Science.gov

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. Data from acellular human heart matrix.

    PubMed

    Sánchez, Pedro L; Fernández-Santos, M Eugenia; Espinosa, M Angeles; González-Nicolas, M Angeles; Acebes, Judith R; Costanza, Salvatore; Moscoso, Isabel; Rodríguez, Hugo; García, Julio; Romero, Jesús; Kren, Stefan M; Bermejo, Javier; Yotti, Raquel; Del Villar, Candelas Pérez; Sanz-Ruiz, Ricardo; Elizaga, Jaime; Taylor, Doris A; Fernández-Avilés, Francisco

    2016-09-01

    Perfusion decellularization of cadaveric hearts removes cells and generates a cell-free extracellular matrix scaffold containing acellular vascular conduits, which are theoretically sufficient to perfuse and support tissue-engineered heart constructs. This article contains additional data of our experience decellularizing and testing structural integrity and composition of a large series of human hearts, "Acellular human heart matrix: a critical step toward whole heat grafts" (Sanchez et al., 2015) [1]. Here we provide the information about the heart decellularization technique, the valve competence evaluation of the decellularized scaffolds, the integrity evaluation of epicardial and myocardial coronary circulation, the pressure volume measurements, the primers used to assess cardiac muscle gene expression and, the characteristics of donors, donor hearts, scaffolds and perfusion decellularization process. PMID:27331090

  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. 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

  7. The use of acellular dermal matrix as a scaffold for periosteum replacement.

    PubMed

    Beniker, Dan; McQuillan, David; Livesey, Stephen; Urban, Robert M; Turner, Thomas M; Blum, Barbara; Hughes, Kim; Haggard, Warren O

    2003-05-01

    Three preclinical models were used to evaluate GraftJacket Acellular Periosteum Replacement Scaffold (Wright Medical Technology, Inc, Arlington, Tenn). The studies assessed the ability of the acellular dermal matrix to repopulate with cells, revascularize, provide a protected environment for bone defect restoration, and minimize fibrous tissue infiltration. An athymic nude rat muscle implantation study demonstrated a steady increase in cellular repopulation through days 2-21. The formation of blood vessels occurred between days 7-14 in this study. Results from a porcine femoral drill hole study indicated that the scaffold material was intact and adherent to surrounding bone and allowed cellular repopulation and vascular infiltration at a 5-week time period. A preliminary porcine segmental bone defect model at a 6-week time period demonstrated the ability of the scaffold material to protect the bone defect site as revealed by new bone formation within the margins of the defect and adjacent to the scaffold. The segmental model also indicated minimal to no soft tissue invasion into the defect site. The combined studies provided preliminary evidence that the dermal membrane material may be used as a scaffold for periosteum regeneration by allowing for cellular repopulation, revascularization, and bone defect restoration. PMID:12755232

  8. 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

  9. Use of an Acellular Regenerative Tissue Matrix Over Chronic Wounds

    PubMed Central

    Stacey, D. Heath

    2013-01-01

    Objectives: Bioengineered skin grafts, including acellular dermal matrices, may be effective in treating lower extremity and trunk wounds that are not responsive to traditional wound management. Acellular dermal wound matrix is derived from human acellular dermal wound matrix (HADWM) tissue and provides a scaffold that supports cellular repopulation and revascularization. The major structural components of the dermis are retained during processing, and a single application has been shown to help achieve wound closure. Methods: This patient case series examined the use of HADWM on lower extremity and trunk wounds in 11 patients (6 male and 5 female) with a mean age of 55 years (range: 31–83 years). Wounds were debrided 1 to 2 times, followed by placement of HADWM (range: 4–330 cm2) on wounds that varied from the dorsal surface of the foot, lower abdomen, and lower extremity to the Achilles flap. A nonadherent layer in conjunction with bacitracin was placed over HADWM. Negative pressure wound therapy (NPWT) was placed over the HADWM and initiated continuously at −125 mm Hg for 1 to 2 weeks. After the application of NPWT, HADWM was covered with various gauze dressings using mineral oil. Results: All patients completed their treatment successfully, and follow-up ranged from 1 week to 6 months. One patient experienced an infection, which resulted in partial graft loss that required replacement with HADWM and NPWT. No additional complications occurred in the other patients. Conclusions: This patient case series demonstrated successful use of HADWM and NPWT, which further supports published studies documenting HADWM success in chronic wounds. PMID:24324850

  10. 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

  11. 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

  12. Management of failed and infected first metatarsophalangeal joint implant arthroplasty by reconstruction with an acellular dermal matrix: a case report.

