduction of their pretransplant CVfg; this occurred in none with FBM <5%. Implants with FBM >18% reduced CVfg from a median pretransplant value of 46 to <25%. Glucose clamping assesses the degree of restoration in FBM achieved by islet cell implants. Values >37% of normal control subjects appear needed to reduce glycemic variability in type 1 diabetic recipients. Further studies should examine whether the test can help guide decisions on additional islet cell transplants and on adjusting or stopping immunotherapy.

Migration of lymphocytes on fibronectin-coated surfaces: temporal evolution of migratory parameters

NASA Technical Reports Server (NTRS)

Bergman, A. J.; Zygourakis, K.; McIntire, L. V. (Principal Investigator)

1999-01-01

Lymphocytes typically interact with implanted biomaterials through adsorbed exogenous proteins. To provide a more complete characterization of these interactions, analysis of lymphocyte migration on adsorbed extracellular matrix proteins must accompany the commonly performed adhesion studies. We report here a comparison of the migratory and adhesion behavior of Jurkat cells (a T lymphoblastoid cell line) on tissue culture treated and untreated polystyrene surfaces coated with various concentrations of fibronectin. The average speed of cell locomotion showed a biphasic response to substrate adhesiveness for cells migrating on untreated polystyrene and a monotonic decrease for cells migrating on tissue culture-treated polystyrene. A modified approach to the persistent random walk model was implemented to determine the time dependence of cell migration parameters. The random motility coefficient showed significant increases with time when cells migrated on tissue culture-treated polystyrene surfaces, while it remained relatively constant for experiments with untreated polystyrene plates. Finally, a cell migration computer model was developed to verify our modified persistent random walk analysis. Simulation results suggest that our experimental data were consistent with temporally increasing random motility coefficients.

Relationship between oral cancer and implants: clinical cases and systematic literature review

PubMed Central

López-López, José; Roselló-Llabrés, Xavier; Rodríguez-Argueta, Oscar-Francisco; Chimenos-Küstner, Eduardo

2012-01-01

The use of implants for oral rehabilitation of edentulous spaces has recently been on the increase, which has also led to an increase in complications such as peri-implant inflammation or periimplantitis. Chronic inflammation is a risk factor for developing oral squamous cell carcinoma (OSCC). Objectives: To review the literature of cases that associate implant placement with the development of oral cancer. Study design: We present two clinical cases and a systematic review of literature published on the relationship between oral cancer and implants. Results: We found 13 articles published between the years 1996 and 2009, referencing 18 cases in which the osseointegrated implants are associated with oral squamous cell carcinoma. Of those, 6 articles were excluded because they did not meet the inclusion criteria. Of the 18 cases reported, only 7 cases did not present a previous history of oral cancer or cancer in other parts of the body. Conclusions: Based on the review of these cases, a clear cause-effect relationship cannot be established, although it can be deduced that there is a possibility that implant treatment may constitute an irritant and/or inflammatory cofactor which contributes to the formation and/or development of OSCC. Key words: Cancer, oral cancer, dental implants, oral squamous cell carcinoma, dental implants complications. PMID:21743414

Photoluminescence of magnesium-associated color centers in LiF crystals implanted with magnesium ions

NASA Astrophysics Data System (ADS)

Nebogin, S. A.; Ivanov, N. A.; Bryukvina, L. I.; V. Shipitsin, N.; E. Rzhechitskii, A.; Papernyi, V. L.

2018-05-01

In the present paper, the effect of magnesium nanoparticles implanted in a LiF crystal on the optical properties of color centers is studied. The transmittance spectra and AFM images demonstrate effective formation of the color centers and magnesium nanoparticles in an implanted layer of ∼ 60-100 nm in thickness. Under thermal annealing, a periodical structure is formed on the surface of the crystal and in the implanted layer due to self-organization of the magnesium nanoparticles. Upon excitation by argon laser with a wavelength of 488 nm at 5 K, in a LiF crystal, implanted with magnesium ions as well as in heavily γ-irradiated LiF: Mg crystals, luminescence of the color centers at λmax = 640 nm with a zero-phonon line at 601.5 nm is observed. The interaction of magnesium nanoparticles and luminescing color centers in a layer implanted with magnesium ions has been revealed. It is shown that the luminescence intensity of the implanted layer at a wavelength of 640 nm is by more than two thousand times higher than that of a heavily γ-irradiated LiF: Mg crystal. The broadening of the zero-phonon line at 601.5 nm in the spectrum of the implanted layer indicates the interaction of the emitting quantum system with local field of the surface plasmons of magnesium nanoparticles. The focus of this work is to further optimize the processing parameters in a way to result in luminescence great enhancement of color centers by magnesium nanoparticles in LiF.

Evaluation of imaging biomarkers for identification of single cancer cells in blood

NASA Astrophysics Data System (ADS)

Odaka, Masao; Kim, Hyonchol; Girault, Mathias; Hattori, Akihiro; Terazono, Hideyuki; Matsuura, Kenji; Yasuda, Kenji

2015-06-01

A method of discriminating single cancer cells from whole blood cells based on their morphological visual characteristics (i.e., “imaging biomarker”) was examined. Cells in healthy rat blood, a cancer cell line (MAT-LyLu), and cells in cancer-cell-implanted rat blood were chosen as models, and their bright-field (BF, whole-cell morphology) and fluorescence (FL, nucleus morphology) images were taken by an on-chip multi-imaging flow cytometry system and compared. Eight imaging biomarker indices, i.e., cellular area in a BF image, nucleus area in an FL image, area ratio of a whole cell and its nucleus, distance of the mass center between a whole cell and nucleus, cellular and nucleus perimeter, and perimeter ratios were calculated and analyzed using the BF and FL images taken. Results show that cancer cells can be clearly distinguished from healthy blood cells using correlation diagrams for cellular and nucleus areas as two different categories. Moreover, a portion of cancer cells showed a low nucleus perimeter ratio less than 0.9 because of the irregular nucleus morphologies of cancer cells. These results indicate that the measurements of imaging biomarkers are practically applicable to identifying cancer cells in blood.

Biofunctionalization of silicone rubber with microgroove-patterned surface and carbon-ion implantation to enhance biocompatibility and reduce capsule formation.

PubMed

Lei, Ze-Yuan; Liu, Ting; Li, Wei-Juan; Shi, Xiao-Hua; Fan, Dong-Li

Silicone rubber implants have been widely used to repair soft tissue defects and deformities. However, poor biocompatibility can elicit capsule formation, usually resulting in prosthesis contracture and displacement in long-term usage. To overcome this problem, this study investigated the properties of silicone rubber materials with or without a microgroove-patterned surface and with or without carbon (C)-ion implantation. Atomic force microscopy, X-ray photoelectron spectroscopy, and a water contact angle test were used to characterize surface morphology and physicochemical properties. Cytocompatibility was investigated by a cell adhesion experiment, immunofluorescence staining, a Cell Counting Kit-8 assay, and scanning electron microscopy in vitro. Histocompatibility was evaluated by studying the inflammatory response and fiber capsule formation that developed after subcutaneous implantation in rats for 7 days, 15 days, and 30 days in vivo. Parallel microgrooves were found on the surfaces of patterned silicone rubber (P-SR) and patterned C-ion-implanted silicone rubber (PC-SR). Irregular larger peaks and deeper valleys were present on the surface of silicone rubber implanted with C ions (C-SR). The silicone rubber surfaces with microgroove patterns had stable physical and chemical properties and exhibited moderate hydrophobicity. PC-SR exhibited moderately increased dermal fibroblast cell adhesion and growth, and its surface microstructure promoted orderly cell growth. Histocompatibility experiments on animals showed that both the anti-inflammatory and antifibrosis properties of PC-SR were slightly better than those of the other materials, and there was also a lower capsular contracture rate and less collagen deposition around implants made from PC-SR. Although the surface chemical properties, dermal fibroblast cell growth, and cell adhesion were not changed by microgroove pattern modification, a more orderly cell arrangement was obtained, leading to enhanced biocompatibility and reduced capsule formation. Thus, this approach to the modification of silicone rubber, in combination with C-ion implantation, should be considered for further investigation and application.

Risk factors for central line-associated bloodstream infection in pediatric oncology patients with a totally implantable venous access port: A cohort study.

PubMed

Viana Taveira, Michelle Ribeiro; Lima, Luciana Santana; de Araújo, Cláudia Corrêa; de Mello, Maria Júlia Gonçalves

2017-02-01

Totally implantable venous access ports (TIVAPs) are used for prolonged central venous access, allowing the infusion of chemotherapy and other fluids and improving the quality of life of children with cancer. TIVAPs were developed to reduce the infection rates associated with central venous catheters; however, infectious events remain common and have not been fully investigated in pediatric oncology patients. A retrospective cohort was formed to investigate risk factors for central line-associated bloodstream infection (CLABSI) in pediatric cancer patients. Sociodemographic, clinical, and TIVAP insertion-related variables were evaluated, with the endpoint being the first CLABSI. A Kaplan-Meier analysis was performed to determine CLABSI-free catheter survival. Overall, 188 children were evaluated over 77,541 catheter days, with 94 being diagnosed with CLABSI (50%). Although coagulase-negative staphylococci were the pathogens most commonly isolated, Gram-negative microorganisms (46.8%) were also prevalent. In the multivariate analysis, factors that increased the risk for CLABSI were TIVAP insertion prior to chemotherapy (risk ratio [RR] = 1.56; P < 0.01), white blood cell count less than 1,000 mm -3 on the day of implantation (RR = 1.64; P < 0.01), and chronic malnutrition (RR = 1.41; P < 0.05). Median time without CLABSI following TIVAP insertion was 74.5 days. Risk factors for CLABSI in pediatric cancer patients with a TIVAP may be related to the severity of the child's condition at catheter insertion. Insertion of the catheter before chemotherapy and unfavorable conditions such as malnutrition and bone marrow aplasia can increase the risk of CLABSI. Protocols must be revised and surveillance increased over the first 10 weeks of treatment. © 2016 Wiley Periodicals, Inc.

UV-activated 7-dehydrocholesterol-coated titanium implants promote differentiation of human umbilical cord mesenchymal stem cells into osteoblasts.

PubMed

Satué, María; Ramis, Joana M; Monjo, Marta

2016-01-01

Vitamin D metabolites are essential for bone regeneration and mineral homeostasis. The vitamin D precursor 7-dehydrocholesterol can be used after UV irradiation to locally produce active vitamin D by osteoblastic cells. Furthermore, UV-irradiated 7-dehydrocholesterol is a biocompatible coating for titanium implants with positive effects on osteoblast differentiation. In this study, we examined the impact of titanium implants surfaces coated with UV-irradiated 7-dehydrocholesterol on the osteogenic differentiation of human umbilical cord mesenchymal stem cells. First, the synthesis of cholecalciferol (D3) was achieved through the incubation of the UV-activated 7-dehydrocholesterol coating for 48 h at 23℃. Further, we investigated in vitro the biocompatibility of this coating in human umbilical cord mesenchymal stem cells and its potential to enhance their differentiation towards the osteogenic lineage. Human umbilical cord mesenchymal stem cells cultured onto UV-irradiated 7-dehydrocholesterol-coated titanium implants surfaces, combined with osteogenic supplements, upregulated the gene expression of several osteogenic markers and showed higher alkaline phosphatase activity and calcein blue staining, suggesting increased mineralization. Thus, our results show that the use of UV irradiation on 7-dehydrocholesterol -treated titanium implants surfaces generates a bioactive coating that promotes the osteogenic differentiation of human umbilical cord mesenchymal stem cells, with regenerative potential for improving osseointegration in titanium-based bone anchored implants. © The Author(s) 2015.

Evaluation of the effect of the degree of acetylation on the inflammatory response to 3D porous chitosan scaffolds.

PubMed

Barbosa, Judite N; Amaral, Isabel F; Aguas, Artur P; Barbosa, Mário A

2010-04-01

The effect of the degree of acetylation (DA) of 3D chitosan (Ch) scaffolds on the inflammatory reaction was investigated. Chitosan porous scaffolds with DAs of 4 and 15% were implanted using a subcutaneous air-pouch model of inflammation. The initial acute inflammatory response was evaluated 24 and 48 h after implantation. To characterize the initial response, the recruitment and adhesion of inflammatory cells to the implant site was studied. The fibrous capsule formation and the infiltration of inflammatory cells within the scaffolds were evaluated for longer implantation times (2 and 4 weeks). Chitosan with DA 15% attracted the highest number of leukocytes to the implant site. High numbers of adherent inflammatory cells were also observed in this material. For longer implantation periods Ch scaffolds with a DA of 15% induced the formation of a thick fibrous capsule and a high infiltration of inflammatory cells within the scaffold. Our results indicate that the biological response to implanted Ch scaffolds was influenced by the DA. Chitosan with a DA of 15% induce a more intense inflammatory response when compared with DA 4% Ch. Because inflammation and healing are interrelated, this result may provide clues for the relative importance of acetyl and amine functional groups in tissue repair and regeneration.

Increasing the Dose of Autologous Chondrocytes Improves Articular Cartilage Repair: Histological and Molecular Study in the Sheep Animal Model.

PubMed

Guillén-García, Pedro; Rodríguez-Iñigo, Elena; Guillén-Vicente, Isabel; Caballero-Santos, Rosa; Guillén-Vicente, Marta; Abelow, Stephen; Giménez-Gallego, Guillermo; López-Alcorocho, Juan Manuel

2014-04-01

We hypothesized that implanting cells in a chondral defect at a density more similar to that of the intact cartilage could induce them to synthesize matrix with the features more similar to that of the uninjured one. We compared the implantation of different doses of chondrocytes: 1 million (n = 5), 5 million (n = 5), or 5 million mesenchymal cells (n = 5) in the femoral condyle of 15 sheep. Tissue generated by microfracture at the trochlea, and normal cartilage from a nearby region, processed as the tissues resulting from the implantation, were used as references. Histological and molecular (expression of type I and II collagens and aggrecan) studies were performed. The features of the cartilage generated by implantation of mesenchymal cells and elicited by microfractures were similar and typical of a poor repair of the articular cartilage (presence of fibrocartilage, high expression of type I collagen and a low mRNA levels of type II collagen and aggrecan). Nevertheless, in the samples obtained from tissues generated by implantation of chondrocytes, hyaline-like cartilage, cell organization, low expression rates of type I collagen and high levels of mRNA corresponding to type II collagen and aggrecan were observed. These histological features, show less variability and are more similar to those of the normal cartilage used as control in the case of 5 million cells implantation than when 1 million cells were used. The implantation of autologous chondrocytes in type I/III collagen membranes at high density could be a promising tool to repair articular cartilage.

Cryo-image Analysis of Tumor Cell Migration, Invasion, and Dispersal in a Mouse Xenograft Model of Human Glioblastoma Multiforme

PubMed Central

Qutaish, Mohammed Q.; Sullivant, Kristin E.; Burden-Gulley, Susan M.; Lu, Hong; Roy, Debashish; Wang, Jing; Basilion, James P.; Brady-Kalnay, Susann M.; Wilson, David L.

2012-01-01

Purpose The goals of this study were to create cryo-imaging methods to quantify characteristics (size, dispersal, and blood vessel density) of mouse orthotopic models of glioblastoma multiforme (GBM) and to enable studies of tumor biology, targeted imaging agents, and theranostic nanoparticles. Procedures Green fluorescent protein-labeled, human glioma LN-229 cells were implanted into mouse brain. At 20–38 days, cryo-imaging gave whole brain, 4-GB, 3D microscopic images of bright field anatomy, including vasculature, and fluorescent tumor. Image analysis/visualization methods were developed. Results Vessel visualization and segmentation methods successfully enabled analyses. The main tumor mass volume, the number of dispersed clusters, the number of cells/cluster, and the percent dispersed volume all increase with age of the tumor. Histograms of dispersal distance give a mean and median of 63 and 56 μm, respectively, averaged over all brains. Dispersal distance tends to increase with age of the tumors. Dispersal tends to occur along blood vessels. Blood vessel density did not appear to increase in and around the tumor with this cell line. Conclusion Cryo-imaging and software allow, for the first time, 3D, whole brain, microscopic characterization of a tumor from a particular cell line. LN-229 exhibits considerable dispersal along blood vessels, a characteristic of human tumors that limits treatment success. PMID:22125093

Integrating Microtissues in Nanofiber Scaffolds for Regenerative Nanomedicine

PubMed Central

Keller, Laetitia; Wagner, Quentin; Offner, Damien; Eap, Sandy; Musset, Anne-Marie; Arruebo, Manuel; Kelm, Jens M.; Schwinté, Pascale; Benkirane-Jessel, Nadia

2015-01-01

A new generation of biomaterials focus on smart materials incorporating cells. Here, we describe a novel generation of synthetic nanofibrous implant functionalized with living microtissues for regenerative nanomedicine. The strategy designed here enhances the effectiveness of therapeutic implants compared to current approaches used in the clinic today based on single cells added to the implant. PMID:28793604

Appearance of low signal intensity lines in MRI of silicone breast implants.

PubMed

Stroman, P W; Rolland, C; Dufour, M; Grondin, P; Guidoin, R G

1996-05-01

Magnetic resonance (MR) images of five explanted mammary prostheses were obtained with a 1.5 T GE Signa system using a conventional spin-echo pulse sequence, in order to investigate the low-intensity curvilinear lines which may be observed in MR images of silicone gel-filled breast implants under pressure from fibrous capsules. MR images showed ellipsoid prostheses, often containing multiple low-intensity curvilinear lines which in some cases presented an appearance very similar to that of the linguine sign. Upon opening the fibrous capsules, however, all of the prostheses were found to be completely intact demonstrating that the appearance of multiple low signal intensity curvilinear lines in MR images of silicone gel-filled prostheses is not necessarily a sign of prosthesis rupture. The MR image features which are specific to the linguine sign must be more precisely defined.

Cell recruitment by amnion chorion grafts promotes neovascularization.

