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Sample records for acellular bone matrix

  1. Socket Preservation Therapy with Acellular Dermal Matrix and Mineralized Bone Allograft After Tooth Extraction in Humans: A Clinical and Histomorphometric Study.

    PubMed

    Fernandes, Patricia Garani; Muglia, Valdir Antonio; Reino, Danilo Maeda; Maia, Luciana Prado; de Moraes Grisi, Marcio Fernando; de Souza, Sergio Luís; Taba, Mario; Palioto, Daniela Bazan; de Almeida, Adriana G; Novaes, Arthur Belém

    2016-01-01

    The aim of this study was to analyze through clinical and histomorphometric parameters the use of acellular dermal matrix (ADM) with or without mineralized bone allograft (AB) on bone formation in human alveoli after a 6- to 8-month healing period. A total of 19 patients in need of extraction of the maxillary anterior teeth were selected and randomly assigned to the test group (ADM plus AB) or to the control group (ADM only). Clinical and histomorphometric measurements and histologic analysis were recorded 6 to 8 months after ridge preservation procedures. Clinical parameters and amount of mineralized and nonmineralized tissue were measured and analyzed. In the clinical measurements, the test group showed reduced bone loss in the buccopalatal dimension after 6 to 8 months (intragroup analysis P < .01). Histologic findings showed higher percentages of mineralized tissue and lower percentages of nonmineralized tissue in the test group when compared with the control group (P < .05). In this randomized controlled clinical and histomorphometric study in humans, acellular dermal matrix in association with mineralized bone allograft reduced alveolar bone loss in the anterior maxillae both in height and width after a follow-up period of 6 to 8 months. PMID:26901306

  2. Effects of Acellular Amniotic Membrane Matrix and Bone Marrow-Derived Mesenchymal Stem Cells in Improving Random Skin Flap Survival in Rats

    PubMed Central

    Chehelcheraghi, Farzaneh; Eimani, Hossein; Homayoonsadraie, Seyed; Torkaman, Giti; Amini, Abdollah; Alavi Majd, Hamid; Shemshadi, Hashem

    2016-01-01

    Background The necrotic skin flap represents a great challenge in plastic and reconstructive surgery. In this study, we evaluated the effect of bioscaffolds, acellular amniotic membranes (AAMs), and bone marrow-derived mesenchymal stem cells (BM-MSCs) on random skin flap (RSF) survival in rats by applying a cell-free extracellular matrix scaffold as a supportive component for the growth and proliferation of BM-MSCs on RSFs. AAM matrix scaffolds were created by incubating AMs in ethylenediaminetetraacetic acid 0.05% at 37°C, and cell scrapers were used. Objectives The aim of the present study was to assess the effect of AAM as a scaffold in TE, and combined with transplanted BM-MSCs, on the survival of RSFs and on the biomechanical parameters of the incision-wound flap margins 7 days after flap elevation. Materials and Methods BM-MSCs and AAMs were transplanted into subcutaneous tissue in the flap area. On the 7th postoperative day, the surviving flap areas were measured using digital imaging software, and the flap tissue was collected for evaluation. Forty rats were randomly divided into four groups of 10 each: group 1 received an AAM injection; group 2 underwent BM-MSC transplantation; group 3 received both AAM injection + BM-MSC transplantation; and group 4 was the control group, receiving only saline. Results The survival area in the AAM/BM-MSC group was significantly higher than in the control group (18.49 ± 1.58 versus 7.51 ± 2.42, P < 0.05). The biomechanical assessment showed no significant differences between the experimental groups and the control group (P > 0.05), and there was no correlation with flap survival. Conclusions Our findings showed that the treatment of flaps with BM-MSC and AAM transplantations significantly promoted flap survival compared to a control group. The viability of the flap was improved by combining BM-MSCs with AAM matrix scaffolds.

  3. Cartilage oligomeric matrix protein enhances the vascularization of acellular nerves

    PubMed Central

    Cui, Wei-ling; Qiu, Long-hai; Lian, Jia-yan; Li, Jia-chun; Hu, Jun; Liu, Xiao-lin

    2016-01-01

    Vascularization of acellular nerves has been shown to contribute to nerve bridging. In this study, we used a 10-mm sciatic nerve defect model in rats to determine whether cartilage oligomeric matrix protein enhances the vascularization of injured acellular nerves. The rat nerve defects were treated with acellular nerve grafting (control group) alone or acellular nerve grafting combined with intraperitoneal injection of cartilage oligomeric matrix protein (experimental group). As shown through two-dimensional imaging, the vessels began to invade into the acellular nerve graft from both anastomotic ends at day 7 post-operation, and gradually covered the entire graft at day 21. The vascular density, vascular area, and the velocity of revascularization in the experimental group were all higher than those in the control group. These results indicate that cartilage oligomeric matrix protein enhances the vascularization of acellular nerves. PMID:27127495

  4. Effects of Acellular Amniotic Membrane Matrix and Bone Marrow-Derived Mesenchymal Stem Cells in Improving Random Skin Flap Survival in Rats

    PubMed Central

    Chehelcheraghi, Farzaneh; Eimani, Hossein; Homayoonsadraie, Seyed; Torkaman, Giti; Amini, Abdollah; Alavi Majd, Hamid; Shemshadi, Hashem

    2016-01-01

    Background The necrotic skin flap represents a great challenge in plastic and reconstructive surgery. In this study, we evaluated the effect of bioscaffolds, acellular amniotic membranes (AAMs), and bone marrow-derived mesenchymal stem cells (BM-MSCs) on random skin flap (RSF) survival in rats by applying a cell-free extracellular matrix scaffold as a supportive component for the growth and proliferation of BM-MSCs on RSFs. AAM matrix scaffolds were created by incubating AMs in ethylenediaminetetraacetic acid 0.05% at 37°C, and cell scrapers were used. Objectives The aim of the present study was to assess the effect of AAM as a scaffold in TE, and combined with transplanted BM-MSCs, on the survival of RSFs and on the biomechanical parameters of the incision-wound flap margins 7 days after flap elevation. Materials and Methods BM-MSCs and AAMs were transplanted into subcutaneous tissue in the flap area. On the 7th postoperative day, the surviving flap areas were measured using digital imaging software, and the flap tissue was collected for evaluation. Forty rats were randomly divided into four groups of 10 each: group 1 received an AAM injection; group 2 underwent BM-MSC transplantation; group 3 received both AAM injection + BM-MSC transplantation; and group 4 was the control group, receiving only saline. Results The survival area in the AAM/BM-MSC group was significantly higher than in the control group (18.49 ± 1.58 versus 7.51 ± 2.42, P < 0.05). The biomechanical assessment showed no significant differences between the experimental groups and the control group (P > 0.05), and there was no correlation with flap survival. Conclusions Our findings showed that the treatment of flaps with BM-MSC and AAM transplantations significantly promoted flap survival compared to a control group. The viability of the flap was improved by combining BM-MSCs with AAM matrix scaffolds. PMID:27621924

  5. Acellular Dermal Matrix in Rotator Cuff Surgery.

    PubMed

    Cooper, Joseph; Mirzayan, Raffy

    2016-01-01

    The success of rotator cuff repair (RCR) surgery can be measured clinically (validated outcome scores, range of motion) as well as structurally (re-tear rates using imaging studies). Regardless of repair type or technique, most studies have shown that patients do well clinically. However, multiple studies have also shown that structurally, the failure rate can be very high. A variety of factors, including poor tendon quality, age over 63 years, smoking, advanced fatty infiltration into the muscle, and the inability of the tendon to heal to bone, have been implicated as the cause of the high re-tear rate in RCRs. The suture-tendon interface is felt to be the weakest link in the RCR construct, and suture pullout through the tendon is believed to be the most common method of failure. This review of the published literature seeks to determine if there is support for augmentation of RCR with acellular dermal matrices to strengthen the suture-tendon interface and reduce the re-tear rate. PMID:27552454

  6. Evaluation of lymphangiogenesis in acellular dermal matrix

    PubMed Central

    Cherubino, Mario; Pellegatta, Igor; Tamborini, Federico; Cerati, Michele; Sessa, Fausto; Valdatta, Luigi

    2014-01-01

    Introduction: Much attention has been directed towards understanding the phenomena of angiogenesis and lymphangiogenesis in wound healing. Thanks to the manifold dermal substitute available nowadays, wound treatment has improved greatly. Many studies have been published about angiogenesis and cell invasion in INTEGRA®. On the other hand, the development of the lymphatic network in acellular dermal matrix (ADM) is a more obscure matter. In this article, we aim to characterize the different phases of host cell invasion in ADM. Special attention was given to lymphangiogenic aspects. Materials and Methods: Among 57 rats selected to analyse the role of ADM in lymphangiogenesis, we created four groups. We performed an excision procedure on both thighs of these rats: On the left one we did not perform any action except repairing the borders of the wound; while on the right one we used INTEGRA® implant. The excision biopsy was performed at four different times: First group after 7 days, second after 14 days, third after 21 days and fourth after 28 days. For our microscopic evaluation, we used the classical staining technique of haematoxylin and eosin and a semi-quantitative method in order to evaluate cellularity counts. To assess angiogenesis and lymphangiogenesis development we employed PROX-1 Ab and CD31/PECAM for immunohistochemical analysis. Results: We found remarkable wound contraction in defects that healed by secondary intention while minor wound contraction was observed in defects treated with ADM. At day 7, optical microscopy revealed a more plentiful cellularity in the granulation tissue compared with the dermal regeneration matrix. The immunohistochemical process highlighted vascular and lymphatic cells in both groups. After 14 days a high grade of fibrosis was noticeable in the non-treated group. At day 21, both lymphatic and vascular endothelial cells were better developed in the group with a dermal matrix application. At day 28, lymphatic endothelial

  7. Acellular dermal matrix in abdominal wall reconstruction.

    PubMed

    Silverman, Ronald P

    2011-09-01

    Abdominal wall reconstruction is a complex and challenging surgical undertaking. While permanent prosthetic mesh is considered the gold standard for minimizing hernia recurrence, placement of synthetic mesh is sometimes imprudent due to contamination or risk of infection. Acellular dermal matrices (ADM) offer an exciting biologic alternative. This article provides a historical perspective on the evolution of complex ventral hernia repair leading up to and including the placement of ADM, an explanation of the biology of ADM as it relates to ventral hernia repair, and a description of the current indications, techniques, benefits, and shortcomings of its use in the abdominal wall.

  8. Infection in the Nasal Tip Caused by Acellular Dermal Matrix.

    PubMed

    Lee, Kun Hee

    2015-12-01

    A 19-year-old female patient visited our clinic for rhinoplasty. She complained about her low take-off point, which was apparent in profile view, and wanted slight tip projection. She refused additional cartilage harvesting from ears or ribs but consented to the use of homologous tissue, including acellular dermal matrix, for her dorsum and tip. Septoturbinoplasty was performed, and only a very small amount of septal cartilage could be harvested. It was used as both the columellar strut and the alar rim graft. Nasal dorsum and tip were augmented with acellular dermal matrix. Three months postoperatively, she experienced a few episodes of edema and redness on her nasal tip, followed by pus exudation from the nasal skin. Six months postoperatively, she underwent revision rhinoplasty for removal of inflamed grafts, and onlay tip graft with homologous rib cartilage was performed. Nasal dorsum or tip grafts are an integral part of Asian rhinoplasty. Autogenous tissue is the gold standard for grafting materials. However, the limited availability of autogenous tissue and the preference of patients and surgeons for artificial surgical implants make Asian rhinoplasty challenging. Unavailability of autogenous cartilage and patient refusal of artificial implants led to the use of acellular dermal matrix (ADM) in the nasal dorsum and tip for this case. This is the first report of postoperative complication because of infection rather than absorption after ADM use.

  9. Infection in the Nasal Tip Caused by Acellular Dermal Matrix.

    PubMed

    Lee, Kun Hee

    2015-12-01

    A 19-year-old female patient visited our clinic for rhinoplasty. She complained about her low take-off point, which was apparent in profile view, and wanted slight tip projection. She refused additional cartilage harvesting from ears or ribs but consented to the use of homologous tissue, including acellular dermal matrix, for her dorsum and tip. Septoturbinoplasty was performed, and only a very small amount of septal cartilage could be harvested. It was used as both the columellar strut and the alar rim graft. Nasal dorsum and tip were augmented with acellular dermal matrix. Three months postoperatively, she experienced a few episodes of edema and redness on her nasal tip, followed by pus exudation from the nasal skin. Six months postoperatively, she underwent revision rhinoplasty for removal of inflamed grafts, and onlay tip graft with homologous rib cartilage was performed. Nasal dorsum or tip grafts are an integral part of Asian rhinoplasty. Autogenous tissue is the gold standard for grafting materials. However, the limited availability of autogenous tissue and the preference of patients and surgeons for artificial surgical implants make Asian rhinoplasty challenging. Unavailability of autogenous cartilage and patient refusal of artificial implants led to the use of acellular dermal matrix (ADM) in the nasal dorsum and tip for this case. This is the first report of postoperative complication because of infection rather than absorption after ADM use. PMID:26894006

  10. BIOCOMPATIBILITY OF ACELLULAR DERMAL MATRIX GRAFT EVALUATED IN CULTURE OF MURINE MACROPHAGES

    PubMed Central

    Vendramini, Ana Paula; Melo, Rafaela Fernanda; Marcantonio, Rosemary Adriana Chiérici; Carlos, Iracilda Zepone

    2006-01-01

    The acellular dermal matrix allograft has been used as an alternative to autogenous palatal mucosal graft. The aim of this study was the evaluation of the biocompatibility of an acellular dermal matrix (AlloDerm®) in culture of macrophages. For hydrogen peroxidase determination we used the method of Pick & Kesari, and the Griess method for nitric oxide determination,. Statistical analysis showed no significant difference (p ≤ 0,05) in the release of nitric oxide and hydrogen peroxide by the macrophages exposed to acellular dermal matrix and the negative control. The results suggest that acellular dermal matrix did not activate the cell inflammatory response. PMID:19089033

  11. Human acellular dermal wound matrix: evidence and experience.

    PubMed

    Kirsner, Robert S; Bohn, Greg; Driver, Vickie R; Mills, Joseph L; Nanney, Lillian B; Williams, Marie L; Wu, Stephanie C

    2015-12-01

    A chronic wound fails to complete an orderly and timely reparative process and places patients at increased risk for wound complications that negatively impact quality of life and require greater health care expenditure. The role of extracellular matrix (ECM) is critical in normal and chronic wound repair. Not only is ECM the largest component of the dermal skin layer, but also ECM proteins provide structure and cell signalling that are necessary for successful tissue repair. Chronic wounds are characterised by their inflammatory and proteolytic environment, which degrades the ECM. Human acellular dermal matrices, which provide an ECM scaffold, therefore, are being used to treat chronic wounds. The ideal human acellular dermal wound matrix (HADWM) would support regenerative healing, providing a structure that could be repopulated by the body's cells. Experienced wound care investigators and clinicians discussed the function of ECM, the evidence related to a specific HADWM (Graftjacket(®) regenerative tissue matrix, Wright Medical Technology, Inc., licensed by KCI USA, Inc., San Antonio, TX), and their clinical experience with this scaffold. This article distills these discussions into an evidence-based and practical overview for treating chronic lower extremity wounds with this HADWM. PMID:24283346

  12. Human acellular dermal wound matrix: evidence and experience.

    PubMed

    Kirsner, Robert S; Bohn, Greg; Driver, Vickie R; Mills, Joseph L; Nanney, Lillian B; Williams, Marie L; Wu, Stephanie C

    2015-12-01

    A chronic wound fails to complete an orderly and timely reparative process and places patients at increased risk for wound complications that negatively impact quality of life and require greater health care expenditure. The role of extracellular matrix (ECM) is critical in normal and chronic wound repair. Not only is ECM the largest component of the dermal skin layer, but also ECM proteins provide structure and cell signalling that are necessary for successful tissue repair. Chronic wounds are characterised by their inflammatory and proteolytic environment, which degrades the ECM. Human acellular dermal matrices, which provide an ECM scaffold, therefore, are being used to treat chronic wounds. The ideal human acellular dermal wound matrix (HADWM) would support regenerative healing, providing a structure that could be repopulated by the body's cells. Experienced wound care investigators and clinicians discussed the function of ECM, the evidence related to a specific HADWM (Graftjacket(®) regenerative tissue matrix, Wright Medical Technology, Inc., licensed by KCI USA, Inc., San Antonio, TX), and their clinical experience with this scaffold. This article distills these discussions into an evidence-based and practical overview for treating chronic lower extremity wounds with this HADWM.

  13. Multilayered implantation using acellular dermal matrix into nude mice.

    PubMed

    Lee, Dong Won; Lee, Myung Chul; Roh, Hyun; Lee, Won Jai

    2014-12-01

    Soft tissue augmentation using acellular dermal matrix has gained popularity to overcome the shortcomings of autogenous and alloplastic materials. Sometimes it needs multilayered stacking to obtain enough volume. In this study, we investigated the efficacy of multilayered implantation using acellular dermal matrix (MatriDerm(®)) for soft tissue augmentation. MatriDerm was implanted subdermally on each side of the dorsum of nude mice (n = 20), stacked two layers thick in the control group and three layers thick in the experimental group. Alterations of thickness, degree of angiogenesis, and collagen and elastin fiber syntheses were observed over 40 days. Three-layered implantation with MatriDerm maintained its volume similarly as in two-layered implantation, although the thickness decreased after 30 days in both groups. At the early stage of implantation, angiogenesis and collagen and elastin fiber syntheses occurred fluently on the central portion, which is the farthest away from the surface in contact with the host tissue. Collagen and elastin fibers became more concentrated over time, and the original structure of MatriDerm could not be maintained due to being replaced with newly formed collagen and elastin fibers 40 days after implantation. Multilayered implantation with MatriDerm is considered appropriate for tissue ingrowth and can be used as a substitute for soft tissue augmentation.

  14. Differentiation of mesenchymal stem cells into neuronal cells on fetal bovine acellular dermal matrix as a tissue engineered nerve scaffold.

    PubMed

    Feng, Yuping; Wang, Jiao; Ling, Shixin; Li, Zhuo; Li, Mingsheng; Li, Qiongyi; Ma, Zongren; Yu, Sijiu

    2014-11-15

    The purpose of this study was to assess fetal bovine acellular dermal matrix as a scaffold for supporting the differentiation of bone marrow mesenchymal stem cells into neural cells following induction with neural differentiation medium. We performed long-term, continuous observation of cell morphology, growth, differentiation, and neuronal development using several microscopy techniques in conjunction with immunohistochemistry. We examined specific neuronal proteins and Nissl bodies involved in the differentiation process in order to determine the neuronal differentiation of bone marrow mesenchymal stem cells. The results show that bone marrow mesenchymal stem cells that differentiate on fetal bovine acellular dermal matrix display neuronal morphology with unipolar and bi/multipolar neurite elongations that express neuronal-specific proteins, including βIII tubulin. The bone marrow mesenchymal stem cells grown on fetal bovine acellular dermal matrix and induced for long periods of time with neural differentiation medium differentiated into a multilayered neural network-like structure with long nerve fibers that was composed of several parallel microfibers and neuronal cells, forming a complete neural circuit with dendrite-dendrite to axon-dendrite to dendrite-axon synapses. In addition, growth cones with filopodia were observed using scanning electron microscopy. Paraffin sectioning showed differentiated bone marrow mesenchymal stem cells with the typical features of neuronal phenotype, such as a large, round nucleus and a cytoplasm full of Nissl bodies. The data suggest that the biological scaffold fetal bovine acellular dermal matrix is capable of supporting human bone marrow mesenchymal stem cell differentiation into functional neurons and the subsequent formation of tissue engineered nerve.

  15. Porcine acellular lung matrix for wound healing and abdominal wall reconstruction: A pilot study.

    PubMed

    Fernandez-Moure, Joseph S; Van Eps, Jeffrey L; Rhudy, Jessica R; Cabrera, Fernando J; Acharya, Ghanashyam S; Tasciotti, Ennio; Sakamoto, Jason; Nichols, Joan E

    2016-01-01

    Surgical wound healing applications require bioprosthetics that promote cellular infiltration and vessel formation, metrics associated with increased mechanical strength and resistance to infection. Porcine acellular lung matrix is a novel tissue scaffold known to promote cell adherence while minimizing inflammatory reactions. In this study, we evaluate the capacity of porcine acellular lung matrix to sustain cellularization and neovascularization in a rat model of subcutaneous implantation and chronic hernia repair. We hypothesize that, compared to human acellular dermal matrix, porcine acellular lung matrix would promote greater cell infiltration and vessel formation. Following pneumonectomy, porcine lungs were processed and characterized histologically and by scanning electron microscopy to demonstrate efficacy of the decellularization. Using a rat model of subcutaneou implantation, porcine acellular lung matrices (n = 8) and human acellular dermal matrices (n = 8) were incubated in vivo for 6 weeks. To evaluate performance under mechanically stressed conditions, porcine acellular lung matrices (n = 7) and human acellular dermal matrices (n = 7) were implanted in a rat model of chronic ventral incisional hernia repair for 6 weeks. After 6 weeks, tissues were evaluated using hematoxylin and eosin and Masson's trichrome staining to quantify cell infiltration and vessel formation. Porcine acellular lung matrices were shown to be successfully decellularized. Following subcutaneous implantation, macroscopic vessel formation was evident. Porcine acellular lung matrices demonstrated sufficient incorporation and showed no evidence of mechanical failure after ventral hernia repair. Porcine acellular lung matrices demonstrated significantly greater cellular density and vessel formation when compared to human acellular dermal matrix. Vessel sizes were similar across all groups. Cell infiltration and vessel formation are well-characterized metrics of incorporation

  16. Porcine acellular lung matrix for wound healing and abdominal wall reconstruction: A pilot study

    PubMed Central

    Fernandez-Moure, Joseph S; Van Eps, Jeffrey L; Rhudy, Jessica R; Cabrera, Fernando J; Acharya, Ghanashyam S; Tasciotti, Ennio; Sakamoto, Jason; Nichols, Joan E

    2016-01-01

    Surgical wound healing applications require bioprosthetics that promote cellular infiltration and vessel formation, metrics associated with increased mechanical strength and resistance to infection. Porcine acellular lung matrix is a novel tissue scaffold known to promote cell adherence while minimizing inflammatory reactions. In this study, we evaluate the capacity of porcine acellular lung matrix to sustain cellularization and neovascularization in a rat model of subcutaneous implantation and chronic hernia repair. We hypothesize that, compared to human acellular dermal matrix, porcine acellular lung matrix would promote greater cell infiltration and vessel formation. Following pneumonectomy, porcine lungs were processed and characterized histologically and by scanning electron microscopy to demonstrate efficacy of the decellularization. Using a rat model of subcutaneou implantation, porcine acellular lung matrices (n = 8) and human acellular dermal matrices (n = 8) were incubated in vivo for 6 weeks. To evaluate performance under mechanically stressed conditions, porcine acellular lung matrices (n = 7) and human acellular dermal matrices (n = 7) were implanted in a rat model of chronic ventral incisional hernia repair for 6 weeks. After 6 weeks, tissues were evaluated using hematoxylin and eosin and Masson’s trichrome staining to quantify cell infiltration and vessel formation. Porcine acellular lung matrices were shown to be successfully decellularized. Following subcutaneous implantation, macroscopic vessel formation was evident. Porcine acellular lung matrices demonstrated sufficient incorporation and showed no evidence of mechanical failure after ventral hernia repair. Porcine acellular lung matrices demonstrated significantly greater cellular density and vessel formation when compared to human acellular dermal matrix. Vessel sizes were similar across all groups. Cell infiltration and vessel formation are well-characterized metrics of incorporation

  17. The effects of acellular amniotic membrane matrix on osteogenic differentiation and ERK1/2 signaling in human dental apical papilla cells.

    PubMed

    Chen, Yi-Jane; Chung, Min-Chun; Jane Yao, Chung-Chen; Huang, Chien-Hsun; Chang, Hao-Hueng; Jeng, Jiiang-Huei; Young, Tai-Horng

    2012-01-01

    The amniotic membrane (AM) has been widely used in the field of tissue engineering because of the favorable biological properties for scaffolding material. However, little is known about the effects of an acellular AM matrix on the osteogenic differentiation of mesenchymal stem cells. In this study, it was found that both basement membrane side and collagenous stroma side of the acellular AM matrix were capable of providing a preferential environment for driving the osteogenic differentiation of human dental apical papilla cells (APCs) with proven stem cell characteristics. Acellular AM matrix potentiated the induction effect of osteogenic supplements (OS) such as ascorbic acid, β-glycerophosphate, and dexamethasone and enhanced the osteogenic differentiation of APCs, as seen by increased core-binding factor alpha 1 (Cbfa-1) phosphorylation, alkaline phosphatase activity, mRNA expression of osteogenic marker genes, and mineralized matrix deposition. Even in the absence of soluble OS, acellular AM matrix also could exert the substrate-induced effect on initiating APCs' differentiation. Especially, the collagenous stroma side was more effective than the basement membrane side. Moreover, the AM-induced effect was significantly inhibited by U0126, an inhibitor of extracellular signaling-regulated kinase 1/2 (ERK1/2) signaling. Taken together, the osteogenic differentiation promoting effect on APCs is AM-specific, which provides potential applications of acellular AM matrix in bone/tooth tissue engineering.

  18. Distinctive expression of extracellular matrix molecules at mRNA and protein levels during formation of cellular and acellular cementum in the rat.

    PubMed

    Sasano, Y; Maruya, Y; Sato, H; Zhu, J X; Takahashi, I; Mizoguchi, I; Kagayama, M

    2001-02-01

    Little is known about differential expression of extracellular matrices secreted by cementoblasts between cellular and acellular cementum. We hypothesize that cementoblasts lining acellular cementum express extracellular matrix genes differently from those lining cellular cementum, thereby forming two distinct types of extracellular matrices. To test this hypothesis, we investigated spatial and temporal gene expression of selected extracellular matrix molecules, that is type I collagen, bone sialoprotein, osteocalcin and osteopontin, during formation of both cellular and acellular cementum using in situ hybridization. In addition, their extracellularly deposited and accumulated proteins were examined immunohistochemically. The mRNA transcripts of pro-alpha1 (I) collagen were primarily localized in cementoblasts of cellular cementum and cementocytes, while those of bone sialoprotein were predominantly seen in cementoblasts lining acellular cementum. In contrast, osteocalcin was expressed by both types of cementoblasts and cementocytes and so was osteopontin but only transiently. Our immunohistochemical examination revealed that translated proteins were localized extracellularly where the genes had been expressed intracellularly. The present study demonstrated the distinctive expression of genes and proteins of the extracellular matrix molecules between cellular and acellular cementum. PMID:11432645

  19. Development and Characterization of Acellular Extracellular Matrix Scaffolds from Porcine Menisci for Use in Cartilage Tissue Engineering

    PubMed Central

    Chen, Ying-Chen; Chen, Ray-Neng; Jhan, Hua-Jing; Liu, Der-Zen; Ho, Hsiu-O; Mao, Yong; Kohn, Joachim

    2015-01-01

    Given the growing number of arthritis patients and the limitations of current treatments, there is great urgency to explore cartilage substitutes by tissue engineering. In this study, we developed a novel decellularization method for menisci to prepare acellular extracellular matrix (ECM) scaffolds with minimal adverse effects on the ECM. Among all the acid treatments, formic acid treatment removed most of the cellular contents and preserved the highest ECM contents in the decellularized porcine menisci. Compared with fresh porcine menisci, the content of DNA decreased to 4.10%±0.03%, and there was no significant damage to glycosaminoglycan (GAG) or collagen. Histological staining also confirmed the presence of ECM and the absence of cellularity. In addition, a highly hydrophilic scaffold with three-dimensional interconnected porous structure was fabricated from decellularized menisci tissue. Human chondrocytes showed enhanced cell proliferation and synthesis of chondrocyte ECM including type II collagen and GAG when cultured in this acellular scaffold. Moreover, the scaffold effectively supported chondrogenesis of human bone marrow-derived mesenchymal stem cells. Finally, in vivo implantation was conducted in rats to assess the biocompatibility of the scaffolds. No significant inflammatory response was observed. The acellular ECM scaffold provided a native environment for cells with diverse physiological functions to promote cell proliferation and new tissue formation. This study reported a novel way to prepare decellularized meniscus tissue and demonstrated the potential as scaffolds to support cartilage repair. PMID:25919905

  20. Development and Characterization of Acellular Extracellular Matrix Scaffolds from Porcine Menisci for Use in Cartilage Tissue Engineering.

    PubMed

    Chen, Ying-Chen; Chen, Ray-Neng; Jhan, Hua-Jing; Liu, Der-Zen; Ho, Hsiu-O; Mao, Yong; Kohn, Joachim; Sheu, Ming-Thau

    2015-09-01

    Given the growing number of arthritis patients and the limitations of current treatments, there is great urgency to explore cartilage substitutes by tissue engineering. In this study, we developed a novel decellularization method for menisci to prepare acellular extracellular matrix (ECM) scaffolds with minimal adverse effects on the ECM. Among all the acid treatments, formic acid treatment removed most of the cellular contents and preserved the highest ECM contents in the decellularized porcine menisci. Compared with fresh porcine menisci, the content of DNA decreased to 4.10%±0.03%, and there was no significant damage to glycosaminoglycan (GAG) or collagen. Histological staining also confirmed the presence of ECM and the absence of cellularity. In addition, a highly hydrophilic scaffold with three-dimensional interconnected porous structure was fabricated from decellularized menisci tissue. Human chondrocytes showed enhanced cell proliferation and synthesis of chondrocyte ECM including type II collagen and GAG when cultured in this acellular scaffold. Moreover, the scaffold effectively supported chondrogenesis of human bone marrow-derived mesenchymal stem cells. Finally, in vivo implantation was conducted in rats to assess the biocompatibility of the scaffolds. No significant inflammatory response was observed. The acellular ECM scaffold provided a native environment for cells with diverse physiological functions to promote cell proliferation and new tissue formation. This study reported a novel way to prepare decellularized meniscus tissue and demonstrated the potential as scaffolds to support cartilage repair. PMID:25919905

  1. Repair of a Gingival Fenestration Using an Acellular Dermal Matrix Allograft.

    PubMed

    Breault, Lawrence G; Brentson, Raquel C; Fowler, Edward B; Bisch, Frederick C

    2016-01-01

    A case report illustrating the successful treatment of a gingival fenestration with an acellular dermal matrix (ADM) allograft. After 2½ months of healing, the ADM was completely integrated into the soft tissues of the mandibular anterior gingiva with complete resolution of the gingival fenestration, resulting in excellent gingival esthetics. PMID:26874103

  2. Coverage of gingival recession defects using acellular dermal matrix allograft with or without beta-tricalcium phosphate.

    PubMed

    Okubo, Nobuki; Fujita, Takahisa; Ishii, Yoshihito; Ota, Mikio; Shibukawa, Yoshihiro; Yamada, Satoru

    2013-01-01

    The aim of this study was to investigate the effect of beta-tricalcium phosphate (β-TCP) particles in combination with acellular dermal matrix (ADM) allograft in gingival recession. Experimental gingival recession defects were created in beagle dogs and randomly assigned to one of the following groups: ADM, ADM + β-TCP, or coronally positioned flap (CPF; control). Tissues were histologically examined at 4, 8, or 16 weeks following treatment. A greater thickness of gingiva was observed at the sites treated in both the ADM + β-TCP and ADM groups than in the CPF group. The ADM + β-TCP group showed a statistically significant increase in both new bone and cementum formations compared to the ADM group. The results suggest that the combination of β-TCP and ADM is more effective in promoting new bone and cementum formations than ADM graft alone. PMID:21862508

  3. A new candidate substrate for cell-matrix adhesion study: the acellular human amniotic matrix.

    PubMed

    Guo, Qianchen; Lu, Xuya; Xue, Yuan; Zheng, Hong; Zhao, Xiaotao; Zhao, Huajian

    2012-01-01

    In vivo adhesions between cells and the extracellular matrix play a crucial role in cell differentiation, proliferation, and migration as well as tissue remodeling. Natural three-dimensional (3D) matrices, such as self-assembling matrices and Matrigel, have limitations in terms of their biomechanical properties. Here, we present a simple method to produce an acellular human amniotic matrix (AHAM) with preserved biomechanical properties and a favorable adhesion potential. On the stromal side of the AHAM, human foreskin fibroblasts (HFFs) attached and extended with bipolar spindle-shaped morphology proliferated to multilayer networks, invaded into the AHAM, and migrated in a straight line. Moreover, αV integrin, paxillin, and fibronectin were observed to colocalize after 24 h of HFF culture on the stromal side of the AHAM. Our results indicate that the AHAM may be an ideal candidate as a cell-matrix adhesion substrate to study cell adhesion and invasion as well as other functions in vitro under a tensile force that mimics the in vivo environment.

  4. Chondrogenesis of Human Infrapatellar Fat Pad Stem Cells on Acellular Dermal Matrix.

    PubMed

    Ye, Ken; Traianedes, Kathy; Choong, Peter F M; Myers, Damian E

    2016-01-01

    Acellular dermal matrix (ADM) has been in clinical use for decades in numerous surgical applications. The ability for ADM to promote cellular repopulation, revascularisation and tissue regeneration is well documented. Adipose stem cells have the ability to differentiate into mesenchymal tissue types, including bone and cartilage. The aim of this study was to investigate the potential interaction between ADM and adipose stem cells in vitro using TGFβ3 and BMP6. Human infrapatellar fat pad-derived adipose stem cells (IPFP-ASC) were cultured with ADM derived from rat dermis in chondrogenic (TGFβ3 and BMP6) medium in vitro for 2 and 4 weeks. Histology, qPCR, and immunohistochemistry were performed to assess for markers of chondrogenesis (collagen Type II, SOX9 and proteoglycans). At 4 weeks, cell-scaffold constructs displayed cellular changes consistent with chondrogenesis, with evidence of stratification of cell layers and development of a hyaline-like cartilage layer superficially, which stained positively for collagen Type II and proteoglycans. Significant cell-matrix interaction was seen between the cartilage layer and the ADM itself with seamless integration between each layer. Real time qPCR showed significantly increased COL2A1, SOX9, and ACAN gene expression over 4 weeks when compared to control. COL1A2 gene expression remained unchanged over 4 weeks. We believe that the principles that make ADM versatile and successful for tissue regeneration are applicable to cartilage regeneration. This study demonstrates in vitro the ability for IPFP-ASCs to undergo chondrogenesis, infiltrate, and interact with ADM. These outcomes serve as a platform for in vivo modelling of ADM for cartilage repair. PMID:26858950

  5. Chondrogenesis of Human Infrapatellar Fat Pad Stem Cells on Acellular Dermal Matrix

    PubMed Central

    Ye, Ken; Traianedes, Kathy; Choong, Peter F. M.; Myers, Damian E.

    2016-01-01

    Acellular dermal matrix (ADM) has been in clinical use for decades in numerous surgical applications. The ability for ADM to promote cellular repopulation, revascularisation and tissue regeneration is well documented. Adipose stem cells have the ability to differentiate into mesenchymal tissue types, including bone and cartilage. The aim of this study was to investigate the potential interaction between ADM and adipose stem cells in vitro using TGFβ3 and BMP6. Human infrapatellar fat pad-derived adipose stem cells (IPFP-ASC) were cultured with ADM derived from rat dermis in chondrogenic (TGFβ3 and BMP6) medium in vitro for 2 and 4 weeks. Histology, qPCR, and immunohistochemistry were performed to assess for markers of chondrogenesis (collagen Type II, SOX9 and proteoglycans). At 4 weeks, cell-scaffold constructs displayed cellular changes consistent with chondrogenesis, with evidence of stratification of cell layers and development of a hyaline-like cartilage layer superficially, which stained positively for collagen Type II and proteoglycans. Significant cell–matrix interaction was seen between the cartilage layer and the ADM itself with seamless integration between each layer. Real time qPCR showed significantly increased COL2A1, SOX9, and ACAN gene expression over 4 weeks when compared to control. COL1A2 gene expression remained unchanged over 4 weeks. We believe that the principles that make ADM versatile and successful for tissue regeneration are applicable to cartilage regeneration. This study demonstrates in vitro the ability for IPFP-ASCs to undergo chondrogenesis, infiltrate, and interact with ADM. These outcomes serve as a platform for in vivo modelling of ADM for cartilage repair. PMID:26858950

  6. Chondrogenesis of Human Infrapatellar Fat Pad Stem Cells on Acellular Dermal Matrix.

    PubMed

    Ye, Ken; Traianedes, Kathy; Choong, Peter F M; Myers, Damian E

    2016-01-01

    Acellular dermal matrix (ADM) has been in clinical use for decades in numerous surgical applications. The ability for ADM to promote cellular repopulation, revascularisation and tissue regeneration is well documented. Adipose stem cells have the ability to differentiate into mesenchymal tissue types, including bone and cartilage. The aim of this study was to investigate the potential interaction between ADM and adipose stem cells in vitro using TGFβ3 and BMP6. Human infrapatellar fat pad-derived adipose stem cells (IPFP-ASC) were cultured with ADM derived from rat dermis in chondrogenic (TGFβ3 and BMP6) medium in vitro for 2 and 4 weeks. Histology, qPCR, and immunohistochemistry were performed to assess for markers of chondrogenesis (collagen Type II, SOX9 and proteoglycans). At 4 weeks, cell-scaffold constructs displayed cellular changes consistent with chondrogenesis, with evidence of stratification of cell layers and development of a hyaline-like cartilage layer superficially, which stained positively for collagen Type II and proteoglycans. Significant cell-matrix interaction was seen between the cartilage layer and the ADM itself with seamless integration between each layer. Real time qPCR showed significantly increased COL2A1, SOX9, and ACAN gene expression over 4 weeks when compared to control. COL1A2 gene expression remained unchanged over 4 weeks. We believe that the principles that make ADM versatile and successful for tissue regeneration are applicable to cartilage regeneration. This study demonstrates in vitro the ability for IPFP-ASCs to undergo chondrogenesis, infiltrate, and interact with ADM. These outcomes serve as a platform for in vivo modelling of ADM for cartilage repair.

  7. DermACELL: Human Acellular Dermal Matrix Allograft A Case Report.

    PubMed

    Cole, Windy E

    2016-03-01

    Diabetes often causes ulcers on the feet of diabetic patients. A 56-year-old, insulin-dependent, diabetic woman presented to the wound care center with a Wagner grade 3 ulcer of the right heel. She reported a 3-week history of ulceration with moderate drainage and odor and had a history of ulceration and osteomyelitis in the contralateral limb. Rigorous wound care, including hospitalization; surgical incision and drainage; intravenous antibiotic drug therapy; vacuum-assisted therapy; and a new room temperature, sterile, human acellular dermal matrix graft were used to heal the wound, save her limb, and restore her activities of daily living. This case presentation involves alternative treatment of a diabetic foot ulcer with this new acellular dermal matrix, DermACELL. PMID:27031550

  8. Pioneering technique using Acellular Dermal Matrix in the rescue of a radiation ulcer

    PubMed Central

    NASEEM, S.; PATEL, A.D.; DEVALIA, H.

    2016-01-01

    Background Radiotherapy as an adjuvant to mastectomy is integral to the treatment of breast cancer, but can result in skin ulceration. Skin ulceration following radiotherapy is traditionally managed by removing the implant and allowing the skin to heal by secondary intention. Case report A 42-year-old woman underwent radiotherapy following a breast reconstruction. She developed a 2 x 3cm radiation ulcer. The ulcer was managed by removing the implant and performing capsulectomy. A Beckers 50 expander was placed and reinforced with acellular dermal matrix inferolaterally. At follow-up the patient had a good cosmetic outcome. Conclusion Post-radiation skin ulcers present a challenge to treat with no current standardised management. The use of acellular dermal matrix may present a new technique to promote healing in these testing cases. PMID:27142826

  9. Effective management of major lower extremity wounds using an acellular regenerative tissue matrix: a pilot study.

    PubMed

    Brigido, Stephen A; Boc, Steven F; Lopez, Ramon C

    2004-01-01

    Wound healing is a significant problem in orthopedics. Graftjacket tissue matrix (Wright Medical Technology, Inc, Arlington, Tenn), a novel acellular regenerative tissue matrix, has been designed to aid wound closure. A prospective, randomized study was initiated to determine the efficacy of this tissue product in wound repair compared with conventional treatment. Lower extremity wounds are refractile to healing in patients with diabetes mellitus. Therefore, researchers used diabetic foot ulcers to evaluate the efficacy of GraftJacket tissue matrix in wound repair. Only a single administration of the tissue matrix was required. After 1 month of treatment, preliminary results demonstrate that this novel tissue matrix promotes faster healing at a statistically significant rate over conventional treatment. Because wounds in this series of patients are deep and circulation around the wound is poor, the preliminary results suggest that this tissue matrix will be applicable to other types of orthopedic wounds.

  10. Root Coverage in Smokers with Acellular Dermal Matrix Graft and Enamel Matrix Derivative: A 12-Month Randomized Clinical Trial.

    PubMed

    Costa, Priscila Paganini; Alves, Luciana Bastos; Souza, Sérgio Luís; Grisi, Márcio Fernando; Palioto, Daniela Bazan; Taba, Mario; Novaes, Arthur Belém

    2016-01-01

    This study investigated whether enamel matrix derivative (EMD) contributes to root coverage of gingival recessions performed with acellular dermal matrix graft (ADMG) in smokers during a 12-month follow-up. A sample of 19 smokers presenting bilateral Miller Class I or II gingival recessions were included. Selected sites randomly received both ADMG and EMD (test) or ADMG alone (control). Probing depth, clinical attachment level, gingival recession height, keratinized tissue, and root coverage were evaluated. Mean gain in recession height (P < .05), sites with complete root coverage (P < .05), and percentage of root coverage (59.7% and 52.8%, respectively) favored the test group compared with the control group. PMID:27333010

  11. Florid pustular dermatitis of breast: A case report on a unusual complication from acellular dermal matrix use

    PubMed Central

    James, Justin; Jackson, Lee; Saunders, Christobel

    2016-01-01

    Introduction Idiopathic erythematous reaction of the breast (Red breast syndrome) is a known complication following breast reconstruction with acellular dermal matrix. However pustular dermatitis like presentation is not previously known. Presentation of case We present a 42-year-old lady who developed bilateral pustular dermatitis like appearance following breast reconstruction with acellular dermal matrix slings. Though surgical washout was done, both expanders and flex HD could be preserved. Discussion Acellular dermal matrix use is the only possible explanation for such a presentation and this can be considered a variant of red breast syndrome. Conclusion Pustular dermatitis like presentation can be associated with acelluar dermal matrix use and should be considered in similar clinical presentations, since this can avoid unnecessary surgical procedures. PMID:27058152

  12. Current opinions on indications and algorithms for acellular dermal matrix use in primary prosthetic breast reconstruction.

    PubMed

    Vu, Michael M; Kim, John Y S

    2015-06-01

    Acellular dermal matrix (ADM) is widely used in primary prosthetic breast reconstruction. Many indications and contraindications to use ADM have been reported in the literature, and their use varies by institution and surgeon. Developing rational, tested algorithms to determine when ADM is appropriate can significantly improve surgical outcomes and reduce costs associated with ADM use. We review the important indications and contraindications, and discuss the algorithms that have been put forth so far. Further research into algorithmic decision-making for ADM use will allow optimized balancing of cost with risk and benefit. PMID:26161304

  13. Current opinions on indications and algorithms for acellular dermal matrix use in primary prosthetic breast reconstruction

    PubMed Central

    Vu, Michael M.

    2015-01-01

    Acellular dermal matrix (ADM) is widely used in primary prosthetic breast reconstruction. Many indications and contraindications to use ADM have been reported in the literature, and their use varies by institution and surgeon. Developing rational, tested algorithms to determine when ADM is appropriate can significantly improve surgical outcomes and reduce costs associated with ADM use. We review the important indications and contraindications, and discuss the algorithms that have been put forth so far. Further research into algorithmic decision-making for ADM use will allow optimized balancing of cost with risk and benefit. PMID:26161304

  14. Xenogeneic acellular conjunctiva matrix as a scaffold of tissue-engineered corneal epithelium.

    PubMed

    Zhao, Haifeng; Qu, Mingli; Wang, Yao; Wang, Zhenyu; Shi, Weiyun

    2014-01-01

    Amniotic membrane-based tissue-engineered corneal epithelium has been widely used in the reconstruction of the ocular surface. However, it often degrades too early to ensure the success of the transplanted corneal epithelium when treating patients with severe ocular surface disorders. In the present study, we investigated the preparation of xenogeneic acellular conjunctiva matrix (aCM) and evaluated its efficacy and safety as a scaffold of tissue-engineered corneal epithelium. Native porcine conjunctiva was decellularized with 0.1% sodium dodecyl sulfate (SDS) for 12 h at 37°C and sterilized via γ-irradiation. Compared with native conjunctiva, more than 92% of the DNA was removed, and more than 90% of the extracellular matrix components (glycosaminoglycan and collagen) remained after the decellularization treatment. Compared with denuded amniotic membrane (dAM), the aCM possessed favorable optical transmittance, tensile strength, stability and biocompatibility as well as stronger resistance to degradation both in vitro and in vivo. The corneal epithelial cells seeded on aCM formed a multilayered epithelial structure and endured longer than did those on dAM. The aCM-based tissue-engineered corneal epithelium was more effective in the reconstruction of the ocular surface in rabbits with limbal stem cell deficiency. These findings support the application of xenogeneic acellular conjunctiva matrix as a scaffold for reconstructing the ocular surface.

  15. Immunolocation of proteoglycans and bone-related noncollagenous glycoproteins in developing acellular cementum of rat molars.

    PubMed

    Yamamoto, T; Domon, T; Takahashi, S; Arambawatta, A K S; Wakita, M

    2004-09-01

    To elucidate the roles of proteoglycans of (PGs), bone sialoprotein (BSP), and osteopontin (OPN) in cementogenesis, their distribution was investigated in developing and established acellular cementum of rat molars by an immunoperoxidase method. To characterize PGs, antibodies against five species of glycosaminoglycans (GAGS), chondroitin-4-sulfate (C4S), chondroitin-6-sulfate (C6S), unsulfated chondroitin (C0S), dermatan sulfate (DS), and keratan sulfate (KS) were used. Routine histological staining was also applied. With onset of dentin mineralization, the initial cementum appeared on the dentin surface as a hematoxylin-stained fibril-poor layer. Subsequently, primitive principal fibers attached to the initial cementum. As the acellular cementum containing extrinsic fibers covered the initial cementum, the intal cementum formed the cemento-dentinal junction. Following immunohistochemistry at the earliest time of cementogenesis, the initial cementum was intensely immunoreactive for C4S, C6S, C0S, BSP, and OPN. After the initial cementum was embedded, neither the cemento-dentinal junction nor the cementum was immunoreactive for any GAG species. However, the cementum was immunoreactive for any GAG species. However, the cementum and cemento-dentinal were consistently immunoreactive for BSP. Although the cemento-dentinal junction was consistently immunoreactive for OPN, the remaining cementum showed no significant immunoreactivity. Thus, initial acellular cementogenesis requires a dense accumulation of PGs, BSP, and OPN, which may be associated with the mineralization process independently of collagen fibrils and initial principal fiber attachment. PMID:15278434

  16. Interposition Porcine Acellular Dermal Matrix Xenograft Successful Alternative in Treatment for Massive Rotator Cuff

    PubMed Central

    Neumann, Julie; Zgonis, Miltiadis H.; Reay, Kathleen Dolores; Mayer, Stephanie W.; Boggess, Blake; Toth, Alison P.

    2016-01-01

    Objectives: Despite advances in the surgical techniques of rotator cuff repair (RCR), the management of massive rotator cuff tears in shoulders without glenohumeral arthritis poses a difficult problem for surgeons. Failure of massive rotator cuff repairs range from 20-90% at one to two years postoperatively using arthrography, ultrasound, or magnetic resonance imaging. Additionally, there are inconsistent outcomes reported with debridement alone of massive rotator cuff tears as well as limitations seen with other current methods of operative intervention including arthroplasty and tendon transfers. The purpose of this prospective, comparative study was to determine if the repair of massive rotator cuff tears using an interposition porcine acellular dermal matrix xenograft improves subjective function, pain, range of motion, and strength at greater than two years follow-up. To our knowledge, this is the largest prospective series reporting outcomes of using porcine acellular dermal matrix xenograft as an interposition graft. Methods: Thirty-seven patients (37 shoulders) with an average age of 66 years (range 51-80 years) were prospectively followed for 33 months (range 23-48) following massive RCR using porcine acellular dermal matrix interposition xenograft. Subjective outcomes were measured using the Visual Analog Scale (VAS) pain score (0-10, 0 = no pain), Modified American Shoulder and Elbow Score (M-ASES), and Short-Form12 (SF-12) scores. Preoperative and postoperative objective outcome measures included active range of motion and supraspinatus and infraspinatus manual muscle strength. Postoperative outcome measures included quantitative muscle strength using a dynamometer and static and dynamic ultrasonography to assess the integrity of the repair. Results: Average VAS pain score decreased from 4.5 to 1.1 (P<0.001). Average postoperative M-ASES was 89.23. Average postoperative SF-12 was 52.6. Mean forward flexion, external and internal rotation significantly

  17. The acellular matrix (ACM) for bladder tissue engineering: A quantitative magnetic resonance imaging study.

    PubMed

    Cheng, Hai-Ling Margaret; Loai, Yasir; Beaumont, Marine; Farhat, Walid A

    2010-08-01

    Bladder acellular matrices (ACMs) derived from natural tissue are gaining increasing attention for their role in tissue engineering and regeneration. Unlike conventional scaffolds based on biodegradable polymers or gels, ACMs possess native biomechanical and many acquired biologic properties. Efforts to optimize ACM-based scaffolds are ongoing and would be greatly assisted by a noninvasive means to characterize scaffold properties and monitor interaction with cells. MRI is well suited to this role, but research with MRI for scaffold characterization has been limited. This study presents initial results from quantitative MRI measurements for bladder ACM characterization and investigates the effects of incorporating hyaluronic acid, a natural biomaterial useful in tissue-engineering and regeneration. Measured MR relaxation times (T(1), T(2)) and diffusion coefficient were consistent with increased water uptake and glycosaminoglycan content observed on biochemistry in hyaluronic acid ACMs. Multicomponent MRI provided greater specificity, with diffusion data showing an acellular environment and T(2) components distinguishing the separate effects of increased glycosaminoglycans and hydration. These results suggest that quantitative MRI may provide useful information on matrix composition and structure, which is valuable in guiding further development using bladder ACMs for organ regeneration and in strategies involving the use of hyaluronic acid.

  18. Low-level laser therapy promotes the osteogenic potential of adipose-derived mesenchymal stem cells seeded on an acellular dermal matrix.

    PubMed

    Choi, Kyuseok; Kang, Byung-Jae; Kim, Hyoju; Lee, Seungmin; Bae, Sohee; Kweon, Oh-Kyeong; Kim, Wan Hee

    2013-08-01

    This study investigates the feasibility of using an adipose-derived mesenchymal stem cell (ASC)-seeded acellular dermal matrix (ADM) along with low-level laser therapy (LLLT) to repair bone defect in athymic nude mice. Critical-sized calvarial defects were treated either with ADM, ADM/LLLT, ADM/ASCs, or ADM/ASCs/LLLT. In micro-computed tomography scans, the ADM/ASCs and the ADM/ASCs/LLLT groups showed remarkable bone formation after 14 days. Additionally, bone regeneration in the ADM/ASCs/LLLT group was obvious at 28 days, but in the ADM/ASCs group at 56 days. Bone mineral density and bone tissue volume in the ADM/ASCs/LLLT group significantly increased after 7 days, but in the ADM/ASCs group after 14 days. Histological analysis revealed that the defects were repaired in the ADM/ASCs and the ADM/ASCs/LLLT group, while the defects in the ADM and the ADM/LLLT groups exhibited few bone islands at 28 and 56 days. The successful seeding of ASCs onto ADM was confirmed, and LLLT enhanced the proliferation and the survival of ASCs at 14 days. Our results indicate that ASC-seeded grafts promote bone regeneration, and the application of LLLT on ASC-seeded ADM results in rapid bone formation. The implantation of an ASC-seeded ADM combined with LLLT may be used effectively for bone regeneration.

  19. Second-harmonic generation microscopy for assessment of mesenchymal stem cell-seeded acellular dermal matrix in wound-healing.

    PubMed

    Wang, Qiannan; Jin, Ying; Deng, Xiaoyuan; Liu, Hanping; Pang, Hongwen; Shi, Panpan; Zhan, Zhigang

    2015-01-01

    Direct intra-skin injection of mesenchymal stem cells (MSCs) and the use of biomaterial scaffolds for grafts are both promising approaches of skin wound repair, however they still cannot generate skin that completely resembles the natural skin structures. In this study, we combined these two approaches by using acellular dermal matrix (ADM) recellularized with MSCs to repair cutaneous wounds in a murine model and two-photon fluorescence (TPF) microscopy and second-harmonic generation (SHG) microscopy to assess the effects of this therapy on wound healing. Bone marrow-derived mesenchymal stem cells (BM-MSCs) were tagged with GFP and seeded into ADM (ADM-MSC) via MSC and ADM co-culture. ADM-MSC, ADM or saline was applied to murine excisional skin wounds and wound-healing was evaluated by histological examination on days 7, 14, 21 and TFP microscopy on days 1, 3, 5 and 21 post-treatment. ADM-MSC promoted healing significantly more than treatment with ADM or saline alone, as it led to substantial neovascularization and complete skin appendage regeneration. Furthermore, the SHG microscopic imaging technique proved to be a useful tool for monitoring changes in the collagen network at the wound site during the healing process and assessing the effects of different therapies.

  20. Production of an acellular matrix from amniotic membrane for the synthesis of a human skin equivalent.

    PubMed

    Sanluis-Verdes, Anahí; Yebra-Pimentel Vilar, Maria Teresa; García-Barreiro, Juan Javier; García-Camba, Marta; Ibáñez, Jacinto Sánchez; Doménech, Nieves; Rendal-Vázquez, Maria Esther

    2015-09-01

    Human amniotic membrane (HAM) has useful properties as a dermal matrix substitute. The objective of our work was to obtain, using different enzymatic or chemical treatments to eliminate cells, a scaffold of acellular HAM for later use as a support for the development of a skin equivalent. The HAM was separated from the chorion, incubated and cryopreserved. The membrane underwent different enzymatic and chemical treatments to eliminate the cells. Fibroblasts and keratinocytes were separately obtained from skin biopsies of patients following a sequential double digestion with first collagenase and then trypsin-EDTA (T/E). A skin equivalent was then constructed by seeding keratinocytes on the epithelial side and fibroblasts on the chorionic side of the decellularizated HAM. Histological, immunohistochemical, inmunofluorescent and molecular biology studies were performed. Treatment with 1% T/E at 37 °C for 30 min totally removed epithelial and mesenchymal cells. The HAM thus treated proved to be a good matrix to support adherence of cells and allowed the achievement of an integral and intact scaffold for development of a skin equivalent, which could be useful as a skin substitute for clinical use.

  1. Tissue performance of bladder following stretched electrospun silk fibroin matrix and bladder acellular matrix implantation in a rabbit model.

    PubMed

    Huang, Jian-Wen; Xu, Yue-Min; Li, Zhao-Bo; Murphy, Sean V; Zhao, Weixin; Liu, Qiang-Qiang; Zhu, Wei-Dong; Fu, Qiang; Zhang, Yao-Peng; Song, Lu-Jie

    2016-01-01

    The goal of this study was to investigate the tissue performance of bladder following stretched electrospun silk fibroin matrix (SESFM) implantation compared with bladder acellular matrix (BAM). We compared SESFM with BAM based on porosity and pore size. Scaffolds were separately transplanted into opposite walls of the bladder of 30 rabbits after stripping the bladder mucosa and smooth muscle (1.5 × 2.0 cm(2)). Gross anatomical observation, histological analysis and muscle contractility studies were performed at 2, 4, and 8 weeks post-op. SESFM has higher porosity and larger pore size compared with BAM (p < 0.05). At 2 weeks, the presence of vesical calculus was evident in 7/10 rabbits. Histological analysis showed that SESFM and BAM promoted similar degree of urothelium regeneration (p > 0.05). However, SESFM promoted a higher degree of smooth muscle and vessel regeneration compared to BAM (p < 0.05). In addition, muscle strips supported by SESFM displayed higher contractile responses to carbachol, KCl, and phenylephrine compared with BAM. At 8 weeks, both matrices elicited similar mild acute and chronic inflammatory reactions. Our results demonstrated that SESFM has greater ability to promote bladder tissue regeneration with structural and functional properties compared to BAM, and with similar biocompatibility. PMID:26148477

  2. Preparation and characterization of an advanced collagen aggregate from porcine acellular dermal matrix.

    PubMed

    Liu, Xinhua; Dan, Nianhua; Dan, Weihua

    2016-07-01

    The objective of this study was to extract and characterize an advanced collagen aggregate (Ag-col) from porcine acellular dermal matrix (pADM). Based on histological examination, scanning electron microscopy (SEM) and atomic force microscope (AFM), Ag-col was composed of the D-periodic cross-striated collagen fibrils and thick collagen fiber bundles with uneven diameters and non-orientated arrangement. Fourier transform infrared (FTIR) spectra of pADM, Ag-col and Col were similar and revealed the presence of the triple helix. Circular dichroism (CD) analysis exhibited a slightly higher content of α-helix but inappreciably less amount of random coil structure in Ag-col compared to Col. Moreover, imino acid contents of pADM, Ag-col and Col were 222.43, 218.30 and 190.01 residues/1000 residues, respectively. From zeta potential analysis, a net charge of zero was found at pH 6.45 and 6.11 for Ag-col and Col, respectively. Differential scanning calorimetry (DSC) study suggested that the Td of Ag-col was 20°C higher than that of Col as expected, and dynamic mechanical analysis (DMA) indicated that Ag-col possessed a higher storage modulus but similar loss factor compared to Col. Therefore, the collagen aggregate from pADM could serve as a better alternative source of collagens for further applications in food and biological industries. PMID:27039117

  3. Acellular dermal matrix slings in tissue expander breast reconstruction: are there substantial benefits?

    PubMed

    Collis, George N; TerKonda, Sarvam P; Waldorf, James C; Perdikis, Galen

    2012-05-01

    Acellular dermal matrix (ADM) slings in breast reconstruction are increasingly used but are not yet validated. This study compares immediate, expander-based breast reconstruction with and without the use of inferolateral ADM slings. There were 63 patients (106 breasts) in the ADM group and 42 patients (68 breasts) in the control group. Initial intraoperative fill volumes were significantly greater in the ADM group, median 69% full (250 mL) versus 50% full (180 mL; P < 0.001). However, the number of days to complete expansion between the 2 groups was similar. One less office visit was required to complete the fills in the ADM group (P < 0.01). Drains were removed 3 days later in the ADM group (P < 0.01). Overall complication rate was greater in the ADM group (18.9% vs. 7.4%, P < 0.05), with a slightly higher percentage of expanders requiring removal due to infection in the ADM group (5.7% vs. 4.4%, P = NS). This study suggests inferolateral ADM slings in expander-based breast reconstruction allow for significantly increased initial fill volumes and may offer an aesthetic advantage; however, its use is costly and increases complications.

  4. Glottic Regeneration with Tissue Engineering Technique Using Acellular Extracellular Matrix Scaffold in Canine Model

    PubMed Central

    Kitamura, Morimasa; Hirano, Shigeru; Kanemaru, Shin-ichi; Kitani, Yoshiharu; Ohno, Satoshi; Kojima, Tsuyoshi; Nakamura, Tatsuo; Ito, Juichi; Rosen, Clark A.; Gilbert, Thomas W.

    2014-01-01

    Acellular extracellular matrix scaffold derived from porcine urinary bladder (UBM) is decellularized material that has shown success for constructive remodeling of various tissues and organs. The regenerative effects of UBM were reported for the tympanic membrane, esophagus, trachea, larynx, pleura, and pericardium in animal studies with promising results. The aim of this study was to investigate regenerative effects of UBM to regenerate hemilarynx using a canine model. A left partial hemilaryngectomy was performed, and the surgical defects were reconstructed by insertion of UBM scaffold. Although local infection was observed in one dog in a week after implantation of the scaffold, all dogs showed good re-epithelialization with minimum complication in one month. The effect of regeneration of the larynx was evaluated 6 months after the operation. The excised larynx experiments were performed to measure phonation threshold pressure (PTP), normalized mucosal wave amplitude (NMWA), and normalized glottal gap (NGG). The results of the measurements showed that PTP was normal or near normal in 2 cases, NMWA was within normal range in 3 cases, although there were individual variations. Histologic examination was completed to evaluate structural changes of the scaffold with appearance of new cartilaginous structure. However the regenerated vocal fold mucosa is mostly scarred. The UBM scaffold has shown to be biocompatible, biodegradable, and useful for tissue regeneration of the hemilarynx with possible restoration of the vocal fold function. The vocal fold mucosa was scarred, which is the next challenge to improve. PMID:24403099

  5. Xenogeneic acellular dermal matrix in combination with pectoralis major myocutaneous flap reconstructs hypopharynx and cervical esophagus.

    PubMed

    Yin, Danhui; Tang, Qinglai; Wang, Shuang; Li, Shisheng; He, Xiangbo; Liu, Jiajia; Liu, Bingbing; Yang, Mi; Yang, Xinming

    2015-11-01

    The aim of this study was to explore xenogeneic acellular dermal matrix (ADM) in combination with pectoralis major myocutaneous flap in hypopharynx and cervical esophagus reconstruction. A total of five patients were treated with this surgical method to reconstruct hypopharynx and cervical esophagus in Second Xiangya Hospital between January 2012 and April 2013. Four of them had hypopharyngeal carcinoma with laryngeal and cervical esophageal invasion, while the fifth patient with hypopharyngeal cancer had developed scars and atresia after postoperative radiotherapy. The defect length after hypopharyngeal and cervical esophageal resection was 6-8 cm, and was repaired by a combination of ADM and pectoralis major myocutaneous flap by our team. Interestingly, the four patients had primary healing and regained their eating function about 2-3 weeks after surgery, the fifth individual suffered from pharyngeal fistula, but recovered after dressing change about 2 months. Postoperative esophageal barium meals revealed that the pharynx and esophagus were unobstructed in all five patients. Xenogeneic ADM in combination with pectoralis major myocutaneous flap for hypopharynx and cervical esophagus reconstruction is a simple, safe and effective method with fewer complications. Nevertheless, according to the defect length of the cervical esophagus, the patients need to strictly follow the medical advice.

  6. Possible role of dentin matrix in region-specific deposition of cellular and acellular extrinsic fibre cementum.

    PubMed

    Takano, Yoshiro; Sakai, Hideo; Watanabe, Eiko; Ideguchi-Ohma, Noriko; Jayawardena, Chantha K; Arai, Kazumi; Asawa, Yukiyo; Nakano, Yukiko; Shuda, Yoko; Sakamoto, Yujiro; Terashima, Tatsuo

    2003-01-01

    The mechanism whereby a region-specific deposition of the two types of cementum (cellular cementum and acellular extrinsic fibre cementum) is regulated on the growing root surface was tested using bisphosphonate-affected teeth of young rats and guinea pigs. The animals were injected subcutaneously with 8 or 10 mg P x kg body weight(-1) x day(-1) of 1-hydroxyethylidene-1,1-bisphosphonate (HEBP) for 1 or 2 weeks. In rat molars, HEBP prevented mineralization of newly formed root dentin matrix and totally inhibited de novo deposition of acellular extrinsic fibre cementum. Instead, thick cellular cementum was induced on the non-mineralized root dentin surface, irrespective of the position of the root. In both animals, cellular cementum was also induced on the non-mineralized surface of root analogue dentin in HEBP-affected incisors, where only acellular extrinsic fibre cementum is deposited under normal conditions. In normal rat molars, dentin sialoprotein (DSP) was concentrated along the dentin-cellular cementum border, but not that of dentin and acellular extrinsic fibre cementum. In HEBP-affected rat incisors, DSP was shown to penetrate through the non-mineralized dentin into the surrounding tissues, but not through the mineralized portions. These data suggest that, at the site of cellular cementum formation, putative inducing factors for cellular cementum might diffuse into the periodontal space through the newly deposited mantle dentin matrix before it is mineralized. At earlier stages of root formation, mantle dentin might mineralize more promptly not to allow such diffusion. The timing of mineralization of mantle dentin matrix might be the key determinant of the types of the cementum deposited on the growing root surface. PMID:14756246

  7. Plastic Surgery and Acellular Dermal Matrix: Highlighting Trends from 1999 to 2013.

    PubMed

    Daar, David A; Gandy, Jessica R; Clark, Emily G; Mowlds, Donald S; Paydar, Keyianoosh Z; Wirth, Garrett A

    2016-05-01

    The last decade has ushered in a rapidly expanding global discussion regarding acellular dermal matrix (ADM) applications, economic analyses, technical considerations, benefits, and risks, with recent emphasis on ADM use in breast surgery. This study aims to evaluate global trends in ADM research using bibliometric analysis. The top nine Plastic Surgery journals were determined by impact factor (IF). Each issue of the nine journals between 1999 and 2013 was accessed to compile a database of articles discussing ADM. Publications were further classified by IF, authors' geographic location, study design, and level of evidence (LOE, I-V). Productivity index and productivity share were calculated for each region. In total, 256 ADM articles were accessed. The annual global publication volume increased significantly by 4.2 (0.87) articles per year (p<0.001), with a mean productivity index of 36.3 (59.0). The mean impact factor of the nine journals increased significantly from 0.61 (0.11) to 2.47 (0.99) from 1993 to 2013 (p<0.001). Despite this increase in the global ADM literature, the majority of research was of weaker LOE (level I: 2.29% and level II: 9.17%). USA contributed the most research (87%), followed by Asia (4.76%) and Western Europe (4.71%). USA contributed the greatest volume of research. Regarding clinical application of ADM, the majority of publications focused on ADM use in breast surgery, specifically breast reconstruction (154 articles, 60.2%). The majority of research was of lower LOE; thus, efforts should be made to strengthen the body of literature, particularly with regard to cost analysis.

  8. Plastic Surgery and Acellular Dermal Matrix: Highlighting Trends from 1999 to 2013.

    PubMed

    Daar, David A; Gandy, Jessica R; Clark, Emily G; Mowlds, Donald S; Paydar, Keyianoosh Z; Wirth, Garrett A

    2016-05-01

    The last decade has ushered in a rapidly expanding global discussion regarding acellular dermal matrix (ADM) applications, economic analyses, technical considerations, benefits, and risks, with recent emphasis on ADM use in breast surgery. This study aims to evaluate global trends in ADM research using bibliometric analysis. The top nine Plastic Surgery journals were determined by impact factor (IF). Each issue of the nine journals between 1999 and 2013 was accessed to compile a database of articles discussing ADM. Publications were further classified by IF, authors' geographic location, study design, and level of evidence (LOE, I-V). Productivity index and productivity share were calculated for each region. In total, 256 ADM articles were accessed. The annual global publication volume increased significantly by 4.2 (0.87) articles per year (p<0.001), with a mean productivity index of 36.3 (59.0). The mean impact factor of the nine journals increased significantly from 0.61 (0.11) to 2.47 (0.99) from 1993 to 2013 (p<0.001). Despite this increase in the global ADM literature, the majority of research was of weaker LOE (level I: 2.29% and level II: 9.17%). USA contributed the most research (87%), followed by Asia (4.76%) and Western Europe (4.71%). USA contributed the greatest volume of research. Regarding clinical application of ADM, the majority of publications focused on ADM use in breast surgery, specifically breast reconstruction (154 articles, 60.2%). The majority of research was of lower LOE; thus, efforts should be made to strengthen the body of literature, particularly with regard to cost analysis. PMID:27579264

  9. Randomized controlled trial of minimally invasive surgery using acellular dermal matrix for complex anorectal fistula

    PubMed Central

    A ba-bai-ke-re, Ma-Mu-Ti-Jiang; Wen, Hao; Huang, Hong-Guo; Chu, Hui; Lu, Ming; Chang, Zhong-Sheng; Ai, Er-Ha-Ti; Fan, Kai

    2010-01-01

    AIM: To compare the efficacy and safety of acellular dermal matrix (ADM) bioprosthetic material and endorectal advancement flap (ERAF) in treatment of complex anorectal fistula. METHODS: Ninety consecutive patients with complex anorectal fistulae admitted to Anorectal Surgical Department of First Affiliated Hospital, Xinjiang Medical University from March 2008 to July 2009, were enrolled in this study. Complex anorectal fistula was diagnosed following its clinical, radiographic, or endoscopic diagnostic criteria. Under spinal anesthesia, patients underwent identification and irrigation of the fistula tracts using hydrogen peroxide. ADM was securely sutured at the secondary opening to the primary opening using absorbable suture. Outcomes of ADM and ERAF closure were compared in terms of success rate, fecal incontinence rate, anorectal deformity rate, postoperative pain time, closure time and life quality score. Success was defined as closure of all external openings, absence of drainage without further intervention, and absence of abscess formation. Follow-up examination was performed 2 d, 2, 4, 6, 12 wk, and 5 mo after surgery, respectively. RESULTS: No patient was lost to follow-up. The overall success rate was 82.22% (37/45) 5.7 mo after surgery. ADM dislodgement occured in 5 patients (11.11%), abscess formation was found in 1 patient, and fistula recurred in 2 patients. Of the 13 patients with recurrent fistula using ERAF, 5 (11.11%) received surgical drainage because of abscess formation. The success rate, postoperative pain time and closure time of ADM were significantly higher than those of ERAF (P < 0.05). However, no difference was observed in fecal incontinence rate and anorectal deformity rate after treatment with ADM and ERAF. CONCLUSION: Closure of fistula tract opening with ADM is an effective procedure for complex anorectal fistula. ADM should be considered a first line treatment for patients with complex anorectal fistula. PMID:20614483

  10. Plastic Surgery and Acellular Dermal Matrix: Highlighting Trends from 1999 to 2013

    PubMed Central

    Daar, David A; Gandy, Jessica R; Clark, Emily G; Mowlds, Donald S; Paydar, Keyianoosh Z; Wirth, Garrett A

    2016-01-01

    The last decade has ushered in a rapidly expanding global discussion regarding acellular dermal matrix (ADM) applications, economic analyses, technical considerations, benefits, and risks, with recent emphasis on ADM use in breast surgery. This study aims to evaluate global trends in ADM research using bibliometric analysis. The top nine Plastic Surgery journals were determined by impact factor (IF). Each issue of the nine journals between 1999 and 2013 was accessed to compile a database of articles discussing ADM. Publications were further classified by IF, authors’ geographic location, study design, and level of evidence (LOE, I-V). Productivity index and productivity share were calculated for each region. In total, 256 ADM articles were accessed. The annual global publication volume increased significantly by 4.2 (0.87) articles per year (p<0.001), with a mean productivity index of 36.3 (59.0). The mean impact factor of the nine journals increased significantly from 0.61 (0.11) to 2.47 (0.99) from 1993 to 2013 (p<0.001). Despite this increase in the global ADM literature, the majority of research was of weaker LOE (level I: 2.29% and level II: 9.17%). USA contributed the most research (87%), followed by Asia (4.76%) and Western Europe (4.71%). USA contributed the greatest volume of research. Regarding clinical application of ADM, the majority of publications focused on ADM use in breast surgery, specifically breast reconstruction (154 articles, 60.2%). The majority of research was of lower LOE; thus, efforts should be made to strengthen the body of literature, particularly with regard to cost analysis. PMID:27579264

  11. Acellular Dermal Matrix as a Core Strut for Projection in Nipple Reconstruction: Approaches for Three Different Methods of Breast Reconstruction

    PubMed Central

    Park, Gui-Yong; Cho, Hee-Eun; Lee, Byung-Il; Park, Seung-Ha

    2016-01-01

    Background The objective of this paper was to describe a novel technique for improving the maintenance of nipple projection in primary nipple reconstruction by using acellular dermal matrix as a strut in one of three different configurations, according to the method of prior breast reconstruction. The struts were designed to best fill the different types of dead spaces in nipple reconstruction depending on the breast reconstruction method. Methods A total of 50 primary nipple reconstructions were performed between May 2012 and May 2015. The prior breast reconstruction methods were latissimus dorsi (LD) flap (28 cases), transverse rectus abdominis myocutaneous (TRAM) flap (10 cases), or tissue expander/implant (12 cases). The nipple reconstruction technique involved the use of local flaps, including the C-V flap or star flap. A 1×2-cm acellular dermal matrix was placed into the core with O-, I-, and L-shaped struts for prior LD, TRAM, and expander/implant methods, respectively. The projection of the reconstructed nipple was measured at the time of surgery and at 3, 6, and 9 months postoperatively. Results The nine-month average maintenance of nipple projection was 73.0%±9.67% for the LD flap group using an O-strut, 72.0%±11.53% for the TRAM flap group using an I-strut, and 69.0%±10.82% for the tissue expander/implant group using an L-strut. There were no cases of infection, wound dehiscence, or flap necrosis. Conclusions The application of an acellular dermal matrix with a different kind of strut for each of 3 breast reconstruction methods is an effective addition to current techniques for improving the maintenance of long-term projection in primary nipple reconstruction. PMID:27689049

  12. Acellular Dermal Matrix as a Core Strut for Projection in Nipple Reconstruction: Approaches for Three Different Methods of Breast Reconstruction

    PubMed Central

    Park, Gui-Yong; Cho, Hee-Eun; Lee, Byung-Il; Park, Seung-Ha

    2016-01-01

    Background The objective of this paper was to describe a novel technique for improving the maintenance of nipple projection in primary nipple reconstruction by using acellular dermal matrix as a strut in one of three different configurations, according to the method of prior breast reconstruction. The struts were designed to best fill the different types of dead spaces in nipple reconstruction depending on the breast reconstruction method. Methods A total of 50 primary nipple reconstructions were performed between May 2012 and May 2015. The prior breast reconstruction methods were latissimus dorsi (LD) flap (28 cases), transverse rectus abdominis myocutaneous (TRAM) flap (10 cases), or tissue expander/implant (12 cases). The nipple reconstruction technique involved the use of local flaps, including the C-V flap or star flap. A 1×2-cm acellular dermal matrix was placed into the core with O-, I-, and L-shaped struts for prior LD, TRAM, and expander/implant methods, respectively. The projection of the reconstructed nipple was measured at the time of surgery and at 3, 6, and 9 months postoperatively. Results The nine-month average maintenance of nipple projection was 73.0%±9.67% for the LD flap group using an O-strut, 72.0%±11.53% for the TRAM flap group using an I-strut, and 69.0%±10.82% for the tissue expander/implant group using an L-strut. There were no cases of infection, wound dehiscence, or flap necrosis. Conclusions The application of an acellular dermal matrix with a different kind of strut for each of 3 breast reconstruction methods is an effective addition to current techniques for improving the maintenance of long-term projection in primary nipple reconstruction.

  13. Acellular dermal matrix and negative pressure wound therapy: a tissue-engineered alternative to free tissue transfer in the compromised host.

    PubMed

    Menn, Zachary K; Lee, Edward; Klebuc, Michael J

    2012-02-01

    Free tissue transfer has revolutionized lower extremity reconstruction; however, its use in elderly patients with multiple medical problems can be associated with elevated rate s of perioperative morbidity and mortality. This study evaluates the use of acellular dermal matrix (ADM) in conjunction with negative pressure wound therapy (NPWT) and delayed skin graft application as an alternative to free tissue transfer in this compromised population. Bilayer, ADM (Integra, Plainsboro, NJ) was used in conjunction with NPWT (Wound V.A.C, Kinetic Concepts Inc., San Antonio, TX) to achieve vascularized coverage of complex lower extremity wounds with denuded tendon and bone in elderly, medically compromised patients. Following incorporation, the matrix was covered with split-thickness skin graft. Four patients (age range, 50 to 76 years) with multiple medical comorbidities were treated with the above protocol. The average time to complete vascularization of the matrix was 29 days. Definitive closure with split-thickness skin graft was achieved in three patients and one wound healed by secondary intention. No medical or surgical complications were encountered and stable soft tissue coverage was achieved in all patients. This early experience suggests that dermal substitute and NPWT with delayed skin graft application can provide a reasonable tissue-engineered alternative to free tissue transfer in the medically compromised individual.

  14. Acellular allogeneic nerve grafting combined with bone marrow mesenchymal stem cell transplantation for the repair of long-segment sciatic nerve defects: biomechanics and validation of mathematical models

    PubMed Central

    Li, Ya-jun; Zhao, Bao-lin; Lv, Hao-ze; Qin, Zhi-gang; Luo, Min

    2016-01-01

    We hypothesized that a chemically extracted acellular allogeneic nerve graft used in combination with bone marrow mesenchymal stem cell transplantation would be an effective treatment for long-segment sciatic nerve defects. To test this, we established rabbit models of 30 mm sciatic nerve defects, and treated them using either an autograft or a chemically decellularized allogeneic nerve graft with or without simultaneous transplantation of bone marrow mesenchymal stem cells. We compared the tensile properties, electrophysiological function and morphology of the damaged nerve in each group. Sciatic nerves repaired by the allogeneic nerve graft combined with stem cell transplantation showed better recovery than those repaired by the acellular allogeneic nerve graft alone, and produced similar results to those observed with the autograft. These findings confirm that a chemically extracted acellular allogeneic nerve graft combined with transplantation of bone marrow mesenchymal stem cells is an effective method of repairing long-segment sciatic nerve defects. PMID:27651781

  15. Acellular allogeneic nerve grafting combined with bone marrow mesenchymal stem cell transplantation for the repair of long-segment sciatic nerve defects: biomechanics and validation of mathematical models

    PubMed Central

    Li, Ya-jun; Zhao, Bao-lin; Lv, Hao-ze; Qin, Zhi-gang; Luo, Min

    2016-01-01

    We hypothesized that a chemically extracted acellular allogeneic nerve graft used in combination with bone marrow mesenchymal stem cell transplantation would be an effective treatment for long-segment sciatic nerve defects. To test this, we established rabbit models of 30 mm sciatic nerve defects, and treated them using either an autograft or a chemically decellularized allogeneic nerve graft with or without simultaneous transplantation of bone marrow mesenchymal stem cells. We compared the tensile properties, electrophysiological function and morphology of the damaged nerve in each group. Sciatic nerves repaired by the allogeneic nerve graft combined with stem cell transplantation showed better recovery than those repaired by the acellular allogeneic nerve graft alone, and produced similar results to those observed with the autograft. These findings confirm that a chemically extracted acellular allogeneic nerve graft combined with transplantation of bone marrow mesenchymal stem cells is an effective method of repairing long-segment sciatic nerve defects.

  16. Surgical Outcomes of Deep Superior Sulcus Augmentation Using Acellular Human Dermal Matrix in Anophthalmic or Phthisis Socket.

    PubMed

    Cho, Won-Kyung; Jung, Su-Kyung; Paik, Ji-Sun; Yang, Suk-Woo

    2016-07-01

    Patients with anophthalmic or phthisis socket suffer from cosmetic problems. To resolve those problems, the authors present the surgical outcomes of deep superior sulcus (DSS) augmentation using acellular dermal matrix in patients with anophthalmic or phthisis socket. The authors retrospectively reviewed anophthalmic or phthisis patients who underwent surgery for DSS augmentation using acellular dermal matrix. To evaluate surgical outcomes, the authors focused on 3 aspects: the possibility of wearing contact prosthesis, the degree of correction of the DSS, and any surgical complications. The degree of correction of DSS was classified as excellent: restoration of superior sulcus enough to remove sunken sulcus shadow; fair: gain of correction effect but sunken shadow remained; or fail: no effect of correction at all. Ten eyes of 10 patients were included. There was a mean 21.3 ± 37.1-month period from evisceration or enucleation to the operation for DSS augmentation. All patients could wear contact prosthesis after the operation (100%). The degree of correction was excellent in 8 patients (80%) and fair in 2. Three of 10 (30%) showed complications: eyelid entropion, upper eyelid multiple creases, and spontaneous wound dehiscence followed by inflammation after stitch removal. Uneven skin surface and paresthesia in the forehead area of the affected eye may be observed after surgery. The overall surgical outcomes were favorable, showing an excellent degree of correction of DSS and low surgical complication rates. This procedure is effective for patients who have DSS in the absence or atrophy of the eyeball.

  17. Sustained release of VEGF from PLGA nanoparticles embedded thermo-sensitive hydrogel in full-thickness porcine bladder acellular matrix

    PubMed Central

    2011-01-01

    We fabricated a novel vascular endothelial growth factor (VEGF)-loaded poly(lactic-co-glycolic acid) (PLGA)-nanoparticles (NPs)-embedded thermo-sensitive hydrogel in porcine bladder acellular matrix allograft (BAMA) system, which is designed for achieving a sustained release of VEGF protein, and embedding the protein carrier into the BAMA. We identified and optimized various formulations and process parameters to get the preferred particle size, entrapment, and polydispersibility of the VEGF-NPs, and incorporated the VEGF-NPs into the (poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) (Pluronic®) F127 to achieve the preferred VEGF-NPs thermo-sensitive gel system. Then the thermal behavior of the system was proven by in vitro and in vivo study, and the kinetic-sustained release profile of the system embedded in porcine bladder acellular matrix was investigated. Results indicated that the bioactivity of the encapsulated VEGF released from the NPs was reserved, and the VEGF-NPs thermo-sensitive gel system can achieve sol-gel transmission successfully at appropriate temperature. Furthermore, the system can create a satisfactory tissue-compatible environment and an effective VEGF-sustained release approach. In conclusion, a novel VEGF-loaded PLGA NPs-embedded thermo-sensitive hydrogel in porcine BAMA system is successfully prepared, to provide a promising way for deficient bladder reconstruction therapy. PMID:21711840

  18. Surgical Outcomes of Deep Superior Sulcus Augmentation Using Acellular Human Dermal Matrix in Anophthalmic or Phthisis Socket.

    PubMed

    Cho, Won-Kyung; Jung, Su-Kyung; Paik, Ji-Sun; Yang, Suk-Woo

    2016-07-01

    Patients with anophthalmic or phthisis socket suffer from cosmetic problems. To resolve those problems, the authors present the surgical outcomes of deep superior sulcus (DSS) augmentation using acellular dermal matrix in patients with anophthalmic or phthisis socket. The authors retrospectively reviewed anophthalmic or phthisis patients who underwent surgery for DSS augmentation using acellular dermal matrix. To evaluate surgical outcomes, the authors focused on 3 aspects: the possibility of wearing contact prosthesis, the degree of correction of the DSS, and any surgical complications. The degree of correction of DSS was classified as excellent: restoration of superior sulcus enough to remove sunken sulcus shadow; fair: gain of correction effect but sunken shadow remained; or fail: no effect of correction at all. Ten eyes of 10 patients were included. There was a mean 21.3 ± 37.1-month period from evisceration or enucleation to the operation for DSS augmentation. All patients could wear contact prosthesis after the operation (100%). The degree of correction was excellent in 8 patients (80%) and fair in 2. Three of 10 (30%) showed complications: eyelid entropion, upper eyelid multiple creases, and spontaneous wound dehiscence followed by inflammation after stitch removal. Uneven skin surface and paresthesia in the forehead area of the affected eye may be observed after surgery. The overall surgical outcomes were favorable, showing an excellent degree of correction of DSS and low surgical complication rates. This procedure is effective for patients who have DSS in the absence or atrophy of the eyeball. PMID:27258711

  19. Open flap debridement in combination with acellular dermal matrix allograft for the prevention of postsurgical gingival recession: a case series.