    PubMed

    Khoury, Wissam E; Fahim, Ramy; Sciulli, Jessica M; Ehredt, Duane J

    2012-01-01

    Management of failed first metatarsophalangeal joint implant arthroplasty, especially in the face of infection, is an area of debate without a clear consensus. The purpose of the present report was to explore a new option of reconstructing the joint with an acellular dermal matrix substance in a single case study during a 12-month follow-up period. A staged approach that began with removal of the failed 2-component great toe implant, Koenig(®), excisional debridement of the wound with resection of the necrotic bone (proximal phalanx and distal portion of the first metatarsal bones), and culture-specific antibiosis therapy. The final stage included incorporating the acellular dermal matrix, Graftjacket(®) into the joint in an accordion-type fashion, and reconstruction of the joint capsule. Postoperative radiographs revealed a more rectus joint with some improvement in length. At 6 months postoperatively, magnetic resonance imaging revealed incorporation of the graft material into the joint. Finally, at the 1-year mark, the patient was pain free with satisfactory function at the first metatarsophalangeal joint during gait. This is the first reported case of salvaging failed and infected first metatarsophalangeal joint implant arthroplasty with incorporation of the acellular dermal matrix and provides a new option to consider in the future. PMID:22704789

  13. Spherical indentation of free-standing acellular extracellular matrix membranes.

    PubMed

    Cloonan, Aidan J; O'Donnell, Michael R; Lee, William T; Walsh, Michael T; De Barra, Eamonn; McGloughlin, Tim M

    2012-01-01

    Numerous scaffold materials have been developed for tissue engineering and regenerative medicine applications to replace or repair damaged tissues and organs. Naturally occurring scaffold materials derived from acellular xenogeneic and autologous extracellular matrix (ECM) are currently in clinical use. These biological scaffold materials possess inherent variations in mechanical properties. Spherical indentation or ball burst testing has commonly been used to evaluate ECM and harvested tissue due to its ease of use and simulation of physiological biaxial loading, but has been limited by complex material deformation profiles. An analytical methodology has been developed and applied to experimental load-deflection data of a model hyperelastic material and lyophilized ECM scaffolds. An optimum rehydration protocol was developed based on water absorption, hydration relaxation and dynamic mechanical analysis. The analytical methodology was compared with finite element simulations of the tests and excellent correlation was seen between the computed biaxial stress resultants and geometry deformations. A minimum rehydration period of 5 min at 37°C was sufficient for the evaluated multilaminated ECM materials. The proposed approach may be implemented for convenient comparative analysis of ECM materials and source tissues, process optimization or during lot release testing. PMID:21864728