PubMed

Maan, Zeshaan N; Rennert, Robert C; Koob, Thomas J; Januszyk, Michael; Li, William W; Gurtner, Geoffrey C

2015-02-01

Nonhealing wounds are a significant health burden. Stem and progenitor cells can accelerate wound repair and regeneration. Human amniotic membrane has demonstrated efficacy in promoting wound healing, though the underlying mechanisms remain unknown. A dehydrated human amnion chorion membrane (dHACM) was tested for its ability to recruit hematopoietic progenitor cells to a surgically implanted graft in a murine model of cutaneous ischemia. dHACM was subcutaneously implanted under elevated skin (ischemic stimulus) in either wild-type mice or mice surgically parabiosed to green fluorescent protein (GFP) + reporter mice. A control acellular dermal matrix, elevated skin without an implant, and normal unwounded skin were used as controls. Wound tissue was harvested and processed for histology and flow cytometric analysis. Implanted dHACMs recruited significantly more progenitor cells compared with controls (*P < 0.05) and displayed in vivo SDF-1 expression with incorporation of CD34 + progenitor cells within the matrix. Parabiosis modeling confirmed the circulatory origin of recruited cells, which coexpressed progenitor cell markers and were localized to foci of neovascularization within implanted matrices. In summary, dHACM effectively recruits circulating progenitor cells, likely because of stromal derived factor 1 (SDF-1) expression. The recruited cells express markers of "stemness" and localize to sites of neovascularization, providing a partial mechanism for the clinical efficacy of human amniotic membrane in the treatment of chronic wounds. Copyright © 2015 Elsevier Inc. All rights reserved.

Cell recruitment by amnion chorion grafts promotes neovascularization

PubMed Central

Koob, Thomas J.; Januszyk, Michael; Li, William W.; Gurtner, Geoffrey C.

2015-01-01

Background Nonhealing wounds are a significant health burden. Stem and progenitor cells can accelerate wound repair and regeneration. Human amniotic membrane has demonstrated efficacy in promoting wound healing, though the underlying mechanisms remain unknown. A dehydrated human amnion chorion membrane (dHACM) was tested for its ability to recruit hematopoietic progenitor cells to a surgically implanted graft in a murine model of cutaneous ischemia. Methods dHACM was subcutaneously implanted under elevated skin (ischemic stimulus) in either wild-type mice or mice surgically parabiosed to green fluorescent protein (GFP) + reporter mice. A control acellular dermal matrix, elevated skin without an implant, and normal unwounded skin were used as controls. Wound tissue was harvested and processed for histology and flow cytometric analysis. Results Implanted dHACMs recruited significantly more progenitor cells compared with controls (*P < 0.05) and displayed in vivo SDF-1 expression with incorporation of CD34 + progenitor cells within the matrix. Parabiosis modeling confirmed the circulatory origin of recruited cells, which coexpressed progenitor cell markers and were localized to foci of neovascularization within implanted matrices. Conclusions In summary, dHACM effectively recruits circulating progenitor cells, likely because of stromal derived factor 1 (SDF-1) expression. The recruited cells express markers of “stemness” and localize to sites of neovascularization, providing a partial mechanism for the clinical efficacy of human amniotic membrane in the treatment of chronic wounds. PMID:25266600

Antitumor immune activity by chemokine CX3CL1 in an orthotopic implantation of lung cancer model in vivo.

PubMed

Kee, Ji-Ye; Arita, Yoshihisa; Shinohara, Kanna; Ohashi, Yasukata; Sakurai, Hiroaki; Saiki, Ikuo; Koizumi, Keiichi

2013-01-01

Due to their chemoattractant properties stimulating the accumulation of infiltrating immune cells in tumors, chemokines are known to have antitumor effects. Fractalkine, a unique CX3C chemokine, is expressed in activated endothelial cells, while its receptor, CX3CR1, is expressed in cytolytic immune cells, such as natural killer cells, monocytes and some CD8 + T cells. The biological properties of cancer cells are affected by the implantation organ and differences in immune systems, requiring cancer implantation in orthotopic organs in an in vivo experiment. To develop new therapy strategies for lung cancer, an animal model reflecting the clinical features of lung cancer was previously established. This study aimed to determine whether CX3CL1-induced biological functions should be used for immune cell-based gene therapy of lung cancer in the orthotopic implantation model. An orthotopic intrapulmonary implantation of CX3CL1-stable expression in mouse lung cancer (LLC-CX3CL1) was performed to analyze growth. Results showed a significant decrease in tumor growth in the lung compared to the control cells (LLC-mock). Furthermore, the antitumor effects of CX3CL1 were derived from natural killer cell activities in the depletion experiment in vivo . Therefore, CX3CL1 has the potential of a useful therapeutic target in lung cancer.

Plasma-sprayed titanium coating to polyetheretherketone improves the bone-implant interface.

PubMed

Walsh, William R; Bertollo, Nicky; Christou, Chrisopher; Schaffner, Dominik; Mobbs, Ralph J

2015-05-01

Rapid and stable fixation at the bone-implant interface would be regarded as one of the primary goals to achieve clinical efficacy, regardless of the surgical site. Although mechanical and physical properties of polyetheretherketone (PEEK) provide advantages for implant devices, the hydrophobic nature and the lack of direct bone contact remains a limitation. To examine the effects of a plasma-sprayed titanium coated PEEK on the mechanical and histologic properties at the bone-implant interface. A preclinical laboratory study. Polyetheretherketone and plasma-sprayed titanium coated PEEK implants (Ti-bond; Spinal Elements, Carlsbad, CA, USA) were placed in a line-to-line manner in cortical bone and in a press-fit manner in cancellous bone of adult sheep using an established ovine model. Shear strength was assessed in the cortical sites at 4 and 12 weeks, whereas histology was performed in cortical and cancellous sites at both time points. The titanium coating dramatically improved the shear strength at the bone-implant interface at 4 weeks and continued to improve with time compared with PEEK. Direct bone ongrowth in cancellous and cortical sites can be achieved using a plasma-sprayed titanium coating on PEEK. Direct bone to implant bonding can be achieved on PEEK in spite of its hydrophobic nature using a plasma-sprayed titanium coating. The plasma-sprayed titanium coating improved mechanical properties in the cortical sites and the histology in cortical and cancellous sites. Copyright © 2015 Elsevier Inc. All rights reserved.

Learning about Sickle Cell Disease

MedlinePlus

... used in conjunction with in vitro fertilization, called pre-implantation genetic diagnosis (PGD), enables parents who carry the sickle cell trait to test embryos for the defective gene before implantation, and ...

A living thick nanofibrous implant bifunctionalized with active growth factor and stem cells for bone regeneration

PubMed Central

Eap, Sandy; Keller, Laetitia; Schiavi, Jessica; Huck, Olivier; Jacomine, Leandro; Fioretti, Florence; Gauthier, Christian; Sebastian, Victor; Schwinté, Pascale; Benkirane-Jessel, Nadia

2015-01-01

New-generation implants focus on robust, durable, and rapid tissue regeneration to shorten recovery times and decrease risks of postoperative complications for patients. Herein, we describe a new-generation thick nanofibrous implant functionalized with active containers of growth factors and stem cells for regenerative nanomedicine. A thick electrospun poly(ε-caprolactone) nanofibrous implant (from 700 μm to 1 cm thick) was functionalized with chitosan and bone morphogenetic protein BMP-7 as growth factor using layer-by-layer technology, producing fish scale-like chitosan/BMP-7 nanoreservoirs. This extracellular matrix-mimicking scaffold enabled in vitro colonization and bone regeneration by human primary osteoblasts, as shown by expression of osteocalcin, osteopontin, and bone sialoprotein (BSPII), 21 days after seeding. In vivo implantation in mouse calvaria defects showed significantly more newly mineralized extracellular matrix in the functionalized implant compared to a bare scaffold after 30 days’ implantation, as shown by histological scanning electron microscopy/energy dispersive X-ray microscopy study and calcein injection. We have as well bifunctionalized our BMP-7 therapeutic implant by adding human mesenchymal stem cells (hMSCs). The activity of this BMP-7-functionalized implant was again further enhanced by the addition of hMSCs to the implant (living materials), in vivo, as demonstrated by the analysis of new bone formation and calcification after 30 days’ implantation in mice with calvaria defects. Therefore, implants functionalized with BMP-7 nanocontainers associated with hMSCs can act as an accelerator of in vivo bone mineralization and regeneration. PMID:25709432

Less-Costly Ion Implantation of Solar Cells

NASA Technical Reports Server (NTRS)

Fitzgerald, D. J.

1984-01-01

Experiments point way toward more relaxed controls over ion-implanation dosage and uniformity in solar-cell fabrication. Data indicate cell performance, measured by output current density at fixed voltage, virtually same whether implant is particular ion species or broad-beam mixture of several species.

Long-term survival of donor bone marrow multipotent mesenchymal stromal cells implanted into the periosteum of patients with allogeneic graft failure.

PubMed

Kuzmina, L A; Petinati, N A; Sats, N V; Drize, N J; Risinskaya, N V; Sudarikov, A B; Vasilieva, V A; Drokov, M Y; Michalzova, E D; Parovichnikova, E N; Savchenko, V G

2016-09-01

The present study involved three patients with graft failure following allogeneic hematopoietic stem cell transplantation (allo-HSCT). We obtained multipotent mesenchymal stromal cells (MSCs) from the original hematopoietic cell donors and implanted these cells in the periosteum to treat long-term bone marrow aplasia. The results showed that in all patients endogenous blood formation was recovered 2 weeks after MSC administration. Donor MSCs were found in recipient bone marrow three and 5 months following MSC implantation. Thus, our findings indicate that functional donor MSCs can persist in patient bone marrow.

Enhancement of matrix metalloproteinases 2 and 9 accompanied with neurogenesis following collagen glycosaminoglycan matrix implantation after surgical brain injury.

PubMed

Hsu, Wei-Cherng; Yu, Chun-Hsien; Kung, Woon-Man; Huang, Kuo-Feng

2018-06-01

Surgical brain injury may result in irreversible neurological deficits. Our previous report showed that partial regeneration of a traumatic brain lesion is achieved by implantation of collagen glycosaminoglycan (CGM). Matrix metalloproteinases (MMPs) may play an important role in neurogenesis but there is currently a lack of studies displaying the relationship between the stimulation of MMPs and neurogenesis after collagen glycosaminoglycan implantation following surgical brain trauma. The present study was carried out to further examine the expression of MMP2 and MMP9 after implantation of collagen glycosaminoglycan (CGM) following surgical brain trauma. Using the animal model of surgically induced brain lesion, we implanted CGM into the surgical trauma. Rats were thus divided into three groups: (1) sham operation group: craniotomy only; (2) lesion (L) group: craniotomy + surgical trauma lesion; (3) lesion + CGM (L + CGM) group: CGM implanted following craniotomy and surgical trauma lesion. Cells positive for SOX2 (marker of proliferating neural progenitor cells) and matrix metalloproteinases (MMP2 and MMP9) in the lesion boundary zone were assayed and analyzed by immunofluorescence and ELISA commercial kits, respectively. Our results demonstrated that following implantation of CGM after surgical brain trauma, significant increases in MMP2 + /SOX2 + cells and MMP9 + /SOX2 + cells were seen within the lesion boundary zone in the L + CGM group. Tissue protein concentrations of MMP2 and MMP9 also increased after CGM scaffold implantation. These findings suggest that implantation of a CGM scaffold alone after surgical brain trauma can enhance the expression of MMP2 and MMP9 accompanied by neurogenesis.

Tissue-Engineered Vocal Fold Mucosa Implantation in Rabbits.

PubMed

Shiba, Travis L; Hardy, Jordan; Luegmair, Georg; Zhang, Zhaoyan; Long, Jennifer L

2016-04-01

To assess phonatory function and wound healing of a tissue-engineered vocal fold mucosa (TE-VFM) in rabbits. An "artificial" vocal fold would be valuable for reconstructing refractory scars and resection defects, particularly one that uses readily available autologous cells and scaffold. This work implants a candidate TE-VFM after resecting native epithelium and lamina propria in rabbits. Prospective animal study. Research laboratory. Rabbit adipose-derived stem cells were isolated and cultured in three-dimensional fibrin scaffolds to form TE-VFM. Eight rabbits underwent laryngofissure, unilateral European Laryngologic Society type 2 cordectomy, and immediate reconstruction with TE-VFM. After 4 weeks, larynges were excised, phonated, and examined by histology. Uniform TE-VFM implants were created, with rabbit mesenchymal cells populated throughout fibrin hydrogels. Rabbits recovered uneventfully after implantation. Phonation was achieved in all, with mucosal waves evident at the implant site. Histology after 4 weeks showed resorbed fibrin matrix, continuous epithelium, and mildly increased collagen relative to contralateral unoperated vocal folds. Elastic fiber appearance was highly variable. Inflammatory cell infiltrate was limited to animals receiving sex-mismatched implants. TE-VFMs were successfully implanted into 8 rabbits, with minor evidence of scar formation and immune reaction. Vibration was preserved 4 weeks after resecting and reconstructing the complete vocal fold cover layer. Further studies will investigate the mechanism and durability of improvement. TE-VFM with autologous cells is a promising new approach for vocal fold reconstruction. © American Academy of Otolaryngology—Head and Neck Surgery Foundation 2016.

Cytocompatibility and uptake of halloysite clay nanotubes.

PubMed

Vergaro, Viviana; Abdullayev, Elshad; Lvov, Yuri M; Zeitoun, Andre; Cingolani, Roberto; Rinaldi, Ross; Leporatti, Stefano

2010-03-08

Halloysite is aluminosilicate clay with hollow tubular structure of 50 nm external diameter and 15 nm diameter lumen. Halloysite biocompatibility study is important for its potential applications in polymer composites, bone implants, controlled drug delivery, and for protective coating (e.g., anticorrosion or antimolding). Halloysite nanotubes were added to different cell cultures for toxicity tests. Its fluorescence functionalization by aminopropyltriethosilane (APTES) and with fluorescently labeled polyelectrolyte layers allowed following halloysite uptake by the cells with confocal laser scanning microscopy (CLSM). Quantitative Trypan blue and MTT measurements performed with two neoplastic cell lines model systems as a function of the nanotubes concentration and incubation time indicate that halloysite exhibits a high level of biocompatibility and very low cytotoxicity, rendering it a good candidate for household materials and medicine. A combination of transmission electron microscopy (TEM), scanning electron microscopy (SEM), and scanning force microscopy (SFM) imaging techniques have been employed to elucidate the structure of halloysite nanotubes.

Hemocompatibility and biocompatibility of antibacterial biomimetic hybrid films

DOE Office of Scientific and Technical Information (OSTI.GOV)

Coll Ferrer, M. Carme; Department of Materials Science and Engineering, University of Pennsylvania, Philadelphia, PA 19104; Eckmann, Uriel N.

In previous work, we developed novel antibacterial hybrid coatings based on dextran containing dispersed Ag NPs (∼ 5 nm, DEX-Ag) aimed to offer dual protection against two of the most common complications associated with implant surgery, infections and rejection of the implant. However, their blood-material interactions are unknown. In this study, we assess the hemocompatibility and biocompatibility of DEX-Ag using fresh blood and two cell lines of the immune system, monocytes (THP-1 cells) and macrophages (PMA-stimulated THP-1 cells). Glass, polyurethane (PU) and bare dextran (DEX) were used as reference surfaces. PU, DEX and DEX-Ag exhibited non-hemolytic properties. Relative to glassmore » (100%), platelet attachment on PU, DEX and DEX-Ag was 15%, 10% and 34%, respectively. Further, we assessed cell morphology and viability, pro-inflammatory cytokines expression (TNF-α and IL-1β), pro-inflammatory eicosanoid expression (Prostaglandin E{sub 2}, PGE{sub 2}) and release of reactive oxygen species (ROS, superoxide and H{sub 2}O{sub 2}) following incubation of the cells with the surfaces. The morphology and cell viability of THP-1 cells were not affected by DEX-Ag whereas DEX-Ag minimized spreading of PMA-stimulated THP-1 cells and caused a reduction in cell viability (16% relative to other surfaces). Although DEX-Ag slightly enhanced release of ROS, the expression of pro-inflammatory cytokines remained minimal with similar levels of PGE{sub 2}, as compared to the other surfaces studied. These results highlight low toxicity of DEX-Ag and hold promise for future applications in vivo. - Highlights: • We examined specific blood-contact reactions of dextran doped with Ag NPs coatings. • Biocompatibility was assessed with THP-1 cells and PMA-stimulated THP-1 cells. • Glass, polyurethane and dextran were used as reference surfaces. • Hybrid coatings exhibited non-hemolytic properties. • Low toxicity, inflammatory response and ROS suggest potential for in vivo use.« less

Heat shock protein-27 (HSP27) regulates STAT3 and eIF4G levels in first trimester human placenta.

PubMed

Shochet, Gali Epstein; Komemi, Oded; Sadeh-Mestechkin, Dana; Pomeranz, Meir; Fishman, Ami; Drucker, Liat; Lishner, Michael; Matalon, Shelly Tartakover

2016-12-01

During placental implantation, cytotrophoblast cells differentiate to extravillous trophoblast (EVT) cells that invade from the placenta into the maternal uterine blood vessels. The heat shock protein-27 (HSP27), the signal transducer and activator of transcription-3 (STAT3) and the eukaryotic translation initiation factor 4E (EIF4E) are involved in regulating EVT cell differentiation/migration. EIF4E and EIF4G compose the translation initiation complex, which is a major control point in protein translation. The molecular chaperone distinctiveness of HSP27 implies that it directly interferes with many target proteins. STAT3, EIF4E, and EIF4G were found to be HSP27 client proteins in tumor cells. We aimed to analyze if HSP27 regulate STAT3 and EIF4G levels in first trimester human placenta. We found that like STAT3, EIF4G is highly expressed in the EVT cells (immunohistochemistry). Silencing HSP27 in HTR-8/SVneo cells (siRNA, EVT cell line) and in placental explants reduced STAT3 level (47 and 33 %, respectively, p < 0.05). HSP27 silencing reduced the levels of STAT3 phosphorylation (33 % reduction, p < 0.05) and targets (IRF1, MUC1, MMP2/9 and EIF4E, 30-49 % reduction, p < 0.05) in the HTR-8/SVneo cells. Moreover, HSP27 silencing significantly reduced EIF4G level and elevated the level of its fragments in HTR-8/SVneo cells and in the placental explants (p < 0.05). In conclusion, Placental implantation and development are accompanied by trophoblast cell proliferation and differentiation, which necessitates intense protein translation and STAT3 activation. HSP27 was found to be regulator of translation initiation and STAT3 level. Therefore, it suggests that HSP27 is a key protein during placental development and trophoblast cell differentiation.