    PubMed

    Chavan, Ramesh Sundersing; Bhongade, Manohar Laxman; Tiwari, Ishan Ramakant; Jaiswal, Priyanka

    2013-01-01

    Open flap debridement with flap repositioning may result in significant gingival recession. Patients with chronic periodontitis were treated with open flap debridement followed by placement of an acellular dermal matrix allograft (ADMA) underneath the flap to minimize the occurrence of postsurgical gingival recession. Ten patients (total, 60 teeth) with periodontal pockets in the anterior dentition underwent open flap debridement combined with ADMA. Probing pocket depth, relative attachment level, and relative gingival margin level were recorded at baseline and 6 months postsurgery. The mean probing pocket depth at baseline and 6 months was 4.4 and 1.7 mm, respectively (P < .05); the mean relative attachment level at baseline and 6 months was 12.9 and 10.7 mm, respectively (P < .05); and the mean relative gingival margin level at baseline and 6 months was 8.4 and 9.0 mm, respectively. ADMA underneath the flap when combined with open flap debridement effectively minimizes postsurgical gingival recession.

  20. Application of Bladder Acellular Matrix in Urinary Bladder Regeneration: The State of the Art and Future Directions

    PubMed Central

    Pokrywczynska, Marta; Drewa, Gerard; Drewa, Tomasz

    2015-01-01

    Construction of the urinary bladder de novo using tissue engineering technologies is the “holy grail” of reconstructive urology. The search for the ideal biomaterial for urinary bladder reconstruction has been ongoing for decades. One of the most promising biomaterials for this purpose seems to be bladder acellular matrix (BAM). In this review we determine the most important factors, which may affect biological and physical properties of BAM and its regeneration potential in tissue engineered urinary bladder. We also point out the directions in modification of BAM, which include incorporation of exogenous growth factors into the BAM structure. Finally, we discuss the results of the urinary bladder regeneration with cell seeded BAM. PMID:25793199

  1. Use of Double Layer of Acellular Dermal Matrix and Modified Tunnel Technique to Treat Multiple Adjacent Gingival Recession Defects.

    PubMed

    Mahn, Douglas H

    2016-09-01

    The goal of connective tissue grafting is to cover exposed root surfaces with gingival tissues that are stable and have a natural appearance. The use of an acellular dermal matrix (ADM) has been shown to be a successful alternative to the palatal connective tissue graft. Use of a double layer of an ADM has been shown to have stable results for 1 year. Tunnel grafting techniques can yield root coverage with a natural appearing soft-tissue architecture. The purpose of this case report is to demonstrate the use of a modified tunnel technique and a double layer of ADM in the treatment of multiple adjacent gingival recession defects. Treated teeth were found to have root coverage and natural soft-tissue contours that were stable at 20 months. PMID:27606567

  2. Acellular porcine corneal matrix as a carrier scaffold for cultivating human corneal epithelial cells and fibroblasts in vitro

    PubMed Central

    Zhang, Ju; Zhang, Can-Wei; Du, Li-Qun; Wu, Xin-Yi

    2016-01-01

    AIM To investigate the feasibility of corneal anterior lamellar reconstruction with human corneal epithelial cells and fibroblasts, and an acellular porcine cornea matrix (APCM) in vitro. METHODS The scaffold was prepared from fresh porcine corneas which were treated with 0.5% sodium dodecyl sulfate (SDS) solution and the complete removal of corneal cells was confirmed by hematoxylin-eosin (HE) staining and 4′, 6-diamidino-2-phenylindole (DAPI) staining. Human corneal fibroblasts and epithelial cells were cultured with leaching liquid extracted from APCM, and then cell proliferative ability was evaluated by MTT assay. To construct a human corneal anterior lamellar replacement, corneal fibroblasts were injected into the APCM and cultured for 3d, followed by culturing corneal epithelial cells on the stroma construction surface for another 10d. The corneal replacement was analyzed by HE staining, and immunofluorescence staining. RESULTS Histological examination indicated that there were no cells in the APCM by HE staining, and DAPI staining did not detect any residual DNA. The leaching liquid from APCM had little influence on the proliferation ability of human corneal fibroblasts and epithelial cells. At 10d, a continuous 3 to 5 layers of human corneal epithelial cells covering the surface of the APCM was observed, and the injected corneal fibroblasts distributed within the scaffold. The phenotype of the construction was similar to normal human corneas, with high expression of cytokeratin 12 in the epithelial cell layer and high expression of vimentin in the stroma. CONCLUSION Corneal anterior lamellar replacement can be reconstructed in vitro by cultivating human corneal epithelial cells and fibroblasts with an acellular porcine cornea matrix. This laid the foundation for the further transplantation in vivo. PMID:26949602

  3. Acellular human glans extracellular matrix as a scaffold for tissue engineering: in vitro cell support and biocompatibility

    PubMed Central

    Egydio, Fernanda M.; Freitas, Luiz G.; Sayeg, Kleber; Laks, Marcus; Oliveira, Andréia S.; Almeida, Fernando G.

    2015-01-01

    ABSTRACT Objectives: Diseases of the genitourinary tract can lead to significant damage. Current reconstructive techniques are limited by tissue availability and compatibility. This study aims to assess if the decellularized human glans can be used as a biomaterial for penile reconstruction. Materials and Methods: Samples of the glans matrices were descellularized. We evaluate the presence of collagen type I and III, and elastic fibers. Biocompatibility assays were performed to assess the cytotoxic and non-cytotoxic interactions between the acellular matrix and 3T3 cells. The matrices were seeded with mesenchymal stem cells and were assessed for viability and integration of these cells. Biomechanical tests in native tissue, descellularized matrix and seeded matrix were performed to characterize their biomechanical properties. Results: The tissue architecture of the decellularized matrix of human glans was preserved as well as the maintenance of the biomechanical and biological properties. The analyzes of glans seeded with mesenchymal stem cells revealed the integration of these cells to the matrices, and its viability during two weeks “in vitro”. Conclusion: The decellularization process did not alter the biological and biomechanical characteristics of the human glans. When these matrices were seeded they were able to maintain the cells integrity and vitality. PMID:26689526

  4. Acellular human heart matrix: A critical step toward whole heart grafts.

    PubMed

    Sánchez, Pedro L; Fernández-Santos, M Eugenia; Costanza, Salvatore; Climent, Andreu M; Moscoso, Isabel; Gonzalez-Nicolas, M Angeles; Sanz-Ruiz, Ricardo; Rodríguez, Hugo; Kren, Stefan M; Garrido, Gregorio; Escalante, Jose L; Bermejo, Javier; Elizaga, Jaime; Menarguez, Javier; Yotti, Raquel; Pérez del Villar, Candelas; Espinosa, M Angeles; Guillem, María S; Willerson, James T; Bernad, Antonio; Matesanz, Rafael; Taylor, Doris A; Fernández-Avilés, Francisco

    2015-08-01

    The best definitive treatment option for end-stage heart failure currently is transplantation, which is limited by donor availability and immunorejection. Generating an autologous bioartificial heart could overcome these limitations. Here, we have decellularized a human heart, preserving its 3-dimensional architecture and vascularity, and recellularized the decellularized extracellular matrix (dECM). We decellularized 39 human hearts with sodium-dodecyl-sulfate for 4-8 days. Cell removal and architectural integrity were determined anatomically, functionally, and histologically. To assess cytocompatibility, we cultured human cardiac-progenitor cells (hCPC), bone-marrow mesenchymal cells (hMSCs), human endothelial cells (HUVECs), and H9c1 and HL-1 cardiomyocytes in vitro on dECM ventricles up to 21 days. Cell survival, gene expression, organization and/or electrical coupling were analyzed and compared to conventional 2-dimensional cultures. Decellularization removed cells but preserved the 3-dimensional cardiac macro and microstructure and the native vascular network in a perfusable state. Cell survival was observed on dECM for 21 days. hCPCs and hMSCs expressed cardiocyte genes but did not adopt cardiocyte morphology or organization; HUVECs formed a lining of endocardium and vasculature; differentiated cardiomyocytes organized into nascent muscle bundles and displayed mature calcium dynamics and electrical coupling in recellularized dECM. In summary, decellularization of human hearts provides a biocompatible scaffold that retains 3-dimensional architecture and vascularity and that can be recellularized with parenchymal and vascular cells. dECM promotes cardiocyte gene expression in stem cells and organizes existing cardiomyocytes into nascent muscle showing electrical coupling. These findings represent a first step toward manufacturing human heart grafts or matrix components for treating cardiovascular disease.

  5. Galectin-1-induced skeletal muscle cell differentiation of mesenchymal stem cells seeded on an acellular dermal matrix improves injured anal sphincter.

    PubMed

    Ding, Zhao; Liu, Xiangui; Ren, Xianghai; Zhang, Qiulei; Zhang, Tingtao; Qian, Qun; Liu, Weicheng; Jiang, Congqing

    2016-05-01

    According to recent studies, mesenchymal stromal cells (MSCs) transplanted via local or tail vein injection can improve healing after anal sphincter injury (ASI) in animal models. However, the transplanted MSCs do not generate skeletal muscle that completely resembles the natural anal sphincter structure. In the present study, we investigated whether bone marrow (BM)-derived MSCs could be induced by Galectin-1 (Gal-1) to differentiate into skeletal muscle and whether the recellularization of an acellular dermal matrix (ADM) with skeletal muscle-differentiated MSCs represents a promising approach to restore ASI in a rat model. BM-MSCs subjected to adenovirus-mediated transfection with Gal-1-GFP (Ad-GFP-Gal-1) displayed increased Gal-1 and desmin expression and differentiated into skeletal muscle cells. MSCs transfected with Ad-GFP-Gal-1 (MSC-Gal-1) were seeded onto an ADM (ADM-MSC-Gal-1) via co-culture, and fusion was observed using a confocal laser scanning microscope. ADM-MSC-Gal-1, ADM-MSC, ADM-MSC-Ad, ADM, or a saline control was applied to a rat ASI model, and injury healing was evaluated via histological examination 6 weeks following treatment. ADM-MSC-Gal-1 treatment promoted significant healing after ASI and improved external anal sphincter contraction curves compared with the other treatments and also led to substantial skeletal muscle regeneration and neovascularization. Our results indicate that repair using ADMs and differentiated MSCs may improve muscle regeneration and restore ASI. PMID:27355329

  6. Effects of hydroxyapatite nanostructure on channel surface of porcine acellular dermal matrix scaffold on cell viability and osteogenic differentiation of human periodontal ligament stem cells.

    PubMed

    Ge, Shaohua; Zhao, Ning; Wang, Lu; Liu, Hong; Yang, Pishan

    2013-01-01

    A new nanostructured hydroxyapatite-coated porcine acellular dermal matrix (HAp-PADM) was fabricated by a biomimetic mineralization method. Human periodontal ligament stem cells were seeded on HAp-PADM and the effects of this scaffold on cell shape, cytoskeleton organization, cell viability, and osteogenic differentiation were examined. Periodontal ligament stem cells cultured on HAp-PADM exhibited different cell shape when compared with those on pure PADM. Moreover, HAp-PADM promoted cell viability and alkaline phosphatase activity significantly. Based on quantitative real-time polymerase chain reaction, the expression of bone-related markers runt-related transcription factor 2 (Runx2), osteopontin (OPN), and osteocalcin (OCN) upregulated in the HAp-PADM scaffold. The enhancement of osteogenic differentiation of periodontal ligament stem cells on the HAp-PADM scaffold was proposed based on the research results. The results of this study highlight the micro-nano, two-level, three-dimensional HAp-PADM composite as a promising scaffold for periodontal tissue engineering.

  7. Hepatic differentiation of human pluripotent stem cells on human liver progenitor HepaRG-derived acellular matrix.

    PubMed

    Kanninen, Liisa K; Porola, Pauliina; Niklander, Johanna; Malinen, Melina M; Corlu, Anne; Guguen-Guillouzo, Christiane; Urtti, Arto; Yliperttula, Marjo L; Lou, Yan-Ru

    2016-02-15

    Human hepatocytes are extensively needed in drug discovery and development. Stem cell-derived hepatocytes are expected to be an improved and continuous model of human liver to study drug candidates. Generation of endoderm-derived hepatocytes from human pluripotent stem cells (hPSCs), including human embryonic stem cells and induced pluripotent stem cells, is a complex, challenging process requiring specific signals from soluble factors and insoluble matrices at each developmental stage. In this study, we used human liver progenitor HepaRG-derived acellular matrix (ACM) as a hepatic progenitor-specific matrix to induce hepatic commitment of hPSC-derived definitive endoderm (DE) cells. The DE cells showed much better attachment to the HepaRG ACM than other matrices tested and then differentiated towards hepatic cells, which expressed hepatocyte-specific makers. We demonstrate that Matrigel overlay induced hepatocyte phenotype and inhibited biliary epithelial differentiation in two hPSC lines studied. In conclusion, our study demonstrates that the HepaRG ACM, a hepatic progenitor-specific matrix, plays an important role in the hepatic differentiation of hPSCs.

  8. Glycerolized Reticular Dermis as a New Human Acellular Dermal Matrix: An Exploratory Study.

    PubMed

    Ferrando, Pietro Maria; Balmativola, Davide; Cambieri, Irene; Scalzo, Maria Stella; Bergallo, Massimiliano; Annaratone, Laura; Casarin, Stefania; Fumagalli, Mara; Stella, Maurizio; Sapino, Anna; Castagnoli, Carlotta

    2016-01-01

    Human Acellular Dermal Matrices (HADM) are employed in various reconstructive surgery procedures as scaffolds for autologous tissue regeneration. The aim of this project was to develop a new type of HADM for clinical use, composed of glycerolized reticular dermis decellularized through incubation and tilting in Dulbecco's Modified Eagle's Medium (DMEM). This manufacturing method was compared with a decellularization procedure already described in the literature, based on the use of sodium hydroxide (NaOH), on samples from 28 donors. Cell viability was assessed using an MTT assay and microbiological monitoring was performed on all samples processed after each step. Two surgeons evaluated the biomechanical characteristics of grafts of increasing thickness. The effects of the different decellularization protocols were assessed by means of histological examination and immunohistochemistry, and residual DNA after decellularization was quantified using a real-time TaqMan MGB probe. Finally, we compared the results of DMEM based decellularization protocol on reticular dermis derived samples with the results of the same protocol applied on papillary dermis derived grafts. Our experimental results indicated that the use of glycerolized reticular dermis after 5 weeks of treatment with DMEM results in an HADM with good handling and biocompatibility properties. PMID:26918526

  9. Does Acellular Dermal Matrix Thickness Affect Complication Rate in Tissue Expander Based Breast Reconstruction?

    PubMed Central

    2016-01-01

    Background. While the benefits of using acellular dermal matrices (ADMs) in breast reconstruction are well described, their use has been associated with additional complications. The purpose of this study was to determine if ADM thickness affects complications in breast reconstruction. Methods. A retrospective chart review was performed including all tissue expander based breast reconstructions with AlloDerm (LifeCell, Branchburg, NJ) over 4 years. We evaluated preoperative characteristics and assessed postoperative complications including seroma, hematoma, infection, skin necrosis, and need for reintervention. We reviewed ADM thickness and time to Jackson-Pratt (JP) drain removal. Results. Fifty-five patients underwent 77 ADM-associated tissue expander based breast reconstructions, with average age of 48.1 years and average BMI of 25.9. Average ADM thickness was 1.21 mm. We found higher complication rates in the thick ADM group. Significant associations were found between smokers and skin necrosis (p < 0.0001) and seroma and prolonged JP drainage (p = 0.0004); radiated reconstructed breasts were more likely to suffer infections (p = 0.0085), and elevated BMI is a significant predictor for increased infection rate (p = 0.0037). Conclusion. We found a trend toward increased complication rates with thicker ADMs. In the future, larger prospective studies evaluating thickness may provide more information. PMID:27190645

  10. Glycerolized Reticular Dermis as a New Human Acellular Dermal Matrix: An Exploratory Study

    PubMed Central

    Ferrando, Pietro Maria; Balmativola, Davide; Cambieri, Irene; Scalzo, Maria Stella; Bergallo, Massimiliano; Annaratone, Laura; Casarin, Stefania; Fumagalli, Mara; Stella, Maurizio; Sapino, Anna; Castagnoli, Carlotta

    2016-01-01

    Human Acellular Dermal Matrices (HADM) are employed in various reconstructive surgery procedures as scaffolds for autologous tissue regeneration. The aim of this project was to develop a new type of HADM for clinical use, composed of glycerolized reticular dermis decellularized through incubation and tilting in Dulbecco’s Modified Eagle’s Medium (DMEM). This manufacturing method was compared with a decellularization procedure already described in the literature, based on the use of sodium hydroxide (NaOH), on samples from 28 donors. Cell viability was assessed using an MTT assay and microbiological monitoring was performed on all samples processed after each step. Two surgeons evaluated the biomechanical characteristics of grafts of increasing thickness. The effects of the different decellularization protocols were assessed by means of histological examination and immunohistochemistry, and residual DNA after decellularization was quantified using a real-time TaqMan MGB probe. Finally, we compared the results of DMEM based decellularization protocol on reticular dermis derived samples with the results of the same protocol applied on papillary dermis derived grafts. Our experimental results indicated that the use of glycerolized reticular dermis after 5 weeks of treatment with DMEM results in an HADM with good handling and biocompatibility properties. PMID:26918526

  11. Formation of acellular cementum-like layers, with and without extrinsic fiber insertion, along inert bone surfaces of aging c-Src gene knockout mice.

    PubMed

    Baba, Otto; Miyata, Atsushi; Abe, Tatsuhiko; Shibata, Shunichi; Nakano, Yukiko; Terashima, Tatsuo; Oda, Tsuyoshi; Kudo, Akira; Takano, Yoshiro

    2006-12-01

    To investigate the long-term effects of c-src deficiency on skeletal and dental tissues, we examined the lower jaws and long bones of c-src gene knockout (c-src KO) mice by histological and histochemical methods. Numerous multinucleated osteoclasts were distributed throughout the mandible in 5-wk-old c-src KO mice, but by 14 wk they had almost completely disappeared from the alveolar bone, leaving tartrate-resistant acid phosphatase (TRAP)-positive layers along the bone surface. Deposition of osteopontin-positive mineralized tissue, reminiscent of acellular afibrillar cementum (AAC), was confirmed along the TRAP-positive bone surface at 14 wk. The layer progressively thickened up to 21 months. A comparable mineralized layer was noted along the trabeculae of long bones as thickened cement lines. In the periostin-rich areas of jaw bones, but not in the long bones, portions of AAC-like mineralized layers were often replaced with and/or covered by acellular extrinsic fiber cementum (AEFC)-like tissue. These data suggest that the deposition of AAC-like mineralized tissue is a general phenomenon that may occur along inert or slowly remodeling bone surfaces under conditions characterized by reduced bone-resorbing activity, whereas the induction of AEFC-like tissue seems to be associated with the expression of certain molecules that are particularly abundant in the microenvironment of the periodontal ligament. PMID:17184236

  12. Incidence of Seromas and Infections Using Fenestrated versus Nonfenestrated Acellular Dermal Matrix in Breast Reconstructions

    PubMed Central

    Palaia, David A.; Arthur, Karen S.; Cahan, Anthony C.

    2015-01-01

    Background: Acellular dermal matrices (ADMs) provide clinical benefits in breast reconstruction but have been associated with increased postoperative complications, most frequently seromas. Fenestration of the ADM before insertion into the reconstructed breast may reduce the incidence of postoperative complications. In this retrospective analysis, postoperative complications were assessed after breast reconstruction with or without fenestrated ADMs. Methods: Patients who underwent immediate 2-staged implant breast reconstructions using ADM at a single center were assessed. The number of reconstructed breasts was stratified by ADM fenestration status and ADM type. The incidence of seroma, infection, extrusion, and explantation, and cosmetic score, was compared within the 2 stratified groups. A multivariable regression was performed to identify independent risk factors associated with these complications and aesthetic outcome. Results: In total, data from 450 patients who had 603 breast reconstructions using either AlloDerm or FlexHD demonstrated a significantly higher incidence of seroma with nonfenestrated ADMs (20%) versus fenestrated ADMs (11%; P = 0.0098). Rates of infection and explantation, and cosmetic score, were not influenced by fenestration status. In the multivariable analysis, ADM fenestration remained a significant protective factor for seroma formation. FlexHD also yielded a lower incidence of extrusion (P = 0.0031) and a higher cosmetic score (P = 0.0466) compared with AlloDerm after adjusting for other risk factors. Conclusions: The results of this study support ADM fenestration for reduction of seroma incidence in breast reconstruction, without affecting cosmetic results. Additionally, the choice of ADM may reduce extrusion incidence and improve aesthetic outcomes. PMID:26893994

  13. A New Approach to Minimize Acellular Dermal Matrix Use in Prosthesis-based Breast Reconstruction

    PubMed Central

    Hadad, Ivan; Liu, Allen S.

    2015-01-01

    Background: Acellular dermal matrices (ADMs) are often used to improve lower-pole contour, as well as allow for single-stage reconstruction, but numerous studies have shown an increased complication rate using ADM. As such, our group has developed a minimal-ADM-use technique to lower complications while effectively recreating lower-pole contour. Methods: A total of 380 postmastectomy prosthesis-based breast reconstructions were performed in 265 patients by a single surgeon. One hundred eight reconstructions were performed using the traditional ADM technique, with a large piece of ADM along the entire inferior and lateral borders. Two hundred twenty-five reconstructions were performed with the minimal-use technique, patching only the lateral area of the reconstruction. Thirty-five reconstructions were performed without the use of any ADM for high-risk reconstructions, most often in morbidly obese patients. Results: Comparing the traditional technique with the minimal-use technique, the seroma rate dropped from 3% to 0%. The rate of infection and reconstruction loss fell from 9% to 1%. Upon greatly reducing or eliminating the use of ADM use in obese patients, the seroma rate decreased from 15.4% to 5.7%, and the reconstruction loss rate decreased from 38% to 9%. Conclusions: This article describes a new surgical approach to minimize the amount of ADM necessary to create an aesthetically pleasing breast reconstruction. We believe that this approach helps avoid the complications of seroma, infection, and loss of the reconstruction. In certain obese patients, total avoidance of ADM may be the better choice. PMID:26301161

  14. Maxillary sinus augmentation using recombinant bone morphogenetic protein-2/acellular collagen sponge in combination with a mineralized bone replacement graft: a report of three cases.

    PubMed

    Tarnow, Dennis P; Wallace, Stephen S; Testori, Tiziano; Froum, Stuart J; Motroni, Alessandro; Prasad, Hari S

    2010-04-01

    The objective of the following case reports was to assess whether mineralized bone replacement grafts (eg, xenografts and allografts) could be added to recombinant human bone morphogenetic protein-2/acellular collagen sponge (rhBMP-2/ACS) in an effective manner that would: (1) reduce the graft shrinkage observed when using rhBMP-2/ACS alone, (2) reduce the volume and dose of rhBMP-2 required, and (3) preserve the osteoinductivity that rhBMP-2/ACS has shown when used alone. The primary outcome measures were histomorphometric analysis of vital bone production and analysis of serial computed tomographic scans to determine changes in bone graft density and stability. Over the 6-month course of this investigation, bone graft densities tended to increase (moreso with the xenograft than the allograft). The increased density in allograft cases was likely the result of both compression of the mineralized bone replacement graft and vital bone formation, seen histologically. Loss of volume was greater with the four-sponge dose than the two-sponge dose because of compression and resorption of the sponges. Vital bone formation in the allograft cases ranged from 36% to 53% but, because of the small sample size, it was not possible to determine any significant difference between the 5.6 mL (four-sponge) dose and the 2.8 mL (two-sponge) dose. Histology revealed robust new woven bone formation with only minimal traces of residual allograft, which appeared to have undergone accelerated remodeling or rhBMP-2-mediated resorption. PMID:20228973

  15. Human Lung Cancer Cells Grown on Acellular Rat Lung Matrix Create Perfusable Tumor Nodules

    PubMed Central

    Mishra, Dhruva K.; Thrall, Michael J.; Baird, Brandi N.; Ott, Harald C.; Blackmon, Shanda H.; Kurie, Jonathan M.; Kim, Min P.

    2015-01-01

    Background Extracellular matrix allows lung cancer to form its shape and grow. Recent studies on organ reengineering for orthotopic transplantation have provided a new avenue for isolating purified native matrix to use for growing cells. Whether human lung cancer cells grown in a decellularized rat lung matrix would create perfusable human lung cancer nodules was tested. Methods Rat lungs were harvested and native cells were removed using sodium dodecyl sulfate and Triton X-100 in a decellularization chamber to create a decellularized rat lung matrix. Human A549, H460, or H1299 lung cancer cells were placed into the decellularized rat lung matrix and grown in a customized bioreactor with perfusion of oxygenated media for 7 to 14 days. Results Decellularized rat lung matrix showed preservation of matrix architecture devoid of all rat cells. All three human lung cancer cell lines grown in the bioreactor developed tumor nodules with intact vasculature. Moreover, the lung cancer cells developed a pattern of growth similar to the original human lung cancer. Conclusions Overall, this study shows that human lung cancer cells form perfusable tumor nodules in a customized bioreactor on a decellularized rat lung matrix created by a customized decellularization chamber. The lung cancer cells grown in the matrix had features similar to the original human lung cancer. This ex vivo model can be used potentially to gain a deeper understanding of the biologic processes involved in human lung cancer. PMID:22385822

  16. Xenogenic (porcine) acellular dermal matrix promotes growth of granulation tissues in the wound healing of Fournier gangrene.

    PubMed

    Zhang, Zhaoxin; Lv, Lei; Mamat, Masut; Chen, Zhao; Zhou, Zhitao; Liu, Lihua; Wang, Zhizhong

    2015-01-01

    This article investigates the application values of Xenogenic (porcine) acellular dermal matrix (XADM) in preparation of a Fournier gangrene wound bed. Thirty-six consecutive cases of patients with Fournier gangrene between 2002 and 2012 were enrolled in our department of our hospital. The patients were divided into two groups according to different methods of wound bed preparation after surgical débridement, including the experimental group (17 cases) and the control group (19 cases). The wounds in the experimental group were covered with XADM after surgical wound débridement, whereas the wounds were cleaned with hydrogen peroxide and sodium hypochlorite solution (one time/day) in the control group. The wound bed preparation time and hospital stay were then compared in the two groups. The wound preparation time was 13.64 ± 1.46 days and hospitalization period was 26.06 ± 0.83 days in the experimental XADM group. In the control group, the wound bed preparation time and hospitalization period were 22.37 ± 1.38 and 38.11 ± 5.60 days, respectively. The results showed statistical differences between these two groups. When used in wound débridement after Fournier gangrene, XADM protects interecological organizations, promotes the growth of granulation tissues, and maximally retains function and morphology of the perineum and penis. PMID:25569072

  17. Dentin Matrix Proteins in Bone Tissue Engineering.

    PubMed

    Ravindran, Sriram; George, Anne

    2015-01-01

    Dentin and bone are mineralized tissue matrices comprised of collagen fibrils and reinforced with oriented crystalline hydroxyapatite. Although both tissues perform different functionalities, they are assembled and orchestrated by mesenchymal cells that synthesize both collagenous and noncollagenous proteins albeit in different proportions. The dentin matrix proteins (DMPs) have been studied in great detail in recent years due to its inherent calcium binding properties in the extracellular matrix resulting in tissue calcification. Recent studies have shown that these proteins can serve both as intracellular signaling proteins leading to induction of stem cell differentiation and also function as nucleating proteins in the extracellular matrix. These properties make the DMPs attractive candidates for bone and dentin tissue regeneration. This chapter will provide an overview of the DMPs, their functionality and their proven and possible applications with respect to bone tissue engineering.

  18. Bone Matrix Turnover And Balance In Vitro

    PubMed Central

    Flanagan, Barry; Nichols, George

    1969-01-01

    Labeled proline from incubation media has been shown to be incorporated into living bone matrix collagen in vitro. Hydroxyproline is released from fresh bone slices in similar systems in a characteristic curve against time. This hydroxyproline is derived from three distinct sources, each of which may be separately quantitated. Part of the total represents passive solubilization of matrix collagen, part is derived from new synthesis of soluble collagen occurring in vitro, and the remainder is released by cell-mediated resorptive action. The latter two processes are linear with time up to 8 hr; the former decays to zero at about 2 hr. Consequently, rates of collagen synthesis and of new collagen deposition and resorption can be quantitated simultaneously in the same system. The ability to measure these parameters of bone collagen metabolism provides methods both for the accurate evaluation of organic matrix resorption in vitro and for the accurate measurement of rates of collagen synthesis and collagen deposition. The application of the method is illustrated using parathyroid hormone and thyrocalcitonin. Parathyroid hormone diminishes collagen synthesis and stimulates collagen resorption. It reduces slightly the deposition of newly formed collagen in stable matrix. The net effect of these changes is to produce a marked negative balance. It does not significantly affect the solubility of matrix collagen. Thyrocalcitonin does not affect collagen synthesis or its deposition. It causes a marked fall in resorption rate. It has no effect on matrix collagen solubility. The net effect is to produce a marked positive balance of matrix collagen. Images PMID:5774102

  19. Own Experience From The Use Of A Substitute Of An Allogeneic Acellular Dermal Matrix Revitalized With In Vitro Cultured Skin Cells In Clinical Practice.

    PubMed

    Łabuś, Wojciech; Kawecki, Marek; Glik, Justyna; Maj, Mariusz; Kitala, Diana; Misiuga, Marcelina; Klama-Baryła, Agnieszka; Kraut, Małgorzata; Nowak, Mariusz

    2015-10-01

    As a result of the removal of cells from human allogeneic dermis, a collagen scaffold is obtained, which can be populated de novo with autologous/allogeneic skin cells and transplanted onto the area of skin loss. The optimal method for production of acellular dermal matrices (ADM) has been selected. Three female patients (a mean age of 54 years) were subjected to the transplantation of either autologous or allogeneic keratinocytes and fibroblasts into the holes of acellular dermal matrix (ADM) mesh graft. The method for burn wound treatment based on the use of a viable dermal-epidermal skin substitute (based on ADM and in vitro cultured fibroblasts and keratinocytes) may be the optimal method of burn treatment. PMID:26812752

  20. Own Experience From The Use Of A Substitute Of An Allogeneic Acellular Dermal Matrix Revitalized With In Vitro Cultured Skin Cells In Clinical Practice.

    PubMed

    Łabuś, Wojciech; Kawecki, Marek; Glik, Justyna; Maj, Mariusz; Kitala, Diana; Misiuga, Marcelina; Klama-Baryła, Agnieszka; Kraut, Małgorzata; Nowak, Mariusz

    2015-10-01

    As a result of the removal of cells from human allogeneic dermis, a collagen scaffold is obtained, which can be populated de novo with autologous/allogeneic skin cells and transplanted onto the area of skin loss. The optimal method for production of acellular dermal matrices (ADM) has been selected. Three female patients (a mean age of 54 years) were subjected to the transplantation of either autologous or allogeneic keratinocytes and fibroblasts into the holes of acellular dermal matrix (ADM) mesh graft. The method for burn wound treatment based on the use of a viable dermal-epidermal skin substitute (based on ADM and in vitro cultured fibroblasts and keratinocytes) may be the optimal method of burn treatment.

  1. [Osteoplastic effectiveness of mineralized bone matrix].

    PubMed

    2013-01-01

    In the experiment conducted on 50 Wistar rats, the peculiarities of the reparative osteogenesis were studied using scanning electron microscopy, x-ray electron-probe microanalysis and histological techniques. Granulated mineralized bone matrix (MBM) obtained without thermal and demineralizing treatment, was implanted into the tibial defect. MBM was found to possess marked osteoinductive and osteoconductive properties. It induced a prolonged activation of reparative osteogenesis after the implantation, as well as deep bone tissue ingrowth into the implant, acceleration of organotypic remodeling of regenerated bone, intense angiogenesis and early restoration of the damaged

  2. [Osteoplastic effectiveness of mineralized bone matrix].

    PubMed

    2013-01-01

    In the experiment conducted on 50 Wistar rats, the peculiarities of the reparative osteogenesis were studied using scanning electron microscopy, x-ray electron-probe microanalysis and histological techniques. Granulated mineralized bone matrix (MBM) obtained without thermal and demineralizing treatment, was implanted into the tibial defect. MBM was found to possess marked osteoinductive and osteoconductive properties. It induced a prolonged activation of reparative osteogenesis after the implantation, as well as deep bone tissue ingrowth into the implant, acceleration of organotypic remodeling of regenerated bone, intense angiogenesis and early restoration of the damaged PMID:23805618

  3. Management of a Giant Omphalocele with Non–Cross-Linked Intact Porcine-Derived Acellular Dermal Matrix (Strattice) Combined with Vacuum Therapy

    PubMed Central

    Travassos, Daisy Vieira; van Eerde, Albertien M.; Kramer, William L.M.

    2015-01-01

    The management of giant omphaloceles at our department is primarily conservative. However, management can be challenging if the omphalocele is ruptured or the sac has to be removed. We report a case in which a giant omphalocele in a newborn female patient was managed by covering the abdominal defect with non–cross-linked intact porcine-derived acellular dermal matrix (Strattice reconstructive tissue matrix, LifeCell Corp., Branchburg, New Jersey, United States) sutured to the fascia combined with vacuum therapy. PMID:26788448

  4. Management of a Giant Omphalocele with Non-Cross-Linked Intact Porcine-Derived Acellular Dermal Matrix (Strattice) Combined with Vacuum Therapy.

    PubMed

    Travassos, Daisy Vieira; van Eerde, Albertien M; Kramer, William L M

    2015-12-01

    The management of giant omphaloceles at our department is primarily conservative. However, management can be challenging if the omphalocele is ruptured or the sac has to be removed. We report a case in which a giant omphalocele in a newborn female patient was managed by covering the abdominal defect with non-cross-linked intact porcine-derived acellular dermal matrix (Strattice reconstructive tissue matrix, LifeCell Corp., Branchburg, New Jersey, United States) sutured to the fascia combined with vacuum therapy. PMID:26788448

  5. Cancellous bone repair using bovine trabecular bone matrix particulates.

    PubMed

    Mushipe, M T; Revell, P A; Shelton, J C

    2002-01-01

    At 5 and 15 weeks post-surgery, biomechanical and histological analyses of cancellous bone defects filled with the bovine trabecular bone matrix (BBM) and hydroxyapatite (Hap) particulates of dimensions 106-150 microm were investigated. It was observed that at 5 weeks post-surgery the stiffness properties of the BBM filled defects were significantly higher than those observed in the Hap filled defects (p < 0.01) but comparable to those recorded in intact cancellous bone from the same anatomical position. Histologically, no significant differences were observed in the percentage of new bone contact with the particles. The biomechanical properties of the Hap filled defects mirrored those in intact cancellous bone only at 15 weeks post-surgery. BBM particles thus appeared to accelerate the early healing of osteotomies. It is therefore suggested that particles of this bioceramic be the subject of intense research for more usage in both periodontal osseous defects and orthopaedic fractures.

  6. Biomimetically enhanced demineralized bone matrix for bone regenerative applications

    PubMed Central

    Ravindran, Sriram; Huang, Chun-Chieh; Gajendrareddy, Praveen; Narayanan, Raghuvaran

    2015-01-01

    Demineralized bone matrix (DBM) is one of the most widely used bone graft materials in dentistry. However, the ability of DBM to reliably and predictably induce bone regeneration has always been a cause for concern. The quality of DBM varies greatly depending on several donor dependent factors and also manufacturing techniques. In order to standardize the quality and to enable reliable and predictable bone regeneration, we have generated a biomimetically-enhanced version of DBM (BE-DBM) using clinical grade commercial DBM as a control. We have generated the BE-DBM by incorporating a cell-derived pro-osteogenic extracellular matrix (ECM) within clinical grade DBM. In the present study, we have characterized the BE-DBM and evaluated its ability to induce osteogenic differentiation of human marrow derived stromal cells (HMSCs) with respect to clinical grade commercial DBM. Our results indicate that the BE-DBM contains significantly more pro-osteogenic factors than DBM and enhances HMSC differentiation and mineralized matrix formation in vitro and in vivo. Based on our results, we envision that the BE-DBM has the potential to replace DBM as the bone graft material of choice. PMID:26557093

  7. Targeted delivery of adipose-derived stem cells via acellular dermal matrix enhances wound repair in diabetic rats.

    PubMed

    Nie, Chunlei; Zhang, Guoyou; Yang, Daping; Liu, Tong; Liu, Dan; Xu, Jin; Zhang, Jiewu

    2015-03-01

    Cell-based therapeutic intervention has emerged as a new approach to accelerate wound closure. Adipose-derived stem cells (ASCs), as a fascinating cell source, have received much attention in tissue repair and regeneration. In this study we evaluated the potential of acellular dermal matrix (ADM) scaffold serving as a carrier for the delivery of ASCs and investigated its therapeutic effects on wound healing. First, ASCs were isolated and characterized for multidifferentiation potential. ASCs-ADM grafts were then prepared, and ADM scaffold was shown to support the in vitro growth and proliferation of ASCs. Next, we analysed paracrine factors in conditioned medium and found that ASCs-ADM grafts secreted various cytokines, including VEGF, HGF, TGFβ and bFGF. Moreover, ASCs-ADM conditioned medium notably stimulated the migration and proliferation of fibroblasts. In vivo, we established an excisional wound model in diabetic rats which received phosphate-buffered saline (PBS), ADM or ASCs-ADM grafts, respectively. Our results demonstrated that implantation of ASCs-ADM significantly enhanced tissue regeneration and increased epithelialization, resulting in accelerated wound closure. Immunofluorescence analysis further indicated that capillary density was evidently increased in the ASCs-ADM group compared with the control or ADM group. In addition, western blot analysis showed that ASCs-ADM significantly increased the expression of angiogenic factors, which was consistent with in vitro data. Taken together, our results suggest that targeted delivery of ASCs via ADM scaffold accelerate diabetic wound healing through a paracrine mechanism, with enhanced granulation tissue formation and increased re-epithelialization and neovascularization.

  8. Human Acellular Dermal Matrix Paired With Silver-zinc Coupled Electroceutical Dressing Results in Rapid Healing of Complicated Diabetic Wounds of Mixed Etiology: A Novel Case Series.

    PubMed

    Cole, Windy

    2016-07-01

    Patients with diabetes are well known for having difficult-to-close wounds. When additional factors are added, such as gouty tophi or tumors, the difficulty is compounded and conventional care often fails to heal the wound. In this case series, an innovative wound modality that combined a human acellular dermal matrix with a silver-zinc coupled electroceutical wound dressing was used in 3 particularly difficult and complex cases. In all 3 cases, this alternative treatment provided full healing within 6 weeks in wounds that conventional care had been unable to close in up to 2 years. PMID:27428719

  9. Thick Acellular Heart Extracellular Matrix with Inherent Vasculature: A Potential Platform for Myocardial Tissue Regeneration

    PubMed Central

    Sarig, Udi; Au-Yeung, Gigi C.T.; Wang, Yao; Bronshtein, Tomer; Dahan, Nitsan; Boey, Freddy Y.C.; Venkatraman, Subbu S.

    2012-01-01

    The decellularization of porcine heart tissue offers many opportunities for the production of physiologically relevant myocardial mimetic scaffolds. Earlier, we reported the successful isolation of a thin porcine cardiac extracellular matrix (pcECM) exhibiting relevant bio-mechanical properties for myocardial tissue engineering. Nevertheless, since native cardiac tissue is much thicker, such thin scaffolds may offer limited regeneration capacity. However, generation of thicker myocardial mimetic tissue constructs is hindered by diffusion limitations (∼100 μm), and the lack of a proper vascular-like network within these constructs. In our present work, we focused on optimizing the decellularization procedure for thicker tissue slabs (10–15 mm), while retaining their inherent vasculature, and on characterizing the resulting pcECM. The trypsin/Triton-based perfusion procedure that resulted in a nonimmunogenic and cell-supportive pcECM was found to be more effective in cell removal and in the preservation of fiber morphology and structural characteristics than stirring, sonication, or sodium dodecyl sulfate/Triton-based procedures. Mass spectroscopy revealed that the pcECM is mainly composed of ECM proteins with no apparent cellular protein remains. Mechanical testing indicated that the obtained pcECM is viscoelastic in nature and possesses the typical stress-strain profile of biological materials. It is stiffer than native tissue yet exhibits matched mechanical properties in terms of energy dissipation, toughness, and ultimate stress behavior. Vascular network functionality was maintained to the first three–four branches from the main coronary vessels. Taken together, these results reaffirm the efficiency of the decellularization procedure reported herein for yielding thick nonimmunogenic cell-supportive pcECM scaffolds, preserving both native tissue ultra-structural properties and an inherent vascular network. When reseeded with the appropriate progenitor

  10. Healing rate and autoimmune safety of full-thickness wounds treated with fish skin acellular dermal matrix versus porcine small-intestine submucosa: a noninferiority study.

    PubMed

    Baldursson, Baldur Tumi; Kjartansson, Hilmar; Konrádsdóttir, Fífa; Gudnason, Palmar; Sigurjonsson, Gudmundur F; Lund, Sigrún Helga

    2015-03-01

    A novel product, the fish skin acellular dermal matrix (ADM) has recently been introduced into the family of biological materials for the treatment of wounds. Hitherto, these products have been produced from the organs of livestock. A noninferiority test was used to compare the effect of fish skin ADM against porcine small-intestine submucosa extracellular matrix in the healing of 162 full-thickness 4-mm wounds on the forearm of 81 volunteers. The fish skin product was noninferior at the primary end point, healing at 28 days. Furthermore, the wounds treated with fish skin acellular matrix healed significantly faster. These results might give the fish skin ADM an advantage because of its environmental neutrality when compared with livestock-derived products. The study results on these acute full-thickness wounds might apply for diabetic foot ulcers and other chronic full-thickness wounds, and the shorter healing time for the fish skin-treated group could influence treatment decisions. To test the autoimmune reactivity of the fish skin, the participants were tested with the following ELISA (enzyme-linked immunosorbent assay) tests: RF, ANA, ENA, anti ds-DNA, ANCA, anti-CCP, and anticollagen I and II. These showed no reactivity. The results demonstrate the claims of safety and efficacy of fish skin ADM for wound care.

  11. Time-dependent bladder tissue regeneration using bilayer bladder acellular matrix graft-silk fibroin scaffolds in a rat bladder augmentation model.

    PubMed

    Zhao, Yang; He, Yi; Zhou, Zhe; Guo, Jian-hua; Wu, Jia-sheng; Zhang, Ming; Li, Wei; Zhou, Juan; Xiao, Dong-dong; Wang, Zhong; Sun, Kang; Zhu, Ying-jian; Lu, Mu-jun

    2015-09-01

    With advances in tissue engineering, various synthetic and natural biomaterials have been widely used in tissue regeneration of the urinary bladder in rat models. However, reconstructive procedures remain insufficient due to the lack of appropriate scaffolding, which should provide a waterproof barrier function and support the needs of various cell types. To address these problems, we have developed a bilayer scaffold comprising a porous network (silk fibroin [SF]) and an underlying natural acellular matrix (bladder acellular matrix graft [BAMG]) and evaluated its feasibility and potential for bladder regeneration in a rat bladder augmentation model. Histological (hematoxylin and eosin and Masson's trichrome staining) and immunohistochemical analyses demonstrated that the bilayer BAMG-SF scaffold promoted smooth muscle, blood vessel, and nerve regeneration in a time-dependent manner. At 12weeks after implantation, bladders reconstructed with the BAMG-SF matrix displayed superior structural and functional properties without significant local tissue responses or systemic toxicity. These results demonstrated that the bilayer BAMG-SF scaffold may be a promising scaffold with good biocompatibility for bladder regeneration in the rat bladder augmentation model.

  12. Time-dependent bladder tissue regeneration using bilayer bladder acellular matrix graft-silk fibroin scaffolds in a rat bladder augmentation model.

    PubMed

    Zhao, Yang; He, Yi; Zhou, Zhe; Guo, Jian-hua; Wu, Jia-sheng; Zhang, Ming; Li, Wei; Zhou, Juan; Xiao, Dong-dong; Wang, Zhong; Sun, Kang; Zhu, Ying-jian; Lu, Mu-jun

    2015-09-01

    With advances in tissue engineering, various synthetic and natural biomaterials have been widely used in tissue regeneration of the urinary bladder in rat models. However, reconstructive procedures remain insufficient due to the lack of appropriate scaffolding, which should provide a waterproof barrier function and support the needs of various cell types. To address these problems, we have developed a bilayer scaffold comprising a porous network (silk fibroin [SF]) and an underlying natural acellular matrix (bladder acellular matrix graft [BAMG]) and evaluated its feasibility and potential for bladder regeneration in a rat bladder augmentation model. Histological (hematoxylin and eosin and Masson's trichrome staining) and immunohistochemical analyses demonstrated that the bilayer BAMG-SF scaffold promoted smooth muscle, blood vessel, and nerve regeneration in a time-dependent manner. At 12weeks after implantation, bladders reconstructed with the BAMG-SF matrix displayed superior structural and functional properties without significant local tissue responses or systemic toxicity. These results demonstrated that the bilayer BAMG-SF scaffold may be a promising scaffold with good biocompatibility for bladder regeneration in the rat bladder augmentation model. PMID:26049152

  13. Molecular examination of bone marrow stromal cells and chondroitinase ABC-assisted acellular nerve allograft for peripheral nerve regeneration

    PubMed Central

    Wang, Ying; Jia, Hua; Li, Wen-Yuan; Guan, Li-Xin; Deng, Lingxiao; Liu, Yan-Cui; Liu, Gui-Bo

    2016-01-01

    The present study aimed to evaluate the molecular mechanisms underlying combinatorial bone marrow stromal cell (BMSC) transplantation and chondroitinase ABC (Ch-ABC) therapy in a model of acellular nerve allograft (ANA) repair of the sciatic nerve gap in rats. Sprague Dawley rats (n=24) were used as nerve donors and Wistar rats (n=48) were randomly divided into the following groups: Group I, Dulbecco's modified Eagle's medium (DMEM) control group (ANA treated with DMEM only); Group II, Ch-ABC group (ANA treated with Ch-ABC only); Group III, BMSC group (ANA seeded with BMSCs only); Group IV, Ch-ABC + BMSCs group (Ch-ABC treated ANA then seeded with BMSCs). After 8 weeks, the expression of nerve growth factor, brain-derived neurotrophic factor and vascular endothelial growth factor in the regenerated tissues were detected by reverse transcription-quantitative polymerase chain reaction and immunohistochemistry. Axonal regeneration, motor neuron protection and functional recovery were examined by immunohistochemistry, horseradish peroxidase retrograde neural tracing and electrophysiological and tibialis anterior muscle recovery analyses. It was observed that combination therapy enhances the growth response of the donor nerve locally as well as distally, at the level of the spinal cord motoneuron and the target muscle organ. This phenomenon is likely due to the propagation of retrograde and anterograde transport of growth signals sourced from the graft site. Collectively, growth improvement on the donor nerve, target muscle and motoneuron ultimately contribute to efficacious axonal regeneration and functional recovery. Thorough investigation of molecular peripheral nerve injury combinatorial strategies are required for the optimization of efficacious therapy and full functional recovery following ANA. PMID:27698684

  14. Molecular examination of bone marrow stromal cells and chondroitinase ABC-assisted acellular nerve allograft for peripheral nerve regeneration

    PubMed Central

    Wang, Ying; Jia, Hua; Li, Wen-Yuan; Guan, Li-Xin; Deng, Lingxiao; Liu, Yan-Cui; Liu, Gui-Bo

    2016-01-01

    The present study aimed to evaluate the molecular mechanisms underlying combinatorial bone marrow stromal cell (BMSC) transplantation and chondroitinase ABC (Ch-ABC) therapy in a model of acellular nerve allograft (ANA) repair of the sciatic nerve gap in rats. Sprague Dawley rats (n=24) were used as nerve donors and Wistar rats (n=48) were randomly divided into the following groups: Group I, Dulbecco's modified Eagle's medium (DMEM) control group (ANA treated with DMEM only); Group II, Ch-ABC group (ANA treated with Ch-ABC only); Group III, BMSC group (ANA seeded with BMSCs only); Group IV, Ch-ABC + BMSCs group (Ch-ABC treated ANA then seeded with BMSCs). After 8 weeks, the expression of nerve growth factor, brain-derived neurotrophic factor and vascular endothelial growth factor in the regenerated tissues were detected by reverse transcription-quantitative polymerase chain reaction and immunohistochemistry. Axonal regeneration, motor neuron protection and functional recovery were examined by immunohistochemistry, horseradish peroxidase retrograde neural tracing and electrophysiological and tibialis anterior muscle recovery analyses. It was observed that combination therapy enhances the growth response of the donor nerve locally as well as distally, at the level of the spinal cord motoneuron and the target muscle organ. This phenomenon is likely due to the propagation of retrograde and anterograde transport of growth signals sourced from the graft site. Collectively, growth improvement on the donor nerve, target muscle and motoneuron ultimately contribute to efficacious axonal regeneration and functional recovery. Thorough investigation of molecular peripheral nerve injury combinatorial strategies are required for the optimization of efficacious therapy and full functional recovery following ANA.

  15. Acellular dermal matrix allograft used alone and in combination with enamel matrix protein in gingival recession: histologic study in dogs.

    PubMed

    de Oliveira, Cristiane Aparecida; Spolidório, Luís Carlos; Cirelli, Joni Augusto; Marcantonio, Roseemary Adriana Chiérici

    2005-12-01

    Gingival recession was created in six mongrel dogs. The dogs were divided into two groups based on treatment: group 1--AlloDerm only, group 2--AlloDerm + Emdogain. The histologic results were compared. At the end of the study, the mean values were, for groups 1 and 2, respectively: 0.06 and 0.32 mm for cementum regeneration; -0.75 and -0.86 mm for bone regeneration; -2.15 and -3.11 mm for attachment level; and 4.90 and 5.51 mm for defect extent. The epithelial formation parameter was 2.88 mm in group 1 and 2.15 mm in group 2, which was a statistically significant difference. It could be concluded that Emdogain did not result in beneficial effects when associated with AlloDerm. PMID:16353534

  16. Nerve Wrapping of the Sciatic Nerve With Acellular Dermal Matrix in Chronic Complete Proximal Hamstring Ruptures and Ischial Apophyseal Avulsion Fractures

    PubMed Central

    Haus, Brian M.; Arora, Danny; Upton, Joseph; Micheli, Lyle J.

    2016-01-01

    Background: Patients with chronic injuries of the proximal hamstring can develop significant impairment because of weakness of the hamstring muscles, sciatic nerve compression from scar formation, or myositis ossificans. Purpose: To describe the surgical outcomes of patients with chronic injury of the proximal hamstrings who were treated with hamstring repair and sciatic neurolysis supplemented with nerve wrapping with acellular dermal matrix. Study Design: Retrospective case series; Level of evidence, 4. Methods: Fifteen consecutive patients with a diagnosis of chronic complete proximal hamstring rupture or chronic ischial tuberosity apophyseal avulsion fracture (mean age, 39.67 years; range, 14-69 years) were treated with proximal hamstring repair and sciatic neurolysis supplemented with nerve wrapping with acellular dermal matrix. Nine patients had preoperative sciatica, and 6 did not. Retrospective chart review recorded clinical outcomes measured by the degree of pain relief, the rate of return to activities, and associated postoperative complications. Results: All 15 patients were followed in the postoperative period for an average of 16.6 months. Postoperatively, there were 4 cases of transient sciatic nerve neurapraxia. Four patients (26%) required postoperative betamethasone sodium phosphate (Celestone Soluspan) injectable suspension USP 6 mg/mL. Among the 9 patients with preoperative sciatica, 6 (66%) had a good or excellent outcome and were able to return to their respective activities/sports; 3 (33%) had persistent chronic pain. One of these had persistent sciatic neuropathy that required 2 surgical reexplorations and scar excision after development of recurrent extraneural scar formation. Among the 6 without preoperative sciatica, 100% had a good or excellent outcomes and 83% returned to their respective activities/sports. Better outcomes were observed in younger patients, as the 3 cases of persistent chronic sciatic pain were in patients older than 45

  17. The use of an acellular dermal regenerative tissue matrix in the treatment of lower extremity wounds: a prospective 16-week pilot study.

    PubMed

    Brigido, Stephen A

    2006-09-01

    A prospective, single-centre, randomized controlled study was performed to evaluate the effectiveness of Graftjacket, a human acellular regenerative tissue matrix as a treatment option for chronic non healing lower extremity wounds. Twenty-eight diabetic patients with full-thickness wounds that had been present for at least 6 weeks were treated with sharp debridement and randomized to a single application of Graftjacket tissue matrix plus mineral oil-soaked fluff compression dressing or to a control treatment of wound gel with gauze dressings. All patients were seen weekly. By week 16, 12 of 14 patients treated with Graftjacket tissue matrix demonstrated complete wound closure compared with 4 of 14 patients in the control group. Patients treated with Graftjacket tissue matrix showed a statistically significant higher percentage of wound healing with respect to wound area, and clinically significant differences in wound depth and wound volume. This comparison is not performed to demonstrate that the application of the Grafjacket is more effective than sharp debridement. This study is done to help assign a role to the use of Graftjacket matrix in lower extremity wound care.

  18. Combined periodontal and restorative approach to the treatment of gingival recessions with noncarious cervical lesions: a case treated with acellular dermal matrix allograft and compomer restorations.

    PubMed

    Efeoğlu, Ahmet; Hanzade, Mete; Sari, Esra; Alpay, Hande; Karakaş, Ozan; Koray, Fatma

    2012-08-01

    Treatment of gingival recessions has become one of the most challenging procedures in periodontal plastic surgery. Various surgical options with predictable outcomes are available, but in cases with cervical lesions or restorations, optimal functional and esthetic results may require the combination of periodontal and restorative procedures. In this case report, one patient treated with acellular dermal matrix allograft and a coronally positioned flap in combination with compomer cervical restorations is presented. Clinical parameters were recorded immediately prior to surgery and after 12 months. Postoperatively, significant root coverage, reductions in probing depths, and gains in clinical attachment were observed. The final clinical results, esthetics, color match, and tissue contours were acceptable to both the patient and clinicians. PMID:22577650

  19. Acellular Dermal Matrix Combined with Autologous Skin Grafts for Closure of Chronic Wounds after Reconstruction of Skull Defects with Titanium Mesh.

    PubMed

    Luo, Xu; Lin, Cai; Wang, Xinling; Lin, Xiangwei; He, Sunyue; Liu, Yunfeng; Zhang, Yong; Yang, Ruijin; Zhu, Xinguo

    2016-07-01

    Objective The closure of chronic wounds after skull defect reconstruction with titanium mesh is one of the most challenging problems for plastic and reconstructive surgeons. Current approaches are disappointing. Methods In 10 patients, we explored the role of acellular dermal matrix (ADM) in combination with autologous skin grafts (ASGs) for closure of chronic wounds after skull reconstruction with titanium. Results ADM and ASG survived in all patients. Grade A healing (healing well without defect) was achieved. The average operating time was 30 to 45 minutes, and the average blood loss 30 to 50 mL. After 3 months, the wound was still closed in all patients. Conclusion The combination of ADM plus ASG obtained a high wound closure rate. ADM plus ASG allows avoiding other procedures such as rotational flaps and free flaps that require more operating time, special equipment, and adequate training. PMID:27088591

  20. On the origin of intrinsic matrix of acellular extrinsic fiber cementum: studies on growing cementum pearls of normal and bisphosphonate-affected guinea pig molars.

    PubMed

    Jayawardena, Chantha K; Takahashi, Nobuyuki; Watanabae, Eiko; Takano, Yoshiro

    2002-06-01

    Cementum pearls (CPs) belong to a type of acellular extrinsic fiber cementum (AEFC) that form on the maturing enamel of guinea pig molars. This study aimed to elucidate the forming process of intrinsic matrix of AEFC using the CPs of normal and bisphosphonate-affected guinea pig molars as experimental models. A group of guinea pigs were subjected to continuous administration of 1-hydroxyethylidene-1,1-bisphosphonate (HEBP) for 2 wk to inhibit mineralization of growing CPs. Fenestration of the enamel organ and migration of periodontal cells on to the exposed surface of maturing enamel appeared to be unaffected by HEBP, whereas de novo formation as well as growth of pre-existing CPs did not proceed under the same conditions. Immunoreactions for osteopontin were located exclusively on the mineralized matrix of preformed CPs, implying the absence of additional deposition or accumulation of putative intrinsic cementum matrix on the affected CPs, where the propagation of mineral phase had been arrested. In both normal and HEBP-treated groups, distinct enzymatic reactions for alkaline phosphatase appeared on the cells of the periodontal ligament associated closely with the sites of CP formation, and along the mineralization front of CPs. These observations suggest that the mineralization process per se plays a central role in the deposition of AEFC matrix and that alkaline phosphatase of periodontal cells penetrating through the enamel organ to the maturing enamel surface plays a key role in the mineralization process of CPs. PMID:12120713

  1. Evaluation of the Antimicrobial Efficacy of a Novel Rifampin/Minocycline-Coated, Noncrosslinked Porcine Acellular Dermal Matrix Compared With Uncoated Scaffolds for Soft Tissue Repair.

    PubMed

    Majumder, Arnab; Scott, Jeffrey R; Novitsky, Yuri W

    2016-10-01

    Background Despite meticulous aseptic technique and systemic antibiotics, bacterial colonization of mesh remains a critical issue in hernia repair. A novel minocycline/rifampin tyrosine-coated, noncrosslinked porcine acellular dermal matrix (XenMatrix AB) was developed to protect the device from microbial colonization for up to 7 days. The objective of this study was to evaluate the in vitro and in vivo antimicrobial efficacy of this device against clinically isolated methicillin-resistant Staphylococcus aureus (MRSA) and Escherichia coli. Methods XenMatrix AB was compared with 5 existing uncoated soft tissue repair devices using in vitro methods of zone of inhibition (ZOI) and scanning electron microscopy (SEM) at 24 hours following inoculation with MRSA or E coli These devices were also evaluated at 7 days following dorsal implantation and inoculation with MRSA or E coli (60 male New Zealand white rabbits, n = 10 per group) for viable colony-forming units (CFU), abscess formation and histopathologic response, respectively. Results In vitro studies demonstrated a median ZOI of 36 mm for MRSA and 16 mm for E coli for XenMatrix AB, while all uncoated devices showed no inhibition of bacterial growth (0 mm). SEM also demonstrated no visual evidence of MRSA or E coli colonization on the surface of XenMatrix AB compared with colonization of all other uncoated devices. In vivo XenMatrix AB demonstrated complete inhibition of bacterial colonization, no abscess formation, and a reduced inflammatory response compared with uncoated devices. Conclusion We demonstrated that XenMatrix AB possesses potent in vitro and in vivo antimicrobial efficacy against clinically isolated MRSA and E coli compared with uncoated devices.

  2. Improved cartilage regeneration by implantation of acellular biomaterials after bone marrow stimulation: a systematic review and meta-analysis of animal studies

    PubMed Central

    Pot, Michiel W.; Gonzales, Veronica K.; Buma, Pieter; IntHout, Joanna

    2016-01-01

    Microfracture surgery may be applied to treat cartilage defects. During the procedure the subchondral bone is penetrated, allowing bone marrow-derived mesenchymal stem cells to migrate towards the defect site and form new cartilage tissue. Microfracture surgery generally results in the formation of mechanically inferior fibrocartilage. As a result, this technique offers only temporary clinical improvement. Tissue engineering and regenerative medicine may improve the outcome of microfracture surgery. Filling the subchondral defect with a biomaterial may provide a template for the formation of new hyaline cartilage tissue. In this study, a systematic review and meta-analysis were performed to assess the current evidence for the efficacy of cartilage regeneration in preclinical models using acellular biomaterials implanted after marrow stimulating techniques (microfracturing and subchondral drilling) compared to the natural healing response of defects. The review aims to provide new insights into the most effective biomaterials, to provide an overview of currently existing knowledge, and to identify potential lacunae in current studies to direct future research. A comprehensive search was systematically performed in PubMed and EMBASE (via OvidSP) using search terms related to tissue engineering, cartilage and animals. Primary studies in which acellular biomaterials were implanted in osteochondral defects in the knee or ankle joint in healthy animals were included and study characteristics tabulated (283 studies out of 6,688 studies found). For studies comparing non-treated empty defects to defects containing implanted biomaterials and using semi-quantitative histology as outcome measure, the risk of bias (135 studies) was assessed and outcome data were collected for meta-analysis (151 studies). Random-effects meta-analyses were performed, using cartilage regeneration as outcome measure on an absolute 0–100% scale. Implantation of acellular biomaterials significantly

  3. Improved cartilage regeneration by implantation of acellular biomaterials after bone marrow stimulation: a systematic review and meta-analysis of animal studies.

    PubMed

    Pot, Michiel W; Gonzales, Veronica K; Buma, Pieter; IntHout, Joanna; van Kuppevelt, Toin H; de Vries, Rob B M; Daamen, Willeke F

    2016-01-01

    Microfracture surgery may be applied to treat cartilage defects. During the procedure the subchondral bone is penetrated, allowing bone marrow-derived mesenchymal stem cells to migrate towards the defect site and form new cartilage tissue. Microfracture surgery generally results in the formation of mechanically inferior fibrocartilage. As a result, this technique offers only temporary clinical improvement. Tissue engineering and regenerative medicine may improve the outcome of microfracture surgery. Filling the subchondral defect with a biomaterial may provide a template for the formation of new hyaline cartilage tissue. In this study, a systematic review and meta-analysis were performed to assess the current evidence for the efficacy of cartilage regeneration in preclinical models using acellular biomaterials implanted after marrow stimulating techniques (microfracturing and subchondral drilling) compared to the natural healing response of defects. The review aims to provide new insights into the most effective biomaterials, to provide an overview of currently existing knowledge, and to identify potential lacunae in current studies to direct future research. A comprehensive search was systematically performed in PubMed and EMBASE (via OvidSP) using search terms related to tissue engineering, cartilage and animals. Primary studies in which acellular biomaterials were implanted in osteochondral defects in the knee or ankle joint in healthy animals were included and study characteristics tabulated (283 studies out of 6,688 studies found). For studies comparing non-treated empty defects to defects containing implanted biomaterials and using semi-quantitative histology as outcome measure, the risk of bias (135 studies) was assessed and outcome data were collected for meta-analysis (151 studies). Random-effects meta-analyses were performed, using cartilage regeneration as outcome measure on an absolute 0-100% scale. Implantation of acellular biomaterials significantly

  4. Improved cartilage regeneration by implantation of acellular biomaterials after bone marrow stimulation: a systematic review and meta-analysis of animal studies.

    PubMed

    Pot, Michiel W; Gonzales, Veronica K; Buma, Pieter; IntHout, Joanna; van Kuppevelt, Toin H; de Vries, Rob B M; Daamen, Willeke F

    2016-01-01

    Microfracture surgery may be applied to treat cartilage defects. During the procedure the subchondral bone is penetrated, allowing bone marrow-derived mesenchymal stem cells to migrate towards the defect site and form new cartilage tissue. Microfracture surgery generally results in the formation of mechanically inferior fibrocartilage. As a result, this technique offers only temporary clinical improvement. Tissue engineering and regenerative medicine may improve the outcome of microfracture surgery. Filling the subchondral defect with a biomaterial may provide a template for the formation of new hyaline cartilage tissue. In this study, a systematic review and meta-analysis were performed to assess the current evidence for the efficacy of cartilage regeneration in preclinical models using acellular biomaterials implanted after marrow stimulating techniques (microfracturing and subchondral drilling) compared to the natural healing response of defects. The review aims to provide new insights into the most effective biomaterials, to provide an overview of currently existing knowledge, and to identify potential lacunae in current studies to direct future research. A comprehensive search was systematically performed in PubMed and EMBASE (via OvidSP) using search terms related to tissue engineering, cartilage and animals. Primary studies in which acellular biomaterials were implanted in osteochondral defects in the knee or ankle joint in healthy animals were included and study characteristics tabulated (283 studies out of 6,688 studies found). For studies comparing non-treated empty defects to defects containing implanted biomaterials and using semi-quantitative histology as outcome measure, the risk of bias (135 studies) was assessed and outcome data were collected for meta-analysis (151 studies). Random-effects meta-analyses were performed, using cartilage regeneration as outcome measure on an absolute 0-100% scale. Implantation of acellular biomaterials significantly

  5. Improved cartilage regeneration by implantation of acellular biomaterials after bone marrow stimulation: a systematic review and meta-analysis of animal studies

    PubMed Central

    Pot, Michiel W.; Gonzales, Veronica K.; Buma, Pieter; IntHout, Joanna

    2016-01-01

    Microfracture surgery may be applied to treat cartilage defects. During the procedure the subchondral bone is penetrated, allowing bone marrow-derived mesenchymal stem cells to migrate towards the defect site and form new cartilage tissue. Microfracture surgery generally results in the formation of mechanically inferior fibrocartilage. As a result, this technique offers only temporary clinical improvement. Tissue engineering and regenerative medicine may improve the outcome of microfracture surgery. Filling the subchondral defect with a biomaterial may provide a template for the formation of new hyaline cartilage tissue. In this study, a systematic review and meta-analysis were performed to assess the current evidence for the efficacy of cartilage regeneration in preclinical models using acellular biomaterials implanted after marrow stimulating techniques (microfracturing and subchondral drilling) compared to the natural healing response of defects. The review aims to provide new insights into the most effective biomaterials, to provide an overview of currently existing knowledge, and to identify potential lacunae in current studies to direct future research. A comprehensive search was systematically performed in PubMed and EMBASE (via OvidSP) using search terms related to tissue engineering, cartilage and animals. Primary studies in which acellular biomaterials were implanted in osteochondral defects in the knee or ankle joint in healthy animals were included and study characteristics tabulated (283 studies out of 6,688 studies found). For studies comparing non-treated empty defects to defects containing implanted biomaterials and using semi-quantitative histology as outcome measure, the risk of bias (135 studies) was assessed and outcome data were collected for meta-analysis (151 studies). Random-effects meta-analyses were performed, using cartilage regeneration as outcome measure on an absolute 0–100% scale. Implantation of acellular biomaterials significantly

  6. Preservation of micro-architecture and angiogenic potential in a pulmonary acellular matrix obtained using intermittent intra-tracheal flow of detergent enzymatic treatment

    PubMed Central

    Maghsoudlou, Panagiotis; Georgiades, Fanourios; Tyraskis, Athanasios; Totonelli, Giorgia; Loukogeorgakis, Stavros P.; Orlando, Giuseppe; Shangaris, Panicos; Lange, Peggy; Delalande, Jean-Marie; Burns, Alan J.; Cenedese, Angelo; Sebire, Neil J.; Turmaine, Mark; Guest, Brogan N.; Alcorn, John F.; Atala, Anthony; Birchall, Martin A.; Elliott, Martin J.; Eaton, Simon; Pierro, Agostino; Gilbert, Thomas W.; De Coppi, Paolo

    2013-01-01

    Tissue engineering of autologous lung tissue aims to become a therapeutic alternative to transplantation. Efforts published so far in creating scaffolds have used harsh decellularization techniques that damage the extracellular matrix (ECM), deplete its components and take up to 5 weeks to perform. The aim of this study was to create a lung natural acellular scaffold using a method that will reduce the time of production and better preserve scaffold architecture and ECM components. Decellularization of rat lungs via the intratracheal route removed most of the nuclear material when compared to the other entry points. An intermittent inflation approach that mimics lung respiration yielded an acellular scaffold in a shorter time with an improved preservation of pulmonary micro-architecture. Electron microscopy demonstrated the maintenance of an intact alveolar network, with no evidence of collapse or tearing. Pulsatile dye injection via the vasculature indicated an intact capillary network in the scaffold. Morphometry analysis demonstrated a significant increase in alveolar fractional volume, with alveolar size analysis confirming that alveolar dimensions were maintained. Biomechanical testing of the scaffolds indicated an increase in resistance and elastance when compared to fresh lungs. Staining and quantification for ECM components showed a presence of collagen, elastin, GAG and laminin. The intratracheal intermittent decellularization methodology could be translated to sheep lungs, demonstrating a preservation of ECM components, alveolar and vascular architecture. Decellularization treatment and methodology preserves lung architecture and ECM whilst reducing the production time to 3 h. Cell seeding and in vivo experiments are necessary to proceed towards clinical translation. PMID:23727263

  7. The "love-hate" relationship between osteoclasts and bone matrix.

    PubMed

    Rucci, Nadia; Teti, Anna

    2016-01-01

    Osteoclasts are unique cells that destroy the mineralized matrix of the skeleton. There is a "love-hate" relationship between the osteoclasts and the bone matrix, whereby the osteoclast is stimulated by the contact with the matrix but, at the same time, it disrupts the matrix, which, in turn, counteracts this disruption by some of its components. The balance between these concerted events brings about bone resorption to be controlled and to contribute to bone tissue integrity and skeletal health. The matrix components released by osteoclasts are also involved in the local regulation of other bone cells and in the systemic control of organismal homeostasis. Disruption of this regulatory loop causes bone diseases, which may end up with either reduced or increased bone mass, often associated with poor bone quality. Expanding the knowledge on osteoclast-to-matrix interaction could help to counteract these diseases and improve the human bone health. In this article, we will present evidence of the physical, molecular and regulatory relationships between the osteoclasts and the mineralized matrix, discussing the underlying mechanisms as well as their pathologic alterations and potential targeting.

  8. A strategy to quantitate global phosphorylation of bone matrix proteins.

    PubMed

    Sroga, Grażyna E; Vashishth, Deepak

    2016-04-15

    Current studies of protein phosphorylation focus primarily on the importance of specific phosphoproteins and their landscapes of phosphorylation in the regulation of different cellular functions. However, global changes in phosphorylation of extracellular matrix phosphoproteins measured "in bulk" are equally important. For example, correct global phosphorylation of different bone matrix proteins is critical to healthy tissue biomineralization. To study changes of bone matrix global phosphorylation, we developed a strategy that combines a procedure for in vitro phosphorylation/dephosphorylation of fully mineralized bone in addition to quantitation of the global phosphorylation levels of bone matrix proteins. For the first time, we show that it is possible to enzymatically phosphorylate/dephosphorylate fully mineralized bone originating from either cadaveric human donors or laboratory animals (mice). Using our strategy, we detected the difference in the global phosphorylation levels of matrix proteins isolated from wild-type and osteopontin knockout mice. We also observed that the global phosphorylation levels of matrix proteins isolated from human cortical bone were lower than those isolated from trabecular bone. The developed strategy has the potential to open new avenues for studies on the global phosphorylation of bone matrix proteins and their role in biomineralization as well for other tissues/cells and protein-based materials.

  9. Endochondral Ossification for Enhancing Bone Regeneration: Converging Native Extracellular Matrix Biomaterials and Developmental Engineering In Vivo

    PubMed Central

    Dennis, S. Connor; Berkland, Cory J.; Bonewald, Lynda F.

    2015-01-01

    Autologous bone grafting (ABG) remains entrenched as the gold standard of treatment in bone regenerative surgery. Consequently, many marginally successful bone tissue engineering strategies have focused on mimicking portions of ABG's “ideal” osteoconductive, osteoinductive, and osteogenic composition resembling the late reparative stage extracellular matrix (ECM) in bone fracture repair, also known as the “hard” or “bony” callus. An alternative, less common approach that has emerged in the last decade harnesses endochondral (EC) ossification through developmental engineering principles, which acknowledges that the molecular and cellular mechanisms involved in developmental skeletogenesis, specifically EC ossification, are closely paralleled during native bone healing. EC ossification naturally occurs during the majority of bone fractures and, thus, can potentially be utilized to enhance bone regeneration for nearly any orthopedic indication, especially in avascular critical-sized defects where hypoxic conditions favor initial chondrogenesis instead of direct intramembranous ossification. The body's native EC ossification response, however, is not capable of regenerating critical-sized defects without intervention. We propose that an underexplored potential exists to regenerate bone through the native EC ossification response by utilizing strategies which mimic the initial inflammatory or fibrocartilaginous ECM (i.e., “pro-” or “soft” callus) observed in the early reparative stage of bone fracture repair. To date, the majority of strategies utilizing this approach rely on clinically burdensome in vitro cell expansion protocols. This review will focus on the confluence of two evolving areas, (1) native ECM biomaterials and (2) developmental engineering, which will attempt to overcome the technical, business, and regulatory challenges that persist in the area of bone regeneration. Significant attention will be given to native “raw” materials

  10. Adynamic Bone Decreases Bone Toughness During Aging by Affecting Mineral and Matrix.

    PubMed

    Ng, Adeline H; Omelon, Sidney; Variola, Fabio; Allo, Bedilu; Willett, Thomas L; Alman, Benjamin A; Grynpas, Marc D

    2016-02-01

    Adynamic bone is the most frequent type of bone lesion in patients with chronic kidney disease; long-term use of antiresorptive therapy may also lead to the adynamic bone condition. The hallmark of adynamic bone is a loss of bone turnover, and a major clinical concern of adynamic bone is diminished bone quality and an increase in fracture risk. Our current study aims to investigate how bone quality changes with age in our previously established mouse model of adynamic bone. Young and old mice (4 months old and 16 months old, respectively) were used in this study. Col2.3Δtk (DTK) mice were treated with ganciclovir and pamidronate to create the adynamic bone condition. Bone quality was evaluated using established techniques including bone histomorphometry, microcomputed tomography, quantitative backscattered electron imaging, and biomechanical testing. Changes in mineral and matrix properties were examined by powder X-ray diffraction and Raman spectroscopy. Aging controls had a natural decline in bone formation and resorption with a corresponding deterioration in trabecular bone structure. Bone turnover was severely blunted at all ages in adynamic animals, which preserved trabecular bone loss normally associated with aging. However, the preservation of trabecular bone mass and structure in old adynamic mice did not rescue deterioration of bone mechanical properties. There was also a decrease in cortical bone toughness in old adynamic mice that was accompanied by a more mature collagen matrix and longer bone crystals. Little is known about the effects of metabolic bone disease on bone fracture resistance. We observed an age-related decrease in bone toughness that was worsened by the adynamic condition, and this decrease may be due to material level changes at the tissue level. Our mouse model may be useful in the investigation of the mechanisms involved in fractures occurring in elderly patients on antiresorptive therapy who have very low bone turnover. PMID:26332924

  11. Bone matrix hypermineralization in prolyl-3 hydroxylase 1 deficient mice.

    PubMed

    Fratzl-Zelman, Nadja; Bächinger, Hans-Peter; Vranka, Janice A; Roschger, Paul; Klaushofer, Klaus; Rauch, Frank

    2016-04-01

    Lack of prolyl 3-hydroxylase 1 (P3H1) due to mutations in P3H1 results in severe forms of recessive osteogenesis imperfecta. In the present study, we investigated the bone tissue characteristics of P3H1 null mice. Histomorphometric analyses of cancellous bone in the proximal tibia and lumbar vertebra in 1-month and 3-month old mice demonstrated that P3H1 deficient mice had low trabecular bone volume and low mineral apposition rate, but normal osteoid maturation time and normal osteoblast and osteoclast surfaces. Quantitative backscattered electron imaging revealed that the bone mineralization density distribution was shifted towards higher values, indicating hypermineralization of bone matrix. It thus appears that P3H1 deficiency leads to decreased deposition of extracellular matrix by osteoblasts and increased incorporation of mineral into the matrix. PMID:26808442

  12. Recent advances in acellular regenerative tissue scaffolds.

    PubMed

    Protzman, Nicole M; Brigido, Stephen A

    2015-01-01

    The management of chronic wounds is a considerable challenge for foot and ankle surgeons. The well-established tenets of adequate vascular supply, debridement with eradication of infection, and offloading must be employed in the management of all extremity wounds. Regenerative scaffolds are a viable means of reestablishing a favorable wound environment. The matrix facilitates cell migration, chemoattraction, angiogenesis, wound bed granulation, and expedited wound closure. Although studies have demonstrated success with acellular matrices, a multimodal approach should always be employed to improve healing success. Negative pressure wound therapy, compression, offloading, and antibiotics are advocated to improve outcomes. Acellular graft selection requires a multifactorial analysis, taking into consideration the specific patient and wound characteristics as well as the differences between acellular matrices. Patient age, comorbidities, activity level, and ability to comply with protocol as well as wound etiology, duration, depth, surface area, exudate, bacterial burden, location, vascular status, ischemic status, and presentation are all critical components. To effectively choose a matrix, the clinician must have a comprehensive understanding of the products available and the data validating their use. The mechanisms by which the acellular matrix accelerates wound healing and increases the likelihood of wound healing continue to be investigated. However, it is clear that these acellular biologic tissue scaffolds are incorporating into the host tissue, with resultant revascularization and cellular repopulation. Moving forward, additional investigations examining the effectiveness of acellular biologic tissue scaffolds to improve healing in complex, nondiabetic wounds are warranted.

  13. Bone Induction by Demineralized Dentin Matrix in Nude Mouse Muscles

    PubMed Central

    Kim, Kyung-Wook

    2014-01-01

    Purpose: This study examined the osteoinductive activity of demineralized human dentin matrix for nude mice. Methods: Twenty healthy nude mice weighing about 15 to 20 g were used for study. Demineralized human dentin matrix was prepared and implanted into the dorsal portion of nude mice (subcutaneous), which were sacrificed at two, four, and eight weeks after demineralized dentin matrix grafting and evaluated histologically by H&E and Masson trichrome staining. The specimens were also evaluated histomorphometrically. Results: The demineralized dentin matrix induced bone and cartilage formation independently in soft tissues. Histological examination showed bone-forming cells such as osteoblasts and fibroblasts at two, four, and eight weeks. Conclusion: These results suggest that demineralized human dentin matrix has osteoinductive ability, and is a good alternative to autogenous bone graft materials. PMID:27489810

  14. Complication prevalence following use of tutoplast-derived human acellular dermal matrix in prosthetic breast reconstruction: a retrospective review of 203 patients.

    PubMed

    Rundell, V L M; Beck, R T; Wang, C E; Gutowski, K A; Sisco, M; Fenner, G; Howard, M A

    2014-10-01

    Use of human acellular dermal matrix (ADM) during prosthetic breast reconstruction has increased. Several ADM products are available produced by differing manufacturing techniques. It is not known if outcomes vary with different products. This study reports the complication prevalence following use of a tutoplast-derived ADM (T-ADM) in prosthetic breast reconstruction. We performed a retrospective chart review of 203 patients (mean follow-up times 12.2 months) who underwent mastectomy and immediate prosthetic breast reconstruction utilizing T-ADM, recording demographic data, surgical indications and complication (infection, seroma, hematoma, wound healing exceeding three weeks and reconstruction failure). During a four-year period, 348 breast reconstructions were performed Complications occurred in 16.4% of reconstructed breasts. Infection occurred in 6.6% of breast reconstructions (3.7% - major infection, requiring intravenous antibiotics and 2.9% minor infection, requiring oral antibiotics only). Seromas occurred in 3.4% and reconstruction failure occurred in 0.6% of breast reconstructions. Analysis suggested that complication prevalence was significantly higher in patients with a BMI >30 (p = 0.03). The complication profile following T-ADM use is this series is comparable to that reported for with other ADM products. T-ADM appears to be a safe and acceptable option for use in ADM-assisted breast reconstruction. PMID:24917371

  15. Comparison of Achilles tendon repair techniques in a sheep model using a cross-linked acellular porcine dermal patch and platelet-rich plasma fibrin matrix for augmentation.

    PubMed

    Sarrafian, Tiffany L; Wang, Hali; Hackett, Eileen S; Yao, Jian Q; Shih, Mei-Shu; Ramsay, Heather L; Turner, A Simon

    2010-01-01

    The primary goal of this study was to evaluate a cross-linked acellular porcine dermal patch (APD), as well as platelet-rich plasma fibrin matrix (PRPFM), for repair of acute Achilles tendon rupture in a sheep model. The 2 surgically transected tendon ends were reapproximated in groups 1 and 2, whereas a gap was left between the tendon ends in group 3. APD was used to reinforce the repair in group 2, and autologous PRPFM was used to fill the gap, which was also reinforced with APD, in group 3. All sheep were humanely euthanized at 24 weeks after the repair, and biomechanical and histological testing were performed. Tensile strength testing showed a statistically significant difference in elongation between the operated limb and the unoperated contralateral limb in groups 1 and 3, but not in group 2. All operated tendons appeared healed with no apparent fibrosis under light and polarized microscopy. In group 1, all surgical separation sites were identifiable, and healing occurred via increasing tendon thickness. In group 2, healing occurred with new tendon fibers across the separation, without increasing tendon thickness in 2 out of 6 animals. Group 3 showed complete bridging of the gap, with no change in tendon thickness in 2 out of 6 animals. In groups 2 and 3, peripheral integration of the APD to tendon fibers was observed. These findings support the use of APD, alone or with PRPFM, to augment Achilles tendon repair in a sheep model.

  16. A porcine-derived acellular dermal scaffold that supports soft tissue regeneration: removal of terminal galactose-alpha-(1,3)-galactose and retention of matrix structure.