  14. 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

  15. 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

  16. 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

  17. 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

  18. 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

  19. 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

  20. 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

  1. 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

  2. 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

  3. Outcomes of allogenic acellular matrix therapy in treatment of diabetic foot wounds: an initial experience.

    PubMed

    Martin, Billy R; Sangalang, Melinda; Wu, Stephanie; Armstrong, David G

    2005-06-01

    The purpose of this study was to evaluate outcomes of persons with UT grade 2A neuropathic diabetic foot wounds treated with an acellular matrix. Data were abstracted for 17 consecutive patients with diabetes--76.5% males, aged 61.5 +/- 8.5 years with a mean glycated haemoglobin of 9.2 +/- 2.2% presenting for care at a large, multidisciplinary wound care centre. All patients received surgical debridement for their diabetic foot wounds and were placed on therapy consisting of a single application of an acellular matrix graft (GraftJacket; Wright Medical Technologies, Arlington, TN, USA) with dressing changes taking place weekly. Outcomes evaluated included time to complete wound closure and proportion of patients achieving wound closure in 20 weeks. Acellular matrix therapy was used as initial therapy and was sutured or stapled in place under a silicone-based non adherent dressing. Therapy was then followed by a moisture-retentive dressing until complete epithelialisation. In total, 82.4% of wounds measuring a mean 4.6 +/- 3.2 cm(2) healed in the 20-week evaluation period. For those that healed in this period, healing took place in a mean 8.9 +/- 2.7 weeks. We conclude that a regimen consisting of moist wound healing using an acellular matrix dressing may be a useful adjunct to appropriate diabetic foot ulcer care for deep, non-infected, non-ischaemic wounds. We await the completion of further trials in this area to confirm or refute this initial assessment. PMID:16722865

  4. 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. PMID:14763548

  5. Biomechanical evaluation of acellular collagen matrix augmented Achilles tendon repair in sheep.

    PubMed

    Song, Lin; Olsen, Raymond E; Spalazzi, Jeffrey P; Davisson, Twana

    2010-01-01

    The rate of rerupture of repaired Achilles tendon in young and athletic populations remains high despite improvement in surgical techniques, suture design, and postsurgical management. Acellular biological matrices can be used to enhance the immediate strength of repaired tendons and to serve as scaffolds for cell in-growth and constructive tissue remodeling. A number of commercially available matrices have been used clinically, albeit with varying degrees of success and failure. The disparity is likely attributable to the different physical and biochemical properties of individual matrices. In this study, we investigated the biomechanical characteristics of 2 different acellular collagen matrices, namely TissueMend and GraftJacket, using a sheep Achilles tendon repair model. Static and cyclic creep, cyclic and linear construct stiffness, maximum load to failure, and displacement at maximum load were determined at time zero. We found that the maximum load to failure, displacement, and ultimate failure mode were similar between tendons augmented with either acellular collagen matrix; however, TissueMend augmentation yielded lower creep and smaller construct elongation than did GraftJacket. The results indicated that the strength of TissueMend-augmented tendons and GraftJacket-augmented tendons was not statistically significantly different, although tendons augmented with TissueMend displayed greater stiffness, which may be clinically advantageous in the restoration of ruptured tendons. PMID:20797586

  6. 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

  7. 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

  8. Constructing Human Skin Equivalents on Porcine Acellular Peritoneum Extracellular Matrix for In Vitro Irritation Testing.

    PubMed

    Tsai, Pei-Chin; Zhang, Zheng; Florek, Charles; Michniak-Kohn, Bozena B

    2016-01-01

    The irritancy of topical products has to be investigated to ensure the safety and compliance. Although several reconstructed human epidermal models have been adopted by the Organization for Economic Cooperation and Development (OECD) to replace in vivo animal irritation testing, these models are based on a single cell type and lack dermal components, which may be insufficient to reflect all of the components of irritation. In our study, we investigated the use of acellular porcine peritoneum extracellular matrix as a substrate to construct full-thickness human skin equivalents (HSEs) for use as irritation screening tool. The acellular peritoneum matrix (APM) exhibited excellent skin cell attachment (>80%) and proliferation for human dermal fibroblasts (HDF) and immortalized human keratinocytes (HaCaT). APM-HSEs based on coculture of HDF and HaCaT were prepared. Increased HDF seeding density up to 5 × 10(4)/cm(2) resulted in APM-HSEs with a thicker and more organized epidermis. The epidermis of APM-HSEs expressed keratin 15, a keratinocyte proliferation marker, and involucrin, a differentiation marker, respectively. To assess the use of APM-HSEs for irritation testing, six proficiency chemicals, including three nonirritants (phosphate-buffered saline, polyethylene glycol 400, and isopropanol) and three irritants (1-bromohexane, heptanol, and sodium dodecyl sulfate) were applied. The APM-HSEs were able to discriminate nonirritants from irritants based on the viability. Levels of cytokines (interleukin [IL]-1α, IL-1ra, IL-6, IL-8, and granulocyte macrophage colony-stimulating factor [GM-CSF]) in these treatment groups further assisted the irritancy ranking. In conclusion, we have developed partially differentiated full-thickness APM-HSEs based on acellular porcine peritoneum matrix, and these APM-HSEs demonstrated utility as an in vitro irritation screening tool. PMID:26415037