Effect of trehalose coating on basic fibroblast growth factor release from tailor-made bone implants.

PubMed

Choi, Sungjin; Lee, Jongil; Igawa, Kazuyo; Suzuki, Shigeki; Mochizuki, Manabu; Nishimura, Ryohei; Chung, Ung-il; Sasaki, Nobuo

2011-12-01

Artificial bone implants are often incorporated with osteoinductive factors to facilitate early bone regeneration. Calcium phosphate, the main component in artificial bone implants, strongly binds these factors, and in a few cases, the incorporated proteins are not released from the implant under conditions of physiological pH, thereby leading to reduction in their osteoinductivity. In this study, we coated tailor-made bone implants with trehalose to facilitate the release of basic fibroblast growth factor (bFGF). In an in vitro study, mouse osteoblastic cells were separately cultured for 48 hr in a medium with a untreated implant (T-), trehalose-coated implant (T+), bFGF-incorporated implant (FT-), and bFGF-incorporated implant with trehalose coating (FT+). In the FT+ group, cell viability was significantly higher than that in the other groups (P<0.05). Scanning electron microscopy (SEM) and X-ray diffraction (XRD) revealed that trehalose effectively covered the surface of the artificial bone implant without affecting the crystallinity or the mechanical strength of the artificial bone implant. These results suggest that coating artificial bone implants with trehalose could limit the binding of bFGF to calcium phosphate.

Does milling one-piece titanium dental implants induce osteocyte and osteoclast changes?

PubMed

Russe, P; Pascaretti-Grizon, F; Aguado, E; Goyenvale, E; Filmon, R; Baslé, M-F; Chappard, D

2011-06-01

One-piece dental implants avoid adverse effects sometimes associated with the traditional implant-abutment interface and may provide a suitable alternative to two-piece implants; however, one-piece implants often need in situ milling, which may exacerbate cell apoptosis from excessive heat at the bone-implant interface and induce secondary crestal bone loss. Twelve implants were placed in the metaphyses of two sheep under general anesthesia. Six implants were milled with a diamond bur while the other six implants remained intact. Animals were euthanized after four days, and bone blocks were harvested. Bone samples were studied without decalcification. Osteocytes were stained with Hoechst 33342 and osteoclasts by the TRAcP reaction. Both cell types, in the cortical and trabecular bone around the implant's cervical region, were counted utilizing morphometric methods. Values were compared to areas at a distance from the cervical region. No difference was observed between milled and unmilled implants, which suggested that the amount of generated heat did not provoke osteocyte loss or induce osteoclastogenesis. Intraoral abutment preparations did not increase cellular apoptosis at the bone-implant interface after four days in the ovine model. Copyright © 2011 Elsevier Masson SAS. All rights reserved.

The growth of glioblastoma orthotopic xenografts in nude mice is directly correlated with impaired object recognition memory.

PubMed

Wasilewska-Sampaio, Ana Paula; Santos, Tiago G; Lopes, Marilene Hohmuth; Cammarota, Martin; Martins, Vilma Regina

2014-01-17

Cognitive dysfunction is found in patients with brain tumors and there is a need to determine whether it can be replicated in an experimental model. In the present study, the object recognition (OR) paradigm was used to investigate cognitive performance in nude mice, which represent one of the most important animal models available to study human tumors in vivo. Mice with orthotopic xenografts of the human U87MG glioblastoma cell line were trained at 9, 14, and 18days (D9, D14, and D18, respectively) after implantation of 5×10(5) cells. At D9, the mice showed normal behavior when tested 90min or 24h after training and compared to control nude mice. Animals at D14 were still able to discriminate between familiar and novel objects, but exhibited a lower performance than animals at D9. Total impairment in the OR memory was observed when animals were evaluated on D18. These alterations were detected earlier than any other clinical symptoms, which were observed only 22-24days after tumor implantation. There was a significant correlation between the discrimination index (d2) and time after tumor implantation as well as between d2 and tumor volume. These data indicate that the OR task is a robust test to identify early behavior alterations caused by glioblastoma in nude mice. In addition, these results suggest that OR task can be a reliable tool to test the efficacy of new therapies against these tumors. © 2013 Elsevier Inc. All rights reserved.

Respiratory epithelial ingrowth and hemorrhage as late complications of orbital floor fracture repair with silicone sheet implant.

PubMed

Jones, David F; Wilson, Matthew W

2008-01-01

The authors present a unique case of rapidly progressive proptosis in a woman 23 years after repair of an orbital floor fracture. Clinical studies, surgical exploration, and pathology revealed a hemorrhagic cyst lined with respiratory epithelium surrounding her previously placed silicone implant.

Microscopic observations of osteoblast growth on micro-arc oxidized β titanium

NASA Astrophysics Data System (ADS)

Chen, Hsien-Te; Chung, Chi-Jen; Yang, Tsai-Ching; Tang, Chin-Hsin; He, Ju-Liang

2013-02-01

Titanium alloys are widely used in orthopedic and dental implants, owing to their excellent physical properties and biocompatibility. By using the micro-arc oxidation (MAO), we generated anatase-rich (A-TiO2) and rutile-rich (R-TiO2) titanium dioxide coatings, individually on β-Ti alloy, in which the latter achieved an enhanced in vitro and in vivo performance. Thoroughly elucidating how the osteoblasts interact with TiO2 coatings is of worthwhile interest. This study adopts the focused ion beam (FIB) to section off the TiO2 coated samples for further scanning electron microscope (SEM) and transmission electron microscope (TEM) observation. The detailed crystal structures of the TiO2 coated specimens are also characterized. Experimental results indicate osteoblasts adhered more tenaciously and grew conformably with more lamellipodia extent on the R-TiO2 specimen than on the A-TiO2 and raw β-Ti specimens. FIB/SEM cross-sectional images of the cell/TiO2 interface revealed micro gaps between the cell membrane and contact surface of A-TiO2 specimen, while it was not found on the R-TiO2 specimen. Additionally, the number of adhered and proliferated cells on the R-TiO2 specimen was visually greater than the others. Closely examining EDS line scans and elemental mappings of the FIB/TEM cross-sectional images of the cell/TiO2 interface reveals both the cell body and interior space of the TiO2 coating contain nitrogen and sulfur (the biological elements in cell). This finding supports the assumption that osteoblast can grow into the porous structure of TiO2 coatings and demonstrating that the R-TiO2 coating formed by MAO serves the best for β-Ti alloys as orthopedic and dental implants.

Pro-inflammatory Analysis of Macrophages in Contact with Titanium Particles and Porphyromonas gingivalis.

PubMed

Dodo, Cindy Goes; Meirelles, Luiz; Aviles-Reyes, Alejandro; Ruiz, Karina Gonzalez Silvério; Abranches, Jacqueline; Cury, Altair Antoninha Del Bel

2017-01-01

During insertion of titanium dental implants, particles may shear from the implant to the periimplant region causing osteolysis, and their association with bacteria can exacerbate the inflammatory reaction. However, the association of a high invasive bacterium from the oral cavity, Porphyromonas gingivalis (Pg), and titanium particles remains unknown. This study evaluated pro-inflammatory reaction of human macrophages in contact with micro and nanoparticles of titanium associated with Porphyromonas gingivalis lipopolysaccharide (PgLPS). THP-1 cell were used and treated for 12, 24 and 48 h following 6 groups: Control(C), PgLPS (L); Microparticles (M); Nanoparticles (N); PgLPS and microparticles (LM); PgLPS and nanoparticles (LN). The following assays were carried out: i) cell viability using MTS, ii) cell morphology by SEM and iii) expression of tumor necrosis factor alpha (TNF-α), interleukin-1 beta (IL-1β) and interleukin-6 (IL-6) by qRT-PCR and ELISA. For statistics two-way ANOVA followed by Tukey's test was used (p<0.05). After treatment, cells presented similar viability and morphology demonstrating that the treatments were not able to induce cell death. Gene expression was significantly higher for TNF-α and IL1-β after 12 h, and for IL-6 after 24 h in the N and LN groups. Cytokine production over time was an ascending curve for TNF-α with the peak at 48 h and IL1-β and IL-6 had a straight line among the time points, although cells from N group presented a significant production of IL-6 at 48 h. In conclusion, these results suggest that titanium nanoparticles stimulate stronger pro-inflammatory response in macrophages, independent of their association with LPS from P.gingivalis.

Implant-Abutment Contact Surfaces and Microgap Measurements of Different Implant Connections Under 3-Dimensional X-Ray Microtomography.

PubMed

Scarano, Antonio; Valbonetti, Luca; Degidi, Marco; Pecci, Raffaella; Piattelli, Adriano; de Oliveira, P S; Perrotti, Vittoria

2016-10-01

The presence of a microgap between implant and abutment could produce a bacterial reservoir which could interfere with the long-term health of the periimplant tissues. The aim of this article was to evaluate, by x-ray 3-dimensional microtomography, implant-abutment contact surfaces and microgaps at the implant-abutment interface in different types of implant-abutment connections. A total of 40 implants were used in this in vitro study. Ten implants presented a screw-retained internal hexagon abutment (group I), 10 had a Morse Cone taper internal connection (group II), 10 another type of Morse Cone taper internal connection (group III), and 10 had a screwed trilobed connection (group IV). In both types of Morse Cone internal connections, there was no detectable separation at the implant-abutment in the area of the conical connection, and there was an absolute congruity without any microgaps between abutment and implant. No line was visible separating the implant and the abutment. On the contrary, in the screwed abutment implants, numerous gaps and voids were present. The results of this study support the hypothesis that different types of implant-abutment joints are responsible for the observed differences in bacterial penetration.

Mitochondrial functionality in female reproduction.

PubMed

Gąsior, Łukasz; Daszkiewicz, Regina; Ogórek, Mateusz; Polański, Zbigniew

2017-01-04

In most animal species female germ cells are the source of mitochondrial genome for the whole body of individuals. As a source of mitochondrial DNA for future generations the mitochondria in the female germ line undergo dynamic quantitative and qualitative changes. In addition to maintaining the intact template of mitochondrial genome from one generation to another, mitochondrial role in oocytes is much more complex and pleiotropic. The quality of mitochondria determines the ability of meiotic divisions, fertilization ability, and activation after fertilization or sustaining development of a new embryo. The presence of normal number of functional mitochondria is also crucial for proper implantation and pregnancy maintaining. This article addresses issues of mitochondrial role and function in mammalian oocyte and presents new approaches in studies of mitochondrial function in female germ cells.

Hip Implant Systems

MedlinePlus

... of metal and the socket is made of plastic (polyethylene) or has a plastic lining. Ceramic-on-Polyethylene: The ball is made of ceramic and the socket is made of plastic (polyethylene) or has a plastic lining. Metal-on- ...

Possible cage motion of interstitial Fe in α-Al 2 O 3

NASA Astrophysics Data System (ADS)

Gunnlaugsson, H. P.; Johnston, K.; Masenda, H.; Mantovan, R.; Mølholt, T. E.; Bharuth-Ram, K.; Gislason, H. P.; Langouche, G.; Madsen, M. B.; Naidoo, D.; Ólafsson, S.; Weyer, G.

2013-04-01

In addition to spectral components due to Fe2 + and Fe3 + , a single line is observed in emission Mössbauer spectra following low fluence (<1015 cm - 2) implantation of 57Fe*, 57Mn and 57Co in α-Al2O3. For the 57Co and 57Mn implantations, the intensity of the single line is found to depend on the emission angle relative to the crystal symmetry axis. This angular dependence can be explained by a non-isotropic f-factor and/or motion of the Fe ion between sites in an interstitial cage. It is argued that interstitial cage motion is a more likely explanation, as this can account for the lack of quadrupole splitting of the line.

Reliability systems for implantable cardiac defibrillator batteries

NASA Astrophysics Data System (ADS)

Takeuchi, Esther S.

The reliability of the power sources used in implantable cardiac defibrillators is critical due to the life-saving nature of the device. Achieving a high reliability power source depends on several systems functioning together. Appropriate cell design is the first step in assuring a reliable product. Qualification of critical components and of the cells using those components is done prior to their designation as implantable grade. Product consistency is assured by control of manufacturing practices and verified by sampling plans using both accelerated and real-time testing. Results to date show that lithium/silver vanadium oxide cells used for implantable cardiac defibrillators have a calculated maximum random failure rate of 0.005% per test month.

Ex vivo bone morphogenetic protein 2 gene delivery using periodontal ligament stem cells for enhanced re-osseointegration in the regenerative treatment of peri-implantitis.

PubMed

Park, Shin-Young; Kim, Kyoung-Hwa; Gwak, Eun-Hye; Rhee, Sang-Hoon; Lee, Jeong-Cheol; Shin, Seung-Yun; Koo, Ki-Tae; Lee, Yong-Moo; Seol, Yang-Jo

2015-01-01

Peri-implantitis is a chronic inflammatory process with advanced bone loss and impaired healing potential. For peri-implantitis treatment, tissue engineering can be applied to enhance bone regeneration of peri-implant defects. This study aimed to evaluate ex vivo bone morphogenetic protein 2 (BMP2) gene delivery using canine periodontal ligament stem cells (PDLSCs) for regeneration of peri-implantitis defects. Canine PDLSCs were transduced with adenoviral vectors containing BMP2 (BMP2/PDLSCs). After peri-implantitis was induced by ligature placement in six beagle dogs, regenerative procedures were performed; hydroxyapatite (HA) particles and collagen gel with autologous canine PDLSCs (PDLSC group) or BMP2/PDLSCs (BMP/PDLSC group) or without cells (control group) were grafted into the defects and covered by an absorbable membrane. Three months later, the animals were sacrificed. In vitro, BMP2/PDLSCs showed similar levels of stem cell properties to PDLSCs, such as colony-forming efficiency and expression of MSC markers STRO-1 and CD 146. BMP2/PDLSCs produced BMP-2 until day 21 at a concentration of 4-8 ng/mL. In vivo, the BMP2/PDLSC group showed significantly more new bone formation and re-osseointegration in peri-implantitis defects compared to the other groups. In conclusion, ex vivo BMP2 gene delivery using PDLSCs enhanced new bone formation and re-osseointegration in peri-implantitis defects. © 2014 Wiley Periodicals, Inc.

Engineered Protein Coatings to Improve the Osseointegration of Dental and Orthopaedic Implants

PubMed Central

Raphel, Jordan; Karlsson, Johan; Galli, Silvia; Wennerberg, Ann; Lindsay, Christopher; Haugh, Matthew; Pajarinen, Jukka; Goodman, Stuart B.; Jimbo, Ryo; Andersson, Martin; Heilshorn, Sarah C.

2016-01-01

Here we present the design of an engineered, elastin-like protein (ELP) that is chemically modified to enable stable coatings on the surfaces of titanium-based dental and orthopaedic implants by novel photocrosslinking and solution processing steps. The ELP includes an extended RGD sequence to confer bio-signaling and an elastin-like sequence for mechanical stability. ELP thin films were fabricated on cp-Ti and Ti6Al4V surfaces using scalable spin and dip coating processes with photoactive covalent crosslinking through a carbene insertion mechanism. The coatings withstood procedures mimicking dental screw and hip replacement stem implantations, a key metric for clinical translation. They promoted rapid adhesion of MG63 osteoblast-like cells, with over 80% adhesion after 24 hours, compared to 38% adhesion on uncoated Ti6Al4V. MG63 cells produced significantly more mineralization on ELP coatings compared to uncoated Ti6Al4V. Human bone marrow mesenchymal stem cells (hMSCs) had an earlier increase in alkaline phosphatase activity, indicating more rapid osteogenic differentiation and mineral deposition on adhesive ELP coatings. Rat tibia and femur in vivo studies demonstrated that cell-adhesive ELP-coated implants increased bone-implant contact area and interfacial strength after one week. These results suggest that ELP coatings withstand surgical implantation and promote rapid osseointegration, enabling earlier implant loading and potentially preventing micromotion that leads to aseptic loosening and premature implant failure. PMID:26790146

Generation of electrical power under human skin by subdermal solar cell arrays for implantable bioelectronic devices.

PubMed

Song, Kwangsun; Han, Jung Hyun; Yang, Hyung Chae; Nam, Kwang Il; Lee, Jongho

2017-06-15

Medical electronic implants can significantly improve people's health and quality of life. These implants are typically powered by batteries, which usually have a finite lifetime and therefore must be replaced periodically using surgical procedures. Recently, subdermal solar cells that can generate electricity by absorbing light transmitted through skin have been proposed as a sustainable electricity source to power medical electronic implants in bodies. However, the results to date have been obtained with animal models. To apply the technology to human beings, electrical performance should be characterized using human skin covering the subdermal solar cells. In this paper, we present electrical performance results (up to 9.05mW/cm 2 ) of the implantable solar cell array under 59 human skin samples isolated from 10 cadavers. The results indicate that the power densities depend on the thickness and tone of the human skin, e.g., higher power was generated under thinner and brighter skin. The generated power density is high enough to operate currently available medical electronic implants such as pacemakers that require tens of microwatt. Copyright © 2016 Elsevier B.V. All rights reserved.

Peripheral white blood cells profile of biodegradable metal implant in mice animal model

NASA Astrophysics Data System (ADS)

Paramitha, Devi; Noviana, Deni; Estuningsih, Sri; Ulum, Mokhamad Fakhrul; Nasution, Ahmad Kafrawi; Hermawan, Hendra

2015-09-01

Biocompatibility or safety of the medical device is considered important. It can be determined by blood profile examination. The aim of this study was to assess the biocompatibility of biodegradable metal implant through peripheral white blood cells (WBCs) profile approach. Forty eight male ddy mice were divided into four groups according to the materials implanted: iron wire (Fe), magnesium rod (Mg), stainless steel surgical wire (SS316L) and control with sham (K). Implants were inserted and attached onto the right femoral bone on latero-medial region. In this study, peripheral white blood cells and leukocyte differentiation were the parameters examined. The result showed that the WBCs value of all groups were decreased at the first day after implantation, increased at the 10th day and continued increasing at the 30th day of observation, except Mg group which has decreased. Neutrophil, as an inflammatory cells, was increased at the early weeks and decreased at the day-30 after surgery in all groups. Despite, these values during the observation were still within the normal range. As a conclus ion, biodegradable metal implants lead to an inflammatory reaction, with no adverse effect on WBC value found.