    PubMed

    Xu, Hui; Wan, Hua; Zuo, Wenqi; Sun, Wendell; Owens, Rick T; Harper, John R; Ayares, David L; McQuillan, David J

    2009-07-01

    Sub-optimal clinical outcomes after implantation of animal-derived tissue matrices may be attributed to the nature of the processing of the material or to an immune response elicited in response to xenogeneic epitopes. The ability to produce a porcine-derived graft that retains the structural integrity of the extracellular matrix and minimizes potential antigenic response to galactose-alpha-(1,3)-galactose terminal disaccharide (alpha-Gal) may allow the scaffold to support regeneration of native tissue. Dermal tissue from wild-type (WT-porcine-derived acellular dermal matrix [PADM]) or Gal-deficient (Gal(-/-) PADM) pigs was processed to remove cells and DNA while preserving the structural integrity of the extracellular matrix. In addition, the WT tissue was subjected to an enzymatic treatment to minimize the presence of alpha-Gal (Gal-reduced PADM). Extracellular matrix composition and integrity was assessed by histological, immunohistochemical (IHC), and ultrastructural analysis. In vivo performance was evaluated by implantation into the abdominal wall of Old World primates in an exisional repair model. Anti-alpha-Gal activity in the serum of monkeys implanted subcutaneously was assessed by ELISA. Minimal modification to the extracellular matrix was assessed by evaluation of intact structure as demonstrated by staining patterns for type I and type VII collagens, laminin, and fibronectin similar to native porcine skin tissues. Explants from the abdominal wall showed evidence of remodeling, notably fibroblast cell repopulation and revascularization, as early as 1 month. Serum ELISA revealed an initial anti-alpha-Gal induction that decreased to baseline levels over time in the primates implanted with WT-PADM, whereas no or minimal anti-Gal activity was detected in the primates implanted with Gal(-/-) PADM or Gal-reduced PADM. The combination of a nondamaging process, successful removal of cells, and reduction of xenogeneic alpha-Gal antigens from the porcine dermal

  17. Heterotopic new bone formation causes resorption of the inductive bone matrix

    SciTech Connect

    Nilsson, O.S.; Persson, P.E.; Ekelund, A. )

    1990-08-01

    The bone matrix of growing rats was labeled by multiple injections of 3H-proline, and demineralized bone matrix (DBM) was prepared. The DBM was allotransplanted heterotopically into growing rats. New bone formation was induced in and around the implants. The new bone formation was accompanied by a decrease in the content of 3H; 20 and 30 days after implantation, 72% and 46%, respectively, of the activity remained in the implants. Daily injections of indomethacin (2 mg/kg) inhibited calcium uptake by about 20% at 20 and 30 days and inhibited the release of 3H from the DBM to a similar degree. Heterotopic bone induction by DBM is accompanied by matrix resorption, and inhibition of the new bone formation decreases the resorption of DBM.

  18. Enhanced Ex Vivo Expansion of Human Hematopoietic Progenitors on Native and Spin Coated Acellular Matrices Prepared from Bone Marrow Stromal Cells

    PubMed Central

    Wasnik, Samiksha; Kantipudi, Suma; Kirkland, Mark A.; Pande, Gopal

    2016-01-01

    The extracellular microenvironment in bone marrow (BM) is known to regulate the growth and differentiation of hematopoietic stem and progenitor cells (HSPC). We have developed cell-free matrices from a BM stromal cell line (HS-5), which can be used as substrates either in native form or as tissue engineered coatings, for the enhanced ex vivo expansion of umbilical cord blood (UCB) derived HSPC. The physicochemical properties (surface roughness, thickness, and uniformity) of native and spin coated acellular matrices (ACM) were studied using scanning and atomic force microscopy (SEM and AFM). Lineage-specific expansion of HSPC, grown on these substrates, was evaluated by immunophenotypic (flow cytometry) and functional (colony forming) assays. Our results show that the most efficient expansion of lineage-specific HSPC occurred on spin coated ACM. Our method provides an improved protocol for ex vivo HSPC expansion and it offers a system to study the in vivo roles of specific molecules in the hematopoietic niche that influence HSPC expansion. PMID:26981135

  19. Effect of Extracellular Matrix Membrane on Bone Formation in a Rabbit Tibial Defect Model

    PubMed Central

    Kim, Sungtae; Kim, Se Won; Lee, Jong Ho

    2016-01-01

    Absorbable extracellular matrix (ECM) membrane has recently been used as a barrier membrane (BM) in guided tissue regeneration (GTR) and guided bone regeneration (GBR). Absorbable BMs are mostly based on collagen, which is more biocompatible than synthetic materials. However, implanted absorbable BMs can be rapidly degraded by enzymes in vivo. In a previous study, to delay degradation time, collagen fibers were treated with cross-linking agents. These compounds prevented the enzymatic degradation of BMs. However, cross-linked BMs can exhibit delayed tissue integration. In addition, the remaining cross-linker could induce inflammation. Here, we attempted to overcome these problems using a natural ECM membrane. The membrane consisted of freshly harvested porcine pericardium that was stripped from cells and immunoreagents by a cleaning process. Acellular porcine pericardium (APP) showed a bilayer structure with a smooth upper surface and a significantly coarser bottom layer. APP is an ECM with a thin layer (0.18–0.35 mm) but with excellent mechanical properties. Tensile strength of APP was 14.15 ± 2.24 MPa. In in vivo experiments, APP was transplanted into rabbit tibia. The biocompatible material was retained for up to 3 months without the need for cross-linking. Therefore, we conclude that APP could support osteogenesis as a BM for up to 3 months. PMID:27047963

  20. A nanomedicine approach to effectively inhibit contracture during bladder acellular matrix allograft-induced bladder regeneration by sustained delivery of vascular endothelial growth factor.

    PubMed

    Xiong, Qianwei; Lin, Houwei; Hua, Xiaolin; Liu, Li; Sun, Ping; Zhao, Zhen; Shen, Xiaowei; Cui, Daxiang; Xu, Maosheng; Chen, Fang; Geng, Hongquan

    2015-01-01

    Macroscopic evidence of contracture has been identified as a major issue during the regeneration process. We hypothesize that lack of angiogenesis is the primary cause of contracture and explore a nanomedicine approach to achieve sustained release of vascular endothelial growth factor (VEGF) to stimulate angiogenesis. We evaluate the efficacy of poly(lactic-co-glycolic acid) (PLGA) nanoparticles (NPs) for long-term (3 months) sustained release of VEGF in bladder acellular matrix allografts (BAMA) in a swine model. We anticipate that the sustained release of VEGF could stimulate angiogenesis along the regeneration process and thereby inhibit contracture. Bladder was replaced with BAMA (5×5 cm), modified with PLGA NPs encapsulated with VEGF in a pig model. The time points chosen for sampling were 1, 2, 4, and 12 weeks. The regenerated areas were then measured to obtain the contracture rate, and the extent of revascularization was calculated using histological and morphological features. In the control group of animals, the bladder was replaced with only BAMA. The in vivo release of VEGF was evident for ∼3 months, achieving the goal of long-acting sustained release, and successfully promoted the regeneration of blood vessels and smooth muscle fibers. In addition, less collagen deposition was observed in the experimental group compared with control. Most importantly, the inhibition of contracture was highly significant, and the ultimate contracture rate decreased by ∼57% in the experimental group compared with control. In isolated strips analysis, there were no significant differences between BAMA-regenerated (either VEGF added or not) and autogenous bladder. BAMA modified with VEGF-loaded PLGA-NPs can sustainably release VEGF in vivo (>3 months) to stimulate angiogenesis leading to the inhibition of contracture. This is the first study to report a viable nanomedicine-based strategy to overcome contracture during bladder regeneration induced by BAMA. Furthermore

  1. Acellular dermal matrix seeded with autologous fibroblasts improves wound breaking strength in a rodent soft tissue damage model in neoadjuvant settings.

    PubMed

    Roessner, Eric Dominic; Thier, Steffen; Hohenberger, Peter; Schwarz, Markus; Pott, Peter; Dinter, Dietmar; Smith, Mark

    2011-01-01

    Soft tissue defects following resectional surgery or trauma often result in deadspaces and require free or pedicled flaps. A programmed formation of filling tissue with enhanced biomechanical properties could be helpful. This study examined the effects on wound healing of acellular dermal matrix (ADM) seeded with autologous fibroblasts in a standardized rodent model. As pre- or postoperative radiotherapy is standard in many treatments of malignancies, we also investigated the effects of additional radiotherapy. Fischer rats were randomised and received a standardized unilateral soft tissue defect at the buttock. The defect was filled with ADM+fibroblasts or ADM alone. Controls received no filling. Either no radiation, adjuvant (postoperative) or neoadjuvant (preoperative) radiation was applied to the defect site. Six weeks later the defect volume was measured by MR-tomography. Wound breaking strength was examined by tensiometry according to German Industrial Standards. Filling of the defect side was significantly larger in ADM and ADM+fibroblast treated groups compared to the control group in all settings. Wound breaking strength in the unimodal setting was significantly improved in the ADM+fibroblasts group compared to the ADM group. In the neoadjuvant setting there was no significant difference between control and ADM group. However, the ADM+fibroblasts groups showed a significantly increased wound breaking strength compared to the control and the ADM-alone group. Seeded or unseeded ADM is able to fill deadspace in this rodent model in all settings. Implanting non-irradiated, vital, proliferating autologous fibroblasts on ADM results in significantly increased wound breaking strength.

  2. A Nanomedicine Approach to Effectively Inhibit Contracture During Bladder Acellular Matrix Allograft-Induced Bladder Regeneration by Sustained Delivery of Vascular Endothelial Growth Factor

    PubMed Central

    Xiong, Qianwei; Lin, Houwei; Hua, Xiaolin; Liu, Li; Sun, Ping; Zhao, Zhen; Shen, Xiaowei; Cui, Daxiang; Xu, Maosheng

    2015-01-01

    Macroscopic evidence of contracture has been identified as a major issue during the regeneration process. We hypothesize that lack of angiogenesis is the primary cause of contracture and explore a nanomedicine approach to achieve sustained release of vascular endothelial growth factor (VEGF) to stimulate angiogenesis. We evaluate the efficacy of poly(lactic-co-glycolic acid) (PLGA) nanoparticles (NPs) for long-term (3 months) sustained release of VEGF in bladder acellular matrix allografts (BAMA) in a swine model. We anticipate that the sustained release of VEGF could stimulate angiogenesis along the regeneration process and thereby inhibit contracture. Bladder was replaced with BAMA (5×5 cm), modified with PLGA NPs encapsulated with VEGF in a pig model. The time points chosen for sampling were 1, 2, 4, and 12 weeks. The regenerated areas were then measured to obtain the contracture rate, and the extent of revascularization was calculated using histological and morphological features. In the control group of animals, the bladder was replaced with only BAMA. The in vivo release of VEGF was evident for ∼3 months, achieving the goal of long-acting sustained release, and successfully promoted the regeneration of blood vessels and smooth muscle fibers. In addition, less collagen deposition was observed in the experimental group compared with control. Most importantly, the inhibition of contracture was highly significant, and the ultimate contracture rate decreased by ∼57% in the experimental group compared with control. In isolated strips analysis, there were no significant differences between BAMA-regenerated (either VEGF added or not) and autogenous bladder. BAMA modified with VEGF-loaded PLGA-NPs can sustainably release VEGF in vivo (>3 months) to stimulate angiogenesis leading to the inhibition of contracture. This is the first study to report a viable nanomedicine-based strategy to overcome contracture during bladder regeneration induced by BAMA. Furthermore

  3. A Prospective Study Assessing Complication Rates and Patient-Reported Outcomes in Breast Reconstructions Using a Novel, Deep Dermal Human Acellular Dermal Matrix

    PubMed Central

    Vu, Michael M.; De Oliveira, Gildasio S.; Mayer, Kristen E.; Blough, Jordan T.

    2015-01-01

    Abstract Background: The value proposition of an acellular dermal matrix (ADM) taken from the deep dermis is that the allograft may be more porous, allowing for enhanced integration and revascularization. In turn, this characteristic may attenuate complications related to foreign body reactions, seromas, and infection. However, this is juxtaposed against the potential loss of allograft structural integrity, with subsequent risk of malposition and extrusion. Despite the active use of novel, deep dermal ADMs, the clinical outcomes of this new technology has not been well studied. Methods: This is a prospective study to evaluate surgical and patient-reported outcomes using a deep dermal ADM, FlexHD Pliable. Surgical outcomes and BREAST-Q patient-reported outcomes were evaluated postoperatively at 2- and 6-month time points. Results: Seventy-two breasts (41 patients) underwent reconstruction. Complication rate was 12.5%, including 2 hematomas and 7 flap necroses. One case of flap necrosis led to reconstructive failure. Notably, there were no cases of infection, seroma, or implant extrusion or malposition. Average BREAST-Q scores were satisfaction with outcome (70.13 ± 23.87), satisfaction with breasts (58.53 ± 20.00), psychosocial well being (67.97 ± 20.93), sexual well being (54.11 ± 27.72), and physical well being (70.45 ± 15.44). Two-month postoperative BREAST-Q scores decreased compared with baseline and returned to baseline by 6 months. Postoperative radiation therapy had a negative effect on satisfaction with breasts (P = 0.004) and sexual well being (P = 0.006). Conclusions: Deep dermal ADM is a novel modification of traditional allograft technology. Use of the deep dermal ADM yielded acceptably low complication rates and satisfactory patient-reported outcomes. PMID:26894010

  4. Experimental assessment of the neo-vascularisation of acellular dermal matrix in the wound bed pretreated with mesenchymal stem cell under subatmospheric pressure.

    PubMed

    Sahin, Ismail; Ozturk, Sinan; Deveci, Mustafa; Ural, Ali Ugur; Onguru, Onder; Isik, Selcuk

    2014-01-01

    Neo-vascularisation of the acellular dermal matrix (ADM) is an essential procedure if a full-thickness wound is closed with ADM and skin is grafted over the ADM. In this study, we aimed to improve the neo-vascularisation of ADM by combining the effects of negative pressure wound therapy (NPWT) and mesenchymal stem cells (MSCs) on angiogenesis. In this study, 28 female Sprague-Dawley rats were used and divided into four groups. Full-thickness dorsal skin defects were created in 2 × 2 cm dimensions. The wounds were treated with only the ADM in group 1, the ADM and NPWT in group 2, the ADM and MSCs in group 3 and the ADM, NPWT and MSCs in group 4. By the ninth day of surgery, the excisional biopsy samples were histologically examined to identify the rates of ADM adherence to the recipient bed; the newly formed blood vessels which penetrate the ADM vertically and vascularisation were evaluated by immunohistochemical staining. The graft adherence rates were higher in group 4 than in the other groups statistically, p = 0.003. The numbers of cluster of differentiation 31 (CD31)-stained newly formed microvessels were higher in group 4 than in the other groups statistically, p < 0.05. All subjects in group 4 had the vertical vessels in normal calibration with open lumen vessels which penetrate the ADM. These findings suggest that MSC transplantation induces angiogenesis more efficiently than NPWT. The combination of the NPWT with MSC in this study has shown a synergistic effect on angiogenesis and has affected the neo-vascularisation of the ADM significantly.

  5. A Comparison of Acellular Dermal Matrix Allograft and Periosteal Pedicle Graft Covered by Coronally Advanced Flap in the Treatment of Gingival Recession: 1-Year Follow-Up Study.

    PubMed

    Godavarthi, Lalasa; Murthy, K Raja; Pavankumar, Sandhya

    2016-01-01

    The objective of this study was to evaluate and compare the clinical efficacy of periosteal pedicle graft (PPG) and acellular dermal matrix allograft (ADMA) in conjunction with coronally advanced flap (CAF) in the treatment of gingival recession during a 1-year follow-up. A sample of 14 patients, each with two similar Miller Class I or II gingival recession (28 recession sites), was selected. Each recession site was randomly assigned to the experimental site (PPG + CAF) or the control site (ADMG + CAF). The clinical parameters recorded at baseline and 12 months postoperatively were probing pocket depth, width of keratinized gingiva, and clinical attachment level, whereas full-mouth and site-specific plaque and gingival index and vertical recession depth and width were recorded at baseline and at 1, 3, 6, 9, and 12 months. Analysis was performed to determine if treatment differences were present. The mean recession depth in experimental sites decreased from 2.89 ± 0.40 mm at baseline to 0.25 ± 0.50 mm at 12 months, corresponding to a mean root coverage of 92.79% ± 14.25%. In control sites, recession shrank from 2.93 ± 0.55 mm at baseline to 0.32 ± 0.46 mm at 12 months follow-up, demonstrating a mean root coverage of 89.79% ± 14.73%. Compared to the use of ADMA, the PPG technique uses similar incision design and flap management at the graft site, is equivalent in technique sensitivity, and has a perceived improvement in esthetic outcome. PMID:27333020

  6. [Vertebral trabecular bone in various age groups and in osteoporosis-- morphometry and bone matrix biochemistry].

    PubMed

    Diebold, J; Bätge, B; Stein, H; Müller, P K; Löhrs, U

    1990-01-01

    Vertebral trabecular bone was analysed by morphometry and bone matrix biochemistry. Trabecular bone volume (TBV) and mean trabecular plate thickness (MTPT) decreased with age. TBV was significantly correlated with MTPT and mean trabecular plate density (MTPD). The individual structure of trabecular bone could be described by both MTPT and MTPD together, but changes of these parameters, that were pathognomonic for osteopenia, were not found. By measuring TBV 3 cases of severe osteopenia were identified (TBV less than 2s of controls); 2 of them showed matrix abnormalities so far not described. In one case (a 67 year old woman without risk factors for osteoporosis) an abnormal high content of type III collagen was found, in the other case (a 44 year old woman with acromegaly) bone matrix analysis atypically revealed a significant fraction of type II collagen. Further studies will be needed to assess the pathogenetic or diagnostic importance of these new findings.

  7. "High-grade" central acellular carcinoma and matrix-producing carcinoma of the breast: correlation between ultrasonographic findings and pathological features.

    PubMed

    Yamaguchi, Rin; Tanaka, Maki; Mizushima, Yasuko; Hirai, Yoshitake; Yamaguchi, Miki; Terasaki, Hiroshi; Yokoyama, Toshiro; Tsuchiya, Shin-ichi; Nakashima, Osamu; Yano, Hirohisa

    2011-09-01

    High-grade carcinoma with a large central acellular zone (central acellular carcinoma, CAC) and matrixproducing carcinoma (MPC) are aggressive tumors that both have a central myxomatous acellular zone. Their characteristic morphology may be useful in diagnostic imaging. Ultrasonographic findings based on the Breast Imaging Recording and Data System (BI-RADS) and detailed histological features were evaluated in 11 cases of CAC and 2 cases of MPC to characterize their features. Safranin-O staining was undertaken for the evaluation of central acellular zones in these tumors. Overall, ultrasonography demonstrated heterogeneous hyperechoic lesions in the center of the hypoechoic mass. Posterior echo enhancement was observed in all but 1 case. One case was classified as malignant and the others as "borderline." Histologically, cancer tissue was located in the periphery of the tumor with a ring-like structure and fewer cellular central areas comprising hyaline cartilage myxoid material such as those stained by safranin-O. The present study showed that the pathological findings of CACs and MPCs accurately reflect the ultrasonographic findings. Tumors that showed hyperechoic areas in the center of the hypoechoic mass, with posterior echo enhancement indicating acellular zones composed by myxochondroid material, and that were also relatively round on ultrasonography may be benign, but evaluation is required to exclude CAC and MPC.

  8. Spine Fusion Using Cell Matrix Composites Enriched in Bone Marrow-Derived Cells

    PubMed Central

    Nitto, Hironori; Matsukura, Yoichi; Boehm, Cynthia; Valdevit, Antonio; Kambic, Helen; Davros, William; Powell, Kimerly; Easley, Kirk

    2005-01-01

    Bone marrow-derived cells including osteoblastic progenitors can be concentrated rapidly from bone marrow aspirates using the surface of selected implantable matrices for selective cell attachment. Concentration of cells in this way to produce an enriched cellular composite graft improves graft efficacy. The current study was designed to test the hypothesis that the biologic milieu of a bone marrow clot will significantly improve the efficacy of such a graft. An established posterior spinal fusion model and cancellous bone matrix was used to compare an enriched cellular composite bone graft alone, bone matrix plus bone marrow clot, and an enriched bone matrix composite graft plus bone marrow clot. Union score, quantitative computed tomography, and mechanical testing were used to define outcome. The union score for the enriched bone matrix plus bone marrow clot composite was superior to the enriched bone matrix alone and the bone matrix plus bone marrow clot. The enriched bone matrix plus bone marrow clot composite also was superior to the enriched bone matrix alone in fusion volume and in fusion area. These data confirm that the addition of a bone marrow clot to an enriched cell-matrix composite graft results in significant improvement in graft performance. Enriched composite grafts prepared using this strategy provide a rapid, simple, safe, and inexpensive method for intraoperative concentration and delivery of bone marrow-derived cells and connective tissue progenitors that may improve the outcome of bone grafting. PMID:12567137

  9. Tensile behavior of cortical bone: dependence of organic matrix material properties on bone mineral content.

    PubMed

    Kotha, S P; Guzelsu, N

    2007-01-01

    A porous composite model is developed to analyze the tensile mechanical properties of cortical bone. The effects of microporosity (volksman's canals, osteocyte lacunae) on the mechanical properties of bone tissue are taken into account. A simple shear lag theory, wherein tensile loads are transferred between overlapped mineral platelets by shearing of the organic matrix, is used to model the reinforcement provided by mineral platelets. It is assumed that the organic matrix is elastic in tension and elastic-perfectly plastic in shear until it fails. When organic matrix shear stresses at the ends of mineral platelets reach their yield values, the stress-strain curve of bone tissue starts to deviate from linear behavior. This is referred as the microscopic yield point. At the point where the stress-strain behavior of bone shows a sharp curvature, the organic phase reaches its shear yield stress value over the entire platelet. This is referred as the macroscopic yield point. It is assumed that after macroscopic yield, mineral platelets cannot contribute to the load bearing capacity of bone and that the mechanical behavior of cortical bone tissue is determined by the organic phase only. Bone fails when the principal stress of the organic matrix is reached. By assuming that mechanical properties of the organic matrix are dependent on bone mineral content below the macroscopic yield point, the model is used to predict the entire tensile mechanical behavior of cortical bone for different mineral contents. It is found that decreased shear yield stresses and organic matrix elastic moduli are required to explain the mechanical behavior of bones with lowered mineral contents. Under these conditions, the predicted values (elastic modulus, 0.002 yield stress and strain, and ultimate stress and strain) are within 15% of experimental data.

  10. Tensile behavior of cortical bone: dependence of organic matrix material properties on bone mineral content.

    PubMed

    Kotha, S P; Guzelsu, N

    2007-01-01

    A porous composite model is developed to analyze the tensile mechanical properties of cortical bone. The effects of microporosity (volksman's canals, osteocyte lacunae) on the mechanical properties of bone tissue are taken into account. A simple shear lag theory, wherein tensile loads are transferred between overlapped mineral platelets by shearing of the organic matrix, is used to model the reinforcement provided by mineral platelets. It is assumed that the organic matrix is elastic in tension and elastic-perfectly plastic in shear until it fails. When organic matrix shear stresses at the ends of mineral platelets reach their yield values, the stress-strain curve of bone tissue starts to deviate from linear behavior. This is referred as the microscopic yield point. At the point where the stress-strain behavior of bone shows a sharp curvature, the organic phase reaches its shear yield stress value over the entire platelet. This is referred as the macroscopic yield point. It is assumed that after macroscopic yield, mineral platelets cannot contribute to the load bearing capacity of bone and that the mechanical behavior of cortical bone tissue is determined by the organic phase only. Bone fails when the principal stress of the organic matrix is reached. By assuming that mechanical properties of the organic matrix are dependent on bone mineral content below the macroscopic yield point, the model is used to predict the entire tensile mechanical behavior of cortical bone for different mineral contents. It is found that decreased shear yield stresses and organic matrix elastic moduli are required to explain the mechanical behavior of bones with lowered mineral contents. Under these conditions, the predicted values (elastic modulus, 0.002 yield stress and strain, and ultimate stress and strain) are within 15% of experimental data. PMID:16434048

  11. Multifunctional and stable bone mimic proteinaceous matrix for bone tissue engineering.

    PubMed

    Won, Jong-Eun; Yun, Ye-Rang; Jang, Jun-Hyeog; Yang, Sung-Hee; Kim, Joong-Hyun; Chrzanowski, Wojciech; Wall, Ivan B; Knowles, Jonathan C; Kim, Hae-Won

    2015-07-01

    Biomaterial surface design with biomimetic proteins holds great promise for successful regeneration of tissues including bone. Here we report a novel proteinaceous hybrid matrix mimicking bone extracellular matrix that has multifunctional capacity to promote stem cell adhesion and osteogenesis with excellent stability. Osteocalcin-fibronectin fusion protein holding collagen binding domain was networked with fibrillar collagen, featuring bone extracellular matrix mimic, to provide multifunctional and structurally-stable biomatrices. The hybrid protein, integrated homogeneously with collagen fibrillar networks, preserved structural stability over a month. Biological efficacy of the hybrid matrix was proven onto tethered surface of biopolymer porous scaffolds. Mesenchymal stem cells quickly anchored to the hybrid matrix, forming focal adhesions, and substantially conformed to cytoskeletal extensions, benefited from the fibronectin adhesive domains. Cells achieved high proliferative capacity to reach confluence rapidly and switched to a mature and osteogenic phenotype more effectively, resulting in greater osteogenic matrix syntheses and mineralization, driven by the engineered osteocalcin. The hybrid biomimetic matrix significantly improved in vivo bone formation in calvarial defects over 6 weeks. Based on the series of stimulated biological responses in vitro and in vivo the novel hybrid proteinaceous composition will be potentially useful as stem cell interfacing matrices for osteogenesis and bone regeneration.

  12. Editorial Commentary: Reflections From a Mature Arthroscopic Shoulder Surgeon on the History and Current Benefits of Augmentation for the Revision of a Massive Rotator Cuff Tear Using Acellular Human Dermal Matrix Allograft.

    PubMed

    Snyder, Stephen J

    2016-09-01

    Acellular human dermal matrix allografts are now being used to augment and sometimes replace severely damaged rotator cuff tissue. I have been interested in this important aspect of orthopaedics for 15 years and am pleased to have the opportunity to share my personal reflections of some of the highlights in science and the literature that helped get to the point now where we can expect greater than 80% healing even in these difficult cases of revision after massive failed cuff repair. The field of tissue engineering will certainly be a critical part of our rotator cuff surgical future.

  13. Editorial Commentary: Reflections From a Mature Arthroscopic Shoulder Surgeon on the History and Current Benefits of Augmentation for the Revision of a Massive Rotator Cuff Tear Using Acellular Human Dermal Matrix Allograft.

    PubMed

    Snyder, Stephen J

    2016-09-01

    Acellular human dermal matrix allografts are now being used to augment and sometimes replace severely damaged rotator cuff tissue. I have been interested in this important aspect of orthopaedics for 15 years and am pleased to have the opportunity to share my personal reflections of some of the highlights in science and the literature that helped get to the point now where we can expect greater than 80% healing even in these difficult cases of revision after massive failed cuff repair. The field of tissue engineering will certainly be a critical part of our rotator cuff surgical future. PMID:27594327

  14. An injectable acellular matrix scaffold with absorbable permeable nanoparticles improves the therapeutic effects of docetaxel on glioblastoma.

    PubMed

    Xu, He-Lin; Mao, Kai-Li; Lu, Cui-Tao; Fan, Zi-Liang; Yang, Jing-Jing; Xu, Jie; Chen, Pian-Pian; ZhuGe, De-Li; Shen, Bi-Xin; Jin, Bing-Hui; Xiao, Jian; Zhao, Ying-Zheng

    2016-11-01

    Intratumoral drug delivery (IT) is an inherently appealing approach for concentrating toxic chemotherapies at the site of action. However, for most chemotherapies, poor tumor penetration and short retention at the administration site limit their anti-tumor effects. In this work, we describe permeable nanoparticles (NPs) prepared with a novel amphiphilic polymer, RRR-α-tocopheryl succinate-grafted-ε-polylysine conjugate (VES-g-ε-PLL). The nanoparticles (NPs) of VES-g-ε-PLL exhibited an ultra-small hydrodynamic diameter (20.8 nm) and positive zeta potential (20.6 mV), which facilitate strong glioma spheroid penetration ability in vitro. Additionally, the hydrophobic model drug docetaxel (DTX) could be effectively encapsulated in the nanoparticles with 3.99% drug loading and 73.37% encapsulation efficiency. To prolong the retention time of DTX-loaded nanoparticles (DTX-NPs) in the tumor, intact decellularized brain extracellular matrix (dBECM) derived from healthy rats was used as a drug depot to adsorb the ultra-small DTX-NPs. The intact DTX-NPs-adsorbing dBECM scaffold was further homogenized into an injectable DTX-NPs-dBECM suspension for intratumoral administration. The DTX-NPs-dBECM suspension exhibited slower DTX release than naked DTX-NPs without compromising the tumor penetration ability of DTX-NPs. An antitumor study showed that the DTX-NPs-dBECM suspension exhibited more powerful in vitro inhibition of tumor spheroid growth than free DTX solution or DTX-NPs. Due to strong tumor penetration ability and prolonged retention, DTX-NPs-dBECM led to complete suppression of glioma growth in vivo at 28 days after treatment. The therapeutic mechanism was due to enhanced proliferation inhibition and apoptosis of tumor cells and angiogenesis inhibition of glioma after treatment with DTX-NPs-dBECM. Finally, the safety of DTX-NPs-dBECM at the therapeutic dose was demonstrated via pathological HE assay from heart, liver, spleen, lung and kidney tissues. In

  15. Adipose-derived stem-cell-seeded non-cross-linked porcine acellular dermal matrix increases cellular infiltration, vascular infiltration, and mechanical strength of ventral hernia repairs.

    PubMed

    Iyyanki, Tejaswi S; Dunne, Lina W; Zhang, Qixu; Hubenak, Justin; Turza, Kristin C; Butler, Charles E

    2015-02-01

    Adipose-derived stem cells (ASCs) facilitate wound healing by improving cellular and vascular recruitment to the wound site. Therefore, we investigated whether ASCs would augment a clinically relevant bioprosthetic mesh-non-cross-linked porcine acellular dermal matrix (ncl-PADM)-used for ventral hernia repairs in a syngeneic animal model. ASCs were isolated from the subcutaneous adipose tissue of Brown Norway rats, expanded, and labeled with green fluorescent protein. ASCs were seeded (2.5×10(4) cells/cm(2)) onto ncl-PADM for 24 h before surgery. In vitro ASC adhesion to ncl-PADM was assessed at 0.5, 1, and 2 h after seeding, and cell morphology on ncl-PADM was visualized by scanning electron microscopy. Ventral hernia defects (2×4 cm) were created and repaired with ASC-seeded (n=31) and control (n=32) ncl-PADM. Explants were harvested at 1, 2, and 4 weeks after surgery. Explant remodeling outcomes were evaluated using gross evaluation (bowel adhesions, surface area, and grade), histological analysis (hematoxylin and eosin and Masson's trichrome staining), immunohistochemical analysis (von Willebrand factor VIII), fluorescent microscopy, and mechanical strength measurement at the tissue-bioprosthetic mesh interface. Stem cell markers CD29, CD90, CD44, and P4HB were highly expressed in cultured ASCs, whereas endothelial and hematopoietic cell markers, such as CD31, CD90, and CD45 had low expression. Approximately 85% of seeded ASCs adhered to ncl-PADM within 2 h after seeding, which was further confirmed by scanning electron microcopy examination. Gross evaluation of the hernia repairs revealed weak omental adhesion in all groups. Ultimate tensile strength was not significantly different in control and treatment groups. Conversely, elastic modulus was significantly greater at 4 weeks postsurgery in the ASC-seeded group (p<0.001). Cellular infiltration was significantly higher in the ASC-seeded group at all time points (p<0.05). Vascular infiltration was

  16. Adipose-Derived Stem-Cell-Seeded Non-Cross-Linked Porcine Acellular Dermal Matrix Increases Cellular Infiltration, Vascular Infiltration, and Mechanical Strength of Ventral Hernia Repairs

    PubMed Central

    Iyyanki, Tejaswi S.; Dunne, Lina W.; Zhang, Qixu; Hubenak, Justin; Turza, Kristin C.

    2015-01-01

    Adipose-derived stem cells (ASCs) facilitate wound healing by improving cellular and vascular recruitment to the wound site. Therefore, we investigated whether ASCs would augment a clinically relevant bioprosthetic mesh—non-cross-linked porcine acellular dermal matrix (ncl-PADM)—used for ventral hernia repairs in a syngeneic animal model. ASCs were isolated from the subcutaneous adipose tissue of Brown Norway rats, expanded, and labeled with green fluorescent protein. ASCs were seeded (2.5×104 cells/cm2) onto ncl-PADM for 24 h before surgery. In vitro ASC adhesion to ncl-PADM was assessed at 0.5, 1, and 2 h after seeding, and cell morphology on ncl-PADM was visualized by scanning electron microscopy. Ventral hernia defects (2×4 cm) were created and repaired with ASC-seeded (n=31) and control (n=32) ncl-PADM. Explants were harvested at 1, 2, and 4 weeks after surgery. Explant remodeling outcomes were evaluated using gross evaluation (bowel adhesions, surface area, and grade), histological analysis (hematoxylin and eosin and Masson's trichrome staining), immunohistochemical analysis (von Willebrand factor VIII), fluorescent microscopy, and mechanical strength measurement at the tissue-bioprosthetic mesh interface. Stem cell markers CD29, CD90, CD44, and P4HB were highly expressed in cultured ASCs, whereas endothelial and hematopoietic cell markers, such as CD31, CD90, and CD45 had low expression. Approximately 85% of seeded ASCs adhered to ncl-PADM within 2 h after seeding, which was further confirmed by scanning electron microcopy examination. Gross evaluation of the hernia repairs revealed weak omental adhesion in all groups. Ultimate tensile strength was not significantly different in control and treatment groups. Conversely, elastic modulus was significantly greater at 4 weeks postsurgery in the ASC-seeded group (p<0.001). Cellular infiltration was significantly higher in the ASC-seeded group at all time points (p<0.05). Vascular infiltration was

  17. Structural features underlying raloxifene's biophysical interaction with bone matrix.

    PubMed

    Bivi, Nicoletta; Hu, Haitao; Chavali, Balagopalakrishna; Chalmers, Michael J; Reutter, Christopher T; Durst, Gregory L; Riley, Anna; Sato, Masahiko; Allen, Matthew R; Burr, David D; Dodge, Jeffrey A

    2016-02-15

    Raloxifene, a selective estrogen receptor modulator (SERM), reduces fracture risk at least in part by improving the mechanical properties of bone in a cell- and estrogen receptor-independent manner. In this study, we determined that raloxifene directly interacts with the bone tissue. Through the use of multiple and complementary biophysical techniques including nuclear magnetic resonance (NMR) and Fourier transform infrared spectroscopy (FTIR), we show that raloxifene interacts specifically with the organic component or the organic/mineral composite, and not with hydroxyapatite. Structure-activity studies reveal that the basic side chain of raloxifene is an instrumental determinant in the interaction with bone. Thus, truncation of portions of the side chain reduces bone binding and also diminishes the increase in mechanical properties. Our results support a model wherein the piperidine interacts with bone matrix through electrostatic interactions with the piperidine nitrogen and through hydrophobic interactions (van der Waals) with the aliphatic groups in the side chain and the benzothiophene core. Furthermore, in silico prediction of the potential binding sites on the surface of collagen revealed the presence of a groove with sufficient space to accommodate raloxifene analogs. The hydroxyl groups on the benzothiophene nucleus, which are necessary for binding of SERMs to the estrogen receptor, are not required for binding to the bone surface, but mediate a more robust binding of the compound to the bone powder. In conclusion, we report herein a novel property of raloxifene analogs that allows them to interact with the bone tissue through potential contacts with the organic matrix and in particular collagen. PMID:26795112

  18. Structural features underlying raloxifene's biophysical interaction with bone matrix.

    PubMed

    Bivi, Nicoletta; Hu, Haitao; Chavali, Balagopalakrishna; Chalmers, Michael J; Reutter, Christopher T; Durst, Gregory L; Riley, Anna; Sato, Masahiko; Allen, Matthew R; Burr, David D; Dodge, Jeffrey A

    2016-02-15

    Raloxifene, a selective estrogen receptor modulator (SERM), reduces fracture risk at least in part by improving the mechanical properties of bone in a cell- and estrogen receptor-independent manner. In this study, we determined that raloxifene directly interacts with the bone tissue. Through the use of multiple and complementary biophysical techniques including nuclear magnetic resonance (NMR) and Fourier transform infrared spectroscopy (FTIR), we show that raloxifene interacts specifically with the organic component or the organic/mineral composite, and not with hydroxyapatite. Structure-activity studies reveal that the basic side chain of raloxifene is an instrumental determinant in the interaction with bone. Thus, truncation of portions of the side chain reduces bone binding and also diminishes the increase in mechanical properties. Our results support a model wherein the piperidine interacts with bone matrix through electrostatic interactions with the piperidine nitrogen and through hydrophobic interactions (van der Waals) with the aliphatic groups in the side chain and the benzothiophene core. Furthermore, in silico prediction of the potential binding sites on the surface of collagen revealed the presence of a groove with sufficient space to accommodate raloxifene analogs. The hydroxyl groups on the benzothiophene nucleus, which are necessary for binding of SERMs to the estrogen receptor, are not required for binding to the bone surface, but mediate a more robust binding of the compound to the bone powder. In conclusion, we report herein a novel property of raloxifene analogs that allows them to interact with the bone tissue through potential contacts with the organic matrix and in particular collagen.

  19. Altered endochondral bone development in matrix metalloproteinase 13-deficient mice

    PubMed Central

    Stickens, Dominique; Behonick, Danielle J.; Ortega, Nathalie; Heyer, Babette; Hartenstein, Bettina; Yu, Ying; Fosang, Amanda J.; Schorpp-Kistner, Marina; Angel, Peter; Werb, Zena

    2009-01-01

    Summary The assembly and degradation of extracellular matrix (ECM) molecules are crucial processes during bone development. In this study, we show that ECM remodeling is a critical rate-limiting step in endochondral bone formation. Matrix metalloproteinase (MMP) 13 (collagenase 3) is poised to play a crucial role in bone formation and remodeling because of its expression both in terminal hypertrophic chondrocytes in the growth plate and in osteoblasts. Moreover, a mutation in the human MMP13 gene causes the Missouri variant of spondyloepimetaphyseal dysplasia. Inactivation of Mmp13 in mice through homologous recombination led to abnormal skeletal growth plate development. Chondrocytes differentiated normally but their exit from the growth plate was delayed. The severity of the Mmp13-null growth plate phenotype increased until about 5 weeks and completely resolved by 12 weeks of age. Mmp13-null mice had increased trabecular bone, which persisted for months. Conditional inactivation of Mmp13 in chondrocytes and osteoblasts showed that increases in trabecular bone occur independently of the improper cartilage ECM degradation caused by Mmp13 deficiency in late hypertrophic chondrocytes. Our studies identified the two major components of the cartilage ECM, collagen type II and aggrecan, as in vivo substrates for MMP13. We found that degradation of cartilage collagen and aggrecan is a coordinated process in which MMP13 works synergistically with MMP9. Mice lacking both MMP13 and MMP9 had severely impaired endochondral bone, characterized by diminished ECM remodeling, prolonged chondrocyte survival, delayed vascular recruitment and defective trabecular bone formation (resulting in drastically shortened bones). These data support the hypothesis that proper ECM remodeling is the dominant rate-limiting process for programmed cell death, angiogenesis and osteoblast recruitment during normal skeletal morphogenesis. PMID:15539485

  20. Bone Matrix Osteonectin Limits Prostate Cancer Cell Growth and Survival

    PubMed Central

    Kapinas, Kristina; Lowther, Katie M.; Kessler, Catherine B.; Tilbury, Karissa; Lieberman, Jay R.; Tirnauer, Jennifer S.; Campagnola, Paul; Delany, Anne M.

    2012-01-01

    There is considerable interest in understanding prostate cancer metastasis to bone and the interaction of these cells with the bone microenvironment. Osteonectin/SPARC/BM-40 is a collagen binding matricellular protein that is enriched in bone. Its expression is increased in prostate cancer metastases, and it stimulates the migration of prostate carcinoma cells. However, the presence of osteonectin in cancer cells and the stroma may limit prostate tumor development and progression. To determine how bone matrix osteonectin affects the behavior of prostate cancer cells, we modeled prostate cancer cell-bone interactions using the human prostate cancer cell line PC-3, and mineralized matrices synthesized by wild type and osteonectin-null osteoblasts in vitro. We developed this in vitro system because the structural complexity of collagen matrices in vivo is not mimicked by reconstituted collagen scaffolds or by more complex substrates, like basement membrane extracts. Second harmonic generation imaging demonstrated that the wild type matrices had thick collagen fibers organized into longitudinal bundles, whereas osteonectin-null matrices had thinner fibers in random networks. Importantly, a mouse model of prostate cancer metastases to bone showed a collagen fiber phenotype similar to the wild type matrix synthesized in vitro. When PC-3 cells were grown on the wild type matrices, they displayed decreased cell proliferation, increased cell spreading, and decreased resistance to radiation-induced cell death, compared to cells grown on osteonectin-null matrix. Our data support the idea that osteonectin can suppress prostate cancer pathogenesis, expanding this concept to the microenvironment of skeletal metastases. PMID:22525512

  1. Blueberry consumption prevents loss of collagen in bone matrix and inhibits senescence pathways in osteoblastic cells

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Ovariectomy (OVX)-induced bone loss has been linked to increased bone turnover and higher bone matrix collagen degradation as the result of osteoclast activation. However, the role of degraded collagen matrix in the fate of resident bone-forming cells is unclear. In this report, we show that OVX-i...

  2. Initial bone matrix formation at the hydroxyapatite interface in vivo.

    PubMed

    de Bruijn, J D; van Blitterswijk, C A; Davies, J E

    1995-01-01

    Dense, sintered, slip-cast hydroxyapatite rods were implanted transfemorally in young adult rats. The femora were excised after 2 and 4 weeks and, following fixation, either embedded in methyl methacrylate for light microscopy, decalcified and prepared for transmission electron microscopy, or freeze fractured in liquid nitrogen for scanning electron microscopic analysis. The latter was performed on the two tissue fragments that remained after freeze fracturing, from which the first contained the implants and the second comprised tissue that had been immediately adjacent to the hydroxyapatite rods. Undecalcified light microscopic sections revealed extensive bone tissue formation around and in contact with the hydroxyapatite rods. The initial bone matrix apposed to the implant surface, as demonstrated with scanning electron microscopy, was either composed of globular deposits or an organized network of collagen fibers. The deposits, which ranged in size from 0.1-1.1 microns, fused to form a cement-like matrix to which collagen fibers were attached. Degradation of the hydroxyapatite surface resulted in the presence of unidirectionally aligned crystallites, with which the newly formed bone matrix was closely associated. Ultrastructural analysis of the bone-hydroxyapatite interface with transmission electron microscopy revealed a 50-600-nm-wide collagen-free granular zone, comprising one or more 40-100-nm-thick electron-dense layer(s). These structural arrangements most probably partially represent the globular deposits and proteinaceous material adsorbed onto and partially in the degrading hydroxyapatite surface. Although the latter change in surface topography may have enhanced bonding of the cement-like matrix to the hydroxyapatite, the cause for this change in topography and the type of bond formed are, at present, unknown. PMID:7713963

  3. Use of demineralized bone matrix in spinal fusion

    PubMed Central

    Tilkeridis, Konstantinos; Touzopoulos, Panagiotis; Ververidis, Athanasios; Christodoulou, Sotirios; Kazakos, Konstantinos; Drosos, Georgios I

    2014-01-01

    Spinal fusion remains the gold-standard treatment for several pathological spine conditions. Although, autologous Iliac Crest Bone Grafting is considered the gold-standard graft choice to promote spinal fusion; however, it is associated with significant donor site morbidity and a limited graft quantity. Therefore, several bone graft alternatives have been developed, to augment arthrodesis. The purpose of this review is to present the results of clinical studies concerning the use of demineralized bone matrix (DBM), alone or as a composite graft, in the spinal fusion. A critical review of the English-language literature was conducted on Pubmed, using key word “demineralized bone matrix”, “DBM”, “spinal fusion”, and “scoliosis”. Results had been restricted to clinical studies. The majority of clinical trials demonstrate satisfactory fusion rates when DBM is employed as a graft extender or a graft enhancer. Limited number of prospective randomized controlled trials (4 studies), have been performed comparing DBM to autologous iliac crest bone graft in spine fusion. The majority of the clinical trials demonstrate comparable efficacy of DBM when it used as a graft extender in combination with autograft, but there is no clinical evidence to support its use as a standalone graft material. Additionally, high level of evidence studies are required, in order to optimize and clarify the indications of its use and the appropriate patient population that will benefit from DBM in spine arthrodesis. PMID:24649412

  4. Physicomechanical properties of the extracellular matrix of a demineralized bone

    NASA Astrophysics Data System (ADS)

    Kirilova, I. A.; Sharkeev, Yu. P.; Nikolaev, S. V.; Podorozhnaya, V. T.; Uvarkin, P. V.; Ratushnyak, A. S.; Chebodaeva, V. V.

    2016-08-01

    The article describes the results of a study of physicomechanical properties of a demineralized bone matrix of human cancellous and compact bones. A demineralized cancellous bone was shown to have the best characteristics of a porous system for colonization of matrices by cells. The ultimate stress and elasticity modulus of samples of demineralized femoral heads isolated in primary hip replacement was demonstrated to vary in wide ranges. The elasticity modulus ranged from 50 to 250 MPa, and the tensile strength varied from 1.1 to 5.5 MPa. Microhardness measurements by the recovered indentation method were not possible because of the viscoelastic properties of a bone material. To study the piezoelectric properties of samples, a measuring system was developed that comprised a measuring chamber with contact electrodes, a system for controlled sample loading, an amplifier-converter unit, and signal recording and processing software. The measurement results were used to determine the dependence of the signal amplitude on the dynamic deformation characteristics. The findings are discussed in terms of the relationship between the mechanical and electrical properties and the structure of the organic bone component.

  5. Remineralized Bone Matrix (RBM) as a Scaffold for Bone Tissue Engineering

    PubMed Central

    Soicher, Matthew A.; Christiansen, Blaine A.; Stover, Susan M.; Leach, J. Kent; Yellowley, Clare E.; Griffiths, Leigh G.; Fyhrie, David P.

    2014-01-01

    There is a need for improved biomaterials for use in treating non-healing bone defects. A number of natural and synthetic biomaterials have been used for the regeneration of bone tissue with mixed results. One approach is to modify native tissue via decellularization or other treatment for use as natural scaffolding for tissue repair. In this study, our goal was to improve on our previously published alternating solution immersion (ASI) method to fabricate a robust, biocompatible, and mechanically competent biomaterial from natural demineralized bone matrix (DBM). The improved method includes an antigen removal (AR) treatment step which improves mineralization and stiffness while removing unwanted proteins. The chemistry of the mineral in the remineralized bone matrix (RBM) was consistent with dicalcium phosphate dihydrate (brushite), a material used clinically in bone healing applications. Mass spectrometry identified proteins removed from the matrix with AR treatment to include α-2 HS-glycoprotein and osteopontin, non-collagenous proteins (NCPs) and known inhibitors of biomineralization. Additionally, the RBM supported the survival, proliferation, and differentiation of human mesenchymal stromal cells (MSCs) in vitro as well or better than other widely used biomaterials including DBM and PLG scaffolds. DNA content increased more than 10-fold on RBM compared to DBM and PLG; likewise, osteogenic gene expression was significantly increased after 1 and 2 weeks. We demonstrated that ASI remineralization has the capacity to fabricate mechanically stiff and biocompatible RBM, a suitable biomaterial for cell culture applications. PMID:24616346

  6. Milk extracellular vesicles accelerate osteoblastogenesis but impair bone matrix formation.

    PubMed

    Oliveira, Marina C; Arntz, Onno J; Blaney Davidson, Esmeralda N; van Lent, Peter L E M; Koenders, Marije I; van der Kraan, Peter M; van den Berg, Wim B; Ferreira, Adaliene V M; van de Loo, Fons A J

    2016-04-01

    The claimed beneficial effect of milk on bone is still a matter for debate. Recently extracellular vesicles (EVs) that contain proteins and RNA were discovered in milk, but their effect on bone formation has not yet been determined. We demonstrated previously that bovine milk-derived EVs (BMEVs) have immunoregulatory properties. Our aim was to evaluate the effect of BMEVs on osteogenesis by mice and human mesenchymal stem cells (hMSCs). Oral delivery of two concentrations of BMEVs to female DBA/1J mice during 7weeks did not alter the tibia trabecular bone area; however, the osteocytes number increased. In addition, the highest dose of BMEVs markedly increased the woven bone tissue, which is more brittle. The exposure of hMSCs to BMEVs during 21days resulted in less mineralization but higher cell proliferation. Interestingly BMEVs reduced the collagen production, but enhanced the expression of genes characteristic for immature osteoblasts. A kinetic study showed that BMEVs up-regulated many osteogenic genes within the first 4days. However, the production of type I collagen and expression of its genes (COL1A1 and COL1A2) were markedly reduced at days 21 and 28. At day 28, BMEVs again lead to higher proliferation, but mineralization was significantly increased. This was associated with increased expression of sclerostin, a marker for osteocytes, and reduced osteonectin, which is associated to bone matrix formation. Our study adds BMEVs to the list of milk components that can affect bone formation and may shed new light on the contradictory claims of milk on bone formation.

  7. Bone Reconstruction following Application of Bone Matrix Gelatin to Alveolar Defects: A Randomized Clinical Trial

    PubMed Central

    Bayat, M.; Momen Heravi, F.; Mahmoudi, M.; Bahrami, N.

    2015-01-01

    Background: Conventional dentoalveolar osseous reconstruction often involves the use of graft materials with or without barrier membranes. Objective: To evaluate the efficacy of bone induction by bone matrix gelatin (BMG), delivered on an absorbable collagen sponge (ACS), compared to a placebo (ACS alone) in human alveolar socket defects. Methods: 20 alveolar sockets from 10 healthy adults were studied. In all cases, both the mandibular premolar area and the contralateral premolar area (as the control site) were involved. In each of the 10 patients, the extraction sites were filled randomly with BMG and ACS. The repair response was examined on day 90. Qualitative histological and quantitative histometric analysis, including the percentage of new-formed bone fill and density were done. Results: Assessment of the alveolar bone indicated that patients treated with BMG had significantly (p<0.05) better bone quality and quantity compared to the controls. In addition, bone density and histology revealed no differences between the newly induced and native bone. Conclusion: The data from this single-blind clinical trial demonstrated that the novel combination of BMG had a striking effect on de novo osseous formation for the bone regeneration. PMID:26576263

  8. Hydrogels derived from demineralized and decellularized bone extracellular matrix

    PubMed Central

    Sawkins, M.J.; Bowen, W.; Dhadda, P.; Markides, H.; Sidney, L.E.; Taylor, A.J.; Rose, F.R.A.J.; Badylak, S.F.; Shakesheff, K.M.; White, L.J.

    2013-01-01

    The extracellular matrix (ECM) of mammalian tissues has been isolated, decellularized and utilized as a scaffold to facilitate the repair and reconstruction of numerous tissues. Recent studies have suggested that superior function and complex tissue formation occurred when ECM scaffolds were derived from site-specific homologous tissues compared with heterologous tissues. The objectives of the present study were to apply a stringent decellularization process to demineralized bone matrix (DBM), prepared from bovine bone, and to characterize the structure and composition of the resulting ECM materials and DBM itself. Additionally, we sought to produce a soluble form of DBM and ECM which could be induced to form a hydrogel. Current clinical delivery of DBM particles for treatment of bone defects requires incorporation of the particles within a carrier liquid. Differences in osteogenic activity, inflammation and nephrotoxicity have been reported with various carrier liquids. The use of hydrogel forms of DBM or ECM may reduce the need for carrier liquids. DBM and ECM hydrogels exhibited sigmoidal gelation kinetics consistent with a nucleation and growth mechanism, with ECM hydrogels characterized by lower storage moduli than the DBM hydrogels. Enhanced proliferation of mouse primary calvarial cells was achieved on ECM hydrogels, compared with collagen type I and DBM hydrogels. These results show that DBM and ECM hydrogels have distinct structural, mechanical and biological properties and have the potential for clinical delivery without the need for carrier liquids. PMID:23624219

  9. Enhanced release of bone morphogenetic proteins from demineralized bone matrix by gamma irradiation

    NASA Astrophysics Data System (ADS)

    Sung, Nak-Yun; Choi, Jong-il

    2015-06-01

    Gamma irradiation is a useful method for sterilizing demineralized bone matrix (DBM), but its effect on the osteoinductivity of DBM is still controversial. In this study, the osteoinductive activity of gamma-irradiated DBM was examined using a mouse myoblastic cell line (C2C12). DBM was extracted from adult bovine bone and was irradiated at a dose of 25 kGy using a 60cobalt gamma-irradiator. Cell proliferation with DBM was not affected by gamma-irradiation, but alkaline phosphatase and osteocalcin productions were significantly increased in C2C12 cell groups treated with gamma-irradiated DBM. It was reasoned that bone morphogenetic proteins were more efficiently released from gamma-irradiated DBM than from the non-irradiated control. This result suggests the effectiveness of radiation sterilization of bone implants

  10. Effect of rhBMP-2 Immobilized Anorganic Bovine Bone Matrix on Bone Regeneration

    PubMed Central

    Huh, Jung-Bo; Yang, June-Jip; Choi, Kyung-Hee; Bae, Ji Hyeon; Lee, Jeong-Yeol; Kim, Sung-Eun; Shin, Sang-Wan

    2015-01-01

    Anorganic bovine bone matrix (Bio-Oss®) has been used for a long time for bone graft regeneration, but has poor osteoinductive capability. The use of recombinant human bone morphogenetic protein-2 (rhBMP-2) has been suggested to overcome this limitation of Bio-Oss®. In the present study, heparin-mediated rhBMP-2 was combined with Bio-Oss® in animal experiments to investigate bone formation performance; heparin was used to control rhBMP-2 release. Two calvarial defects (8 mm diameter) were formed in a white rabbit model and then implanted or not (controls) with Bio-Oss® or BMP-2/Bio-Oss®. The Bio-Oss® and BMP-2/Bio-Oss® groups had significantly greater new bone areas (expressed as percentages of augmented areas) than the non-implanted controls at four and eight weeks after surgery, and the BMP-2/Bio-Oss® group (16.50 ± 2.87 (n = 6)) had significantly greater new bone areas than the Bio-Oss® group (9.43 ± 3.73 (n = 6)) at four weeks. These findings suggest that rhBMP-2 treated heparinized Bio-Oss® markedly enhances bone regeneration. PMID:26184187

  11. Gelatin-apatite bone mimetic co-precipitates incorporated within biopolymer matrix to improve mechanical and biological properties useful for hard tissue repair

    PubMed Central

    Won, Jong-Eun; El-Fiqi, Ahmed; Jegal, Seung-Hwan; Han, Cheol-Min; Lee, Eun-Jung; Knowles, Jonathan C

    2014-01-01

    Synthetic biopolymers are commonly used for the repair and regeneration of damaged tissues. Specifically targeting bone, the composite approach of utilizing inorganic components is considered promising in terms of improving mechanical and biological properties. We developed gelatin-apatite co-precipitates which mimic the native bone matrix composition within poly(lactide-co-caprolactone) (PLCL). Ionic reaction of calcium and phosphate with gelatin molecules enabled the co-precipitate formation of gelatin-apatite nanocrystals at varying ratios. The gelatin-apatite precipitates formed were carbonated apatite in nature, and were homogeneously distributed within the gelatin matrix. The incorporation of gelatin-apatite significantly improved the mechanical properties, including tensile strength, elastic modulus and elongation at break, and the improvement was more pronounced as the apatite content increased. Of note, the tensile strength increased to as high as 45 MPa (a four-fold increase vs. PLCL), the elastic modulus was increased up to 1500 MPa (a five-fold increase vs. PLCL), and the elongation rate was ∼240% (twice vs. PLCL). These results support the strengthening role of the gelatin-apatite precipitates within PLCL. The gelatin-apatite addition considerably enhanced the water affinity and the acellular mineral-forming ability in vitro in simulated body fluid; moreover, it stimulated cell proliferation and osteogenic differentiation. Taken together, the GAp-PLCL nanocomposite composition is considered to have excellent mechanical and biological properties, which hold great potential for use as bone regenerative matrices. PMID:23985536

  12. Synthetic biodegradable hydrogel delivery of demineralized bone matrix for bone augmentation in a rat model

    PubMed Central

    Kinard, Lucas A.; Dahlin, Rebecca L.; Lam, Johnny; Lu, Steven; Lee, Esther J.; Kasper, F. Kurtis; Mikos, Antonios G.

    2014-01-01

    There exists a strong clinical need for a more capable and robust method to achieve bone augmentation, and a system with fine-tuned delivery of demineralized bone matrix (DBM) has potential to meet that need. As such, the objective of the present study was to investigate a synthetic biodegradable hydrogel for the delivery of DBM for bone augmentation in a rat model. Oligo(poly(ethylene glycol) fumarate) (OPF) constructs were designed and fabricated by varying the content of rat-derived DBM particles (either 1:3, 1:1, or 3:1 DBM:OPF weight ratio on a dry basis) and using two DBM particle size ranges (50–150 or 150–250 μm). The physical properties of the constructs and the bioactivity of the DBM were evaluated. Select formulations (1:1 and 3:1 with 50–150 μm DBM) were evaluated in vivo compared to an empty control to investigate the effect of DBM dose and construct properties on bone augmentation. Overall, 3:1 constructs with higher DBM content achieved the greatest volume of bone augmentation exceeding 1:1 constructs and empty implants by 3-fold and 5-fold, respectively. As such, we have established that a synthetic, biodegradable hydrogel can function as a carrier for DBM, and that the volume of bone augmentation achieved by the constructs correlated directly to DBM dose. PMID:25046637

  13. [The impact of octacalcium phosphate on the dynamics of bone matrix formation in experimental bone defects].

    PubMed

    Gurin, A N; Grigoryan, A S; Fedotov, A Yu; Komlev, V S

    2016-01-01

    The aim of the study was to assess the interaction of of octacalcium phosphate (OCP) with bone matrix and cells and its impact on the process of bone generation. The survey was conducted on animal model: critical hipbone defect was created in 12 230-250 g Wister rats. The animals were then divided in two groups. In group 1 (6 animals) defect was left to heal under blood clot and in group 2 (6 animals) it was filled with OCP. Three animals with no defect served as a control group. It was showed significant (p<0.05) increase of the area of the newly formed bone tissue and its direct correlation with duration of observation.

  14. Arylamino methylene bisphosphonate derivatives as bone seeking matrix metalloproteinase inhibitors.

    PubMed

    Tauro, Marilena; Laghezza, Antonio; Loiodice, Fulvio; Agamennone, Mariangela; Campestre, Cristina; Tortorella, Paolo

    2013-11-01

    The complexity of matrix metalloproteinase inhibitors (MMPIs) design derives from the difficulty in carefully addressing their inhibitory activity towards the MMP isoforms involved in many pathological conditions. In particular, specific metalloproteinases, such as MMP-2 and MMP-9, are key regulators of the 'vicious cycle' occurring between tumor metastases growth and bone remodeling. In an attempt to devise new approaches to selective inhibitor derivatives, we describe novel bisphosphonate bone seeking MMP inhibitors (BP-MMPIs), capable to be selectively targeted and to overcome undesired side effects of broad spectrum MMPIs. In vitro activity (IC50 values) for each inhibitor was determined against MMP-2, -8, -9 and -14, because of their relevant role in skeletal development and renewal. The results show that BP-MMPIs reached IC50 values of enzymatic inhibition in the low micromolar range. Computational studies, used to rationalize some trends in the observed inhibitory profiles, suggest a possible differential binding mode in MMP-2 that explains the selective inhibition of this isoform. In addition, survival assay was conducted on J774 cell line, a well known model system used to evaluate the structure-activity relationship of BPs for inhibiting bone resorption. The resulting data, confirming the specific activity of BP-MMPIs, and their additional proved propensity to bind hydroxyapatite powder in vitro, suggest a potential use of BP-MMPIs in skeletal malignancies.

  15. Bone Formation is Affected by Matrix Advanced Glycation End Products (AGEs) In Vivo.

    PubMed

    Yang, Xiao; Mostafa, Ahmed Jenan; Appleford, Mark; Sun, Lian-Wen; Wang, Xiaodu

    2016-10-01

    Advanced glycation end products (AGEs) accumulate in bone extracellular matrix as people age. Although previous evidence shows that the accumulation of AGEs in bone matrix may impose significant effects on bone cells, the effect of matrix AGEs on bone formation in vivo is still poorly understood. To address this issue, this study used a unique rat model with autograft implant to investigate the in vivo response of bone formation to matrix AGEs. Fluorochrome biomarkers were sequentially injected into rats to label the dynamic bone formation in the presence of elevated levels of matrix AGEs. After sacrificing animals, dynamic histomorphometry was performed to determine mineral apposition rate (MAR), mineralized surface per bone surface (MS/BS), and bone formation rate (BFR). Finally, nanoindentation tests were performed to assess mechanical properties of newly formed bone tissues. The results showed that MAR, MS/BS, and BFR were significantly reduced in the vicinity of implant cores with high concentration of matrix AGEs, suggesting that bone formation activities by osteoblasts were suppressed in the presence of elevated matrix AGEs. In addition, MAR and BFR were found to be dependent on the surrounding environment of implant cores (i.e., cortical or trabecular tissues). Moreover, MS/BS and BFR were also dependent on how far the implant cores were away from the growth plate. These observations suggest that the effect of matrix AGEs on bone formation is dependent on the biological milieu around the implants. Finally, nanoindentation test results indicated that the indentation modulus and hardness of newly formed bone tissues were not affected by the presence of elevated matrix AGEs. In summary, high concentration of matrix AGEs may slow down the bone formation process in vivo, while imposing little effects on bone mineralization.

  16. Zinc-deficient diet decreases fetal long bone growth through decreased bone matrix formation in mice.

    PubMed

    Kim, Jung-Tak; Baek, Sang-Heum; Lee, Sang-Han; Park, Eui Kyun; Kim, Eun-Cheol; Kwun, In-Sook; Shin, Hong-In

    2009-02-01

    This study evaluated the effects of zinc on skeletal development during fetal development in pregnant ICR mice fed a zinc-deficient (3 mg/kg) or zinc-adequate (30 mg/kg) diet. We also included a group pair-fed with the zinc-deficient group to control for decreased appetite due to zinc deficiency. Developing fetuses at embryonic day 18.5 were removed by cesarean section, and the skeletal development was evaluated by histological analysis as well as by body weight and longitudinal growth measurement. Reduced maternal food intake in the zinc-deficient and pair-fed groups resulted in a marked and significant (P < .05) decrease in fetal weight compared to that of the zinc-adequate group. However, fetal length retardation in the pair-fed group was less marked than in the zinc-deficient group, suggesting that reduced supply of zinc from maternal circulation may play a role in longitudinal growth through skeletal development. The fetal developing tibia of the zinc-deficient group showed marked shortening of diaphysis and a mild narrowing of the hypertrophic chondrocyte zone width with increased osteoclast number, but there was no influence on the mineralization of bone matrix. This may be the result of reduced activation of osteoblasts and maturation of chondrocytes with increased osteoclastic activity, suggesting that zinc deficiency during the fetal development has a greater impact on the matrix formation of bone than the mineralization of bone matrix.

  17. Hertwig's epithelial root sheath cell behavior during initial acellular cementogenesis in rat molars.

    PubMed

    Yamamoto, Tsuneyuki; Yamamoto, Tomomaya; Yamada, Tamaki; Hasegawa, Tomoka; Hongo, Hiromi; Oda, Kimimitsu; Amizuka, Norio

    2014-11-01

    This study was designed to examine developing acellular cementum in rat molars by immunohistochemistry, to elucidate (1) how Hertwig's epithelial root sheath disintegrates and (2) whether epithelial sheath cells transform into cementoblasts through epithelial-mesenchymal transition (EMT). Initial acellular cementogenesis was divided into three developmental stages, which can be seen in three different portions of the root: portion 1, where the epithelial sheath is intact; portion 2, where the epithelial sheath becomes fragmented; and portion 3, where acellular cementogenesis begins. Antibodies against three kinds of matrix proteinases, which degrade epithelial sheath-maintaining factors, including basement membrane and desmosomes, were used to investigate proteolytic activity of the epithelial sheath. Tissue non-specific alkaline phosphatase (TNALP) and keratin were used to investigate EMT. Epithelial sheath cells showed immunoreactivity for all three enzymes at fragmentation, which suggests that epithelial sheath disintegration is enzymatically mediated. Dental follicle cells and cementoblasts showed intense immunoreactivity for TNALP, and from portion 1 through to 3, the reaction extended from the alveolar bone-related zone to the root-related zone. Cells possessing keratin/TNALP double immunoreactivity were virtually absent. Keratin-positive epithelial sheath cells showed negligible immunoreactivity for TNALP, and epithelial cells did not appear to migrate to the dental follicle. Together, these findings suggest that a transition phenotype between epithelial cells and cementoblasts does not exist in the developing dental follicle and hence that epithelial sheath cells do not undergo EMT during initial acellular cementogenesis. In brief, this study supports the notion that cementoblasts derive from the dental follicle. PMID:24859538

  18. Interaction between Cartilage Oligomeric Matrix Protein and Extracellular Matrix Protein 1 Mediates Endochondral Bone Growth

    PubMed Central

    Kong, Li; Tian, Qingyun; Guo, Fengjin; Mucignat, Maria T.; Perris, Roberto; Sercu, Sandy; Merregaert, Joseph; Di Cesare, Paul E.; Liu, Chuan-ju

    2010-01-01

    In an effort to define the biological functions of COMP, a functional genetic screen was performed. This led to the identification of extracellular matrix protein 1 (ECM1) as a novel COMP-associated partner. COMP directly binds to ECM1 both in vitro and in vivo. The EGF domain of COMP and the C-terminus of ECM1 mediate the interaction between them. COMP and ECM1 Colocalize in the Growth Plates in Vivo. ECM1 inhibits chondrocyte hypertrophy, matrix mineralization, and endochondral bone formation, and COMP overcomes the inhibition by ECM1. In addition, COMP-mediated neutralization of ECM1 inhibition depends on their interaction, since COMP largely fails to overcome the ECM1 inhibition in the presence of the EGF domain of COMP, which disturbs the association of COMP and ECM1. These findings provide the first evidence linking the association of COMP and ECM1 and the biological significance underlying the interaction between them in regulating endochondral bone growth. PMID:20138147

  19. Interstitial engraftment of adipose-derived stem cells into an acellular dermal matrix results in improved inward angiogenesis and tissue incorporation.

    PubMed

    Komatsu, Issei; Yang, Jun; Zhang, Ying; Levin, L Scott; Erdmann, Detlev; Klitzman, Bruce; Hollenbeck, Scott T

    2013-10-01

    Acellular dermal matrices (ADM) are commonly used in reconstructive procedures and rely on host cell invasion to become incorporated into host tissues. We investigated different approaches to adipose-derived stem cells (ASCs) engraftment into ADM to enhance this process. Lewis rat adipose-derived stem cells were isolated and grafted (3.0 × 10(5) cells) to porcine ADM disks (1.5 mm thick × 6 mm diameter) using either passive onlay or interstitial injection seeding techniques. Following incubation, seeding efficiency and seeded cell viability were measured in vitro. In addition, Eighteen Lewis rats underwent subcutaneous placement of ADM disk either as control or seeded with PKH67 labeled ASCs. ADM disks were seeded with ASCs using either onlay or injection techniques. On day 7 and or 14, ADM disks were harvested and analyzed for host cell infiltration. Onlay and injection techniques resulted in unique seeding patterns; however cell seeding efficiency and cell viability were similar. In-vivo studies showed significantly increased host cell infiltration towards the ASCs foci following injection seeding in comparison to control group (p < 0.05). Moreover, regional endothelial cell invasion was significantly greater in ASCs injected grafts in comparison to onlay seeding (p < 0.05). ADM can successfully be engrafted with ASCs. Interstitial engraftment of ASCs into ADM via injection enhances regional infiltration of host cells and angiogenesis, whereas onlay seeding showed relatively broad and superficial cell infiltration. These findings may be applied to improve the incorporation of avascular engineered constructs.

  20. A composite demineralized bone matrix--self assembling peptide scaffold for enhancing cell and growth factor activity in bone marrow.

    PubMed

    Hou, Tianyong; Li, Zhiqiang; Luo, Fei; Xie, Zhao; Wu, Xuehui; Xing, Junchao; Dong, Shiwu; Xu, Jianzhong

    2014-07-01

    The need for suitable bone grafts is high; however, there are limitations to all current graft sources, such as limited availability, the invasive harvest procedure, insufficient osteoinductive properties, poor biocompatibility, ethical problems, and degradation properties. The lack of osteoinductive properties is a common problem. As an allogenic bone graft, demineralized bone matrix (DBM) can overcome issues such as limited sources and comorbidities caused by invasive harvest; however, DBM is not sufficiently osteoinductive. Bone marrow has been known to magnify osteoinductive components for bone reconstruction because it contains osteogenic cells and factors. Mesenchymal stem cells (MSCs) derived from bone marrow are the gold standard for cell seeding in tissue-engineered biomaterials for bone repair, and these cells have demonstrated beneficial effects. However, the associated high cost and the complicated procedures limit the use of tissue-engineered bone constructs. To easily enrich more osteogenic cells and factors to DBM by selective cell retention technology, DBM is modified by a nanoscale self-assembling peptide (SAP) to form a composite DBM/SAP scaffold. By decreasing the pore size and increasing the charge interaction, DBM/SAP scaffolds possess a much higher enriching yield for osteogenic cells and factors compared with DBM alone scaffolds. At the same time, SAP can build a cellular microenvironment for cell adhesion, proliferation, and differentiation that promotes bone reconstruction. As a result, a suitable bone graft fabricated by DBM/SAP scaffolds and bone marrow represents a new strategy and product for bone transplantation in the clinic.

  1. Deficiency in acellular cementum and periodontal attachment in bsp null mice.

    PubMed

    Foster, B L; Soenjaya, Y; Nociti, F H; Holm, E; Zerfas, P M; Wimer, H F; Holdsworth, D W; Aubin, J E; Hunter, G K; Goldberg, H A; Somerman, M J

    2013-02-01

    Bone sialoprotein (BSP) is an extracellular matrix protein found in mineralized tissues of the skeleton and dentition. BSP is multifunctional, affecting cell attachment and signaling through an RGD integrin-binding region, and acting as a positive regulator for mineral precipitation by nucleating hydroxyapatite crystals. BSP is present in cementum, the hard tissue covering the tooth root that anchors periodontal ligament (PDL) attachment. To test our hypothesis that BSP plays an important role in cementogenesis, we analyzed tooth development in a Bsp null ((-/-)) mouse model. Developmental analysis by histology, histochemistry, and SEM revealed a significant reduction in acellular cementum formation on Bsp (-/-) mouse molar and incisor roots, and the cementum deposited appeared hypomineralized. Structural defects in cementum-PDL interfaces in Bsp (-/-) mice caused PDL detachment, likely contributing to the high incidence of incisor malocclusion. Loss of BSP caused progressively disorganized PDL and significantly increased epithelial down-growth with aging. Bsp (-/-) mice displayed extensive root and alveolar bone resorption, mediated by increased RANKL and the presence of osteoclasts. Results collected here suggest that BSP plays a non-redundant role in acellular cementum formation, likely involved in initiating mineralization on the root surface. Through its importance to cementum integrity, BSP is essential for periodontal function. PMID:23183644

  2. A novel peptide-modified and gene-activated biomimetic bone matrix accelerating bone regeneration.

    PubMed

    Pan, Haitao; Zheng, Qixin; Yang, Shuhua; Guo, Xiaodong; Wu, Bin; Zou, Zhenwei; Duan, Zhixia

    2014-08-01

    The osteogenic differentiation of bone marrow stromal cells (BMSCs) can be regulated by systemic or local growth factor, especially by transforming growth factor beta 1 (TGF-β1). However, how to maintain the bioactivity of exogenous TGF-β1 is a great challenge due to its short half-life time. The most promising solution is to transfer TGF-β1 gene into seed cells through transgenic technology and then transgenic cells to continuously secret endogenous TGF-β1 protein via gene expression. In this study, a novel non-viral vector (K)16GRGDSPC was chemically linked to bioactive bone matrices PLGA-[ASP-PEG]n using cross-linker to construct a novel non-viral gene transfer system. TGF-β1 gene was incubated with this system and subsequently rabbit-derived BMSCs were co-cultured with this gene-activated PLGA-[ASP-PEG]n, while co-cultured with PLGA-[ASP-PEG]n modified with (K)16GRGDSPC only and original PLGA-[ASP-PEG]n as control. Thus we fabricated three kinds of composites: Group A (BMSCs-TGF-β1DNA-(K)16GRGDSPC-PLGA-[ASP-PEG]n composite); Group B (BMSCs-(K)16GRGDSPC-PLGA-[ASP-PEG]n composite); and Group C (BMSCs-PLGA-[ASP-PEG]n composite). TGF-β1 and other osteogenic phenotype markers of alkaline phosphatase, osteocalcin, osteopontin and type I collagen in Group A were all significantly higher than the other two groups ex vivo. In vivo, 15-mm long segmental rabbit bone defects were created and randomly implanted the aforementioned composites separately, and then fixed with plate-screws. The results demonstrated that the implants in Group A significantly accelerated bone regeneration compared with the other implants based on X-rays, histological and biomechanical examinations. Therefore, we conclude this novel peptide-modified and gene-activated biomimetic bone matrix of TGF-β1DNA-(K)16GRGDSPC-PLGA-[ASP-PEG]n is a very promising scaffold biomaterial for accelerating bone regeneration. PMID:24115366

  3. A 3D printed nano bone matrix for characterization of breast cancer cell and osteoblast interactions

    NASA Astrophysics Data System (ADS)

    Zhu, Wei; Castro, Nathan J.; Cui, Haitao; Zhou, Xuan; Boualam, Benchaa; McGrane, Robert; Glazer, Robert I.; Zhang, Lijie Grace

    2016-08-01

    Bone metastasis is one of the most prevalent complications of late-stage breast cancer, in which the native bone matrix components, including osteoblasts, are intimately involved in tumor progression. The development of a successful in vitro model would greatly facilitate understanding the underlying mechanism of breast cancer bone invasion as well as provide a tool for effective discovery of novel therapeutic strategies. In the current study, we fabricated a series of in vitro bone matrices composed of a polyethylene glycol hydrogel and nanocrystalline hydroxyapatite of varying concentrations to mimic the native bone microenvironment for the investigation of breast cancer bone metastasis. A stereolithography-based three-dimensional (3D) printer was used to fabricate the bone matrices with precisely controlled architecture. The interaction between breast cancer cells and osteoblasts was investigated in the optimized bone matrix. Using a Transwell® system to separate the two cell lines, breast cancer cells inhibited osteoblast proliferation, while osteoblasts stimulated breast cancer cell growth, whereas, both cell lines increased IL-8 secretion. Breast cancer cells co-cultured with osteoblasts within the 3D bone matrix formed multi-cellular spheroids in comparison to two-dimensional monolayers. These findings validate the use of our 3D printed bone matrices as an in vitro metastasis model, and highlights their potential for investigating breast cancer bone metastasis.

  4. Utility of tricalcium phosphate and osteogenic matrix cell sheet constructs for bone defect reconstruction

    PubMed Central

    Ueha, Tomoyuki; Akahane, Manabu; Shimizu, Takamasa; Uchihara, Yoshinobu; Morita, Yusuke; Nitta, Naoya; Kido, Akira; Inagaki, Yusuke; Kawate, Kenji; Tanaka, Yasuhito

    2015-01-01

    AIM: To determine the effects of transplanting osteogenic matrix cell sheets and beta-tricalcium phosphate (TCP) constructs on bone formation in bone defects. METHODS: Osteogenic matrix cell sheets were prepared from bone marrow stromal cells (BMSCs), and a porous TCP ceramic was used as a scaffold. Three experimental groups were prepared, comprised of TCP scaffolds (1) seeded with BMSCs; (2) wrapped with osteogenic matrix cell sheets; or (3) both. Constructs were implanted into a femoral defect model in rats and bone growth was evaluated by radiography, histology, biochemistry, and mechanical testing after 8 wk. RESULTS: In bone defects, constructs implanted with cell sheets showed callus formation with segmental or continuous bone formation at 8 wk, in contrast to TCP seeded with BMSCs, which resulted in bone non-union. Wrapping TCP constructs with osteogenic matrix cell sheets increased their osteogenic potential and resulting bone formation, compared with conventional bone tissue engineering TCP scaffolds seeded with BMSCs. The compressive stiffness (mean ± SD) values were 225.0 ± 95.7, 30.0 ± 11.5, and 26.3 ± 10.6 MPa for BMSC/TCP/Sheet constructs with continuous bone formation, BMSC/TCP/Sheet constructs with segmental bone formation, and BMSC/TCP constructs, respectively. The compressive stiffness of BMSC/TCP/Sheet constructs with continuous bone formation was significantly higher than those with segmental bone formation and BMSC/TCP constructs. CONCLUSION: This technique is an improvement over current methods, such as TCP substitution, and is useful for hard tissue reconstruction and inducing earlier bone union in defects. PMID:26131318

  5. 3D printed nanocomposite matrix for the study of breast cancer bone metastasis.

    PubMed

    Zhu, Wei; Holmes, Benjamin; Glazer, Robert I; Zhang, Lijie Grace

    2016-01-01

    Bone is one of the most common metastatic sites of breast cancer, but the underlying mechanisms remain unclear, in part due to an absence of advanced platforms for cancer culture and study that mimic the bone microenvironment. In the present study, we integrated a novel stereolithography-based 3D printer and a unique 3D printed nano-ink consisting of hydroxyapatite nanoparticles suspended in hydrogel to create a biomimetic bone-specific environment for evaluating breast cancer bone invasion. Breast cancer cells cultured in a geometrically optimized matrix exhibited spheroid morphology and migratory characteristics. Co-culture of tumor cells with bone marrow mesenchymal stem cells increased the formation of spheroid clusters. The 3D matrix also allowed for higher drug resistance of breast cancer cells than 2D culture. These results validate that our 3D bone matrix can mimic tumor bone microenvironments, suggesting that it can serve as a tool for studying metastasis and assessing drug sensitivity. From the Clinical Editor: Cancer remains a major cause of mortality for patients in the clinical setting. For breast cancer, bone is one of the most common metastatic sites. In this intriguing article, the authors developed a bone-like environment using 3D printing technology to investigate the underlying biology of bone metastasis. Their results would also allow a new model for other researchers who work on cancer to use.

  6. Effects of Bone Matrix Proteins on Fracture and Fragility in Osteoporosis

    PubMed Central

    Sroga, Grażyna E.

    2012-01-01

    Bone mineral density alone cannot reliably predict fracture risk in humans and laboratory animals. Therefore, other factors including the quality of organic bone matrix components and their interactions may be of crucial importance to understanding of fragility fractures. Emerging research evidence shows, that in addition to collagen, certain noncollagenous proteins (NCPs) play a significant role in the structural organization of bone and influence its mechanical properties. However, their contribution to bone strength still remains largely undefined. Collagen and NCPs undergo different post-translational modifications, which alter the quality of the extracellular matrix and the response of bone to mechanical load. The primary focus of this overview is on NCPs that, together with collagen, contribute to structural and mechanical properties of bone. Current information on several mechanisms through which some NCPs influence bone’s resistance to fracture, including the role of nonenzymatic glycation, is also presented. PMID:22535528

  7. Microfluidic vascularized bone tissue model with hydroxyapatite-incorporated extracellular matrix.

    PubMed

    Jusoh, Norhana; Oh, Soojung; Kim, Sudong; Kim, Jangho; Jeon, Noo Li

    2015-10-21

    Current in vitro systems mimicking bone tissues fail to fully integrate the three-dimensional (3D) microvasculature and bone tissue microenvironments, decreasing their similarity to in vivo conditions. Here, we propose 3D microvascular networks in a hydroxyapatite (HA)-incorporated extracellular matrix (ECM) for designing and manipulating a vascularized bone tissue model in a microfluidic device. Incorporation of HA of various concentrations resulted in ECM with varying mechanical properties. Sprouting angiogenesis was affected by mechanically modulated HA-extracellular matrix interactions, generating a model of vascularized bone microenvironment. Using this platform, we observed that hydroxyapatite enhanced angiogenic properties such as sprout length, sprouting speed, sprout number, and lumen diameter. This new platform integrates fibrin ECM with the synthetic bone mineral HA to provide in vivo-like microenvironments for bone vessel sprouting.

  8. Differential expression of bone matrix regulatory proteins in human atherosclerotic plaques.

    PubMed

    Dhore, C R; Cleutjens, J P; Lutgens, E; Cleutjens, K B; Geusens, P P; Kitslaar, P J; Tordoir, J H; Spronk, H M; Vermeer, C; Daemen, M J

    2001-12-01

    In the present study, we examined the expression of regulators of bone formation and osteoclastogenesis in human atherosclerosis because accumulating evidence suggests that atherosclerotic calcification shares features with bone calcification. The most striking finding of this study was the constitutive immunoreactivity of matrix Gla protein, osteocalcin, and bone sialoprotein in nondiseased aortas and the absence of bone morphogenetic protein (BMP)-2, BMP-4, osteopontin, and osteonectin in nondiseased aortas and early atherosclerotic lesions. When atherosclerotic plaques demonstrated calcification or bone formation, BMP-2, BMP-4, osteopontin, and osteonectin were upregulated. Interestingly, this upregulation was associated with a sustained immunoreactivity of matrix Gla protein, osteocalcin, and bone sialoprotein. The 2 modulators of osteoclastogenesis (osteoprotegerin [OPG] and its ligand, OPGL) were present in the nondiseased vessel wall and in early atherosclerotic lesions. In advanced calcified lesions, OPG was present in bone structures, whereas OPGL was only present in the extracellular matrix surrounding calcium deposits. The observed expression patterns suggest a tight regulation of the expression of bone matrix regulatory proteins during human atherogenesis. The expression pattern of both OPG and OPGL during atherogenesis might suggest a regulatory role of these proteins not only in osteoclastogenesis but also in atherosclerotic calcification. PMID:11742876

  9. Remineralization of Demineralized Bone Matrix (DBM) via Alternating Solution Immersion (ASI)

    PubMed Central

    Soicher, Matthew A.; Christiansen, Blaine A.; Stover, Susan M.; Leach, J. Kent; Fyhrie, David P.

    2013-01-01

    In order to achieve successful clinical outcomes, biomaterials used for bone grafts must possess a number of traits including biocompatibility and osteoconductivity. These materials must also demonstrate appropriate mechanical stability to withstand handling as well as support potentially significant stresses at the implant site. Synthetic and natural polymer scaffolds used for bone tissue engineering (BTE) often lack necessary mechanical properties. Our goal was to internally mineralize natural collagenous matrix, thereby increasing mechanical properties of the material to useful levels. Published methods for intrafibrillar collagen mineralization were applied to clinically relevant-sized constructs but did not successfully deposit mineral in the interior of the constructs. To address this limitation, we developed a new technique for the remineralization of demineralized bone matrix (DBM) based on alternating solution immersion, or ASI. Mineral was removed from equine bone specimens, leaving behind a demineralized bone matrix (DBM). This matrix provides a framework for the nucleation and growth of a replacement mineral phase. Plain film radiography and microcomputed tomography (microCT) indicated accumulation of mineral within the DBM, and mechanical testing (3 point bending and compression) revealed a significant increase in stiffness between the DBM and the remineralized bone matrix (RBM). We believe this remineralization process will be useful in the preparation of stiff and strong allografts for clinical application. PMID:23759125

  10. Bone regeneration with osteogenically enhanced mesenchymal stem cells and their extracellular matrix proteins.

    PubMed

    Clough, Bret H; McCarley, Matthew R; Krause, Ulf; Zeitouni, Suzanne; Froese, Jeremiah J; McNeill, Eoin P; Chaput, Christopher D; Sampson, H Wayne; Gregory, Carl A

    2015-01-01

    Although bone has remarkable regenerative capacity, about 10% of long bone fractures and 25% to 40% of vertebral fusion procedures fail to heal. In such instances, a scaffold is employed to bridge the lesion and accommodate osteoprogenitors. Although synthetic bone scaffolds mimic some of the characteristics of bone matrix, their effectiveness can vary because of biological incompatibility. Herein, we demonstrate that a composite prepared with osteogenically enhanced mesenchymal stem cells (OEhMSCs) and their extracellular matrix (ECM) has an unprecedented capacity for the repair of critical-sized defects of murine femora. Furthermore, OEhMSCs do not cause lymphocyte activation, and ECM/OEhMSC composites retain their in vivo efficacy after cryopreservation. Finally, we show that attachment to the ECM by OEhMSCs stimulates the production of osteogenic and angiogenic factors. These data demonstrate that composites of OEhMSCs and their ECM could be utilized in the place of autologous bone graft for complex orthopedic reconstructions.

  11. HBM Mice Have Altered Bone Matrix Composition and Improved Material Toughness.

    PubMed

    Ross, Ryan D; Mashiatulla, Maleeha; Acerbo, Alvin S; Almer, Jonathan D; Miller, Lisa M; Johnson, Mark L; Sumner, D Rick

    2016-10-01

    The G171V mutation in the low-density lipoprotein receptor-related protein 5 (LRP5) leads to a high bone mass (HBM) phenotype. Studies using HBM transgenic mouse models have consistently found increased bone mass and whole-bone strength, but little attention has been paid to the composition of the bone matrix. The current study sought to determine if the cortical bone matrix composition differs in HBM and wild-type mice and to determine how much of the variance in bone material properties is explained by variance in matrix composition. Consistent with previous studies, HBM mice had greater cortical area, moment of inertia, ultimate force, bending stiffness, and energy to failure than wild-type animals. The increased energy to failure was primarily caused by a large increase in post-yield behavior, with no difference in pre-yield behavior. The HBM mice had increased mineral-to-matrix and collagen cross-link ratios, and decreased crystallinity, carbonate, and acid phosphate substitution as measured by Fourier transform infrared microspectroscopy, but no differences in crystal length, intra-fibular strains, and mineral spacing compared to wild-type controls, as measured by X-ray scattering. The largest between genotype difference in material properties was a twofold increase in the modulus of toughness in HBM mice. Step-wise regression analyses showed that the specific matrix compositional parameters most closely associated with material properties varied between the wild-type and HBM genotypes. Although the mechanisms controlling the paradoxical combination of more mineralized yet tougher bone in HBM mice remain to be fully explained, the findings suggest that LRP5 represents a target to not only build bone mass but also to improve bone quality. PMID:27230741

  12. HBM Mice Have Altered Bone Matrix Composition and Improved Material Toughness.

    PubMed

    Ross, Ryan D; Mashiatulla, Maleeha; Acerbo, Alvin S; Almer, Jonathan D; Miller, Lisa M; Johnson, Mark L; Sumner, D Rick

    2016-10-01

    The G171V mutation in the low-density lipoprotein receptor-related protein 5 (LRP5) leads to a high bone mass (HBM) phenotype. Studies using HBM transgenic mouse models have consistently found increased bone mass and whole-bone strength, but little attention has been paid to the composition of the bone matrix. The current study sought to determine if the cortical bone matrix composition differs in HBM and wild-type mice and to determine how much of the variance in bone material properties is explained by variance in matrix composition. Consistent with previous studies, HBM mice had greater cortical area, moment of inertia, ultimate force, bending stiffness, and energy to failure than wild-type animals. The increased energy to failure was primarily caused by a large increase in post-yield behavior, with no difference in pre-yield behavior. The HBM mice had increased mineral-to-matrix and collagen cross-link ratios, and decreased crystallinity, carbonate, and acid phosphate substitution as measured by Fourier transform infrared microspectroscopy, but no differences in crystal length, intra-fibular strains, and mineral spacing compared to wild-type controls, as measured by X-ray scattering. The largest between genotype difference in material properties was a twofold increase in the modulus of toughness in HBM mice. Step-wise regression analyses showed that the specific matrix compositional parameters most closely associated with material properties varied between the wild-type and HBM genotypes. Although the mechanisms controlling the paradoxical combination of more mineralized yet tougher bone in HBM mice remain to be fully explained, the findings suggest that LRP5 represents a target to not only build bone mass but also to improve bone quality.

  13. [The influence of mesenchymal stem cells on bone tissue regeneration upon implantation of demineralized bone matrix].

    PubMed

    Krugliakov, P V; Sokolova, I B; Zin'kova, N N; Viĭde, S V; Cherednichenko, N N; Kisliakova, T V; Polyntsev, D G

    2005-01-01

    Mesenchymal stem cells (MSC) are resident pluripotent cells of bone marrow stroma. MSC are able to differentiate into chondroblasts, adipocytes, neurons, glia, cardiomyocytes, or osteoblasts. The problem of MSC usage in cell therapy of bone defects is widely discussed at present. The experiments were carried out using rats of inbred line Wistar-Kyoto. MSC were isolated from bone marrow and cultivated in vitro. Demineralized bone matrices (DBM) were obtained from parietal bones of rats and hens. Part of DBM was loaded with MSC. Bone defects were made in cranium parietal regions. DBM with or without MSC or metal plates were transplanted in these regions. It was shown that the application of MSC increased angiogenesis and osteogenesis in the damaged bone. The implantation of rat's DBM with MSC led to the formation of a full value bone. MSC suppressed inflammation, when transplantation of hen's DBM was carried out. The application of MSC always improved bone tissue regeneration.

  14. Postraumatic frontal sinus obliteration with calvarial bone dust and demineralized bone matrix: a long term prospective study and literature review.

    PubMed

    Rodríguez, I Z; Uceda, M I F; Lobato, R D; Aniceto, G S

    2013-01-01

    Defining the ideal material for frontal sinus obliteration remains controversial. Autogenous cancellous bone is effective because of its biological properties: it undergoes fast revascularization acting as an active scaffold for bone healing, but is linked to additional donor site morbidity. Bone dust harvesting from the skull surface produces no sequelae but availability is limited. Many efforts have been made to overcome these drawbacks, and an ideal bone substitute sought. Demineralized Bone Matrix (DBX; Musculoskeletal Transplant Foundation, Edison, NJ, USA) is a commercially available product composed of demineralized bone particles reduced after proper processing of human bone in combination with sodium hyaluronate. It generates an osteoconductive surface and it is also a source of osteoinductive factors. Radiological follow-up using computed tomography is a very reliable method of following-up ossification and detecting the early signs of possible complications. The authors present their clinical series of postraumatic frontal sinus obliteration using a mixture of calvarial bone dust and DBX shell, with long-term radiological monitoring. The technique was demonstrated to be effective, reliable, stable in the long term and associated with minimal morbidity.

  15. Osteogenic ability of bone marrow stem cells intraoperatively enriched by a novel matrix.

    PubMed

    Ye, Qing; Chen, Kaining; Huang, Wu; He, Yunsong; Nong, Mingshan; Li, Chunxiang; Liang, Tiansen

    2015-01-01

    Poly-L-lysine (PLL) is commonly used as an adhibiting agent due to its good viscosity, and demineralized bone matrix (DBM) is a common enriched matrix for selective cell retention technology. Therefore, the aim of this study was to use PLL to coat the surface and interspaces of DBM to form a novel type of enriched matrix [DBM coated with PLL (PLL-DBM)], in order to effectively improve the enrichment effects of bone marrow stem cells and enhance their osteogenic ability. Electron microscope scanning and the infrared spectrum were used to observe the structure of PLL-DBM and the optimal conditions for the combination of PLL and DBM. Enriching effects on bone marrow nucleated cells (NCs) and platelets (PLTs) were detected with an automated hematology analyzer. The osteogenesis of the following four groups was assessed with a grafting bone model in a goat spinal transverse process: IA, tissue engineered bone (TEB) fabricated following enrichment of bone marrow with PLL-DBM; IB, autogenous iliac bone; IIC, TEB fabricated following enrichment of bone marrow with DBM; IID, blank DBM. The goats were sacrificed in one batch at week 16 after the surgery and the fusion specimens were examined using X-ray and three-dimensional computed tomography (CT). In addition, the CT value was determined and the histology and biomechanics were analyzed in order to evaluate the osteogenic ability. The results showed that PLL and DBM combined well and that PLL-DBM exhibited a natural mesh pore structure. The fold enrichment of NCs and PLTs with PLL-DBM was significantly higher than that with DBM. The fusion effects of the IA and IB groups were similar and significantly enhanced compared with those of the IIC and IID groups. The results confirmed that PLL-DBM is an ideal enriched matrix for bone marrow stem cells, and TEB rapidly fabricated by PLL-DBM intraoperatively enriched bone marrow stem cells exhibits an improved osteogenic ability.

  16. Endochondral bone formation in gelatin methacrylamide hydrogel with embedded cartilage-derived matrix particles.

    PubMed

    Visser, Jetze; Gawlitta, Debby; Benders, Kim E M; Toma, Selynda M H; Pouran, Behdad; van Weeren, P René; Dhert, Wouter J A; Malda, Jos

    2015-01-01

    The natural process of endochondral bone formation in the growing skeletal system is increasingly inspiring the field of bone tissue engineering. However, in order to create relevant-size bone grafts, a cell carrier is required that ensures a high diffusion rate and facilitates matrix formation, balanced by its degradation. Therefore, we set out to engineer endochondral bone in gelatin methacrylamide (GelMA) hydrogels with embedded multipotent stromal cells (MSCs) and cartilage-derived matrix (CDM) particles. CDM particles were found to stimulate the formation of a cartilage template by MSCs in the GelMA hydrogel in vitro. In a subcutaneous rat model, this template was subsequently remodeled into mineralized bone tissue, including bone-marrow cavities. The GelMA was almost fully degraded during this process. There was no significant difference in the degree of calcification in GelMA with or without CDM particles: 42.5 ± 2.5% vs. 39.5 ± 8.3% (mean ± standard deviation), respectively. Interestingly, in an osteochondral setting, the presence of chondrocytes in one half of the constructs fully impeded bone formation in the other half by MSCs. This work offers a new avenue for the engineering of relevant-size bone grafts, by the formation of endochondral bone within a degradable hydrogel.

  17. Aluminum and iron can be deposited in the calcified matrix of bone exostoses.

    PubMed

    Chappard, Daniel; Mabilleau, Guillaume; Moukoko, Didier; Henric, Nicolas; Steiger, Vincent; Le Nay, Patrick; Frin, Jean-Marie; De Bodman, Charlotte

    2015-11-01

    Exostosis (or osteochondroma) is the most common benign bone tumor encountered in children and adults. Exostoses may occur as solitary or multiple tumors (in the autosomal syndromes of hereditary multiple exostoses). Exostoses are composed of cortical and medullary bone covered by an overlying hyaline cartilage cap. We have searched iron (Fe) and aluminum (Al) in the matrix of cortical and trabecular bone of 30 patients with exostosis. Al(3+) and Fe(3+) are two cations which can substitute calcium in the hydroxyapatite crystals of the bone matrix. The bone samples were removed surgically and were studied undecalcified. Perls' Prussian blue staining (for Fe) and solochrome azurine B (for Al) were used on the histological sections of the tumors. Al(3+) was detected histochemically in 21/30 patients as linear bands deposited by the osteoblasts. Fe(3+) was detected in 10 out of these 21 patients as linear bands in the same locations. Fe(3+) and Al(3+) were not identified in the bone matrix of a control group of 20 osteoporotic patients. Energy X-ray Dispersive Spectrometry failed to identify Fe and Al in bone of these tumors due to the low sensitivity of the method. Wavelength Dispersive Spectrometry identified them but the concentrations were very low. Histochemistry appears a very sensitive method for Fe(3+) and Al(3+) in bone.The presence of these two metals in the exostoses advocates for a disturbed metabolism of osteoblasts which can deposit these metals into the bone matrix, similar to which is observed in case of hemochromatosis with Fe(3+).

  18. A Surrogate Measure of Cortical Bone Matrix Density by Long T2 -Suppressed MRI.

    PubMed

    Seifert, Alan C; Li, Cheng; Wehrli, Suzanne L; Wehrli, Felix W

    2015-12-01

    Magnetic resonance has the potential to image and quantify two pools of water within bone: free water within the Haversian pore system (transverse relaxation time, T2 > 1 ms), and water hydrogen-bonded to matrix collagen (T2 ∼ 300 to 400 μs). Although total bone water concentration quantified by MRI has been shown to scale with porosity, greater insight into bone matrix density and porosity may be gained by relaxation-based separation of bound and pore water fractions. The objective of this study was to evaluate a recently developed surrogate measurement for matrix density, single adiabatic inversion recovery (SIR) zero echo-time (ZTE) MRI, in human bone. Specimens of tibial cortical bone from 15 donors (aged 27 to 97 years; 8 female and 7 male) were examined at 9.4T field strength using two methods: (1) (1)H ZTE MRI, to capture total (1)H signal, and (2) (1)H SIR-ZTE MRI, to selectively image matrix-associated (1)H signal. Total water, bone matrix, and bone mineral densities were also quantified gravimetrically, and porosity was measured by micro-CT. ZTE apparent total water (1)H concentration was 32.7 ± 3.2 M (range 28.5 to 40.3 M), and was correlated positively with porosity (R(2) = 0.80) and negatively with matrix and mineral densities (R(2) =  0.90 and 0.82, respectively). SIR-ZTE apparent bound water (1)H concentration was 32.9 ± 3.9 M (range 24.4 to 39.8 M), and its correlations were opposite to those of apparent total water: negative with porosity (R(2) = 0.73) and positive with matrix density (R(2) = 0.74) and mineral density (R(2) = 0.72). Porosity was strongly correlated with gravimetric matrix density (R(2) = 0.91, negative) and total water density (R(2) = 0.92, positive). The strong correlations of SIR-ZTE-derived apparent bound water (1)H concentration with ground-truth measurements suggest that this quantitative solid-state MRI method provides a nondestructive surrogate measure of bone matrix density

  19. Acellular organ scaffolds for tumor tissue engineering

    NASA Astrophysics Data System (ADS)

    Guller, Anna; Trusova, Inna; Petersen, Elena; Shekhter, Anatoly; Kurkov, Alexander; Qian, Yi; Zvyagin, Andrei

    2015-12-01

    Rationale: Tissue engineering (TE) is an emerging alternative approach to create models of human malignant tumors for experimental oncology, personalized medicine and drug discovery studies. Being the bottom-up strategy, TE provides an opportunity to control and explore the role of every component of the model system, including cellular populations, supportive scaffolds and signalling molecules. Objectives: As an initial step to create a new ex vivo TE model of cancer, we optimized protocols to obtain organ-specific acellular matrices and evaluated their potential as TE scaffolds for culture of normal and tumor cells. Methods and results: Effective decellularization of animals' kidneys, ureter, lungs, heart, and liver has been achieved by detergent-based processing. The obtained scaffolds demonstrated biocompatibility and growthsupporting potential in combination with normal (Vero, MDCK) and tumor cell lines (C26, B16). Acellular scaffolds and TE constructs have been characterized and compared with morphological methods. Conclusions: The proposed methodology allows creation of sustainable 3D tumor TE constructs to explore the role of organ-specific cell-matrix interaction in tumorigenesis.

  20. Hybrid Matrix Grafts to Favor Tissue Regeneration in Rabbit Femur Bone Lesions

    PubMed Central

    Goy, Dante Pascual; Gorosito, Emmanuel; Costa, Hermes S; Mortarino, Pablo; Pedemonte, Noelia Acosta; Toledo, Javier; Mansur, Herman S; Pereira, Marivalda M; Battaglino, Ricardo; Feldman, Sara

    2012-01-01

    At present, typical approaches employed to repair fractures and other bone lesions tend to use matrix grafts to promote tissue regeneration. These grafts act as templates, which promote cellular adhesion, growth and proliferation, osteoconduction, and even osteoinduction, which commonly results in de novo osteogenesis. The present work aimed to study the bone-repairing ability of hybrid matrixes (HM) prepared with polyvinyl alcohol (PVA) and bioactive glass in an experimental rabbit model. The HM were prepared by combining 30% bioactive glass (nominal composition of 58% SiO2 -33 % CaO - 9% P2O5) and 70% PVA. New Zealand rabbits were randomly divided into the control group (C group) and two groups with bone lesions, in which one received a matrix implant HM (Implant group), while the other did not (no Implant group). Clinical monitoring showed no altered parameters from either the Implant or the no Implant groups as compared to the control group, for the variables of diet grades, day and night temperatures and hemograms. In the Implant group, radiologic and tomographic studies showed implanted areas with clean edges in femoral non-articular direction, and radio-dense images that suggest incipient integration. Minimum signs of phlogosis could be observed, whereas no signs of rejection at this imaging level could be identified. Histological analysis showed evidence of osteo-integration, with the formation of a trabecular bone within the implant. Together, these results show that implants of hybrid matrixes of bioactive glass are capable of promoting bone regeneration. PMID:22848334

  1. Ultrastructural studies on the origin and structure of matrix vesicles in bone of young rats.

    PubMed

    Ornoy, A; Atkin, I; Levy, J

    1980-01-01

    Tibiae of young rats were examined by scanning electron microscopy (SEM) and transmission electron microscopy (TEM) in order to study the origin and structure of matrix vesicles in periosteal bone. SEM studies have shown that periosteal osteoblasts have elongated processes with globular structures of 0.1 micron in diameter attached to the cell surface and processes. Similar structures were found to cover the inner surface of osteoblastic lacunae. The SEM studies have further shown that in the periosteal surface (forming bone) the above-described globules once mineralized, aggregated to form larger, nonhomogeneous mineralized spherules in which, by proper treatment with NaOCl, hydroxyapatite crystals could be exposed. Endosteal osteoblasts had fewer processes, devoid of the globular structures. Similarly, osteocytic and osteoclastic processes, although elongated and numberous, were not covered by the globular structures. In the matrix, collagen fibers of forming bone were randomly orientated, while in the deeper areas of bone they formed bundles with a longitudinal orientation. TEM studies have shown that the structures found on the osteoblastic surface and in the matrix are membrane-bound matrix vesicles which seem to be formed by budding from cell processes. Preformed membrane-bound vesicles were also observed by TEM inside sections of osteoblastic processes. These vesicles resembled the extracellular matrix vesicles in size and shape, thus giving the impression that at least some of the matrix vesicles are preformed cellular structures. While comparing SEM with TEM, it can be conducted that in bone, as in cartilage, matrix vesicles which probably serve as the initial locus of calcification, are formed directly by osteoblasts. PMID:7386166

  2. Ultrastructural studies on the origin and structure of matrix vesicles in bone of young rats.

    PubMed

    Ornoy, A; Atkin, I; Levy, J

    1980-01-01

    Tibiae of young rats were examined by scanning electron microscopy (SEM) and transmission electron microscopy (TEM) in order to study the origin and structure of matrix vesicles in periosteal bone. SEM studies have shown that periosteal osteoblasts have elongated processes with globular structures of 0.1 micron in diameter attached to the cell surface and processes. Similar structures were found to cover the inner surface of osteoblastic lacunae. The SEM studies have further shown that in the periosteal surface (forming bone) the above-described globules once mineralized, aggregated to form larger, nonhomogeneous mineralized spherules in which, by proper treatment with NaOCl, hydroxyapatite crystals could be exposed. Endosteal osteoblasts had fewer processes, devoid of the globular structures. Similarly, osteocytic and osteoclastic processes, although elongated and numberous, were not covered by the globular structures. In the matrix, collagen fibers of forming bone were randomly orientated, while in the deeper areas of bone they formed bundles with a longitudinal orientation. TEM studies have shown that the structures found on the osteoblastic surface and in the matrix are membrane-bound matrix vesicles which seem to be formed by budding from cell processes. Preformed membrane-bound vesicles were also observed by TEM inside sections of osteoblastic processes. These vesicles resembled the extracellular matrix vesicles in size and shape, thus giving the impression that at least some of the matrix vesicles are preformed cellular structures. While comparing SEM with TEM, it can be conducted that in bone, as in cartilage, matrix vesicles which probably serve as the initial locus of calcification, are formed directly by osteoblasts.

  3. Modifications in bone matrix of estrogen-deficient rats treated with intermittent PTH.

    PubMed

    Pacheco-Costa, Rafael; Campos, Jenifer Freitas; Katchburian, Eduardo; de Medeiros, Valquíria Pereira; Nader, Helena Bonciani; Nonaka, Keico Okino; Plotkin, Lilian Irene; Reginato, Rejane Daniele

    2015-01-01

    Bone matrix dictates strength, elasticity, and stiffness to the bone. Intermittent parathyroid hormone (iPTH), a bone-forming treatment, is widely used as a therapy for osteoporosis. We investigate whether low doses of intermittent PTH (1-34) change the profile of organic components in the bone matrix after 30 days of treatment. Forty 6-month-old female Wistar rats underwent ovariectomy and after 3 months received low doses of iPTH administered for 30 days: daily at 0.3 µg/kg/day (PTH03) or 5 µg/kg/day (PTH5); or 3 times per week at 0.25 µg/kg/day (PTH025). After euthanasia, distal femora were processed for bone histomorphometry, histochemistry for collagen and glycosaminoglycans, biochemical quantification of sulfated glycosaminoglycans, and hyaluronan by ELISA and TUNEL staining. Whole tibiae were used to estimate the bone mineral density (BMD). Histomorphometric analysis showed that PTH5 increased cancellous bone volume by 6% over vehicle-treated rats. In addition, PTH5 and PTH03 increased cortical thickness by 21% and 20%, respectively. Tibial BMD increased in PTH5-treated rats and this group exhibited lower levels of chondroitin sulfate; on the other hand, hyaluronan expression was increased. Hormonal administration in the PTH5 group led to decreased collagen maturity. Further, TUNEL-positive osteocytes were decreased in the cortical compartment of PTH5 whereas administration of PTH025 increased the osteocyte death. Our findings suggest that daily injections of PTH at low doses alter the pattern of organic components from the bone matrix, favoring the increase of bone mass. PMID:25695082

  4. Ultra-structural defects cause low bone matrix stiffness despite high mineralization in osteogenesis imperfecta mice☆

    PubMed Central

    Vanleene, Maximilien; Porter, Alexandra; Guillot, Pascale-Valerie; Boyde, Alan; Oyen, Michelle; Shefelbine, Sandra

    2012-01-01

    Bone is a complex material with a hierarchical multi-scale organization from the molecule to the organ scale. The genetic bone disease, osteogenesis imperfecta, is primarily caused by mutations in the collagen type I genes, resulting in bone fragility. Because the basis of the disease is molecular with ramifications at the whole bone level, it provides a platform for investigating the relationship between structure, composition, and mechanics throughout the hierarchy. Prior studies have individually shown that OI leads to: 1. increased bone mineralization, 2. decreased elastic modulus, and 3. smaller apatite crystal size. However, these have not been studied together and the mechanism for how mineral structure influences tissue mechanics has not been identified. This lack of understanding inhibits the development of more accurate models and therapies. To address this research gap, we used a mouse model of the disease (oim) to measure these outcomes together in order to propose an underlying mechanism for the changes in properties. Our main finding was that despite increased mineralization, oim bones have lower stiffness that may result from the poorly organized mineral matrix with significantly smaller, highly packed and disoriented apatite crystals. Using a composite framework, we interpret the lower oim bone matrix elasticity observed as the result of a change in the aspect ratio of apatite crystals and a disruption of the crystal connectivity. PMID:22449447

  5. PTH(1-84) Administration in Hypoparathyroidism Transiently Reduces Bone Matrix Mineralization.

    PubMed

    Misof, Barbara M; Roschger, Paul; Dempster, David W; Zhou, Hua; Bilezikian, John P; Klaushofer, Klaus; Rubin, Mishaela R

    2016-01-01

    Patients with hypoparathyroidism have low circulating parathyroid (PTH) levels and higher cancellous bone volume and trabecular thickness. Treatment with PTH(1-84) was shown to increase abnormally low bone remodeling dynamics. In this work, we studied the effect of 1-year or 2-year PTH(1-84) treatment on cancellous and cortical bone mineralization density distribution (Cn.BMDD and Ct.BMDD) based on quantitative backscattered electron imaging (qBEI) in paired transiliac bone biopsy samples. The study cohort comprised 30 adult hypoparathyroid patients (14 treated for 1 year; 16 treated for 2 years). At baseline, Cn.BMDD was shifted to higher mineralization densities in both treatment groups (average degree of mineralization Cn.CaMean +3.9% and +2.7%, p < 0.001) compared to reference BMDD. After 1-year PTH(1-84), Cn.CaMean was significantly lower than that at baseline (-6.3%, p < 0.001), whereas in the 2-year PTH(1-84) group Cn.CaMean did not differ from baseline. Significant changes of Ct.BMDD were observed in the 1-year treatment group only. The change in histomorphometric bone formation (mineralizing surface) was predictive for Cn.BMDD outcomes in the 1-year PTH(1-84) group, but not in the 2-year PTH(1-84) group. Our findings suggest higher baseline bone matrix mineralization consistent with the decreased bone turnover in hypoparathyroidism. PTH(1-84) treatment caused differential effects dependent on treatment duration that were consistent with the histomorphometric bone formation outcomes. The greater increase in bone formation during the first year of treatment was associated with a decrease in bone matrix mineralization, suggesting that PTH(1-84) exposure to the hypoparathyroid skeleton has the greatest effects on BMDD early in treatment.

  6. Aluminum and bone: Review of new clinical circumstances associated with Al(3+) deposition in the calcified matrix of bone.

    PubMed

    Chappard, D; Bizot, P; Mabilleau, G; Hubert, L

    2016-06-01

    Several decades ago, aluminum encephalopathy associated with osteomalacia has been recognized as the major complication of chronic renal failure in dialyzed patients. Removal of aluminum from the dialysate has led to a disappearance of the disease. However, aluminum deposit occurs in the hydroxyapatite of the bone matrix in some clinical circumstances that are presented in this review. We have encountered aluminum in bone in patients with an increased intestinal permeability (coeliac disease), or in the case of prolonged administration of aluminum anti-acid drugs. A colocalisation of aluminum with iron was also noted in cases of hemochromatosis and sickle cell anemia. Aluminium was also identified in a series of patients with exostosis, a frequent benign bone tumor. Corrosion of prosthetic implants composed of grade V titanium (TA6V is an alloy containing 6% aluminum and 4% vanadium) was also observed in a series of hip or knee revisions. Aluminum can be identified in undecalcified bone matrix stained by solochrome azurine, a highly specific stain allowing the detection of 0.03 atomic %. Colocalization of aluminum and iron does not seem to be the fruit of chance but the cellular and molecular mechanisms are still poorly understood. Histochemistry is superior to spectroscopic analyses (EDS and WDS in scanning electron microscopy).

  7. Multiscale alterations in bone matrix quality increased fragility in steroid induced osteoporosis.

    PubMed

    Karunaratne, A; Xi, L; Bentley, L; Sykes, D; Boyde, A; Esapa, C T; Terrill, N J; Brown, S D M; Cox, R D; Thakker, R V; Gupta, H S

    2016-03-01

    A serious adverse clinical effect of glucocorticoid steroid treatment is secondary osteoporosis, enhancing fracture risk in bone. This rapid increase in bone fracture risk is largely independent of bone loss (quantity), and must therefore arise from degradation of the quality of the bone matrix at the micro- and nanoscale. However, we lack an understanding of both the specific alterations in bone quality n steroid-induced osteoporosis as well as the mechanistic effects of these changes. Here we demonstrate alterations in the nanostructural parameters of the mineralized fibrillar collagen matrix, which affect bone quality, and develop a model linking these to increased fracture risk in glucocorticoid induced osteoporosis. Using a mouse model with an N-ethyl-N-nitrosourea (ENU)-induced corticotrophin releasing hormone promoter mutation (Crh(-120/+)) that developed hypercorticosteronaemia and osteoporosis, we utilized in situ mechanical testing with small angle X-ray diffraction, synchrotron micro-computed tomography and quantitative backscattered electron imaging to link altered nano- and microscale deformation mechanisms in the bone matrix to abnormal macroscopic mechanics. We measure the deformation of the mineralized collagen fibrils, and the nano-mechanical parameters including effective fibril modulus and fibril to tissue strain ratio. A significant reduction (51%) of fibril modulus was found in Crh(-120/+) mice. We also find a much larger fibril strain/tissue strain ratio in Crh(-120/+) mice (~1.5) compared to the wild-type mice (~0.5), indicative of a lowered mechanical competence at the nanoscale. Synchrotron microCT show a disruption of intracortical architecture, possibly linked to osteocytic osteolysis. These findings provide a clear quantitative demonstration of how bone quality changes increase macroscopic fragility in secondary osteoporosis. PMID:26657825

  8. Multiscale alterations in bone matrix quality increased fragility in steroid induced osteoporosis

    PubMed Central

    Karunaratne, A.; Xi, L.; Bentley, L.; Sykes, D.; Boyde, A.; Esapa, C.T.; Terrill, N.J.; Brown, S.D.M.; Cox, R.D.; Thakker, R.V.; Gupta, H.S.

    2016-01-01

    A serious adverse clinical effect of glucocorticoid steroid treatment is secondary osteoporosis, enhancing fracture risk in bone. This rapid increase in bone fracture risk is largely independent of bone loss (quantity), and must therefore arise from degradation of the quality of the bone matrix at the micro- and nanoscale. However, we lack an understanding of both the specific alterations in bone quality n steroid-induced osteoporosis as well as the mechanistic effects of these changes. Here we demonstrate alterations in the nanostructural parameters of the mineralized fibrillar collagen matrix, which affect bone quality, and develop a model linking these to increased fracture risk in glucocorticoid induced osteoporosis. Using a mouse model with an N-ethyl-N-nitrosourea (ENU)-induced corticotrophin releasing hormone promoter mutation (Crh− 120/+) that developed hypercorticosteronaemia and osteoporosis, we utilized in situ mechanical testing with small angle X-ray diffraction, synchrotron micro-computed tomography and quantitative backscattered electron imaging to link altered nano- and microscale deformation mechanisms in the bone matrix to abnormal macroscopic mechanics. We measure the deformation of the mineralized collagen fibrils, and the nano-mechanical parameters including effective fibril modulus and fibril to tissue strain ratio. A significant reduction (51%) of fibril modulus was found in Crh− 120/+ mice. We also find a much larger fibril strain/tissue strain ratio in Crh− 120/+ mice (~ 1.5) compared to the wild-type mice (~ 0.5), indicative of a lowered mechanical competence at the nanoscale. Synchrotron microCT show a disruption of intracortical architecture, possibly linked to osteocytic osteolysis. These findings provide a clear quantitative demonstration of how bone quality changes increase macroscopic fragility in secondary osteoporosis. PMID:26657825

  9. Multiscale alterations in bone matrix quality increased fragility in steroid induced osteoporosis.

    PubMed

    Karunaratne, A; Xi, L; Bentley, L; Sykes, D; Boyde, A; Esapa, C T; Terrill, N J; Brown, S D M; Cox, R D; Thakker, R V; Gupta, H S

    2016-03-01

    A serious adverse clinical effect of glucocorticoid steroid treatment is secondary osteoporosis, enhancing fracture risk in bone. This rapid increase in bone fracture risk is largely independent of bone loss (quantity), and must therefore arise from degradation of the quality of the bone matrix at the micro- and nanoscale. However, we lack an understanding of both the specific alterations in bone quality n steroid-induced osteoporosis as well as the mechanistic effects of these changes. Here we demonstrate alterations in the nanostructural parameters of the mineralized fibrillar collagen matrix, which affect bone quality, and develop a model linking these to increased fracture risk in glucocorticoid induced osteoporosis. Using a mouse model with an N-ethyl-N-nitrosourea (ENU)-induced corticotrophin releasing hormone promoter mutation (Crh(-120/+)) that developed hypercorticosteronaemia and osteoporosis, we utilized in situ mechanical testing with small angle X-ray diffraction, synchrotron micro-computed tomography and quantitative backscattered electron imaging to link altered nano- and microscale deformation mechanisms in the bone matrix to abnormal macroscopic mechanics. We measure the deformation of the mineralized collagen fibrils, and the nano-mechanical parameters including effective fibril modulus and fibril to tissue strain ratio. A significant reduction (51%) of fibril modulus was found in Crh(-120/+) mice. We also find a much larger fibril strain/tissue strain ratio in Crh(-120/+) mice (~1.5) compared to the wild-type mice (~0.5), indicative of a lowered mechanical competence at the nanoscale. Synchrotron microCT show a disruption of intracortical architecture, possibly linked to osteocytic osteolysis. These findings provide a clear quantitative demonstration of how bone quality changes increase macroscopic fragility in secondary osteoporosis.

  10. Changes in chemical composition of bone matrix in ovariectomized (OVX) rats detected by Raman spectroscopy and multivariate analysis

    NASA Astrophysics Data System (ADS)

    Oshima, Yusuke; Iimura, Tadahiro; Saitou, Takashi; Imamura, Takeshi

    2015-02-01

    Osteoporosis is a major bone disease that connotes the risk of fragility fractures resulting from alterations to bone quantity and/or quality to mechanical competence. Bone strength arises from both bone quantity and quality. Assessment of bone quality and bone quantity is important for prediction of fracture risk. In spite of the two factors contribute to maintain the bone strength, only one factor, bone mineral density is used to determine the bone strength in the current diagnosis of osteoporosis. On the other hand, there is no practical method to measure chemical composition of bone tissue including hydroxyapatite and collagen non-invasively. Raman spectroscopy is a powerful technique to analyze chemical composition and material properties of bone matrix non-invasively. Here we demonstrated Raman spectroscopic analysis of the bone matrix in osteoporosis model rat. Ovariectomized (OVX) rat was made and the decalcified sections of tibias were analyzed by a Raman microscope. In the results, Raman bands of typical collagen appeared in the obtained spectra. Although the typical mineral bands at 960 cm-1 (Phosphate) was absent due to decalcified processing, we found that Raman peak intensities of amide I and C-C stretching bands were significantly different between OVX and sham-operated specimens. These differences on the Raman spectra were statistically compared by multivariate analyses, principal component analysis (PCA) and liner discrimination analysis (LDA). Our analyses suggest that amide I and C-C stretching bands can be related to stability of bone matrix which reflects bone quality.

  11. Castor oil polymer induces bone formation with high matrix metalloproteinase-2 expression.

    PubMed

    Saran, Wallace Rocha; Chierice, Gilberto Orivaldo; da Silva, Raquel Assed Bezerra; de Queiroz, Alexandra Mussolino; Paula-Silva, Francisco Wanderley Garcia; da Silva, Léa Assed Bezerra

    2014-02-01

    The aim of this study was to evaluate the modulation of matrix metalloproteinase-2 (MMP-2) and -9 (MMP-9) expression in newly formed bone tissue at the interface between implants derived from castor oil (Ricinus communis) polymer and the tibia medullary canal. Forty-four rabbits were assigned to either Group 1 (n = 12; control) or Group 2 (n = 30), which had the tibial medullary canals reamed bilaterally and filled with polymer. CT scans showed no space between the material surface and the bone at the implant/bone marrow interface, and the density of the tissues at this interface was similar to the density measured of other regions of the bone. At 90 days postimplantation, the interface with the polymer presented a thick layer of newly formed bone tissue rich in osteocytes. This tissue exhibited ongoing maturation at 120 and 150 days postimplantation. Overall, bone remodeling process was accompanied by positive modulation of MMP-2 and low MMP-9 expression. Differently, in control group, the internal surface close to the medullary canal was lined by osteoblasts, followed by a bone tissue zone with few lacunae filled with osteocytes. Maturation of the tissue of the medullary internal surface occurred in the inner region, with the bone being nonlamellar.

  12. Effects of ultrasound on estradiol level, bone mineral density, bone biomechanics and matrix metalloproteinase-13 expression in ovariectomized rabbits

    PubMed Central

    XIA, LU; HE, HONGCHEN; GUO, HUA; QING, YUXI; HE, CHENG-QI

    2015-01-01

    The aim of the present study was to observe the effect of ultrasound (US) on estradiol level, bone mineral density (BMD), bone biomechanics and matrix metalloproteinase-13 (MMP-13) expression in ovariectomized (OVX) rabbits. A total of 28 virgin New Zealand white rabbits were randomly assigned into the following groups: Control (control group), ovariectomy (OVX group), ovariectomy with ultrasound therapy (US group) and ovariectomy with estrogen replacement therapy group (ERT group). At 8 weeks after ovariectomy, the US group received ultrasound treatment while the ERT group were orally treated with conjugated estrogens, and the control and OVX groups remained untreated. The estradiol level, BMD and bone biomechanics, cartilage histology and the MMP-13 expression were analyzed after the intervention. The results indicate that the US treatment increased estradiol level, BMD and bone biomechanical function. Furthermore, the US treatment appeared to improve the recovery of cartilage morphology and decreased the expression of MMP-13 in OVX models. Furthermore, the results suggest that 10 days of US therapy was sufficient to prevent the reduction of estradiol, BMD and bone biomechanical function, to protect osteoarthritis cartilage structure, and to reduce MMP-13 transcription and expression in OVX rabbits. Therefore, US treatment may be a potential treatment for postmenopausal osteoarthritis and osteoporosis. PMID:26622502

  13. How Osteoblasts Sense their Environment: Integrin-Extracellular Matrix Interactions and Mechanical Loading of Bone

    NASA Technical Reports Server (NTRS)

    Globus, Ruth K.; Dalton, Bonnie (Technical Monitor)

    2002-01-01

    Osteoblasts are the cells responsible for forming and replacing bone throughout life. We know that mechanical stimulation through weight-bearing at I gravity on Earth is needed to maintain healthy bone, and that osteoblasts play a critical role in that process. Over the last 9 years in my laboratory at NASA ARC, we have studied the regulation of osteoblast function by interactions between the extracellular matrix and die cell. Using a cell culture approach, we defined the repertoire of adhesion receptors, called integrins, which are expressed on the osteoblast surface, as well as specific extracellular matrix proteins, which are needed for cellular differentiation and survival. We are now extending these observations to determine if integrin signaling is involved in the skeletal responses to disuse and recovery from disuse using the rodent model of hindlimb unloading by tail suspension. Together, our cell culture and animal studies are providing new insight into the regulation of osteoblast function in bone.

  14. Long-term safety of antiresorptive treatment: bone material, matrix and mineralization aspects

    PubMed Central

    Misof, Barbara M; Fratzl-Zelman, Nadja; Paschalis, Eleftherios P; Roschger, Paul; Klaushofer, Klaus

    2015-01-01

    It is well established that long-term antiresorptive use is effective in the reduction of fracture risk in high bone turnover osteoporosis. Nevertheless, during recent years, concerns emerged that longer bone turnover reduction might favor the occurrence of fatigue fractures. However, the underlying mechanisms for both beneficial and suspected adverse effects are not fully understood yet. There is some evidence that their effects on the bone material characteristics have an important role. In principle, the composition and nanostructure of bone material, for example, collagen cross-links and mineral content and crystallinity, is highly dependent on tissue age. Bone turnover determines the age distribution of the bone structural units (BSUs) present in bone, which in turn is decisive for its intrinsic material properties. It is noteworthy that the effects of bone turnover reduction on bone material were observed to be dependent on the duration of the antiresorptive therapy. During the first 2–3 years, significant decreases in the heterogeneity of material properties such as mineralization of the BSUs have been observed. In the long term (5–10 years), the mineralization pattern reverts towards normal heterogeneity and degree of mineralization, with no signs of hypermineralization in the bone matrix. Nevertheless, it has been hypothesized that the occurrence of fatigue fractures (such as atypical femoral fractures) might be linked to a reduced ability of microdamage repair under antiresorptive therapy. The present article examines results from clinical studies after antiresorptive, in particular long-term, therapy with the aforementioned potentially positive or negative effects on bone material. PMID:25709811

  15. Demineralized dentin matrix combined with recombinant human bone morphogenetic protein-2 in rabbit calvarial defects

    PubMed Central

    2016-01-01

    Objectives The aim of this study was to compare the osteogenic effects of demineralized dentin matrix (DDM) combined with recombinant human bone morphogenetic protein-2 (rhBMP-2) in rabbit calvarial defects with DDM and anorganic bovine bone (ABB) combined with rhBMP-2. Materials and Methods Four round defects with 8-mm diameters were created in each rabbit calvaria. Each defect was treated with one of the following: 1) DDM, 2) ABB/rhBMP-2, or 3) DDM/rhBMP-2. The rhBMP-2 was combined with DDM and ABB according to a stepwise dry and dip lyophilizing protocol. Histological and microcomputed tomography (µCT) analyses were performed to measure the amount of bone formation and bone volume after 2- and 8-week healing intervals. Results Upon histological observation at two weeks, the DDM and ABB/rhBMP-2 groups showed osteoconductive bone formation, while the DDM/rhBMP-2 group showed osteoconductive and osteoinductive bone formation. New bone formation was higher in DDM/rhBMP-2, DDM and ABB decreasing order. The amounts of bone formation were very similar at two weeks; however, at eight weeks, the DDM/rhBMP-2 group showed a two-fold greater amount of bone formation compared to the DDM and ABB/rhBMP-2 groups. The µCT analysis showed markedly increased bone volume in the DDM/rhBMP-2 group at eight weeks compared with that of the DDM group. Notably, there was a slight decrease in bone volume in the ABB/rhBMP-2 group at eight weeks. There were no significant differences among the DDM, ABB/rhBMP-2, and DDM/rhBMP-2 groups at two or eight weeks. Conclusion Within the limitations of this study, DDM appears to be a suitable carrier for rhBMP-2 in orthotopic sites. PMID:27162749

  16. Bone-related matrix proteins expression in vitro and in vivo by marrow stromal cell line.

    PubMed

    Benayahu, D; Gurevitz, O A; Shamay, A

    1994-10-01

    MBA-1, a bone marrow stroma-derived cell line, was transplanted in an ectopic site and formed endochondral bone. The ossicle developed through stages of cell proliferation, differentiated into a zone of hypertrophy and formed a chondroid-like area which further developed to primary mineralized bone. We explored the expression of various matrix proteins by MBA-1 cells in vitro and in the ossicle formed in vivo. MBA-1 cells constitutively expressed mRNAs encoding for collagen I, non-collagenous proteins and alkaline phosphatase. RNA extracted from the ossicle formed by these cells was expressed in a different pattern. The in vivo maturation of MBA-1 cells was accompanied by low expression of mRNA for procollagen alpha 2(I) and a marked increase in osteonectin and osteopontin mRNA levels. Thus, the ability to follow expression of these genes through bone formation in vivo has been demonstrated. PMID:9437244

  17. Matrix extracellular phosphoglycoprotein (MEPE) is a new bone renal hormone and vascularization modulator.

    PubMed

    David, Valentin; Martin, Aline; Hedge, Anne-Marie; Rowe, Peter S N

    2009-09-01

    Increased matrix extracellular phosphoglycoprotein (MEPE) expression occurs in several phosphate and bone-mineral metabolic disorders. To resolve whether MEPE plays a role, we created a murine model overexpressing MEPE protein (MEPE tgn) in bone. MEPE tgn mice displayed a growth and mineralization defect with altered bone-renal vascularization that persisted to adulthood. The growth mineralization defect was due to a decrease in bone remodeling, and MEPE tgn mice were resistant to diet-induced renal calcification. MEPE protein-derived urinary ASARM peptides and reduced urinary Ca X PO4 product mediated the suppressed renal calcification. Osteoblastic cells displayed reduced activity but normal differentiation. Osteoclastic precursors were unable to differentiate in the presence of osteoblasts. In the kidney, NPT2a up-regulation induced an increase in phosphate renal reabsorption, leading to hyperphosphatemia. We conclude MEPE and MEPE-phosphate-regulating gene with homologies to endopeptidases on the X chromosome (MEPE-PHEX) interactions are components to an age-diet-dependent pathway that regulates bone turnover and mineralization and suppresses renal calcification. This novel pathway also modulates bone-renal vascularization and bone turnover.

  18. Tendon Reattachment to Bone in an Ovine Tendon Defect Model of Retraction Using Allogenic and Xenogenic Demineralised Bone Matrix Incorporated with Mesenchymal Stem Cells

    PubMed Central

    2016-01-01

    Background Tendon-bone healing following rotator cuff repairs is mainly impaired by poor tissue quality. Demineralised bone matrix promotes healing of the tendon-bone interface but its role in the treatment of tendon tears with retraction has not been investigated. We hypothesized that cortical demineralised bone matrix used with minimally manipulated mesenchymal stem cells will result in improved function and restoration of the tendon-bone interface with no difference between xenogenic and allogenic scaffolds. Materials and Methods In an ovine model, the patellar tendon was detached from the tibial tuberosity and a complete distal tendon transverse defect measuring 1 cm was created. Suture anchors were used to reattach the tendon and xenogenic demineralised bone matrix + minimally manipulated mesenchymal stem cells (n = 5), or allogenic demineralised bone matrix + minimally manipulated mesenchymal stem cells (n = 5) were used to bridge the defect. Graft incorporation into the tendon and its effect on regeneration of the enthesis was assessed using histomorphometry. Force plate analysis was used to assess functional recovery. Results Compared to the xenograft, the allograft was associated with significantly higher functional weight bearing at 6 (P = 0.047), 9 (P = 0.028), and 12 weeks (P = 0.009). In the allogenic group this was accompanied by greater remodeling of the demineralised bone matrix into tendon-like tissue in the region of the defect (p = 0.015), and a more direct type of enthesis characterized by significantly more fibrocartilage (p = 0.039). No failures of tendon-bone healing were noted in either group. Conclusion Demineralised bone matrix used with minimally manipulated mesenchymal stem cells promotes healing of the tendon-bone interface in an ovine model of acute tendon retraction, with superior mechanical and histological results associated with use of an allograft. PMID:27606597

  19. Age-dependent changes in matrix composition and organization at the ligament-to-bone insertion.

    PubMed

    Wang, I-Ning E; Mitroo, Siddarth; Chen, Faye H; Lu, Helen H; Doty, Stephen B

    2006-08-01

    Injuries to the anterior cruciate ligament (ACL) often occur at the ligament-to-bone insertion site; thus, an in-depth understanding of the native insertion is critical in identifying the etiology of failure and devising optimal treatment protocols for ACL injuries. The objective of this study is to conduct a systematic characterization of the ACL-to-bone interface, focusing on structural and compositional changes as a function of age. Using a bovine model, three age groups were studied: Neonatal (1-7 days old), Immature (2-6 months old), and Mature (2-5 years old). The distribution of types I, II, X collagen, decorin, cartilage oligomeric matrix protein (COMP), glycosaminoglycan (GAG), alkaline phosphatase (ALP) activity, and minerals at the ACL-to-bone insertion were examined. Additionally, cell aspect ratio, size, and distribution across the insertion were quantified. The ACL-to-bone insertion is divided into four regions: ligament, nonmineralized interface, mineralized interface, and bone. Both region-dependent and age-dependent structural and compositional changes at the insertion site were observed in this study. The interface in the skeletally immature group resembled articular cartilage, while the adult interface was similar to fibrocartilaginous tissue. Age-dependent changes in extracellular matrix composition (type X collagen, sulfated glycosaminoglycan), cellularity, ALP activity, and mineral distribution were also found. Marked differences in collagen fiber orientation between the femoral and tibial insertions were observed, and these differences became more pronounced with age.

  20. Isolation of human mesenchymal stem cells and their cultivation on the porous bone matrix.

    PubMed

    Rodríguez-Fuentes, Nayeli; Reynoso-Ducoing, Olivia; Rodríguez-Hernández, Ana; Ambrosio-Hernández, Javier R; Piña-Barba, Maria C; Zepeda-Rodríguez, Armando; Cerbón-Cervantes, Marco A; Tapia-Ramírez, José; Alcantara-Quintana, Luz E

    2015-02-09

    Mesenchymal stem cells (MSCs) have a differentiation potential towards osteoblastic lineage when they are stimulated with soluble factors or specific biomaterials. This work presents a novel option for the delivery of MSCs from human amniotic membrane (AM-hMSCs) that employs bovine bone matrix Nukbone (NKB) as a scaffold. Thus, the application of MSCs in repair and tissue regeneration processes depends principally on the efficient implementation of the techniques for placing these cells in a host tissue. For this reason, the design of biomaterials and cellular scaffolds has gained importance in recent years because the topographical characteristics of the selected scaffold must ensure adhesion, proliferation and differentiation into the desired cell lineage in the microenvironment of the injured tissue. This option for the delivery of MSCs from human amniotic membrane (AM-hMSCs) employs bovine bone matrix as a cellular scaffold and is an efficient culture technique because the cells respond to the topographic characteristics of the bovine bone matrix Nukbone (NKB), i.e., spreading on the surface, macroporous covering and colonizing the depth of the biomaterial, after the cell isolation process. We present the procedure for isolating and culturing MSCs on a bovine matrix.

  1. Isolation of Human Mesenchymal Stem Cells and their Cultivation on the Porous Bone Matrix

    PubMed Central

    Rodríguez-Fuentes, Nayeli; Reynoso-Ducoing, Olivia; Rodríguez-Hernández, Ana; Ambrosio-Hernández, Javier R.; Piña-Barba, Maria C.; Zepeda-Rodríguez, Armando; Cerbón-Cervantes, Marco A.; Tapia-Ramírez, José; Alcantara-Quintana, Luz E.

    2015-01-01

    Mesenchymal stem cells (MSCs) have a differentiation potential towards osteoblastic lineage when they are stimulated with soluble factors or specific biomaterials. This work presents a novel option for the delivery of MSCs from human amniotic membrane (AM-hMSCs) that employs bovine bone matrix Nukbone (NKB) as a scaffold. Thus, the application of MSCs in repair and tissue regeneration processes depends principally on the efficient implementation of the techniques for placing these cells in a host tissue. For this reason, the design of biomaterials and cellular scaffolds has gained importance in recent years because the topographical characteristics of the selected scaffold must ensure adhesion, proliferation and differentiation into the desired cell lineage in the microenvironment of the injured tissue. This option for the delivery of MSCs from human amniotic membrane (AM-hMSCs) employs bovine bone matrix as a cellular scaffold and is an efficient culture technique because the cells respond to the topographic characteristics of the bovine bone matrix Nukbone (NKB), i.e., spreading on the surface, macroporous covering and colonizing the depth of the biomaterial, after the cell isolation process. We present the procedure for isolating and culturing MSCs on a bovine matrix. PMID:25742362

  2. Histochemical and morphological studies on a new type of acellular cartilage.

    PubMed

    Junqueira, L C; Toledo, O M; Montes, G S

    1983-01-01

    A new type of cartilage was found participating in a valve-like system inside the conus arteriosus of the fresh water sting ray, Potamotrygon sp.. This cartilage possesses no chondrocytes and its matrix is perforated by vascular channels that ramify dendritically forming canaliculi. The acellular cartilage does not possess perichondrium but, rather, it is attached to a basement membrane-like structure. The cartilaginous matrix contains collagen fibrils that strongly interact with the chondroitin sulfate of the ground substance. The histochemical and biochemical findings suggest that not all of the glycosaminoglycans present in the acellular cartilage are bound to protein cores to form proteoglycans. PMID:6407464

  3. Fibular Allograft and Demineralized Bone Matrix for the Treatment of Slipped Capital Femoral Epiphysis.

    PubMed

    Murray, Travis; Morscher, Melanie A; Krahe, Amy M; Adamczyk, Mark J; Weiner, Dennis S

    2016-05-01

    Previous studies documented the use of fibular allograft in the treatment of slipped capital femoral epiphysis (SCFE) with bone graft epiphysiodesis (BGE). This study describes the results of using a 10-mm diameter premilled fibular allograft packed with demineralized bone matrix placed across the physis in an open surgical approach under image intensification. A review identified 45 cases of BGE using fibular allograft and demineralized bone matrix in 34 patients with a diagnosis of SCFE performed by a single surgeon during an 8-year period. Thirty-four cases (25 patients) had at least 1 year of follow-up and were included in the study. Medical records were reviewed for complications, subsequent surgeries, and time to physeal closure. Of the 34 cases included, there were no cases of acute chondrolysis. Complications included 1 case of bone graft extrusion that required surgical replacement and 1 re-slip requiring surgical stabilization. Five cases of avascular necrosis (AVN) were encountered (1 unstable slip with total head AVN, and 4 stable slips with 3 total head and 1 partial head AVN). In 1 patient, small loose bony fragments were noted on postoperative radiographs that appeared outside of the articular surface of the hip and were asymptomatic. Two patients encountered wound healing issues that resolved with appropriate wound care. In light of the occurrence of AVN in stable cases, BGE with autogenous corticocancellous graft is preferable to BGE with autologous fibular graft for the treatment of SCFE. [Orthopedics. 2016; 39(3):e519-e525.].

  4. Spaceflight has compartment- and gene-specific effects on mRNA levels for bone matrix proteins in rat femur

    NASA Technical Reports Server (NTRS)

    Evans, G. L.; Morey-Holton, E.; Turner, R. T.

    1998-01-01

    In the present study, we evaluated the possibility that the abnormal bone matrix produced during spaceflight may be associated with reduced expression of bone matrix protein genes. To test this possibility, we investigated the effects of a 14-day spaceflight (SLS-2 experiment) on steady-state mRNA levels for glyceraldehyde-3-phosphate dehydrogenase (GAPDH), osteocalcin, osteonectin, and prepro-alpha(1) subunit of type I collagen in the major bone compartments of rat femur. There were pronounced site-specific differences in the steady-state levels of expression of the mRNAs for the three bone matrix proteins and GAPDH in normal weight-bearing rats, and these relationships were altered after spaceflight. Specifically, spaceflight resulted in decreases in mRNA levels for GAPDH (decreased in proximal metaphysis), osteocalcin (decreased in proximal metaphysis), osteonectin (decreased in proximal and distal metaphysis), and collagen (decreased in proximal and distal metaphysis) compared with ground controls. There were no changes in mRNA levels for matrix proteins or GAPDH in the shaft and distal epiphysis. These results demonstrate that spaceflight leads to site- and gene-specific decreases in mRNA levels for bone matrix proteins. These findings are consistent with the hypothesis that spaceflight-induced decreases in bone formation are caused by concomitant decreases in expression of genes for bone matrix proteins.

  5. Age- and gender-related changes in the distribution of osteocalcin in the extracellular matrix of normal male and female bone. Possible involvement of osteocalcin in bone remodeling.

    PubMed Central

    Ingram, R T; Park, Y K; Clarke, B L; Fitzpatrick, L A

    1994-01-01

    With increasing age, bone undergoes changes in remodeling that ultimately compromise the structural integrity of the skeleton. The presence of osteocalcin in bone matrix may alter bone remodeling by promoting osteoclast activity. Whether age- and/or gender-related differences exist in the distribution of osteocalcin within individual bone remodeling units is not known. In this study, we determined the immunohistochemical distribution of osteocalcin in the extracellular matrix of iliac crest bone biopsies obtained from normal male and female volunteers, 20-80 yr old. Four different distribution patterns of osteocalcin within individual osteons were arbitrarily defined as types I, II, III, or IV. The frequency of appearance of each osteon type was determined as a percent of the total osteons per histologic section. The proportion of osteons that stained homogeneously throughout the concentric lamellae (type I) decreased in females and males with increasing age. The proportion of osteons that lack osteocalcin in the matrix immediately adjacent to Haversian canals (type III) increased in females and males with age. Osteons staining intensely in the matrix adjacent to Haversian canals (type II) increased in females and was unchanged in aging males. Osteons that contained osteocalcin-positive resting lines (type IV) increased in bone obtained from males with increasing age but were unchanged in females. Sections of bone immunostained for osteopontin (SPP-I), osteonectin, and decorin did not reveal multiple patterns or alterations in staining with gender or increasing age. We suggest that the morphology of individual bone remodeling units is heterogeneous and the particular morphologic pattern of osteocalcin distribution changes with age and gender. These results suggest that differences in the distribution of osteocalcin in bone matrix may be responsible, in part, for the altered remodeling of bone associated with gender and aging. Images PMID:8132785

  6. Angiopoietin-1 peptide QHREDGS promotes osteoblast differentiation, bone matrix deposition and mineralization on biomedical materials†

    PubMed Central

    Feric, Nicole; Cheng, Calvin C.H.; Goh, M. Cynthia; Dudnyk, Vyacheslav; Di Tizio, Val; Radisic, Milica

    2014-01-01

    Bone loss occurs as a consequence of a variety of diseases as well as from traumatic injuries, and often requires therapeutic intervention. Strategies for repairing and replacing damaged and/or lost bone tissue include the use of biomaterials and medical implant devices with and without osteoinductive coatings. The soluble growth factor angiopoietin-1 (Ang-1) has been found to promote cell adhesion and survival in a range of cell types including cardiac myocytes, endothelial cells and fibroblasts through an integrin-dependent mechanism. Furthermore, the short sequence QHREDGS has been identified as the integrin-binding sequence of Ang-1 and as a synthetic peptide has been found to possess similar integrin-dependent effects as Ang-1 in the aforementioned cell types. Integrins have been implicated in osteoblast differentiation and bone mineralization, processes critical to bone regeneration. By binding integrins on the osteoblast surface, QHREDGS could promote cell survival and adhesion, as well as conceivably osteoblast differentiation and bone mineralization. Here we immobilized QHREDGS onto polyacrylate (PA)-coated titanium (Ti) plates and polyethylene glycol (PEG) hydrogels. The osteoblast differentiation marker, alkaline phosphatase, peaked in activity 4-12 days earlier on the QHREDGS-immobilized PA-coated Ti plates than on the unimmobilized, DGQESHR (scrambled)- and RGDS-immobilized surfaces. Significantly more bone matrix was deposited on the QHREDGS-immobilized Ti surface than on the other surfaces as determined by atomic force microscopy. The QHREDGS-immobilized hydrogels also had a significantly higher mineral-to-matrix (M/M) ratio determined by Fourier transform infrared spectroscopy. Alizarin Red S and von Kossa staining and quantification, and environmental scanning electron microscopy showed that while both the QHREDGS- and RGDS-immobilized surfaces had extensive mineralization relative to the unimmobilized and DGQESHR-immobilized surfaces, the

  7. Biomineralization of a Self-Assembled Extracellular Matrix for Bone Tissue Engineering

    SciTech Connect

    Yizhi, M.; Yi-Xian, Q; DiMasi, E; Xiaolan, B; Rafailovich, M; Pernodet, N

    2009-01-01

    Understanding how biomineralization occurs in the extracellular matrix (ECM) of bone cells is crucial to the understanding of bone formation and the development of a successfully engineered bone tissue scaffold. It is still unclear how ECM mechanical properties affect protein-mineral interactions in early stages of bone mineralization. We investigated the longitudinal mineralization properties of MC3T3-E1 cells and the elastic modulus of their ECM using shear modulation force microscopy, synchrotron grazing incidence X-ray diffraction (GIXD), scanning electron microscopy, energy dispersive X-ray spectroscopy, and confocal laser scanning microscopy (CLSM). The elastic modulus of the ECM fibers underwent significant changes for the mineralizing cells, which were not observed in the nonmineralizing cells. On substrates conducive to ECM network production, the elastic modulus of mineralizing cells increased at time points corresponding to mineral production, whereas that of the nonmineralizing cells did not vary over time. The presence of hydroxyapatite in mineralizing cells and the absence thereof in the nonmineralizing ones were confirmed by GIXD, and CLSM showed that a restructuring of actin occurred only for mineral-producing cells. These results show that the correct and complete development of the ECM network is required for osteoblasts to mineralize. This in turn requires a suitably prepared synthetic substrate for bone development to succeed in vitro.

  8. Connective tissue-bone onlay graft with enamel matrix derivative for treatment of gingival recession: a case report.

    PubMed

    Nozawa, Takeshi; Sugiyama, Takahiko; Satoh, Tohru; Tanaka, Koji; Enomoto, Hiroaki; Ito, Koichi

    2002-12-01

    We describe a case of gingival recession in which root coverage and coronal bone regrowth were achieved after treatment with a connective tissue-bone graft and enamel matrix derivative. The connective tissue-bone graft was harvested from a maxillary edentulous area and then curved to fit the root surfaces of the maxillary left central and lateral incisors. Enamel matrix derivative was applied to the root surfaces, and the connective tissue-bone graft was fixed to the interdental bone by a titanium screw. Six months later, the exposed roots were covered with thick gingiva, and coronal regrowth of thick bone was evident at reentry surgery. This technique is useful for esthetic restoration placement with an intracrevicular margin on teeth with a thin, receding gingiva.

  9. Two-Stage Revision Anterior Cruciate Ligament Reconstruction: Bone Grafting Technique Using an Allograft Bone Matrix.

    PubMed

    Chahla, Jorge; Dean, Chase S; Cram, Tyler R; Civitarese, David; O'Brien, Luke; Moulton, Samuel G; LaPrade, Robert F

    2016-02-01

    Outcomes of primary anterior cruciate ligament (ACL) reconstruction have been reported to be far superior to those of revision reconstruction. However, as the incidence of ACL reconstruction is rapidly increasing, so is the number of failures. The subsequent need for revision ACL reconstruction is estimated to occur in up to 13,000 patients each year in the United States. Revision ACL reconstruction can be performed in one or two stages. A two-stage approach is recommended in cases of improper placement of the original tunnels or in cases of unacceptable tunnel enlargement. The aim of this study was to describe the technique for allograft ACL tunnel bone grafting in patients requiring a two-stage revision ACL reconstruction. PMID:27274452

  10. Two-Stage Revision Anterior Cruciate Ligament Reconstruction: Bone Grafting Technique Using an Allograft Bone Matrix.

    PubMed

    Chahla, Jorge; Dean, Chase S; Cram, Tyler R; Civitarese, David; O'Brien, Luke; Moulton, Samuel G; LaPrade, Robert F

    2016-02-01

    Outcomes of primary anterior cruciate ligament (ACL) reconstruction have been reported to be far superior to those of revision reconstruction. However, as the incidence of ACL reconstruction is rapidly increasing, so is the number of failures. The subsequent need for revision ACL reconstruction is estimated to occur in up to 13,000 patients each year in the United States. Revision ACL reconstruction can be performed in one or two stages. A two-stage approach is recommended in cases of improper placement of the original tunnels or in cases of unacceptable tunnel enlargement. The aim of this study was to describe the technique for allograft ACL tunnel bone grafting in patients requiring a two-stage revision ACL reconstruction.

  11. Angiogenic response induced by acellular brain scaffolds grafted onto the chick embryo chorioallantoic membrane.

    PubMed

    Ribatti, Domenico; Conconi, Maria Teresa; Nico, Beatrice; Baiguera, Silvia; Corsi, Patrizia; Parnigotto, Pier Paolo; Nussdorfer, Gastone G

    2003-10-31

    The repair and regeneration of injured tissues and organs depend on the re-establishment of the blood flow needed for cellular infiltration and metabolic support. Among the various materials used in tissue reconstruction, acellular scaffolds have recently been utilized. In this study, we investigated the angiogenic response induced by acellular brain scaffolds implanted in vivo onto the chick embryo chorioallantoic membrane (CAM), a useful model for such investigations. The results show that acellular brain scaffolds are able to induce a strong angiogenic response, comparable to that of fibroblast growth factor-2 (FGF-2), a well known angiogenic cytokine. The response may be considered dependent on a direct angiogenic effect exerted by the scaffold, because no inflammatory infiltrate was detectable in CAM's mesenchyme beneath the implant. Acellular brain scaffolds might induce the release of endogenous angiogenic factors, such as FGF-2 and vascular endothelial growth factor (VEGF) released from the extracellular matrix of the developing CAM. In addition, the angiogenic response may depend, in part, also on the presence in the acellular matrix of transforming growth factor beta 1 (TGFbeta1).

  12. Acellular pertussis vaccines in China.

    PubMed

    Wang, Lichan; Lei, Dianliang; Zhang, Shumin

    2012-11-26

    In China, whole-cell pertussis (Pw) vaccines were produced in the early 1960s and acellular pertussis (Pa) vaccines were introduced in 1995. Pa vaccines have now almost completely replaced Pw vaccines in the national immunization program. To strengthen the regulation of vaccines used in China, a vaccine lot release system was established in 2001 and Pa vaccines have been included in the system since 2006. This paper mainly described the current status of production and the quality control measures in place for Pa vaccines; and analyses quality control test data accumulated between 2006 and 2010.

  13. Identification of full-length dentin matrix protein 1 in dentin and bone.

    PubMed

    Huang, Bingzhen; Maciejewska, Izabela; Sun, Yao; Peng, Tao; Qin, Disheng; Lu, Yongbo; Bonewald, Lynda; Butler, William T; Feng, Jian; Qin, Chunlin

    2008-05-01

    Dentin matrix protein 1 (DMP1) has been identified in the extracellular matrix (ECM) of dentin and bone as the processed NH(2)-terminal and COOH-terminal fragment. However, the full-length form of DMP1 has not been identified in these tissues. The focus of this investigation was to search for the intact full-length DMP1 in dentin and bone. We used two types of anti-DMP1 antibodies to identify DMP1: one type specifically recognizes the NH(2)-terminal region and the other type is only reactive to the COOH-terminal region of the DMP1 amino acid sequence. An approximately 105-kDa protein, extracted from the ECM of rat dentin and bone, was recognized by both types of antibodies; and the migration rate of this protein was identical to the recombinant mouse full-length DMP1 made in eukaryotic cells. We concluded that this approximately 105-kDa protein is the full-length form of DMP1, which is considerably less abundant than its processed fragments in the ECM of dentin and bone. We also detected the full-length form of DMP1 and its processed fragments in the extract of dental pulp/odontoblast complex dissected from rat teeth. In addition, immunofluorescence analysis showed that in MC3T3-E1 cells the NH(2)-terminal and COOH-terminal fragments of DMP1 are distributed differently. Our findings indicate that the majority of DMP1 must be cleaved within the cells that synthesize it and that minor amounts of uncleaved DMP1 molecules are secreted into the ECM of dentin and bone.

  14. Osteoclast Precursor Interaction with Bone Matrix Induces Osteoclast Formation Directly by an Interleukin-1-mediated Autocrine Mechanism*

    PubMed Central

    Yao, Zhenqiang; Xing, Lianping; Qin, Chunlin; Schwarz, Edward M.; Boyce, Brendan F.

    2008-01-01

    Interleukin-1 (IL-1) and tumor necrosis factor (TNF) mediate bone resorption in a variety of diseases affecting bone. Like TNF, IL-1 is secreted by osteoclast precursors (OCPs), but unlike TNF, it does not induce osteoclast formation directly from OCPs in vitro. TNF induces IL-1 expression and activates c-Fos, a transcription factor required in OCPs for osteoclast formation. Here, we examined whether IL-1 can induce osteoclast formation directly from OCPs overexpressing c-Fos and whether interaction with bone matrix affects OCP cytokine expression. We infected OCPs with c-Fos or green fluorescent protein retrovirus, cultured them with macrophage colony-stimulating factor and IL-1 on bone slices or plastic dishes, and assessed osteoclast and resorption pit formation and expression of IL-1 by OCPs. We used a Transwell assay to determine whether OCPs secrete IL-1 when they interact with bone matrix. IL-1 induced osteoclast formation directly from c-Fos-expressing OCPs on plastic. c-Fos-expressing OCPs formed osteoclasts spontaneously on bone slices without addition of cytokines. OCPs on bone secreted IL-1, which induced osteoclast formation from c-Fos-expressing OCPs in the lower Transwell dishes. The bone matrix proteins dentin sialoprotein and osteopontin, but not transforming growth factor-β, stimulated OCP expression of IL-1 and induced c-Fos-expressing OCP differentiation into osteoclasts. Osteoclasts eroding inflamed joints have higher c-Fos expression compared with osteoclasts inside bone. We conclude that OCPs expressing c-Fos may induce their differentiation directly into osteoclasts by an autocrine mechanism in which they produce IL-1 through interaction with bone matrix. TNF could induce c-Fos expression in OCPs at sites of inflammation in bone to promote this autocrine mechanism and thus amplify bone loss. PMID:18250170

  15. Localization of malachite green positive lipids in the matrix of bone nodule formed in vitro.

    PubMed

    Nefussi, J R; Septier, D; Sautier, J M; Forest, N; Goldberg, M

    1992-03-01

    An electron histochemical study was carried out on bone nodules formed in vitro in collagenase-released calvarial cells in order to visualize the lipid components of the extracellular matrix (EM). The malachite green aldehyde fixative technique, which allows both preservation and staining of some phospholipids of the extracellular matrix, was used. Controls were performed on sections demineralized, and then submitted to lipid extraction with a chloroformmethanol mixture (2/1 v/v) and to glycosaminoglycans digestion with 0.5% bovine testicular hyaluronidase to verify specificity for lipid staining. This allowed us to visualize the lipids (1) in the osteoid as granules associated to ribbon-like structures connected to the collagen fibers, (2) as electrondense deposits seen as dots on the outer surface membrane of the matrix vesicles, and (3) in the mineralized matrix as roundish patches formed of needle-shaped materials and at the mineralization front as individual ones. This study demonstrated that at the EM level, the lipids are present in the osteoid at locations very similar to what have been observed for the glycosaminoglycans, and in the mineralized matrix as components of the crystal ghosts.

  16. Production of an osteoinductive demineralised bone matrix powder without the use of organic solvents.

    PubMed

    Eagle, M J; Rooney, P; Kearney, J N

    2015-09-01

    Demineralised bone matrix (DBM) is produced by grinding cortical bone into a powder, sieving the powder to obtain a desired size range and then demineralising the powder using acid. Protocols for the production of DBM powder have been published since 1965 and the powder can be used in lyophilised form or it can be mixed with a carrier to produce a paste or putty. The powder is generally produced from cortical bone which has been processed to remove blood, bone marrow and bone marrow components, including fat. Removal of fat is accomplished by incorporating incubation in an organic solvent, often chloroform, chloroform/methanol or acetone. The use of organic solvents in a clean room environment in a human tissue bank is problematic and involves operator exposure and the potential for the solvent to be trapped in air filters or recirculated throughout the clean room suite. Consequently, in this study, we have developed a cortical bone washing step which removes fat/lipid without the use of an organic solvent. Bone was prepared from six femoral shafts from three donors by dissecting soft tissue and bisecting the shaft, the shafts were then cut into ~9-10 cm lengths. These struts were then taken through a series of hot water washes at 56-59 °C, centrifugation and decontamination steps. Washed cortical struts were then lyophilised before being ground with a compressed air milling machine. The ground bone was sieved, demineralised, freeze-dried and terminally sterilised with a target dose of 25 kGy gamma irradiation. The DBM powder was evaluated for residual calcium content, in vitro cytotoxicity and osteoinductivity by implantation into the muscle of an athymic mouse. Data indicated that in addition to removing in excess of 97% DNA and extractable soluble protein, the washing protocol reduced lipid 10,000-fold. The processed bone was easily ground without clogging the grinder; the sterilised DBM powder was not cytotoxic but was osteoinductive in the animal model

  17. [Aplication of demineralized human bone matrix in the surgical dental fusion treatment. Report of a case].

    PubMed

    Mora-Rincones, Oscar A; Corona-Rodríguez, Julio C; Díaz-Carvajal, Alvaro L; Franco-Carrero, Isabel C

    2008-06-01

    The purpose of this work is to present a surgical alternative in the treatment of the dental fusions through the placement of demineralized human bone matrix (DHBM) (Grafton Putty)*, immediately after the separation and extraction of the fused tooth to the permanent one. The dental fusion is a dental anomaly of union, that consists in the union of two dental germs during development. It could happen at any of the dental germ evolution stages from the dental sheet or from more advanced processes of differentiation. For the clinical treatment, an allograft of DHBM with osteoinductive and osteoconductive properties was used. This had several factors of bone growth, it allowed the gradual growth of a new bone that helped to correct the bone defects post-extraction and to cover the exposed distal wall of the remaining permanent tooth. The clinic evaluation and the periapical and panoramic radiographies images were used for the clinical control. It can be concluded that the surgical separation and the extraction of the tooth with less anatomical likeness to the contralateral and the placement of the DHBM, represent a surgical treatment alternative of the dental fusion.

  18. Extracellular matrix-inspired growth factor delivery systems for bone regeneration

    SciTech Connect

    Martino, Mikaël M.; Briquez, Priscilla S.; Maruyama, Kenta; Hubbell, Jeffrey A.

    2015-04-17

    Growth factors are very promising molecules to enhance bone regeneration. However, their translation to clinical use has been seriously limited, facing issues related to safety and cost-effectiveness. These problems derive from the vastly supra-physiological doses of growth factor used without optimized delivery systems. Therefore, these issues have motivated the development of new delivery systems allowing better control of the spatio-temporal release and signaling of growth factors. Because the extracellular matrix (ECM) naturally plays a fundamental role in coordinating growth factor activity in vivo, a number of novel delivery systems have been inspired by the growth factor regulatory function of the ECM. After introducing the role of growth factors during the bone regeneration process, this review exposes different issues that growth factor-based therapies have encountered in the clinic and highlights recent delivery approaches based on the natural interaction between growth factor and the ECM.

  19. Extracellular matrix-inspired growth factor delivery systems for bone regeneration.

    PubMed

    Martino, Mikaël M; Briquez, Priscilla S; Maruyama, Kenta; Hubbell, Jeffrey A

    2015-11-01

    Growth factors are very promising molecules to enhance bone regeneration. However, their translation to clinical use has been seriously limited, facing issues related to safety and cost-effectiveness. These problems derive from the vastly supra-physiological doses of growth factor used without optimized delivery systems. Therefore, these issues have motivated the development of new delivery systems allowing better control of the spatiotemporal release and signaling of growth factors. Because the extracellular matrix (ECM) naturally plays a fundamental role in coordinating growth factor activity in vivo, a number of novel delivery systems have been inspired by the growth factor regulatory function of the ECM. After introducing the role of growth factors during the bone regeneration process, this review exposes different issues that growth factor-based therapies have encountered in the clinic and highlights recent delivery approaches based on the natural interaction between growth factor and the ECM.

  20. Interleukin-1 and tumor necrosis factor-alpha induce collagenolysis and bone resorption by regulation of matrix metalloproteinase-2 in mouse calvarial bone cells.

    PubMed

    Kang, Bong-Seok; Park, Young-Guk; Cho, Jin-Young; Kim, June-Ki; Lee, Tae-Kyun; Kim, Dong-Wook; Gu, Yeun-Hwa; Suzuki, Ikukatsu; Chang, Young-Chae; Kim, Cheorl-Ho

    2003-08-01

    Interleukin-1beta (IL-1beta) and tumor necrosis factor-alpha (TNF-alpha) greatly induces osteoclast formation and stimulates bone resorption of mouse calvaria in culture. We examined the effects of the two cytokines on the collagenolysis and bone resorption by induction of matrix metalloproteinases (MMPs). The cells were analyzed using zymographic analysis. It was shown that the mouse calvarial osteoblasts constitutively synthesize progelatinase-A (MMP-2). Interleukin-1beta markedly enhanced the messenger RNAs (mRNAs) expression of MMP-2 (gelatinase A), but slightly MMP-9 (gelatinase B), which associated with increases in bone matrix degradation. Both pro- and active-forms of MMP-2 were detected in the conditioned medium collected from calvarial cultures, and IL-1beta markedly stimulated both pro- and active-forms of the MMP-2. The expression of MMP-2 mRNAs could be detected, and they were markedly enhanced by IL-1beta on days 1 and 2. These results demonstrate that the potency of induction of MMP-2 by IL-1beta and TNF-alpha is closely linked to the respective bone-resorbing activity, suggesting that MMP-2-dependent degradation of bone matrix plays a key role in bone resorption induced by these cytokines. On the other hand, when the mouse osteoblasts were stimulated with parathyroid hormone, 1,25(OH)2D3, mononuclear cell conditioned medium (MCM) and IL-1 as bone resorption agents, collagenolysis was increased by producing the active gelatinase. Interleukin-1 in stimulating bone resorption was examined using fetal mouse long bone organ culture. Interleukin-1 stimulated bone resorption and produced marked resorption when present simultaneously. Furthermore, treatment of indomethacin and dexamethasone clearly abolished the responses of IL-1alpha and IL-1beta.

  1. Granule size-dependent bone regenerative capacity of octacalcium phosphate in collagen matrix.

    PubMed

    Tanuma, Yuji; Anada, Takahisa; Honda, Yoshitomo; Kawai, Tadashi; Kamakura, Shinji; Echigo, Seishi; Suzuki, Osamu

    2012-03-01

    The present study was designed to determine whether the osteoconductivity of octacalcium phosphate-collagen (OCP/Col) composite can be improved by controlling the granule size of OCP. The granules of synthetic OCP, with diameters in the range of 53 to 300, 300 to 500, and 500 to 1000 μm, were used as an inorganic source of composite materials mixed with atelo-Col. After vacuum dehydrothemal treatment, OCP/Col disks were implanted into critical-sized calvaria defects in Wistar rats for 4, 8, and 12 weeks and examined radiographically, histologically, histomorphometrically, and histochemically. The materials were characterized according to mercury intrusion porosimetry and scanning electron microscopy. X-ray diffraction was performed before and after implantation. The dissolution of OCP crystals in a Col matrix was determined by immersing OCP/Col disks in a culture medium. OCP/Col had a constant pore size (~30 μm) regardless of OCP granule size. OCP in the Col matrix tended to convert to hydroxyapatite (HA) during the implantation. OCP/Col with the smallest granules of OCP enhances both bone regeneration and biodegradation the most through tartrate-resistant acid phosphatase (TRAP)-positive osteoclastic cellular resorption of OCP granules. The smallest OCP granules in the Col matrix showed the highest dissolution and had the greatest potential to form HA. The results indicated that the size of the included OCP granules can controll the osteoconductivity of OCP/Col. The overall results suggest that the physicochemical property of OCP crystals is a factor that determines the bone regenerative capacity of OCP/Col in critical-sized calvaria large bone defects in rats.

  2. Response of endothelial cells to decellularized extracellular matrix deposited by bone marrow mesenchymal stem cells

    PubMed Central

    Xu, Yue; Yan, Mengdie; Gong, Yihong; Chen, Lei; Zhao, Feng; Zhang, Zhaoqiang

    2014-01-01

    Objective: Evaluate the behavior and function of human umbilical vein endothelial cells (HUVECs) on decellularized extracellular matrix (ECM) deposited by bone marrow mesenchymal stem cells (BMSCs). Methods: Prepared through chemical approach, decellularized ECM was characterized by use of immunofluorescence staining. The morphology, attachment, proliferation and migration of HUVECs cultured on six-well tissue culture plastic (TCP) and decellularized ECM were investigated. Results: Decellularized ECM was successfully prepared without three-dimensional architecture disruption. This biological scaffold is similar to nature vascular ECM, preserved various matrix proteins such as type I collagen, type III collagen and fibronection. HUVECs on decellularized ECM showed well attachment and regular arrangement. Decellularized ECM could also significantly enhance the migration and proliferation potential of HUVECs in contrast to TCP. Conclusion: Deposited by BMSCs, ECM can affect the behavior of endothelial cell and could be used as a promising material in tissue engineering. PMID:25663998

  3. Time domain optical coherence tomography investigation of bone matrix interface in rat femurs

    NASA Astrophysics Data System (ADS)

    Rusu, Laura-Cristina; Negruá¹±iu, Meda-Lavinia; Sinescu, Cosmin; Hoinoiu, Bogdan; Topala, Florin-Ionel; Duma, Virgil-Florin; Rominu, Mihai; Podoleanu, Adrian G.

    2013-08-01

    The materials used to fabricate scaffolds for tissue engineering are derived from synthetic polymers, mainly from the polyester family, or from natural materials (e.g., collagen and chitosan). The mechanical properties and the structural properties of these materials can be tailored by adjusting the molecular weight, the crystalline state, and the ratio of monomers in the copolymers. Quality control and adjustment of the scaffold manufacturing process are essential to achieve high standard scaffolds. Most scaffolds are made from highly crystalline polymers, which inevitably result in their opaque appearance. Their 3-D opaque structure prevents the observation of internal uneven surface structures of the scaffolds under normal optical instruments, such as the traditional light microscope. The inability to easily monitor the inner structure of scaffolds as well as the interface with the old bone poses a major challenge for tissue engineering: it impedes the precise control and adjustment of the parameters that affect the cell growth in response to various mimicked culture conditions. The aim of this paper is to investigate the interface between the femur rat bone and the new bone that is obtained using a method of tissue engineering that is based on different artificial matrixes inserted in previously artificially induced defects. For this study, 15 rats were used in conformity with ethical procedures. In all the femurs a round defect was induced by drilling with a 1 mm spherical Co-Cr surgical drill. The matrixes used were Bioss and 4bone. These materials were inserted into the induced defects. The femurs were investigated at 1 week, 1 month, 2 month and three month after the surgical procedures. The interfaces were examined using Time Domain (TD) Optical Coherence Tomography (OCT) combined with Confocal Microscopy (CM). The optical configuration uses two single mode directional couplers with a superluminiscent diode as the source centered at 1300 nm. The scanning

  4. Multiscale, converging defects of macro-porosity, microstructure and matrix mineralization impact long bone fragility in NF1.

    PubMed

    Kühnisch, Jirko; Seto, Jong; Lange, Claudia; Schrof, Susanne; Stumpp, Sabine; Kobus, Karolina; Grohmann, Julia; Kossler, Nadine; Varga, Peter; Osswald, Monika; Emmerich, Denise; Tinschert, Sigrid; Thielemann, Falk; Duda, Georg; Seifert, Wenke; El Khassawna, Thaqif; Stevenson, David A; Elefteriou, Florent; Kornak, Uwe; Raum, Kay; Fratzl, Peter; Mundlos, Stefan; Kolanczyk, Mateusz

    2014-01-01

    Bone fragility due to osteopenia, osteoporosis or debilitating focal skeletal dysplasias is a frequent observation in the Mendelian disease Neurofibromatosis type 1 (NF1). To determine the mechanisms underlying bone fragility in NF1 we analyzed two conditional mouse models, Nf1Prx1 (limb knock-out) and Nf1Col1 (osteoblast specific knock-out), as well as cortical bone samples from individuals with NF1. We examined mouse bone tissue with micro-computed tomography, qualitative and quantitative histology, mechanical tensile analysis, small-angle X-ray scattering (SAXS), energy dispersive X-ray spectroscopy (EDX), and scanning acoustic microscopy (SAM). In cortical bone of Nf1Prx1 mice we detected ectopic blood vessels that were associated with diaphyseal mineralization defects. Defective mineral binding in the proximity of blood vessels was most likely due to impaired bone collagen formation, as these areas were completely devoid of acidic matrix proteins and contained thin collagen fibers. Additionally, we found significantly reduced mechanical strength of the bone material, which was partially caused by increased osteocyte volume. Consistent with these observations, bone samples from individuals with NF1 and tibial dysplasia showed increased osteocyte lacuna volume. Reduced mechanical properties were associated with diminished matrix stiffness, as determined by SAM. In line with these observations, bone tissue from individuals with NF1 and tibial dysplasia showed heterogeneous mineralization and reduced collagen fiber thickness and packaging. Collectively, the data indicate that bone fragility in NF1 tibial dysplasia is partly due to an increased osteocyte-related micro-porosity, hypomineralization, a generalized defect of organic matrix formation, exacerbated in the regions of tensional and bending force integration, and finally persistence of ectopic blood vessels associated with localized macro-porotic bone lesions.