Peripheral white blood cells profile of biodegradable metal implant in mice animal model

DOE Office of Scientific and Technical Information (OSTI.GOV)

Paramitha, Devi; Noviana, Deni, E-mail: deni@ipb.ac.id; Estuningsih, Sri

Biocompatibility or safety of the medical device is considered important. It can be determined by blood profile examination. The aim of this study was to assess the biocompatibility of biodegradable metal implant through peripheral white blood cells (WBCs) profile approach. Forty eight male ddy mice were divided into four groups according to the materials implanted: iron wire (Fe), magnesium rod (Mg), stainless steel surgical wire (SS316L) and control with sham (K). Implants were inserted and attached onto the right femoral bone on latero-medial region. In this study, peripheral white blood cells and leukocyte differentiation were the parameters examined. The resultmore » showed that the WBCs value of all groups were decreased at the first day after implantation, increased at the 10th day and continued increasing at the 30th day of observation, except Mg group which has decreased. Neutrophil, as an inflammatory cells, was increased at the early weeks and decreased at the day-30 after surgery in all groups. Despite, these values during the observation were still within the normal range. As a conclus ion, biodegradable metal implants lead to an inflammatory reaction, with no adverse effect on WBC value found.« less

Single-cell transcriptome of early embryos and cultured embryonic stem cells of cynomolgus monkeys

PubMed Central

Nakamura, Tomonori; Yabuta, Yukihiro; Okamoto, Ikuhiro; Sasaki, Kotaro; Iwatani, Chizuru; Tsuchiya, Hideaki; Saitou, Mitinori

2017-01-01

In mammals, the development of pluripotency and specification of primordial germ cells (PGCs) have been studied predominantly using mice as a model organism. However, divergences among mammalian species for such processes have begun to be recognized. Between humans and mice, pre-implantation development appears relatively similar, but the manner and morphology of post-implantation development are significantly different. Nevertheless, the embryogenesis just after implantation in primates, including the specification of PGCs, has been unexplored due to the difficulties in analyzing the embryos at relevant developmental stages. Here, we present a comprehensive single-cell transcriptome dataset of pre- and early post-implantation embryo cells, PGCs and embryonic stem cells (ESCs) of cynomolgus monkeys as a model of higher primates. The identities of each transcriptome were also validated rigorously by other way such as immunofluorescent analysis. The information reported here will serve as a foundation for our understanding of a wide range of processes in the developmental biology of primates, including humans. PMID:28649393

Silicon solar cells by ion implantation and pulsed energy processing

NASA Technical Reports Server (NTRS)

Kirkpatrick, A. R.; Minnucci, J. A.; Shaughnessy, T. S.; Greenwald, A. C.

1976-01-01

A new method for fabrication of silicon solar cells is being developed around ion implantation in conjunction with pulsed electron beam techniques to replace conventional furnace processing. Solar cells can be fabricated totally in a vacuum environment at room temperature. Cells with 10% AM0 efficiency have been demonstrated. High efficiency cells and effective automated processing capabilities are anticipated.

Prediction and Measurement of Temperature Fields in Silicon-on-Insulator Electronic Circuits

DTIC Science & Technology

1995-08-01

common dimensions are given in Table 1. Almost all of the device power is dissipated in the channel. The electri- cally insulating implanted layer...data. Region or Component substrate Material SOI implanted insulating layers single-crystal silicon, 3 x 1015 boron atoms cm -3 Thermal... implanted silicon-dioxide layer in SOI wafers. The data for each device for varying powers fall near a line originating at P = 0 and T0 = 303 K

Decidualization and angiogenesis in early pregnancy: unravelling the functions of DC and NK cells.

PubMed

Blois, Sandra M; Klapp, Burghard F; Barrientos, Gabriela

2011-03-01

Differentiation of endometrial stromal cells and formation of new maternal blood vessels at the time of embryo implantation are critical for the establishment and maintenance of gestation. The regulatory functions of decidual leukocytes during early pregnancy, particularly dendritic cells (DC) and NK cells, may be important not only for the generation of maternal immunological tolerance but also in the regulation of stromal cell differentiation and the vascular responses associated with the implantation process. However, the specific contributions of DC and NK cells during implantation are still difficult to dissect mainly due to reciprocal regulatory interactions established between them within the decidualizing microenvironment. The present review article discusses current evidence on the regulatory pathways driving decidualization in mice, suggesting that NK cells promote uterine vascular modifications that assist decidual growth but DC directly control stromal cell proliferation, angiogenesis and the homing and maturation of NK cell precursors in the pregnant uterus. Thus, successful implantation appears to result from an interplay between cellular components of the decidualizing endometrium involving immunoregulatory and pro-angiogenic functions of DC and NK cells. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

Evaluation of egg white ovomucin-based porous scaffold as an implantable biomaterial for tissue engineering.

PubMed

Carpena, Nathaniel T; Abueva, Celine D G; Padalhin, Andrew R; Lee, Byong-Taek

2017-10-01

Studies have shown the technological and functional properties of ovomucin (OVN) in the food-agricultural industry. But research has yet to explore its potential as an implantable biomaterial for tissue engineering and regenerative medicine. In this study we isolated OVN from egg white by isoelectric precipitation and fabricated scaffolds with tunable porosity by utilizing its foaming property. Gelatin a known biocompatible material was introduced to stabilize the foams, wherein different ratios of OVN and gelatin had a significant effect on the degree of porosity, pore size and stability of the formed hydrogels. The porous scaffolds were crosslinked with EDC resulting in stable scaffolds with prolonged degradation. Improved cell proliferation and adhesion of rat bone marrow-derived mesenchymal stem cells were observed for OVN containing scaffolds. Although, scaffolds with 75% OVN showed decrease in cell proliferation for L929 fibroblast type of cells. Further biocompatibility assessment as implant material was determined by subcutaneous implantation in rats of selected scaffold. H&E staining showed reasonable vascularization over time and little evidence of severe fibrosis at the implant site. Persistent polarization of classically activated macrophage was not observed, potentially reducing inflammatory response, and showed increased expression of alternatively activated macrophage cells that is favorable for tissue repair. Analysis of IgE levels in rat serum after implantation indicated minimal and resolvable allergic response to the OVN implants. The results demonstrate OVN as an acceptable implant scaffold that could provide new opportunities as an alternative natural biocompatible and functional biomaterial in various biomedical applications. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 2107-2117, 2017. © 2016 Wiley Periodicals, Inc.

Impact of MLH1 expression on tumor evolution after curative surgical tumor resection in a murine orthotopic xenograft model for human MSI colon cancer.

PubMed

Meunier, Katy; Ferron, Marianne; Calmel, Claire; Fléjou, Jean-François; Pocard, Marc; Praz, Françoise

2017-09-01

Colorectal cancers (CRCs) displaying microsatellite instability (MSI) most often result from MLH1 deficiency. The aim of this study was to assess the impact of MLH1 expression per se on tumor evolution after curative surgical resection using a xenograft tumor model. Transplantable tumors established with the human MLH1-deficient HCT116 cell line and its MLH1-complemented isogenic clone, mlh1-3, were implanted onto the caecum of NOD/SCID mice. Curative surgical resection was performed at day 10 in half of the animals. The HCT116-derived tumors were more voluminous compared to the mlh1-3 ones (P = .001). Lymph node metastases and peritoneal carcinomatosis occurred significantly more often in the group of mice grafted with HCT116 (P = .007 and P = .035, respectively). Mlh1-3-grafted mice did not develop peritoneal carcinomatosis or liver metastasis. After surgical resection, lymph node metastases only arose in the group of mice implanted with HCT116 and the rate of cure was significantly lower than in the mlh1-3 group (P = .047). The murine orthotopic xenograft model based on isogenic human CRC cell lines allowed us to reveal the impact of MLH1 expression on tumor evolution in mice who underwent curative surgical resection and in mice whose tumor was left in situ. Our data indicate that the behavior of MLH1-deficient CRC is not only governed by mutations arising in genes harboring microsatellite repeated sequences but also from their defect in MLH1 as such. © 2017 Wiley Periodicals, Inc.

[A European discussion about stem cells for therapeutic use].

PubMed

Boer, G J

2002-06-29

Stem cells as a source material for growing cellular transplants to repair dysfunctional organs appear to be a new challenge for medical science. Though stem cells are also present in foetal and adult organs, embryonic stem cells from the pre-implantation embryo in particular have the potency to proliferate easily in vitro and the capacity to differentiate into all the body's organ-specific cells. Therefore, these are the ideal cells for developing new cell transplantation therapies for diseases such as Parkinson's disease, diabetes mellitus and heart failure. The use of spare in vitro fertilization (IVF) embryos or pre-implantation embryos specially created to harvest human embryonic stem cells is, however, controversial and an ethical problem. In a European discussion platform organised by the European Commission Research Directorate-General, the status quo of the progress was presented and subsequently commented upon and discussed in terms of medical-ethical, social, industrial and patient interests. The expectations of this new medical technology were high, but clinical trials seem only acceptable once the in vitro differentiation of stem cells can be adequately controlled and once it is known how in vitro prepared stem cells behave after implantation. The ethical justification of the use of in vitro pre-implantation embryos remains controversial. The prevailing view is that the interests of severely ill patients for whom no adequate therapy exists, surmounts the interest of protection of a human in vitro pre-implantation embryo, regardless of whether it was the result of IVF or of transplantation of a somatic cell nucleus of the patient in an enucleated donor egg cell (therapeutic cloning).

Effect of electric and magnetic fields near an HVDC converter terminal on implanted cardiac pacemakers. Final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Frazier, M.J.

1980-08-01

The electromagnetic fields associated with HVDC converters and transmission lines constitute a unique environment for persons with implanted cardiac pacemakers. A measurement program has been conducted to assess the potential interfering effects of these harmonically rich fields on implanted pacemakers. The experimental procedures that were employed take into account the combined effects of the electric and magnetic fields. The effect of the resulting body current on the response of six pacemakers was assessed in the laboratory, using a previously developed model to relate body current to pacemaker pickup voltage. The results show that R-wave pacemaker reversion can be expected atmore » some locations within the converter facility, but that a large safety margin for unperturbed pacemaker operation exists beneath the transmission lines.« less

Controlled implant/soft tissue interaction by nanoscale surface modifications of 3D porous titanium implants.

PubMed

Rieger, Elisabeth; Dupret-Bories, Agnès; Salou, Laetitia; Metz-Boutigue, Marie-Helene; Layrolle, Pierre; Debry, Christian; Lavalle, Philippe; Vrana, Nihal Engin

2015-06-07

Porous titanium implants are widely employed in the orthopaedics field to ensure good bone fixation. Recently, the use of porous titanium implants has also been investigated in artificial larynx development in a clinical setting. Such uses necessitate a better understanding of the interaction of soft tissues with porous titanium structures. Moreover, surface treatments of titanium have been generally evaluated in planar structures, while the porous titanium implants have complex 3 dimensional (3D) architectures. In this study, the determining factors for soft tissue integration of 3D porous titanium implants were investigated as a function of surface treatments via quantification of the interaction of serum proteins and cells with single titanium microbeads (300-500 μm in diameter). Samples were either acid etched or nanostructured by anodization. When the samples are used in 3D configuration (porous titanium discs of 2 mm thickness) in vivo (in subcutis of rats for 2 weeks), a better integration was observed for both anodized and acid etched samples compared to the non-treated implants. If the implants were also pre-treated with rat serum before implantation, the integration was further facilitated. In order to understand the underlying reasons for this effect, human fibroblast cell culture tests under several conditions (directly on beads, beads in suspension, beads encapsulated in gelatin hydrogels) were conducted to mimic the different interactions of cells with Ti implants in vivo. Physical characterization showed that surface treatments increased hydrophilicity, protein adsorption and roughness. Surface treatments also resulted in improved adsorption of serum albumin which in turn facilitated the adsorption of other proteins such as apolipoprotein as quantified by protein sequencing. The cellular response to the beads showed considerable difference with respect to the cell culture configuration. When the titanium microbeads were entrapped in cell-laden gelatin hydrogels, significantly more cells migrated towards the acid etched beads. In conclusion, the nanoscale surface treatment of 3D porous titanium structures can modulate in vivo integration by the accumulative effect of the surface treatment on several physical factors such as protein adsorption, surface hydrophilicity and surface roughness. The improved protein adsorption capacity of the treated implants can be further exploited by a pre-treatment with autologous serum to render the implant surface more bioactive. Titanium microbeads are a good model system to observe these effects in a 3D microenvironment and provide a better representation of cellular responses in 3D.

Influence of cell loss after vitrification or slow-freezing on further in vitro development and implantation of human Day 3 embryos.

PubMed

Van Landuyt, L; Van de Velde, H; De Vos, A; Haentjens, P; Blockeel, C; Tournaye, H; Verheyen, G

2013-11-01

Is the effect of cell loss on further cleavage and implantation different for vitrified than for slowly frozen Day 3 embryos? Vitrified embryos develop better overnight than slowly frozen embryos, regardless of the number of cells lost, but have similar implantation potential if further cleavage occurs overnight. After slow-freezing, similar implantation rates have been obtained for intact 4-cell embryos or 4-cell embryos with 1 cell damaged. For slowly frozen Day 3 embryos, lower implantation rates have been observed when at least 25% of cells were lost. Other studies reported similar implantation potential for 7- to 8-cell embryos with 0, 1 or 2 cells damaged. No data are available on further development of vitrified embryos in relation to cell damage. Survival and overnight cleavage were retrospectively assessed for 7664 slowly frozen Day 3 embryos (study period: January 2004-December 2008) and 1827 vitrified embryos (study period: April 2010-September 2011). Overnight cleavage was assessed according to cell stage at cryopreservation and post-thaw cell loss for both protocols. The relationship between cell loss and implantation rate was analysed in a subgroup of single-embryo transfers (SETs) with 780 slowly frozen and 294 vitrified embryos. Embryos with ≥6 blastomeres and ≤20% fragmentation were cryopreserved using slow controlled freezing [with dimethyl sulphoxide (DMSO) as cryoprotectant] or closed vitrification [with DMSO-ethylene glycol (EG)-sucrose (S) as cryoprotectants]. Only embryos with ≥50% of cells intact after thawing were cultured overnight and were only transferred if further cleaved. For each outcome, logistic regression analysis was performed. Survival was 94 and 64% after vitrification and slow-freezing respectively. Logistic regression analysis showed that overnight cleavage of surviving embryos was higher after vitrification than after slow-freezing (P < 0.001) and decreased according to the degree of cell damage (P < 0.001). If the embryo continued to cleave after thawing, there was no effect of the number of cells lost or the cryopreservation method on its implantation potential. The implantation rates of embryos with 0, 1 or 2 cells damaged were, respectively, 21% (n = 114), 21% (n = 28) and 20% (n = 12) after slow-freezing and 20% (n = 50), 21% (n = 5) and 27% (n = 4) after vitrification. This analysis is retrospective and study periods for vitrification and slow-freezing are different. The number of SETs with vitrified embryos is limited. However, a large number of vitrified embryos were available to analyse the further cleavage of surviving embryos. Although it is not proved that vitrified embryos are more viable than slowly frozen embryos in terms of pregnancy outcome, vitrification yields higher survival rates, better overnight development and higher transfer rates per embryo warmed. This increases the number of frozen transfer cycles originating from a single treatment and might result in a better cumulative clinical outcome. Based on the present data, the policy to warm an extra embryo before overnight culture depends on the cell stage at cryopreservation and the cell damage after warming. For 8-cell embryos, up to two cells may be damaged compared with only one cell for 6- to 7-cell embryos, before an additional embryo is warmed. none.