  5. Multiscale, Converging Defects of Macro-Porosity, Microstructure and Matrix Mineralization Impact Long Bone Fragility in NF1

    PubMed Central

    Kühnisch, Jirko; Seto, Jong; Lange, Claudia; Schrof, Susanne; Stumpp, Sabine; Kobus, Karolina; Grohmann, Julia; Kossler, Nadine; Varga, Peter; Osswald, Monika; Emmerich, Denise; Tinschert, Sigrid; Thielemann, Falk; Duda, Georg; Seifert, Wenke; el Khassawna, Thaqif; Stevenson, David A.; Elefteriou, Florent; Kornak, Uwe; Raum, Kay; Fratzl, Peter; Mundlos, Stefan; Kolanczyk, Mateusz

    2014-01-01

    Bone fragility due to osteopenia, osteoporosis or debilitating focal skeletal dysplasias is a frequent observation in the Mendelian disease Neurofibromatosis type 1 (NF1). To determine the mechanisms underlying bone fragility in NF1 we analyzed two conditional mouse models, Nf1Prx1 (limb knock-out) and Nf1Col1 (osteoblast specific knock-out), as well as cortical bone samples from individuals with NF1. We examined mouse bone tissue with micro-computed tomography, qualitative and quantitative histology, mechanical tensile analysis, small-angle X-ray scattering (SAXS), energy dispersive X-ray spectroscopy (EDX), and scanning acoustic microscopy (SAM). In cortical bone of Nf1Prx1 mice we detected ectopic blood vessels that were associated with diaphyseal mineralization defects. Defective mineral binding in the proximity of blood vessels was most likely due to impaired bone collagen formation, as these areas were completely devoid of acidic matrix proteins and contained thin collagen fibers. Additionally, we found significantly reduced mechanical strength of the bone material, which was partially caused by increased osteocyte volume. Consistent with these observations, bone samples from individuals with NF1 and tibial dysplasia showed increased osteocyte lacuna volume. Reduced mechanical properties were associated with diminished matrix stiffness, as determined by SAM. In line with these observations, bone tissue from individuals with NF1 and tibial dysplasia showed heterogeneous mineralization and reduced collagen fiber thickness and packaging. Collectively, the data indicate that bone fragility in NF1 tibial dysplasia is partly due to an increased osteocyte-related micro-porosity, hypomineralization, a generalized defect of organic matrix formation, exacerbated in the regions of tensional and bending force integration, and finally persistence of ectopic blood vessels associated with localized macro-porotic bone lesions. PMID:24465906

  6. Identification of transcriptional macromolecular associations in human bone using browser based in silico analysis in a giant correlation matrix.

    PubMed

    Reppe, Sjur; Sachse, Daniel; Olstad, Ole K; Gautvik, Vigdis T; Sanderson, Paul; Datta, Harish K; Berg, Jens P; Gautvik, Kaare M

    2013-03-01

    Intracellular signaling is critically dependent on gene regulatory networks comprising physical molecular interactions. Presently, there is a lack of comprehensive databases for most human tissue types to verify such macromolecular interactions. We present a user friendly browser which helps to identify functional macromolecular interactions in human bone as significant correlations at the transcriptional level. The molecular skeletal phenotype has been characterized by transcriptome analysis of iliac crest bone biopsies from 84 postmenopausal women through quantifications of ~23,000 mRNA species. When the signal levels were inter-correlated, an array containing >260 million correlations was generated, thus recognizing the human bone interactome at the RNA level. The matrix correlation and p values were made easily accessible by a freely available online browser. We show that significant correlations within the giant matrix are reproduced in a replica set of 13 male vertebral biopsies. The identified correlations differ somewhat from transcriptional interactions identified in cell culture experiments and transgenic mice, thus demonstrating that care should be taken in extrapolating such results to the in vivo situation in human bone. The current giant matrix and web browser are a valuable tool for easy access to the human bone transcriptome and molecular interactions represented as significant correlations at the RNA-level. The browser and matrix should be a valuable hypothesis generating tool for identification of regulatory mechanisms and serve as a library of transcript relationships in human bone, a relatively inaccessible tissue.

  7. In vitro cartilage tissue engineering using cancellous bone matrix gelatin as a biodegradable scaffold.

    PubMed

    Yang, Bo; Yin, Zhanhai; Cao, Junling; Shi, Zhongli; Zhang, Zengtie; Song, Hongxing; Liu, Fuqiang; Caterson, Bruce

    2010-08-01

    In this study, we constructed tissue-engineered cartilage using allogeneic cancellous bone matrix gelatin (BMG) as a scaffold. Allogeneic BMG was prepared by sequential defatting, demineralization and denaturation. Isolated rabbit chondrocytes were seeded onto allogeneic cancellous BMG, and cell-BMG constructs were harvested after 1, 3 and 6 weeks for evaluation by hematoxylin and eosin staining for overall morphology, toluidine blue for extracellular matrix (ECM) proteoglycans, immunohistochemical staining for collagen type II and a transmission electron microscope for examining cellular microstructure on BMG. The prepared BMG was highly porous with mechanical strength adjustable by duration of demineralization and was easily trimmed for tissue repair. Cancellous BMG showed favorable porosity for cell habitation and metabolism material exchange with larger pore sizes (100-500 microm) than in cortical BMG (5-15 microm), allowing cell penetration. Cancellous BMG also showed good biocompatibility, which supported chondrocyte proliferation and sustained their differentiated phenotype in culture for up to 6 weeks. Rich and evenly distributed cartilage ECM proteoglycans and collagen type II were observed around chondrocytes on the surface and inside the pores throughout the cancellous BMG. Considering the large supply of banked bone allografts and relatively convenient preparation, our study suggests that allogeneic cancellous BMG is a promising scaffold for cartilage tissue engineering.

  8. Matrix metalloproteinase-based photodynamic molecular beacons for targeted destruction of bone metastases in vivo.

    PubMed

    Liu, T W; Akens, M K; Chen, J; Wilson, B C; Zheng, G

    2016-03-01

    The metastatic spread of cancer from the primary site or organ is one of its most devastating aspects, being responsible for up to 90% of cancer-associated mortality. Bone is one of the common sites of metastatic spread, including the vertebrae. Regardless of the treatment strategy, the clinical goals for patients with vertebral metastases are to improve the quality of life by preventing neurologic decline, to achieve durable pain relief and enhance local tumor control. However, in part due to the close proximity of the spinal cord, current treatment options are limited. We propose a novel therapeutic strategy with the use of photodynamic molecular beacons (PMBs) for targeted destruction of spinal metastases, particularly to de-bulk lesions as an adjuvant to vertebroplasty or kyphoplasty in order to mechanically stabilize weak or fractured vertebrae. The PDT efficacy of a matrix metalloproteinase-specific PMB is reported in a metstatic model that recapitulates the clinical features of tumor growth within the bone. We demonstrate that not only does tumor cell destruction occur but also the killing of bone stromal cells. The potential of PMB-PDT to destroy metastatic tumors, disrupt the osteolytic cycle and better preserve critical organs with an increased therapeutic window compared with conventional photosensitizers is demonstrated. PMID:26880165

  9. Histone deacetylase 3 supports endochondral bone formation by controlling cytokine signaling and matrix remodeling.

    PubMed

    Carpio, Lomeli R; Bradley, Elizabeth W; McGee-Lawrence, Meghan E; Weivoda, Megan M; Poston, Daniel D; Dudakovic, Amel; Xu, Ming; Tchkonia, Tamar; Kirkland, James L; van Wijnen, Andre J; Oursler, Merry Jo; Westendorf, Jennifer J

    2016-01-01

    Histone deacetylase (HDAC) inhibitors are efficacious epigenetic-based therapies for some cancers and neurological disorders; however, each of these drugs inhibits multiple HDACs and has detrimental effects on the skeleton. To better understand how HDAC inhibitors affect endochondral bone formation, we conditionally deleted one of their targets, Hdac3, pre- and postnatally in type II collagen α1 (Col2α1)-expressing chondrocytes. Embryonic deletion was lethal, but postnatal deletion of Hdac3 delayed secondary ossification center formation, altered maturation of growth plate chondrocytes, and increased osteoclast activity in the primary spongiosa. HDAC3-deficient chondrocytes exhibited increased expression of cytokine and matrix-degrading genes (Il-6, Mmp3, Mmp13, and Saa3) and a reduced abundance of genes related to extracellular matrix production, bone development, and ossification (Acan, Col2a1, Ihh, and Col10a1). Histone acetylation increased at and near genes that had increased expression. The acetylation and activation of nuclear factor κB (NF-κB) were also increased in HDAC3-deficient chondrocytes. Increased cytokine signaling promoted autocrine activation of Janus kinase (JAK)-signal transducer and activator of transcription (STAT) and NF-κB pathways to suppress chondrocyte maturation, as well as paracrine activation of osteoclasts and bone resorption. Blockade of interleukin-6 (IL-6)-JAK-STAT signaling, NF-κB signaling, and bromodomain extraterminal proteins, which recognize acetylated lysines and promote transcriptional elongation, significantly reduced Il-6 and Mmp13 expression in HDAC3-deficient chondrocytes and secondary activation in osteoclasts. The JAK inhibitor ruxolitinib also reduced osteoclast activity in Hdac3 conditional knockout mice. Thus, HDAC3 controls the temporal and spatial expression of tissue-remodeling genes and inflammatory responses in chondrocytes to ensure proper endochondral ossification during development. PMID:27507649

  10. Bone Regeneration Using Hydroxyapatite Sponge Scaffolds with In Vivo Deposited Extracellular Matrix.

    PubMed

    Ventura, Reiza Dolendo; Padalhin, Andrew Reyes; Min, Young-Ki; Lee, Byong-Taek

    2015-11-01

    There is currently an increased interest in studying the extracellular matrix (ECM) and its potential applications for tissue engineering and regenerative medicine. The ECM plays an important role by providing adhesive substrates to cells during migration, morphogenesis, differentiation, and homeostasis by signaling biochemical and biomechanical cues to cells. In this study, the ECM was incorporated into hydroxyapatite by implanting sponge replica scaffolds in subcutaneous pockets in rats, and the implants were tested for bone regeneration potential. The resulting scaffolds were characterized using scanning electron microscopy, confocal microscopy, DNA and RNA quantification, tissue staining, energy dispersive X-ray spectroscopy analysis, compressive strength testing, porosity, and pore size distribution analysis using bare scaffolds as a control reference. Biocompatibility was assessed using MC3T3-E1 preosteoblast cells and in vivo studies were carried out by implanting decellularized scaffolds in 11 mm radial defects in New Zealand rabbits for 4 and 8 weeks to determine the effect of the in vivo deposited ECM. Material characterization indicated that a 2-week decellularized scaffold was the best among the samples, with an evenly distributed ECM visible on hematoxylin and eosin-stained tissue sections, a compressive strength of 2.53 ± 0.68 MPa, a porosity of 58.08 ± 3.32% and a pore size distribution range of 10-150 μm. In vivo results showed no severe inflammation, with increased cell infiltration followed by dense matrix deposition after 4 weeks and new bone formation at 8 weeks. The results indicate that incorporation of an in vivo deposited ECM into ceramic scaffolds can potentially improve bone regeneration.

  11. Radiographic and histological evaluation of ectopic application of deproteinized bovine bone matrix

    PubMed Central

    da Silva, Rodrigo Carlos; Crivellaro, Viviane Rozeira; Giovanini, Allan Fernando; Scariot, Rafaela; Gonzaga, Carla Castiglia; Zielak, João César

    2016-01-01

    Objective: To evaluate, through radiographic and histological analysis, the tissue reaction induced by a biomaterial based on deproteinized bovine bone matrix (DBBM) in the muscle of sheep. Materials and Methods: Sixteen sheep were used. The animals underwent surgery to insert polyethylene tubes containing the biomaterial in the muscle of the lower back (ectopic site) and were euthanized after 3 and 6 months. Each sheep received three tubes: Group 1 - sham group (negative control - tube without biomaterial), Group 2 - particulate autogenous bone (positive control), and Group 3 - DBBM biomaterial (GenOx Inorg). The material removed was evaluated by radiographic, macroscopic, and microscopic analysis, descriptively. Results: Macroscopic analysis showed that Group 3 had a greater tissue volume maintenance. Microscopic analysis indicated that Group 1 had a higher concentration of dense, thin collagen fibers (3 and 6 months); in Group 2, there was a decrease in the inflammatory process and the deposition of dense, thin collagen fibers (3 and 6 months); in Group 3, the presence of a dense connective tissue was noted, in which the DBBM particles (3 months) were found. On the periphery of these particles, a deposition of basophilic material was found, indicating the formation of mineral particles and the formation of tissues with osteoid characteristics (6 months). Conclusion: Based on the results obtained, it can be concluded that the biomaterial based on DBBM led to the formation of tissue with similar characteristics to an osteoid matrix in a postoperative period of 6 months. However, none of the groups evaluated showed ectopic bone neoformation. PMID:27563599

  12. An Autologous Bone Marrow Mesenchymal Stem Cell–Derived Extracellular Matrix Scaffold Applied with Bone Marrow Stimulation for Cartilage Repair

    PubMed Central

    Tang, Cheng; Jin, Chengzhe; Du, Xiaotao; Yan, Chao; Min, Byoung-Hyun; Xu, Yan

    2014-01-01

    Purpose: It is well known that implanting a bioactive scaffold into a cartilage defect site can enhance cartilage repair after bone marrow stimulation (BMS). However, most of the current scaffolds are derived from xenogenous tissue and/or artificial polymers. The implantation of these scaffolds adds risks of pathogen transmission, undesirable inflammation, and other immunological reactions, as well as ethical issues in clinical practice. The current study was undertaken to evaluate the effectiveness of implanting autologous bone marrow mesenchymal stem cell–derived extracellular matrix (aBMSC-dECM) scaffolds after BMS for cartilage repair. Methods: Full osteochondral defects were performed on the trochlear groove of both knees in 24 rabbits. One group underwent BMS only in the right knee (the BMS group), and the other group was treated by implantation of the aBMSC-dECM scaffold after BMS in the left knee (the aBMSC-dECM scaffold group). Results: Better repair of cartilage defects was observed in the aBMSC-dECM scaffold group than in the BMS group according to gross observation, histological assessments, immunohistochemistry, and chemical assay. The glycosaminoglycan and DNA content, the distribution of proteoglycan, and the distribution and arrangement of type II and I collagen fibers in the repaired tissue in the aBMSC-dECM scaffold group at 12 weeks after surgery were similar to that surrounding normal hyaline cartilage. Conclusions: Implanting aBMSC-dECM scaffolds can enhance the therapeutic effect of BMS on articular cartilage repair, and this combination treatment is a potential method for successful articular cartilage repair. PMID:24666429

  13. Novel biocompatible polymeric blends for bone regeneration: Material and matrix design and development

    NASA Astrophysics Data System (ADS)

    Deng, Meng

    The first part of the work presented in this dissertation is focused on the design and development of novel miscible and biocompatible polyphosphazene-polyester blends as candidate materials for scaffold-based bone tissue engineering applications. Biodegradable polyesters such as poly(lactide-co-glycolide) (PLAGA) are among the most widely used polymeric materials for bone tissue engineering. However, acidic degradation products resulting from the bulk degradation mechanism often lead to catastrophic failure of the structure integrity, and adversely affect biocompatibility both in vitro and in vivo. One promising approach to circumvent these limitations is to blend PLAGA with other macromolecules that can buffer the acidic degradation products with a controlled degradation rate. Biodegradable polyphosphazenes (PPHOS), a new class of biomedical materials, have proved to be superior candidate materials to achieve this objective due to their unique buffering degradation products. A highly practical blending approach was adopted to develop novel biocompatible, miscible blends of these two polymers. In order to achieve this miscibility, a series of amino acid ester, alkoxy, aryloxy, and dipeptide substituted PPHOS were synthesized to promote hydrogen bonding interactions with PLAGA. Five mixed-substituent PPHOS compositions were designed and blended with PLAGA at different weight ratios producing candidate blends via a mutual solvent method. Preliminary characterization identified two specific side groups namely glycylglycine dipeptide and phenylphenoxy that resulted in improved blend miscibility and enhanced in vitro osteocompatibility. These findings led to the synthesis of a mixed-substituent polyphosphazene poly[(glycine ethyl glycinato)1(phenylphenoxy)1phosphazene] (PNGEGPhPh) for blending with PLAGA. Two dipeptide-based blends having weight ratios of PNGEGPhPh to PLAGA namely 25:75 (Matrix1) and 50:50 (Matrix2) were fabricated. Both of the blends were

  14. Periosteal Sharpey’s fibers: a novel bone matrix regulatory system?

    PubMed Central

    Aaron, Jean E.

    2012-01-01

    Sharpey’s “perforating” fibers (SF) are well known skeletally in tooth anchorage. Elsewhere they provide anchorage for the periosteum and are less well documented. Immunohistochemistry has transformed their potential significance by identifying their collagen type III (CIII) content and enabling their mapping in domains as permeating arrays of fibers (5–25 μ thick), protected from osteoclastic resorption by their poor mineralization. As periosteal extensions they are crucial in early skeletal development and central to intramembranous bone healing, providing unique microanatomical avenues for musculoskeletal exchange, their composition (e.g., collagen type VI, elastin, tenascin) combined with a multiaxial pattern of insertion suggesting a role more complex than attachment alone would justify. A proportion permeate the cortex to the endosteum (and beyond), fusing into a CIII-rich osteoid layer (<2 μ thick) encompassing all resting surfaces, and with which they apparently integrate into a PERIOSTEAL-SHARPEY FIBER-ENDOSTEUM (PSE) structural continuum. This intraosseous system behaves in favor of bone loss or gain depending upon extraneous stimuli (i.e., like Frost’s hypothetical “mechanostat”). Thus, the birefringent fibers are sensitive to humoral factors (e.g., estrogen causes retraction, rat femur model), physical activity (e.g., running causes expansion, rat model), aging (e.g., causes fragmentation, pig mandible model), and pathology (e.g., atrophied in osteoporosis, hypertrophied in osteoarthritis, human proximal femur), and with encroaching mineral particles hardening the usually soft parts. In this way the unobtrusive periosteal SF network may regulate bone status, perhaps even contributing to predictable “hotspots” of trabecular disconnection, particularly at sites of tension prone to fatigue, and with the network deteriorating significantly before bone matrix loss. PMID:22908007

  15. Adamts1 is highly induced in rachitic bones of FGF23 transgenic mice and participates in degradation of non-mineralized bone matrix collagen.

    PubMed

    Hu, Lijuan; Andersson, Göran; Jonsson, Kenneth B; Melhus, Håkan; Lind, Thomas

    2013-01-18

    Transgenic mice overexpressing fibroblast growth factor 23 (FGF23) in osteoblasts have a rachitic bone phenotype. These mice display hypomineralized bones, increased expression of osteoblast markers, but osteoclast numbers are unaltered or slightly reduced. Paradoxically, they show increased serum levels of the bone resorption marker CTX, a type I collagen degradation fragment. Here we analyzed a matrix metalloproteinase- (MMP-) like secreted protease, Adamts1, that has previously been associated with osteoblastic type I collagen breakdown in vitro. Bones from FGF23 transgenic (tg) mice displayed increased Adamts1 protein upon both immunohistological staining and Western blotting. We further found Adamts1 protein together with excessively degraded type I collagen in the non-mineralized bone fraction of FGF23 tg mice. A similar degradation pattern of type I collagen was noticed upon forced expression of Adamts1 in osteoblastic cells in vitro. Importantly, these Adamts1-expressing osteoblastic cells exhibited increased release of CTX fragments when cultured on demineralized bone discs. Together, these results demonstrate for the first time that Adamts1 can be highly induced in bone tissue and that this MMP-like protease can increase osteoblastic release of CTX fragments from non-mineralized bone. Thus, Adamts1 potentially contributes to the increased serum levels of CTX in rickets/osteomalacia.

  16. Immediate placement of a porous-tantalum, trabecular metal-enhanced titanium dental implant with demineralized bone matrix into a socket with deficient buccal bone: A clinical report

    PubMed Central

    Bencharit, Sompop; Byrd, Warren C.; Hosseini, Bashir

    2014-01-01

    A missing or deficient buccal alveolar bone plate is often an important limiting factor for immediate implant placement. Titanium dental implants enhanced with porous, tantalum-based trabecular metal material (PTTM) are designed for osseoincorporation, a combination of vascularized bone ingrowth and osseointegration (bone on-growth). Demineralized bone matrix (DBM) contains growth factors with good handling characteristics. However, the combination of these 2 materials in facial alveolar bone regeneration associated with immediate implant therapy has not been reported. A 65-year-old Asian woman presented with a failing central incisor. Most of the buccal alveolar bone plate of the socket was missing. A PTTM enhanced implant was immediately placed with DBM. Cone beam CT scans 12 months after the insertion of the definitive restoration showed regeneration of buccal alveolar bone. A combination of a PTTM enhanced implant, DBM, and a custom healing abutment may have an advantage in retaining biologically active molecules and form a scaffold for neovascularization and osteogenesis. This treatment protocol may be a viable option for immediate implant therapy in a failed tooth with deficient buccal alveolar bone. PMID:25702965

  17. Augmentation of intramembranous bone in rabbit calvaria using an occlusive barrier in combination with demineralized bone matrix (DBM): a pilot study.

    PubMed

    Beltrán, Víctor; Engelke, Wilfried; Prieto, Ruth; Valdivia-Gandur, Iván; Navarro, Pablo; Manzanares, María Cristina; Borie, Eduardo; Fuentes, Ramón

    2014-01-01

    The aim of this study was to histologically evaluate the performance of demineralized bone matrix (DBM) when compared with a blood clot in addition to an occlusive barrier in the bone regeneration process for bone defects in a rabbit model. Prefabricated metallic capsules with 4.5 mm and 3.5 mm dimensions were placed in five adult rabbit skulls. At the right side, the capsule was filled with DBM, and the clot was located on the left side. The barriers were supplied with a 0.5 mm horizontal peripheral flap and a vertical edge, fitting tightly into a circular slit prepared by a trephine in the skull. After a healing period of three months, the animals were sacrificed, and the samples were prepared for histological and histomorphometric analyses after capsule removal. Trabecular and medullar bone percentages were calculated from the different areas of the newly formed bone inside the metallic barriers, and non-parametric statistical analysis was used to describe the findings. The results showed a complete filling of newly formed bone inside the capsules of both groups. Less mature bone tissue was observed in the upper third of all samples, and a higher trabecular area was observed in the samples with DBM. The use of barriers resulted in the augmentation of newly formed bone in a three-month period. However, a higher trabecular area was observed in the barriers filled with DBM.

  18. Immediate placement of a porous-tantalum, trabecular metal-enhanced titanium dental implant with demineralized bone matrix into a socket with deficient buccal bone: a clinical report.

    PubMed

    Bencharit, Sompop; Byrd, Warren C; Hosseini, Bashir

    2015-04-01

    A missing or deficient buccal alveolar bone plate is often an important limiting factor for immediate implant placement. Titanium dental implants enhanced with porous tantalum-based trabecular metal material (PTTM) are designed for osseoincorporation, a combination of vascularized bone ingrowth and osseointegration (bone on-growth). Demineralized bone matrix (DBM) contains growth factors with good handling characteristics. However, the combination of these 2 materials in facial alveolar bone regeneration associated with immediate implant therapy has not been reported. A 65-year-old Asian woman presented with a failing central incisor. Most of the buccal alveolar bone plate of the socket was missing. A PTTM enhanced implant was immediately placed with DBM. Cone beam computed tomography scans 12 months after the insertion of the definitive restoration showed regeneration of buccal alveolar bone. A combination of a PTTM enhanced implant, DBM, and a custom healing abutment may have an advantage in retaining biologically active molecules and form a scaffold for neovascularization and osteogenesis. This treatment protocol may be a viable option for immediate implant therapy in a failed tooth with deficient buccal alveolar bone.

  19. Adamts1 is highly induced in rachitic bones of FGF23 transgenic mice and participates in degradation of non-mineralized bone matrix collagen.

    PubMed

    Hu, Lijuan; Andersson, Göran; Jonsson, Kenneth B; Melhus, Håkan; Lind, Thomas

    2013-01-18

    Transgenic mice overexpressing fibroblast growth factor 23 (FGF23) in osteoblasts have a rachitic bone phenotype. These mice display hypomineralized bones, increased expression of osteoblast markers, but osteoclast numbers are unaltered or slightly reduced. Paradoxically, they show increased serum levels of the bone resorption marker CTX, a type I collagen degradation fragment. Here we analyzed a matrix metalloproteinase- (MMP-) like secreted protease, Adamts1, that has previously been associated with osteoblastic type I collagen breakdown in vitro. Bones from FGF23 transgenic (tg) mice displayed increased Adamts1 protein upon both immunohistological staining and Western blotting. We further found Adamts1 protein together with excessively degraded type I collagen in the non-mineralized bone fraction of FGF23 tg mice. A similar degradation pattern of type I collagen was noticed upon forced expression of Adamts1 in osteoblastic cells in vitro. Importantly, these Adamts1-expressing osteoblastic cells exhibited increased release of CTX fragments when cultured on demineralized bone discs. Together, these results demonstrate for the first time that Adamts1 can be highly induced in bone tissue and that this MMP-like protease can increase osteoblastic release of CTX fragments from non-mineralized bone. Thus, Adamts1 potentially contributes to the increased serum levels of CTX in rickets/osteomalacia. PMID:23261447

  20. Mineralization process during acellular cementogenesis in rat molars: a histochemical and immunohistochemical study using fresh-frozen sections.

    PubMed

    Yamamoto, Tsuneyuki; Domon, Takanori; Takahashi, Shigeru; Anjuman, Khan Ara Yasmin; Fukushima, Chifumi; Wakita, Minoru

    2007-03-01

    This study was designed to detect tissue non-specific alkaline phosphatase (TNSALP) by Azo-dye staining, calcium by glyoxal bis (2-hydroxyanil) (GBHA) staining, bone sialoprotein (BSP) and osteopontin (OPN) by immunoperoxidase staining in developing rat molars, and also to discuss the mineralization process during acellular cementogenesis. To restrain a reduction in histochemical and immunohistochemical reactions, fresh-frozen undemineralized sections were prepared. Where the epithelial sheath was intact, TNSALP reaction was observed in the dental follicle, but not in the epithelial sheath. With the onset of dentin mineralization, the BSP- and OPN-immunoreactive, initial cementum layer appeared. At this point, cementoblasts had shown intense TNSALP reaction and GBHA reactive particles (=calcium-GBHA complex) appeared on the root surface. With further development, the reaction of TNSALP and GBHA became weak on the root surface. Previous studies have shown that the initial cementum is fibril-poor and that matrix vesicles and calciferous spherules appear on the root surface only during the initial cementogenesis. The findings mentioned above suggest that: during the initial cementogenesis, cementoblasts release matrix vesicles which result in calciferous spherules, corresponding to the GBHA reactive particles. The calciferous spherules trigger the mineralization of the initial cementum. After principal fiber attachment, mineralization advances along collagen fibrils without matrix vesicles. PMID:17043865

  1. Matrix Metalloproteinase 9 and Vascular Endothelial Growth Factor Are Essential for Osteoclast Recruitment into Developing Long Bones

    PubMed Central

    Engsig, Michael T.; Chen, Qing-Jun; Vu, Thiennu H.; Pedersen, Anne-Cecilie; Therkidsen, Bente; Lund, Leif R.; Henriksen, Kim; Lenhard, Thomas; Foged, Niels T.; Werb, Zena; Delaissé, Jean-Marie

    2000-01-01

    Bone development requires the recruitment of osteoclast precursors from surrounding mesenchyme, thereby allowing the key events of bone growth such as marrow cavity formation, capillary invasion, and matrix remodeling. We demonstrate that mice deficient in gelatinase B/matrix metalloproteinase (MMP)-9 exhibit a delay in osteoclast recruitment. Histological analysis and specialized invasion and bone resorption models show that MMP-9 is specifically required for the invasion of osteoclasts and endothelial cells into the discontinuously mineralized hypertrophic cartilage that fills the core of the diaphysis. However, MMPs other than MMP-9 are required for the passage of the cells through unmineralized type I collagen of the nascent bone collar, and play a role in resorption of mineralized matrix. MMP-9 stimulates the solubilization of unmineralized cartilage by MMP-13, a collagenase highly expressed in hypertrophic cartilage before osteoclast invasion. Hypertrophic cartilage also expresses vascular endothelial growth factor (VEGF), which binds to extracellular matrix and is made bioavailable by MMP-9 (Bergers, G., R. Brekken, G. McMahon, T.H. Vu, T. Itoh, K. Tamaki, K. Tanzawa, P. Thorpe, S. Itohara, Z. Werb, and D. Hanahan. 2000. Nat. Cell Biol. 2:737–744). We show that VEGF is a chemoattractant for osteoclasts. Moreover, invasion of osteoclasts into the hypertrophic cartilage requires VEGF because it is inhibited by blocking VEGF function. These observations identify specific actions of MMP-9 and VEGF that are critical for early bone development. PMID:11076971

  2. Preliminary in vivo studies on the osteogenic potential of bone morphogenetic proteins delivered from an absorbable puttylike polymer matrix.

    PubMed

    Andriano, K P; Chandrashekar, B; McEnery, K; Dunn, R L; Moyer, K; Balliu, C M; Holland, K M; Garrett, S; Huffer, W E

    2000-01-01

    This article describes preliminary in vivo studies evaluating the osteogeneic potential of bone morphogenetic proteins (BMPs) delivered from an absorbable puttylike polymer matrix. In the first study, bovine-derived bone morphogenetic proteins were incorporated in an polymer matrix consisting of 50:50 poly(DL-lactide-co-glycolide) dissolved in N-methyl-2-pyrrolidone. The matrix was implanted in an 8 mm critical-size calvarial defect created in the skull of adult Sprague-Dawley rats (n = 5 per treatment group). After 28 days, the implant sites were removed and examined for new bone formation, polymer degradation, and tissue reaction. Gamma-irradiated polymer matrices appeared to give more bone formation than nonirradiated samples (histological analysis; 2. 76 + 1.34 mm(2) of bone versus 1.30 + 0.90 mm(2) of bone, respectively and x-ray analysis; 27.2 + 15.9 mm(2) of bone versus 20. 7 + 16.7 mm(2) of bone, respectively) and less residual polymer (0.0 + 0.0 versus 0.2 + 0.4, respectively). The polymer implants with bone morphogenetic protein also gave less inflammatory response than the polymer controls (gamma irradiated polymer/BMP = 1.8 + 0.4 and nonirradiated polymer/BMP = 1.2 + 0.4 versus polymer only = 3.0 + 1. 2, respectively). However, despite trends in both the x-ray and histological data there was no statistical difference in the amount of new bone formed among the four treatment groups (P > 0.05). This was most likely due to the large variance in the data scatter and the small number of animals per group. In the second animal study, bovine-derived BMPs and the polymeric carrier were gamma irradiated separately, at doses of 1.5 or 2.5 Mrad, and their ability to form bone in a rat skull onlay model was evaluated using Sprague-Dawley rats (n = 5 per treatment group). Histomorphometry of skull caps harvested 28 days after implantation showed no significant differences as compared to non-irradiated samples, in implant area, new bone area, and percent new bone (P

  3. Heterotopic Ossification around the Knee after Internal Fixation of a Complex Tibial Plateau Fracture Combined with the Use of Demineralized Bone Matrix (DBM): A Case Report

    PubMed Central

    Nota, Sjoerd P.F.T.; Kloen, Peter

    2014-01-01

    Demineralized bone matrix has been successfully commercialized as an alternative bone graft material that not only can function as filler but also as an osteoinductive graft. Numerous studies have confirmed its beneficial use in clinical practice. Heterotopic ossification after internal fixation combined with the use of demineralized bone matrix has not been widely reported. In this paper we describe a 39 year old male who sustained a complex articular fracture that developed clinically significant heterotopic ossification after internal fixation with added demineralized bone matrix. Although we cannot be sure that there is a cause-and-effect relation between demineralized bone matrix and the excessive heterotopic ossification seen in our patient, it seems that some caution in using demineralised bone matrix in similar cases is warranted. Also, given the known inter- and intraproduct variability, the risks and benefits of these products should be carefully weighed. PMID:25692153

  4. Acceleration of tendon-bone healing in anterior cruciate ligament reconstruction using an enamel matrix derivative in a rat model.

    PubMed

    Kadonishi, Y; Deie, M; Takata, T; Ochi, M

    2012-02-01

    We examined whether enamel matrix derivative (EMD) could improve healing of the tendon-bone interface following reconstruction of the anterior cruciate ligament (ACL) using a hamstring tendon in a rat model. ACL reconstruction was performed in both knees of 30 Sprague-Dawley rats using the flexor digitorum tendon. The effect of commercially available EMD (EMDOGAIN), a preparation of matrix proteins from developing porcine teeth, was evaluated. In the left knee joint the space around the tendon-bone interface was filled with 40 µl of EMD mixed with propylene glycol alginate (PGA). In the right knee joint PGA alone was used. The ligament reconstructions were evaluated histologically and biomechanically at four, eight and 12 weeks (n = 5 at each time point). At eight weeks, EMD had induced a significant increase in collagen fibres connecting to bone at the tendon-bone interface (p = 0.047), whereas the control group had few fibres and the tendon-bone interface was composed of cellular and vascular fibrous tissues. At both eight and 12 weeks, the mean load to failure in the treated specimens was higher than in the controls (p = 0.009). EMD improved histological tendon-bone healing at eight weeks and biomechanical healing at both eight and 12 weeks. EMD might therefore have a human application to enhance tendon-bone repair in ACL reconstruction.

  5. Nanofiber–microsphere (nano-micro) matrices for bone regenerative engineering: a convergence approach toward matrix design

    PubMed Central

    Nelson, Clarke; Khan, Yusuf; Laurencin, Cato T.

    2014-01-01

    Bone is an essential organ for health and quality of life. Due to current shortfalls in therapy for bone tissue engineering, scientists have sought the application of synthetic materials as bone graft substitutes. As a composite organic/inorganic material with significant extra cellular matrix (ECM), one way to improve bone graft substitutes may be to engineer a synthetic matrix that is influenced by the physical appearance of natural ECM networks. In this work, the authors evaluate composite, hybrid scaffolds for bone tissue engineering based on composite ceramic/polymer microsphere scaffolds with synthetic ECM-mimetic networks in their pore spaces. Using thermally induced phase separation, nanoscale fibers were deposited in the pore spaces of structurally sound microsphere-based scaffold with a density proportionate to the initial polymer concentration. Porosimetry and mechanical testing indicated no significant changes in overall pore characteristics or mechanical integrity as a result of the fiber deposition process. These scaffolds displayed adequate mechanical integrity on the scale of human trabecular bone and supported the adhesion and proliferation of cultured mouse calvarial osteoblasts. Drawing from natural cues, these scaffolds may represent a new avenue forward for advanced bone tissue engineering scaffolds. PMID:26816620

  6. Acellular ostrich corneal stroma used as scaffold for construction of tissue-engineered cornea

    PubMed Central

    Liu, Xian-Ning; Zhu, Xiu-Ping; Wu, Jie; Wu, Zheng-Jie; Yin, Yong; Xiao, Xiang-Hua; Su, Xin; Kong, Bin; Pan, Shi-Yin; Yang, Hua; Cheng, Yan; An, Na; Mi, Sheng-Li

    2016-01-01

    AIM To assess acellular ostrich corneal matrix used as a scaffold to reconstruct a damaged cornea. METHODS A hypertonic saline solution combined with a digestion method was used to decellularize the ostrich cornea. The microstructure of the acellular corneal matrix was observed by transmission electron microscopy (TEM) and hematoxylin and eosin (H&E) staining. The mechanical properties were detected by a rheometer and a tension machine. The acellular corneal matrix was also transplanted into a rabbit cornea and cytokeratin 3 was used to check the immune phenotype. RESULTS The microstructure and mechanical properties of the ostrich cornea were well preserved after the decellularization process. In vitro, the methyl thiazolyl tetrazolium results revealed that extracts of the acellular ostrich corneas (AOCs) had no inhibitory effects on the proliferation of the corneal epithelial or endothelial cells or on the keratocytes. The rabbit lamellar keratoplasty showed that the transplanted AOCs were transparent and completely incorporated into the host cornea while corneal turbidity and graft dissolution occurred in the acellular porcine cornea (APC) transplantation. The phenotype of the reconstructed cornea was similar to a normal rabbit cornea with a high expression of cytokeratin 3 in the superficial epithelial cell layer. CONCLUSION We first used AOCs as scaffolds to reconstruct damaged corneas. Compared with porcine corneas, the anatomical structures of ostrich corneas are closer to those of human corneas. In accordance with the principle that structure determines function, a xenograft lamellar keratoplasty also confirmed that the AOC transplantation generated a superior outcome compared to that of the APC graft. PMID:27158598

  7. A chondroitin sulfate chain attached to the bone dentin matrix protein 1 NH2-terminal fragment.

    PubMed

    Qin, Chunlin; Huang, Bingzhen; Wygant, James N; McIntyre, Bradley W; McDonald, Charles H; Cook, Richard G; Butler, William T

    2006-03-24

    Dentin matrix protein 1 (DMP1) is an acidic noncollagenous protein shown by gene ablations to be critical for the proper mineralization of bone and dentin. In the extracellular matrix of these tissues DMP1 is present as fragments representing the NH2-terminal (37 kDa) and COOH-terminal (57 kDa) portions of the cDNA-deduced amino acid sequence. During our separation of bone noncollagenous proteins, we observed a high molecular weight, DMP1-related component (designated DMP1-PG). We purified DMP1-PG with a monoclonal anti-DMP1 antibody affinity column. Amino acid analysis and Edman degradation of tryptic peptides proved that the core protein for DMP1-PG is the 37-kDa fragment of DMP1. Chondroitinase treatments demonstrated that the slower migration rate of DMP1-PG is due to the presence of glycosaminoglycan. Quantitative disaccharide analysis indicated that the glycosaminoglycan is made predominantly of chondroitin 4-sulfate. Further analysis on tryptic peptides led us to conclude that a single glycosaminoglycan chain is linked to the core protein via Ser74, located in the Ser74-Gly75 dipeptide, an amino acid sequence specific for the attachment of glycosaminoglycans. Our findings show that in addition to its existence as a phosphoprotein, the NH2-terminal fragment from DMP1 occurs as a proteoglycan. Amino acid sequence alignment analysis showed that the Ser74-Gly75 dipeptide and its flanking regions are highly conserved among a wide range of species from caiman to the Homo sapiens, indicating that this glycosaminoglycan attachment domain has survived an extremely long period of evolution pressure, suggesting that the glycosaminoglycan may be critical for the basic biological functions of DMP1.

  8. Parallel high-resolution confocal Raman SEM analysis of inorganic and organic bone matrix constituents

    PubMed Central

    van Apeldoorn, A.A; Aksenov, Y; Stigter, M; Hofland, I; de Bruijn, J.D; Koerten, H.K; Otto, C; Greve, J; van Blitterswijk, C.A

    2005-01-01

    In many multi-disciplinary fields of science, such as tissue engineering, where material and biological sciences are combined, there is a need for a tool that combines ultrastructural and chemical data analysis in a non-destructive manner at high resolution. We show that a combination of confocal Raman spectroscopy (CRS) and scanning electron microscopy (SEM) can be used for such analysis. Studies of atomic composition can be done by X-ray microanalysis in SEM, but this is only possible for atomic numbers greater than five and does not reveal molecular identity. Raman spectroscopy, however, can provide information on molecular composition and identity by detection of wavelength shifts caused by molecular vibrations. In this study, CRS–SEM revealed that early in vitro-formed bone extracellular matrix (ECM) produced by rat osteoprogenitor cells resembles mature bone chemically. We gained insight into the structure and chemical composition of the ECM, which was composed of mainly mineralized collagen type I fibres and areas of dense carbonated calcium phosphate related to the collagen fibre density, as revealed by Raman imaging of SEM samples. We found that CRS–SEM allows the study of specimens in a non-destructive manner and provides high-resolution structural and chemical information about inorganic and organic constituents by parallel measurements on the same sample. PMID:16849162

  9. Human fibroblast-derived extracellular matrix constructs for bone tissue engineering applications.

    PubMed

    Tour, Gregory; Wendel, Mikael; Tcacencu, Ion

    2013-10-01

    We exploited the biomimetic approach to generate constructs composed of synthetic biphasic calcium phosphate ceramic and extracellular matrix (SBC-ECM) derived from adult human dermal fibroblasts in complete xeno-free culture conditions. The construct morphology and composition were assessed by scanning electron microscopy, histology, immunohistochemistry, Western blot, glycosaminoglycan, and hydroxyproline assays. Residual DNA quantification, endotoxin testing, and local inflammatory response after implantation in a rat critical-sized calvarial defect were used to access the construct biocompatibility. Moreover, in vitro interaction of human mesenchymal stem cells (hMSCs) with the constructs was studied. The bone marrow- and adipose tissue-derived mesenchymal stem cells were characterized by flow cytometry and tested for osteogenic differentiation capacity prior seeding onto SBC-ECM, followed by alkaline phosphatase, 3-(4,5-dimethythiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay, and real-time quantitative polymerase chain reaction to assess the osteogenic differentiation of hMSCs after seeding onto the constructs at different time intervals. The SBC-ECM constructs enhanced osteogenic differentiation of hMSCs in vitro and exhibited excellent handling properties and high biocompatibility in vivo. Our results highlight the ability to generate in vitro fibroblast-derived ECM constructs in complete xeno-free conditions as a step toward clinical translation, and the potential use of SBC-ECM in craniofacial bone tissue engineering applications.

  10. Quantum dots as mineral- and matrix-specific strain gages for bone biomechanical studies

    NASA Astrophysics Data System (ADS)

    Zhu, Peizhi; Xu, Jiadi; Morris, Michael; Ramamoorthy, Ayyalusamy; Sahar, Nadder; Kohn, David

    2009-02-01

    We report the use of quantum dots (Qdots) as strain gages in the study of bone biomechanics using solid state nuclear magnetic resonance (NMR) spectroscopy. We have developed solid state NMR sample cells for investigation of deformations of bone tissue components at loads up to several Mega Pascal. The size constraints of the NMR instrumentation limit the bone specimen diameter and length to be no greater than 2-3 mm and 30 mm respectively. Further, magic angle spinning (MAS) solid state NMR experiments require the use of non-metallic apparatus that can be rotated at kilohertz rates. These experimental constraints preclude the use of standard biomechanical measurement systems. In this paper we explore the use of quantum dot center of gravity measurement as a strain gage technology consistent with the constraints of solid state NMR. We use Qdots that bind calcium (625 nm emission) and collagen (705 nm emission) for measurement of strain in these components. Compressive loads are applied to a specimen in a cell through a fine pitch screw turned with a mini-torque wrench. Displacement is measured as changes in the positions of arrays of quantum dots on the surface of a specimen. Arrays are created by spotting the specimen with dilute suspensions of Qdots. Mineral labeling is achieved with 705 nm carboxylated dots and matrix labeling with 565 nm quantum dots conjugated to collagen I antibodies. After each load increment the new positions of the quantum dots are measured by fluorescence microscopy. Changes in Qdot center of gravity as a function of applied load can be measured with submicron accuracy.

  11. Ornamenting 3D printed scaffolds with cell-laid extracellular matrix for bone tissue regeneration.

    PubMed

    Pati, Falguni; Song, Tae-Ha; Rijal, Girdhari; Jang, Jinah; Kim, Sung Won; Cho, Dong-Woo

    2015-01-01

    3D printing technique is the most sophisticated technique to produce scaffolds with tailorable physical properties. But, these scaffolds often suffer from limited biological functionality as they are typically made from synthetic materials. Cell-laid mineralized ECM was shown to be potential for improving the cellular responses and drive osteogenesis of stem cells. Here, we intend to improve the biological functionality of 3D-printed synthetic scaffolds by ornamenting them with cell-laid mineralized extracellular matrix (ECM) that mimics a bony microenvironment. We developed bone graft substitutes by using 3D printed scaffolds made from a composite of polycaprolactone (PCL), poly(lactic-co-glycolic acid) (PLGA), and β-tricalcium phosphate (β-TCP) and mineralized ECM laid by human nasal inferior turbinate tissue-derived mesenchymal stromal cells (hTMSCs). A rotary flask bioreactor was used to culture hTMSCs on the scaffolds to foster formation of mineralized ECM. A freeze/thaw cycle in hypotonic buffer was used to efficiently decellularize (97% DNA reduction) the ECM-ornamented scaffolds while preserving its main organic and inorganic components. The ECM-ornamented 3D printed scaffolds supported osteoblastic differentiation of newly-seeded hTMSCs by upregulating four typical osteoblastic genes (4-fold higher RUNX2; 3-fold higher ALP; 4-fold higher osteocalcin; and 4-fold higher osteopontin) and increasing calcium deposition compared to bare 3D printed scaffolds. In vivo, in ectopic and orthotopic models in rats, ECM-ornamented scaffolds induced greater bone formation than that of bare scaffolds. These results suggest a valuable method to produce ECM-ornamented 3D printed scaffolds as off-the-shelf bone graft substitutes that combine tunable physical properties with physiological presentation of biological signals.

  12. Using bone marrow matrix to analyze meprobamate for forensic toxicological purposes.

    PubMed

    Bévalot, F; Gustin, M P; Cartiser, N; Gaillard, Y; Le Meur, C; Fanton, L; Guitton, J; Malicier, D

    2013-09-01

    Bone marrow (BM) analysis is of forensic interest for postmortem toxicological investigations where blood samples are unavailable or unusable. Due to the lack of studies, it remains difficult to interpret concentrations of xenobiotics measured in this matrix. Based on a statistical approach published previously to interpret meprobamate concentrations in bile and vitreous humor, we propose here a diagnostic test for interpretation of BM meprobamate concentrations from analysis of 99 sets of autopsy data. The mean age was 48 years (range 18-80 years, one unknown) for males and 50 years (range 19-80 years, one unknown) for females, with a male/female ratio at 0.768. A BM concentration threshold of 11.3 μg/g was found to be statistically equivalent to that of a blood meprobamate concentration threshold of 50 μg/ml in distinguishing overdose from therapeutic use. The intrinsic qualities of this diagnostic test were good with sensitivity of 0.82 and specificity of 0.92. Compared to previous tests published with the same objective on vitreous humor and bile, this study shows that BM is a useful alternative matrix to reveal meprobamate overdose when blood, vitreous humor, and bile are not available or unusable.

  13. Matrix Gla protein inhibition of tooth mineralization.

    PubMed

    Kaipatur, N R; Murshed, M; McKee, M D

    2008-09-01

    Extracellular matrix (ECM) mineralization is regulated by mineral ion availability, proteins, and other molecular determinants. To investigate protein regulation of mineralization in tooth dentin and cementum, and in alveolar bone, we expressed matrix Gla protein (MGP) ectopically in bones and teeth in mice, using an osteoblast/odontoblast-specific 2.3-kb Col1a1 promoter. Mandibles were analyzed by radiography, micro-computed tomography, light microscopy, histomorphometry, and transmission electron microscopy. While bone and tooth ECMs were established in the Col1a1-Mgp mice, extensive hypomineralization was observed, with values of unmineralized ECM from four- to eight-fold higher in dentin and alveolar bone when compared with that in wild-type tissues. Mineralization was virtually absent in tooth root dentin and cellular cementum, while crown dentin showed "breakthrough" areas of mineralization. Acellular cementum was lacking in Col1a1-Mgp teeth, and unmineralized osteodentin formed within the pulp. These results strengthen the view that bone and tooth mineralization is critically regulated by mineralization inhibitors. PMID:18719210

  14. Reconstruction of coup de sabre deformity (linear localized scleroderma) by using galeal frontalis muscle flap and demineralized bone matrix combination.

    PubMed

    Cavusoglu, Tarik; Yazici, Ilker; Vargel, Ibrahim; Karakaya, Esen Ibrahim

    2011-01-01

    In this clinical report, we are presenting the combination of demineralized bone matrix combined with bilateral galea frontalis flaps. Based on our 6-month results, this seems to be a reasonable combination to accomplish long-lasting restoration of forehead defects related to en coup de sabre linear localized scleroderma.

  15. The tent pole splint: a bone-supported stereolithographic surgical splint for the soft tissue matrix expansion graft procedure.

    PubMed

    Cillo, Joseph E; Theodotou, Nicholas; Samuels, Marc; Krajekian, Joseph

    2010-06-01

    This report details the use of computer-aided planning and intraoperative stereolithographic direct-bone-contact surgical splints for the accurate extraoral placement of dental implants in the soft tissue matrix expansion (tent pole) graft of the severely resorbed mandible. PMID:20231048

  16. Biological assessment of a calcium silicate incorporated hydroxyapatite-gelatin nanocomposite: a comparison to decellularized bone matrix.

    PubMed

    Lee, Dong Joon; Padilla, Ricardo; Zhang, He; Hu, Wei-Shou; Ko, Ching-Chang

    2014-01-01

    Our laboratory utilized biomimicry to develop a synthetic bone scaffold based on hydroxyapatite-gelatin-calcium silicate (HGCS). Here, we evaluated the potential of HGCS scaffold in bone formation in vivo using the rat calvarial critical-sized defect (CSD). Twelve Sprague-Dawley rats were randomized to four groups: control (defect only), decellularized bone matrix (DECBM), and HGCS with and without multipotent adult progenitor cells (MAPCs). DECBM was prepared by removing all the cells using SDS and NH4OH. After 12 weeks, the CSD specimens were harvested to evaluate radiographical, histological, and histomorphometrical outcomes. The in vitro osteogenic effects of the materials were studied by focal adhesion, MTS, and alizarin red. Micro-CT analysis indicated that the DECBM and the HGCS scaffold groups developed greater radiopaque areas than the other groups. Bone regeneration, assessed using histological analysis and fluorochrome labeling, was the highest in the HGCS scaffold seeded with MAPCs. The DECBM group showed limited osteoinductivity, causing a gap between the implant and host tissue. The group grafted with HGCS+MAPCs resulting in twice as much new bone formation seems to indicate a role for effective bone regeneration. In conclusion, the novel HGCS scaffold could improve bone regeneration and is a promising carrier for stem cell-mediated bone regeneration. PMID:25054149

  17. Development of a Three-Dimensional Bone-Like Construct in a Soft Self-Assembling Peptide Matrix

    PubMed Central

    Marí-Buyé, Núria; Luque, Tomás; Navajas, Daniel

    2013-01-01

    This work describes the development of a three-dimensional (3D) model of osteogenesis using mouse preosteoblastic MC3T3-E1 cells and a soft synthetic matrix made out of self-assembling peptide nanofibers. By adjusting the matrix stiffness to very low values (around 120 Pa), cells were found to migrate within the matrix, interact forming a cell–cell network, and create a contracted and stiffer structure. Interestingly, during this process, cells spontaneously upregulate the expression of bone-related proteins such as collagen type I, bone sialoprotein, and osteocalcin, indicating that the 3D environment enhances their osteogenic potential. However, unlike MC3T3-E1 cultures in 2D, the addition of dexamethasone is required to acquire a final mature phenotype characterized by features such as matrix mineralization. Moreover, a slight increase in the hydrogel stiffness (threefold) or the addition of a cell contractility inhibitor (Rho kinase inhibitor) abrogates cell elongation, migration, and 3D culture contraction. However, this mechanical inhibition does not seem to noticeably affect the osteogenic process, at least at early culture times. This 3D bone model intends to emphasize cell–cell interactions, which have a critical role during tissue formation, by using a compliant unrestricted synthetic matrix. PMID:23157379

  18. Bone matrix calcification during embryonic and postembryonic rat calvarial development assessed by SEM-EDX spectroscopy, XRD, and FTIR spectroscopy.

    PubMed

    Henmi, Akiko; Okata, Hiroshi; Anada, Takahisa; Yoshinari, Mariko; Mikami, Yasuto; Suzuki, Osamu; Sasano, Yasuyuki

    2016-01-01

    Bone mineral is constituted of biological hydroxyapatite crystals. In developing bone, the mineral crystal matures and the Ca/P ratio increases. However, how an increase in the Ca/P ratio is involved in maturation of the crystal is not known. The relationships among organic components and mineral changes are also unclear. The study was designed to investigate the process of calcification during rat calvarial bone development. Calcification was evaluated by analyzing the atomic distribution and concentration of Ca, P, and C with scanning electron microscopy (SEM)-energy-dispersive X-ray (EDX) spectroscopy and changes in the crystal structure with X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy. Histological analysis showed that rat calvarial bone formation started around embryonic day 16. The areas of Ca and P expanded, matching the region of the developing bone matrix, whereas the area of C became localized around bone. X-ray diffraction and FTIR analysis showed that the amorphous-like structure of the minerals at embryonic day 16 gradually transformed into poorly crystalline hydroxyapatite, whereas the proportion of mineral to protein increased until postnatal week 6. FTIR analysis also showed that crystallization of hydroxyapatite started around embryonic day 20, by which time SEM-EDX spectroscopy showed that the Ca/P ratio had increased and the C/Ca and C/P ratios had decreased significantly. The study suggests that the Ca/P molar ratio increases and the proportion of organic components such as proteins of the bone matrix decreases during the early stage of calcification, whereas crystal maturation continues throughout embryonic and postembryonic bone development.

  19. The effects of orbital spaceflight on bone histomorphometry and messenger ribonucleic acid levels for bone matrix proteins and skeletal signaling peptides in ovariectomized growing rats

    NASA Technical Reports Server (NTRS)

    Cavolina, J. M.; Evans, G. L.; Harris, S. A.; Zhang, M.; Westerlind, K. C.; Turner, R. T.

    1997-01-01

    A 14-day orbital spaceflight was performed using ovariectomized Fisher 344 rats to determine the combined effects of estrogen deficiency and near weightlessness on tibia radial bone growth and cancellous bone turnover. Twelve ovariectomized rats with established cancellous osteopenia were flown aboard the space shuttle Columbia (STS-62). Thirty ovariectomized rats were housed on earth as ground controls: 12 in animal enclosure modules, 12 in vivarium cages, and 6 killed the day of launch for baseline measurements. An additional 18 ovary-intact rats were housed in vivarium cages as ground controls: 8 rats were killed as baseline controls and the remaining 10 rats were killed 14 days later. Ovariectomy increased periosteal bone formation at the tibia-fibula synostosis; cancellous bone resorption and formation in the secondary spongiosa of the proximal tibial metaphysis; and messenger RNA (mRNA) levels for the prepro-alpha2(1) subunit of type 1 collagen, osteocalcin, transforming growth factor-beta, and insulin-like growth factor I in the contralateral proximal tibial metaphysis and for the collagen subunit in periosteum pooled from tibiae and femora and decreased cancellous bone area. Compared to ovariectomized weight-bearing rats, the flight group experienced decreases in periosteal bone formation, collagen subunit mRNA levels, and cancellous bone area. The flight rats had a small decrease in the cancellous mineral apposition rate, but no change in the calculated bone formation rate. Also, spaceflight had no effect on cancellous osteoblast and osteoclast perimeters or on mRNA levels for bone matrix proteins and signaling peptides. On the other hand, spaceflight resulted in an increase in bone resorption, as ascertained from the diminished retention of a preflight fluorochrome label. This latter finding suggests that osteoclast activity was increased. In a follow-up ground-based experiment, unilateral sciatic neurotomy of ovariectomized rats resulted in cancellous

  20. Ex vivo evaluation of acellular and cellular collagen-glycosaminoglycan flowable matrices.

    PubMed

    Hodgkinson, Tom; Bayat, Ardeshir

    2015-08-01

    Collagen-glycosaminoglycan flowable matrices (CGFM) are increasingly finding utility in a diversifying number of cutaneous surgical procedures. Cellular in-growth and vascularisation of CGFM remain rate-limiting steps, increasing cost and decreasing efficacy. Through in vitro and ex vivo culture methods, this study investigated the improvement of injectable CGFM by the incorporation of hyaluronan (HA) and viable human cells (primary human dermal fibroblasts (PHDFs) and bone marrow-derived mesenchymal stem cells (BM-MSCs)). Ex vivo investigations included the development and evaluation of a human cutaneous wound healing model for the comparison of dermal substitutes. Cells mixed into the Integra Flowable Wound Matrix (IFWM), a commercially available CGFM, were confirmed to be viable and proliferative through MTT assays (p  <  0.05). PHDFs proliferated with greater rapidity than BM-MSCs up to 1 week in culture (p  <  0.05), with PHDF proliferation further enhanced by HA supplementation (p  <  0.05). After scaffold mixing, gene expression was not significantly altered (qRT-PCR). PHDF and BM-MSC incorporation into ex vivo wound models significantly increased re-epithelialisation rate, with maximal effects observed for BM-MSC supplemented IFWM. HA supplementation to PHDF populated IFWM increased re-epithelialisation but had no significant effect on BM-MSC populated IFWM. In conclusion, when combined with PHDF, HA increased re-epithelialisation in IFWM. BM-MSC incorporation significantly improved re-epithelialisation in ex vivo models over acellular and PHDF populated scaffolds. Viable cell incorporation into IFWM has potential to significantly benefit wound healing in chronic and acute cutaneous injuries by allowing a point-of-care matrix to be formed from autologous or allogenic cells and bioactive molecules. PMID:26181360

  1. In vitro assessment of biodurability: acellular systems.

    PubMed Central

    de Meringo, A; Morscheidt, C; Thélohan, S; Tiesler, H

    1994-01-01

    The assessment of biodurability of man-made vitreous fibers is essential to the limitation of health hazards associated with human exposure to environments in which respirable fibers are present. In vitro acellular systems provide effective test methods of measuring fiber solubility provided care is taken to select the most suitable solvent and test conditions for the specific fiber type and dimension. PMID:7882955

  2. A Novel High Mechanical Property PLGA Composite Matrix Loaded with Nanodiamond-Phospholipid Compound for Bone Tissue Engineering.

    PubMed

    Zhang, Fan; Song, Qingxin; Huang, Xuan; Li, Fengning; Wang, Kun; Tang, Yixing; Hou, Canglong; Shen, Hongxing

    2016-01-20

    A potential bone tissue engineering material was produced from a biodegradable polymer, poly(lactic-co-glycolic acid) (PLGA), loaded with nanodiamond phospholipid compound (NDPC) via physical mixing. On the basis of hydrophobic effects and physical absorption, we modified the original hydrophilic surface of the nanodiamond (NDs) with phospholipids to be amphipathic, forming a typical core-shell structure. The ND-phospholipid weight ratio was optimized to generate sample NDPC50 (i.e., ND-phospholipid weight ratio of 100:50), and NDPC50 was able to be dispersed in a PLGA matrix at up to 20 wt %. Compared to a pure PLGA matrix, the introduction of 10 wt % of NDPC (i.e., sample NDPC50-PF10) resulted in a significant improvement in the material's mechanical and surface properties, including a decrease in the water contact angle from 80 to 55°, an approximately 100% increase in the Young's modulus, and an approximate 550% increase in hardness, thus closely resembling that of human cortical bone. As a novel matrix supporting human osteoblast (hFOB1.19) growth, NDPC50-PFs with different amounts of NDPC50 demonstrated no negative effects on cell proliferation and osteogenic differentiation. Furthermore, we focused on the behaviors of NDPC-PFs implanted into mice for 8 weeks and found that NDPC-PFs induced acceptable immune response and can reduce the rapid biodegradation of PLGA matrix. Our results represent the first in vivo research on ND (or NDPC) as nanofillers in a polymer matrix for bone tissue engineering. The high mechanical properties, good in vitro and in vivo biocompatibility, and increased mineralization capability suggest that biodegradable PLGA composite matrices loaded with NDPC may potentially be useful for a variety of biomedical applications, especially bone tissue engineering.

  3. Intentional replantation of periodontally hopeless teeth using a combination of enamel matrix derivative and demineralized freeze-dried bone allograft.

    PubMed

    Baltacioglu, Ersa; Tasdemir, Tamer; Yuva, Pinar; Celik, Davut; Sukuroglu, Erkan

    2011-02-01

    This study evaluated the clinical and radiographic results of the intentional replantation of periodontally hopeless teeth with combined enamel matrix derivative and demineralized freeze-dried bone allograft therapy. Eleven patients (five female, six male; age range, 13 to 53 years) with 12 periodontally hopeless teeth resulting from extensive alveolar bone loss and vertical defects extending to the apexes were studied. At the 12-month clinical and radiologic follow-up, significant improvement was observed for all clinical and radiographic parameters except gingival recession (P < .05). These preliminary findings show that intentional replantation combined with regenerative techniques is a successful alternative to tooth extraction.

  4. Fiber-matrix interface studies on bioabsorbable composite materials for internal fixation of bone fractures. I. Raw material evaluation and measurement of fiber-matrix interfacial adhesion.

    PubMed

    Slivka, M A; Chu, C C; Adisaputro, I A

    1997-09-15

    The objective of this study was to characterize and evaluate the performance of various fiber-matrix composite systems by studying the mechanical, thermal, and physical properties of the fiber and matrix components, and by studying the fiber-matrix interface adhesion strength using both microbond and fragmentation methods. The composites studies were poly(L-lactic acid) (PLLA) matrix reinforced with continuous fibers of either nonabsorbable AS4 carbon (C), absorbable calcium phosphate (CaP), poly(glycolic acid) (PGA), or chitin. Carbon and CaP single fibers had high Young's moduli and failed in a brittle manner. PGA and chitin single fibers had relatively lower Young's moduli and relatively higher ductility. Upon in vitro hydrolysis, CaP fibers retained 17% of their tensile strength and 39% of their Young's modulus after 12 h, PCA fibers retained 10% of their tensile strength and 52% of their Young's modulus after 16 days, and chitin fibers retained 87% of their tensile strength and 130% of their Young's modulus after 25 days. PLLA films had much lower strength and Young's moduli, but much higher ductility relative to the single fibers. Using the microbond method, the initial fiber-matrix interfacial shear strength (IFSS) of C/PLLA and CaP/PLLA microcomposites was 33.9 and 12.6 MPa, respectively. Upon in vitro hydrolysis, C/PLLA retained 49% of IFSS after 15 days and CaP/PLLA retained 46% of IFSS after 6 h. Using a fiber fragmentation method, the initial IFSS of C/PLLA, CaP/PLLA, and chitin/ PLLA was 22.2, 15.6, and 28.3 MPa, respectively. The performance of carbon fibers and C/PLLA composites was superior to the other fibers and fiber/PLLA systems, but the carbon fiber was nonabsorbable. CaP had the most suitable modulus of the absorbable fibers for fixing cortical bone fracture, but its rapid deterioration of mechanical properties and loss of IFSS limits its use. PGA and chitin fibers had suitable mechanical properties and their retention for fixing cancellous

  5. Remineralization of demineralized bone matrix in critical size cranial defects in rats: A 6-month follow-up study.

    PubMed

    Horváthy, Dénes B; Vácz, Gabriella; Toró, Ildikó; Szabó, Tamás; May, Zoltán; Duarte, Miguel; Hornyák, István; Szabó, Bence T; Dobó-Nagy, Csaba; Doros, Attila; Lacza, Zsombor

    2016-10-01

    The key drawback of using demineralized bone matrix (DBM) is its low initial mechanical stability due to the severe depletion of mineral content. In the present study, we investigated the long-term regeneration of DBM in a critical size bone defect model and investigated the remineralization after 6 months. Bone defects were created in the cranium of male Wistar rats which were filled with DBM or left empty as negative control. In vivo bone formation was monitored with computed tomography after 11, 19, and 26 weeks postoperatively. After 6 months, parietal bones were subjected to micro-CT. Mineral content was determined with spectrophotometric analysis. After 11 weeks the DBM-filled bone defects were completely closed, while empty defects were still open. Density of the DBM-treated group increased significantly while the controls remained unchanged. Quantitative analysis by micro-CT confirmed the in vivo results, bone volume/tissue volume was significantly lower in the controls than in the DBM group. The demineralization procedure depleted the key minerals of the bone to a very low level. Six months after implantation Ca, P, Na, Mg, Zn, and Cr contents were completely restored to the normal level, while K, Sr, and Mn were only partially restored. The remineralization process of DBM is largely complete by the 6th month after implantation in terms of bone density, structure, and key mineral levels. Although DBM does not provide sufficient sources for any of these minerals, it induces a faster and more complete regeneration process. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 104B: 1336-1342, 2016.

  6. Preparation and characterization of an acellular bovine pericardium intended for manufacture of valve bioprostheses.

    PubMed

    Goissis, Gilberto; Giglioti, Aparecida de Fátima; Braile, Domingo Marcolino

    2011-05-01

    Major problems with biological heart valves post-implantation are associated with progressive structural deterioration and calcification attributed to glutaraldehyde processing, dead cells, and cell fragments present in the native tissue. In spite of these problems, glutaraldehyde still is the reagent of choice. The results with acellular matrix xenograft usually prepared by detergent treatment in association with enzymes are rather conflicting because while preserving mechanical properties, tissue morphology and collagen structure are process dependent. This work describes a chemical approach for the preparation of an acellular bovine pericardium matrix intended for the manufacture of heart valve bioprostheses. Cell removal was performed by an alkaline extraction in the presence of calcium salts for periods ranging from 6 to 48 h. The results showed that cell removal was achieved after 12 h, with swelling and negative charge increasing with processing time. Nevertheless, collagen fibril structure, ability to form fibrils, and stability to collagenase were progressive after 24-h processing. There was no denaturation of the collagen matrix. A process is described for the preparation of acellular bovine pericardium matrices with preserved fibril structure and morphology for the manufacture of cardiac valve bioprostheses and may be used in other applications for tissue reconstruction.

  7. Preparation and characterization of an acellular bovine pericardium intended for manufacture of valve bioprostheses.

    PubMed

    Goissis, Gilberto; Giglioti, Aparecida de Fátima; Braile, Domingo Marcolino

    2011-05-01

    Major problems with biological heart valves post-implantation are associated with progressive structural deterioration and calcification attributed to glutaraldehyde processing, dead cells, and cell fragments present in the native tissue. In spite of these problems, glutaraldehyde still is the reagent of choice. The results with acellular matrix xenograft usually prepared by detergent treatment in association with enzymes are rather conflicting because while preserving mechanical properties, tissue morphology and collagen structure are process dependent. This work describes a chemical approach for the preparation of an acellular bovine pericardium matrix intended for the manufacture of heart valve bioprostheses. Cell removal was performed by an alkaline extraction in the presence of calcium salts for periods ranging from 6 to 48 h. The results showed that cell removal was achieved after 12 h, with swelling and negative charge increasing with processing time. Nevertheless, collagen fibril structure, ability to form fibrils, and stability to collagenase were progressive after 24-h processing. There was no denaturation of the collagen matrix. A process is described for the preparation of acellular bovine pericardium matrices with preserved fibril structure and morphology for the manufacture of cardiac valve bioprostheses and may be used in other applications for tissue reconstruction. PMID:21595716

  8. Strontium-calcium coadministration stimulates bone matrix osteogenic factor expression and new bone formation in a large animal model.

    PubMed

    Li, Zhaoyang; Lu, William W; Chiu, Peter K Y; Lam, Raymond W M; Xu, Bing; Cheung, Kenneth M C; Leong, John C Y; Luk, Keith D K

    2009-06-01

    Strontium (Sr) has become increasingly attractive for use in the prevention and treatment of osteoporosis by concomitantly inhibiting bone resorption and enhancing bone formation. Strontium shares similar chemical, physical, and biological characteristics with calcium (Ca), which has been widely used as a dietary supplement in osteoporosis. However, the effects of Sr-Ca coadministration on bone growth and remodeling are yet to be extensively reported. In this study, 18 ovariectomized goats were divided into four groups: three groups of five goats each treated with 100 mg/kg/day Ca, Ca plus 24 mg/kg/day Sr (Ca + 24Sr), or Ca plus 40 mg/kg/day Sr (Ca + 40Sr), and three untreated goats fed low calcium feed. Serum Sr levels increased 6- and 10-fold in the Ca + 24Sr and Ca + 40Sr groups, respectively. Similarly, Sr in the bone increased four- and sixfold in these two groups. Sr-Ca coadministration considerably increased bone mineral apposition rate (MAR). The expression of insulin-like growth factor (IGF)-1 and runt-related transcription factor 2 (Runx2) was significantly upregulated within the Ca + 40Sr treatment group; tumor necrosis factor (TNF)-agr; expression was significantly downregulated in the Ca and Ca + 40Sr groups. The results indicate that Sr-Ca coadministration increases osteogenic gene expression and stimulates new bone formation. PMID:19025756

  9. Cementum-like matrix in solitary bone cysts: a unique and characteristic but yet underrecognized feature of promising diagnostic utility.

    PubMed

    Tariq, Muhammad Usman; Din, Nasir Ud; Ahmad, Zubair; Kayani, Naila; Ahmed, Rashida

    2014-02-01

    Solitary bone cysts (SBCs) are benign, intraosseus, cystic lesions, which generally involve metaphysis of long bones during the period of skeletal immaturity. Histologic features are nonspecific, but identification of amorphous cementum-like material provides a significant diagnostic clue. This material is unique to SBC with reported frequency of 10% to 70% and has been described as an immature form of bone. We retrieved and reviewed 41 cases of SBC reported in the last 10 years. The ages of patients ranged from 4 to 64 years (mean, 16 years), with a male-to-female ratio of 3:1. Humerus and femur were the most common sites. Cementum-like matrix was observed in 26 cases (63.4%). This material was seen in different phases of deposition and progression, ultimately transforming into mature bone as seen in 4 cases. Cyst wall lining was observed in 70.7% of cases along with several other nonspecific histologic features including reactive bone formation, hemosiderin macrophages, hemorrhage, multinucleated giant cells, foamy macrophages, fibrin, cholesterol clefts, and granulation tissue. Cementum-like material in the wall of SBCs is a specific and fairly consistent finding of diagnostic significance in cases where cyst wall lining is deficient. We also histologically demonstrate, for the first time, transformation of cementum-like material into reactive and mature bone, which further validates the immature osteoid nature and finding of other authors.

  10. The osteogenetic efficacy of goat bone marrow-enriched self-assembly peptide/demineralized bone matrix in vitro and in vivo.

    PubMed

    Li, Zhiqiang; Hou, Tianyong; Deng, Moyuan; Luo, Fei; Wu, Xuehui; Xing, Junchao; Chang, Zhengqi; Xu, Jianzhong

    2015-04-01

    In clinical practice, the prolonged duration, high cost, critical technique requirements, and ethical issues make the classical construction method of tissue-engineered bones difficult to apply widely. The major essentials in tissue engineering strategies include seed cells, growth factors, and scaffolds. This study aimed to incorporate these factors in a rapid and cost-effective manner. A self-assembly peptide/demineralized bone matrix (SAP/DBM) composite was artificially established and used for bone marrow enrichment via a selective cell retention approach. Then, goat mesenchymal stem cells (gMSCs) were seeded onto the SAP/DBM or DBM. The proliferation status of gMSCs in different scaffolds was analyzed, and the osteogenetic efficacy was evaluated after osteogenic induction. Bilateral critical-sized femoral defects (20-mm in length) were created in goats, and then the defects were implanted with the postenriched composite or DBM. Then, bone scan imaging, micro-computed tomography (CT) analysis and histological examination were performed to assess the reparative effects of the different implants. Compared with the DBM scaffolds, the growth of gMSCs in the postenriched SAP/DBM composite was faster and the expression levels of the osteo-specific genes (i.e., alkaline phosphatase, osteocalcin, osteopontin, and runt-related transcription factor 2) were significantly higher after 14 days of osteogenic induction. More importantly, the postenriched SAP/DBM composite significantly enhanced bone metabolic activity in the defect area compared with DBM at 2 and 4 weeks postoperation. Moreover, bone reconstruction was complete in marrow-enriched SAP/DBM composite, but not in the DBM. In addition, all of the osteo-related parameters, including the ratio of bone volume to total bone volume, bone mineral density, new trabecular number, and new trabecular thickness, were significantly higher in the marrow-enriched SAP/DBM than those in the DBM. These results indicated that the

  11. Development and characterization of acellular porcine pulmonary valve scaffolds for tissue engineering.

    PubMed

    Luo, Ji; Korossis, Sotirios A; Wilshaw, Stacy-Paul; Jennings, Louise M; Fisher, John; Ingham, Eileen

    2014-11-01

    Currently available replacement heart valves all have limitations. This study aimed to produce and characterize an acellular, biocompatible porcine pulmonary root conduit for reconstruction of the right ventricular outflow tract e.g., during Ross procedure. A process for the decellularization of porcine pulmonary roots was developed incorporating trypsin treatment of the adventitial surface of the scraped pulmonary artery and sequential treatment with hypotonic Tris buffer (HTB; 10 mM Tris pH 8.0, 0.1% (w/v) EDTA, and 10 KIU aprotinin), 0.1% (w/v) sodium dodecyl sulfate in HTB, two cycles of DNase and RNase, and sterilization with 0.1% (v/v) peracetic acid. Histology confirmed an absence of cells and retention of the gross histoarchitecture. Immunohistochemistry further confirmed cell removal and partial retention of the extracellular matrix, but a loss of collagen type IV. DNA levels were reduced by more than 96% throughout all regions of the acellular tissue and no functional genes were detected using polymerase chain reaction. Total collagen levels were retained but there was a significant loss of glycosaminoglycans following decellularization. The biomechanical, hydrodynamic, and leaflet kinematics properties were minimally affected by the process. Both immunohistochemical labeling and antibody absorption assay confirmed a lack of α-gal epitopes in the acellular porcine pulmonary roots and in vitro biocompatibility studies indicated that acellular leaflets and pulmonary arteries were not cytotoxic. Overall the acellular porcine pulmonary roots have excellent potential for development of a tissue substitute for right ventricular outflow tract reconstruction e.g., during the Ross procedure. PMID:24786313

  12. Ultrastructural and mineral phase characterization of the bone-like matrix assembled in F-OST osteoblast cultures.

    PubMed

    Querido, W; Abraçado, L G; Rossi, A L; Campos, A P C; Rossi, A M; San Gil, R A S; Borojevic, R; Balduino, A; Farina, M

    2011-11-01

    Cell cultures are often used to study bone mineralization; however, not all systems achieve a bone-like matrix formation. In this study, the mineralized matrix assembled in F-OST osteoblast cultures was analyzed, with the aim of establishing a novel model for bone mineralization. The ultrastructure of the cultures was investigated using scanning electron microscopy, atomic force microscopy, and transmission electron microscopy (TEM). The mineral phase was characterized using conventional and high-resolution TEM, energy-dispersive X-ray spectroscopy, X-ray diffraction, Fourier transform infrared spectroscopy, and solid-state (31)P and (1)H nuclear magnetic resonance. F-OST osteoblast cultures presented a clear nodular mineralization pattern. The chief features of the mineralizing nodules were globular accretions ranging from about 100 nm to 1.5 μm in diameter, loaded with needle-shaped crystallites. Accretions seemed to bud from the cell membrane, increase in size, and coalesce into larger ones. Arrays of loosely packed, randomly oriented collagen fibrils were seen along with the accretions. Mineralized fibrils were often observed, sometimes in close association with accretions. The mineral phase was characterized as a poorly crystalline hydroxyapatite. The Ca/P atomic ratio was 1.49 ± 0.06. The presence of OH was evident. The lattice parameters were a = 9.435 Å and c = 6.860 Å. The average crystallite size was 20 nm long and 10 nm wide. Carbonate substitutions were seen in phosphate and OH sites. Water was also found within the apatitic core. In conclusion, F-OST osteoblast cultures produce a bone-like matrix and may provide a good model for bone mineralization studies.

  13. The effect of glass-ceramic implants on matrix vesicle calcification after two weeks of rat tibial bone healing.

    PubMed

    Müller-Mai, C; Amir, D; Wendland, H; Schwartz, Z; Sela, J; Gross, U

    1990-12-01

    Type, size and distribution of extracellular matrix vesicles (MV), known mediators of primary calcification, were studied around bone-bonding and metal-oxide containing, nonbonding, glass-ceramic implants. This was performed in order to further understand the different effects of implants on bone healing. At 14 days after implantation in adult rat tibial bone the effects of different implants on MV were studied by transmission electron microscopy and computerized morphometry. A total number of 4607 MV in 245 electron micrographs were counted and grouped according to diameter, distance from the calcifying front, and classified as four types: "empty," "amorphous," "crystal," and "rupture." The sequence of types according to diameter and distance was recorded as follows around both implants tested: "rupture" MV were the closest to the front with the largest diameter, followed by "crystal," "amorphous," and "empty," MV with the largest distance from the front and the smallest diameter. Most vesicles were concentrated in a distance of less than 2.4 microns from the front and between diameters of 0.06 microns and 0.22 microns. The noncalcified extracellular matrix around bone-bonding implants contained more MV than the matrix around the nonbonding type (26.24 MV/10 microns2 and 18.76 MV/10 microns2). MV distribution according to types showed that around bonding implants there was a higher percentage of "crystal" and a lower percentage of "rupture" when compared to the nonbonding type. These results indicate that bonding implants affect osteoblastic function by increasing the vesicular number and retardation of intravesicular crystal formation. It might be suggested that bonding implants induce an increase in the process of primary calcification and a decreased rate of crystal formation resulting with the highest organization of the healing bone.

  14. Combination of absorbable mesh and demineralized bone matrix in orbital wall fracture for preventing herniation of orbit.

    PubMed

    Tak, Kyoung Seok; Jung, Min Su; Lee, Byeong Ho; Kim, Joo Hyun; Ahn, Duk Kyun; Jeong, Hii Sun; Park, Young Kyu; Suh, In Suck

    2014-07-01

    After restoration of orbit wall fracture, preventing sequelae is important. An absorbable mesh is commonly used in orbit wall fracture, yet it has limitation due to orbit sagging when bony defect is larger than the moderate size (1 × 1 cm2). In this study, the authors present a satisfactory result in treating orbit wall fracture larger than the moderate size with a combination of absorbable mesh and demineralized bone matrix.From 2009 to 2012, 63 patients with bony defect larger than the moderate size, who were treated with a combination of absorbable mesh and demineralized bone matrix, were reviewed retrospectively. The site of bony defect, size, and applied amount of demineralized bone matrix were reviewed, and a 2-year follow-up was done. Facial computed tomography scans were checked preoperative, immediate postoperative, and 2-year postoperative.Among the 63 patients, there were 52 men and 11 women. Mean age was 33.3 years. The most common cause was blunt blow (35 cases); mean defect size was 13.36 × 12.82 mm2 in inferior wall fracture and 20.69 × 14.41 mm2 in medial wall fracture. There was no complication except for 3 cases of infraorbital nerve hypoesthesia. A 2-year follow-up computed tomography showed that the surgical site preserved bony formation without herniation. In treating moderate-sized bony defect in orbit wall fracture, absorbable mesh and demineralized bone matrix can maintain structural stability through good bony formation even after degradation of absorbable mesh.

  15. Matched Comparison of Fusion Rates between Hydroxyapatite Demineralized Bone Matrix and Autograft in Lumbar Interbody Fusion

    PubMed Central

    Kim, Dae Hwan; Lee, Nam; Shin, Dong Ah; Yi, Seong; Kim, Keung Nyun

    2016-01-01

    Objective To compare the fusion rate of a hydroxyapatite demineralized bone matrix (DBM) with post-laminectomy acquired autograft in lumbar interbody fusion surgery and to evaluate the correlation between fusion rate and clinical outcome. Methods From January 2013 to April 2014, 98 patients underwent lumbar interbody fusion surgery with hydroxyapatite DBM (HA-DBM group) in our institute. Of those patients, 65 received complete CT scans for 12 months postoperatively in order to evaluate fusion status. For comparison with autograft, we selected another 65 patients who underwent lumbar interbody fusion surgery with post-laminectomy acquired autograft (Autograft group) during the same period. Both fusion material groups were matched in terms of age, sex, body mass index (BMI), and bone mineral density (BMD). To evaluate the clinical outcomes, we analyzed the results of visual analogue scale (VAS), Oswestry Disability Index (ODI), and Short Form Health Survey (SF-36). Results We reviewed the CT scans of 149 fusion levels in 130 patients (HA-DBM group, 75 levels/65 patients; Autograft group, 74 levels/65 patients). Age, sex, BMI, and BMD were not significantly different between the groups (p=0.528, p=0.848, p=0.527, and p=0.610, respectively). The HA-DBM group showed 39 of 75 fused levels (52%), and the Autograft group showed 46 of 74 fused levels (62.2%). This difference was not statistically significant (p=0.21). In the HA-DBM group, older age and low BMD were significantly associated with non-fusion (61.24 vs. 66.68, p=0.027; -1.63 vs. -2.29, p=0.015, respectively). VAS and ODI showed significant improvement after surgery when fusion was successfully achieved in both groups (p=0.004, p=0.002, HA-DBM group; p=0.012, p=0.03, Autograft group). Conclusion The fusion rates of the hydroxyapatite DBM and Autograft groups were not significantly different. In addition, clinical outcomes were similar between the groups. However, older age and low BMD are risk factors that might

  16. Cartilage tissue engineering of nasal septal chondrocyte-macroaggregates in human demineralized bone matrix.

    PubMed

    Liese, Juliane; Marzahn, Ulrike; El Sayed, Karym; Pruss, Axel; Haisch, Andreas; Stoelzel, Katharina

    2013-06-01

    Tissue Engineering is an important method for generating cartilage tissue with isolated autologous cells and the support of biomaterials. In contrast to various gel-like biomaterials, human demineralized bone matrix (DBM) guarantees some biomechanical stability for an application in biomechanically loaded regions. The present study combined for the first time the method of seeding chondrocyte-macroaggregates in DBM for the purpose of cartilage tissue engineering. After isolating human nasal chondrocytes and creating a three-dimensional macroaggregate arrangement, the DBM was cultivated in vitro with the macroaggregates. The interaction of the cells within the DBM was analyzed with respect to cell differentiation and the inhibitory effects of chondrocyte proliferation. In contrast to chondrocyte-macroaggregates in the cell-DBM constructs, morphologically modified cells expressing type I collagen dominated. The redifferentiation of chondrocytes, characterized by the expression of type II collagen, was only found in low amounts in the cell-DBM constructs. Furthermore, caspase 3, a marker for apoptosis, was detected in the chondrocyte-DBM constructs. In another experimental setting, the vitality of chondrocytes as related to culture time and the amount of DBM was analyzed with the BrdU assay. Higher amounts of DBM tended to result in significantly higher proliferation rates of the cells within the first 48 h. After 96 h, the vitality decreased in a dose-dependent fashion. In conclusion, this study provides the proof of concept of chondrocyte-macroaggregates with DBM as an interesting method for the tissue engineering of cartilage. The as-yet insufficient redifferentiation of the chondrocytes and the sporadic initiation of apoptosis will require further investigations.

  17. Prosthetic Breast Reconstruction With Acellular Dermal Matrices: Achieving Predictability and Reproducibility.

    PubMed

    Nahabedian, Maurice Y

    2016-05-01

    The use of acellular dermal matrices in the setting of prosthetic breast reconstruction has captured the attention of many plastic surgeons. The regenerative capacity of these materials has provided additional tissue support to the mastectomy skin flaps with the ultimate result of improving surgical and aesthetic outcomes. Despite the benefits, there remains a significant diversity with regard to outcomes with some surgeons reporting increased morbidity. The reasons for this are varied but ultimately related to differences in patient selection and surgical techniques. The purpose of this article is to provide strategies for using acellular dermal matrix to achieve success in a manner that is usually associated with outcomes that are predictable and reproducible. PMID:27579223

  18. Prosthetic Breast Reconstruction With Acellular Dermal Matrices: Achieving Predictability and Reproducibility

    PubMed Central

    2016-01-01

    Summary: The use of acellular dermal matrices in the setting of prosthetic breast reconstruction has captured the attention of many plastic surgeons. The regenerative capacity of these materials has provided additional tissue support to the mastectomy skin flaps with the ultimate result of improving surgical and aesthetic outcomes. Despite the benefits, there remains a significant diversity with regard to outcomes with some surgeons reporting increased morbidity. The reasons for this are varied but ultimately related to differences in patient selection and surgical techniques. The purpose of this article is to provide strategies for using acellular dermal matrix to achieve success in a manner that is usually associated with outcomes that are predictable and reproducible. PMID:27579223

  19. Altered bone material properties in HLA-B27 rats include reduced mineral to matrix ratio and altered collagen cross-links.

    PubMed

    Gamsjaeger, Sonja; Srivastava, Apurva K; Wergedal, Jon E; Zwerina, Jochen; Klaushofer, Klaus; Paschalis, Eleftherios P; Tatakis, Dimitris N

    2014-11-01

    Spondyloarthropathy and inflammatory bowel disease (IBD), which includes ulcerative colitis and Crohn's disease, are often associated with severe osteopenia/osteoporosis in both children and adults. HLA-B27 transgenic rats present a phenotype that includes severe colitis and severely accelerated alveolar bone loss. The purpose of this study was to evaluate long bone density status, systemic bone metabolic markers, and intrinsic bone material properties in HLA-B27 transgenic (TG) rats, and compare them with those of age- and sex-matched wild-type (WT) animals. The results indicate that in the HLA-B27 rat, an animal susceptible to both alveolar bone loss (ABL) and long bone osteopenia, there is a statistically significant negative correlation between ABL and long bone bone mineral density (BMD), as well as mineral/matrix ratio at active bone-forming trabecular surfaces. The TG animals had a lower mineral/matrix ratio and higher relative proteoglycan and advanced glycation end product (ϵ-N-Carboxymethyl-L-lysine) content and pyridinoline/divalent collagen cross-link ratio compared with WT. These results may provide better understanding of the interrelationship between osteoporosis and oral bone loss, the underlying causes of the inferior bone strength in the HLA-B27 transgenic animals, and could prove to be a useful model in the elucidation of the pathophysiology of spondyloarthropathy and IBD-associated osteopenia/osteoporosis and in the evaluation of pharmacological intervention(s) against such conditions. PMID:24771481

  20. Bone-demineralization diagnosis in a bone-tissue-skin matrix using the pulsed-chirped photothermal radar

    NASA Astrophysics Data System (ADS)

    Kaiplavil, Sreekumar; Mandelis, Andreas

    2012-02-01

    A chirped pulsed photothermal radiometric radar is introduced for the diagnosis of biological samples, especially bones with tissue and skin overlayers. The constraints imposed by the laser safety (maximum permissible exposure, MPE) ceiling on pump laser energy and the strong attenuation of thermal-wave signals in tissues significantly limit the photothermally active depth in most biological specimens to a level which is normally insufficient for practical applications (approx. 1 mm below the skin surface). A theoretical approach for improvement of signal-to-noise ratio (SNR), minimizing the static (dc) component of the photothermal signal and making use of the photothermal radiometric nonlinearity has been introduced and verified by comparing the SNR of four distinct excitation wave forms (sine-wave, square-wave, constant- width and constant duty-cycle pulses) for chirping the pump laser, under constant exposure energy. At low frequencies fixed-pulsewidth chirps of large peak power were found to be superior to all other equal-energy modalities, with an SNR improvement up to two orders of magnitude. Distinct thickness-dependent characteristic delay times in a goat bone were obtained, establishing an active depth resolution range of ca. 2.8 mm in a layered skin-fat- bone structure, a favorable result compared to the maximum reported pulsed photothermal radiometric depth resolution < 1 mm in turbid biological media. Compared to radar peak delay and amplitude, the long-delayed radar output amplitude is found to be more sensitive to subsurface conditions. Two-dimensional spatial plots of this parameter depicting the back surface conditions of bones with and without fat-tissue overlayers are presented.

  1. Acellularization-Induced Changes in Tensile Properties Are Organ Specific - An In-Vitro Mechanical and Structural Analysis of Porcine Soft Tissues

    PubMed Central

    Aust, Gabriela; Boldt, Andreas; Fritsch, Sebastian; Keil, Isabel; Koch, Holger; Möbius, Robert; Scheidt, Holger A.; Wagner, Martin F. X.; Hammer, Niels

    2016-01-01

    Introduction Though xenogeneic acellular scaffolds are frequently used for surgical reconstruction, knowledge of their mechanical properties is lacking. This study compared the mechanical, histological and ultrastructural properties of various native and acellular specimens. Materials and Methods Porcine esophagi, ureters and skin were tested mechanically in a native or acellular condition, focusing on the elastic modulus, ultimate tensile stress and maximum strain. The testing protocol for soft tissues was standardized, including the adaption of the tissue’s water content and partial plastination to minimize material slippage as well as templates for normed sample dimensions and precise cross-section measurements. The native and acellular tissues were compared at the microscopic and ultrastructural level with a focus on type I collagens. Results Increased elastic modulus and ultimate tensile stress values were quantified in acellular esophagi and ureters compared to the native condition. In contrast, these values were strongly decreased in the skin after acellularization. Acellularization-related decreases in maximum strain were found in all tissues. Type I collagens were well-preserved in these samples; however, clotting and a loss of cross-linking type I collagens was observed ultrastructurally. Elastins and fibronectins were preserved in the esophagi and ureters. A loss of the epidermal layer and decreased fibronectin content was present in the skin. Discussion Acellularization induces changes in the tensile properties of soft tissues. Some of these changes appear to be organ specific. Loss of cross-linking type I collagen may indicate increased mechanical strength due to decreasing transverse forces acting upon the scaffolds, whereas fibronectin loss may be related to decreased load-bearing capacity. Potentially, the alterations in tissue mechanics are linked to organ function and to the interplay of cells and the extracellular matrix, which is different in

  2. The effects of chronic hypoperfusion on rat cranial bone mineral and organic matrix. A Fourier transform infrared spectroscopy study.

    PubMed

    Boyar, Handan; Zorlu, Faruk; Mut, Melike; Severcan, Feride

    2004-06-01

    Arteriovenous malformations (AVM) of the brain, errors in the development of the vasculature, produce high flow arteriovenous shunts. They steal blood from surrounding brain tissue, which is chronically hypoperfused. Hypoperfusion is a condition of inadequate tissue perfusion and oxygenation resulting in abnormal tissue metabolism. In the present study Fourier transform infrared (FTIR) spectroscopy was used to investigate the effects of hypoperfusion on rat cranial bone mineral and organic matrix at the molecular level. FTIR spectroscopic analysis revealed that in cranial bones of an experimental group the relative amount of carbonate and phosphate groups increased whereas that of protein (amide I) decreased. Curve-fitting analysis of the v(2) carbonate band showed that amounts of type A and type B carbonates increased slightly ( p=0.423 for both) whereas, type L carbonate decreased slightly ( p=0.522) in hypoperfused cranial bones. Analysis of the C-H region revealed a significant increase ( p=0.037) in the lipid to protein ratio. Because the lipid content is high, hypoperfused cranial bone tissue is more prone to lipid peroxidation. Dialdehydes derived from lipid peroxidation can make cross-links with collagen and might lead to disturbances in the collagen cross-link profile. The 1660 cm(-1)/1690 cm(-1) partial area ratio derived from curve-fitting analysis of the Amide I band is sensitive to the relative amount of collagen non-reducible cross-link hydroxylysyl/lysylpyridinolines (Pyr) and reducible cross-link dihydroxylysinonorleucine (DHLNL) and this ratio reflects collagen maturity. In chronic hypoperfusion a significant decrease ( p=0.004) was observed in this ratio. This means there were less mature collagen cross-links. Disturbances in the collagen maturation can affect mineralization process and lead to formation of pathologic structures in cranial bones. These findings clearly demonstrate that FTIR spectroscopy can be used to extract valuable information

  3. Implications of combined ovariectomy and glucocorticoid (dexamethasone) treatment on mineral, microarchitectural, biomechanical and matrix properties of rat bone.

    PubMed

    Govindarajan, Parameswari; Khassawna, Thaqif; Kampschulte, Marian; Böcker, Wolfgang; Huerter, Britta; Dürselen, Lutz; Faulenbach, Miriam; Heiss, Christian

    2013-12-01

    Osteoporosis is one of the deleterious side effects of long-term glucocorticoid therapy. Since the condition is particularly aggressive in postmenopausal women who are on steroid therapy, in this study we have attempted to analyse the combined effect of glucocorticoid (dexamethasone) treatment and cessation of oestrogen on rat bone. The dual aim was to generate osteoporotic bone status in a short time scale and to characterise the combination of glucocorticoid-postmenopausal osteoporotic conditions. Sprague Dawley rats (N = 42) were grouped randomly into three groups: untreated control, sham-operated and ovariectomized-steroid (OVX-Steroid) rats. Control animals were euthanized with no treatment [Month 0 (M0)], while sham and OVX-Steroid rats were monitored up to 1 month (M1) and 3 months (M3) post laparotomy/post OVX-Steroid treatment. Histology, dual-energy X-ray absorptiometry (DXA), micro-computed tomography (micro-CT), and biomechanical and mRNA expression analysis of collagenous, non-collagenous matrix proteins and osteoclast markers were examined. The study indicated enhanced osteoclastogenesis and significantly lower bone mineral density (BMD) in the OVX-Steroid rats with Z-scores below -2.5, reduced torsional strength, reduced bone volume (BV/TV%), significantly enhanced trabecular separation (Tb.S), and less trabecular number (Tb.N) compared with sham rats. Osteoclast markers, cathepsin K and MMP 9 were upregulated along with Col1α1 and biglycan with no significant expression variation in fibronectin, MMP 14, LRP-5, Car II and TNC. These results show higher bone turnover with enhanced bone resorption accompanied with reduced torsional strength in OVX-Steroid rats; and these changes were attained within a short timeframe. This could be a useful model which mimics human postmenopausal osteoporosis that is associated with steroid therapy and could prove of value both in disease diagnosis and for testing generating and testing biological agents which could

  4. A composite scaffold of MSC affinity peptide-modified demineralized bone matrix particles and chitosan hydrogel for cartilage regeneration

    NASA Astrophysics Data System (ADS)

    Meng, Qingyang; Man, Zhentao; Dai, Linghui; Huang, Hongjie; Zhang, Xin; Hu, Xiaoqing; Shao, Zhenxing; Zhu, Jingxian; Zhang, Jiying; Fu, Xin; Duan, Xiaoning; Ao, Yingfang

    2015-12-01

    Articular cartilage injury is still a significant challenge because of the poor intrinsic healing potential of cartilage. Stem cell-based tissue engineering is a promising technique for cartilage repair. As cartilage defects are usually irregular in clinical settings, scaffolds with moldability that can fill any shape of cartilage defects and closely integrate with the host cartilage are desirable. In this study, we constructed a composite scaffold combining mesenchymal stem cells (MSCs) E7 affinity peptide-modified demineralized bone matrix (DBM) particles and chitosan (CS) hydrogel for cartilage engineering. This solid-supported composite scaffold exhibited appropriate porosity, which provided a 3D microenvironment that supports cell adhesion and proliferation. Cell proliferation and DNA content analysis indicated that the DBM-E7/CS scaffold promoted better rat bone marrow-derived MSCs (BMMSCs) survival than the CS or DBM/CS groups. Meanwhile, the DBM-E7/CS scaffold increased matrix production and improved chondrogenic differentiation ability of BMMSCs in vitro. Furthermore, after implantation in vivo for four weeks, compared to those in control groups, the regenerated issue in the DBM-E7/CS group exhibited translucent and superior cartilage-like structures, as indicated by gross observation, histological examination, and assessment of matrix staining. Overall, the functional composite scaffold of DBM-E7/CS is a promising option for repairing irregularly shaped cartilage defects.

  5. A composite scaffold of MSC affinity peptide-modified demineralized bone matrix particles and chitosan hydrogel for cartilage regeneration.

    PubMed

    Meng, Qingyang; Man, Zhentao; Dai, Linghui; Huang, Hongjie; Zhang, Xin; Hu, Xiaoqing; Shao, Zhenxing; Zhu, Jingxian; Zhang, Jiying; Fu, Xin; Duan, Xiaoning; Ao, Yingfang

    2015-12-03

    Articular cartilage injury is still a significant challenge because of the poor intrinsic healing potential of cartilage. Stem cell-based tissue engineering is a promising technique for cartilage repair. As cartilage defects are usually irregular in clinical settings, scaffolds with moldability that can fill any shape of cartilage defects and closely integrate with the host cartilage are desirable. In this study, we constructed a composite scaffold combining mesenchymal stem cells (MSCs) E7 affinity peptide-modified demineralized bone matrix (DBM) particles and chitosan (CS) hydrogel for cartilage engineering. This solid-supported composite scaffold exhibited appropriate porosity, which provided a 3D microenvironment that supports cell adhesion and proliferation. Cell proliferation and DNA content analysis indicated that the DBM-E7/CS scaffold promoted better rat bone marrow-derived MSCs (BMMSCs) survival than the CS or DBM/CS groups. Meanwhile, the DBM-E7/CS scaffold increased matrix production and improved chondrogenic differentiation ability of BMMSCs in vitro. Furthermore, after implantation in vivo for four weeks, compared to those in control groups, the regenerated issue in the DBM-E7/CS group exhibited translucent and superior cartilage-like structures, as indicated by gross observation, histological examination, and assessment of matrix staining. Overall, the functional composite scaffold of DBM-E7/CS is a promising option for repairing irregularly shaped cartilage defects.

  6. A composite scaffold of MSC affinity peptide-modified demineralized bone matrix particles and chitosan hydrogel for cartilage regeneration

    PubMed Central

    Meng, Qingyang; Man, Zhentao; Dai, Linghui; Huang, Hongjie; Zhang, Xin; Hu, Xiaoqing; Shao, Zhenxing; Zhu, Jingxian; Zhang, Jiying; Fu, Xin; Duan, Xiaoning; Ao, Yingfang

    2015-01-01

    Articular cartilage injury is still a significant challenge because of the poor intrinsic healing potential of cartilage. Stem cell-based tissue engineering is a promising technique for cartilage repair. As cartilage defects are usually irregular in clinical settings, scaffolds with moldability that can fill any shape of cartilage defects and closely integrate with the host cartilage are desirable. In this study, we constructed a composite scaffold combining mesenchymal stem cells (MSCs) E7 affinity peptide-modified demineralized bone matrix (DBM) particles and chitosan (CS) hydrogel for cartilage engineering. This solid-supported composite scaffold exhibited appropriate porosity, which provided a 3D microenvironment that supports cell adhesion and proliferation. Cell proliferation and DNA content analysis indicated that the DBM-E7/CS scaffold promoted better rat bone marrow-derived MSCs (BMMSCs) survival than the CS or DBM/CS groups. Meanwhile, the DBM-E7/CS scaffold increased matrix production and improved chondrogenic differentiation ability of BMMSCs in vitro. Furthermore, after implantation in vivo for four weeks, compared to those in control groups, the regenerated issue in the DBM-E7/CS group exhibited translucent and superior cartilage-like structures, as indicated by gross observation, histological examination, and assessment of matrix staining. Overall, the functional composite scaffold of DBM-E7/CS is a promising option for repairing irregularly shaped cartilage defects. PMID:26632447

  7. Characteristics and response of mouse bone marrow derived novel low adherent mesenchymal stem cells acquired by quantification of extracellular matrix

    PubMed Central

    Zheng, Ri-Cheng; Heo, Seong-Joo; Koak, Jai-Young; Lee, Joo-Hee; Park, Ji-Man

    2014-01-01

    PURPOSE The aim of present study was to identify characteristic and response of mouse bone marrow (BM) derived low-adherent bone marrow mesenchymal stem cells (BMMSCs) obtained by quantification of extracellular matrix (ECM). MATERIALS AND METHODS Non-adherent cells acquired by ECM coated dishes were termed low-adherent BMMSCs and these cells were analyzed by in vitro and in vivo methods, including colony forming unit fibroblast (CFU-f), bromodeoxyuridine (BrdU), multi-potential differentiation, flow cytometry and transplantation into nude mouse to measure the bone formation ability of these low-adherent BMMSCs. Titanium (Ti) discs with machined and anodized surfaces were prepared. Adherent and low-adherent BMMSCs were cultured on the Ti discs for testing their proliferation. RESULTS The amount of CFU-f cells was significantly higher when non-adherent cells were cultured on ECM coated dishes, which was made by 7 days culturing of adherent BMMSCs. Low-adherent BMMSCs had proliferation and differentiation potential as adherent BMMSCs in vitro. The mean amount bone formation of adherent and low-adherent BMMSCs was also investigated in vivo. There was higher cell proliferation appearance in adherent and low-adherent BMMSCs seeded on anodized Ti discs than machined Ti discs by time. CONCLUSION Low-adherent BMMSCs acquired by ECM from non-adherent cell populations maintained potential characteristic similar to those of the adherent BMMSCs and therefore could be used effectively as adherent BMMSCs in clinic. PMID:25352957

  8. The enigmas of bone without osteocytes

    PubMed Central

    Shahar, Ron; Dean, Mason N

    2013-01-01

    One of the hallmarks of tetrapod bone is the presence of numerous cells (osteocytes) within the matrix. Osteocytes are vital components of tetrapod bone, orchestrating the processes of bone building, reshaping and repairing (modeling and remodeling), and probably also participating in calcium-phosphorus homeostasis via both the local process of osteocytic osteolysis, and systemic effect on the kidneys. Given these critical roles of osteocytes, it is thought-provoking that the entire skeleton of many fishes consists of bone material that does not contain osteocytes. This raises the intriguing question of how the skeleton of these animals accomplishes the various essential functions attributed to osteocytes in other vertebrates, and raises the possibility that in acellular bone some of these functions are either accomplished by non-osteocytic routes or not necessary at all. In this review, we outline evidence for and against the fact that primary functions normally ascribed to osteocytes, such as mechanosensation, regulation of osteoblast/clast activity and mineral metabolism, also occur in fish bone devoid of these cells, and therefore must be carried out through alternative and perhaps ancient pathways. To enable meaningful comparisons with mammalian bone, we suggest thorough, phylogenetic examinations of regulatory pathways, studies of structure and mechanical properties and surveys of the presence/absence of bone cells in fishes. Insights gained into the micro-/nanolevel structure and architecture of fish bone, its mechanical properties and its physiology in health and disease will contribute to the discipline of fish skeletal biology, but may also help answer questions of basic bone biology. PMID:24422081

  9. Bone matrix structure in different seasons of cervid antlerogenesis and gestation

    NASA Astrophysics Data System (ADS)

    Silvennoinen, Raimo V. J.; Nygren, Kaarlo; Rouvinen, Juha; Petrova, Valentina V.

    1994-05-01

    During the antlerogenesis and gestation, substantial amounts of mineral compounds are removed from the skeleton and transferred to the growing antler or foetus. We have used holographic nondestructive testing for sorting out biomechanically aberrant radioulnar bones of European moose and radiological methods to study, whether observed aberrations are due to changes of the structure of the long bones (radius). In males, these changes were studied in three phases of antler cycle: antlerless season, antler growing and mature antler. In females, the studies were made with samples of adult individuals in and after gestation period. We studied x-ray diffraction responses of the bones before and after compression up to saturation level. Our results are indicating that compact and spongy part of the bones are giving seasonally different biomechanical responses.

  10. Osteogenesis effect of guided bone regeneration combined with alveolar cleft grafting: assessment by cone beam computed tomography.

    PubMed

    Xiao, W-L; Zhang, D-Z; Chen, X-J; Yuan, C; Xue, L-F

    2016-06-01

    Cone beam computed tomography (CBCT) allows for a significantly lower radiation dose than conventional computed tomography (CT) scans and provides accurate images of the alveolar cleft area. The osteogenic effect of guided bone regeneration (GBR) vs. conventional alveolar bone grafting alone for alveolar cleft defects was evaluated in this study. Sixty alveolar cleft patients were divided randomly into two groups. One group underwent GBR using acellular dermal matrix film combined with alveolar bone grafting using iliac crest bone grafts (GBR group), while the other group underwent alveolar bone grafting only (non-GBR group). CBCT images were obtained at 1 week and at 3 months following the procedure. Using Simplant 11.04 software, the bone resorption rate was calculated and compared between the two groups. The bone resorption rate from 1 week to 3 months following bone grafting without the GBR technique was 36.50±5.04%, whereas the bone resorption rate using the GBR technique was 31.69±5.50% (P=0.017). The application of autogenous iliac bone combined with the GBR technique for alveolar bone grafting of alveolar cleft patients can reduce bone resorption and result in better osteogenesis.

  11. Osteogenesis effect of guided bone regeneration combined with alveolar cleft grafting: assessment by cone beam computed tomography.

    PubMed

    Xiao, W-L; Zhang, D-Z; Chen, X-J; Yuan, C; Xue, L-F

    2016-06-01

    Cone beam computed tomography (CBCT) allows for a significantly lower radiation dose than conventional computed tomography (CT) scans and provides accurate images of the alveolar cleft area. The osteogenic effect of guided bone regeneration (GBR) vs. conventional alveolar bone grafting alone for alveolar cleft defects was evaluated in this study. Sixty alveolar cleft patients were divided randomly into two groups. One group underwent GBR using acellular dermal matrix film combined with alveolar bone grafting using iliac crest bone grafts (GBR group), while the other group underwent alveolar bone grafting only (non-GBR group). CBCT images were obtained at 1 week and at 3 months following the procedure. Using Simplant 11.04 software, the bone resorption rate was calculated and compared between the two groups. The bone resorption rate from 1 week to 3 months following bone grafting without the GBR technique was 36.50±5.04%, whereas the bone resorption rate using the GBR technique was 31.69±5.50% (P=0.017). The application of autogenous iliac bone combined with the GBR technique for alveolar bone grafting of alveolar cleft patients can reduce bone resorption and result in better osteogenesis. PMID:26876144

  12. Alterations of collagen matrix in weight-bearing bones during skeletal unloading

    NASA Technical Reports Server (NTRS)

    Shiiba, M.; Arnaud, S. B.; Tanzawa, H.; Uzawa, K.; Yamauchi, M.

    2001-01-01

    Skeletal unloading induces loss of bone mineral density in weight-bearing bones. The objectives of this study were to characterize the post-translational modifications of collagen of weight-bearing bones subjected to hindlimb unloading for 8 weeks. In unloaded bones, tibiae and femurs, while the overall amino acid composition was essentially identical in the unloaded and control tibiae and femurs, the collagen cross-link profile showed significant differences. Two major reducible cross-links (analyzed as dihydroxylysinonorleucine and hydroxylysinonorleucine) were increased in the unloaded bones. In addition, the ratios of the former to the latter as well as pyridinoline to deoxypyridinoline were significantly decreased in the unloaded bones indicating a difference in the extent of lysine hydroxylation at the cross-linking sites between these two groups. These results indicate that upon skeletal unloading the relative pool of newly synthesized collagen is increased and it is post-translationally altered. The alteration could be associated with impaired osteoblastic differentiation induced by skeletal unloading that results in a mineralization defect.

  13. ToF-SIMS analysis of osteoblast-like cells and their mineralized extracellular matrix on strontium enriched bone cements.

    PubMed

    Kokesch-Himmelreich, Julia; Schumacher, Matthias; Rohnke, Marcus; Gelinsky, Michael; Janek, Jürgen

    2013-12-01

    Commonly used implants for therapeutic approaches of non-systemically impaired bone do not sufficiently support the healing process of osteoporotic bone. Since strontium (II) has been proven as an effective anti-osteoporotic drug new types of strontium enriched calcium phosphate bone cements were developed. As osteoporosis is characterized by an imbalance of osteoblast and osteoclast activity the influence of this newly generated strontium enriched biomaterials on the cellular behavior of osteoblast-like cells was investigated by time of flight secondary ion mass spectrometry (ToF-SIMS). ToF-SIMS is used to analyze whether strontium is incorporated in the mineralized extracellular matrix (mECM) and whether there is strontium uptake by osteogenically differentiated human mesenchymal stem cells (hMSCs). Therefore hMSCs were cultured in osteogenic differentiation medium for 21 days on two different strontium enriched bone cements (S100 and A10) and for reference also on the pure calcium phosphate cement (CPC) and on a silicon wafer. The distribution of strontium in the osteoblast-like cells and within their mineralized extracellular matrix was analyzed. A higher intensity of the strontium signal could be detected in the region of the mECM, synthesized by cells cultivated on the Sr- substituted bone cement (S100) in comparison to the reference groups. The osteoblast-like cells used the released strontium from the biomaterial to synthesize their mECM. Apart from that a uniform strontium distribution was measured within all investigated cells. However, different amounts of strontium were found in cells cultured on different biomaterials and substrates. Compared to the negative controls the strontium content in the cells on the strontium enriched biomaterials was much higher. A higher concentration of strontium inside the cells means that more strontium can take part in signaling pathways. As strontium is known for its beneficial effects on osteoblasts by promoting

  14. Biomimetic Mineralization on a Macroporous Cellulose-Based Matrix for Bone Regeneration

    PubMed Central

    Petrauskaite, Odeta; Gomes, Pedro de Sousa; Fernandes, Maria Helena; Juodzbalys, Gintaras; Maminskas, Julius

    2013-01-01

    The aim of this study is to investigate the biomimetic mineralization on a cellulose-based porous matrix with an improved biological profile. The cellulose matrix was precalcified using three methods: (i) cellulose samples were treated with a solution of calcium chloride and diammonium hydrogen phosphate; (ii) the carboxymethylated cellulose matrix was stored in a saturated calcium hydroxide solution; (iii) the cellulose matrix was mixed with a calcium silicate solution in order to introduce silanol groups and to combine them with calcium ions. All the methods resulted in a mineralization of the cellulose surfaces after immersion in a simulated body fluid solution. Over a period of 14 days, the matrix was completely covered with hydroxyapatite crystals. Hydroxyapatite formation depended on functional groups on the matrix surface as well as on the precalcification method. The largest hydroxyapatite crystals were obtained on the carboxymethylated cellulose matrix treated with calcium hydroxide solution. The porous cellulose matrix was not cytotoxic, allowing the adhesion and proliferation of human osteoblastic cells. Comparatively, improved cell adhesion and growth rate were achieved on the mineralized cellulose matrices. PMID:24163816

  15. Chemical modification of extracellular matrix by cold atmospheric plasma-generated reactive species affects chondrogenesis and bone formation.

    PubMed

    Eisenhauer, Peter; Chernets, Natalie; Song, You; Dobrynin, Danil; Pleshko, Nancy; Steinbeck, Marla J; Freeman, Theresa A

    2016-09-01

    The goal of this study was to investigate whether cold plasma generated by dielectric barrier discharge (DBD) modifies extracellular matrices (ECM) to influence chondrogenesis and endochondral ossification. Replacement of cartilage by bone during endochondral ossification is essential in fetal skeletal development, bone growth and fracture healing. Regulation of this process by the ECM occurs through matrix remodelling, involving a variety of cell attachment molecules and growth factors, which influence cell morphology and protein expression. The commercially available ECM, Matrigel, was treated with microsecond or nanosecond pulsed (μsp or nsp, respectively) DBD frequencies conditions at the equivalent frequencies (1 kHz) or power (~1 W). Recombinant human bone morphogenetic protein-2 was added and the mixture subcutaneously injected into mice to simulate ectopic endochondral ossification. Two weeks later, the masses were extracted and analysed by microcomputed tomography. A significant increase in bone formation was observed in Matrigel treated with μsp DBD compared with control, while a significant decrease in bone formation was observed for both nsp treatments. Histological and immunohistochemical analysis showed Matrigel treated with μsp plasma increased the number of invading cells, the amount of vascular endothelial growth factor and chondrogenesis while the opposite was true for Matrigel treated with nsp plasma. In support of the in vivo Matrigel study, 10 T1/2 cells cultured in vitro on μsp DBD-treated type I collagen showed increased expression of adhesion proteins and activation of survival pathways, which decreased with nsp plasma treatments. These results indicate DBD modification of ECM can influence cellular behaviours to accelerate or inhibit chondrogenesis and endochondral ossification. Copyright © 2016 John Wiley & Sons, Ltd. PMID:27510797

  16. Chemical modification of extracellular matrix by cold atmospheric plasma-generated reactive species affects chondrogenesis and bone formation.

    PubMed

    Eisenhauer, Peter; Chernets, Natalie; Song, You; Dobrynin, Danil; Pleshko, Nancy; Steinbeck, Marla J; Freeman, Theresa A

    2016-09-01

    The goal of this study was to investigate whether cold plasma generated by dielectric barrier discharge (DBD) modifies extracellular matrices (ECM) to influence chondrogenesis and endochondral ossification. Replacement of cartilage by bone during endochondral ossification is essential in fetal skeletal development, bone growth and fracture healing. Regulation of this process by the ECM occurs through matrix remodelling, involving a variety of cell attachment molecules and growth factors, which influence cell morphology and protein expression. The commercially available ECM, Matrigel, was treated with microsecond or nanosecond pulsed (μsp or nsp, respectively) DBD frequencies conditions at the equivalent frequencies (1 kHz) or power (~1 W). Recombinant human bone morphogenetic protein-2 was added and the mixture subcutaneously injected into mice to simulate ectopic endochondral ossification. Two weeks later, the masses were extracted and analysed by microcomputed tomography. A significant increase in bone formation was observed in Matrigel treated with μsp DBD compared with control, while a significant decrease in bone formation was observed for both nsp treatments. Histological and immunohistochemical analysis showed Matrigel treated with μsp plasma increased the number of invading cells, the amount of vascular endothelial growth factor and chondrogenesis while the opposite was true for Matrigel treated with nsp plasma. In support of the in vivo Matrigel study, 10 T1/2 cells cultured in vitro on μsp DBD-treated type I collagen showed increased expression of adhesion proteins and activation of survival pathways, which decreased with nsp plasma treatments. These results indicate DBD modification of ECM can influence cellular behaviours to accelerate or inhibit chondrogenesis and endochondral ossification. Copyright © 2016 John Wiley & Sons, Ltd.

  17. Bone

    NASA Astrophysics Data System (ADS)

    Helmberger, Thomas K.; Hoffmann, Ralf-Thorsten

    The typical clinical signs in bone tumours are pain, destruction and destabilization, immobilization, neurologic deficits, and finally functional impairment. Primary malignant bone tumours are a rare entity, accounting for about 0.2% of all malignancies. Also benign primary bone tumours are in total rare and mostly asymptomatic. The most common symptomatic benign bone tumour is osteoid osteoma with an incidence of 1:2000.

  18. Human osteoblast-like cells respond to mechanical strain with increased bone matrix protein production independent of hormonal regulation

    NASA Technical Reports Server (NTRS)

    Harter, L. V.; Hruska, K. A.; Duncan, R. L.

    1995-01-01

    Exposure of osteosarcoma cell lines to chronic intermittent strain increases the activity of mechano-sensitive cation (SA-cat) channels. The impact of mechano-transduction on osteoblast function has not been well studied. We analyzed the expression and production of bone matrix proteins in human osteoblast-like osteosarcoma cells, OHS-4, in response to chronic intermittent mechanical strain. The OHS-4 cells exhibit type I collagen production, 1,25-Dihydroxyvitamin D-inducible osteocalcin, and mineralization of the extracellular matrix. The matrix protein message level was determined from total RNA isolated from cells exposed to 1-4 days of chronic intermittent strain. Northern analysis for type I collagen indicated that strain increased collagen message after 48 h. Immunofluorescent labeling of type I collagen demonstrated that secretion was also enhanced with mechanical strain. Osteopontin message levels were increased several-fold by the application of mechanical load in the absence of vitamin D, and the two stimuli together produced an additive effect. Osteocalcin secretion was also increased with cyclic strain. Osteocalcin levels were not detectable in vitamin D-untreated control cells. However, after 4 days of induced load, significant levels of osteocalcin were observed in the medium. With vitamin D present, osteocalcin levels were 4 times higher in the medium of strained cells compared to nonstrained controls. We conclude that mechanical strain of osteoblast-like cells is sufficient to increase the transcription and secretion of matrix proteins via mechano-transduction without hormonal induction.

  19. Detailed Analysis of the Structural Changes of Bone Matrix During the Demineralization Process Using Raman Spectroscopy

    NASA Astrophysics Data System (ADS)

    Timchenko, E. V.; Zherdeva, L. A.; Timchenko, P. E.; Volova, L. T.; Ponomareva, U. V.

    The results of experimental research of human cortical bone tissue depending on demineralization time were represented using Raman spectroscopy. Depending on demineralization time the ratio of the mineral (РO43- and CO32-) and organic components (amide I) of bone tissue, as well as changes in the spectral regions responsible for the structural integrity of the collagen fibers in bone tissue (1200-1460 cm-1 and 2880-3000 cm-1) were investigated. The observed changes show a decrease in mineral components: thus, the value of Raman band intensity at 956 and 1069 cm-1 for 5 minutes demineralization is 68.5 and 77.3%, for 20 minutes - 55.1 and 61.1%, for 120 minutes - 32.8 and 37% from Raman intensity values of not demineralized tissue objects respectively.

  20. Histologic analysis of a novel extracellullar matrix membrane for guided bone regeneration: an experimental study in rabbits.

    PubMed

    Al-Asfour, Adel; Tengvall, Pentti; Andersson, Lars; Dahlin, Christer

    2013-01-01

    This experiment was conducted to study the histologic feasibility and biologic impact of Ti02 impregnation of an extracellullar matrix (ECM) membrane in guided bone regeneration. Eighteen adult New Zealand White rabbits were used. Bilateral bone defects were created in edentulous areas of the maxilla. The defects were filled with demineralized freeze-dried bone (DFDB). ECM was randomly pretreated with a suspension containing saline and 3 mg Ti02 granules. A regular ECM membrane served as a control on the contralateral side. Healing periods were 2, 4, and 8 weeks. Histologic and histomorphometric analyses were performed. The parameters assessed were (1) zone of inflammatory cells adjacent to ECM membrane, (2) presence of cellullar ingrowth into ECM, and (3) presence of Ti02 particles within the ECM barrier membrane. In general, no adverse reactions toward both groups of ECM membranes could be noted. The Ti02 particles remained within the ECM after 8 weeks of healing, making histologic detection of ECM easy. Histomorphometric analysis revealed low numbers of inflammatory cells adjacent to the ECM surface and adequate preservation and integration of the barrier. Contrasting Ti02 particles impregnated into the ECM membrane can be a very useful tool for the detection of similar biologic materials in in vivo models. PMID:23484168

  1. Changes in the distribution of extracellular matrix vesicles during healing of rat tibial bone (computerized morphometry and electron microscopy).

    PubMed

    Sela, J; Amir, D; Schwartz, Z; Weinberg, H

    1987-01-01

    A study of the distribution of extracellular matrix vesicles during the first 3 weeks of healing of adult rat tibial bone was performed by transmission electron microscopy in combination with computerized morphometry. Bone injury comprised removal of the marrow followed by regeneration of the tissue via a phase of primary mineralization. A total number of 39,498 vesicles were traced on electron micrographs and sorted according to their diameters, distance from the calcified front and types. The different vesicular types were defined as follows: (a) vesicles with electron lucent contents, i.e. "empty", (b) vesicles with amorphous electron opaque contents, i.e. "amorphic", (c) vesicles containing crystalline depositions, i.e. "crystal", and (d) vesicles containing crystalline structures with ruptured membranes i.e. "rupture". The vesicles were studied on the days 3, 6, 14 and 21 after bone injury. Most of the vesicles were concentrated between diameters of 0.07 and 0.17 micron. Most of the vesicles were found in a distance less than 3 microns from the calcified front. The sequence of changes of distances from the calcified front and of the vesicular diameters were recorded as follows: "rupture", "crystal", "amorphic" and "empty", the "rupture" type being the closet to the front and of the largest diameter in each day. The results of the present study confirm the accepted hypothesis on calcification via extracellular matrix vesicles. It is thought that the cell secretes "empty" vesicles that accumulate Ca and Pi forming amorphous calcium phosphate that is then converted to hydroxyapatite. This is followed by rupture of the vesicular membrane.(ABSTRACT TRUNCATED AT 250 WORDS)

  2. Demineralized Bone Matrix Add-On for Acceleration of Bone Healing in Atypical Subtrochanteric Femoral Fracture: A Consecutive Case-Control Study

    PubMed Central

    Kulachote, Noratep; Sirisreetreerux, Norachart; Chanplakorn, Pongsthorn; Fuangfa, Praman; Suphachatwong, Chanyut; Wajanavisit, Wiwat

    2016-01-01

    Background. Delayed union and nonunion are common complications in atypical femoral fractures (AFFs) despite having good fracture fixation. Demineralized bone matrix (DBM) is a successfully proven method for enhancing fracture healing of the long bone fracture and nonunion and should be used in AFFs. This study aimed to compare the outcome after subtrochanteric AFFs (ST-AFFs) fixation with and without DBM. Materials and Methods. A prospective study was conducted on 9 ST-AFFs patients using DBM (DBM group) during 2013-2014 and compared with a retrospective consecutive case series of ST-AFFs patients treated without DBM (2010–2012) (NDBM group, 9 patients). All patients were treated with the same standard guideline and followed up until fractures completely united. Postoperative outcomes were then compared. Results. DBM group showed a significant shorter healing time than NDBM group (28.1 ± 14.4 versus 57.9 ± 36.8 weeks, p = 0.04). Delayed union was found in 4 patients (44%) in DBM group compared with 7 patients (78%) in NDBM group (p > 0.05). No statistical difference of nonunion was demonstrated between both groups (DBM = 1 and NDBM = 2, p > 0.05). Neither postoperative infection nor severe local tissue reaction was found. Conclusions. DBM is safe and effective for accelerating the fracture healing in ST-AFFx and possibly reduces nonunion after fracture fixation. Trial registration number is TCTR20151021001. PMID:27022610

  3. Surgical Outcomes of Anterior Cervical Fusion Using Deminaralized Bone Matrix as Stand-Alone Graft Material: Single Arm, Pilot Study

    PubMed Central

    Chung, Ho-Jung; Ryu, Kyeong-Sik; Kim, Jin-Sung; Seong, Ji-Hoon

    2016-01-01

    Objective To investigate the safety and efficacy of demineralized bone matrix (DBM) as a bone graft substitute for anterior cervical discectomy and fusion (ACDF) surgery. Methods Twenty consecutive patients treated with ACDF using stand-alone polyestheretherketone (PEEK) cages (Zero-P) with DBM(CGDBM100) were prospectively evaluated with a minimum of 6 months of follow-up. Radiologic efficacy was evaluated with a 6-point scoring method for osseous fusion using plain radiograph and computed tomogrpahy scans. Clinical efficacy was evaluated using the visual analogue scale (VAS), Owestry disability index (ODI), and short-form health questionnaire-36. The safety of the bone graft substitute was assessed with vital sign monitoring and a survey measuring complications at each follow-up visit. Results There were significant improvements in VAS and ODI scores at a mean 6-month follow-up. Six months after surgery, solid fusion was achieved in all patients. Mean score on the 6-point scoring system was 5.1, and bony formation was found to score at least 4 points in all patients. There was no case with implant-related complications such as cage failure or migration, and no complications associated with the use of CGDBM100. Conclusion ACDF using CGDBM100 demonstrated good clinical and radiologic outcomes. The fusion rate was comparable with the published results of traditional ACDF. Therefore, the results of this study suggest that the use of a PEEK cage packed with DBM for ACDF is a safe and effective alternative to the gold standard of autologous iliac bone graft. PMID:27799989

  4. Effect of acemannan, an extracted polysaccharide from Aloe vera, on BMSCs proliferation, differentiation, extracellular matrix synthesis, mineralization, and bone formation in a tooth extraction model.

    PubMed

    Boonyagul, Sani; Banlunara, Wijit; Sangvanich, Polkit; Thunyakitpisal, Pasutha

    2014-07-01

    Aloe vera is a traditional wound healing medicine. We hypothesized acemannan, a polysaccharide extracted from Aloe vera gel, could affect bone formation. Primary rat bone marrow stromal cells (BMSCs) were treated with various concentrations of acemannan. New DNA synthesis, VEGF, BMP-2, alkaline phosphatase activity, bone sialoprotein, osteopontin expression, and mineralization were determined by [(3)H] thymidine incorporation assay, ELISA, biochemical assay, western blotting, and Alizarin Red staining, respectively. In an animal study, mandibular right incisors of male Sprague-Dawley rats were extracted and an acemannan treated sponge was placed in the socket. After 1, 2, and 4 weeks, the mandibles were dissected. Bone formation was evaluated by dual-energy X-ray absorptiometry and histopathological examination. The in vitro results revealed acemannan significantly increased BMSC proliferation, VEGF, BMP-2, alkaline phosphatase activity, bone sialoprotein and osteopontin expression, and mineralization. In-vivo results showed acemannan-treated groups had higher bone mineral density and faster bone healing compared with untreated controls. A substantial ingrowth of bone trabeculae was observed in acemannan-treated groups. These data suggest acemannan could function as a bioactive molecule inducing bone formation by stimulating BMSCs proliferation, differentiation into osteoblasts, and extracellular matrix synthesis. Acemannan could be a candidate natural biomaterial for bone regeneration.

  5. Effects of matrix metalloproteinase-1 on the myogenic differentiation of bone marrow-derived mesenchymal stem cells in vitro

    SciTech Connect

    Zheng, Zhenyang; Leng, Yan; Zhou, Chen; Ma, Zhenyu; Zhong, Zhigang; Shi, Xing-Ming; Zhang, Weixi

    2012-11-16

    Highlights: Black-Right-Pointing-Pointer MMP-1 is a member of the zinc-dependent endopeptidase family. Black-Right-Pointing-Pointer MMP-1 has no cytotoxic effects on BMSCs. Black-Right-Pointing-Pointer MMP-1 can promote the myogenic differentiation of BMSCs. Black-Right-Pointing-Pointer MyoD and desmin were chosen as myogenic markers in this study. -- Abstract: Matrix metalloproteinase-1 (MMP-1) is a member of the family of zinc-dependent endopeptidases that are capable of degrading extracellular matrix (ECM) and certain non-matrix proteins. It has been shown that MMP-1 can enhance muscle regeneration by improving the differentiation and migration of myoblasts. However, it is still not known whether MMP-1 can promote the myogenesis of bone marrow-derived mesenchymal stem cells (BMSCs). To address this question, we isolated BMSCs from C57BL/6J mice and investigated the effects of MMP-1 on their proliferation and myogenic differentiation. Our results showed that MMP-1 treatment, which had no cytotoxic effects on BMSCs, increased the mRNA and protein levels of MyoD and desmin in a dose-dependent manner, indicating that MMP-1 promoted myogenic differentiation of BMSCs in vitro. These results suggest that BMSCs may have a therapeutic potential for treating muscular disorders.

  6. Evaluation of bone matrix gelatin/fibrin glue and chitosan/gelatin composite scaffolds for cartilage tissue engineering.

    PubMed

    Wang, Z H; Zhang, J; Zhang, Q; Gao, Y; Yan, J; Zhao, X Y; Yang, Y Y; Kong, D M; Zhao, J; Shi, Y X; Li, X L

    2016-01-01

    This study was designed to evaluate bone matrix gelatin (BMG)/fibrin glue and chitosan/gelatin composite scaffolds for cartilage tissue engineering. Chondrocytes were isolated from costal cartilage of Sprague-Dawley rats and seeded on BMG/fibrin glue or chitosan/gelatin composite scaffolds. After different in vitro culture durations, the scaffolds were subjected to hematoxylin and eosin, Masson's trichrome, and toluidine blue staining, anti-collagen II and anti-aggrecan immunohistochemistry, and scanning electronic microscopy (SEM) analysis. After 2 weeks of culture, chondrocytes were distributed evenly on the surfaces of both scaffolds. Cell numbers and the presence of extracellular matrix components were markedly increased after 8 weeks of culture, and to a greater extent on the chitosan/gelatin scaffold. The BMG/fibrin glue scaffold showed signs of degradation after 8 weeks. Immunofluorescence analysis confirmed higher levels of collagen II and aggrecan using the chitosan/gelatin scaffold. SEM revealed that the majority of cells on the surface of the BMG/fibrin glue scaffold demonstrated a round morphology, while those in the chitosan/gelatin group had a spindle-like shape, with pseudopodia. Chitosan/gelatin scaffolds appear to be superior to BMG/ fibrin glue constructs in supporting chondrocyte attachment, proliferation, and biosynthesis of cartilaginous matrix components. PMID:27525846

  7. Matrix elasticity of void-forming hydrogels controls transplanted-stem-cell-mediated bone formation

    NASA Astrophysics Data System (ADS)

    Huebsch, Nathaniel; Lippens, Evi; Lee, Kangwon; Mehta, Manav; Koshy, Sandeep T.; Darnell, Max C.; Desai, Rajiv M.; Madl, Christopher M.; Xu, Maria; Zhao, Xuanhe; Chaudhuri, Ovijit; Verbeke, Catia; Kim, Woo Seob; Alim, Karen; Mammoto, Akiko; Ingber, Donald E.; Duda, Georg N.; Mooney, David J.

    2015-12-01

    The effectiveness of stem cell therapies has been hampered by cell death and limited control over fate. These problems can be partially circumvented by using macroporous biomaterials that improve the survival of transplanted stem cells and provide molecular cues to direct cell phenotype. Stem cell behaviour can also be controlled in vitro by manipulating the elasticity of both porous and non-porous materials, yet translation to therapeutic processes in vivo remains elusive. Here, by developing injectable, void-forming hydrogels that decouple pore formation from elasticity, we show that mesenchymal stem cell (MSC) osteogenesis in vitro, and cell deployment in vitro and in vivo, can be controlled by modifying, respectively, the hydrogel’s elastic modulus or its chemistry. When the hydrogels were used to transplant MSCs, the hydrogel’s elasticity regulated bone regeneration, with optimal bone formation at 60 kPa. Our findings show that biophysical cues can be harnessed to direct therapeutic stem cell behaviours in situ.

  8. Evaluation of radiotherapy and chemotherapy effects in bone matrix using X-ray microfluorescence

    NASA Astrophysics Data System (ADS)

    Andrade, C. B. V.; Salata, C.; Silva, C. M.; Ferreira-Machado, S. C.; Braz, D.; Almeida, A. P.; Nogueira, L. P.; Barroso, R. C.; deAlmeida, C. E.; Mantuano, A.; Mota, C. L.; Pickler, A.

    2014-02-01

    Premenopausal women undergoing adjuvant chemotherapy and/or radiotherapy for Breast Cancer (BC) treatment have significant bone loss. This high bone mineral density loss can lead to an increased risk of fractures. In this study, there were evaluated parameters involved in osteoporosis when rats were subjected to a chemotherapy regimen (TC) and/or irradiation (IR). Female Wistar rats were divided into 3 groups: control (G1), TC+IR (G2) and IR (G3). The animals were euthanized after 5 months at the end of treatment and their femurs were excised and dissected. Sections of 10 μm thick were used for μXRF analysis at the National Laboratory of Synchrotron Light. The uteri of these rats were collected and weighed. The obtained results showed that animals from G2 had a significant reduction (p<0.05) of uterine mass when compared to control. The qualitative analysis performed by μXRF showed that animals from G2 had iron in bone composition of the femurs. This same result was notobserved in animals from G1 and G3 groups. These results suggest that early menopause occurs and osteoporosis begins, probably because of the absence, or reduced, production of estrogen. The presence of iron in the G2 samples in indicates the process of osteoporosis, because according to literature, this ion is competitive with calcium ions.

  9. Transcript-activated collagen matrix as sustained mRNA delivery system for bone regeneration.

    PubMed

    Badieyan, Zohreh Sadat; Berezhanskyy, Taras; Utzinger, Maximilian; Aneja, Manish Kumar; Emrich, Daniela; Erben, Reinhold; Schüler, Christiane; Altpeter, Philipp; Ferizi, Mehrije; Hasenpusch, Günther; Rudolph, Carsten; Plank, Christian

    2016-10-10

    Transcript therapies using chemically modified messenger RNAs (cmRNAs) are emerging as safe and promising alternatives for gene and recombinant protein therapies. However, their applications have been limited due to transient translation and relatively low stability of cmRNAs compared to DNA. Here we show that vacuum-dried cmRNA-loaded collagen sponges, termed transcript activated matrices (TAMs), can serve as depots for sustained delivery of cmRNA. TAMs provide steady state protein production for up to six days, and substantial residual expression until 11days post transfection. Another advantage of this technology was nearly 100% transfection efficiency as well as low toxicity in vitro. TAMs were stable for at least 6months at room temperature. Human BMP-2-encoding TAMs induced osteogenic differentiation of MC3T3-E1 cells in vitro and bone regeneration in a non-critical rat femoral bone defect model in vivo. In summary, TAMs are a promising tool for bone regeneration and potentially also for other applications in regenerative medicine and tissue engineering. PMID:27586186

  10. Pigment epithelium derived factor suppresses expression of Sost/Sclerostin by osteocytes: implication for its role in bone matrix mineralization.

    PubMed

    Li, Feng; Song, Na; Tombran-Tink, Joyce; Niyibizi, Christopher

    2015-06-01

    Mutations in Serpinf1 gene which encodes pigment epithelium derived factor (PEDF) lead to osteogenesis imperfecta type VI whose hallmark is defective mineralization. Mechanisms by which PEDF regulates matrix mineralization remain unknown. We examined effect of exogenous PEDF on expression of osteoblastic and osteocytic related genes and proteins in mineralizing osteoblast culture. Mineralizing human osteoblasts supplemented with exogenous PEDF for 14 days deposited 47% more mineral than cells cultured without PEDF. Analysis of selected gene expression by cells in mineralizing cultures supplemented with exogenous PEDF showed reduction in expression of Sclerostin (Sost) by 70%, matrix extracellular phosphoglycoprotein (MEPE) by 75% and dentin matrix protein (DMP-1) by 20% at day 14 of culture. Phosphate-regulating gene with homologies to endopeptidases on the X chromosome (PHEX) expression was not affected. Western blotting and immunoprecipitation showed that sclerostin and MEPE synthesis by osteocytes were reduced by 50% and 60% respectively in mineralizing osteoblasts containing exogenous PEDF. Primary osteocytes exposed to PEDF also reduced synthesis of Sost/sclerostin by 50% within 24 h. For osteoblastic genes, Bone sialoprotein (BSP) was expressed at 75% higher by day 7 in cultures containing exogenous PEDF while Col1A1 expression remained high at all-time points. Total beta-catenin was increased in mineralizing osteoblastic cells suggesting increased Wnt activity. Taken together, the data indicate that PEDF suppressed expression of factors that inhibit mineralization while enhancing those that promote mineralization. The findings also suggest that PEDF may regulate Sost expression by osteocytes leading to enhanced osteoblastic differentiation and increased matrix mineralization.

  11. Human Acellular Dermis versus Submuscular Tissue Expander Breast Reconstruction: A Multivariate Analysis of Short-Term Complications

    PubMed Central

    Davila, Armando A.; Seth, Akhil K.; Wang, Edward; Hanwright, Philip; Bilimoria, Karl; Fine, Neil

    2013-01-01

    Background Acellular dermal matrix (ADM) allografts and their putative benefits have been increasingly described in prosthesis based breast reconstruction. There have been a myriad of analyses outlining ADM complication profiles, but few large-scale, multi-institutional studies exploring these outcomes. In this study, complication rates of acellular dermis-assisted tissue expander breast reconstruction were compared with traditional submuscular methods by evaluation of the American College of Surgeon's National Surgical Quality Improvement Program (NSQIP) registry. Methods Patients who underwent immediate tissue expander breast reconstruction from 2006-2010 were identified using surgical procedure codes. Two hundred forty tracked variables from over 250 participating sites were extracted for patients undergoing acellular dermis-assisted versus submuscular tissue expander reconstruction. Thirty-day postoperative outcomes and captured risk factors for complications were compared between the two groups. Results A total of 9,159 patients underwent tissue expander breast reconstruction; 1,717 using acellular dermis and 7,442 with submuscular expander placement. Total complications and reconstruction related complications were similar in both cohorts (5.5% vs. 5.3%, P=0.68 and 4.7% vs. 4.3%, P=0.39, respectively). Multivariate logistic regression revealed body mass index and smoking as independent risk factors for reconstructive complications in both cohorts (P<0.01). Conclusions The NSQIP database provides large-scale, multi-institutional, independent outcomes for acellular dermis and submuscular breast reconstruction. Both thirty-day complication profiles and risk factors for post operative morbidity are similar between these two reconstructive approaches. PMID:23362476

  12. The role of novel and known extracellular matrix and adhesion molecules in the homeostatic and regenerative bone marrow microenvironment

    PubMed Central

    Klamer, Sofieke; Voermans, Carlijn

    2014-01-01

    Maintenance of haematopoietic stem cells and differentiation of committed progenitors occurs in highly specialized niches. The interactions of haematopoietic stem and progenitor cells (HSPCs) with cells, growth factors and extracellular matrix (ECM) components of the bone marrow (BM) microenvironment control homeostasis of HSPCs. We only start to understand the complexity of the haematopoietic niche(s) that comprises endosteal, arterial, sinusoidal, mesenchymal and neuronal components. These distinct niches produce a broad range of soluble factors and adhesion molecules that modulate HSPC fate during normal hematopoiesis and BM regeneration. Adhesive interactions between HSPCs and the microenvironment will influence their localization and differentiation potential. In this review we highlight the current understanding of the functional role of ECM- and adhesion (regulating) molecules in the haematopoietic niche during homeostatic and regenerative hematopoiesis. This knowledge may lead to the improvement of current cellular therapies and more efficient development of future cellular products. PMID:25482635

  13. Matrix Rigidity Regulates the Transition of Tumor Cells to a Bone-Destructive Phenotype through Integrin β3 and TGF-β Receptor Type II

    PubMed Central

    Ruppender, Nazanin S.; Guo, Ruijing; Dadwal, Ushashi C.; Cannonier, Shellese; Basu, Sandip; Guelcher, Scott A.; Sterling, Julie A.

    2015-01-01

    Cancer patients frequently develop skeletal metastases that significantly impact quality of life. Since bone metastases remain incurable, a clearer understanding of molecular mechanisms regulating skeletal metastases is required to develop new therapeutics that block establishment of tumors in bone. While many studies have suggested that the microenvironment contributes to bone metastases, the factors mediating tumors to progress from a quiescent to a bone-destructive state remain unclear. In this study, we hypothesized that the “soil” of the bone microenvironment, specifically the rigid mineralized extracellular matrix, stimulates the transition of the tumor cells to a bone-destructive phenotype. To test this hypothesis, we synthesized 2D polyurethane (PUR) films with elastic moduli ranging from the basement membrane (70 MPa) to cortical bone (3800 MPa) and measured expression of genes associated with mechanotransduction and bone metastases. We found that expression of Integrin β3 (Iβ3), as well as tumor-produced factors associated with bone destruction (Gli2 and parathyroid hormone related protein (PTHrP)), significantly increased with matrix rigidity, and that blocking Iβ3 reduced Gli2 and PTHrP expression. To identify the mechanism by which Iβ3 regulates Gli2 and PTHrP (both are also known to be regulated by TGF-β), we performed Förster resonance energy transfer (FRET) and immunoprecipitation, which indicated that Iβ3 co-localized with TGF-β Receptor Type II (TGF-β RII) on rigid but not compliant films. Finally, transplantation of tumor cells expressing Iβ3 shRNA into the tibiae of athymic nude mice significantly reduced PTHrP and Gli2 expression, as well as bone destruction, suggesting a crucial role for tumor-produced Iβ3 in disease progression. This study demonstrates that the rigid mineralized bone matrix can alter gene expression and bone destruction in an Iβ3/TGF-β-dependent manner, and suggests that Iβ3 inhibitors are a potential

  14. Matrix rigidity regulates the transition of tumor cells to a bone-destructive phenotype through integrin β3 and TGF-β receptor type II.

    PubMed

    Page, Jonathan M; Merkel, Alyssa R; Ruppender, Nazanin S; Guo, Ruijing; Dadwal, Ushashi C; Cannonier, Shellese A; Basu, Sandip; Guelcher, Scott A; Sterling, Julie A

    2015-09-01

    Cancer patients frequently develop skeletal metastases that significantly impact quality of life. Since bone metastases remain incurable, a clearer understanding of molecular mechanisms regulating skeletal metastases is required to develop new therapeutics that block establishment of tumors in bone. While many studies have suggested that the microenvironment contributes to bone metastases, the factors mediating tumors to progress from a quiescent to a bone-destructive state remain unclear. In this study, we hypothesized that the "soil" of the bone microenvironment, specifically the rigid mineralized extracellular matrix, stimulates the transition of the tumor cells to a bone-destructive phenotype. To test this hypothesis, we synthesized 2D polyurethane (PUR) films with elastic moduli ranging from the basement membrane (70 MPa) to cortical bone (3800 MPa) and measured expression of genes associated with mechanotransduction and bone metastases. We found that expression of Integrin β3 (Iβ3), as well as tumor-produced factors associated with bone destruction (Gli2 and parathyroid hormone related protein (PTHrP)), significantly increased with matrix rigidity, and that blocking Iβ3 reduced Gli2 and PTHrP expression. To identify the mechanism by which Iβ3 regulates Gli2 and PTHrP (both are also known to be regulated by TGF-β), we performed Förster resonance energy transfer (FRET) and immunoprecipitation, which indicated that Iβ3 co-localized with TGF-β Receptor Type II (TGF-β RII) on rigid but not compliant films. Finally, transplantation of tumor cells expressing Iβ3 shRNA into the tibiae of athymic nude mice significantly reduced PTHrP and Gli2 expression, as well as bone destruction, suggesting a crucial role for tumor-produced Iβ3 in disease progression. This study demonstrates that the rigid mineralized bone matrix can alter gene expression and bone destruction in an Iβ3/TGF-β-dependent manner, and suggests that Iβ3 inhibitors are a potential

  15. Mimicking bone extracellular matrix: integrin-binding peptidomimetics enhance osteoblast-like cells adhesion, proliferation, and differentiation on titanium.

    PubMed

    Fraioli, Roberta; Rechenmacher, Florian; Neubauer, Stefanie; Manero, José M; Gil, Javier; Kessler, Horst; Mas-Moruno, Carlos

    2015-04-01

    Interaction between the surface of implants and biological tissues is a key aspect of biomaterials research. Apart from fulfilling the non-toxicity and structural requirements, synthetic materials are asked to direct cell response, offering engineered cues that provide specific instructions to cells. This work explores the functionalization of titanium with integrin-binding peptidomimetics as a novel and powerful strategy to improve the adhesion, proliferation and differentiation of osteoblast-like cells to implant materials. Such biomimetic strategy aims at targeting integrins αvβ3 and α5β1, which are highly expressed on osteoblasts and are essential for many fundamental functions in bone tissue development. The successful grafting of the bioactive molecules on titanium is proven by contact angle measurements, X-ray photoelectron spectroscopy and fluorescent labeling. Early attachment and spreading of cells are statistically enhanced by both peptidomimetics compared to unmodified titanium, reaching values of cell adhesion comparable to those obtained with full-length extracellular matrix proteins. Moreover, an increase in alkaline phosphatase activity, and statistically higher cell proliferation and mineralization are observed on surfaces coated with the peptidomimetics. This study shows an unprecedented biological activity for low-molecular-weight ligands on titanium, and gives striking evidence of the potential of these molecules to foster bone regeneration on implant materials. PMID:25637448

  16. Mechanobiology of bone marrow stem cells: from myosin-II forces to compliance of matrix and nucleus

    PubMed Central

    Shin, Jae-Won; Swift, Joe; Ivanovska, Irena; Spinler, Kyle R.; Buxboim, Amnon; Discher, Dennis E.

    2014-01-01

    Adult stem cells and progenitors are of great interest for their clinical application as well as their potential to reveal deep sensitivities to microenvironmental factors. The bone marrow is a niche for at least two types of stem cells, and the prototype is the hematopoietic stem cell/progenitors (HSC/Ps), which have saved many thousands of patients for several decades now. In bone marrow, HSC/Ps interact functionally with marrow stromal cells that are often referred to as mesenchymal stem cells (MSCs) or derivatives thereof. Myosin and matrix elasticity greatly effect MSC function, and these mechanobiological factors are now being explored with HSC/Ps both in vitro and in vivo. Also emerging is a role for the nucleus as a mechanically sensitive organelle that is semi-permeable to transcription factors which are modified for nuclear entry by cytoplasmic mechanobiological pathways. Since therapies envisioned with induced pluripotent stem cells and embryonic stem cells generally involve in vitro commitment to an adult stem cell or progenitor, a very deep understanding of stem cell mechanobiology is essential to progress with these multi-potent cells. PMID:23790394

  17. Mimicking bone extracellular matrix: integrin-binding peptidomimetics enhance osteoblast-like cells adhesion, proliferation, and differentiation on titanium.

    PubMed

    Fraioli, Roberta; Rechenmacher, Florian; Neubauer, Stefanie; Manero, José M; Gil, Javier; Kessler, Horst; Mas-Moruno, Carlos

    2015-04-01

    Interaction between the surface of implants and biological tissues is a key aspect of biomaterials research. Apart from fulfilling the non-toxicity and structural requirements, synthetic materials are asked to direct cell response, offering engineered cues that provide specific instructions to cells. This work explores the functionalization of titanium with integrin-binding peptidomimetics as a novel and powerful strategy to improve the adhesion, proliferation and differentiation of osteoblast-like cells to implant materials. Such biomimetic strategy aims at targeting integrins αvβ3 and α5β1, which are highly expressed on osteoblasts and are essential for many fundamental functions in bone tissue development. The successful grafting of the bioactive molecules on titanium is proven by contact angle measurements, X-ray photoelectron spectroscopy and fluorescent labeling. Early attachment and spreading of cells are statistically enhanced by both peptidomimetics compared to unmodified titanium, reaching values of cell adhesion comparable to those obtained with full-length extracellular matrix proteins. Moreover, an increase in alkaline phosphatase activity, and statistically higher cell proliferation and mineralization are observed on surfaces coated with the peptidomimetics. This study shows an unprecedented biological activity for low-molecular-weight ligands on titanium, and gives striking evidence of the potential of these molecules to foster bone regeneration on implant materials.

  18. Liver-derived matrix metalloproteinase-9 (gelatinase B) recruits progenitor cells from bone marrow into the blood circulation.

    PubMed

    Watanabe, Yoshifumi; Haruyama, Takahiro; Akaike, Toshihiro

    2003-04-01

    Matrix metalloproteinases (MMPs) are involved in invasive cell behavior, embryonic development and organ remodeling. In this report, we investigated the role of liver-derived MMP-9 in the in vivo system at liver injury. Liver injury induced MMP-9 expression in the liver 3 to 12 h after intravenous administration of anti-Fas antibody, followed by the expression of the activity and the protein detected by zymography and Western blotting, respectively, in the blood circulation. Interestingly, the MMP-9 expression was accompanied by the recruitment of hematopoietic progenitor cells from bone marrow into the circulation. The recruitment was blocked by a specific MMP-9 inhibitor, R94138, which did not affect the Fas-mediated liver injury or induced expression of MMP-9. Compulsive expression of mutant active MMP-9 in the liver also recruited the progenitor cells into the circulation. In contrast, partial hepatectomy, which treatment does not directly injure hepatocytes, did not recruit progenitor cells despite the increased expression of MMP-9 in the circulation. These results suggest that liver-derived MMP-9 induced by liver injury plays an essential role in the recruitment of hematopoietic progenitor cells from bone marrow into the blood circulation.

  19. Treatment of intrabony defects with anorganic bone matrix/p-15 or guided tissue regeneration in patients with aggressive periodontitis.

    PubMed

    Queiroz, Adriana C; Nóbrega, Priscila Brasil da; Oliveira, Fabíola S; Novaes, Arthur B; Taba, Mário; Palioto, Daniela B; Grisi, Márcio F M; Souza, Sergio L S

    2013-01-01

    Intrabony periodontal defects present a particular treatment problem, especially in patients with generalized aggressive periodontitis (G-AgP). Regenerative procedures have been indicated for this clinical situation. The aim of this study was to compare treatment outcomes of intrabony periodontal defects with either anorganic bone matrix/cell binding peptide (ABM/P-15) or guided tissue regeneration (GTR) in patients with G-AgP. Fifteen patients, with two intrabony defects ≥3 mm deep, were selected. Patients were randomly allocated to be treated with ABM/P-15 or GTR. At baseline and at 3 and 6 months after surgery, clinical and radiographic parameters and IL-1β and IL-6 gingival fluid concentrations were recorded. There was a significant probing pocket depth reduction (p<0.001) for both groups (2.27 ± 0.96 mm for ABM/P-15 group and 2.57 ± 1.06 mm for GTR group). Clinical attachment level gain (1.87 ± 0.94 mm for ABM/P-15 group and 2.09 ± 0.88 mm for GTR group) was also observed. There were no statistically significant differences in clinical parameters between the groups. The radiographic bone fill was more expressive in ABM/P-15 group (2.49 mm) than in GTR group (0.73 mm). In subtraction radiographs, the areas representing gain in density were 93.16% of the baseline defect for ABM/P-15 group versus 62.03% in GRT group. There were no statistically significant differences in inter-group and intra-group comparisons with regards to IL-1β and IL-6 quantification. Treatment of intrabony periodontal defects in patients with G-AgP with ABM/P-15 and GTR improved significantly the clinical outcomes. The use of ABM/P-15 promoted a better radiographic bone fill. PMID:23969907

  20. Effects of ethanol on gene expression in rat bone: transient dose-dependent changes in mRNA levels for matrix proteins, skeletal growth factors, and cytokines are followed by reductions in bone formation.

    PubMed

    Turner, R T; Wronski, T J; Zhang, M; Kidder, L S; Bloomfield, S A; Sibonga, J D

    1998-10-01

    Several studies were performed in female rats to determine dose and time course changes in mRNA levels for matrix proteins in bone after a single administration of ethanol. As expected, dose-dependent transient increases in blood ethanol were measured. Additionally, there was mild hypocalcemia with no change in immunoreactive parathyroid hormone. Coordinated dose-dependent increases in mRNA for type 1 collagen, osteonectin, and osteocalcin were noted in the proximal tibial metaphysis 6 hr after ethanol was given, with the peak values occurring at a dose of 1.2 g/kg (0.4 ml). Similar increases in mRNA levels for matrix proteins were noted in lumbar vertebrae after ethanol treatment. The changes were specific for bone; ethanol had no effect on mRNA levels for matrix proteins in the uterus or liver, although the mRNA concentrations tended to be reduced in uterus. Message levels for several cytokines implicated in the regulation of bone turnover were also assayed; mRNA levels for transforming growth factor-beta1, transforming growth factor-beta2, interferon-gamma, and interleukin-6 were unchanged at doses ranging from 0.14 to 1.7 g/kg. At the highest dose of ethanol, the mRNA level for tumor necrosis factor-alpha was elevated while the level for insulin-like growth factor-1 was reduced. The time course effects of ethanol (0.4 ml dose) were determined in a separate experiment. Ethanol resulted in a transient increase in mRNA levels for the three bone matrix proteins assayed. However, matrix protein synthesis, as determined by incorporation of 3H-proline into the proximal tibial metaphysis, was not changed after 6 hr. The changes in mRNA levels for the matrix proteins were preceded by brief, transient decreases in mRNA levels for interleukin-1beta, interferon-gamma, and migration inhibitory factor, and followed by a more prolonged decrease in the mRNA level for insulin-like growth factor-1. A subsequent study was performed to determine the effects of repetitive daily

  1. Matrix Elasticity of Void-Forming Hydrogels Controls Transplanted Stem Cell-Mediated Bone Formation

    PubMed Central

    Huebsch, Nathaniel; Lippens, Evi; Lee, Kangwon; Mehta, Manav; Koshy, Sandeep T; Darnell, Max C; Desai, Rajiv; Madl, Christopher M.; Xu, Maria; Zhao, Xuanhe; Chaudhuri, Ovijit; Verbeke, Catia; Kim, Woo Seob; Alim, Karen; Mammoto, Akiko; Ingber, Donald E.; Duda, Georg N; Mooney, David J.

    2015-01-01

    The effectiveness of stem-cell therapies has been hampered by cell death and limited control over fate1. These problems can be partially circumvented by using macroporous biomaterials that improve the survival of transplanted stem cells and provide molecular cues to direct cell phenotype2–4. Stem cell behavior can also be controlled in vitro by manipulating the elasticity of both porous and non-porous materials5–7, yet translation to therapeutic processes in vivo remains elusive. Here, by developing injectable, void-forming hydrogels that decouple pore formation from elasticity, we show that mesenchymal stem cell (MSC) osteogenesis in vitro, and cell deployment in vitro and in vivo, can be controlled by modifying, respectively, the hydrogel's elastic modulus or its chemistry. When the hydrogels were used to transplant MSCs, the hydrogel's elasticity regulated bone regeneration, with optimal bone formation at 60 kPa. Our findings show that biophysical cues can be harnessed to direct therapeutic stem-cell behaviors in situ. PMID:26366848

  2. The distribution of extracellular matrix vesicles in healing of rat tibial bone three days after intramedullary injury.

    PubMed

    Amir, D; Schwartz, Z; Weinberg, H; Sela, J

    1988-01-01

    The distribution of extracellular matrix vesicles on the third day of bone healing was studied by morphometric analysis of transmission electron micrographs. Detection and grouping of the vesicles was performed according to type, diameter, and distance from the calcified front. The different types were selected as follows: vesicles with electron-lucent contents ("empty"), vesicles with amorphous electron-opaque contents ("amorphic"), vesicles containing crystalline depositions ("crystal"), and vesicles containing crystalline structures with ruptured membranes ("rupture"). The majority of vesicles were between 0.07 micron and 0.12 micron in diameter and were located at less than 3 micron from the calcified front. The distribution of the "empty", "amorphic", "crystal", and "rupture" vesicles was 23.2%, 74%, 2.5%, and 0.3% respectively. Their sequence of arrangement according to diameter was as follows: "empty", "amorphic", "crystal", and "rupture", the empty vesicles constituting the smallest and the "rupture" the largest type. Distances from the calcified front were similar for the "empty", "amorphic", and "crystal" vesicles, while the "rupture" type was located nearest to the front. The present observations support the widely acknowledged hypothesis on the role of extracellular matrix vesicles in mineralization. It is thought that the secretion of "empty" vesicles from the cell is followed by intravascular accumulation of amorphous Ca and Pi to form a hydroxyapatite crystal that, in turn, ruptures the vesicle's membrane.(ABSTRACT TRUNCATED AT 250 WORDS)

  3. Matrix formation is enhanced in co-cultures of human meniscus cells with bone marrow stromal cells.

    PubMed

    Matthies, Norah-Faye; Mulet-Sierra, Aillette; Jomha, Nadr M; Adesida, Adetola B

    2013-12-01

    The ultimate aim of this study was to assess the feasibility of using human bone marrow stromal cells (BMSCs) to supplement meniscus cells for meniscus tissue engineering and regeneration. Human menisci were harvested from three patients undergoing total knee replacements. Meniscus cells were released from the menisci after collagenase treatment. BMSCs were harvested from the iliac crest of three patients and were expanded in culture until passage 2. Primary meniscus cells and BMSCs were co-cultured in vitro in three-dimensional (3D) pellet culture at three different cell-cell ratios for 3 weeks under normal (21% O2 ) or low (3% O2 ) oxygen tension in the presence of serum-free chondrogenic medium. Pure BMSCs and pure meniscus cell pellets served as control groups. The tissue generated was assessed biochemically, histochemically and by quantitative RT-PCR. Co-cultures of primary meniscus cells and BMSCs resulted in tissue with increased (1.3-1.7-fold) deposition of proteoglycan (GAG) extracellular matrix (ECM) relative to tissues derived from BMSCs or meniscus cells alone under 21% O2 . GAG matrix formation was also enhanced (1.3-1.6-fold) under 3% O2 culture conditions. Alcian blue staining of generated tissue confirmed increased deposition of GAG-rich matrix. mRNA expression of type I collagen (COL1A2), type II collagen (COL2A1) and aggrecan were upregulated in co-cultured pellets. However, SOX9 and HIF-1α mRNA expression were not significantly modulated by co-culture. Co-culture of primary meniscus cells with BMSCs resulted in increased ECM formation. Co-delivery of meniscus cells and BMSCs can, in principle, be used in tissue engineering and regenerative medicine strategies to repair meniscus defects.

  4. Creation and implantation of acellular rat renal ECM-based scaffolds

    PubMed Central

    Peloso, Andrea; Ferrario, Jacopo; Maiga, Benedetta; Benzoni, Ilaria; Bianco, Carolina; Citro, Antonio; Currao, Manuela; Malara, Alessandro; Gaspari, Annalisa; Balduini, Alessandra; Abelli, Massimo; Piemonti, Lorenzo; Dionigi, Paolo; Orlando, Giuseppe; Maestri, Marcello

    2015-01-01

    Abstract Kidney transplantation is the only potentially curative treatment for patient facing end-stage renal disease, and it is now routinely used. Its use is mainly limited by the supply of transplantable donor organs, which far exceeds the demand. Regenerative medicine and tissue engineering offer promising means for overcoming this shortage. In the present study, we developed and validated a protocol for producing acellular rat renal scaffolds. Left kidneys were removed from 26 male Lewis rats (weights: 250–350 g) and decellularized by means of aortic anterograde perfusion with ionic and anionic detergents (Triton X-100 1% and SDS 1%, respectively). 19 scaffolds thus obtained (and contralateral native kidneys as controls) were deeply characterized in order to evaluate the decellularization quality, the preservation of extracellular matrix components and resultant micro-angioarchitecture structure. The other 7 were transplanted into 7 recipient rats that had undergone unilateral nephrectomy. Recipients were sacrificed on post-transplantation day 7 and the scaffolds subjected to histologic studies. The dual-detergent protocol showed, with only 5 h of perfusion per organ, to obtain thoroughly decellularized renal scaffolds consisting almost exclusively of extracellular matrix. Finally the macro- and the microarchitecture of the renal parenchyma were well preserved, and the grafts were implanted with ease. Seven days after transplant, the scaffolds were morphologically intact although all vascular structures were obstructed with thrombi. Production and implantation of acellular rat renal scaffolds is a suitable platform for further studies on regenerative medicine and tissue engineering. PMID:26186418

  5. Creation and implantation of acellular rat renal ECM-based scaffolds.

    PubMed

    Peloso, Andrea; Ferrario, Jacopo; Maiga, Benedetta; Benzoni, Ilaria; Bianco, Carolina; Citro, Antonio; Currao, Manuela; Malara, Alessandro; Gaspari, Annalisa; Balduini, Alessandra; Abelli, Massimo; Piemonti, Lorenzo; Dionigi, Paolo; Orlando, Giuseppe; Maestri, Marcello

    2015-01-01

    Kidney transplantation is the only potentially curative treatment for patient facing end-stage renal disease, and it is now routinely used. Its use is mainly limited by the supply of transplantable donor organs, which far exceeds the demand. Regenerative medicine and tissue engineering offer promising means for overcoming this shortage. In the present study, we developed and validated a protocol for producing acellular rat renal scaffolds. Left kidneys were removed from 26 male Lewis rats (weights: 250-350 g) and decellularized by means of aortic anterograde perfusion with ionic and anionic detergents (Triton X-100 1% and SDS 1%, respectively). 19 scaffolds thus obtained (and contralateral native kidneys as controls) were deeply characterized in order to evaluate the decellularization quality, the preservation of extracellular matrix components and resultant micro-angioarchitecture structure. The other 7 were transplanted into 7 recipient rats that had undergone unilateral nephrectomy. Recipients were sacrificed on post-transplantation day 7 and the scaffolds subjected to histologic studies. The dual-detergent protocol showed, with only 5 h of perfusion per organ, to obtain thoroughly decellularized renal scaffolds consisting almost exclusively of extracellular matrix. Finally the macro- and the microarchitecture of the renal parenchyma were well preserved, and the grafts were implanted with ease. Seven days after transplant, the scaffolds were morphologically intact although all vascular structures were obstructed with thrombi. Production and implantation of acellular rat renal scaffolds is a suitable platform for further studies on regenerative medicine and tissue engineering. PMID:26186418

  6. The NH2-terminal and COOH-terminal fragments of dentin matrix protein 1 (DMP1) localize differently in the compartments of dentin and growth plate of bone.

    PubMed

    Maciejewska, Izabela; Cowan, Cameron; Svoboda, Kathy; Butler, William T; D'Souza, Rena; Qin, Chunlin

    2009-02-01

    Multiple studies have shown that dentin matrix protein 1 (DMP1) is essential for bone and dentin mineralization. After post-translational proteolytic cleavage, DMP1 exists within the extracellular matrix of bone and dentin as an NH2-terminal fragment, a COOH-terminal fragment, and the proteoglycan form of the NH2-terminal fragment (DMP1-PG). To begin to assess the biological function of each fragment, we evaluated the distribution of both fragments in the rat tooth and bone using antibodies specific to the NH2-terminal and COOH-terminal regions of DMP1 and confocal microscopy. In rat first molar organs, the NH2-terminal fragment localized to predentin, whereas the COOH-terminal fragment was mainly restricted to mineralized dentin. In the growth plate of bone, the NH2-terminal fragment appeared in the proliferation and hypertrophic zones, whereas the COOH-terminal fragment occupied the ossification zone. Forster resonance energy transfer analysis showed colocalization of both fragments of DMP1 in odontoblasts and predentin, as well as hypertrophic chondrocytes within the growth plates of bone. The biochemical analysis of bovine teeth showed that predentin is rich in DMP1-PG, whereas mineralized dentin primarily contains the COOH-terminal fragment. We conclude that the differential patterns of expression of NH2-terminal and COOH-terminal fragments of DMP1 reflect their potentially distinct roles in the biomineralization of dentin and bone matrices.

  7. Altered Composition of Bone as Triggered by Irradiation Facilitates the Rapid Erosion of the Matrix by Both Cellular and Physicochemical Processes

    PubMed Central

    Green, Danielle E.; Adler, Benjamin J.; Chan, Meilin Ete; Lennon, James J.; Acerbo, Alvin S.; Miller, Lisa M.; Rubin, Clinton T.

    2013-01-01

    Radiation rapidly undermines trabecular architecture, a destructive process which proceeds despite a devastated cell population. In addition to the ‘biologically orchestrated’ resorption of the matrix by osteoclasts, physicochemical processes enabled by a damaged matrix may contribute to the rapid erosion of bone quality. 8w male C57BL/6 mice exposed to 5 Gy of Cs137 γ-irradiation were compared to age-matched control at 2d, 10d, or 8w following exposure. By 10d, irradiation had led to significant loss of trabecular bone volume fraction. Assessed by reflection-based Fourier transform infrared imaging (FTIRI), chemical composition of the irradiated matrix indicated that mineralization had diminished at 2d by −4.3±4.8%, and at 10d by −5.8±3.2%. These data suggest that irradiation facilitates the dissolution of the matrix through a change in the material itself, a conclusion supported by a 13.7±4.5% increase in the elastic modulus as measured by nanoindentation. The decline in viable cells within the marrow of irradiated mice at 2d implies that the immediate collapse of bone quality and inherent increased risk of fracture is not solely a result of an overly-active biologic process, but one fostered by alterations in the material matrix that predisposes the material to erosion. PMID:23741433

  8. The extent and distribution of cell death and matrix damage in impacted chondral explants varies with the presence of underlying bone.

    PubMed

    Krueger, J A; Thisse, P; Ewers, B J; Dvoracek-Driksna, D; Orth, M W; Haut, R C

    2003-02-01

    Excessive mechanical loading can lead to matrix damage and chondrocyte death in articular cartilage. Previous studies on chondral and osteochondral explants have not clearly distinguished to what extent the degree and the distribution of cell death are dependent on the presence of an underlying layer of bone. The current study hypothesized that the presence of underlying bone would decrease the amount of matrix damage and cell death. Chondral and osteochondral explants were loaded to 30 MPa at a high rate of loading (approximately 600 MPa/s) or at a low rate of loading (30 MPa/s). After 24 hours in culture, matrix damage was assessed by the total length and average depth of surface fissures. The explants were also sectioned and stained for cell viability in the various layers of the cartilage. More matrix damage was documented in chondral than osteochondral explants for each rate of loading experiment. The total amount of cell death was also less in osteochondral explants than chondral explants. The presence of underlying bone significantly reduced the extent of cell death in all zones in low rate of loading tests. The percentage of cell death was also reduced in the intermediate zone and deep zones of the explant by the presence of the underlying bone for a high rate of loading. This study indicated that the presence of underlying bone significantly limited the degree of matrix damage and cell death, and also affected the distribution of dead cells through the explant thickness. These data may have relevance to the applicability of experimental data from chondral explants to the in situ condition.

  9. Dual luciferase labelling for non-invasive bioluminescence imaging of mesenchymal stromal cell chondrogenic differentiation in demineralized bone matrix scaffolds.