Anti-PD-1 Blockade and Stereotactic Radiation Produce Long-Term Survival in Mice With Intracranial Gliomas

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zeng, Jing; See, Alfred P.; Phallen, Jillian

2013-06-01

Purpose: Glioblastoma multiforme (GBM) is the most common primary brain tumor in adults, and radiation is one of the main treatment modalities. However, cure rates remain low despite best available therapies. Immunotherapy is a promising modality that could work synergistically with radiation, which has been shown to increase antigen presentation and promote a proinflammatory tumor microenvironment. Programmed-death-1 (PD-1) is a surface receptor expressed on activated and exhausted T cells, which mediate T cell inhibition upon binding with its ligand PD-L1, expressed on many tumor types including human GBMs. We tested the combination of anti-PD-1 immunotherapy with stereotactic radiosurgery in amore » mouse orthotopic GBM model. Methods and Materials: We performed intracranial implantation of mouse glioma cell line GL261 transfected with luciferase into C57BL/6 mice. Mice were stratified into 4 treatment groups: (1) control; (2) radiation only; (3) anti-PD-1 antibody only; and (4) radiation plus anti-PD-1 antibody. Overall survival was quantified. The mice were killed on day 21 after implantation to assess immunologic parameters in the brain/tumor, cervical lymph nodes, and spleen. Results: Improved survival was demonstrated with combination anti-PD-1 therapy plus radiation compared with either modality alone: median survival was 25 days in the control arm, 27 days in the anti-PD-1 antibody arm, 28 days in the radiation arm, and 53 days in the radiation plus anti-PD-1 therapy arm (P<.05 by log-rank Mantle-Cox). Long-term survival was seen only in the combined treatment arm, with a fraction (15%-40%) of animals alive at day 180+ after treatment. Immunologic data on day 21 after implantation showed increased tumor infiltration by cytotoxic T cells (CD8+/interferon-γ+/tumor necrosis factor-α+) and decreased regulatory T cells (CD4+/FOXP3) in the combined treatment group compared with the single modality arms. Conclusions: The combination of PD-1 blockade and localized radiation therapy results in long-term survival in mice with orthotopic brain tumors. These studies provide strong preclinical evidence to support combination trials in patients with GBM.« less

Enhanced osseointegration of titanium implants in a rat model of osteoporosis using multilayer bone mesenchymal stem cell sheets

PubMed Central

Duan, Yan; Ma, Wei; Li, Dehua; Wang, Tongfei; Liu, Baolin

2017-01-01

The present study aimed to investigate whether bone marrow-derived mesenchymal stem cell (BMSC) sheets combined with titanium implants enhanced implant osseointegration in an ovariectomized (OVX) rat model of osteoporosis. Sprague-Dawley rats were randomly assigned into a test group and control group. Allogenic BMSCs were collected from the rats, cultured and stored via cryopreservation. At 6 months post-ovariectomy, establishment of the OVX model was confirmed by micro-computed tomography (CT) measurements. BMSC sheets were subsequently layered and wrapped over titanium implants for implantation. Unmodified implants served as the control. At 8 weeks post-implantation, samples were observed by micro-CT reconstruction and histomorphometric evaluation. Micro-CT reconstruction identified a marked improvement in the surrounding bone volume following treatment, with data analyses indicating a significant increase in bone volume in the BMSC-implant group compared with the control implant group (P<0.05). In addition, histological staining identified new bone formation and an increased rate of bone-implant contact surrounding the BMSC-implant constructs. These results indicate that the use of BMSC sheets as a novel tissue engineering approach improves the osseointegration of titanium implants in an osteoporosis model. This method may expand the operative indications in patients with osteoporosis and improve the success rate of clinical dental implant treatments. PMID:29250137

Gene expression profiling of macrophages: implications for an immunosuppressive effect of dissolucytotic gold ions

PubMed Central

2012-01-01

Background Gold salts has previously been used in the treatment of rheumatoid arthritis but have been replaced by biologicals such as TNF-α inhibitors. The mechanisms behind the anti-inflammatory effect of metallic gold ions are still unknown, however, recent data showed that charged gold atoms are released from pure metallic gold implants by macrophages via a dissolucytosis membrane, and that gold ions are taken up by local macrophages, mast cells and to some extent fibroblasts. These findings open the question of possible immunomodulatory effects of metallic gold and motivate efforts on a deeper understanding of the effect of metallic gold on key inflammatory cells as macrophages. Methods Human macrophage cells (cell line THP-1) were grown on gold foils and intracellular uptake was analysed by autometallography. The impact of phagocytised gold ions on viability of THP-1 cells was investigated by trypan blue staining and TUNEL assay. The global gene expression profile of THP-1 cells after incorporation of gold ions was studied using microarray analysis comprising approximately 20,000 genes. The gene expression data was confirmed by measurement of secreted proteins. Results Autometallography showed intracellular uptake of gold ions into THP-1 cells. No significant effect on viability of THP-1 cells was demonstrated. Our data revealed a unique gene expression signature of dissolucytotic THP-1 cells that had taken up gold ions. A large number of regulated genes were functionally related to immunomodulation. Gold ion uptake induced downregulation of genes involved in rheumatoid arthritis such as hepatocyte growth factor, tenascin-C, inhibitor of DNA binding 1 and 3 and matrix metalloproteinase 13. Conclusion The data obtained in this study offer new insights into the mode of action of gold ions and suggest for the investigation of effects on other key cells and a possible future role of metallic gold as implants in rheumatoid arthritis or other inflammatory conditions. PMID:23140489

CDDO-Me inhibits tumor growth and prevents recurrence of pancreatic ductal adenocarcinoma.

PubMed

Gao, Xiaohua; Deeb, Dorrah; Liu, Yongbo; Liu, Patricia; Zhang, Yiguan; Shaw, Jiajiu; Gautam, Subhash C

2015-12-01

Methyl-2-cyano-3,12-dioxooleana-1,9(11)-dien-28-oate (CDDO-Me) has shown potent antitumorigenic activity against a wide range of cancer cell lines in vitro and inhibited the growth of liver, lung and prostate cancer in vivo. In the present study, we examined the antitumor activity of CDDO-Me for pancreatic ductal adenocarcinoma (PDAC) cells with and without activating K-ras mutations. Treatment of K-ras mutant MiaPaCa-2 and K-ras normal BxPC-3 cells with CDDO-Me elicited strong antiproliferative and proapoptopic responses in both cell lines in culture. The inhibition of cell proliferation and induction of apoptosis was accompanied by the inhibition of antiapoptotic/prosurvival p-Akt, NF-кB and p-mTOR signaling proteins. For testing efficacy of CDDO-Me in vivo heterotopic and orthotopic xenografts were generated by implanting BxPC-3 and MiaPaCa-2 cells subcutaneously and in the pancreatic tail, respectively. Treatment with CDDO-Me significantly inhibited the growth of BxPC-3 xenografts and reduced the levels of p-Akt and p-mTOR in tumor tissue. In mice with orthotopic MiaPaCa-2 xenografts, treatment with CDDO-Me prolonged the survival of mice when administered following the surgical resection of tumors. The latter was attributed to the eradication of residual PDAC remaining after resection of tumors. These preclinical data demonstrate the potential of CDDO-Me for treating primary PDAC tumors and for preventing relapse/recurrence through the destruction of residual disease.

Elucidation of Iron Gettering Mechanisms in Boron-Implanted Silicon Solar Cells

DOE PAGES

Laine, Hannu S.; Vahanissi, Ville; Liu, Zhengjun; ...

2017-12-15

To facilitate cost-effective manufacturing of boron-implanted silicon solar cells as an alternative to BBr 3 diffusion, we performed a quantitative test of the gettering induced by solar-typical boron-implants with the potential for low saturation current density emitters (< 50 fA/cm 2). We show that depending on the contamination level and the gettering anneal chosen, such boron-implanted emitters can induce more than a 99.9% reduction in bulk iron point defect concentration. The iron point defect results as well as synchrotron-based Nano-X-ray-fluorescence investigations of iron precipitates formed in the implanted layer imply that, with the chosen experimental parameters, iron precipitation is themore » dominant gettering mechanism, with segregation-based gettering playing a smaller role. We reproduce the measured iron point defect and precipitate distributions via kinetics modeling. First, we simulate the structural defect distribution created by the implantation process, and then we model these structural defects as heterogeneous precipitation sites for iron. Unlike previous theoretical work on gettering via boron- or phosphorus-implantation, our model is free of adjustable simulation parameters. The close agreement between the model and experimental results indicates that the model successfully captures the necessary physics to describe the iron gettering mechanisms operating in boron-implanted silicon. Furthermore, this modeling capability allows high-performance, cost-effective implanted silicon solar cells to be designed.« less

Cochlear implants and ex vivo BDNF gene therapy protect spiral ganglion neurons.

PubMed

Rejali, Darius; Lee, Valerie A; Abrashkin, Karen A; Humayun, Nousheen; Swiderski, Donald L; Raphael, Yehoash

2007-06-01

Spiral ganglion neurons often degenerate in the deaf ear, compromising the function of cochlear implants. Cochlear implant function can be improved by good preservation of the spiral ganglion neurons, which are the target of electrical stimulation by the implant. Brain derived neurotrophic factor (BDNF) has previously been shown to enhance spiral ganglion survival in experimentally deafened ears. Providing enhanced levels of BDNF in human ears may be accomplished by one of several different methods. The goal of these experiments was to test a modified design of the cochlear implant electrode that includes a coating of fibroblast cells transduced by a viral vector with a BDNF gene insert. To accomplish this type of ex vivo gene transfer, we transduced guinea pig fibroblasts with an adenovirus with a BDNF gene cassette insert, and determined that these cells secreted BDNF. We then attached BDNF-secreting cells to the cochlear implant electrode via an agarose gel, and implanted the electrode in the scala tympani. We determined that the BDNF expressing electrodes were able to preserve significantly more spiral ganglion neurons in the basal turns of the cochlea after 48 days of implantation when compared to control electrodes. This protective effect decreased in the higher cochlear turns. The data demonstrate the feasibility of combining cochlear implant therapy with ex vivo gene transfer for enhancing spiral ganglion neuron survival.

Elucidation of Iron Gettering Mechanisms in Boron-Implanted Silicon Solar Cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Laine, Hannu S.; Vahanissi, Ville; Liu, Zhengjun

To facilitate cost-effective manufacturing of boron-implanted silicon solar cells as an alternative to BBr 3 diffusion, we performed a quantitative test of the gettering induced by solar-typical boron-implants with the potential for low saturation current density emitters (< 50 fA/cm 2). We show that depending on the contamination level and the gettering anneal chosen, such boron-implanted emitters can induce more than a 99.9% reduction in bulk iron point defect concentration. The iron point defect results as well as synchrotron-based Nano-X-ray-fluorescence investigations of iron precipitates formed in the implanted layer imply that, with the chosen experimental parameters, iron precipitation is themore » dominant gettering mechanism, with segregation-based gettering playing a smaller role. We reproduce the measured iron point defect and precipitate distributions via kinetics modeling. First, we simulate the structural defect distribution created by the implantation process, and then we model these structural defects as heterogeneous precipitation sites for iron. Unlike previous theoretical work on gettering via boron- or phosphorus-implantation, our model is free of adjustable simulation parameters. The close agreement between the model and experimental results indicates that the model successfully captures the necessary physics to describe the iron gettering mechanisms operating in boron-implanted silicon. Furthermore, this modeling capability allows high-performance, cost-effective implanted silicon solar cells to be designed.« less

Functionalized Antimicrobial Composite Thin Films Printing for Stainless Steel Implant Coatings.

PubMed

Floroian, Laura; Ristoscu, Carmen; Mihailescu, Natalia; Negut, Irina; Badea, Mihaela; Ursutiu, Doru; Chifiriuc, Mariana Carmen; Urzica, Iuliana; Dyia, Hussien Mohammed; Bleotu, Coralia; Mihailescu, Ion N

2016-06-09

In this work we try to address the large interest existing nowadays in the better understanding of the interaction between microbial biofilms and metallic implants. Our aimed was to identify a new preventive strategy to control drug release, biofilm formation and contamination of medical devices with microbes. The transfer and printing of novel bioactive glass-polymer-antibiotic composites by Matrix-Assisted Pulsed Laser Evaporation into uniform thin films onto 316 L stainless steel substrates of the type used in implants are reported. The targets were prepared by freezing in liquid nitrogen mixtures containing polymer and antibiotic reinforced with bioglass powder. The cryogenic targets were submitted to multipulse evaporation by irradiation with an UV KrF* (λ = 248 nm, τFWHM ≤ 25 ns) excimer laser source. The prepared structures were analyzed by infrared spectroscopy, scanning electron microscopy, energy dispersive X-ray spectroscopy and profilometry, before and after immersion in physiological fluids. The bioactivity and the release of the antibiotic have been evaluated. We showed that the incorporated antibiotic underwent a gradually dissolution in physiological fluids thus supporting a high local treatment efficiency. Electrochemical measurements including linear sweep voltammetry and impedance spectroscopy studies were carried out to investigate the corrosion resistance of the coatings in physiological environments. The in vitro biocompatibility assay using the MG63 mammalian cell line revealed that the obtained nanostructured composite films are non-cytotoxic. The antimicrobial effect of the coatings was tested against Staphylococcus aureus and Escherichia coli strains, usually present in implant-associated infections. An anti-biofilm activity was evidenced, stronger against E. coli than the S. aureus strain. The results proved that the applied method allows for the fabrication of implantable biomaterials which shield metal ion release and possess increased biocompatibility and resistance to microbial colonization and biofilm growth.

Evaluation of functionality and biological response of the multilayer flow modulator in porcine animal models.

PubMed

Sultan, Sherif; Kavanagh, Edel P; Hynes, Niamh; Diethrich, Edward B

2016-02-01

This study outlines the use of non-aneurysmal porcine animal models to study device functionality and biological response of the Multilayer Flow Modulator (MFM) (Cardiatis, Isnes, Belgium), with an emphasis on preclinical device functionality and biological response characteristics in an otherwise healthy aorta. Twelve animals were implanted with the study device in the abdominal aorta, in 6 animals for 1 month and 6 animals for 6 months. Upon completion of the study period, each animal underwent a necropsy to examine how the implanted device had affected the artery and surrounding tissue. Neointima and stenosis formation were recorded via morphometry, and endothelialization via histopathological analysis. The MFM devices were delivered to their respective implantation sites without difficulty. Six of the implanted stents were oversized with percentages ranging from 2.6% to 18.8%. Statistical analysis was carried out and showed no significance between the regular sized stent group and oversized stent group for neointimal area (P=0.17), neointimal thickness (P=0.17), and percentage area stenosis (P=0.65). Histopathological findings showed in most areas flattened endothelium like cells lined the luminal surface of the neointima. Scanning electron microscopy also showed the devices were well tolerated, inciting only a minimal neointimal covering and little fibrin or platelet deposition. Neointimal thickness of 239.7±55.6 μm and 318.3±130.4 μm, and percentage area stenosis of 9.6±2.6% and 12.6±5% were recorded at 1 and 6 months respectively. No statistical differences were found between these results. The MFM devices were delivered to their respective implantation sites without difficulty and incited little neointimal and stenosis formation in the aorta, affirming its functionality and biocompatibility.

Augmented cartilage regeneration by implantation of cellular versus acellular implants after bone marrow stimulation: a systematic review and meta-analysis of animal studies.

PubMed

Pot, Michiel W; van Kuppevelt, Toin H; Gonzales, Veronica K; Buma, Pieter; IntHout, Joanna; de Vries, Rob B M; Daamen, Willeke F

2017-01-01

Bone marrow stimulation may be applied to regenerate focal cartilage defects, but generally results in transient clinical improvement and formation of fibrocartilage rather than hyaline cartilage. Tissue engineering and regenerative medicine strive to develop new solutions to regenerate hyaline cartilage tissue. This systematic review and meta-analysis provides a comprehensive overview of current literature and assesses the efficacy of articular cartilage regeneration by implantation of cell-laden versus cell-free biomaterials in the knee and ankle joint in animals after bone marrow stimulation. PubMed and EMBASE (via OvidSP) were systematically searched using tissue engineering, cartilage and animals search strategies. Included were primary studies in which cellular and acellular biomaterials were implanted after applying bone marrow stimulation in the knee or ankle joint in healthy animals. Study characteristics were tabulated and outcome data were collected for meta-analysis for studies applying semi-quantitative histology as outcome measure (117 studies). Cartilage regeneration was expressed on an absolute 0-100% scale and random effects meta-analyses were performed. Implantation of cellular biomaterials significantly improved cartilage regeneration by 18.6% compared to acellular biomaterials. No significant differences were found between biomaterials loaded with stem cells and those loaded with somatic cells. Culture conditions of cells did not affect cartilage regeneration. Cartilage formation was reduced with adipose-derived stem cells compared to other cell types, but still improved compared to acellular scaffolds. Assessment of the risk of bias was impaired due to incomplete reporting for most studies. Implantation of cellular biomaterials improves cartilage regeneration compared to acellular biomaterials.

Smooth muscle cells improve endothelial cell retention on polytetrafluoroethylene grafts in vivo.

PubMed

Yu, Hong; Dai, Wangde; Yang, Zhe; Kirkman, Paul; Weaver, Fred A; Eton, Darwin; Rowe, Vincent L

2003-09-01

We investigated the influence of smooth muscle cells (SMC) on endothelial cell (EC) retention on polytetrafluoroethylene (PTFE) grafts and the effect of SMC seeding on intimal hyperplasia in vivo in a rabbit model. Fibronectin-coated PTFE grafts (4 mm diameter) were seeded with either EC alone, SMC alone, or SMC followed 24 hours later by EC. The grafts were connected to an extracorporal aortic shunt for 1 hour or were individually implanted for 1, 30, and 100 days into the infrarenal aorta as an end-to-side bypass graft. The number of retained cells was compared at 1 hour and at 1 day after implantation. Neointimal thickness was measured 30 and 100 days after implantation. After 1-hour exposure to blood flow, EC retention rate was greater (P <.005) if seeded on top of SMC (98% +/- 2%; n = 8) versus being seeded alone (65 +/- 11%; n = 8). SMC retention rate was 95 +/- 5% (n = 8) when seeded alone. Similar cell retention was obtained 1 day after implantation. After 30-day implantation the neointima was thicker in grafts seeded with EC and SMC (282 +/- 136 microm; n = 3) than with EC only (52 +/- 45 microm; n = 3; P <.001). However, the neointimal thickness for dual-cell-seeded grafts (126 +/- 60 microm; n = 3) was not significantly different (P =.09) from EC-seeded grafts (79 +/- 48 microm; n = 3) after 100-day implantation. EC retention on PTFE grafts in vivo is improved if seeded over a layer of SMC. Further studies are needed to determine whether overlying EC modulate proliferation of underlying SMC.

Long-term erythropoietin gene expression from transduced cells in bioisolator devices.

PubMed

Yanay, Ofer; Barry, Simon C; Flint, Lisa Y; Brzezinski, Margaret; Barton, Randall W; Osborne, William R A

2003-11-20

Recombinant erythropoietin (EPO) is widely administered for long-term treatment of anemia associated with renal failure and other chronic diseases. The ability to deliver EPO by gene therapy would have clinical and economic benefit. We compared autologous and allogeneic transduced primary vascular smooth muscle cells for their ability to provide sustained EPO gene expression when encapsulated in TheraCyte devices implanted subcutaneously (SQ) or intraperitoneally (IP) in rats. Cells were transduced with retrovirus vector LrEpSN encoding rat EPO cDNA. Rats that received either autologous or allogeneic transduced cells showed elevated hematocrits (HCTs) ranging from 50 to 79% that were sustained for more than 12 months. The HCT of control rats remained at baseline (45.8%). Rats that received second SQ implants of either autologous or allogeneic cells showed elevations in hematocrit that were sustained for up to 12 months, suggesting the absence of immunological responses to transduced cells or implant material. All experimental groups had statistically significant elevated HCT (p < 0.001) when compared with controls. Both SQ and IP implantation were equally effective in delivering EPO long term. There were no significant differences in white blood cell (WBC) or platelet (PLT) values between treated and control animals. Implantation of TheraCyte devices was well tolerated and histological evaluation of the devices up to 12 months after surgery revealed a high degree of vascularization and no evidence of host immune response. TheraCyte devices offer a simple and safe gene delivery system that provides sustained therapeutic gene expression, permit removal and implantation of new devices, and do not require immunosuppression of the host.