    PubMed

    Vilalta, Marta; Jorgensen, Christian; Dégano, Irene R; Chernajovsky, Yuti; Gould, David; Noël, Danièle; Andrades, José A; Becerra, José; Rubio, Nuria; Blanco, Jerónimo

    2009-10-01

    Non-invasive bioluminescence imaging (BLI) to monitor changes in gene expression of cells implanted in live animals should facilitate the development of biomaterial scaffolds for tissue regeneration. We show that, in vitro, induction of chondrogenic differentiation in mouse bone marrow stromal cell line (CL1) and human adipose tissue derived mesenchymal stromal cells (hAMSCs), permanently transduced with a procollagen II (COL2A1) promoter driving a firefly luciferase gene reporter (PLuc) (COL2A1p.PLuc), induces PLuc expression in correlation with increases in COL2A1 and Sox9 mRNA expression and acquisition of chondrocytic phenotype. To be able to simultaneously monitor in vivo cell differentiation and proliferation, COL2A1p.PLuc labelled cells were also genetically labelled with a renilla luciferase (RLuc) gene driven by a constitutively active cytomegalovirus promoter, and then seeded in demineralized bone matrix (DBM) subcutaneously implanted in SCID mice. Non-invasive BLI monitoring of the implanted mice showed that the PLuc/RLuc ratio reports on gene expression changes indicative of cell differentiation. Large (CL1) and moderated (hAMSCs) changes in the PLuc/RLuc ratio over a 6 week period, revealed different patterns of in vivo chondrogenic differentiation for the CL1 cell line and primary MSCs, in agreement with in vitro published data and our results from histological analysis of DBM sections. This double bioluminescence labelling strategy together with BLI imaging to analyze behaviour of cells implanted in live animals should facilitate the development of progenitor cell/scaffold combinations for tissue repair.

  10. Anatomic research on the perioral muscles, functional matrix of the maxillary and mandibular bones.

    PubMed

    D'Andrea, Emanuela; Barbaix, Erik

    2006-06-01

    The aim of this research was to study, on the basis of anatomic specimen, the insertion of and the existing correlation between the orbicularis oris, the perioral and the buccinator muscles. Dissections were performed on 40 embalmed caucasian specimens. The skin and the subcutaneous stratum were removed from the perioral zone starting from the base of the nose and the zygomatic arch down to the hyoid bone. The orbicularis oris and the facial muscles were isolated in the successive planes. In the more superficial layer, the following muscles were displayed: the orbicularis oris around the oral opening, the mentalis in the lower part, the transversus menti, the depressor anguli oris and the depressor labii inferioris, the risorius, and the zygomaticus major and minor positioned on the area of the labial commissure. The buccinator muscle was situated under this superficial stratum. In 85% of the specimens we found a fourth inferior band of the buccinator muscle that runs continuously from one side to the other of the mandible. This bundle always ran cranially to the foramen mentale. The findings have been compared with magnetic resonance images obtained from ten patients. One of the main findings was that the majority of these muscles were so densely interrelated that they could be considered parts of two functional units. A deep unit is composed of the buccinator muscle and the inner ring of the orbicularis oris and a superficial unit is built up by the depressor anguli oris, the zygomaticus, the risorius and the outer ring of the orbicularis oris. MR imaging confirmed these findings.

  11. Beyond the functional matrix hypothesis: a network null model of human skull growth for the formation of bone articulations.

    PubMed

    Esteve-Altava, Borja; Rasskin-Gutman, Diego

    2014-09-01

    Craniofacial sutures and synchondroses form the boundaries among bones in the human skull, providing functional, developmental and evolutionary information. Bone articulations in the skull arise due to interactions between genetic regulatory mechanisms and epigenetic factors such as functional matrices (soft tissues and cranial cavities), which mediate bone growth. These matrices are largely acknowledged for their influence on shaping the bones of the skull; however, it is not fully understood to what extent functional matrices mediate the formation of bone articulations. Aiming to identify whether or not functional matrices are key developmental factors guiding the formation of bone articulations, we have built a network null model of the skull that simulates unconstrained bone growth. This null model predicts bone articulations that arise due to a process of bone growth that is uniform in rate, direction and timing. By comparing predicted articulations with the actual bone articulations of the human skull, we have identified which boundaries specifically need the presence of functional matrices for their formation. We show that functional matrices are necessary to connect facial bones, whereas an unconstrained bone growth is sufficient to connect non-facial bones. This finding challenges the role of the brain in the formation of boundaries between bones in the braincase without neglecting its effect on skull shape. Ultimately, our null model suggests where to look for modified developmental mechanisms promoting changes in bone growth patterns that could affect the development and evolution of the head skeleton.

  12. Beyond the functional matrix hypothesis: a network null model of human skull growth for the formation of bone articulations

    PubMed Central

    Esteve-Altava, Borja; Rasskin-Gutman, Diego

    2014-01-01

    Craniofacial sutures and synchondroses form the boundaries among bones in the human skull, providing functional, developmental and evolutionary information. Bone articulations in the skull arise due to interactions between genetic regulatory mechanisms and epigenetic factors such as functional matrices (soft tissues and cranial cavities), which mediate bone growth. These matrices are largely acknowledged for their influence on shaping the bones of the skull; however, it is not fully understood to what extent functional matrices mediate the formation of bone articulations. Aiming to identify whether or not functional matrices are key developmental factors guiding the formation of bone articulations, we have built a network null model of the skull that simulates unconstrained bone growth. This null model predicts bone articulations that arise due to a process of bone growth that is uniform in rate, direction and timing. By comparing predicted articulations with the actual bone articulations of the human skull, we have identified which boundaries specifically need the presence of functional matrices for their formation. We show that functional matrices are necessary to connect facial bones, whereas an unconstrained bone growth is sufficient to connect non-facial bones. This finding challenges the role of the brain in the formation of boundaries between bones in the braincase without neglecting its effect on skull shape. Ultimately, our null model suggests where to look for modified developmental mechanisms promoting changes in bone growth patterns that could affect the development and evolution of the head skeleton. PMID:24975579

  13. Matrix-mediated retention of osteogenic differentiation potential by human adult bone marrow stromal cells during ex vivo expansion.

    PubMed

    Mauney, Joshua R; Kaplan, David L; Volloch, Vladimir

    2004-07-01

    During prolonged cultivation ex vivo, adult bone marrow stromal stem cells (BMSCs) undergo two probably interdependent processes, replicative aging and a decline in differentiation potential. Recently, our results with primary human fibroblasts indicated that growth on denatured collagen (DC) matrix results in the reduction of the rate of cellular aging. The present study has been undertaken to test whether the growth of human BMSCs under the same conditions would translate into preservation of cellular aging-attenuated functions, such as the ability to express HSP70 in response to stress as well as of osteogenic differentiation potential. We report here that growth of BMSCs on a DC matrix versus tissue culture polystyrene significantly reduced one of the main manifestations of cellular aging, the attenuation of the ability to express a major protective stress response component, HSP70, increased the proliferation capacity of ex vivo expanded BMSCs, reduced the rate of morphological changes, and resulted in a dramatic increase in the retention of the potential to express osteogenic-specific functions and markers upon treatment with osteogenic stimulants. BMSCs are a promising and increasingly important cell source for tissue engineering as well as cell and gene therapeutic strategies. For use of BMSCs in these applications, ex vivo expansion is necessary to obtain a sufficient, therapeutically useful, number of cells; however, this results in the loss of differentiation potential. This problem is especially acute in older patients where more extensive in vitro expansion of smaller number of stem/progenitor cells is needed. The finding that growth on certain biomaterials preserves aging-attenuated functions, enhances proliferation capacity, and maintains differentiation potential of BMSCs indicates a promising approach to address this problem.

  14. Contribution of human osteoblasts and macrophages to bone matrix degradation and proinflammatory cytokine release after exposure to abrasive endoprosthetic wear particles

    PubMed Central

    Jonitz-Heincke, Anika; Lochner, Katrin; Schulze, Christoph; Pohle, Diana; Pustlauk, Wera; Hansmann, Doris; Bader, Rainer

    2016-01-01

    One of the major reasons for failure after total joint arthroplasty is aseptic loosening of the implant. At articulating surfaces, defined as the interface between implant and surrounding bone cement, wear particles can be generated and released into the periprosthetic tissue, resulting in inflammation and osteolysis. The aim of the present study was to evaluate the extent to which osteoblasts and macrophages are responsible for the osteolytic and inflammatory reactions following contact with generated wear particles from Ti-6Al-7Nb and Co-28Cr-6Mo hip stems. To this end, human osteoblasts and THP-1 monocytic cells were incubated with the experimentally generated wear particles as well as reference particles (0.01 and 0.1 mg/ml) for 48 h under standard culture conditions. To evaluate the impact of these particles on the two cell types, the release of different bone matrix degrading matrix metalloproteinases (MMPs), tissue inhibitors of MMPs (TIMPs), and relevant cytokines were determined by multiplex enzyme-linked immunosorbent assays. Following incubation with wear particles, human osteoblasts showed a significant upregulation of MMP1 and MMP8, whereas macrophages reacted with enhanced MMP3, MMP8 and MMP10 production. Moreover, the synthesis of TIMPs 1 and 2 was inhibited. The osteoblasts and macrophages also responded with modified expression of the inflammatory mediators interleukin (IL)-6, IL-8, monocyte chemoattractant protein-1 and vascular endothelial growth factor. These results demonstrate that the release of wear particles affects the release of proinflammatory cytokines and has a negative impact on bone matrix formation during the first 48 h of particle exposure. Human osteoblasts are directly involved in the proinflammatory cascade of bone matrix degradation. The simultaneous activation and recruitment of monocytes/macrophages boosted osteolytic processes in the periprosthetic tissue. By the downregulation of TIMP production and the concomitant

  15. Intentional reim plantation of a tooth with severe periodontal involvement using enamel matrix derivative in combination with guided tissue regeneration and bone grafting: a case report.

    PubMed

    Sugai, Kenji; Sato, Shuichi; Suzuki, Kuniharu; Ito, Koichi

    2008-02-01

    This case involved the intentional reimplantation of a tooth with severe periodontal involvement using regenerative therapies. The maxillary left central incisor was intentionally extracted, enamel matrix derivative (EMD) was applied, and the tooth was repositioned accurately. The bone defect was filled with a xenograft and a demineralized freeze-dried bone allograft, and a guided tissue regeneration membrane was adapted over the site. After 5 years, a reduction in probing depth and a gain in clinical attachment were observed. Conventional radiographs and cone-beam computerized tomographs showed hard tissue improvement. Favorable clinical results were obtained with reimplantation with applied EMD, combined with regenerative therapies, for treating a tooth with severe periodontal involvement.

  16. Healing of periodontal defects treated with enamel matrix proteins and root surface conditioning--an experimental study in dogs.

    PubMed

    Sakallioğlu, Umur; Açikgöz, Gökhan; Ayas, Bülent; Kirtiloğlu, Tuğrul; Sakallioğlu, Eser

    2004-05-01

    Application of enamel matrix proteins has been introduced as an alternative method for periodontal regenerative therapy. It is claimed that this approach provides periodontal regeneration by a biological approach, i.e. creating a matrix on the root surfaces that promotes cementum, periodontal ligament (PDL) and alveolar bone regeneration, thus mimicking the events occurring during tooth development. Although there have been numerous in vitro and in vivo studies demonstrating periodontal regeneration, acellular cementum formation and clinical outcomes via enamel matrix proteins usage, their effects on the healing pattern of soft and hard periodontal tissues are not well-established and compared with root conditioning alone. In the present study, the effects of Emdogain (Biora, Malmö, Sweden), an enamel matrix derivative mainly composed of enamel matrix proteins (test), on periodontal wound healing were evaluated and compared with root surface conditioning (performed with 36% orthophosphoric acid) alone (control) histopathologically and histomorphometrically by means of the soft and hard tissue profile of periodontium. An experimental periodontitis model performed at premolar teeth of four dogs were used in the study and the healing pattern of periodontal tissues was evaluated at days 7, 14, 21, 28 (one dog at each day), respectively. At day 7, soft tissue attachment evaluated by means of connective tissue and/or epithelial attachment to the root surfaces revealed higher connective tissue attachment rate in the test group and the amount of new connective tissue proliferation in the test group was significantly greater than the control group (p<0.01). New bone formation by osteoconduction initiated at day 14 in the test and control group. At day 21, the orientation of supra-alveolar and PDL fibers established, and new cementum formation observed in both groups. At day 28, although regenerated cementum was cellular in all of the roots in the control samples, an

  17. Magnetically Responsive Bone Marrow Mesenchymal Stem Cell-Derived Smooth Muscle Cells Maintain Their Benefits to Augmenting Elastic Matrix Neoassembly.

    PubMed

    Swaminathan, Ganesh; Sivaraman, Balakrishnan; Moore, Lee; Zborowski, Maciej; Ramamurthi, Anand

    2016-04-01

    Abdominal aortic aneurysms (AAA) represent abnormal aortal expansions that result from chronic proteolytic breakdown of elastin and collagen fibers by matrix metalloproteases. Poor elastogenesis by adult vascular smooth muscle cells (SMCs) limits regenerative repair of elastic fibers, critical for AAA growth arrest. Toward overcoming these limitations, we recently demonstrated significant elastogenesis by bone marrow mesenchymal stem cell-derived SMCs (BM-SMCs) and their proelastogenesis and antiproteolytic effects on rat aneurysmal SMCs (EaRASMCs). We currently investigate the effects of super paramagnetic iron oxide nanoparticle (SPION) labeling of BM-SMCs, necessary to magnetically guide them to the AAA wall, on their functional benefits. Our results indicate that SPION-labeling is noncytotoxic and does not adversely impact the phenotype and elastogenesis by BM-SMCs. In addition, SPION-BM-SMCs showed no changes in the ability of the BM-SMCs to stimulate elastin regeneration and attenuate proteolytic activity by EaRASMCs. Together, our results are promising toward the utility of SPIONs for magnetic targeting of BM-SMCs for in situ AAA regenerative repair. PMID:26830683

  18. Mineralization defects in cementum and craniofacial bone from loss of bone sialoprotein.

    PubMed

    Foster, B L; Ao, M; Willoughby, C; Soenjaya, Y; Holm, E; Lukashova, L; Tran, A B; Wimer, H F; Zerfas, P M; Nociti, F H; Kantovitz, K R; Quan, B D; Sone, E D; Goldberg, H A; Somerman, M J

    2015-09-01

    Bone sialoprotein (BSP) is a multifunctional extracellular matrix protein found in mineralized tissues, including bone, cartilage, tooth root cementum (both acellular and cellular types), and dentin. In order to define the role BSP plays in the process of biomineralization of these tissues, we analyzed cementogenesis, dentinogenesis, and osteogenesis (intramembranous and endochondral) in craniofacial bone in Bsp null mice and wild-type (WT) controls over a developmental period (1-60 days post natal; dpn) by histology, immunohistochemistry, undecalcified histochemistry, microcomputed tomography (microCT), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and quantitative PCR (qPCR). Regions of intramembranous ossification in the alveolus, mandible, and calvaria presented delayed mineralization and osteoid accumulation, assessed by von Kossa and Goldner's trichrome stains at 1 and 14 dpn. Moreover, Bsp(-/-) mice featured increased cranial suture size at the early time point, 1 dpn. Immunostaining and PCR demonstrated that osteoblast markers, osterix, alkaline phosphatase, and osteopontin were unchanged in Bsp null mandibles compared to WT. Bsp(-/-) mouse molars featured a lack of functional acellular cementum formation by histology, SEM, and TEM, and subsequent loss of Sharpey's collagen fiber insertion into the tooth root structure. Bsp(-/-) mouse alveolar and mandibular bone featured equivalent or fewer osteoclasts at early ages (1 and 14 dpn), however, increased RANKL immunostaining and mRNA, and significantly increased number of osteoclast-like cells (2-5 fold) were found at later ages (26 and 60 dpn), corresponding to periodontal breakdown and severe alveolar bone resorption observed following molar teeth entering occlusion. Dentin formation was unperturbed in Bsp(-/-) mouse molars, with no delay in mineralization, no alteration in dentin dimensions, and no differences in odontoblast markers analyzed. No defects were identified in

  19. Mineralization defects in cementum and craniofacial bone from loss of bone sialoprotein.

    PubMed

    Foster, B L; Ao, M; Willoughby, C; Soenjaya, Y; Holm, E; Lukashova, L; Tran, A B; Wimer, H F; Zerfas, P M; Nociti, F H; Kantovitz, K R; Quan, B D; Sone, E D; Goldberg, H A; Somerman, M J

    2015-09-01

    Bone sialoprotein (BSP) is a multifunctional extracellular matrix protein found in mineralized tissues, including bone, cartilage, tooth root cementum (both acellular and cellular types), and dentin. In order to define the role BSP plays in the process of biomineralization of these tissues, we analyzed cementogenesis, dentinogenesis, and osteogenesis (intramembranous and endochondral) in craniofacial bone in Bsp null mice and wild-type (WT) controls over a developmental period (1-60 days post natal; dpn) by histology, immunohistochemistry, undecalcified histochemistry, microcomputed tomography (microCT), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and quantitative PCR (qPCR). Regions of intramembranous ossification in the alveolus, mandible, and calvaria presented delayed mineralization and osteoid accumulation, assessed by von Kossa and Goldner's trichrome stains at 1 and 14 dpn. Moreover, Bsp(-/-) mice featured increased cranial suture size at the early time point, 1 dpn. Immunostaining and PCR demonstrated that osteoblast markers, osterix, alkaline phosphatase, and osteopontin were unchanged in Bsp null mandibles compared to WT. Bsp(-/-) mouse molars featured a lack of functional acellular cementum formation by histology, SEM, and TEM, and subsequent loss of Sharpey's collagen fiber insertion into the tooth root structure. Bsp(-/-) mouse alveolar and mandibular bone featured equivalent or fewer osteoclasts at early ages (1 and 14 dpn), however, increased RANKL immunostaining and mRNA, and significantly increased number of osteoclast-like cells (2-5 fold) were found at later ages (26 and 60 dpn), corresponding to periodontal breakdown and severe alveolar bone resorption observed following molar teeth entering occlusion. Dentin formation was unperturbed in Bsp(-/-) mouse molars, with no delay in mineralization, no alteration in dentin dimensions, and no differences in odontoblast markers analyzed. No defects were identified in

  20. Mineralization defects in cementum and craniofacial bone from loss of bone sialoprotein

    PubMed Central

    Foster, B.L.; Ao, M.; Willoughby, C.; Soenjaya, Y.; Holm, E.; Lukashova, L.; Tran, A. B.; Wimer, H.F.; Zerfas, P.M.; Nociti, F.H.; Kantovitz, K.R.; Quan, B.D.; Sone, E.D.; Goldberg, H.A.; Somerman, M.J.

    2015-01-01

    Bone sialoprotein (BSP) is a multifunctional extracellular matrix protein found in mineralized tissues, including bone, cartilage, tooth root cementum (both acellular and cellular types), and dentin. In order to define the role BSP plays in the process of biomineralization of these tissues, we analyzed cementogenesis, dentinogenesis, and osteogenesis (intramembranous and endochondral) in craniofacial bone in Bsp null mice and wild-type (WT) controls over a developmental period (1-60 days post natal; dpn) by histology, immunohistochemistry, undecalcified histochemistry, microcomputed tomography (microCT), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and quantitative PCR (qPCR). Regions of intramembranous ossification in the alveolus, mandible, and calvaria presented delayed mineralization and osteoid accumulation, assessed by von Kossa and Goldner's trichrome stains at 1 and 14 dpn. Moreover, Bsp−/− mice featured increased cranial suture size at the early time point, 1 dpn. Immunostaining and PCR demonstrated that osteoblast markers, osterix, alkaline phosphatase, and osteopontin were unchanged in Bsp null mandibles compared to WT. Bsp−/− mouse molars featured a lack of functional acellular cementum formation by histology, SEM, and TEM, and subsequent loss of Sharpey's collagen fiber insertion into the tooth root structure. Bsp−/− mouse alveolar and mandibular bone featured equivalent or fewer osteoclasts at early ages (1 and 14 dpn), however, increased RANKL immunostaining and mRNA, and significantly increased number of osteoclast-like cells (2-5 fold) were found at later ages (26 and 60 dpn), corresponding to periodontal breakdown and severe alveolar bone resorption observed following molar teeth entering occlusion. Dentin formation was unperturbed in Bsp−/− mouse molars, with no delay in mineralization, no alteration in dentin dimensions, and no differences in odontoblast markers analyzed. No defects were identified

  1. Adjuvant neurotrophic factors in peripheral nerve repair with chondroitin sulfate proteoglycan-reduced acellular nerve allografts

    PubMed Central

    Boyer, Richard B.; Sexton, Kevin W.; Rodriguez-Feo, Charles L.; Nookala, Ratnam; Pollins, Alonda C.; Cardwell, Nancy L.; Tisdale, Keonna Y.; Nanney, Lillian B.; Shack, R. Bruce; Thayer, Wesley P.

    2014-01-01

    Background Acellular nerve allografts are now standard tools in peripheral nerve repair due to decreased donor site morbidity and operative time savings. Preparation of nerve allografts involves several steps of decellularization and modification of extracellular matrix to remove chondroitin sulfate proteoglycans (CSPGs), which have been shown to inhibit neurite outgrowth through a poorly understood mechanism involving RhoA and ECM-integrin interactions. Chondroitinase ABC (ChABC) is an enzyme that degrades CSPG molecules and has been shown to promote neurite outgrowth following injury of the central and peripheral nervous systems. Variable results following chondroitinase ABC treatment make it difficult to predict the effects of this drug in human nerve allografts, especially in the presence of native extracellular signaling molecules. Several studies have shown cross-talk between neurotrophic factor and CSPG signaling pathways, but their interaction remains poorly understood. In this study, we examined the adjuvant effects of nerve growth factor (NGF) and glial cell line-derived neurotrophic factor (GDNF) on neurite outgrowth post-injury in CSPG-reduced substrates and acellular nerve allografts. Materials and Methods E12 chicken DRG explants were cultured in medium containing ChABC, ChABC + NGF, ChABC + GDNF or control media. Explants were imaged at 3 d and neurite outgrowths measured. The rat sciatic nerve injury model involved a 1-cm sciatic nerve gap that was microsurgically repaired with ChABC pre-treated acellular nerve allografts. Prior to implantation, nerve allografts were incubated in NGF, GDNF or sterile water. Nerve histology was evaluated at 5d and 8wk post-injury. Results The addition of GDNF in vitro produced significant increase in sensory neurite length at 3 d compared to ChABC alone (P < 0.01), while NGF was not significantly different from control. In vivo adjuvant NGF produced increases in total myelinated axon count (P < 0.005) and motor axon

  2. Challenges to acellular biological scaffold mediated skeletal muscle tissue regeneration.

    PubMed

    Corona, Benjamin T; Greising, Sarah M

    2016-10-01

    Volumetric muscle loss (VML) injuries present a complex and heterogeneous clinical problem that results in a chronic loss of muscle tissue and strength. The primary limitation to muscle tissue regeneration after VML injury is the frank loss of all native muscle constituents in the defect, especially satellite cells and the basal lamina. Recent advancements in regenerative medicine have set forth encouraging and emerging translational and therapeutic options for these devastating injuries including the surgical implantation of acellular biological scaffolds. While these biomaterials can modulate the wound environment, the existing data do not support their capacity to promote appreciable muscle fiber regeneration that can contribute to skeletal muscle tissue functional improvements. An apparent restriction of endogenous satellite cell (i.e., pax7(+)) migration to acellular biological scaffolds likely underlies this deficiency. This work critically evaluates the role of an acellular biological scaffold in orchestrating skeletal muscle tissue regeneration, specifically when used as a regenerative medicine approach for VML injury. PMID:27472161

  3. Challenges to acellular biological scaffold mediated skeletal muscle tissue regeneration.

    PubMed

    Corona, Benjamin T; Greising, Sarah M

    2016-10-01

    Volumetric muscle loss (VML) injuries present a complex and heterogeneous clinical problem that results in a chronic loss of muscle tissue and strength. The primary limitation to muscle tissue regeneration after VML injury is the frank loss of all native muscle constituents in the defect, especially satellite cells and the basal lamina. Recent advancements in regenerative medicine have set forth encouraging and emerging translational and therapeutic options for these devastating injuries including the surgical implantation of acellular biological scaffolds. While these biomaterials can modulate the wound environment, the existing data do not support their capacity to promote appreciable muscle fiber regeneration that can contribute to skeletal muscle tissue functional improvements. An apparent restriction of endogenous satellite cell (i.e., pax7(+)) migration to acellular biological scaffolds likely underlies this deficiency. This work critically evaluates the role of an acellular biological scaffold in orchestrating skeletal muscle tissue regeneration, specifically when used as a regenerative medicine approach for VML injury.

  4. Aseptic versus Sterile Acellular Dermal Matrices in Breast Reconstruction: An Updated Review

    PubMed Central

    Mendenhall, Shaun D.; Neumeister, Michael W.; Cederna, Paul S.; Momoh, Adeyiza O.

    2016-01-01

    Background: As the use of acellular dermal matrices in breast reconstruction has become more commonplace and efforts are made to improve on postoperative outcomes, the method of acellular dermal matrix (ADM) processing (aseptic versus sterile) has become a subject of interest. This article provides an updated overview of the critical aspects of ADM processing in addition to application of ADMs in single- and two-stage breast reconstruction, a review of the morbidity associated with ADM use, and alternatives. Methods: A literature review was performed in PubMed identifying recent systematic reviews, meta-analyses, and head-to-head comparisons on aseptically processed ADM and sterile-processed ADM in implant-based breast reconstruction. Results: Recent meta-analyses have shown a 2- to 3-fold increase in infections and tissue expander/implant explantation rates and a 3- to 4-fold increase in seroma formation compared with non-ADM reconstruction techniques. Comparisons of aseptic and sterile ADMs in multiple studies have shown no significant difference in infection rates and equivocal findings for other specific complications such as seroma formation. Conclusions: Current evidence on the impact of processing techniques that improve ADM sterility on postoperative morbidity in implant breast reconstruction is unclear. Deficiencies of the available data highlight the need for well-designed, multicenter, randomized controlled studies that will aid in optimizing outcomes in implant-based breast reconstruction. PMID:27536502

  5. Sterile acellular dermal collagen as a treatment for rippling deformity of breast.

    PubMed

    Busse, Brittany; Orbay, Hakan; Sahar, David E

    2014-01-01

    Prosthetic implants are frequently used for breast augmentation and breast reconstruction following mastectomy. Unfortunately, long-term aesthetic results of prosthetic breast restoration may be hindered by complications such as rippling, capsular contracture, and implant malposition. The advent of use of acellular dermal matrices has greatly improved the outcomes of prosthetic breast reconstruction. We describe a case of rippling deformity of breast that was treated using an acellular dermal matrix product, AlloMax. The patient presented with visible rippling of bilateral prosthetic breast implants as well as significant asymmetry of the breasts after multiple excisional biopsies for right breast ductal carcinoma in situ. A 6 × 10 cm piece of AlloMax was placed on the medial aspect of each breast between the implant and the skin flap. Follow-up was performed at 1 week, 3 months, and 1 year following the procedure. The patient recovered well from the surgery and there were no complications. At her first postoperative follow-up the patient was extremely satisfied with the result. At her 3-month and 1-year follow-up she had no recurrence of her previous deformity and no new deformity. PMID:25610697

  6. Long-term voluntary exercise of male mice induces more beneficial effects on cancellous and cortical bone than on the collagenous matrix.

    PubMed

    Isaksson, Hanna; Tolvanen, Viivi; Finnilä, Mikko A J; Iivarinen, Jarkko; Turunen, Antti; Silvast, Tuomo S; Tuukkanen, Juha; Seppänen, Kari; Arokoski, Jari P A; Brama, Pieter A; Jurvelin, Jukka S; Helminen, Heikki J

    2009-11-01

    The effects of lifelong physical exercise on the composition, structure and mechanical properties of bone are not well understood. Earlier, we found that voluntary physical exercise improved various properties of bone in maturing male mice up to 6 months of age. In this study, we extended the previous study to 18 months. Half of the mice (total N=144) had access to running wheels while half were kept sedentary. The collagen network was assessed biochemically and by tensile testing of decalcified bone. The mineralized femur was analyzed with pQCT and three-point-bending of the diaphysis and neck-strength-test. The proximal tibia was analyzed with microCT. The bone collagen revealed inferior tensional properties with aging and the mineralized femur demonstrated decreased stiffness with age. In the running mice, tensile properties and the BMD were reduced at 18 months of age compared to the sedentary mice. In contrast, the stiffness of both the diaphysis and femoral neck was higher, and trabecular architecture and structure were improved in the running mice. In summary, the results suggest that lifelong exercise training of male mice results in more beneficial effects on intact mineralized bone in both the diaphysis and epiphysis than on bone collagenous matrix.

  7. Pattern of mineralization after regenerative periodontal therapy with enamel matrix proteins.

    PubMed

    Bosshardt, Dieter D; Sculean, Anton; Donos, Nikolaos; Lang, Niklaus P

    2006-05-01

    A derivative (EMD) of enamel matrix proteins (EMPs) is used for periodontal regeneration because EMPs are believed to induce the formation of acellular extrinsic fiber cementum (AEFC). Other reports, however, indicate that EMPs have osteogenic potential. The aim of this study was to characterize the nature of the tissue that forms on the root surface following application of EMD. Ten human teeth affected by periodontitis and scheduled for extraction were treated with EMD. Four to six weeks later, they were extracted and processed for analysis by light microscopy and transmission electron microscopy. Immunocytochemistry with antibodies against bone sialoprotein (BSP) and osteopontin (OPN) was performed to determine the mineralization pattern. The newly formed tissues on the root were thick and contained embedded cells. Small mineralization foci were regularly seen, and large organic matrix patches were occasionally seen, but a distinct mineralization front was lacking. While labeling for BSP was always associated with small mineralization foci and large matrix patches, OPN labeling was seen inconsistently. It is concluded that tissues resembling either cellular intrinsic fiber cementum or a type of bone were observed. The mineralization pattern mostly resembled that found in bone, except for a few areas that exhibited a hitherto undescribed mineralization pattern. PMID:16674690

  8. Bone mineral (31)P and matrix-bound water densities measured by solid-state (31)P and (1)H MRI.

    PubMed

    Seifert, Alan C; Li, Cheng; Rajapakse, Chamith S; Bashoor-Zadeh, Mahdieh; Bhagat, Yusuf A; Wright, Alexander C; Zemel, Babette S; Zavaliangos, Antonios; Wehrli, Felix W

    2014-07-01

    Bone is a composite material consisting of mineral and hydrated collagen fractions. MRI of bone is challenging because of extremely short transverse relaxation times, but solid-state imaging sequences exist that can acquire the short-lived signal from bone tissue. Previous work to quantify bone density via MRI used powerful experimental scanners. This work seeks to establish the feasibility of MRI-based measurement on clinical scanners of bone mineral and collagen-bound water densities, the latter as a surrogate of matrix density, and to examine the associations of these parameters with porosity and donors' age. Mineral and matrix-bound water images of reference phantoms and cortical bone from 16 human donors, aged 27-97 years, were acquired by zero-echo-time 31-phosphorus ((31)P) and 1-hydrogen ((1)H) MRI on whole body 7T and 3T scanners, respectively. Images were corrected for relaxation and RF inhomogeneity to obtain density maps. Cortical porosity was measured by micro-computed tomography (μCT), and apparent mineral density by peripheral quantitative CT (pQCT). MRI-derived densities were compared to X-ray-based measurements by least-squares regression. Mean bone mineral (31)P density was 6.74 ± 1.22 mol/l (corresponding to 1129 ± 204 mg/cc mineral), and mean bound water (1)H density was 31.3 ± 4.2 mol/l (corresponding to 28.3 ± 3.7 %v/v). Both (31)P and bound water (BW) densities were correlated negatively with porosity ((31)P: R(2) = 0.32, p < 0.005; BW: R(2) = 0.63, p < 0.0005) and age ((31)P: R(2) = 0.39, p < 0.05; BW: R(2) = 0.70, p < 0.0001), and positively with pQCT density ((31)P: R(2) = 0.46, p < 0.05; BW: R(2) = 0.50, p < 0.005). In contrast, the bone mineralization ratio (expressed here as the ratio of (31)P density to bound water density), which is proportional to true bone mineralization, was found to be uncorrelated with porosity, age or pQCT density. This work establishes the feasibility of image-based quantification of bone mineral and bound

  9. Inkjet-Based Biopatterning of Bone Morphogenetic Protein-2 to Spatially Control Calvarial Bone Formation

    PubMed Central

    Miller, Eric D.; DeCesare, Gary E.; Usas, Arvydas; Lensie, Emily L.; Bykowski, Michael R.; Huard, Johnny; Weiss, Lee E.; Losee, Joseph E.; Campbell, Phil G.

    2010-01-01

    The purpose of this study was to demonstrate spatial control of osteoblast differentiation in vitro and bone formation in vivo using inkjet bioprinting technology and to create three-dimensional persistent bio-ink patterns of bone morphogenetic protein-2 (BMP-2) and its modifiers immobilized within microporous scaffolds. Semicircular patterns of BMP-2 were printed within circular DermaMatrix™ human allograft scaffold constructs. The contralateral halves of the constructs were unprinted or printed with BMP-2 modifiers, including the BMP-2 inhibitor, noggin. Printed bio-ink pattern retention was validated using fluorescent or 125I-labeled bio-inks. Mouse C2C12 progenitor cells cultured on patterned constructs differentiated in a dose-dependent fashion toward an osteoblastic fate in register to BMP-2 patterns. The fidelity of spatial restriction of osteoblastic differentiation at the boundary between neighboring BMP-2 and noggin patterns improved in comparison with patterns without noggin. Acellular DermaMatrix constructs similarly patterned with BMP-2 and noggin were then implanted into a mouse calvarial defect model. Patterns of bone formation in vivo were comparable with patterned responses of osteoblastic differentiation in vitro. These results demonstrate that three-dimensional biopatterning of a growth factor and growth factor modifier within a construct can direct cell differentiation in vitro and tissue formation in vivo in register to printed patterns. PMID:20028232

  10. Extracellular matrix mineralization in murine MC3T3-E1 osteoblast cultures: an ultrastructural, compositional and comparative analysis with mouse bone.

    PubMed

    Addison, W N; Nelea, V; Chicatun, F; Chien, Y-C; Tran-Khanh, N; Buschmann, M D; Nazhat, S N; Kaartinen, M T; Vali, H; Tecklenburg, M M; Franceschi, R T; McKee, M D

    2015-02-01

    Bone cell culture systems are essential tools for the study of the molecular mechanisms regulating extracellular matrix mineralization. MC3T3-E1 osteoblast cell cultures are the most commonly used in vitro model of bone matrix mineralization. Despite the widespread use of this cell line to study biomineralization, there is as yet no systematic characterization of the mineral phase produced in these cultures. Here we provide a comprehensive, multi-technique biophysical characterization of this cell culture mineral and extracellular matrix, and compare it to mouse bone and synthetic apatite mineral standards, to determine the suitability of MC3T3-E1 cultures for biomineralization studies. Elemental compositional analysis by energy-dispersive X-ray spectroscopy (EDS) showed calcium and phosphorus, and trace amounts of sodium and magnesium, in both biological samples. X-ray diffraction (XRD) on resin-embedded intact cultures demonstrated that similar to 1-month-old mouse bone, apatite crystals grew with preferential orientations along the (100), (101) and (111) mineral planes indicative of guided biogenic growth as opposed to dystrophic calcification. XRD of crystals isolated from the cultures revealed that the mineral phase was poorly crystalline hydroxyapatite with 10 to 20nm-sized nanocrystallites. Consistent with the XRD observations, electron diffraction patterns indicated that culture mineral had low crystallinity typical of biological apatites. Fourier-transform infrared spectroscopy (FTIR) confirmed apatitic carbonate and phosphate within the biological samples. With all techniques utilized, cell culture mineral and mouse bone mineral were remarkably similar. Scanning (SEM) and transmission (TEM) electron microscopy showed that the cultures had a dense fibrillar collagen matrix with small, 100nm-sized, collagen fibril-associated mineralization foci which coalesced to form larger mineral aggregates, and where mineralized sites showed the accumulation of the

  11. Transplantation of allogenic chondrocytes with chitosan hydrogel-demineralized bone matrix hybrid scaffold to repair rabbit cartilage injury.

    PubMed

    Man, Zhentao; Hu, Xiaoqing; Liu, Zhenlong; Huang, Hongjie; Meng, Qingyang; Zhang, Xin; Dai, Linghui; Zhang, Jiying; Fu, Xin; Duan, Xiaoning; Zhou, Chunyan; Ao, Yingfang

    2016-11-01

    Cartilage tissue engineering is the hotspot of cartilage repair. The allogenic chondrocytes appear to be a promising source of seed cells in cartilage tissue engineering. In this study, we aimed to transplant allogenic chondrocytes with chitosan hydrogel (CS)-demineralized bone matrix (DBM) hybrid scaffold (CS/DBM) to repair rabbit cartilage injury with one-step operation. After the CS/DBM scaffold was successfully fabricated, it showed that the porous CS filled the large pores of DBM, which improved the distribution of seed cells in the CS/DBM scaffold. The allogenic chondrocytes at second passage were transplanted with different scaffolds to repair rabbit cartilage injury. Twenty-four weeks after surgery, the cartilage defect in the CS/DBM group was successfully filled as shown by MRI. Moreover, the histological score of CS/DBM group was significantly higher than that of the other groups. On the aspect of biomechanical property, the regenerated cartilage in the CS/DBM group were superior to those in the other groups as determined by nanoindentation. Meanwhile, no obvious inflammatory response was observed after the transplantation of allogenic chondrocytes at 24 weeks post-surgery. Furtherly, gene expression profile for cells within the repair tissue was compared with the allogenic chondrocytes before transplantation using Agilent microarray and RT-qPCR. The results showed that some genes beneficial to cartilage regeneration, such as BMP-7, HGF, and IGF-1, were upregulated one month after transplantation. Consequently, our study demonstrated that the transplantation of allogenic chondrocytes with CS/DBM scaffold successfully repaired rabbit cartilage injury with only one-step operation, thereby providing new insights into cartilage tissue engineering. PMID:27636153

  12. Extracellular matrix production by nucleus pulposus and bone marrow stem cells in response to altered oxygen and glucose microenvironments.

    PubMed

    Naqvi, Syeda M; Buckley, Conor T

    2015-12-01

    Bone marrow (BM) stem cells may be an ideal source of cells for intervertebral disc (IVD) regeneration. However, the harsh biochemical microenvironment of the IVD may significantly influence the biological and metabolic vitality of injected stem cells and impair their repair potential. This study investigated the viability and production of key matrix proteins by nucleus pulposus (NP) and BM stem cells cultured in the typical biochemical microenvironment of the IVD consisting of altered oxygen and glucose concentrations. Culture-expanded NP cells and BM stem cells were encapsulated in 1.5% alginate and ionically crosslinked to form cylindrical hydrogel constructs. Hydrogel constructs were maintained under different glucose concentrations (1, 5 and 25 mM) and external oxygen concentrations (5 and 20%). Cell viability was measured using the Live/Dead® assay and the production of sulphated glycosaminoglycans (sGAG), and collagen was quantified biochemically and histologically. For BM stem cells, IVD-like micro-environmental conditions (5 mM glucose and 5% oxygen) increased the accumulation of sGAG and collagen. In contrast, low glucose conditions (1 mM glucose) combined with 5% external oxygen concentration promoted cell death, inhibiting proliferation and the accumulation of sGAG and collagen. NP-encapsulated alginate constructs were relatively insensitive to oxygen concentration or glucose condition in that they accumulated similar amounts of sGAG under all conditions. Under IVD-like microenvironmental conditions, NP cells were found to have a lower glucose consumption rate compared with BM cells and may in fact be more suitable to adapt and sustain the harsh microenvironmental conditions. Considering the highly specialised microenvironment of the central NP, these results indicate that IVD-like concentrations of low glucose and low oxygen are critical and influential for the survival and biological behaviour of stem cells. Such findings may promote and accelerate

  13. Tissue Regeneration of the Vocal Fold Using Bone Marrow Mesenchymal Stem Cells and Synthetic Extracellular Matrix Injections in Rats

    PubMed Central

    Johnson, Beatriz Helena Quinchia; Fox, Ryan; Chen, Xia; Thibeault, Susan

    2009-01-01

    Objective To determine the effectiveness of bone marrow mesenchymal stem cell (BM-MSC) transplantation in isolation or within a synthetic extracellular matrix (sECM) for tissue regeneration of the scarred vocal fold lamina propria. Methods In vitro stability and compatibility of mouse BM-MSC embedded in sECM was assessed by flow cytometry detection of BM-MSC marker expression and proliferation. Eighteen rats were subjected to vocal fold injury bilaterally, followed by one month post-treatment with unilateral injections of saline or sECM hydrogel (Extracel), GFP-mouse BM-MSC or BM-MSC suspended in sECM. Outcomes measured one month after treatment included procollagen-III, fibronectin, hyaluronan synthase-III (HAS3), hyaluronidase (HYAL3), smooth muscle actin (SMA) and transforming growth factor-beta 1(TGF-β1) mRNA expression. The persistence of GFP BM-MSC, proliferation, apoptosis and myofibroblast differentiation was assessed by immunofluorescence. Results BM-MSC grown in vitro within sECM express Sca-1, are positive for hyaluronan receptor CD44 and continue to proliferate. In the in vivo study, groups injected with BM-MSC had detectable GFP-labeled BM-MSC remaining, showed proliferation and low apoptotic or myofibroblast markers compared to the contralateral side. Embedded BM-MSC in sECM group exhibited increased levels of procollagen III, fibronectin and TGF-β1. BM-MSC within sECM downregulated the expression of SMA compared to BM-MSC alone, exhibited upregulation of HYAL3 and no change in HAS3 compared to saline. Conclusions Treatment of vocal fold scarring with BM-MSC injected in a sECM displayed the most favorable outcomes in ECM production, hyaluronan metabolism, myofibroblast differentiation and production of TGF-β1. Furthermore, the combined treatment had no detectable cytotoxicity and preserved local cell proliferation. PMID:20131370

  14. Overexpression of Runx2 directed by the matrix metalloproteinase-13 promoter containing the AP-1 and Runx/RD/Cbfa sites alters bone remodeling in vivo.

    PubMed

    Selvamurugan, Nagarajan; Jefcoat, Stephen C; Kwok, Sukyee; Kowalewski, Rodney; Tamasi, Joseph A; Partridge, Nicola C

    2006-10-01

    The activator protein-1 (AP-1) and runt domain binding (Runx/RD/Cbfa) sites and their respective binding proteins, c-Fos/c-Jun and Runx2 (Cbfa1), regulate the rat matrix metalloproteinase-13 (MMP-13) promoter in both parathyroid hormone (PTH)-treated and differentiating osteoblastic cells in culture. To determine the importance of these regulatory sites in the expression of MMP-13 in vivo, transgenic mice containing either wild-type (-456 or -148) or AP-1 and Runx/RD/Cbfa sites mutated (-148A3R3) MMP-13 promoters fused with the E. coli lacZ reporter were generated. The wild-type transgenic lines expressed higher levels of bacterial beta-galactosidase in bone, teeth, and skin compared to the mutant and non-transgenic lines. Next, we investigated if overexpression of Runx2 directed by the MMP-13 promoter regulated expression of bone specific genes in vivo, and whether this causes morphological changes in these animals. Real time RT-PCR experiments identified increased mRNA expression of bone forming genes and decreased MMP-13 in the tibiae of transgenic mice (14 days and 6 weeks old). Histomorphometric analyses of the proximal tibiae showed increased bone mineralization surface, mineral apposition rate, and bone formation rate in the transgenic mice which appears to be due to decreased osteoclast number. Since MMP-13 is likely to play a role in recruiting osteoclasts to the bone surface, decreased expression of MMP-13 may cause reduced osteoclast-mediated bone resorption, resulting in greater bone formation in transgenic mice. In summary, we show here that the 148 bp upstream of the MMP-13 transcriptional start site is sufficient and necessary for gene expression in bone, teeth, and skin in vivo and the AP-1 and Runx/RD/Cbfa sites are likely to regulate this. Overexpression of Runx2 by these regulatory elements appears to alter the balance between the bone formation-bone resorption processes in vivo. PMID:16639721

  15. Acellular Nerve Allografts in Peripheral Nerve Regeneration: A Comparative Study

    PubMed Central

    Moore, Amy M.; MacEwan, Matthew; Santosa, Katherine B.; Chenard, Kristofer E.; Ray, Wilson Z.; Hunter, Daniel A.; Mackinnon, Susan E.; Johnson, Philip J.

    2011-01-01

    Background Processed nerve allografts offer a promising alternative to nerve autografts in the surgical management of peripheral nerve injuries where short deficits exist. Methods Three established models of acellular nerve allograft (cold-preserved, detergent-processed, and AxoGen® -processed nerve allografts) were compared to nerve isografts and silicone nerve guidance conduits in a 14 mm rat sciatic nerve defect. Results All acellular nerve grafts were superior to silicone nerve conduits in support of nerve regeneration. Detergent-processed allografts were similar to isografts at 6 weeks post-operatively, while AxoGen®-processed and cold-preserved allografts supported significantly fewer regenerating nerve fibers. Measurement of muscle force confirmed that detergent-processed allografts promoted isograft-equivalent levels of motor recovery 16 weeks post-operatively. All acellular allografts promoted greater amounts of motor recovery compared to silicone conduits. Conclusions These findings provide evidence that differential processing for removal of cellular constituents in preparing acellular nerve allografts affects recovery in vivo. PMID:21660979

  16. Treatment of chondral defects of the knee with one step matrix-assisted technique enhanced by autologous concentrated bone marrow: in vitro characterisation of mesenchymal stem cells from iliac crest and subchondral bone.

    PubMed

    de Girolamo, Laura; Bertolini, Giulia; Cervellin, Matteo; Sozzi, Gabriella; Volpi, Piero

    2010-11-01

    Cartilage repair is still an unsolved problem. In the last years many cell-based treatments have been proposed, in order to obtain good regeneration of cartilage defects. The Autologous Matrix-Induced Chondrogenesis technique (AMIC(®)) combines the micro-fracture procedure with the use of a specific biological membrane. The phenotypic feature of bone marrow cell population, harvested from iliac crest and knee subchondral bone of patients treated with the AMIC(®) technique, enhanced by autologous concentrated bone marrow, was analysed to evaluate potential variations of the cell population. Samples of eleven patients, with isolated chondral lesions grade III or IV were treated with the AMIC(®) technique, enhanced by the use of autologous concentrated bone marrow. A small fraction of bone marrow samples, both from iliac crest and from the created micro-fractures, was analysed by FACS analysis and then cultured to verify their proliferative and differentiation potential. An average of 0.04% of concentrated bone marrow cells harvested from the iliac crest, presented mesenchymal stem cell phenotype (CD34(-)/CD45(low)/CD271(high)), whereas just 0.02% of these cells were identified from the samples harvested during the creation of micro-fractures at the knee. After two passages in culture, cells expressed a peculiar profile for MSC. Only MSC from bone marrow could be long-term propagated and were able to efficiently differentiate in the cultures. Although the AMIC(®) approach has many advantages, the surgical technique in the application of the microfracture technique remains essential and affects the final result.

  17. Hybrid chitosan/β-1,3-glucan matrix of bone scaffold enhances osteoblast adhesion, spreading and proliferation via promotion of serum protein adsorption.

    PubMed

    Przekora, Agata; Benko, Aleksandra; Blazewicz, Marta; Ginalska, Grazyna

    2016-01-01

    Initial protein adsorption to the material surface is crucial for osteoblast adhesion, survival, and rapid proliferation resulting in intensive new bone formation. The aim of this study was to demonstrate that modification of a chitosan matrix of chitosan/hydroxyapatite (chit/HA) biomaterial for bone tissue engineering applications with linear β-1,3-glucan (curdlan) leads to promotion of serum protein adsorption to the resultant scaffold (chit/glu/HA) and thus in enhancement of osteoblast adhesion, spreading and proliferation. Fabricated biomaterials were pre-adsorbed with different protein solutions and then protein adsorption and osteoblast behavior on the scaffolds were compared. Moreover, surface chemical composition, wettability and surface energy of biomaterials were compared. Modification of the chitosan matrix with β-1,3-glucan introduces a greater polarpart in the resultant chitosan/β-1,3-glucan matrix presumably resulting from more OH groups within the curdlan structure. Moreover, FTIR-ATR results suggest that there might be some sort of chemical interaction between the NH group of chitosan and the OH group of β-1,3-glucan. As a consequence, the chit/glu/HA scaffold adsorbs significantly more adhesion proteins that are crucial for osteoblasts compared to the chit/HA material, providing a higher density culture of well-spread osteoblasts on its surface. Obtained results revealed that not only is chit/glu/HA biomaterial a promising scaffold for bone tissue engineering applications, but the specific polysaccharide chit/glu matrix itself is promising for use in the biomedical material field to modify various biomaterials in order to enhance osteoblast adhesion and proliferation on their surfaces. PMID:27388048

  18. Incorporation of nanostructured hydroxyapatite and poly(N-isopropylacrylamide) in demineralized bone matrix enhances osteoblast and human mesenchymal stem cell activity.

    PubMed

    Nicoletti, Alessandro; Torricelli, Paola; Bigi, Adriana; Fornasari, Piermaria; Fini, Milena; Moroni, Lorenzo

    2015-01-01

    Demineralized bone matrix (DBM) is currently used in many clinical applications for bone augmentation and repair. DBM is normally characterized by the presence of bone morphogenetic proteins. In this study, the authors have optimized methods to obtain DBM under good manufacturing practice, resulting in enhanced bioactivity. The processed DBM can be used alone, together with nanostructured hydroxyapatite (nanoHA), or dispersed in a physiological carrier or hydrogel. In this study, osteoblasts (MG-63) and human bone marrow derived mesenchymal stem cells (hMSCs) were cultured on DBM pastes made in phosphate buffered saline solution or poly(N-isopropylacrylamide) (PNIPAAM) hydrogels with or without nanoHA. The authors observed that the presence of PNIPAAM reduced osteoblast adhesion, while the addition of nanoHA increased osteoblast adhesion, proliferation, interleukin-6 (IL-6) production, and reduced lactate dehydrogenase (LDH) production. Increasing concentrations of PNIPAAM in combination with nanoHA further increased osteoblast proliferation, and decreased IL-6 and LDH production. Incorporation of PNIPAAM in DBM enhanced hMSCs proliferation and collagen type-I production. Furthermore, a combination of PNIPAAM and nanoHA further increased alkaline phosphatase and osteocalcin production in hMSCs, independently from the concentration of PNIPAAM. This study shows that combinations of DBM with nanoHA and PNIPAAM seem to offer a promising route to enhance cell activity and induce osteogenic differentiation. PMID:26443012

  19. Silicon Matrix Calcium Phosphate as a Bone Substitute: Early Clinical and Radiological Results in a Prospective Study With 12-Month Follow-up

    PubMed Central

    Pesántez, Carlos Fernando Arias; Oliveira, Leonardo

    2008-01-01

    Introduction Autograft has been the “gold standard” for orthopedic bone grafting applications, but with some clinical challenges. Here we present the rationale and clinical outcomes supporting the use of a bone substitute material that consists of a mixture of two calcium phosphates (HA and ß-TCP), which are integrated into a silicon xerogel matrix, promoting nanocrystalline apatite layers on the surface of the material following implantation into a physiological environment. Methods Twenty-four patients with a median age of 53.80 (36–81) years underwent lumbar spinal fusion for degenerative disease, selected by clinical presentation, X-rays, and MRI findings. Subjects were evaluated preoperatively and postoperatively at 1, 3, 6, and 12 months. The outcome assessment consisted of visual analog scale (VAS), Oswestry Disability Index (ODI), and radiological assessment analyzing the state of fusion on X-ray and CT evaluation by 3 independent radiologists. Results All patients completed 12-month follow-up. The mean VAS decreased from 9.3 (± 0.9) to 2.4 (± 1.6) and the mean ODI decreased from 55.0 (± 9.2) to 19.3 (± 11.4) at 12-month follow-up. Three months after surgery, 10 patients (41.67%) had solid fusion based on analysis of CT scans and dynamic radiographs. At 6 months postoperatively, the fusion rate had increased to 75% (18 patients). Twelve months after surgery, 95.83% of patients had solid fusion (23 patients). Conclusions The clinical results from this study of silicon matrix calcium phosphate are consistent with previous in vitro studies indicating that this material stimulates formation of a bioactive layer and provides an effective bone graft material for lumbar fusion applications. In comparison with previous studies involving rhBMP-2, silicon matrix calcium phosphate provided a lower fusion rate at 3- and 6-month follow-up points, but after 12 months, the fusion rate was similar, with no statistical differences and lower overall costs. No

  20. In Vivo Confocal Microscopic Observation of Lamellar Corneal Transplantation in the Rabbit Using Xenogenic Acellular Corneal Scaffolds as a Substitute

    PubMed Central

    Feng, Yun; Wang, Wei

    2015-01-01

    Background: The limiting factor to corneal transplantation is the availability of donors. Research has suggested that xenogenic acellular corneal scaffolds (XACS) may be a possible alternative to transplantation. This study aimed to investigate the viability of performing lamellar corneal transplantation (LCT) in rabbits using canine XACS. Methods: Fresh dog corneas were decellularized by serial digestion, and LCT was performed on rabbit eyes using xenogeneic decellularized corneal matrix. Cellular and morphological changes were observed by slit-lamp, light, and scanning electron microscopy at 7, 30 and 90 days postoperatively. Immunocytochemical staining for specific markers such as keratin 3, vimentin and MUC5AC, was used to identify cells in the graft. Results: Decellularized xenogenic corneal matrix remained transparent for about 1-month after LCT. The recipient cells were able to survive and proliferate into the grafts. Three months after transplantation, grafts had merged with host tissue, and graft epithelialization and vascularization had occurred. Corneal nerve fibers were able to grow into the graft in rabbits transplanted with XACS. Conclusions: Xenogenic acellular corneal scaffolds can maintain the transparency of corneal grafts about 1-month and permit growth of cells and nerve fibers, and is, therefore, a potential substitute or carrier for a replacement cornea. PMID:25836615

  1. Comparison of toxicities of acellular pertussis vaccine with whole cell pertussis vaccine in experimental animals.

    PubMed

    Sato, Y; Sato, H

    1991-01-01

    There is no suitable animal model for pertussis encephalopathy in humans. In this study, we have compared the toxicity of acellular pertussis vaccine with whole cell pertussis vaccine in mice or guinea pigs. Two lots of acellular and two lots of whole cell vaccine produced in different countries were assayed in the test. 1. There was no statistical difference in mouse protective potency between these acellular or whole cell pertussis vaccines. 2. There were no differences in chemical ingredients between acellular and whole cell pertussis vaccines except for protein nitrogen content. The protein nitrogen content of whole cell vaccine was at least three times higher than that of the acellular product. 3. Anti-PT antibody productivity of the acellular vaccine was higher than that of the whole cell vaccine. 4. Anti-agglutinogen antibody productivity of the whole cell vaccine was higher than that of the acellular vaccine. 5. There was no pyrogenic activity with the acellular vaccine, but high pyrogenicity was seen with whole cell vaccine. 6. There was high body-weight decreasing toxicity in mice and guinea pigs by the whole cell vaccine. 7. The mice died when they received whole cell pertussis vaccine iv, but no deaths occurred in the mice which received acellular pertussis vaccine. PMID:1778317

  2. Nanopatterned acellular valve conduits drive the commitment of blood-derived multipotent cells

    PubMed Central

    Di Liddo, Rosa; Aguiari, Paola; Barbon, Silvia; Bertalot, Thomas; Mandoli, Amit; Tasso, Alessia; Schrenk, Sandra; Iop, Laura; Gandaglia, Alessandro; Parnigotto, Pier Paolo; Conconi, Maria Teresa; Gerosa, Gino

    2016-01-01

    Considerable progress has been made in recent years toward elucidating the correlation among nanoscale topography, mechanical properties, and biological behavior of cardiac valve substitutes. Porcine TriCol scaffolds are promising valve tissue engineering matrices with demonstrated self-repopulation potentiality. In order to define an in vitro model for investigating the influence of extracellular matrix signaling on the growth pattern of colonizing blood-derived cells, we cultured circulating multipotent cells (CMC) on acellular aortic (AVL) and pulmonary (PVL) valve conduits prepared with TriCol method and under no-flow condition. Isolated by our group from Vietnamese pigs before heart valve prosthetic implantation, porcine CMC revealed high proliferative abilities, three-lineage differentiative potential, and distinct hematopoietic/endothelial and mesenchymal properties. Their interaction with valve extracellular matrix nanostructures boosted differential messenger RNA expression pattern and morphologic features on AVL compared to PVL, while promoting on both matrices the commitment to valvular and endothelial cell-like phenotypes. Based on their origin from peripheral blood, porcine CMC are hypothesized in vivo to exert a pivotal role to homeostatically replenish valve cells and contribute to hetero- or allograft colonization. Furthermore, due to their high responsivity to extracellular matrix nanostructure signaling, porcine CMC could be useful for a preliminary evaluation of heart valve prosthetic functionality. PMID:27789941

  3. Osteoconductive properties of β-tricalcium phosphate matrix, polylactic and polyglycolic acid gel, and calcium phosphate cement in bone defects.

    PubMed

    Luvizuto, Eloá R; Queiroz, Thallita P; Margonar, Rogério; Panzarini, Sônia R; Hochuli-Vieira, Eduardo; Okamoto, Tetuo; Okamoto, Roberta

    2012-09-01

    Extensive bone defects in maxillofacial region can be corrected with autogenous grafts; otherwise, the disadvantages of the therapeutics modality take the research for new bone substitutes. The aim of the study was to evaluate and compare the osteoconductive properties of 3 commercial available biomaterials. A total of 30 calvarial defects (5-mm diameter) were randomly divided into 5 treatment groups, with a total of 6 defects per treatment group (n = 6). The treatment groups were as follows: 500 to 1000 μm β-tricalcium phosphate (β-TCP), polylactic and polyglycolic acid (PL/PG) gel, calcium phosphate cement, untreated control, and autograft control. The evaluations were based on histomorphometric analysis at 60 postoperative days. The results have shown that β-TCP and autograft control supported bone formation at 60 postoperative days. β-Tricalcium phosphate showed the highest amount of mineralized area per total area and statistically significant compared with PL/PG, calcium phosphate cement, and untreated control groups. The PL/PG gel does not have osteoconductive properties and performed similar to empty control. Calcium phosphate cement showed higher number of multinucleated giant cells around the sites of the biomaterial and showed newly formed bone only at the edges of the biomaterial, without bone formation within the biomaterial. The findings presented herein indicate that bone formation reached a maximum level when rat calvarial defects were filled with β-TCP at 60 postoperative days. Further studies should be conducted with β-TCP to understand the potential of this biomaterial in bone regeneration.

  4. The effect of SDF-1α on low dose BMP-2 mediated bone regeneration by release from heparinized mineralized collagen type I matrix scaffolds in a murine critical size bone defect model.

    PubMed

    Zwingenberger, Stefan; Langanke, Robert; Vater, Corina; Lee, Geoffrey; Niederlohmann, Eik; Sensenschmidt, Markus; Jacobi, Angela; Bernhardt, Ricardo; Muders, Michael; Rammelt, Stefan; Knaack, Sven; Gelinsky, Michael; Günther, Klaus-Peter; Goodman, Stuart B; Stiehler, Maik

    2016-09-01

    The treatment of critical size bone defects represents a challenge. The growth factor bone morphogenetic protein 2 (BMP-2) is clinically established but has potentially adverse effects when used at high doses. The aim of this study was to evaluate if stromal derived factor-1 alpha (SDF-1α) and BMP-2 released from heparinized mineralized collagen type I matrix (MCM) scaffolds have a cumulative effect on bone regeneration. MCM scaffolds were functionalized with heparin, loaded with BMP-2 and/or SDF-1α and implanted into a murine critical size femoral bone defect (control group, low dose BMP-2 group, low dose BMP-2 + SDF-1α group, and high dose BMP-2 group). After 6 weeks, both the low dose BMP-2 + SDF-1α group (5.8 ± 0.6 mm³, p = 0.0479) and the high dose BMP-2 group (6.5 ± 0.7 mm³, p = 0.008) had a significantly increased regenerated bone volume compared to the control group (4.2 ± 0.5 mm³). There was a higher healing score in the low dose BMP-2 + SDF-1α group (median grade 8; Q1-Q3 7-9; p = 0.0357) than in the low dose BMP-2 group (7; Q1-Q3 5-9) histologically. This study showed that release of BMP-2 and SDF-1α from heparinized MCM scaffolds allows for the reduction of the applied BMP-2 concentration since SDF-1α seems to enhance the osteoinductive potential of BMP-2. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 2126-2134, 2016.

  5. Is Sterile Better Than Aseptic? Comparing the Microbiology of Acellular Dermal Matrices

    PubMed Central

    Klein, Gabriel M.; Nasser, Ahmed E.; Phillips, Brett T.; Gersch, Robert P.; Fourman, Mitchell S.; Lilo, Sarit E.; Fritz, Jason R.; Khan, Sami U.; Dagum, Alexander B.

    2016-01-01

    Introduction: Postoperative infections are a major complication associated with tissue-expander-based breast reconstruction. The use of acellular dermal matrix (ADM) in this surgery has been identified as a potential reservoir of infection, prompting the development of sterile ADM. Although aseptic and sterile ADMs have been investigated, no study has focused on the occurrence and clinical outcome of bacterial colonization before implantation. Methods: Samples of aseptic AlloDerm, sterile Ready-To-Use AlloDerm, and AlloMax were taken before implantation. These samples were incubated in Tryptic soy broth overnight before being streaked on Trypticase soy agar, MacConkey agar, and 5% blood agar plates for culture and incubated for 48 hours. Culture results were cross-referenced with patient outcomes for 1 year postoperatively. Results: A total of 92 samples of ADM were collected from 63 patients. There were 15 cases of postoperative surgical site infection (16.3%). Only 1 sample of ADM (AlloMax) showed growth of Escherichia coli, which was likely a result of contamination. That patient did not develop any infectious sequelae. Patient outcomes showed no difference in the incidence of seroma or infection between sterile and aseptic ADMs. Conclusions: This study evaluates the microbiology of acellular dermal matrices before use in breast reconstruction. No difference was found in the preoperative bacterial load of either aseptic or sterile ADM. No significant difference was noted in infection or seroma formation. Given these results, we believe aseptic processing used on ADMs is equivalent to sterile processing in our patient cohort in terms of clinical infection and seroma occurrence postoperatively. PMID:27482500

  6. Resorbable dome device and guided bone regeneration: an alternative bony defect treatment around implants. A case series.

    PubMed

    Parma-Benfenati, Stefano; Roncati, Marisa; Galletti, Primo; Tinti, Carlo

    2014-01-01

    This case series presents the use of a resorbable "dome device" made of a slow, long-lasting resorbable suturing material to support the barrier creating and maintaining a secluded space to promote bone regeneration. Acellular dermal matrix or cross-linked resorbable collagen membrane, as barriers, combined with mineralized freeze-dried bone allograft, with simultaneous implant placement, were utilized in reconstructing non-space-making defects. Eight implants in six healthy patients were treated with a combination of these resorbable regenerative materials. Only one of seven was treated with a nonsubmerged approach. All sites remained completely covered and no implant exposure occurred during healing. At the 9- to 24-month reentry surgeries, the clinical bone density was equivalent to that of the native bone and the mean number of final exposed threads was 0.5. The mean buccal bone thickness achieved was 3.12 mm, with a mean total coverage of exposed threads in approximately 87.5% of the cases.

  7. Phase II trial of whole-cell pertussis vaccine vs an acellular vaccine containing agglutinogens.

    PubMed

    Miller, E; Ashworth, L A; Robinson, A; Waight, P A; Irons, L I

    1991-01-12

    An acellular pertussis vaccine containing agglutinogens 2 and 3, pertussis toxin, and filamentous haemagglutinin was developed by the Centre for Applied Microbiology and Research in the UK. 188 infants were entered into a randomised blind trial and received either the acellular or a whole-cell vaccine, combined with diphtheria and tetanus toxoids, in a 3, 5, and 8-10 month schedule. Local reactions were similar in the two groups but significantly fewer infants had systemic symptoms after the acellular vaccine. Mean log-antibody titres to the agglutinogen and toxin components were higher with the acellular than with the whole-cell vaccine. Persistence of antibodies one year after the third dose was also better in the acellular group. PMID:1670725

  8. Whooping cough, twenty years from acellular vaccines introduction.

    PubMed

    Greco, D; Esposito, S; Tozzi, A; Pandolfi, E; Icardi, G; Giammanco, A

    2015-01-01

    Clinical pertussis resulting from infection with B. pertussis is a significant medical and public health problem, despite the huge success of vaccination that has greatly reduced its incidence. The whole cell vaccine had an undeniable success over the last 50 years, but its acceptance was strongly inhibited by fear, only partially justified, of severe side effects, but also, in the Western world, by the difficulty to enter in combination with other vaccines: today multi-vaccine formulations are essential to maintain a high vaccination coverage. The advent of acellular vaccines was greeted with enthusiasm by the public health world: in the Nineties, several controlled vaccine trials were carried out: they demonstrated a high safety and good efficacy of new vaccines. In fact, in the Western world, the acellular vaccines completely replaced the whole cells ones. In the last years, ample evidence on the variety of protection of these vaccines linked to the presence of different antigens of Bordetella pertussis was collected. It also became clear that the protection provided, on average around 80%, leaves every year a significant cohort of vaccinated susceptible even in countries with a vaccination coverage of 95%, such as Italy. Finally, it was shown that, as for the pertussis disease, protection decreases over time, to leave a proportion of adolescents and adults unprotected. Waiting for improved pertussis vaccines, the disease control today requires a different strategy that includes a booster at 5 years for infants, but also boosters for teenagers and young adults, re-vaccination of health care personnel, and possibly of pregnant women and of those who are in contact with infants (cocooning). Finally, the quest for better vaccines inevitably tends towards pertussis acellular vaccines with at least three components, which have demonstrated superior effectiveness and have been largely in use in Italy for fifteen years.

  9. Mechanobiology of bone marrow stem cells: from myosin-II forces to compliance of matrix and nucleus in cell forms and fates.

    PubMed

    Shin, Jae-Won; Swift, Joe; Ivanovska, Irena; Spinler, Kyle R; Buxboim, Amnon; Discher, Dennis E

    2013-10-01

    Adult stem cells and progenitors are of great interest for their clinical application as well as their potential to reveal deep sensitivities to microenvironmental factors. The bone marrow is a niche for at least two types of stem cells, and the prototype is the hematopoietic stem cell/progenitors (HSC/Ps), which have saved many thousands of patients for several decades now. In bone marrow, HSC/Ps interact functionally with marrow stromal cells that are often referred to as mesenchymal stem cells (MSCs) or derivatives thereof. Myosin and matrix elasticity greatly affect MSC function, and these mechanobiological factors are now being explored with HSC/Ps both in vitro and in vivo. Also emerging is a role for the nucleus as a mechanically sensitive organelle that is semi-permeable to transcription factors which are modified for nuclear entry by cytoplasmic mechanobiological pathways. Since therapies envisioned with induced pluripotent stem cells and embryonic stem cells generally involve in vitro commitment to an adult stem cell or progenitor, a very deep understanding of stem cell mechanobiology is essential to progress with these multi-potent cells.

  10. [Effect of laminar shear stress on the expression of matrix metalloproteinases-9 in rat bone marrow-derived mesenchymal stem cells].

    PubMed

    Chen, Longju; Sun, Xiaodong; Tang, Jie; Ding, Yan; Li, Jing; Li, Wenchun; Gong, Jian; Wang, Hanqin

    2010-12-01

    This paper was designed to investigate the effect of laminar shear stress on matrix metalloproteinase -9 (MMP-9) expression in rat bone marrow-derived mesenchymal stem cells (MSCs), and the possible signal transduction mechanism involved. Rat bone marrow MSCs were isolated and cultured, then, exposed to laminar shear stress at indicated strengths such as low (5dyne/cm2), medium (15 dyne/cm2) and high (30 dyne/cm2) via parallel plate flow chamber. RT-PCR was used to analyze the expression of MMP-9. The signaling inhibitors such as Wortmannin (PI3K specific inhabitor), SB202190 (p38MAPK specific inhabitor), and PD98059 (ERK1/2 specific inhabitor) were used to investigate the possible mechanical signal transduction pathway. The results showed: (1) The expression of MMP-9 was weak in static state, however, MMP-9 expression increased when MSCs were exposed to 15 dyne/cm2 shear stress for 2 hours, and MMP-9 expression increased with the extension of stimulating time, and it reached the peak at 24 h; (2) MSCs were stimulated by shear stress for 2 hours at different strengths (5 dyne/cm2, 15 dyne/cm2, 30 dyne/cm2), and under all these conditions, the expression of MMP-9 increased, and reached the peak at 15 dyne/cm2; (3) After MSCs were pretreated by three kinds of signal pathway inhibitors, the expression of MMP-9 did not change obviously in Wortmannin group and PD98059 group, but it was significantly inhibited in SB202190 group. This study demonstrated that shear stress could induce the expression of MMP-9 in rat bone marrow-derived mesenchymal stem cells; the amount of MMP-9 expression was closely related to stimulating time and the strengths of shear stress; and p38MAPK signal pathway played a critical role during the process.

  11. Clinical and radiographic evaluation of copolymerized Polylactic/polyglycolic acids as a bone filler in combination with a cellular dermal matrix graft around immediate implants

    PubMed Central

    Soliman, Mahitab M.; Zaki, Azza Abdulrahman; El Gazaerly, Hanaa Mohamed; Shemmrani, Ammar Al; Sorour, Abd El Latif

    2014-01-01

    Objective This study was conducted to evaluate clinically and radiographically the use of a cellular dermal matrix allograft (Alloderm) in combination with PLA/PGA (Fisiograft) around immediate implants. Materials and Methods Fourteen patients were included in this study, three patients received two implants, total of seventeen implants were placed. Periapical radiographs and orthopantomographs were taken. The selected teeth were extracted atraumatically after the reflection of full thickness flaps. One-piece Zimmer implants were placed immediately into the sockets. Weeks from implantation, radiographic evaluation was made at 6 Fisiograft in powder form was placed in the osseous defects around the implants. The implants were immediately restored with provisional crowns free from occlusion. Patients were clinically evaluated at 3, 6, and 14 months after loading which was done after 6 weeks from implantation. Radiographic evaluation was made at 6 and 14 months from implant placement. Results showed that immediate implantation was successful in sixteen out of seventeen implants, clinical parameters regarding plaque index, gingival index, there was a slight decrease through the follow-up periods from 3 to 14 months but it was non-significant, while there was a significant decrease in the probing depth. Radiographically there was a significant increase in the bone density from 6 to 14 months post loading, while the vertical bone defect was significantly decreased. The fisiograft functioned well as space maker and scaffolding material. The Alloderm performed well as a membrane to be used in association with immediate implants and it has a good potentiality for increasing the width of the keratinized gingiva, which is an important feature for implant esthetics. Conclusion the combination technique between the bone graft and the membrane proved to be successful to overcome dehiscence and osseous defects around immediate implants. PMID:25780357

  12. Extracellular Matrix Proteins, Alkaline Phosphatase and Pyrophosphate as Molecular Determinants of Bone, Tooth, Kidney and Vascular Calcification

    NASA Astrophysics Data System (ADS)

    McKee, Marc D.

    2008-09-01

    Progress in biomineralization research in recent years has identified, characterized and described functions for key noncollagenous extracellular matrix proteins regulating crystal growth in the skeleton and dentition. Some of these same proteins expressed in soft tissues undergoing pathologic calcification also inhibit ectopic crystal growth. In addition to extracellular matrix proteins regulating matrix mineralization, the enzyme tissue-nonspecific alkaline phosphatase—which is highly expressed by cells in mineralized tissues—cleaves pyrophosphate, an anionic small-molecule inhibitor of mineralization. Together with the required mineral ion availability necessary for crystal growth, these molecular determinants appear to function in limiting the spread of pathologic calcification seen in soft tissues such as blood vessels and kidneys. Osteopontin, in particular, is a potent calcification inhibitor that accumulates in mineralized tissues and in calcified deposits during vascular calcification and nephrolithiasis/urolithiasis. Additional research is required to establish the exact temporal sequence in which the molecular determinants of pathologic calcification appear relative to mineral crystal growth in different tissues, and to establish their relationship (if any) to the activation of osteogenic differentiation programs.

  13. Preclinical evaluations of acellular biological conduits for peripheral nerve regeneration

    PubMed Central

    Liao, I-Chien; Wan, Hua; Qi, Shijie; Cui, Cunqi; Patel, Paarun; Sun, Wendell

    2013-01-01

    Various types of natural biological conduits have been investigated as alternatives to the current surgical standard approach for peripheral nerve injuries. Autologous nerve graft, the current gold standard for peripheral nerve damage, is limited by clinical challenges such as donor-site morbidity and limited availability. The purpose of this study was to evaluate the efficacy of using acellular xenographic conduits (nerve, artery, and dermis) for the repair of a 1.2 cm critical size defect of peripheral nerve in a rodent model. Four months post surgery, the animal group receiving acellular artery as a nerve conduit showed excellent physiological outcome in terms of the prevention of muscle atrophy and foot ulcer. Histological assessment of the bridged site revealed excellent axon regeneration, as opposed to the nonrepaired control group or the group receiving dermal conduit. Finally, the study evaluated the potential improvement via the addition of undifferentiated mesenchymal stem cells into the artery conduit during the bridging procedure. The mesenchymal stem cell–dosed artery conduit group resulted in significantly higher concentration of regenerated axons over artery conduit alone, and exhibited accelerated muscle atrophy rescue. Our results demonstrated that xenographic artery conduits promoted excellent axonal regeneration with highly promising clinical relevance. PMID:23532671

  14. Acellular dermal matrices in breast reconstructions - a literature review.

    PubMed

    Skovsted Yde, Simon; Brunbjerg, Mette Eline; Damsgaard, Tine Engberg

    2016-08-01

    During the last two decades, acellular dermal matrices (ADM) have been more widely used in reconstructive procedures i.e. breast reconstructions. Several, both synthetic and biologic products derived from human, porcine and bovine tissue, have been introduced. Until this point postoperative complications for the acellular dermal matrices, as a group, have been the main focus. The purpose of this literature review is to summarize the current knowledge on the each biologic product used in breast reconstructions, including product specific complication frequencies. A systematic search of the literature was performed in the PubMed and EMBASE databases, identifying 55 relevant articles, mainly evidence level III. AlloDerm seems to be associated with severe complicating matters in the reconstructive process compared to other products. This could be due to the higher number of investigating studies relative to the others. The surgical area faces certain challenges comparing results, due to surgical variance, the data collection and follow-up. More well-defined guidelines and more high-evidence randomized studies could increase the overall level of evidence in this area. PMID:26881927

  15. The Influence of Autologous Bone Marrow Stem Cell Transplantation on Matrix Metalloproteinases in Patients Treated for Acute ST-Elevation Myocardial Infarction

    PubMed Central

    Furenes, Eline Bredal; Opstad, Trine Baur; Solheim, Svein; Lunde, Ketil; Arnesen, Harald; Seljeflot, Ingebjørg

    2014-01-01

    Background. Matrix metalloproteinase-9 (MMP-9), regulated by tissue inhibitor of metalloproteinase-9 (TIMP-1) and the extracellular matrix metalloproteinase inducer (EMMPRIN), contributes to plaque instability. Autologous stem cells from bone marrow (mBMC) treatment are suggested to reduce myocardial damage; however, limited data exists on the influence of mBMC on MMPs. Aim. We investigated the influence of mBMC on circulating levels of MMP-9, TIMP-1, and EMMPRIN at different time points in patients included in the randomized Autologous Stem-Cell Transplantation in Acute Myocardial Infarction (ASTAMI) trial (n = 100). Gene expression analyses were additionally performed. Results. After 2-3 weeks we observed a more pronounced increase in MMP-9 levels in the mBMC group, compared to controls (P = 0.030), whereas EMMPRIN levels were reduced from baseline to 2-3 weeks and 3 months in both groups (P < 0.0001). Gene expression of both MMP-9 and EMMPRIN was reduced from baseline to 3 months. MMP-9 and EMMPRIN were significantly correlated to myocardial injury (CK: P = 0.005 and P < 0.001, resp.) and infarct size (SPECT: P = 0.018 and P = 0.008, resp.). Conclusion. The results indicate that the regulation of metalloproteinases is important during AMI, however, limited influenced by mBMC. PMID:25294955

  16. Dentin sialophosphoprotein (DSPP) is cleaved into its two natural dentin matrix products by three isoforms of bone morphogenetic protein-1 (BMP1).

    PubMed

    von Marschall, Zofia; Fisher, Larry W

    2010-05-01

    The protease that cleaves the most abundant non-collagenous protein of dentin matrix, dentin sialophosphoprotein (DSPP), into its two final dentin matrix products, dentin sialoprotein (DSP) and dentin phosphoprotein (DPP), has not been directly identified. In this study, full-length recombinant mouse DSPP was made for the first time in furin-deficient mammalian LoVo cells and used to test the ability of three different isoforms of one candidate protease, bone morphogenetic protein-1 (BMP1) to cleave DSPP at the appropriate site. Furthermore, two reported enhancers of BMP1/mTLD activity (procollagen C-endopeptidase enhancer-1, PCPE-1, and secreted frizzled-related protein-2, sFRP2) were tested for their abilities to modulate BMP1-mediated processing of both DSPP and another SIBLING family member with a similar cleavage motif, dentin matrix protein-1 (DMP1). Three splice variants of BMP1 (classic BMP1, the full-length mTolloid (mTLD), and the shorter isoform lacking the CUB3 domain, BMP1-5) were all shown to cleave the recombinant DSPP in vitro although mTLD was relatively inefficient at processing both DSPP and DMP1. Mutation of the MQGDD peptide motif to IEGDD completely eliminated the ability of all three recombinant isoforms to process full-length recombinant DSPP in vitro thereby verifying the single predicted cleavage site. Furthermore when human bone marrow stromal cells (which naturally express furin-activated BMP1) were transduced with the adenovirus-encoding either wild-type or mutant DSPP, they were observed to fully cleave wild-type DSPP but failed to process the mutant DSPP(MQDeltaIE) during biogenesis. All three BMP1 isoforms were shown to process type I procollagen as well as DSPP and DMP1 much more efficiently in low-salt buffer (< or = 50 mM NaCl) compared to commonly used normal saline buffers (150 mM NaCl). Neither PCPE-1 nor sFRP2 were able to enhance any of the three BMP1 isoforms in cleaving either DSPP or DMP1 under either low or normal saline

  17. Odontogenic Differentiation of Human Dental Pulp Stem Cells on Hydrogel Scaffolds Derived from Decellularized Bone Extracellular Matrix and Collagen Type I

    PubMed Central

    White, Lisa J.; Shakesheff, Kevin M.; Tatullo, Marco

    2016-01-01

    Objectives The aim of this study was to evaluate the level of odontogenic differentiation of dental pulp stem cells (DPSCs) on hydrogel scaffolds derived from bone extracellular matrix (bECM) in comparison to those seeded on collagen I (Col-I), one of the main components of dental pulp ECM. Methods DPSCs isolated from human third molars were characterized for surface marker expression and odontogenic potential prior to seeding into bECM or Col-I hydrogel scaffolds. The cells were then seeded onto bECM and Col-I hydrogel scaffolds and cultured under basal conditions or with odontogenic and growth factor (GF) supplements. DPSCs cultivated on tissue culture polystyrene (TCPS) with and without supplements were used as controls. Gene expression of dentin sialophosphoprotein (DSPP), dentin matrix protein 1 (DMP-1) and matrix extracellular phosphoglycoprotein (MEPE) was evaluated by quantitative reverse transcription-polymerase chain reaction (qRT-PCR) and mineral deposition was observed by Von Kossa staining. Results When DPSCs were cultured on bECM hydrogels, the mRNA expression levels of DSPP, DMP-1 and MEPE genes were significantly upregulated with respect to those cultured on Col-I scaffolds or TCPS in the absence of extra odontogenic inducers. In addition, more mineral deposition was observed on bECM hydrogel scaffolds as demonstrated by Von Kossa staining. Moreover, DSPP, DMP-1 and MEPE mRNA expressions of DPSCs cultured on bECM hydrogels were further upregulated by the addition of GFs or osteo/odontogenic medium compared to Col-I treated cells in the same culture conditions. Significance These results demonstrate the potential of the bECM hydrogel scaffolds to stimulate odontogenic differentiation of DPSCs. PMID:26882351

  18. Human Bone-Forming Chondrocytes Cultured in the Hydrodynamic Focusing Bioreactor Retain Matrix Proteins: Similarities to Spaceflight Results

    NASA Technical Reports Server (NTRS)

    Duke, P. J.; Hecht, J.; Montufar-Solis, D.

    2006-01-01

    Fracture healing, crucial to a successful Mars mission, involves formation of a cartilaginous fracture callus which differentiates, mineralizes, ossifies and remodels via the endochondral process. Studies of spaceflown and tailsuspended rats found that, without loading, fracture callus formation and cartilage differentiation within the callus were minimal. We found delayed differentiation of chondrocytes within the rat growth plate on Cosmos 1887, 2044, and Spacelab 3. In the current study, differentiation of human bone-forming chondrocytes cultured in the hydrodynamic focusing bioreactor (HFB) was assessed. Human costochondral chondrocytes in suspension were aggregated overnight, then cultured in the HFB for 25 days. Collagen Type II, aggrecan and unsulfated chondroitin were found extracellularly and chondroitin sulfates 4 and 6 within the cell. Lack of secretion was also found in pancreatic cells of spaceflown rats, and in our SL3 studies. The HFB can be used to study cartilage differentiation in simulated microgravity.

  19. Extracellular bone matrix exhibits hardening elastoplasticity and more than double cortical strength: Evidence from homogeneous compression of non-tapered single micron-sized pillars welded to a rigid substrate.

    PubMed

    Luczynski, Krzysztof W; Steiger-Thirsfeld, Andreas; Bernardi, Johannes; Eberhardsteiner, Josef; Hellmich, Christian

    2015-12-01

    We here report an improved experimental technique for the determination of Young׳s modulus and uniaxial strength of extracellular bone matrix at the single micrometer scale, giving direct access to the (homogeneous) deformation (or strain) states of the tested samples and to the corresponding mechanically recoverable energy, called potential or elastic energy. Therefore, a new protocol for Focused Ion Beam milling of prismatic non-tapered micropillars, and attaching them to a rigid substrate, was developed. Uniaxial strength turns out as at least twice that measured macroscopically, and respective ultimate stresses are preceded by hardening elastoplastic states, already at very low load levels. The unloading portion of quasi-static load-displacement curves revealed Young׳s modulus of 29GPa in bovine extracellular bone matrix. This value is impressively confirmed by the corresponding prediction of a multiscale mechanics model for bone, which has been comprehensively validated at various other observation scales, across tissues from the entire vertebrate animal kingdom.

  20. Gene targeting reveals the role of Oc90 as the essential organizer of the otoconial organic matrix

    PubMed Central

    Zhao, Xing; Yang, Hua; Yamoah, Ebenezer N; Lundberg, Yunxia Wang

    2007-01-01

    A critical part of the functional development of our peripheral balance system is the embryonic formation of otoconia, composite crystals that overlie and provide optimal stimulus input to the sensory epithelium of the gravity receptor in the inner ear. To date neither the functions of otoconial proteins nor the processes of crystal formation are clearly defined. Using gene targeting and protein analysis strategies, we demonstrate that the predominant mammalian otoconin, otoconin-90/95 (Oc90), is essential for formation of the organic matrix of otoconia by specifically recruiting other matrix components, which includes otolin, a novel mammalian otoconin that we identified to be in wildtype murine otoconia. We show that this matrix controls otoconia growth and morphology by embedding the crystallites during seeding and growth. During otoconia development, the organic matrix forms prior to CaCO3 deposition and provides optimal calcification efficiency. Histological and ultrastructural examinations show normal inner ear epithelial morphology but reduced acellular matrices, including otoconial, cupular and tectorial membranes, in Oc90 null mice, likely due to an absence of Oc90 and a profound reduction of otolin. Our data demonstrate the critical roles of otoconins in otoconia seeding, growth and anchoring and suggest mechanistic similarities and differences between otoconia and bone calcification. PMID:17300776

  1. Using genipin-crosslinked acellular porcine corneal stroma for cosmetic corneal lens implants.

    PubMed

    Liu, Zhao; Zhou, Qiang; Zhu, Jixiang; Xiao, Jianhui; Wan, Pengxia; Zhou, Chenjing; Huang, Zheqian; Qiang, Na; Zhang, Wei; Wu, Zheng; Quan, Daping; Wang, Zhichong

    2012-10-01

    Acellular porcine corneal stroma (APCS) has been proven to maintain the matrix microenvironment and is therefore an ideal biomaterial for the repair and reconstruction of corneal stroma. This study aims to develop a method to prepare cosmetic corneal lens implants for leukoma using genipin-crosslinked APCS (Gc-APCS). The Gc-APCS was prepared from APCS immersed in 1.0% genipin aqueous solution (pH 5.5) for 4 h at 37 °C, followed by lyophilization at -10 °C. The color of the Gc-APCS gradually deepened to dark-blue. The degree of crosslinking was 45.7 ± 4.6%, measured by the decrease of basic and hydroxy amino acids. The porous structure and ultrastructure of collagenous lamellae were maintained, and the porosity and BET SSA were 72.7 ± 4.6% and 23.01 ± 3.45 m(2)/g, respectively. The Gc-APCS rehydrated to the physiological water content within 5 min and was highly resistant to collagenase digestion. There were no significant differences in the areal modulus and curvature variation between Gc-APCS and nature porcine cornea. The dark-blue pigments were stable to pH, light and implantation in vivo. Gc-APCS extracts had no inhibitory effects on the proliferation of keratocytes. Corneal neovascularization, graft degradation and corneal rejection were not observed within 6 months.

  2. Acellular Dermal Allograft for Sellar Repair after Transsphenoidal Approach to Pituitary Adenomas

    PubMed Central

    Gaynor, Brandon G.; Benveniste, Ronald J.; Lieberman, Seth; Casiano, Roy; Morcos, Jacques J.

    2013-01-01

    Objectives Our practice has transitioned from using fat autograft to acellular dermal matrix (AlloDerm, LifeCell Corp, Woodlands, Texas, USA). We present the largest series to our knowledge of AlloDerm for sellar floor repair after transsphenoidal approach to pituitary adenoma and compare rates of postoperative cerebrospinal fluid (CSF) leak with an earlier cohort of patients whose CSF leaks were repaired with fat autograft. Design This is a retrospective cohort study comparing sellar repair with fat autograft versus inlay Alloderm between the years 2003 and 2012. The primary end point was postoperative CSF leak. Results A total of 429 patients (368 primary; 83 revision operations) without intraoperative lumbar drainage were included. A total of 18 postoperative CSF leaks were observed (3.9%). Intraoperative CSF leak occurred in 160 cases (35.5%). Among this subset of patients with intraoperative CSF leak, 95 underwent repair with AlloDerm and 46 underwent repair with fat autograft, with postoperative CSF leak rates of 8.4% and 15.2%, respectively (p = 0.34, chi-square test); 19 patients underwent repair with other techniques or no repair at all, with postoperative leak rate of 0%. Conclusions AlloDerm is an effective alternative to fat autograft in cases of low-flow CSF leak following transsphenoidal resection of pituitary adenoma. PMID:24436906

  3. Tissue inhibitor of matrix metalloproteinase-1 suppresses apoptosis of mouse bone marrow stromal cell line MBA-1.

    PubMed

    Guo, L-J; Luo, X-H; Xie, H; Zhou, H-D; Yuan, L-Q; Wang, M; Liao, E-Y

    2006-05-01

    We investigated the action of tissue inhibitor of metalloproteinase-1 (TIMP-1) on apoptosis and differentiation of mouse bone marrow stromal cell line MBA-1. TIMP-1 did not affect alkaline phosphatase (ALP) activity, suggesting that it is not involved in osteoblastic differentiation in MBA-1 cells. However, TIMP-1 inhibited MBA-1 apoptosis induced by serum deprivation in a dose-dependent manner. Our study also showed increased Bcl-2 protein expression and decreased Bax protein expression with TIMP-1 treatment. TIMP-1 decreased cytochrome c release and caspase-3 activation in MBA-1 cells. TIMP-1 activated phosphatidylinositol 3-kinase (PI3-kinase) and c-Jun N-terminal kinase (JNK), and the PI3-kinase inhibitor LY294002 or the JNK inhibitor SP600125 abolished its antiapoptotic activity. To investigate whether antiapoptotic action of TIMP-1 was mediated through its inhibition on MMP activities, we constructed mutant TIMP-1 by side-directed mutagenesis, which abolished the inhibitory activity of MMPs by deletion of Cys1 to Ala4. Wild-type TIMP-1 and mutant TIMP-1 expression plasmids were transfected in MBA-1 cells, and results showed that mutant TIMP-1 still protected the induced MBA-1 cell against apoptosis. These data suggest that TIMP-1 antiapoptotic actions are mediated via the PI3-kinase and JNK signaling pathways and independent of TIMP-1 inhibition of MMP activities.

  4. In vivo bone regeneration using tubular perfusion system bioreactor cultured nanofibrous scaffolds.

    PubMed

    Yeatts, Andrew B; Both, Sanne K; Yang, Wanxun; Alghamdi, Hamdan S; Yang, Fang; Fisher, John P; Jansen, John A

    2014-01-01

    The use of bioreactors for the in vitro culture of constructs for bone tissue engineering has become prevalent as these systems may improve the growth and differentiation of a cultured cell population. Here we utilize a tubular perfusion system (TPS) bioreactor for the in vitro culture of human mesenchymal stem cells (hMSCs) and implant the cultured constructs into rat femoral condyle defects. Using nanofibrous electrospun poly(lactic-co-glycolic acid)/poly(ε-caprolactone) scaffolds, hMSCs were cultured for 10 days in vitro in the TPS bioreactor with cellular and acellular scaffolds cultured statically for 10 days as a control. After 3 and 6 weeks of in vivo culture, explants were removed and subjected to histomorphometric analysis. Results indicated more rapid bone regeneration in defects implanted with bioreactor cultured scaffolds with a new bone area of 1.23 ± 0.35 mm(2) at 21 days compared to 0.99 ± 0.43 mm(2) and 0.50 ± 0.29 mm(2) in defects implanted with statically cultured scaffolds and acellular scaffolds, respectively. At the 21 day timepoint, statistical differences (p<0.05) were only observed between defects implanted with cell containing scaffolds and the acellular control. After 42 days, however, defects implanted with TPS cultured scaffolds had the greatest new bone area with 1.72 ± 0.40 mm(2). Defects implanted with statically cultured and acellular scaffolds had a new bone area of 1.26 ± 0.43 mm(2) and 1.19 ± 0.33 mm(2), respectively. The increase in bone growth observed in defects implanted with TPS cultured scaffolds was statistically significant (p<0.05) when compared to both the static and acellular groups at this timepoint. This study demonstrates the efficacy of the TPS bioreactor to improve bone tissue regeneration and highlights the benefits of utilizing perfusion bioreactor systems to culture MSCs for bone tissue engineering.

  5. Use of an acellular flowable dermal replacement scaffold on lower extremity sinus tract wounds: a retrospective series.

    PubMed

    Brigido, Stephen A; Schwartz, Edward; McCarroll, Raymond; Hardin-Young, Janet

    2009-04-01

    A novel injectable human dermal matrix has been developed for the treatment of complex diabetic sinus tract wounds. Bioengineered grafts are commercially available that have been somewhat effective in treating chronic wounds such as diabetic foot ulcers; however, these bioengineered grafts are only available in sheet form. These therapies are less effective in treating complex or irregularly shaped wounds that demonstrate tunnels or extensions into deep soft tissue. One acellular graft (GRAFTJACKET, Matrix, Wright Medical Technology, Arlington, Tennessee) that has been shown to effectively treat open wounds is also available in a micronized form (GRAFTJACKET Xpress Scaffold, Wright Medical Technology). This human dermal graft forms a flowable soft tissue scaffold that can be delivered via syringe into tunneling wounds. In this retrospective series, 12 patients with deep tunneling wounds were treated with GRAFTJACKET Xpress Scaffold and followed for 12 weeks. Complete wound healing was achieved in 10 of 12 patients within the 12-week evaluation. The average time to complete healing was 8.5 weeks, whereas the average time to depth healing was 7.8 weeks. The data from the study suggest that this injectable human dermal matrix has unique properties that allow it to facilitate healing of complex tunneling diabetic foot ulcers. The material is easy to prepare and inject into the wound, thereby preventing the necessity of extensive surgical exposure. The matrix supports neo-subcutaneous tissue formation and allows the body to rapidly repair these wounds.

  6. Extended Eden model reproduces growth of an acellular slime mold

    NASA Astrophysics Data System (ADS)

    Wagner, Geri; Halvorsrud, Ragnhild; Meakin, Paul

    1999-11-01

    A stochastic growth model was used to simulate the growth of the acellular slime mold Physarum polycephalum on substrates where the nutrients were confined in separate drops. Growth of Physarum on such substrates was previously studied experimentally and found to produce a range of different growth patterns [Phys. Rev. E 57, 941 (1998)]. The model represented the aging of cluster sites and differed from the original Eden model in that the occupation probability of perimeter sites depended on the time of occupation of adjacent cluster sites. This feature led to a bias in the selection of growth directions. A moderate degree of persistence was found to be crucial to reproduce the biological growth patterns under various conditions. Persistence in growth combined quick propagation in heterogeneous environments with a high probability of locating sources of nutrients.

  7. Boron Induces Early Matrix Mineralization via Calcium Deposition and Elevation of Alkaline Phosphatase Activity in Differentiated Rat Bone Marrow Mesenchymal Stem Cells

    PubMed Central

    Movahedi Najafabadi, Bent-al-hoda; Abnosi, Mohammad Hussein

    2016-01-01

    Objective Boron (B) is essential for plant development and might be an essential micronutrient for animals and humans. This study was conducted to characterize the impact of boric acid (BA) on the cellular and molecular nature of differentiated rat bone marrow mesenchymal stem cells (BMSCs). Materials and Methods In this experimental study, BMSCs were extracted and expanded to the 3rdpassage, then cultured in Dulbecco’s Modified Eagle’s Medium (DMEM) complemented with osteogenic media as well as 6 ng/ml and 6 µg/ml of BA. After 5, 10, 15 and 21 days the viability and the level of mineralization was determined using MTT assay and alizarin red respectively. In addition, the morphology, nuclear diameter and cytoplasmic area of the cells were studied with the help of fluorescent dye. The concentration of calcium, activity of alanine transaminase (ALT), aspartate transaminase (AST), lactate dehydrogenase (LDH) and alkaline phosphatase (ALP) as well as sodium and potassium levels were also evaluated using commercial kits and a flame photometer respectively. Results Although 6 µg/ml of BA was found to be toxic, a concentration of 6 ng/ml increased the osteogenic ability of the cell significantly throughout the treatment. In addition it was observed that B treatment caused the early induction of matrix mineralization compared to controls. Conclusion Although more investigation is required, we suggest the prescription of a very low concentration of B in the form of BA or foods containing BA, in groups at high risk of osteoporosis or in the case of bone fracture. PMID:27054120

  8. Protection against pertussis by Takeda's acellular pertussis vaccine: household contact studies in Kawasaki City, Japan.

    PubMed

    Kato, T; Kaku, H; Arimoto, Y

    1988-01-01

    To evaluate the vaccine efficacy of an acellular pertussis vaccine which has been in clinical use in Japan since 1981, a retrospective study was performed by a questionnaire survey of secondary pertussis attacks through family contact in 146 children with pertussis diagnosed in the period from January 1981 through May 1988. In this study, Takeda's acellular vaccine which contains a high level of FHA, low level of PT and a small amount of agglutinogen, was evaluated. Secondary pertussis attacks through family contact were found in 17 of 27 siblings (62.9%) not immunized with pertussis vaccine. On the other hand, 26 siblings immunized with Takeda's acellular vaccine were exposed to pertussis through family contact and a secondary attack was seen in only one of them (3.8%). The present study revealed an efficacy rate of 93.9% for Takeda's acellular pertussis vaccine. PMID:3078808

  9. Protection against pertussis by acellular pertussis vaccines (Takeda, Japan): household contact studies in Kawasaki City, Japan.

    PubMed

    Kato, T; Goshima, T; Nakajima, N; Kaku, H; Arimoto, Y; Hayashi, F

    1989-12-01

    To evaluate the vaccine efficacy of an acellular pertussis vaccine which has been in clinical use in Japan since 1981, a retrospective study was performed by a questionnaire survey of secondary pertussis attacks through family contact in 146 children with pertussis diagnosed in the period from January 1981 through May 1988. In this study, acellular vaccine made by Takeda Pharmaceutical Company, which contains a high level of FHA (filamentous hemagglutinin), a low level of PT (pertussis toxin) and a small amount of agglutinogen, was evaluated. Secondary pertussis attacks through family contact were found in 17 of 29 siblings (58.6%) not immunized with pertussis vaccine. On the other hand, 27 siblings immunized with Takeda's acellular vaccine were exposed to pertussis through family contact and a secondary attack was seen in only one of them (3.7%). The present study revealed an efficacy rate of 93.7% for Takeda's acellular pertussis vaccine. PMID:2516396

  10. [Protection against pertussis by Japanese T type acellular pertussis vaccine: household contact study in Kawasaki City].

    PubMed

    Kato, T; Matsuyoshi, S; Goshima, T; Nakajima, N; Yamamoto, H; Arimoto, Y; Kaku, H; Hayashi, F

    1989-09-01

    To evaluate the vaccine efficacy of acellular pertussis vaccine which has been in clinical use in Japan since 1981, a retrospective study was made by a questionnaire from secondary pertussis attack through family contact in 149 children with pertussis diagnosed in the period from January 1981 through May 1988. In this study, Takeda's acellular vaccine which contains a high level of FHA, low level of PT and a small amount of agglutinogen, was evaluated. Secondary pertussis attacks through family contact were found in 17 of 29 siblings (58.6%) not immunized with pertussis vaccine. On the other hand of the siblings immunized with Takeda's acellular vaccine 27 were exposed to pertussis through family contact and a secondary attack was seen in only one of them (3.4%). The present study revealed an efficacy rate of 94.2% for the Takeda's acellular pertussis vaccine. PMID:2509597

  11. mRNA expression and protein localization of dentin matrix protein 1 during dental root formation.

    PubMed

    Toyosawa, S; Okabayashi, K; Komori, T; Ijuhin, N

    2004-01-01

    Dentin matrix protein 1 (DMP1) is an acidic phosphoprotein. DMP1 was initially detected in dentin and later in other mineralized tissues including cementum and bone, but the DMP1 expression pattern in tooth is still controversial. To determine the precise localization of DMP1 messenger RNA (mRNA) and the protein in the tooth, we performed in situ hybridization and immunohistochemical analyses using rat molars and incisors during various stages of root formation. During root dentin formation of molars, DMP1 mRNA was detected in root odontoblasts in parallel with mineralization of the dentin. However, the level of DMP1 mRNA expression in root odontoblasts decreased near the coronal part and was absent in coronal odontoblasts. DMP1 protein was localized along dentinal tubules and their branches in mineralized root dentin, and the distribution of DMP1 shifted from the end of dentinal tubules to the base of the tubules as dentin formation progressed. During the formation of the acellular cementum, DMP1 mRNA was detected in cementoblasts lining the acellular cementum where its protein was localized. During the formation of the cellular cementum, DMP1 mRNA was detected in cementocytes embedded in the cellular cementum but not in cementoblasts, and its protein was localized in the pericellular cementum of cementocytes including their processes. During dentin formation of incisors, DMP1 mRNA was detected in odontoblasts on the cementum-related dentin, where its protein was localized along dentinal tubules near the mineralization front. The localization of DMP1 mRNA and protein in dentin and cementum was related to their mineralization, suggesting that one of the functions of DMP1 may be involved in the mineralization of dentin and cementum during root formation. PMID:14751569

  12. [Actin cytoskeleton organization and spreading of bone marrow stromal cells and cartilage cells during their combined and independent cultivation on different extracellular matrix proteins].

    PubMed

    Sakhenberg, E I; Nikolaenko, N S; Pinaev, G P

    2014-01-01

    To clarify the mutual influence of bone marrow stromal cells (BMSCs) and cartilage cells we studied the organization of their actin cytoskeleton and cell spreading on different extracellular matrix proteins--laminin 2/4, collagen type I or fibronectin. It has been shown that the most pronounced difference in morphological characteristics of the cells such as their form, size and actin cytoskeleton organization occur in the case of interaction with fibronectin. So, after separate brief incubation of both cell types on fibronectin, the average area of BMSCs spreading was about 4 times greater than the area of the cartilage cell spreading. However, in the co-culture of these cells in a ratio of 1:1, the average jointed spreading area on fibronctin was nearly 1.5 times less than the theoretically calculated. To determine the nature of exposure of the cells to each other we have studied spreading of these cells in the media conditioned by another cell type. We have found that the area of BMSC's spreading in the medium conditioned by cartilage cells is markedly smaller than the area of spreading of the same cells in the control medium. These data suggest that the cartilage cells secrete factors that reduce BMSC's spreading.

  13. Differences in matrix composition between calvaria and long bone in mice suggest differences in biomechanical properties and resorption: Special emphasis on collagen.

    PubMed

    van den Bos, T; Speijer, D; Bank, R A; Brömme, D; Everts, V

    2008-09-01

    The mammalian skeleton consists of bones that are formed in two different ways: long bones via endochondral ossification and flat bones via intramembranous ossification. These different formation modes may result in differences in the composition of the two bone types. Using the 2D-difference in gel electrophoresis technique and mass spectrometry, we analyzed the composition of murine mineral-associated proteins of calvaria and long bone. Considerable differences in protein composition were observed. Flat bones (calvariae) contained more soluble collagen (8x), pigment epithelium derived factor (3x) and osteoglycin (4x); whereas long bones expressed more chondrocalcin (3x), thrombospondin- 1 (4x), fetuin (4x), secreted phosphoprotein 24 (3x), and thrombin (7x). Although cystatin motifs containing proteins, such as secreted phosphoprotein 24 and fetuin are highly expressed in long bone, they did not inhibit the activity of the cysteine proteinases cathepsin B and K. The solubility of collagen differed which coincided with differences in collagen crosslinking, long bone containing 3x more (hydroxylysine)-pyridinoline. The degradation of long bone collagen by MMP2 (but not by cathepsin K) was impaired. These differences in collagen crosslinking may explain the differences in the proteolytic pathways osteoclasts use to degrade bone. Our data demonstrate considerable differences in protein composition of flat and long bones and strongly suggest functional differences in formation, resorption, and mechanical properties of these bone types. PMID:18583211

  14. True MRI assessment of stem cell chondrogenesis in a tissue engineered matrix.

    PubMed

    Pothirajan, Padmabharathi; Dorcemus, Deborah; Nukavarapu, Syam; Kotecha, Mrignayani

    2014-01-01

    Developing a non-invasive method to monitor the growth of tissue-engineered cartilage is of utmost importance for tracking the progress and predicting the success or failure of tissue-engineering approaches. Magnetic Resonance Imaging (MRI) is a leading non-invasive technique suitable for follow-through in preclinical and clinical stages. As complex tissue-engineering approaches are being developed for cartilage tissue engineering, it is important to develop strategies for true non-invasive MRI monitoring that can take into account contributions of the scaffold, cells and extracellular matrix (ECM) using MR parameters. In the current study, we present the preliminary MRI assessment of chondrogenic differentiation of human bone marrow derived stem cells seeded onto a specially designed osteochondral matrix system. We performed water relaxation times (T1 and T2) MRI measurements at 7, 14 and 28 days after cell seeding. The MRI experiments were performed for the tissue-engineered cartilage as well as for acellular scaffolds. We identified that the contribution of the scaffold is the dominant contribution in MR parameters of engineered cartilage and that it hinders observation of the tissue growth. An attempt is made to filter out this contribution, for the first time, in order to make a true observation of tissue growth using MRI. PMID:25570852

  15. A comparative study of the proliferation and osteogenic differentiation of human periodontal ligament cells cultured on β-TCP ceramics and demineralized bone matrix with or without osteogenic inducers in vitro.

    PubMed

    An, Shaofeng; Gao, Yan; Huang, Xiangya; Ling, Junqi; Liu, Zhaohui; Xiao, Yin

    2015-05-01

    The repair of bone defects that result from periodontal diseases remains a clinical challenge for periodontal therapy. β-tricalcium phosphate (β-TCP) ceramics are biodegradable inorganic bone substitutes with inorganic components that are similar to those of bone. Demineralized bone matrix (DBM) is an acid-extracted organic matrix derived from bone sources that consists of the collagen and matrix proteins of bone. A few studies have documented the effects of DBM on the proliferation and osteogenic differentiation of human periodontal ligament cells (hPDLCs). The aim of the present study was to investigate the effects of inorganic and organic elements of bone on the proliferation and osteogenic differentiation of hPDLCs using three-dimensional porous β-TCP ceramics and DBM with or without osteogenic inducers. Primary hPDLCs were isolated from human periodontal ligaments. The proliferation of the hPDLCs on the scaffolds in the growth culture medium was examined using a Cell-Counting kit-8 (CCK-8) and scanning electron microscopy (SEM). Alkaline phosphatase (ALP) activity and the osteogenic differentiation of the hPDLCs cultured on the β-TCP ceramics and DBM were examined in both the growth culture medium and osteogenic culture medium. Specific osteogenic differentiation markers were examined using reverse transcription-quantitative polymerase chain reaction (RT-qPCR). SEM images revealed that the cells on the β-TCP were spindle-shaped and much more spread out compared with the cells on the DBM surfaces. There were no significant differences observed in cell proliferation between the β-TCP ceramics and the DBM scaffolds. Compared with the cells that were cultured on β-TCP ceramics, the ALP activity, as well as the Runx2 and osteocalcin (OCN) mRNA levels in the hPDLCs cultured on DBM were significantly enhanced both in the growth culture medium and the osteogenic culture medium. The organic elements of bone may exhibit greater osteogenic differentiation effects

  16. Investigation of the regenerative capacity of an acellular porcine medial meniscus for tissue engineering applications.

    PubMed

    Stapleton, Thomas W; Ingram, Joanne; Fisher, John; Ingham, Eileen

    2011-01-01

    Previously, we have described the development of an acellular porcine meniscal scaffold. The aims of this study were to determine the immunocompatibility of the scaffold and capacity for cellular attachment and infiltration to gain insight into its potential for meniscal repair and replacement. Porcine menisci were decellularized by exposing the tissue to freeze-thaw cycles, incubation in hypotonic tris buffer, 0.1% (w/v) sodium dodecyl sulfate in hypotonic buffer plus protease inhibitors, nucleases, hypertonic buffer followed by disinfection using 0.1% (v/v) peracetic, and final washing in phosphate-buffered saline. In vivo immunocompatibility was assessed after implantation of the acellular meniscal scaffold subcutaneously into galactosyltransferase knockout mice for 3 months in comparison to fresh and acellular tissue treated with α-galactosidase (negative control). The cellular infiltrates in the explants were assessed by histology and characterized using monoclonal antibodies against: CD3, CD4, CD34, F4/80, and C3c. Static culture was used to assess the potential of acellular porcine meniscal scaffold to support the attachment and infiltration of primary human dermal fibroblasts and primary porcine meniscal cells in vitro. The explants were surrounded by capsules that were more pronounced for the fresh meniscal tissue compared to the acellular tissues. Cellular infiltrates compromised mononuclear phagocytes, CD34-positive cells, and nonlabeled fibroblastic cells. T-lymphocytes were sparse in all explanted tissue types and there was no evidence of C3c deposition. The analysis revealed an absence of a specific immune response to all of the implanted tissues. Acellular porcine meniscus was shown to be capable of supporting the attachment and infiltration of primary human fibroblasts and primary porcine meniscal cells. In conclusion, acellular porcine meniscal tissue exhibits excellent immunocompatibility and potential for cellular regeneration in the longer term.

  17. Effect of Androgen Blockade on HER-2 and Matrix Metalloproteinase-2 Expression on Bone Marrow Micrometastasis and Stromal Cells in Men with Prostate Cancer

    PubMed Central

    Murray, N. P.; Reyes, E.; Badinez, L.; Orellana, N.; Fuentealba, C.; Olivares, R.; Porcell, J.; Dueñas, R.

    2013-01-01

    Introduction. HER-2 has been associated with castrate resistant prostate cancer and matrix metalloproteinase-2 (MMP-2) in the dissemination and invasion of tumor cells as well as activating angiogenesis. We present an immunocytochemical study of the effect of androgen blockade on the expression of HER-2 and MMP-2 in bone marrow micrometastasis and the surrounding stromal cells in men with prostate cancer. Methods and Patients. A cross-sectional study of men with prostate cancer. Touch preps were obtained from bone marrow biopsies of men with prostate cancer, before and after radical prostatectomy and during androgen blockade. Micrometastasis detected with anti-PSA immunocytochemistry underwent processing with anti-HER-2 and anti-MMP-2 immunocytochemistry. Patients were defined as HER-2 positive or negative, MMP-2 negative or an MMP-2 pattern described as border or central and stromal MMP-2 defined as positive or negative. The expression of the biomarkers was compared before and after primary treatment and during androgen blockade in relation to the serum PSA at the time of sampling and duration of androgen blockade. Results. 191 men participated, 35 men before surgery and 43 after surgery; there were no significant differences in HER-2 expression between groups, there was no MMP-2 expression centrally or stromal expression of MMP-2. In men with androgen blockade, HER-2 expression was significantly higher; there was a trend for increasing HER-2 expression up to 5 years; central MMP-2 expression significantly increased after 3 years, while stromal MMP-2 significantly increased after 6 years. MMP-2 expression both in micrometastasis and stroma was significantly associated with HER-2 expression. Expression of MMP-2 at the border of the micrometastasis was not associated with HER-2 expression and occurred in the absence of androgen blockade. Conclusions. Androgen blockade decreases serum PSA by eliminating HER-2 negative prostate cancer cells. However, there is early

  18. [Clinical nuclear medicine in bone metastases].

    PubMed

    Kawabe, Joji; Higashiyama, Shigeaki; Shiomi, Susumu

    2013-03-01

    (99m)Tc-hydroxymethylene diphosphonate is not directly to Calcium of the bone matrix, but is binding to hydroxyapatite within the bone matrix. Strontium-89 is a member of family II A of the periodic table, same as Calcium, and is incorporated into bone matrix directly. It is very important that the the regions of the pain from bone metastases are present in the site of the abnormal uptake by bone metastases. PMID:23445892

  19. Xeno-free culture condition for human bone marrow and umbilical cord matrix-derived mesenchymal stem/stromal cells using human umbilical cord blood serum

    PubMed Central

    Esmaeli, Azadeh; Moshrefi, Mojgan; Shamsara, Ali; Eftekhar-vaghefi, Seyed Hasan; Nematollahi-mahani, Seyed Noureddin

    2016-01-01

    Background: Fetal bovine serum (FBS) is widely used in cell culture laboratories, risk of zoonotic infections and allergic side effects create obstacles for its use in clinical trials. Therefore, an alternative supplement with proper inherent growth-promoting activities is demanded. Objective: To find FBS substitute, we tested human umbilical cord blood serum (hUCS) for proliferation of human umbilical cord matrix derived mesenchymal stem cells (hUC-MSCs) and human bone marrow-derived mesenchymal cells (hBM-MSCs). Materials and Methods: Umbilical cord blood of healthy neonates, delivered by Caesarian section, was collected and the serum was separated. hUC-MSCs and hBM-MSCs were isolated and characterized by assessment of cell surface antigens by flow cytometry, alkaline phosphatase activity and osteogenic/adipogenic differentiation potential. The cells were then cultured in Iscove's Modified Dulbecco's Medium (IMDM) by conventional methods in three preparations: 1- with hUCS, 2- with FBS, and 3- without serum supplements. Cell proliferation was measured using WST-1 assay, and cell viability was assessed by trypan blue staining. Results: The cells cultured in hUCS and FBS exhibited similar morphology and mesenchymal stem cells properties. WST-1 proliferation assay data showed no significant difference between the proliferation rate of either cells following hUCS and FBS supplementation. Trypan blue exclusion dye test also revealed no significant difference for viability between hUCS and FBS groups. A significant difference was detected between the proliferation rate of stem cells cultured in serum-supplemented medium compared with serum-free medium. Conclusion: Our results indicate that human umbilical cord serum can effectively support proliferation of hBM-MSCS and hUC-MSCs in vitro and can be used as an appropriate substitute for FBS, especially in clinical studies. PMID:27738658

  20. Low melting point amphiphilic microspheres for delivery of bone morphogenetic protein-6 and transforming growth factor-β3 in a hydrogel matrix.

    PubMed

    Sukarto, Abby; Amsden, Brian G

    2012-02-28

    Low melting-point poly(1,3-trimethylene carbonate-co-ε-caprolactone)-b-poly(ethylene glycol)-b-poly(1,3-trimethylene carbonate-co-ε-caprolactone), P(TMC-CL)(2)-PEG, was employed to fabricate microspheres for sustained growth factor delivery in a photocrosslinked N-methacrylate glycol chitosan hydrogel matrix. The P(TMC-CL)(2)-PEG had a melting range such that it was solid at 10°C, yet liquid with a low degree of crystallinity at 37°C. The in vitro degradation of P(TMC-CL)(2)-PEG microspheres was slow, regardless of the triblock copolymer molecular weight and so did not influence protein release. The size of protein loaded P(TMC-CL)(2)-PEG microspheres manufactured using a low-temperature electrospray technique was between 65 and 85μm. Initial formulation work was done with the model protein lysozyme, co-lyophilized with trehalose and encapsulated as approximately 2μm particles within P(TMC-CL)(2)-PEG microspheres. This work indicated a sustained release could be achieved with high trehalose content (90% w/w) in the particles. Under these conditions, the release rate of bone morphogenetic protein-6 was more sustained than that of the excipient bovine serum albumin (BSA) and closely followed that of lysozyme. On the other hand, transforming growth factor-β3 and the stabilizing agent BSA generated similar release profiles. This difference in release was proposed to be linked to the protein isoelectric point, with positively charged proteins possibly being more strongly adsorbed to the P(TMC-CL)(2)-PEG. Both growth factors were released in highly bioactive form, indicating the potential of the release approach. PMID:22037107

  1. Comparative biological activities of acellular pertussis vaccines produced by Kitasato.

    PubMed

    Watanabe, M; Izumiya, K; Sato, T; Yoshino, K; Nakagawa, N; Ohoishi, M; Hoshino, M

    1991-04-01

    The quality of 14 lots of acellular pertussis-diphtheria-tetanus (AC-PDT) vaccines manufactured by the Kitasato Institute during the period 1987-1990 were investigated. The geometric means of HSU, LPU, and BWDU were 0.078, 0.257, and 7.33 per ml respectively. The potency was higher than 14 IU per ml. These results indicated the consistency of the Kitasato AC-PDT vaccines. The antibody response to the AC-PDT vaccines was measured in primary and secondary vaccinated mice by ELISA. IgG antibody response to FHA and PT was obtained in all immunized mice (P less than 0.001) after the primary injection. In contrast, IgG antibody response to fimbriae 2 showed a significant titer rise (P less than 0.001) after the booster injection. The results indicated that the Kitasato AC-P vaccines consisted of protein, PT and FHA as the major antigens, and a little agglutinogen as the minor antigen. PMID:1798236

  2. Characterization of co-purified acellular pertussis vaccines.

    PubMed

    Xu, Yinghua; Tan, Yajun; Asokanathan, Catpagavalli; Zhang, Shumin; Xing, Dorothy; Wang, Junzhi

    2015-01-01

    Whole-cell pertussis vaccines (WPVs) have been completely replaced by the co-purified acellular vaccines (APVs) in China. To date few laboratory studies were reported for co-purified APVs in terms of their antigenic composition and protective immune responses. To further understand the antigenic composition in co-purified APVs, in the present study 2-dimensional gel electrophoresis-based proteomic technology was used to analyze the composition of co-purified APVs. The results showed that besides the main antigens pertussis toxin (PT) and filamentous hemagglutinin (FHA), co-purified APVs also contained pertactin (PRN), fimbriae (FIM) 2and3 and other minor protein antigens. Of the 9 proteins identified, 3 were differentially presented in products from manufacturer 1 and manufacturer 2. Compared with WPVs and purified APVs, co-purified APVs induced a mixed Th1/Th2 immune response with more toward to a Th1 response than the purified APVs in this study. These results hint that different immune mechanisms might be involved in protection induced by co-purified and purified APVs.

  3. Characterization of co-purified acellular pertussis vaccines

    PubMed Central

    Xu, Yinghua; Tan, Yajun; Asokanathan, Catpagavalli; Zhang, Shumin; Xing, Dorothy; Wang, Junzhi

    2015-01-01

    Whole-cell pertussis vaccines (WPVs) have been completely replaced by the co-purified acellular vaccines (APVs) in China. To date few laboratory studies were reported for co-purified APVs in terms of their antigenic composition and protective immune responses. To further understand the antigenic composition in co-purified APVs, in the present study 2-dimensional gel electrophoresis-based proteomic technology was used to analyze the composition of co-purified APVs. The results showed that besides the main antigens pertussis toxin (PT) and filamentous hemagglutinin (FHA), co-purified APVs also contained pertactin (PRN), fimbriae (FIM) 2and3 and other minor protein antigens. Of the 9 proteins identified, 3 were differentially presented in products from manufacturer 1 and manufacturer 2. Compared with WPVs and purified APVs, co-purified APVs induced a mixed Th1/Th2 immune response with more toward to a Th1 response than the purified APVs in this study. These results hint that different immune mechanisms might be involved in protection induced by co-purified and purified APVs. PMID:25610957

  4. A Complication Analysis of 2 Acellular Dermal Matrices in Prosthetic-based Breast Reconstruction

    PubMed Central

    Page, Eugenia K.; Hart, Alexandra; Rudderman, Randall; Carlson, Grant W.; Losken, Albert

    2016-01-01

    Background: Acellular dermal matrices (ADM) are now routine in postmastectomy prosthetic-based breast reconstruction. The goal of the current study was to compare the complications of 2 ADM products—AlloDerm and Cortiva. Methods: A retrospective analysis of prosthetic-based breast reconstruction in Atlanta, Ga., over 5 years. Inclusion criteria were the use of the ADM types (AlloDerm or Cortiva) and use of a tissue expander or implant. Statistical analysis compared group demographics, risk factors, and early complications. Results: Of the 298 breast reconstructions, 174 (58.4%) used AlloDerm and 124 (41.6%) used Cortiva. There was no difference in overall complication frequency (16 AlloDerm and 18 Cortiva; P = 0.195). Within specific categories, there was a difference in mastectomy skin flap necrosis, but, based on further regression analysis, this was attributable to differences in body mass index (P = 0.036). Furthermore, there were no differences in the rates of infection (6 AlloDerm and 5 Cortiva; P = 1.0), seroma/hematoma (9 AlloDerm and 7 Cortiva; P = 1.0), or drain duration (13.2 day AlloDerm and 14.2 day Cortiva, P = 0.2). By using a general estimating equation for binomial logistical regression, it was found that only current tobacco use (P = 0.033) was a significant predictor for a complication. Trending predictors were body mass index (P = 0.074) and age (P = 0.093). The type of matrix was not a significant predictor for any of the recorded complication (P = 0.160). Conclusions: Although AlloDerm is well established, we have shown that Cortiva has an equivalent complication frequency. Future work will focus on long-term outcome measures and histological evaluation of vascularization and integration. PMID:27536479

  5. Direct Hospital Cost of Outcome Pathways in Implant-Based Reconstruction with Acellular Dermal Matrices

    PubMed Central

    Qureshi, Ali A.; Broderick, Kristen; Funk, Susan; Reaven, Nancy; Tenenbaum, Marissa M.

    2016-01-01

    Background: Current cost data on tissue expansion followed by exchange for permanent implant (TE/I) reconstruction lack a necessary assessment of the experience of a heterogenous breast cancer patient population and their multiple outcome pathways. We extend our previous analysis to that of direct hospital cost as bundling of payments is likely to follow the changing centralization of cancer care at the hospital level. Methods: We performed a retrospective analysis (2003–2009) of TE/I reconstructions with or without an acellular dermal matrix (ADM), namely Alloderm RTM. Postreconstructive events were analyzed and organized into outcome pathways as previously described. Aggregated and normalized inpatient and outpatient hospital direct costs and physician reimbursement were generated for each outcome pathway with or without ADM. Results: Three hundred sixty-seven patients were analyzed. The average 2-year hospital direct cost per TE/I breast reconstruction patient was $11,862 in the +ADM and $12,319 in the −ADM groups (P > 0.05). Initial reconstructions were costlier in the +ADM ($6,868) than in the −ADM ($5,615) group, but the average cost of subsequent postreconstructive events within 2 years was significantly lower in +ADM ($5,176) than −ADM ($6,704) patients (P < 0.05). When a complication occurred, but reconstruction was still completed within 2 years, greater costs were incurred in the −ADM than in the +ADM group for most scenarios, leading to a net equalization of cost between study groups. Conclusion: Although direct hospital cost is an important factor for resource and fund allocation, it should not remain the sole factor when deciding to use ADM in TE/I reconstruction.

  6. Direct Hospital Cost of Outcome Pathways in Implant-Based Reconstruction with Acellular Dermal Matrices

    PubMed Central

    Qureshi, Ali A.; Broderick, Kristen; Funk, Susan; Reaven, Nancy; Tenenbaum, Marissa M.

    2016-01-01

    Background: Current cost data on tissue expansion followed by exchange for permanent implant (TE/I) reconstruction lack a necessary assessment of the experience of a heterogenous breast cancer patient population and their multiple outcome pathways. We extend our previous analysis to that of direct hospital cost as bundling of payments is likely to follow the changing centralization of cancer care at the hospital level. Methods: We performed a retrospective analysis (2003–2009) of TE/I reconstructions with or without an acellular dermal matrix (ADM), namely Alloderm RTM. Postreconstructive events were analyzed and organized into outcome pathways as previously described. Aggregated and normalized inpatient and outpatient hospital direct costs and physician reimbursement were generated for each outcome pathway with or without ADM. Results: Three hundred sixty-seven patients were analyzed. The average 2-year hospital direct cost per TE/I breast reconstruction patient was $11,862 in the +ADM and $12,319 in the −ADM groups (P > 0.05). Initial reconstructions were costlier in the +ADM ($6,868) than in the −ADM ($5,615) group, but the average cost of subsequent postreconstructive events within 2 years was significantly lower in +ADM ($5,176) than −ADM ($6,704) patients (P < 0.05). When a complication occurred, but reconstruction was still completed within 2 years, greater costs were incurred in the −ADM than in the +ADM group for most scenarios, leading to a net equalization of cost between study groups. Conclusion: Although direct hospital cost is an important factor for resource and fund allocation, it should not remain the sole factor when deciding to use ADM in TE/I reconstruction. PMID:27622099

  7. A comparative study of the effects of different bioactive fillers in PLGA matrix composites and their suitability as bone substitute materials: A thermo-mechanical and in vitro investigation.

    PubMed

    Simpson, R L; Nazhat, S N; Blaker, J J; Bismarck, A; Hill, R; Boccaccini, A R; Hansen, U N; Amis, A A

    2015-10-01

    Bone substitute composite materials with poly(L-lactide-co-glycolide) (PLGA) matrices and four different bioactive fillers: CaCO3, hydroxyapatite (HA), 45S5 Bioglass(®) (45S5 BG), and ICIE4 bioactive glass (a lower sodium glass than 45S5 BG) were produced via melt blending, extrusion and moulding. The viscoelastic, mechanical and thermal properties, and the molecular weight of the matrix were measured. Thermogravimetric analysis evaluated the effect of filler composition on the thermal degradation of the matrix. Bioactive glasses caused premature degradation of the matrix during processing, whereas CaCO3 or HA did not. All composites, except those with 45S5 BG, had similar mechanical strength and were stiffer than PLGA alone in compression, whilst all had a lower tensile strength. Dynamic mechanical analysis demonstrated an increased storage modulus (E') in the composites (other than the 45S5 BG filled PLGA). The effect of water uptake and early degradation was investigated by short-term in vitro aging in simulated body fluid, which indicated enhanced water uptake over the neat polymer; bioactive glass had the greatest water uptake, causing matrix plasticization. These results enable a direct comparison between bioactive filler type in poly(α-hydroxyester) composites, and have implications when selecting a composite material for eventual application in bone substitution. PMID:26164218

  8. A comparative study of the effects of different bioactive fillers in PLGA matrix composites and their suitability as bone substitute materials: A thermo-mechanical and in vitro investigation.

    PubMed

    Simpson, R L; Nazhat, S N; Blaker, J J; Bismarck, A; Hill, R; Boccaccini, A R; Hansen, U N; Amis, A A

    2015-10-01

    Bone substitute composite materials with poly(L-lactide-co-glycolide) (PLGA) matrices and four different bioactive fillers: CaCO3, hydroxyapatite (HA), 45S5 Bioglass(®) (45S5 BG), and ICIE4 bioactive glass (a lower sodium glass than 45S5 BG) were produced via melt blending, extrusion and moulding. The viscoelastic, mechanical and thermal properties, and the molecular weight of the matrix were measured. Thermogravimetric analysis evaluated the effect of filler composition on the thermal degradation of the matrix. Bioactive glasses caused premature degradation of the matrix during processing, whereas CaCO3 or HA did not. All composites, except those with 45S5 BG, had similar mechanical strength and were stiffer than PLGA alone in compression, whilst all had a lower tensile strength. Dynamic mechanical analysis demonstrated an increased storage modulus (E') in the composites (other than the 45S5 BG filled PLGA). The effect of water uptake and early degradation was investigated by short-term in vitro aging in simulated body fluid, which indicated enhanced water uptake over the neat polymer; bioactive glass had the greatest water uptake, causing matrix plasticization. These results enable a direct comparison between bioactive filler type in poly(α-hydroxyester) composites, and have implications when selecting a composite material for eventual application in bone substitution.

  9. Tissue engineering of the small intestine by acellular collagen sponge scaffold grafting.

    PubMed

    Hori, Y; Nakamura, T; Matsumoto, K; Kurokawa, Y; Satomi, S; Shimizu, Y

    2001-01-01

    Tissue engineering of the small intestine will prove a great benefit to patients suffering from short bowel disease. However cell seeding in tissue engineering, such as fetal cell use, is accompanied by problems of ethical issues, rejection, and short supply. To overcome these problems, we carried out an experimental study on tissue engineering of the small intestine by acellular collagen sponge scaffold grafting. We resected the 5 cm long jejunum from beagle dogs and reconstructed it by acellular collagen sponge grafting with a silicon tube stent. The graft was covered with the omentum. At 1 month after operation, the silicon stent was removed endoscopically. Animals were sacrificed 1 and 4 months after operation, and were examined microscopically. Neo-intestinal regeneration was observed and the intestinal mucosa covered the luminal side of the regenerated intestine across the anastomosis. Thus, the small intestine was regenerated by tissue engineering technology using an acellular collagen sponge scaffold.

  10. Pertactin deficient Bordetella pertussis present a better fitness in mice immunized with an acellular pertussis vaccine.

    PubMed

    Hegerle, N; Dore, G; Guiso, N

    2014-11-20

    Bordetella pertussis is the etiologic agent of whooping cough and has been the target of vaccination for over fifty years. The latest strategies include the use of acellular pertussis vaccines that induce specific immunity against few virulence factors amongst which pertactin is included in three and five component acellular pertussis vaccines. Recently, it has been reported that B. pertussis clinical isolates loose the production of this adhesin in regions reaching high vaccine coverage with vaccines targeting this virulence factor. We here demonstrate that isolates not producing pertactin are capable of sustaining longer infection as compared to pertactin producing isolates in an in vivo model of acellular pertussis immunization. Loosing pertactin production might thus provide a selective advantage to these isolates in this background, which could account for the upraise in prevalence of these pertactin deficient isolates in the population.

  11. Acellular comet assay: a tool for assessing variables influencing the alkaline comet assay.

    PubMed

    Kennedy, Erin K; McNamee, James P; Prud'homme Lalonde, Louise; Jones, Trevor; Wilkinson, Diana

    2012-01-01

    In this study, an acellular modification to the alkaline comet assay to further evaluate key variables within the assay that may influence the outcome of genotoxicity studies is described. This acellular comet assay can detect differences of 0.2 Gy of (60)Co gamma-ray radiation between 0 and 1 Gy and differences of 1 Gy between 0 and 8 Gy; thus, this assay is applicable for a wide range of DNA damage levels. It is also shown that DNA damage from different radiation energies was not significantly different from (60)Co gamma-ray. This assay displayed a statistical increase in DNA damage due to uncontrolled exposure to natural light; however, the slope of the dose-response curve for light-exposed samples was similar to that for samples protected from light. A comparison of the alkaline comet assay with the acellular comet assay allowed for the intrinsic repair capacity of the alkaline comet assay to be quantified.

  12. A decellularization methodology for the production of a natural acellular intestinal matrix.

    PubMed

    Maghsoudlou, Panagiotis; Totonelli, Giorgia; Loukogeorgakis, Stavros P; Eaton, Simon; De Coppi, Paolo

    2013-01-01

    Successful tissue engineering involves the combination of scaffolds with appropriate cells in vitro or in vivo. Scaffolds may be synthetic, naturally-derived or derived from tissues/organs. The latter are obtained using a technique called decellularization. Decellularization may involve a combination of physical, chemical, and enzymatic methods. The goal of this technique is to remove all cellular traces whilst maintaining the macro- and micro-architecture of the original tissue. Intestinal tissue engineering has thus far used relatively simple scaffolds that do not replicate the complex architecture of the native organ. The focus of this paper is to describe an efficient decellularization technique for rat small intestine. The isolation of the small intestine so as to ensure the maintenance of a vascular connection is described. The combination of chemical and enzymatic solutions to remove the cells whilst preserving the villus-crypt axis in the luminal aspect of the scaffold is also set out. Finally, assessment of produced scaffolds for appropriate characteristics is discussed. PMID:24145913

  13. THE IMPACT OF CHEMOTHERAPY AND RADIATION ON THE REMODELING OF ACELLULAR DERMAL MATRICES IN STAGED, PROSTHETIC BREAST RECONSTRUCTION

    PubMed Central

    Myckatyn, Terence M.; Cavallo, Jaime A.; Sharma, Ketan; Gangopadhyay, Noopur; Dudas, Jason R.; Roma, Andres A.; Baalman, Sara; Tenenbaum, Marissa M.; Matthews, Brent D.; Deeken, Corey R.

    2015-01-01

    Background An acellular dermal matrix (ADM) used in prosthetic breast reconstruction will typically incorporate, in time, with the overlying mastectomy skin flap. This remodeling process may be adversely impacted in patients that require chemotherapy and radiation therapies that influence neovascularization and cellular proliferation. Methods Multiple biopsies of the submuscular capsule and ADM were procured from 86 women (N=94 breasts) undergoing exchange of a tissue expander for a breast implant. These were divided by biopsy location : submuscular capsule (control) as well as superiorly, centrally and inferiorly along the ADM. Specimens were assessed grossly for incorporation and semi-quantitatively for cellular infiltration, cell type, fibrous encapsulation, scaffold degradation, extracellular matrix deposition, neovascularization, mean composite remodeling score, as well as Type I and III collagen area and ratio. Five oncologic treatment groups were compared : no adjuvant therapy (untreated), neoadjuvant chemotherapy ± radiation ; and chemotherapy ± radiation. Results ADM and submuscular capsule biopsies were procured 45 to 1805 days after ADM insertion and demonstrated a significant reduction in Type I collagen over time. Chemotherapy adversely impacted fibrous encapsulation relative to the untreated group (p=0.03). Chemotherapy with or without radiation adversely impacted Type I collagen area (p=0.02), cellular infiltration (p<0.01), extracellular matrix deposition (p<0.04), and neovascularization (p<0.01). Radiation exacerbated the adverse impact of chemotherapy for gross incorporation as well as several remodeling parameters. Neoadjuvant chemotherapy also caused a reduction in Type I (p=0.01) and III collagen (p=0.05), extracellular matrix deposition (p=0.03), and scaffold degradation (p=0.02). Conclusions Chemotherapy and radiation therapy limit ADM remodeling. PMID:25539350

  14. [Pertussis vaccines: acellular versus whole cell. Perhaps a return to the past?].

    PubMed

    Cofré, José

    2015-10-01

    The resurgence of pertussis in the world and in our country has questioned the effectiveness of cellular and acellular vaccines. The reason why pertussis has not been controlled or eliminated after 70 years of implementation of the vaccination is probably multifactorial. This article, on the basis of questions and answers, describes the benefits and limitations of both cellular and acellular vaccines and suggests new strategies of vaccination in childhood. It is a fact that the currently applied vaccination does not eliminate the circulation of Bordetella pertussis in the community. Perhaps the introduction of vaccines with live B. pertussis, inhalation, will be able to eliminate the disease around the world. PMID:26633113

  15. Extracellular bone matrix exhibits hardening elastoplasticity and more than double cortical strength: Evidence from homogeneous compression of non-tapered single micron-sized pillars welded to a rigid substrate.

    PubMed

    Luczynski, Krzysztof W; Steiger-Thirsfeld, Andreas; Bernardi, Johannes; Eberhardsteiner, Josef; Hellmich, Christian

    2015-12-01

    We here report an improved experimental technique for the determination of Young׳s modulus and uniaxial strength of extracellular bone matrix at the single micrometer scale, giving direct access to the (homogeneous) deformation (or strain) states of the tested samples and to the corresponding mechanically recoverable energy, called potential or elastic energy. Therefore, a new protocol for Focused Ion Beam milling of prismatic non-tapered micropillars, and attaching them to a rigid substrate, was developed. Uniaxial strength turns out as at least twice that measured macroscopically, and respective ultimate stresses are preceded by hardening elastoplastic states, already at very low load levels. The unloading portion of quasi-static load-displacement curves revealed Young׳s modulus of 29GPa in bovine extracellular bone matrix. This value is impressively confirmed by the corresponding prediction of a multiscale mechanics model for bone, which has been comprehensively validated at various other observation scales, across tissues from the entire vertebrate animal kingdom. PMID:25842157

  16. Recellularizing of human acellular dermal matrices imaged by high-definition optical coherence tomography.

    PubMed

    Boone, Marc A L M; Draye, Jean Pierre; Verween, Gunther; Aiti, Annalisa; Pirnay, Jean-Paul; Verbeken, Gilbert; De Vos, Daniel; Rose, Thomas; Jennes, Serge; Jemec, Gregor B E; Del Marmol, Veronique

    2015-05-01

    High-definition optical coherence tomography (HD-OCT) permits real-time 3D imaging of the impact of selected agents on human skin allografts. The real-time 3D HD-OCT assessment of (i) the impact on morphological and cellular characteristics of the processing of human acellular dermal matrices (HADMs) and (ii) repopulation of HADMs in vitro by human fibroblasts and remodelling of the extracellular matrix by these cells. Four different skin decellularization methods, Dispase II/Triton X-100, Dispase II/SDS (sodium dodecyl sulphate), NaCl/Triton X-100 and NaCl/SDS, were analysed by HD-OCT. HD-OCT features of epidermal removal, dermo-epidermal junction (DEJ) integrity, cellularity and dermal architecture were correlated with reflectance confocal microscopy (RCM), histopathology and immunohistochemistry. Human adult dermal fibroblasts were in vitro seeded on the NaCl/Triton X-100 processed HADMs, cultured up to 19 days and evaluated by HD-OCT in comparison with MTT proliferation test and histology. Epidermis was effectively removed by all treatments. DEJ was best preserved after NaCl/Triton X-100 treatment. Dispase II/SDS treatment seemed to remove all cellular debris in comparison with NaCl/Triton X-100 but disturbed the DEJ severely. The dermal micro-architectural structure and vascular spaces of (sub)papillary dermis were best preserved with the NaCl/Triton X-100. The impact on the 3D structure and vascular holes was detrimental with Dispase II/SDS. Elastic fibre fragmentation was only observed after Dispase II incubation. HD-OCT showed that NaCl/Triton X-100 processed matrices permitted in vitro repopulation by human dermal fibroblasts (confirmed by MTT test and histology) and underwent remodelling upon increasing incubation time. Care must be taken in choosing the appropriate processing steps to maintain selected properties of the extracellular matrix in HADMs. Processing HADMs with NaCl/Triton X-100 permits in vitro the proliferation and remodelling activity of

  17. Two-level contiguous cervical disc disease treated with peek cages packed with demineralized bone matrix: results of 3-year follow-up

    PubMed Central

    Topuz, Kıvanç; Çolak, Ahmet; Şimşek, Hakan; Kutlay, Murat; Demircan, Mehmet Nusret; Velioğlu, Murat

    2009-01-01

    Interbody cages are widely used instruments for cervical fusion operations. Long-term follow-up studies are needed to clarify if these devices are dependable. In this prospective study, 79 patients (42 women and 37 men) with a mean age of 51 years operated between January 2000 and December 2005 for treatment of degenerative cervical disc disease and spondylosis associated with radiculopathy or myelopathy were evaluated. Patients underwent two-level contiguous anterior cervical discectomy and fusion operations with standard anterior Smith–Robinson approach. To achieve fusion PEEK cages packed with demineralized bone matrix mixed with autologous blood were used. Clinical outcome was evaluated with Odom’s criteria and results were evaluated as ‘excellent’, ‘good’, ‘fair’ and ‘poor’. Spinal curves, mobility and fusion status were assessed with anterior–posterior and lateral (neutral, flexion and extension) radiographs obtained before surgery and at 3, 12, 24 and 36 months postoperatively. The Ishihara curvature index (ICI) was used for spinal curve evaluation. Lateral dynamic (flexion and extension) radiographs at postoperative 12th month revealed the fusion status classified as 1A, 1B, 2A and 2B. The radiological outcomes were classified as ‘non-fusion’ when 2B healing was observed, and as ‘fusion’ when 1A, 1B or 2A healing was observed at the levels subjected to surgery. According to Odom’s criteria, clinical outcomes were classified as ‘excellent’ or ‘good’ in 69 patients (success rate: 87.3%). Eight patients were graded as ‘fair’ and two as ‘poor’. Preoperative mean ICI was 10.4 ± 3.72 and postoperative mean ICI was 10.1 ± 3.14. The difference was statistically insignificant (P > 0.05); therefore, preoperative lordosis was said to be preserved at final follow-up. Final fusion rate (Types 1A, 1B, and 2A) was 91.7% (145/158 levels). Radiological imaging showed no cage failure or dislodgement and reoperation

  18. Method for fusing bone

    DOEpatents

    Mourant, Judith R.; Anderson, Gerhard D.; Bigio, Irving J.; Johnson, Tamara M.

    1996-01-01

    Method for fusing bone. The present invention is a method for joining hard tissue which includes chemically removing the mineral matrix from a thin layer of the surfaces to be joined, placing the two bones together, and heating the joint using electromagnetic radiation. The goal of the method is not to produce a full-strength weld of, for example, a cortical bone of the tibia, but rather to produce a weld of sufficient strength to hold the bone halves in registration while either external fixative devices are applied to stabilize the bone segments, or normal healing processes restore full strength to the tibia.

  19. Immunogenicity and safety of a monovalent, multicomponent acellular pertussis vaccine in 15 month-6-year-old German children. Monovalent Acellular Pertussis Vaccine Study Group.

    PubMed

    Stehr, K; Heininger, U; Uhlenbusch, R; Angersbach, P; Hackell, J; Eckhardt, T

    1995-03-01

    Immunization against pertussis has been re-recommended for healthy children in Germany in 1991. In addition the former restriction of immunizing only in the first 2 years of life was abolished. In children born before 1991 immunization rates against pertussis were 15% or less. With the new recommendations physicians are now faced with an increasing demand of parents for catch-up vaccinations in these children. Since they were immunized against diphtheria and tetanus previously monovalent pertussis vaccines are needed for this indication. Therefore a monovalent, multicomponent acellular pertussis vaccine was studied in 249 German children 15 months to 6 years of age. Three doses were administered at 6-10 week intervals. Reactogenicity and antibody responses against the vaccine antigens pertussis toxin (PT), filamentous haemagglutinin (FHA), 69-kd antigen (pertactin) and fimbriae-2 (agglutinogen) were investigated. Local and systemic reactions were minimal in frequency and severity. Antibody responses against all vaccine antigens were pronounced with 93%-100% of vaccinees demonstrating at least four fold titre rises above pre-immunization after the third dose. These findings indicate that this monovalent, multicomponent acellular pertussis vaccine with excellent immunogenicity and low reactogenicity is an appropriate candidate for closing immunization gaps in older children in countries with previously low vaccination rates against pertussis. Based on the results of this study the monovalent acellular pertussis vaccine was licensed in Germany in January 1994. PMID:7758519

  20. Strategies to eradicate minimal residual disease in small cell lung cancer: high-dose chemotherapy with autologous bone marrow transplantation, matrix metalloproteinase inhibitors, and BEC2 plus BCG vaccination.

    PubMed

    Krug, L M; Grant, S C; Miller, V A; Ng, K K; Kris, M G

    1999-10-01

    In the last 25 years, treatment for small cell lung cancer (SCLC) has improved with advances in chemotherapy and radiotherapy. Standard chemotherapy regimens can yield 80% to 90% response rates and some cures when combined with thoracic irradiation in limited-stage patients. Nonetheless, small cell lung cancer has a high relapse rate due to drug resistance; this has resulted in poor survival for most patients. Attacking this problem requires a unique approach to eliminate resistant disease remaining after induction therapy. This review will focus on three potential strategies: high-dose chemotherapy with autologous bone marrow transplantation, matrix metalloproteinase inhibitors, and BEC2 plus BCG vaccination.

  1. One-stage human acellular nerve allograft reconstruction for digital nerve defects

    PubMed Central

    Li, Xue-yuan; Hu, Hao-liang; Fei, Jian-rong; Wang, Xin; Wang, Tian-bing; Zhang, Pei-xun; Chen, Hong

    2015-01-01

    Human acellular nerve allografts have a wide range of donor origin and can effectively avoid nerve injury in the donor area. Very little is known about one-stage reconstruction of digital nerve defects. The present study observed the feasibility and effectiveness of human acellular nerve allograft in the reconstruction of < 5-cm digital nerve defects within 6 hours after injury. A total of 15 cases of nerve injury, combined with nerve defects in 18 digits from the Department of Emergency were enrolled in this study. After debridement, digital nerves were reconstructed using human acellular nerve allografts. The patients were followed up for 6–24 months after reconstruction. Mackinnon-Dellon static two-point discrimination results showed excellent and good rates of 89%. Semmes-Weinstein monofilament test demonstrated that light touch was normal, with an obvious improvement rate of 78%. These findings confirmed that human acellular nerve allograft for one-stage reconstruction of digital nerve defect after hand injury is feasible, which provides a novel trend for peripheral nerve reconstruction. PMID:25788927

  2. Decreased Laminin Expression by Human Lung Epithelial Cells and Fibroblasts Cultured in Acellular Lung Scaffolds from Aged Mice

    PubMed Central

    Godin, Lindsay M.; Sandri, Brian J.; Wagner, Darcy E.; Meyer, Carolyn M.; Price, Andrew P.; Akinnola, Ifeolu; Weiss, Daniel J.; Panoskaltsis-Mortari, Angela

    2016-01-01

    The lung changes functionally and structurally with aging. However, age-related effects on the extracellular matrix (ECM) and corresponding effects on lung cell behavior are not well understood. We hypothesized that ECM from aged animals would induce aging-related phenotypic changes in healthy inoculated cells. Decellularized whole organ scaffolds provide a powerful model for examining how ECM cues affect cell phenotype. The effects of age on ECM composition in both native and decellularized mouse lungs were assessed as was the effect of young vs old acellular ECM on human bronchial epithelial cells (hBECs) and lung fibroblasts (hLFs). Native aged (1 year) lungs demonstrated decreased expression of laminins α3 and α4, elastin and fibronectin, and elevated collagen, compared to young (3 week) lungs. Proteomic analyses of decellularized ECM demonstrated similar findings, and decellularized aged lung ECM contained less diversity in structural proteins compared to young ECM. When seeded in old ECM, hBECs and hLFs demonstrated lower gene expression of laminins α3 and α4, respectively, as compared to young ECM, paralleling the laminin deficiency of aged ECM. ECM changes appear to be important factors in potentiating aging-related phenotypes and may provide clues to mechanisms that allow for aging-related lung diseases. PMID:26954258

  3. Alterations in enhancer of zeste homolog 2, matrix metalloproteinase-2 and tissue inhibitor of metalloproteinase-2 expression are associated with ex vivo and in vitro bone metastasis in renal cell carcinoma.

    PubMed

    Wang, Jiang; Ren, Ye; Guo, Xin; Cheng, Hao; Ye, Yaping; Qi, Jun; Yang, Caihong; You, Hongbo

    2015-05-01

    Renal cell carcinoma (RCC) has a high potential for bone metastasis; however, the molecular mechanisms underlying this metastasis have remained to be elucidated. The present study aimed to explore the expression levels of enhancer of zeste homolog 2 (EZH2), matrix metalloproteinase-2 (MMP2) and tissue inhibitor of metalloproteinase-2 (TIMP2) as determinants of RCC-associated bone metastasis. Their expression was evaluated in a newly generated RCC cell subline that has a high potential for bone metastasis, in tissue specimens from metastasized bone tissues from patients with RCC and in RCC tissues without metastasis. A total of 25 RCC tissue specimens without metastasis and 13 RCC tissue specimens with bone metastasis were acquired for immunohistochemical analysis of EZH2, MMP2 and TIMP2 protein expression. The expression levels of EZH2, MMP2 and TIMP2 mRNA and protein were analyzed in the ACHN and ACHN-BO5 cell lines using western blot and reverse transcription polymerase chain reaction (PCR) analyses. Methylation-specific PCR was also used to analyze TIMP2 promoter methylation. EZH2 and MMP2 proteins were found to be expressed at higher levels in tissues from patients where RCC had metastasized to the bone as compared with those in RCC patients without metastasis, whereas there was no significant difference in the expression of TIMP2 protein between the two tissues. Furthermore, the expression of EZH2 protein was correlated with MMP2 expression, but there was no significant correlation between the expression of EZH2 and TIMP2 proteins. The in vitro results using cell lines confirmed the ex vivo findings, indicating that the expression levels of EZH2 and MMP2 protein and mRNA were higher in ACHN-BO5 cells than those in ACHN cells. By contrast, TIMP2 protein and mRNA expression levels were lower in ACHN-BO5 cells than those in the parental ACHN cells. The TIMP2 promoter was highly methylated in ACHN-BO5 cells compared with that in ACHN cells. Upregulation of EZH2

  4. Detection of irradiated ingredients included in low quantity in non-irradiated food matrix. 1. Extraction and ESR analysis of bones from mechanically recovered poultry meat.

    PubMed

    Marchioni, Eric; Horvatovich, Péter; Charon, Helène; Kuntz, Florent

    2005-05-18

    Protocol EN 1786 for the detection of irradiated food by electron spin resonance (ESR) spectroscopy was not conceived for the detection of irradiated bone-containing ingredients included in low concentration in non-irradiated food. An enzymatic hydrolysis method, realized at 55 degrees C, has been developed for the extraction of the bone fraction. When followed by a purification of the extracts by an aqueous solution of sodium polytungstate, this method made possible the detection of irradiated mechanically recovered poultry meat at very low inclusions (0.5%, wt/wt by ESR) in various meals (quenelles and precooked meals). PMID:15884794

  5. Bone scintiscanning updated.

    PubMed

    Lentle, B C; Russell, A S; Percy, J S; Scott, J R; Jackson, F I

    1976-03-01

    Use of modern materials and methods has given bone scintiscanning a larger role in clinical medicine, The safety and ready availability of newer agents have led to its greater use in investigating both benign and malignant disease of bone and joint. Present evidence suggests that abnormal accumulation of 99mTc-polyphosphate and its analogues results from ionic deposition at crystal surfaces in immature bone, this process being facilitated by an increase in bone vascularity. There is, also, a component of matrix localization. These factors are in keeping with the concept that abnormal scintiscan sites represent areas of increased osteoblastic activity, although this may be an oversimplification. Increasing evidence shows that the bone scintiscan is more sensitive than conventional radiography in detecting focal disease of bone, and its ability to reflect the immediate status of bone further complements radiographic findings. The main limitation of this method relates to nonspecificity of the results obtained.

  6. Structural changes and biological responsiveness of an injectable and mouldable monetite bone graft generated by a facile synthetic method.

    PubMed

    Cama, G; Gharibi, B; Knowles, J C; Romeed, S; DiSilvio, L; Deb, S

    2014-12-01

    Brushite (dicalcium phosphate dihydrate) and monetite (dicalcium phosphate anhydrous) are of considerable interest in bone augmentation owing to their metastable nature in physiological fluids. The anhydrous form of brushite, namely monetite, has a finer microstructure with higher surface area, strength and bioresorbability, which does not transform to the poorly resorbable hydroxyapatite, thus making it a viable alternative for use as a scaffold for engineering of bone tissue. We recently reported the formation of monetite cements by a simple processing route without the need of hydrothermal treatment by using a high concentration of sodium chloride in the reaction mix of β-tricalcium phosphate and monocalcium phosphate monohydrate. In this paper, we report the biological responsiveness of monetite formed by this method. The in vitro behaviour of monetite after interaction and ageing both in an acellular and cellular environment showed that the crystalline phase of monetite was retained over three weeks as evidenced from X-ray diffraction measurements. The crystal size and morphology also remained unaltered after ageing in different media. Human osteoblast cells seeded on monetite showed the ability of the cells to proliferate and express genes associated with osteoblast maturation and mineralization. Furthermore, the results showed that monetite could stimulate osteoblasts to undergo osteogenesis and accelerate osteoblast maturation earlier than cells cultured on hydroxyapatite scaffolds of similar porosity. Osteoblasts cultured on monetite cement also showed higher expression of osteocalcin, which is an indicator of the maturation stages of osteoblastogenesis and is associated with matrix mineralization and bone forming activity of osteoblasts. Thus, this new method of fabricating porous monetite can be safely used for generating three-dimensional bone graft constructs. PMID:25297314

  7. Structural changes and biological responsiveness of an injectable and mouldable monetite bone graft generated by a facile synthetic method

    PubMed Central

    Cama, G.; Gharibi, B.; Knowles, J. C.; Romeed, S.; DiSilvio, L.; Deb, S.

    2014-01-01

    Brushite (dicalcium phosphate dihydrate) and monetite (dicalcium phosphate anhydrous) are of considerable interest in bone augmentation owing to their metastable nature in physiological fluids. The anhydrous form of brushite, namely monetite, has a finer microstructure with higher surface area, strength and bioresorbability, which does not transform to the poorly resorbable hydroxyapatite, thus making it a viable alternative for use as a scaffold for engineering of bone tissue. We recently reported the formation of monetite cements by a simple processing route without the need of hydrothermal treatment by using a high concentration of sodium chloride in the reaction mix of β-tricalcium phosphate and monocalcium phosphate monohydrate. In this paper, we report the biological responsiveness of monetite formed by this method. The in vitro behaviour of monetite after interaction and ageing both in an acellular and cellular environment showed that the crystalline phase of monetite was retained over three weeks as evidenced from X-ray diffraction measurements. The crystal size and morphology also remained unaltered after ageing in different media. Human osteoblast cells seeded on monetite showed the ability of the cells to proliferate and express genes associated with osteoblast maturation and mineralization. Furthermore, the results showed that monetite could stimulate osteoblasts to undergo osteogenesis and accelerate osteoblast maturation earlier than cells cultured on hydroxyapatite scaffolds of similar porosity. Osteoblasts cultured on monetite cement also showed higher expression of osteocalcin, which is an indicator of the maturation stages of osteoblastogenesis and is associated with matrix mineralization and bone forming activity of osteoblasts. Thus, this new method of fabricating porous monetite can be safely used for generating three-dimensional bone graft constructs. PMID:25297314

  8. Structural changes and biological responsiveness of an injectable and mouldable monetite bone graft generated by a facile synthetic method.

    PubMed

    Cama, G; Gharibi, B; Knowles, J C; Romeed, S; DiSilvio, L; Deb, S

    2014-12-01

    Brushite (dicalcium phosphate dihydrate) and monetite (dicalcium phosphate anhydrous) are of considerable interest in bone augmentation owing to their metastable nature in physiological fluids. The anhydrous form of brushite, namely monetite, has a finer microstructure with higher surface area, strength and bioresorbability, which does not transform to the poorly resorbable hydroxyapatite, thus making it a viable alternative for use as a scaffold for engineering of bone tissue. We recently reported the formation of monetite cements by a simple processing route without the need of hydrothermal treatment by using a high concentration of sodium chloride in the reaction mix of β-tricalcium phosphate and monocalcium phosphate monohydrate. In this paper, we report the biological responsiveness of monetite formed by this method. The in vitro behaviour of monetite after interaction and ageing both in an acellular and cellular environment showed that the crystalline phase of monetite was retained over three weeks as evidenced from X-ray diffraction measurements. The crystal size and morphology also remained unaltered after ageing in different media. Human osteoblast cells seeded on monetite showed the ability of the cells to proliferate and express genes associated with osteoblast maturation and mineralization. Furthermore, the results showed that monetite could stimulate osteoblasts to undergo osteogenesis and accelerate osteoblast maturation earlier than cells cultured on hydroxyapatite scaffolds of similar porosity. Osteoblasts cultured on monetite cement also showed higher expression of osteocalcin, which is an indicator of the maturation stages of osteoblastogenesis and is associated with matrix mineralization and bone forming activity of osteoblasts. Thus, this new method of fabricating porous monetite can be safely used for generating three-dimensional bone graft constructs.

  9. Function of osteocytes in bone.

    PubMed

    Aarden, E M; Burger, E H; Nijweide, P J

    1994-07-01

    Although the structural design of cellular bone (i.e., bone containing osteocytes that are regularly spaced throughout the bone matrix) dates back to the first occurrence of bone as a tissue in evolution, and although osteocytes represent the most abundant cell type of bone, we know as yet little about the role of the osteocyte in bone metabolism. Osteocytes descend from osteoblasts. They are formed by the incorporation of osteoblasts into the bone matrix. Osteocytes remain in contact with each other and with cells on the bone surface via gap junction-coupled cell processes passing through the matrix via small channels, the canaliculi, that connect the cell body-containing lacunae with each other and with the outside world. During differentiation from osteoblasts to mature osteocyte the cells lose a large part of their cell organelles. Their cell processes are packed with microfilaments. In this review we discuss the various theories on osteocyte function that have taken in consideration these special features of osteocytes. These are 1) osteocytes are actively involved in bone turnover; 2) the osteocyte network is through its large cell-matrix contact surface involved in ion exchange; and 3) osteocytes are the mechanosensory cells of bone and play a pivotal role in functional adaptation of bone. In our opinion, especially the last theory offers an exciting concept for which some biomechanical, biochemical, and cell biological evidence is already available and which fully warrants further investigations.

  10. Method for fusing bone

    DOEpatents

    Mourant, J.R.; Anderson, G.D.; Bigio, I.J.; Johnson, T.M.

    1996-03-12

    The present invention is a method for joining hard tissue which includes chemically removing the mineral matrix from a thin layer of the surfaces to be joined, placing the two bones together, and heating the joint using electromagnetic radiation. The goal of the method is not to produce a full-strength weld of, for example, a cortical bone of the tibia, but rather to produce a weld of sufficient strength to hold the bone halves in registration while either external fixative devices are applied to stabilize the bone segments, or normal healing processes restore full strength to the tibia.

  11. Bone Grafts

    MedlinePlus

    A bone graft transplants bone tissue. Surgeons use bone grafts to repair and rebuild diseased bones in your hips, knees, ... fractures or cancers. Once your body accepts the bone graft, it provides a framework for growth of new, ...

  12. Bone Diseases

    MedlinePlus

    ... avoid smoking and drinking too much alcohol. Bone diseases can make bones easy to break. Different kinds ... break Osteogenesis imperfecta makes your bones brittle Paget's disease of bone makes them weak Bones can also ...

  13. Fiber-matrix interface studies on bioabsorbable composite materials for internal fixation of bone fractures. II. A new method using laser scanning confocal microscopy.

    PubMed

    Slivka, M A; Chu, C C

    1997-12-01

    In this study, a new visual characterization method was developed using laser scanning confocal microscopy (LSCM) to study morphologic properties, particularly at the fiber-matrix interface, by optical sectioning of bioabsorbable single-fiber composites. The interface gap width (IGW) between the fiber and matrix, and the changes in IGW after in vitro hydrolysis, named the gap rate (Rg), were measured from images obtained using the LSCM. Higher values for IGW and Rg showed faster degradation of the fiber-matrix interface. These parameters were used to investigate the effects of strain, wicking, different reinforcing fibers, and gamma-irradiation on the fiber-matrix interface morphology. The component materials used were nonbioabsorbable AS4 carbon (C) fibers, bioabsorbable calcium phosphate (CaP), poly(glycolic acid) (PGA), and chitin fibers, and bioabsorbable poly(L-lactic acid) (PLLA) matrix. The application of strain on CaP/PLLA composites increased the IGW up to about 15%, after which there was no change up to 25%. The Rg for CaP/PLLA composites with the fiber ends exposed in vitro (permitting wicking) was greater than for CaP/PLLA with the fiber ends embedded completely within the matrix (preventing wicking). Open-end C/PLLA composites had the slowest rate of interface degradation in vitro, followed by chitin/PLLA, PGA/PLLA, and CaP/PLLA. The exposure of closed-end CaP/PLLA composites to 4 Mrad of gamma-irradiation, in air at room temperature or in vaccuum at 77K, accelerated the rate of interface degradation in vitro. In conclusion, an effective new visual characterization method was developed using LSCM, and it was used to show that (a) moderate strain could accelerate the degradation of the interface, (b) fiber-matrix interface wicking could accelerate the rate of degradation of the interface, (c) the rate of interface degradation depends on the type of fiber used, and (d) gamma-irradiation could accelerate the rate of interface degradation. Furthermore, the

  14. Microdamage induced calcium efflux from bone matrix activates intracellular calcium signaling in osteoblasts via L-type and T-type voltage-gated calcium channels.

    PubMed

    Jung, Hyungjin; Best, Makenzie; Akkus, Ozan

    2015-07-01

    Mechanisms by which bone microdamage triggers repair response are not completely understood. It has been shown that calcium efflux ([Ca(2+)]E) occurs from regions of bone undergoing microdamage. Such efflux has also been shown to trigger intracellular calcium signaling ([Ca(2+)]I) in MC3T3-E1 cells local to damaged regions. Voltage-gated calcium channels (VGCCs) are implicated in the entry of [Ca(2+)]E to the cytoplasm. We investigated the involvement of VGCC in the extracellular calcium induced intracellular calcium response (ECIICR). MC3T3-E1 cells were subjected to one dimensional calcium efflux from their basal aspect which results in an increase in [Ca(2+)]I. This increase was concomitant with membrane depolarization and it was significantly reduced in the presence of Bepridil, a non-selective VGCC inhibitor. To identify specific type(s) of VGCC in ECIICR, the cells were treated with selective inhibitors for different types of VGCC. Significant changes in the peak intensity and the number of [Ca(2+)]I oscillations were observed when L-type and T-type specific VGCC inhibitors (Verapamil and NNC55-0396, respectively) were used. So as to confirm the involvement of L- and T-type VGCC in the context of microdamage, cells were seeded on devitalized notched bone specimen, which were loaded to induce microdamage in the presence and absence of Verapamil and NNC55-0396. The results showed significant decrease in [Ca(2+)]I activity of cells in the microdamaged regions of bone when L- and T-type blockers were applied. This study demonstrated that extracellular calcium increase in association with damage depolarizes the cell membrane and the calcium ions enter the cell cytoplasm by L- and T-type VGCCs.

  15. The Cellular Immune Mechanism after Transfer of Chemically Extracted Acellular Nerve Xenografts

    PubMed Central

    Lin, Xingshi; Yang, Ruojia; He, Qing; Ruan, Dike

    2013-01-01

    Severe peripheral nerve defect by injuries causing functional loss require nerve grafting. Autograft has limitations for clinical use because it results in the creation of a new nerve injury and the generation of donor site morbidity. Based on these limitations, nerve allografts and xenografts provide a readily accessible alternative strategy. The aim of the present study was to observe the immune mechanism underlying the rejection of chemically extracted acellular nerve xenografts, and further evaluate immunogenicity of chemically treated acellular nerve grafts for clinical applications. A total of 160 BALB/c mice were randomly divided into a negative contrast group (NC, 40 mice), a fresh autograft group (AG, 40 mice), a fresh xenogeneic nerve group (FXN, 40 mice) and a chemically extracted acellular xenogeneic nerve group (CEXN, 40 mice). Various types of nerve grafts were implanted into the thigh muscle of BALB/C mice in the corresponding groups. At 3, 7, 14 and 28 days post-operation, the mice (10 mice from each group) were sacrificed and their spleens were extracted. The spleens were ground into paste. The erythrocytes and other cells were lysed using distilled water and the T lymphocytes were collected. Fluorescein isothiocyanate (FITC) -labeled monoclonal antibodies (CD3, CD4, CD8, CD25, IL-2, IFN-γ and TNF-α) were then added to the solution. The Fluorescence Activated Cell Sorting (FACS) was used to determine the positivity rate of the cells combined with the monoclonal antibodies above. No significant statistical differences were observed between the CEXN, NC and AG groups, so that no obvious immune rejections were observed among the chemically extracted acellular nerve xenografts. PMID:23874771

  16. Genetics of aging bone.

    PubMed

    Adams, Douglas J; Rowe, David W; Ackert-Bicknell, Cheryl L

    2016-08-01

    With aging, the skeleton experiences a number of changes, which include reductions in mass and changes in matrix composition, leading to fragility and ultimately an increase of fracture risk. A number of aspects of bone physiology are controlled by genetic factors, including peak bone mass, bone shape, and composition; however, forward genetic studies in humans have largely concentrated on clinically available measures such as bone mineral density (BMD). Forward genetic studies in rodents have also heavily focused on BMD; however, investigations of direct measures of bone strength, size, and shape have also been conducted. Overwhelmingly, these studies of the genetics of bone strength have identified loci that modulate strength via influencing bone size, and may not impact the matrix material properties of bone. Many of the rodent forward genetic studies lacked sufficient mapping resolution for candidate gene identification; however, newer studies using genetic mapping populations such as Advanced Intercrosses and the Collaborative Cross appear to have overcome this issue and show promise for future studies. The majority of the genetic mapping studies conducted to date have focused on younger animals and thus an understanding of the genetic control of age-related bone loss represents a key gap in knowledge.

  17. Mechanical properties of acellular mouse lungs after sterilization by gamma irradiation.

    PubMed

    Uriarte, Juan J; Nonaka, Paula N; Campillo, Noelia; Palma, Renata K; Melo, Esther; de Oliveira, Luis V F; Navajas, Daniel; Farré, Ramon

    2014-12-01

    Lung bioengineering using decellularized organ scaffolds is a potential alternative for lung transplantation. Clinical application will require donor scaffold sterilization. As gamma-irradiation is a conventional method for sterilizing tissue preparations for clinical application, the aim of this study was to evaluate the effects of lung scaffold sterilization by gamma irradiation on the mechanical properties of the acellular lung when subjected to the artificial ventilation maneuvers typical within bioreactors. Twenty-six mouse lungs were decellularized by a sodium dodecyl sulfate detergent protocol. Eight lungs were used as controls and 18 of them were submitted to a 31kGy gamma irradiation sterilization process (9 kept frozen in dry ice and 9 at room temperature). Mechanical properties of acellular lungs were measured before and after irradiation. Lung resistance (RL) and elastance (EL) were computed by linear regression fitting of recorded signals during mechanical ventilation (tracheal pressure, flow and volume). Static (Est) and dynamic (Edyn) elastances were obtained by the end-inspiratory occlusion method. After irradiation lungs presented higher values of resistance and elastance than before irradiation: RL increased by 41.1% (room temperature irradiation) and 32.8% (frozen irradiation) and EL increased by 41.8% (room temperature irradiation) and 31.8% (frozen irradiation). Similar increases were induced by irradiation in Est and Edyn. Scanning electron microscopy showed slight structural changes after irradiation, particularly those kept frozen. Sterilization by gamma irradiation at a conventional dose to ensure sterilization modifies acellular lung mechanics, with potential implications for lung bioengineering. PMID:25241281

  18. Management of complex abdominal wall defects using acellular porcine dermal collagen.

    PubMed

    Chavarriaga, Luis Felipe; Lin, Edward; Losken, Albert; Cook, Michael W; Jeansonne, Louis O; White, Brent C; Sweeney, John F; Galloway, John R; Davis, S Scott

    2010-01-01

    Multiple techniques have been used for the repair of complex abdominal wall defects after recurrent incisional hernias with varying rates of success. Primary repair has been associated with high recurrence rates, and prosthetic mesh placement is contraindicated in contaminated surgical fields. The development of biologic prostheses has changed the approach to these difficult problems. This study evaluates the management of complex abdominal wall defects using acellular porcine dermal collagen. Between August 2006 and May 2007, 18 patients underwent abdominal wall reconstruction for complex defects with acellular porcine dermal collagen (CollaMend; Bard Inc., Warwick, RI). Patient demographics, preoperative risk factors, previous herniorrhaphy attempts, postoperative complications, recurrences, and long-term results were retrospectively reviewed. Records were reviewed at a mean follow up of 7.3 months; the recurrence rate was 44.4 per cent. A total of 38.9 per cent (seven of 18) developed a postoperative wound complications, including infection in 22.2 per cent (four of 18). All of the patients with infection required prosthesis removal as a result of encapsu