[Establishment of lymph node metastasis of MDA-MB-231 breast cancer model in nude mice].

PubMed

Wang, Le; Mi, Chengrong; Wang, Wen

2015-06-16

To establish lymph node metastasis of breast cancer model in nude mices using MDA-MB-231 cell lines or tumor masses. Divided twelve female nude mices of five weeks into A, B groups randomly. A group had seven nude mices, B group had five nude mices. A group nude mices were injected with MDA-MB-231 cells suspension into the second right mammary fat pad. Two weeks after emerged tumors, the orthotopic tumors of two nude mices of A group were dissected and then implanted into the second right mammary fat pad of B group nude mices. The other mices of A group continued to be fed. After six weeks of inoculation, we excised the tumors and the swollen lymph nodes in right axilla of all nude mices to make pathological examination. ① A group have a 7/7 tumor formation rate 7 days after implanted, B group was 5/5 5 days after implanted. ② The tumor volumes between the two groups had evident difference (P = 0.023), and the tumor volume of B group was bigger than A group. ③ A group had three nude mices which had one tumid lymph node respectively, the lymph node enlargement rate was 3/5; B group only had one nude mice that had one tumid lymph node, the lymph node enlargement rate was 1/5, the lymph node enlargement rate between the two groups showed no significant difference (P = 0.524). ④ The result of pathology in the two groups testified the tumors were invasive ductal carcinoma. The swollen lymph nodes in A group were reactive hyperplasia lymph nodes; the swollen lymph nodes in B group was metastatic lymph node. The method of orthotopic implantation with MDA-MB-231 tumor mass to establish lymph node metastasis of breast cancer model in nude mice, can provide a useful mean to research the lymph node metastasis mechanism of breast cancer.

Development and fabrication of a solar cell junction processing system

NASA Technical Reports Server (NTRS)

1984-01-01

A processing system capable of producing solar cell junctions by ion implantation followed by pulsed electron beam annealing was developed and constructed. The machine was to be capable of processing 4-inch diameter single-crystal wafers at a rate of 10(7) wafers per year. A microcomputer-controlled pulsed electron beam annealer with a vacuum interlocked wafer transport system was designed, built and demonstrated to produce solar cell junctions on 4-inch wafers with an AMI efficiency of 12%. Experiments showed that a non-mass-analyzed (NMA) ion beam could implant 10 keV phosphorous dopant to form solar cell junctions which were equivalent to mass-analyzed implants. A NMA ion implanter, compatible with the pulsed electron beam annealer and wafer transport system was designed in detail but was not built because of program termination.

Growth promoting in vitro effect of synthetic cyclic RGD-peptides on human osteoblast-like cells attached to cancellous bone.

PubMed

Magdolen, Ursula; Auernheimer, Jörg; Dahmen, Claudia; Schauwecker, Johannes; Gollwitzer, Hans; Tübel, Jutta; Gradinger, Reiner; Kessler, Horst; Schmitt, Manfred; Diehl, Peter

2006-06-01

In tissue engineering, the application of biofunctional compounds on biomaterials such as integrin binding RGD-peptides has gained growing interest. Anchorage-dependent cells like osteoblasts bind to these peptides thus ameliorating the integration of a synthetic implant. In case sterilized bone grafts are used as substitutes for reconstruction of bone defects, the ingrowth of the implanted bone is often disturbed because of severe pretreatment such as irradiation or autoclaving, impairing the biological and mechanical properties of the bone. We report for the first time on the in vitro coating of the surface of freshly resected, cleaned bone discs with synthetic, cyclic RGD-peptides. For this approach, two different RGD-peptides were used, one containing two phosphonate anchors, the other peptide four of these binding moieties to allow efficient association of these reactive RGD-peptides to the inorganic bone matrix. Human osteoblast-like cells were cultured on RGD-coated bone discs and the adherence and growth of the cells were analyzed. Coating of bone discs with RGD-peptides did not improve the adhesion rate of osteoblast-like cells to the discs but significantly (up to 40%) accelerated growth of these cells within 8 days after attachment. This effect points to pretreatment of bone implants, especially at the critical interface area between the implanted bone and the non-resected residual bone structure, before re-implantation in order to stimulate and enhance osteointegration of a bone implant.

Nanotopographical control of human osteoprogenitor differentiation.

PubMed

Dalby, Matthew J; Gadegaard, Nikolaj; Curtis, Adam S G; Oreffo, Richard O C

2007-05-01

Current load-bearing orthopaedic implants are produced in 'bio-inert' materials such as titanium alloys. When inserted into the reamed bone during hip or knee replacement surgery the implants interact with mesenchymal populations including the bone marrow. Bio-inert materials are shielded from the body by differentiation of the cells along the fibroblastic lineage producing scar tissue and inferior healing. This is exacerbated by implant micromotion, which can lead to capsule formation. Thus, next-generation implant materials will have to elicit influence over osteoprogenitor differentiation and mesenchymal populations in order to recruit osteoblastic cells and produce direct bone apposition onto the implant. A powerful method of delivering cues to cells is via topography. Micro-scale topography has been shown to affect cell adhesion, migration, cytoskeleton, proliferation and differentiation of a large range of cell types (thus far all cell types tested have been shown to be responsive to topographical cues). More recent research with nanotopography has also shown a broad range of cell response, with fibroblastic cells sensing down to 10 nm in height. Initial studies with human mesenchymal populations and osteoprogenitor populations have again shown strong cell responses to nanofeatures with increased levels of osteocalcin and osteopontin production from the cells on certain topographies. This is indicative of increased osteoblastic activity on the nanotextured materials. Looking at preliminary data, it is tempting to speculate that progenitor cells are, in fact, more responsive to topography than more mature cell types and that they are actively seeking cues from their environment. This review will investigate the range of nanotopographies available to researchers and our present understanding of mechanisms of progenitor cell response. Finally, it will make some speculations of the future of nanomaterials and progenitor cells in tissue engineering.

Distribution of bacterial morphotypes around natural teeth and titanium implants ad modum Brånemark.

PubMed

Quirynen, M; Listgarten, M A

1990-12-01

The subgingival plaque around both teeth and implants was analysed by means of differential phase-contrast microscopy. It was noted that, in comparison to natural teeth, the subgingival samples from implants were more frequently too small to provide adequate bacterial counts. In 24 partially edentulous patients (with implants and teeth in the same jaw), no significant differences in the distribution of bacterial morphotypes could be found between implants and natural teeth. The %s of coccoid cells, motile rods, spirochetes and other bacteria were 65.8, 2.3, 2.1, and 29.8 for implants and 55.6, 4.9, 3.6, and 34.9 for teeth, respectively. However, when the plaque composition on the implants of fully edentulous patients was compared with those of teeth or implants of partially edentulous patients (with teeth and implants in the same and/or opposite jaw), significant differences appeared. In fully edentulous patients, more coccoid cells (71.3%) and significant fewer motile rods (0.4%) and spirochetes (0.0) were found around the implants. The results suggest that teeth may serve as a reservoir for the bacterial colonisation of titanium implants in the same mouth.

Breast Implant-Associated Anaplastic Large Cell Lymphoma in Australia and New Zealand: High-Surface-Area Textured Implants Are Associated with Increased Risk.

PubMed

Loch-Wilkinson, Anna; Beath, Kenneth J; Knight, Robert John William; Wessels, William Louis Fick; Magnusson, Mark; Papadopoulos, Tim; Connell, Tony; Lofts, Julian; Locke, Michelle; Hopper, Ingrid; Cooter, Rodney; Vickery, Karen; Joshi, Preeti Avinash; Prince, H Miles; Deva, Anand K

2017-10-01

The association between breast implants and breast implant-associated anaplastic large cell lymphoma (ALCL) has been confirmed. Implant-related risk has been difficult to estimate to date due to incomplete datasets. All cases in Australia and New Zealand were identified and analyzed. Textured implants reported in this group were subjected to surface area analysis. Sales data from three leading breast implant manufacturers (i.e., Mentor, Allergan, and Silimed) dating back to 1999 were secured to estimate implant-specific risk. Fifty-five cases of breast implant-associated ALCL were diagnosed in Australia and New Zealand between 2007 and 2016. The mean age of patients was 47.1 years and the mean time of implant exposure was 7.46 years. There were four deaths in the series related to mass and/or metastatic presentation. All patients were exposed to textured implants. Surface area analysis confirmed that higher surface area was associated with 64 of the 75 implants used (85.3 percent). Biocell salt loss textured (Allergan, Inamed, and McGhan) implants accounted for 58.7 percent of the implants used in this series. Comparative analysis showed the risk of developing breast implant-associated ALCL to be 14.11 times higher with Biocell textured implants and 10.84 higher with polyurethane (Silimed) textured implants compared with Siltex textured implants. This study has calculated implant-specific risk of breast implant-associated ALCL. Higher-surface-area textured implants have been shown to significantly increase the risk of breast implant-associated ALCL in Australia and New Zealand. The authors present a unifying hypothesis to explain these observations.

Effects of mechanical repetitive load on bone quality around implants in rat maxillae

PubMed Central

Uto, Yusuke; Nakano, Takayoshi; Ishimoto, Takuya; Inaba, Nao; Uchida, Yusuke; Sawase, Takashi

2017-01-01

Greater understanding and acceptance of the new concept “bone quality”, which was proposed by the National Institutes of Health and is based on bone cells and collagen fibers, are required. The novel protein Semaphorin3A (Sema3A) is associated with osteoprotection by regulating bone cells. The aims of this study were to investigate the effects of mechanical loads on Sema3A production and bone quality based on bone cells and collagen fibers around implants in rat maxillae. Grade IV-titanium threaded implants were placed at 4 weeks post-extraction in maxillary first molars. Implants received mechanical loads (10 N, 3 Hz for 1800 cycles, 2 days/week) for 5 weeks from 3 weeks post-implant placement to minimize the effects of wound healing processes by implant placement. Bone structures, bone mineral density (BMD), Sema3A production and bone quality based on bone cells and collagen fibers were analyzed using microcomputed tomography, histomorphometry, immunohistomorphometry, polarized light microscopy and birefringence measurement system inside of the first and second thread (designated as thread A and B, respectively), as mechanical stresses are concentrated and differently distributed on the first two threads from the implant neck. Mechanical load significantly increased BMD, but not bone volume around implants. Inside thread B, but not thread A, mechanical load significantly accelerated Sema3A production with increased number of osteoblasts and osteocytes, and enhanced production of both type I and III collagen. Moreover, mechanical load also significantly induced preferential alignment of collagen fibers in the lower flank of thread B. These data demonstrate that mechanical load has different effects on Sema3A production and bone quality based on bone cells and collagen fibers between the inside threads of A and B. Mechanical load-induced Sema3A production may be differentially regulated by the type of bone structure or distinct stress distribution, resulting in control of bone quality around implants in jaw bones. PMID:29244883

Effects of mechanical repetitive load on bone quality around implants in rat maxillae.

PubMed

Uto, Yusuke; Kuroshima, Shinichiro; Nakano, Takayoshi; Ishimoto, Takuya; Inaba, Nao; Uchida, Yusuke; Sawase, Takashi

2017-01-01

Greater understanding and acceptance of the new concept "bone quality", which was proposed by the National Institutes of Health and is based on bone cells and collagen fibers, are required. The novel protein Semaphorin3A (Sema3A) is associated with osteoprotection by regulating bone cells. The aims of this study were to investigate the effects of mechanical loads on Sema3A production and bone quality based on bone cells and collagen fibers around implants in rat maxillae. Grade IV-titanium threaded implants were placed at 4 weeks post-extraction in maxillary first molars. Implants received mechanical loads (10 N, 3 Hz for 1800 cycles, 2 days/week) for 5 weeks from 3 weeks post-implant placement to minimize the effects of wound healing processes by implant placement. Bone structures, bone mineral density (BMD), Sema3A production and bone quality based on bone cells and collagen fibers were analyzed using microcomputed tomography, histomorphometry, immunohistomorphometry, polarized light microscopy and birefringence measurement system inside of the first and second thread (designated as thread A and B, respectively), as mechanical stresses are concentrated and differently distributed on the first two threads from the implant neck. Mechanical load significantly increased BMD, but not bone volume around implants. Inside thread B, but not thread A, mechanical load significantly accelerated Sema3A production with increased number of osteoblasts and osteocytes, and enhanced production of both type I and III collagen. Moreover, mechanical load also significantly induced preferential alignment of collagen fibers in the lower flank of thread B. These data demonstrate that mechanical load has different effects on Sema3A production and bone quality based on bone cells and collagen fibers between the inside threads of A and B. Mechanical load-induced Sema3A production may be differentially regulated by the type of bone structure or distinct stress distribution, resulting in control of bone quality around implants in jaw bones.

Subchondral pre-solidified chitosan/blood implants elicit reproducible early osteochondral wound-repair responses including neutrophil and stromal cell chemotaxis, bone resorption and repair, enhanced repair tissue integration and delayed matrix deposition

PubMed Central

2013-01-01

Background In this study we evaluated a novel approach to guide the bone marrow-driven articular cartilage repair response in skeletally aged rabbits. We hypothesized that dispersed chitosan particles implanted close to the bone marrow degrade in situ in a molecular mass-dependent manner, and attract more stromal cells to the site in aged rabbits compared to the blood clot in untreated controls. Methods Three microdrill hole defects, 1.4 mm diameter and 2 mm deep, were created in both knee trochlea of 30 month-old New Zealand White rabbits. Each of 3 isotonic chitosan solutions (150, 40, 10 kDa, 80% degree of deaceylation, with fluorescent chitosan tracer) was mixed with autologous rabbit whole blood, clotted with Tissue Factor to form cylindrical implants, and press-fit in drill holes in the left knee while contralateral holes received Tissue Factor or no treatment. At day 1 or day 21 post-operative, defects were analyzed by micro-computed tomography, histomorphometry and stereology for bone and soft tissue repair. Results All 3 implants filled the top of defects at day 1 and were partly degraded in situ at 21 days post-operative. All implants attracted neutrophils, osteoclasts and abundant bone marrow-derived stromal cells, stimulated bone resorption followed by new woven bone repair (bone remodeling) and promoted repair tissue-bone integration. 150 kDa chitosan implant was less degraded, and elicited more apoptotic neutrophils and bone resorption than 10 kDa chitosan implant. Drilled controls elicited a poorly integrated fibrous or fibrocartilaginous tissue. Conclusions Pre-solidified implants elicit stromal cells and vigorous bone plate remodeling through a phase involving neutrophil chemotaxis. Pre-solidified chitosan implants are tunable by molecular mass, and could be beneficial for augmented marrow stimulation therapy if the recruited stromal cells can progress to bone and cartilage repair. PMID:23324433

Biocompatibility of a polyether urethane, polypropylene oxide, and a polyether polyester copolymer. A qualitative and quantitative study of three alloplastic tympanic membrane materials in the rat middle ear.

PubMed

Bakker, D; van Blitterswijk, C A; Hesseling, S C; Koerten, H K; Kuijpers, W; Grote, J J

1990-04-01

The biocompatibility of porous implants made of Estane 5714 F1 polyether urethane, polypropylene oxide, and a poly(ethylene oxide hydantoin) and poly(tetramethylene terephthalate) segmented polyether polyester copolymer (HPOE/PBT copolymer), which were selected as candidates for an alloplastic tympanic membrane, was assessed after implantation in rat middle ears for periods of up to 1 year. Implantation of the materials led to tissue reactions initially associated with the wound-healing process, whereas after 1 month not only the presence of macrophages and foreign-body giant cells surrounding the implant materials but also implant degradation were characteristic for a foreign-body reaction. Macrophages and foreign-body giant cells dominated the picture of the tissue surrounding polypropylene oxide. The altered morphology of these cells, the persistent infiltration of the implantation sites by exudate cells, and the premature death of five rats in the 1-year group suggest that polypropylene oxide degradation was accompanied by the release of toxic substances. Estane and copolymer degradation did not induce tissue responses reflecting implant toxicity, and tympanic membranes given these alloplasts showed a normal healing pattern. Inclusions in the cytoplasm of macrophages associated with degradation and phagocytosis of all of the polymers under study were found to contain iron, silicon, titanium, and aluminum. Growth of fibrous tissue and bone, the latter into Estane and HPOE/PBT copolymer implants, indicated appropriate implant fixation by tissue, although macrophages and foreign-body giant cells were present as well. Especially the fixation of copolymer by ingrowth of bone seems promising in terms of the amount of bone in the pores and the electron-dense bone/copolymer interface. The latter is indicative for bonding osteogenesis. The HPOE/PBT copolymer is a better candidate for alloplastic tympanic membrane than Estane, and the use of polypropylene oxide cannot be recommended.

Hollow fibers - Their applications to the study of mammalian cell function

NASA Technical Reports Server (NTRS)

Hymer, W. C.; Angeline, M.; Harkness, J.; Chu, M.; Grindleland, R.

1984-01-01

The use of hollow fiber technology in cell culture and transplantation is examined. The morphologies of encapsulated pituitary cells before and after implantation into the rat are defined. Implantation experiments using hollow fibers to study mammalian cell functions are described. Consideration is given to examining somatotroph, prolactin, prostrate, fibroblast, and retinal cell functions. These experiments demonstrate that hollow fiber technology is applicable for studying mammalian cell functions.

Nanoengineered implant as a new platform for regenerative nanomedicine using 3D well-organized human cell spheroids

PubMed Central

Keller, Laetitia; Idoux-Gillet, Ysia; Wagner, Quentin; Eap, Sandy; Brasse, David; Schwinté, Pascale; Arruebo, Manuel; Benkirane-Jessel, Nadia

2017-01-01

In tissue engineering, it is still rare today to see clinically transferable strategies for tissue-engineered graft production that conclusively offer better tissue regeneration than the already existing technologies, decreased recovery times, and less risk of complications. Here a novel tissue-engineering concept is presented for the production of living bone implants combining 1) a nanofibrous and microporous implant as cell colonization matrix and 2) 3D bone cell spheroids. This combination, double 3D implants, shows clinical relevant thicknesses for the treatment of an early stage of bone lesions before the need of bone substitutes. The strategy presented here shows a complete closure of a defect in nude mice calvaria after only 31 days. As a novel strategy for bone regenerative nanomedicine, it holds great promises to enhance the therapeutic efficacy of living bone implants. PMID:28138241

Arterial grafts exhibiting unprecedented cellular infiltration and remodeling in vivo: the role of cells in the vascular wall.

PubMed

Row, Sindhu; Peng, Haofan; Schlaich, Evan M; Koenigsknecht, Carmon; Andreadis, Stelios T; Swartz, Daniel D

2015-05-01

To engineer and implant vascular grafts in the arterial circulation of a pre-clinical animal model and assess the role of donor medial cells in graft remodeling and function. Vascular grafts were engineered using Small Intestinal Submucosa (SIS)-fibrin hybrid scaffold and implanted interpositionally into the arterial circulation of an ovine model. We sought to demonstrate implantability of SIS-Fibrin based grafts; examine the remodeling; and determine whether the presence of vascular cells in the medial wall was necessary for cellular infiltration from the host and successful remodeling of the implants. We observed no occlusions or anastomotic complications in 18 animals that received these grafts. Notably, the grafts exhibited unprecedented levels of host cell infiltration that was not limited to the anastomotic sites but occurred through the lumen as well as the extramural side, leading to uniform cell distribution. Incoming cells remodeled the extracellular matrix and matured into functional smooth muscle cells as evidenced by expression of myogenic markers and development of vascular reactivity. Interestingly, tracking the donor cells revealed that their presence was beneficial but not necessary for successful grafting. Indeed, the proliferation rate and number of donor cells decreased over time as the vascular wall was dominated by host cells leading to significant remodeling and development of contractile function. These results demonstrate that SIS-Fibrin grafts can be successfully implanted into the arterial circulation of a clinically relevant animal model, improve our understanding of vascular graft remodeling and raise the possibility of engineering mural cell-free arterial grafts. Copyright © 2015 Elsevier Ltd. All rights reserved.

Characterisation of slab waveguides, fabricated in CaF2 and Er-doped tungsten-tellurite glass by MeV energy N+ ion implantation, using spectroscopic ellipsometry and m-line spectroscopy

NASA Astrophysics Data System (ADS)

Bányász, I.; Berneschi, S.; Lohner, T.; Fried, M.; Petrik, P.; Khanh, N. Q.; Zolnai, Z.; Watterich, A.; Bettinelli, M.; Brenci, M.; Nunzi-Conti, G.; Pelli, S.; Righini, G. C.; Speghini, A.

2010-05-01

Slab waveguides were fabricated in Er-doped tungsten-tellurite glass and CaF2 crystal samples via ion implantation. Waveguides were fabricated by implantation of MeV energy N+ ions at the Van de Graaff accelerator of the Research Institute for Particle and Nuclear Physics, Budapest, Hungary. Part of the samples was annealed. Implantations were carried out at energies of 1.5 MeV (tungsten-tellurite glass) and 3.5 MeV (CaF2). The implanted doses were between 5 x 1012 and 8 x 1016 ions/cm2. Refractive index profile of the waveguides was measured using SOPRA ES4G and Woollam M-2000DI spectroscopic ellipsometers at the Research Institute for Technical Physics and Materials Science, Budapest. Functionality of the waveguides was tested using a home-made instrument (COMPASSO), based on m-line spectroscopy and prism coupling technique, which was developed at the Materials and Photonics Devices Laboratory (MDF Lab.) of the Institute of Applied Physics in Sesto Fiorentino, Italy. Results of both types of measurements were compared to depth distributions of nuclear damage in the samples, calculated by SRIM 2007 code. Thicknesses of the guiding layer and of the implanted barrier obtained by spectroscopic ellipsometry correspond well to SRIM simulations. Irradiationinduced refractive index modulation saturated around a dose of 8 x 1016 ions/cm2 in tungsten-tellurite glass. Annealing of the implanted waveguides resulted in a reduction of the propagation loss, but also reduced the number of supported guiding modes at the lower doses. We report on the first working waveguides fabricated in an alkali earth halide crystal implanted by MeV energy medium-mass ions.

Generation of an immortalized mesenchymal stem cell line producing a secreted biosensor protein for glucose monitoring

PubMed Central

Weisman, Itamar; Romano, Jacob; Ivics, Zoltán; Izsvák, Zsuzsanna; Barkai, Uriel

2017-01-01

Diabetes is a chronic disease characterized by high levels of blood glucose. Diabetic patients should normalize these levels in order to avoid short and long term clinical complications. Presently, blood glucose monitoring is dependent on frequent finger pricking and enzyme based systems that analyze the drawn blood. Continuous blood glucose monitors are already on market but suffer from technical problems, inaccuracy and short operation time. A novel approach for continuous glucose monitoring is the development of implantable cell-based biosensors that emit light signals corresponding to glucose concentrations. Such devices use genetically modified cells expressing chimeric genes with glucose binding properties. MSCs are good candidates as carrier cells, as they can be genetically engineered and expanded into large numbers. They also possess immunomodulatory properties that, by reducing local inflammation, may assist long operation time. Here, we generated a novel immortalized human MSC line co-expressing hTERT and a secreted glucose biosensor transgene using the Sleeping Beauty transposon technology. Genetically modified hMSCs retained their mesenchymal characteristics. Stable transgene expression was validated biochemically. Increased activity of hTERT was accompanied by elevated and constant level of stem cell pluripotency markers and subsequently, by MSC immortalization. Furthermore, these cells efficiently suppressed PBMC proliferation in MLR transwell assays, indicating that they possess immunomodulatory properties. Finally, biosensor protein produced by MSCs was used to quantify glucose in cell-free assays. Our results indicate that our immortalized MSCs are suitable for measuring glucose concentrations in a physiological range. Thus, they are appropriate for incorporation into a cell-based, immune-privileged, glucose-monitoring medical device. PMID:28949988

Generation of an immortalized mesenchymal stem cell line producing a secreted biosensor protein for glucose monitoring.

PubMed

Siska, Evangelia K; Weisman, Itamar; Romano, Jacob; Ivics, Zoltán; Izsvák, Zsuzsanna; Barkai, Uriel; Petrakis, Spyros; Koliakos, George

2017-01-01

Diabetes is a chronic disease characterized by high levels of blood glucose. Diabetic patients should normalize these levels in order to avoid short and long term clinical complications. Presently, blood glucose monitoring is dependent on frequent finger pricking and enzyme based systems that analyze the drawn blood. Continuous blood glucose monitors are already on market but suffer from technical problems, inaccuracy and short operation time. A novel approach for continuous glucose monitoring is the development of implantable cell-based biosensors that emit light signals corresponding to glucose concentrations. Such devices use genetically modified cells expressing chimeric genes with glucose binding properties. MSCs are good candidates as carrier cells, as they can be genetically engineered and expanded into large numbers. They also possess immunomodulatory properties that, by reducing local inflammation, may assist long operation time. Here, we generated a novel immortalized human MSC line co-expressing hTERT and a secreted glucose biosensor transgene using the Sleeping Beauty transposon technology. Genetically modified hMSCs retained their mesenchymal characteristics. Stable transgene expression was validated biochemically. Increased activity of hTERT was accompanied by elevated and constant level of stem cell pluripotency markers and subsequently, by MSC immortalization. Furthermore, these cells efficiently suppressed PBMC proliferation in MLR transwell assays, indicating that they possess immunomodulatory properties. Finally, biosensor protein produced by MSCs was used to quantify glucose in cell-free assays. Our results indicate that our immortalized MSCs are suitable for measuring glucose concentrations in a physiological range. Thus, they are appropriate for incorporation into a cell-based, immune-privileged, glucose-monitoring medical device.

Processing of silicon solar cells by ion implantation and laser annealing

NASA Technical Reports Server (NTRS)

Minnucci, J. A.; Matthei, K. W.; Greenwald, A. C.

1981-01-01

Methods to improve the radiation tolerance of silicon cells for spacecraft use are described. The major emphasis of the program was to reduce the process-induced carbon and oxygen impurities in the junction and base regions of the solar cell, and to measure the effect of reduced impurity levels on the radiation tolerance of cells. Substrates of 0.1, 1.0 and 10.0 ohm-cm float-zone material were used as starting material in the process sequence. High-dose, low-energy ion implantation was used to form the junction in n+p structures. Implant annealing was performed by conventional furnace techniques and by pulsed laser and pulsed electron beam annealing. Cells were tested for radiation tolerance at Spire and NASA-LeRC. After irradiation by 1 MeV electrons to a fluence of 10 to the 16th power per sq cm, the cells tested at Spire showed no significant process induced variations in radiation tolerance. However, for cells tested at Lewis to a fluence of 10 to the 15th power per sq cm, ion-implanted cells annealed in vacuum by pulsed electron beam consistently showed the best radiation tolerance for all cell resistivities.

Autonomous assembly of epithelial structures by subrenal implantation of dissociated embryonic inner-ear cells.

PubMed

Wang, Li; Zhang, Kaiqing; Zhu, Helen He; Gao, Wei-Qiang

2015-05-27

Microenvironment and cell-cell interactions play an important role during embryogenesis and are required for the stemness and differentiation of stem cells. The inner-ear sensory epithelium, containing hair cells and supporting cells, is derived from the stem cells within the otic vesicle at early embryonic stages. However, whether or not such microenvironment or cell-cell interactions within the embryonic otic tissue have the capacity to regulate the proliferation and differentiation of stem cells and to autonomously reassemble the cells into epithelial structures is unknown. Here, we report that on enzymatic digestion and dissociation to harvest all the single cells from 13.5-day-old rat embryonic (E13.5) inner-ear tissue as well as on implantation of these cells under renal capsules; the dissociated cells are able to reassemble themselves to form epithelial structures as early as 7 days after implantation. By 25 days after implantation, more mature epithelial structures are formed. Immunostaining with cell-type-specific markers reveals that hair cells and supporting cells are not only formed, but are also well aligned with the hair cells located in the apical layer surrounded by the supporting cells. These findings suggest that microenvironment and cell-cell interactions within the embryonic inner-ear tissue have the autonomous signals to induce the formation of sensory epithelial structures. This method may also provide a useful system to study the potential of stem cells to differentiate into hair cells in vivo.

Antinociceptive effect of intrathecal microencapsulated human pheochromocytoma cell in a rat model of bone cancer pain.

PubMed

Li, Xiao; Li, Guoqi; Wu, Shaoling; Zhang, Baiyu; Wan, Qing; Yu, Ding; Zhou, Ruijun; Ma, Chao

2014-07-08

Human pheochromocytoma cells, which are demonstrated to contain and release met-enkephalin and norepinephrine, may be a promising resource for cell therapy in cancer-induced intractable pain. Intrathecal injection of alginate-poly (l) lysine-alginate (APA) microencapsulated human pheochromocytoma cells leads to antinociceptive effect in a rat model of bone cancer pain, and this effect was blocked by opioid antagonist naloxone and alpha 2-adrenergic antagonist rauwolscine. Neurochemical changes of cerebrospinal fluid are in accordance with the analgesic responses. Taken together, these data support that human pheochromocytoma cell implant-induced antinociception was mediated by met-enkephalin and norepinephrine secreted from the cell implants and acting at spinal receptors. Spinal implantation of microencapsulated human pheochromocytoma cells may provide an alternative approach for the therapy of chronic intractable pain.

Ion penetration depth in the plant cell wall

NASA Astrophysics Data System (ADS)

Yu, L. D.; Vilaithong, T.; Phanchaisri, B.; Apavatjrut, P.; Anuntalabhochai, S.; Evans, P.; Brown, I. G.

2003-05-01

This study investigates the depth of ion penetration in plant cell wall material. Based on the biological structure of the plant cell wall, a physical model is proposed which assumes that the wall is composed of randomly orientated layers of cylindrical microfibrils made from cellulose molecules of C 6H 12O 6. With this model, we have determined numerical factors for ion implantation in the plant cell wall to correct values calculated from conventional ion implantation programs. Using these correction factors, it is possible to apply common ion implantation programs to estimate the ion penetration depth in the cell for bioengineering purposes. These estimates are compared with measured data from experiments and good agreement is achieved.

Increased levels of CCR7(lo)PD-1(hi) CXCR5+ CD4+ T cells, and associated factors Bcl-6, CXCR5, IL-21 and IL-6 contribute to repeated implantation failure.

PubMed

Gong, Qiaoqiao; Zhu, Yuejie; Pang, Nannan; Ai, Haiquan; Gong, Xiaoyun; La, Xiaolin; Ding, Jianbing

2017-12-01

In vitro fertilization-embryo transfer (IVF-ET) can be used by infertile couples to assist with reproduction; however, failure of the embryo to implant into the endometrial lining results in failure of the IVF treatment. The present study investigated the expression of chemokine receptor 7 (CCR7)(lo) programmed death-1(PD-1)(hi) chemokine receptor type 5 (CXCR5) + cluster of differentiation 4 (CD4) + T cells and associated factors in patients with repeated implantation failure (RIF). A total of 30 females with RIF and 30 healthy females were enrolled in the current study. Flow cytometry was used to detect the proportion of CCR7(lo)PD-1(hi) CXCR5 + CD4 + T cells in the peripheral blood. Cytokine bead arrays were performed to detect the levels of interleukin (IL)-6, -4 and -2 in the serum. ELISAs were used to detect the level of IL-21 in the serum. Quantitative real time polymerase chain reaction analysis and immunohistochemistry were used to investigate the expression of B-cell lymphoma 6 (Bcl-6), chemokine receptor type 5 (CXCR5) and IL-21 in the endometrium. The results revealed that the percentage of CCR7(lo)PD-1(hi) CXCR5 + CD4 + T cells was increased in the RIF group compared with the control group during the mid luteal phase. The mRNA and protein levels of Bcl-6, IL-21 and CXCR5 in the endometrium and the concentrations of IL-21 and IL-6 in the serum were significantly increased in the RIF group; however, no significant difference was observed between the two groups in regards to the expression of IL-4 and IL-2. Furthermore, a significant positive correlation was identified between the percentage of CCR7(lo)PD-1(hi) CXCR5 + CD4 + T cells and IL-21 and IL-6 levels. The expression of IL-21 also had a positive correlation with Bcl-6 and CXCR5 expression in the RIF group. These results suggest that increased levels of CCR7(lo)PD-1(hi) CXCR5 + CD4 + T cells and associated factors contribute to RIF and could therefore be a potential therapeutic target.

A negative ion beam application to artificial formation of neuron network in culture

NASA Astrophysics Data System (ADS)

Tsuji, Hiroshi; Sato, Hiroko; Baba, Takahiro; Gotoh, Yasuhito; Ishikawa, Junzo

2000-02-01

A negative ion beam modification of the biocompatibility of polystyrene surface was investigated for the artificial formation of neuron network in culture with respect to negative ion species. Negative ions of silver, copper or carbon were implanted in nontreated polystyrene (NTPS) dishes at conditions of 20 keV and 3×1015ions/cm2 through a mask with many slits of 60 μm in width. For the surface wettability, the contact angle of ion-implanted NTPS was about 75° for silver-negative ions, which was lower than 86° of the original NTPS. For carbon implantation, on the contrary, the contact angles did not change from the original value. In culture experiment using neuron cells of PC-12h (rat adrenal pheochromocytoma), the cells cultured with serum medium in two days showed the cell attachment and growth in number only at the ion-implanted region on NTPS for all ion species. In another two days in culture with nonserum medium including a nerve growth factor, the outgrowth of neural protrusions was also observed only at the ion-implanted region for all ion species. There was a difference in number of attached cells for ion species. The silver-negative ion-implanted NTPS had a large effect for cell attachment compared with other two ion species. This reason is considered to be due to the lowest contract angles among them.

Th 17 Cells and Nesfatin-1 are associated with Spontaneous Abortion in the CBA/j × DBA/2 Mouse Model

PubMed Central

Chung, Yiwa; Kim, Heejeong; Im, Eunji; Kim, Philjae; Yang, Hyunwon

2015-01-01

The pregnancy and abortion process involves a complex mechanism with various immune cells present in the implantation sites and several hormones associated with pregnancy, such as leptin, ghrelin and nesfatin-1. However, the mechanism underlying spontaneous abortion by maternal T helper 17 (Th17) present in the implantation sites and nesfatin-1, which is of anorexigenic hormones, is not fully understood so far. Therefore, the purpose of this study was to examine the possible roles of Th17 cells present in the implantation sites and nesfatin-1 expressed in the uterus on spontaneous abortion using the CBA/j × DBA/2 mouse model. Th17 transcription factor, ROR-γt mRNA expression was significantly increased in the abortion sites compared with the implantation sites of abortion model mice on day 14.5 and 19.5 of pregnancy. In addition, the expression levels of IL-17A mRNA were significantly higher in abortion sites than in implantation sites on day 14.5 and 19.5. Moreover, the nesfatin-1/NUCB2 protein and mRNA levels were increased in abortion sites compared with levels in implantation sites of both normal pregnant and abortion model mice on day 14.5 of pregnancy. Interestingly, nesfatin- 1/NUCB2 serum levels were not changed throughout the whole pregnancy in abortion model mice, but its serum level was dramatically increased on day 14.5, and then rapidly decreased on day 19.5 in normal pregnant mice. In this study, we showed for the first time the expression of nesfatin-1/NUCB2 mRNA and protein in implantation sites during pregnancy. The present results suggest that Th17 cells in the uterus may play an important role in the period of implantation and for maintenance of pregnancy. Furthermore, the present results suggest that Th17 cells in implantation sites may be a key regulator for maintenance of pregnancy and provides evidence that activation of these cells may be regulated by nesfatin-1/NUCB2. Further study is needed to elucidate the role of nesfatin-1 expressed in the uterus during pregnancy. PMID:26973976

Perianal implantation of bioengineered human internal anal sphincter constructs intrinsically innervated with human neural progenitor cells.

PubMed

Raghavan, Shreya; Miyasaka, Eiichi A; Gilmont, Robert R; Somara, Sita; Teitelbaum, Daniel H; Bitar, Khalil N

2014-04-01

The internal anal sphincter (IAS) is a major contributing factor to pressure within the anal canal and is required for maintenance of rectoanal continence. IAS damage or weakening results in fecal incontinence. We have demonstrated that bioengineered, intrinsically innervated, human IAS tissue replacements possess key aspects of IAS physiology, such as the generation of spontaneous basal tone and contraction/relaxation in response to neurotransmitters. The objective of this study is to demonstrate the feasibility of implantation of bioengineered IAS constructs in the perianal region of athymic rats. Human IAS tissue constructs were bioengineered from isolated human IAS circular smooth muscle cells and human enteric neuronal progenitor cells. After maturation of the bioengineered constructs in culture, they were implanted operatively into the perianal region of athymic rats. Platelet-derived growth factor was delivered to the implanted constructs through a microosmotic pump. Implanted constructs were retrieved from the animals 4 weeks postimplantation. Animals tolerated the implantation well, and there were no early postoperative complications. Normal stooling was observed during the implantation period. At harvest, implanted constructs were adherent to the perirectal rat tissue and appeared healthy and pink. Immunohistochemical analysis revealed neovascularization. Implanted smooth muscle cells maintained contractile phenotype. Bioengineered constructs responded in vitro in a tissue chamber to neuronally evoked relaxation in response to electrical field stimulation and vasoactive intestinal peptide, indicating the preservation of neuronal networks. Our results indicate that bioengineered innervated IAS constructs can be used to augment IAS function in an animal model. This is a regenerative medicine based therapy for fecal incontinence that would directly address the dysfunction of the IAS muscle. Copyright © 2014 Mosby, Inc. All rights reserved.

Ion-implanted WN 0.25{mu}m gate MESFET fabricated using I-line photolithography for application to MMIC and digital IC

DOE Office of Scientific and Technical Information (OSTI.GOV)

Oh, E.O.; Yang, J.W.; Park, C.S.

1995-12-31

Straightforward WN 0.25{mu}m gate MESFET process based on direct ion-implantation and i-line photolithography with double exposure process has produced high performance MESFETs. The maximum transconductance of 600mS/mm and the k-factor of 450ms/Vmm were obtained. As high as 65GHz of cut-off frequency has been realized without any deembedding of parasitic effects. The MESFET shows the minimum noise figure of 0.87 dB and the associated gain of 9.97dB at 12GHz.

Liver cell therapy and tissue engineering for transplantation.

PubMed

Vacanti, Joseph P; Kulig, Katherine M

2014-06-01

Liver transplantation remains the only definitive treatment for liver failure and is available to only a tiny fraction of patients with end-stage liver diseases. Major limitations for the procedure include donor organ shortage, high cost, high level of required expertise, and long-term consequences of immune suppression. Alternative cell-based liver therapies could potentially greatly expand the number of patients provided with effective treatment. Investigative research into augmenting or replacing liver function extends into three general strategies. Bioartificial livers (BALs) are extracorporeal devices that utilize cartridges of primary hepatocytes or cell lines to process patient plasma. Injection of liver cell suspensions aims to foster organ regeneration or provide a missing metabolic function arising from a genetic defect. Tissue engineering recreates the organ in vitro for subsequent implantation to augment or replace patient liver function. Translational models and clinical trials have highlighted both the immense challenges involved and some striking examples of success. Copyright © 2014. Published by Elsevier Inc.

Endometrial immune markers are potential predictors of normal fertility and pregnancy after in vitro fertilization.

PubMed

Kofod, Louise; Lindhard, Anette; Bzorek, Michael; Eriksen, Jens Ole; Larsen, Lise Grupe; Hviid, Thomas Vauvert F

2017-09-01

Elucidating immune mechanisms in the endometrium, which lead to the success of implantation and pregnancy, is important in reproductive medicine. Studies of immune cell abundance have shown conflicting results, and the expression and importance of HLA class Ib proteins in pre-implantation endometrium have not yet been investigated. The study population consisted of four subgroups: a hydrosalpinx, a salpingectomy, an unexplained infertility, and a fertile control group. Endometrial samples were collected during the implantation window. Immune markers (CD56 + and CD16 + cells, FoxP3 + Tregs, HLA-G, HLA-F) were quantified in the samples. The outcome of the subsequent IVF treatment was recorded. Increased CD56 + uNK cells and high HLA-G expression served as predictor for successful pregnancy outcome. HLA-F expression was positively correlated with uNK cells, being indirectly predictive for achieving pregnancy. Endometrial uNK cell abundance in the pre-implantation endometrium seems to be important for normal fertility and pregnancy success, and they may be used as clinical markers to predict implantation success in IVF. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Regeneration of tracheal epithelium using mouse induced pluripotent stem cells.

PubMed

Ikeda, Masakazu; Imaizumi, Mitsuyoshi; Yoshie, Susumu; Otsuki, Koshi; Miyake, Masao; Hazama, Akihiro; Wada, Ikuo; Omori, Koichi

2016-01-01

Conclusion The findings demonstrated the potential use of induced pluripotent stem cells for regeneration of tracheal epithelium. Objective Autologous tissue implantation techniques using skin or cartilage are often applied in cases of tracheal defects with laryngeal inflammatory lesions and malignant tumor invasion. However, these techniques are invasive with an unstable clinical outcome. The purpose of this study was to investigate regeneration in a tracheal defect site of nude rats after implantation of ciliated epithelium that was differentiated from induced pluripotent stem cells. Method Embryoid bodies were formed from mouse induced pluripotent stem cells. They were cultured with growth factors for 5 days, and then cultured at the air-liquid interface. The degree of differentiation achieved prior to implantation was determined by histological findings and the results of real-time polymerase chain reaction. Embryoid bodies including ciliated epithelium were embedded into collagen gel that served as an artificial scaffold, and then implanted into nude rats, creating an 'air-liquid interface model'. Histological evaluation was performed 7 days after implantation. Results The ciliated epithelial structure survived on the lumen side of regenerated tissue. It was demonstrated histologically that the structure was composed of ciliated epithelial cells.

Direct in vivo inflammatory cell-induced corrosion of CoCrMo alloy orthopedic implant surfaces.

PubMed

Gilbert, Jeremy L; Sivan, Shiril; Liu, Yangping; Kocagöz, Sevi B; Arnholt, Christina M; Kurtz, Steven M

2015-01-01

Cobalt-chromium-molybdenum (CoCrMo) alloy, used for over five decades in orthopedic implants, may corrode and release wear debris into the body during use. These degradation products may stimulate immune and inflammatory responses in vivo. We report here on evidence of direct inflammatory cell-induced corrosion of human implanted and retrieved CoCrMo implant surfaces. Corrosion morphology on CoCrMo implant surfaces, in unique and characteristic patterns, and the presence of cellular remnants and biological materials intimately entwined with the corrosion indicates direct cellular attack under the cell membrane region of adhered and/or migrating inflammatory cells. Evidence supports a Fenton-like reaction mechanism driving corrosion in which reactive oxygen species are the major driver of corrosion. Using in vitro tests, large increases in corrosion susceptibility of CoCrMo were seen (40-100 fold) when immersed in phosphate buffered saline solutions modified with hydrogen peroxide and hydrochloric acid to represent the chemistry under inflammatory cells. This discovery raises significant new questions about the clinical consequences of such corrosion interactions, the role of patient inflammatory reactions, and the detailed mechanisms at play. © 2014 Wiley Periodicals, Inc.

Direct In Vivo Inflammatory Cell-Induced Corrosion of CoCrMo Alloy Orthopedic Implant Surfaces

PubMed Central

Gilbert, Jeremy L.; Sivan, Shiril; Liu, Yangping; Kocagöz, Sevi; Arnholt, Christina; Kurtz, Steven M.

2014-01-01

Cobalt-chromium-molybdenum alloy, used for over four decades in orthopedic implants, may corrode and release wear debris into the body during use. These degradation products may stimulate immune and inflammatory responses in vivo. We report here on evidence of direct inflammatory cell-induced corrosion of human implanted and retrieved CoCrMo implant surfaces. Corrosion morphology on CoCrMo implant surfaces, in unique and characteristic patterns, and the presence of cellular remnants and biological materials intimately entwined with the corrosion indicates direct cellular attack under the cell membrane region of adhered and/or migrating inflammatory cells. Evidence supports a Fenton-like reaction mechanism driving corrosion in which reactive oxygen species are the major driver of corrosion. Using in vitro tests, large increases in corrosion susceptibility of CoCrMo were seen (40 to 100 fold) when immersed in phosphate buffered saline solutions modified with hydrogen peroxide and HCl to represent the chemistry under inflammatory cells. This discovery raises significant new questions about the clinical consequences of such corrosion interactions, the role of patient inflammatory reactions, and the detailed mechanisms at play. PMID:24619511

Variant RONΔ160 of the RON receptor tyrosine kinase promotes the growth and invasion in vitro and in vivo in gastric cancer cell lines.

PubMed

Zhou, Dong-Hui; Li, Chao; Yang, Li-Na

2015-01-01

Recepteur d'origine nantais (RON) is a receptor tyrosine kinase whose overexpression has been observed in human gastric cancers. This study aimed to determine whether overexpression of the variant RONΔ160 could induce tumorigenicity of gastric cancer cells in vitro or in vivo, and whether its specific small molecule inhibitor (Compound I) could inhibit the effect of RONΔ160. We constructed human gastric cancer cell line MGC-803 that was stably transfected with a recombinant plasmid expressing RONΔ160, and the effect of RONΔ160 overexpression and macrophage-stimulating protein (MSP) activation on proliferation, migration and invasion abilities of MGC-803 cells were evaluated. Tumor-bearing mice with gastric cancer cells were used to analyze the effects of RONΔ160 overexpression and Compound I on implanted tumor growth. In vitro, overexpression of RONΔ160 in MGC-803 cells resulted changes to their cell morphology, and promoted cell proliferation, migration and invasion. In addition, overexpression of RONΔ160 increased the proportion of cells in the S phase. The effect of RONΔ160 was significantly enhanced by induction of MSP inducing (p < 0.05). In vivo, RONΔ160 promoted the growth of MGC-803 cells in nude mice, including increased tumor size and weight, and lower tumor incubation period. The Compound I inhibited the tumorigenic abilities of RONΔ160 (p <0.05). The results indicate that overexpression of the variant RONΔ160 altered the phenotype and tumorigenicity of MGC-803 cells. Its specific small molecule inhibitor could inhibit the effect of RONΔ160. Therefore, the variant RONΔ160 may become a potential therapeutic target for gastric cancer.

WINGLESS (WNT) signaling is a progesterone target for rat uterine stromal cell proliferation

PubMed Central

Talbott, Alex; Bhusri, Anuradha; Krumsick, Zach; Foster, Sierra; Wormington, Joshua; Kimler, Bruce F

2016-01-01

Preparation of mammalian uterus for embryo implantation requires a precise sequence of cell proliferation. In rodent uterus, estradiol stimulates proliferation of epithelial cells. Progesterone operates as a molecular switch and redirects proliferation to the stroma by down-regulating glycogen synthase kinase-3β (GSK-3β) and stimulating β-catenin accumulation in the periluminal stromal cells. In this study, the WNT signal involved in the progesterone-dependent proliferative switch was investigated. Transcripts of four candidate Wnt genes were measured in the uteri from ovariectomized (OVX) rats, progesterone-pretreated (3 days of progesterone, 2mg/daily) rats, and progesterone-pretreated rats given a single dose (0.2µg) of estradiol. The spatial distribution of the WNT proteins was determined in the uteri after the same treatments. Wnt5a increased in response to progesterone and the protein emerged in the periluminal stromal cells of progesterone-pretreated rat uteri. To investigate whether WNT5A was required for proliferation, uterine stromal cell lines were stimulated with progesterone (1µM) and fibroblast growth factor (FGF, 50ng/mL). Proliferating stromal cells expressed a two-fold increase in WNT5A protein at 12h post stimulation. Stimulated stromal cells were cultured with actinomycin D (25µg/mL) to inhibit new RNA synthesis. Relative Wnt5a expression increased at 4 and 6 h of culture, suggesting that progesterone plus FGF preferentially increased Wnt5a mRNA stability. Knockdown of Wnt5a in uterine stromal cell lines inhibited stromal cell proliferation and decreased Wnt5a mRNA. The results indicate that progesterone initiates and synchronizes uterine stromal cell proliferation by increasing WNT5A expression and signaling. PMID:26975616

Combinatorial growth of oxide nanoscaffolds and its influence in osteoblast cell adhesion

NASA Astrophysics Data System (ADS)

Acevedo-Morantes, Claudia Y.; Irizarry-Ortiz, Roberto A.; Caceres-Valencia, Pablo G.; Singh, Surinder P.; Ramirez-Vick, Jaime E.

2012-05-01

We report a novel method for high-throughput investigations on cell-material interactions based on metal oxide nanoscaffolds. These scaffolds possess a continuous gradient of various titanium alloys allowing the compositional and morphological variation that could substantially improve the formation of an osseointegrative interface with bone. The model nanoscaffold has been fabricated on commercially pure titanium (cp-Ti) substrate with a compositional gradients of tin (Sn), chromium (Cr), and niobium (Nb) deposited using a combinatorial approach followed by annealing to create native oxide surface. As an invitro test system, the human fetal osteoblastic cell line (hFOB 1.19) has been used. Cell-adhesion of hFOB 1.19 cells and the suitability of these alloys have been evaluated for cell-morphology, cell-number, and protein adsorption. Although, cell-morphology was not affected by surface composition, cell-proliferation rates varied significantly with surface metal oxide composition; with the Sn- and Nb-rich regions showing the highest proliferation rate and the Cr-rich regions presenting the lowest. The results suggest that Sn and Nb rich regions on surface seems to promote hFOB 1.19 cell proliferation and may therefore be considered as implant material candidates that deserve further analysis.

Early bone anchorage to micro- and nano-topographically complex implant surfaces in hyperglycemia.

PubMed

Ajami, Elnaz; Bell, Spencer; Liddell, Robert S; Davies, John E

2016-07-15

The aim of this work was to investigate the effect of implant surface design on early bone anchorage in the presence of hyperglycemia. 108 Wistar rats were separated into euglycemic (EG) controls and STZ-treated hyperglycemic (HG) groups, and received bilateral femoral custom rectangular implants of two surface topographies: grit blasted (GB) and grit-blast with a superimposed calcium phosphate nanotopography (GB-DCD). The peri-implant bone was subjected to a tensile disruption test 5, 7, and 9days post-operatively (n=28/time point); the force was measured; and the residual peri-implant bone was observed by scanning electron microscopy (SEM). Disruption forces at 5days were not significantly different from zero for the GB implants (p=0.24) in either metabolic group; but were for GB+DCD implants in both metabolic groups (p<0.001). Contact osteogenesis was greater on GB-DCD than the GB surface. The nano-and micro-surfaced implants showed significantly different disruption forces at all time points (e.g. >15N and <5N respectively at 9days). Such differences were not seen within the GB implants, as all values were very low (<5N). Even in hyperglycemia the GB-DCD surface outperformed the GB surfaces in both metabolic groups. Significantly, SEM of peri-implant bone showed compromised intra-fibrillar collagen mineralization in hyperglycemia, while inter-fibrillar and cement line mineralization remained unaffected. Enhanced bone anchorage to the implant surfaces was observed on the nanotopographically complex surface independent of metabolic group. The compromised intra-fibrillar mineralization observed provides a mechanism by which early bone mineralization is affected in hyperglycemia. It is generally accepted that the hyperglycemia associated with diabetes mellitus compromises bone quality, although the mechanism by which this occurs is unknown. Uncontrolled hyperglycemia is therefore a contra-indication for bone implant placement. It is also known that nano-topographically complex implant surfaces accelerate early peri-implant healing. In this report we show that, in our experimental model, nano-topographically complex surfaces can mitigate the compromised bone healing seen in hyperglycemia. Importantly, we also provide a mechanistic explanation for compromised bone quality in hyperglycemia. We show that intra-fibrillar collagen mineralization is compromised in hyperglycemia, but that interfibrillar and cement line mineralization, remain unaffected. Copyright © 2016 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Expression of a model gene in prostate cancer cells lentivirally transduced in vitro and in vivo.

PubMed

Bastide, C; Maroc, N; Bladou, F; Hassoun, J; Maitland, N; Mannoni, P; Bagnis, C

2003-01-01

In a preclinical model for prostate cancer gene therapy, we have tested lentiviral vectors as a practical possibility for the transfer and long-term expression of the EGFP gene both in vitro and in vivo. The human prostate cancer cell lines DU145 and PC3 were transduced using experimental conditions which permitted analysis of the expression from a single proviral vector per cell. The transduced cells stably expressed the EGFP transgene for 4 months. After injection of the transduced cell populations into Nod-SCID mice a decrease in EGFP was only observed in a minority of cases, while the majority of tumors maintained transgene expression at in vitro levels. In vivo injection of viral vector preparations directly into pre-established subcutaneous or orthotopic tumor masses, obtained by implantation of untransduced PC3 and DU145 cells led to a high transduction efficiency. While the efficiency of direct intratumoral transduction was proportional to the dose of virus injected, the results indicated some technical limitations inherent in these approaches to prostate cancer gene therapy.

Effects of cell-attachment and extracellular matrix on bone formation in vivo in collagen-hydroxyapatite scaffolds.

PubMed

Villa, Max M; Wang, Liping; Rowe, David W; Wei, Mei

2014-01-01

Cell-based tissue engineering can be used to replace missing or damaged bone, but the optimal methods for delivering therapeutic cells to a bony defect have not yet been established. Using transgenic reporter cells as a donor source, two different collagen-hydroxyapatite (HA) scaffolds, and a critical-size calvarial defect model, we investigated the effect of a cell-attachment period prior to implantation, with or without an extracellular matrix-based seeding suspension, on cell engraftment and osteogenesis. When quantitatively compared, the in-house scaffold implanted immediately had a higher mean radiopacity than in-house scaffolds incubated overnight. Both scaffold types implanted immediately had significantly higher area fractions of donor cells, while the in-house collagen-HA scaffolds implanted immediately had higher area fractions of the mineralization label compared with groups incubated overnight. When the cell loading was compared in vitro for each delivery method using the in-house scaffold, immediate loading led to higher numbers of delivered cells. Immediate loading may be preferable in order to ensure robust bone formation in vivo. The use of a secondary ECM carrier improved the distribution of donor cells only when a pre-attachment period was applied. These results have improved our understanding of cell delivery to bony defects in the context of in vivo outcomes.