  9. 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

  10. 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

  11. Cellular Response to a Novel Fetal Acellular Collagen Matrix: Implications for Tissue Regeneration

    PubMed Central

    Rennert, Robert C.; Garg, Ravi K.; Gurtner, Geoffrey C.

    2013-01-01

    Introduction. PriMatrix (TEI Biosciences Inc., Boston, MA, USA) is a novel acellular collagen matrix derived from fetal bovine dermis that is designed for use in partial- and full-thickness wounds. This study analyzes the cellular response to PriMatrix in vivo, as well as the ability of this matrix to facilitate normal tissue regeneration. Methods. Five by five mm squares of rehydrated PriMatrix were implanted in a subcutaneous fashion on the dorsum of wild-type mice. Implant site tissue was harvested for histology, immunohistochemistry (IHC), and flow cytometric analyses at multiple time points until day 28. Results. PriMatrix implants were found to go through a biological progression initiated by a transient infiltrate of inflammatory cells, followed by mesenchymal cell recruitment and vascular development. IHC analysis revealed that the majority of the implanted fetal dermal collagen fibers persisted through day 28 but underwent remodeling and cellular repopulation to form tissue with a density and morphology consistent with healthy dermis. Conclusions. PriMatrix implants undergo progressive in vivo remodeling, facilitating the regeneration of histologically normal tissue through a mild inflammatory and progenitor cell response. Regeneration of normal tissue is especially important in a wound environment, and these findings warrant further investigation of PriMatrix in this setting. PMID:23970899

  12. 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

  13. 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. PMID:25890761

  14. Human acellular dermal matrix for repair of abdominal wall defects: review of clinical experience and experimental data.

    PubMed

    Holton, Luther H; Kim, Daniel; Silverman, Ronald P; Rodriguez, Eduardo D; Singh, Navin; Goldberg, Nelson H

    2005-01-01

    The use of prosthetic mesh for the tension-free repair of incisional hernias has been shown to be more effective than primary suture repair. Unfortunately, prosthetic materials can be a suboptimal choice in a variety of clinical scenarios. In general, prosthetic materials should not be implanted into sites with known contamination or infection because they lack an endogenous vascular network and are thus incapable of clearing bacteria. This is of particular relevance to the repair of recurrent hernias, which are often refractory to repair because of indolent bacterial colonization that weakens the site and retards appropriate healing. Although fascia lata grafts and muscle flaps can be employed for tension-free hernia repairs, they carry the potential for significant donor site morbidity. Recently, a growing number of clinicians have used human acellular dermal matrix as a graft material for the tension-free repair of ventral hernias. This material has been shown to become revascularized in both animal and human subjects. Once repopulated with a vascular network, this graft material is theoretically capable of clearing bacteria, a property not found in prosthetic graft materials. Unlike autologous materials such as fascial grafts and muscle flaps, acellular dermal matrix can be used without subjecting the patient to additional morbidity in the form of donor site complications. This article presents a thorough review of the current literature, describing the properties of human acellular dermal matrix and discussing both animal and human studies of its clinical performance. In addition to the review of previously published clinical experiences, we discuss our own preliminary results with the use of acellular dermal matrix for ventral hernia repair in 46 patients. PMID:16218902

  15. Treatment of severe burn with DermACELL®, an acellular dermal matrix

    PubMed Central

    Chen, Shyi-Gen; Tzeng, Yuan-Sheng; Wang, Chih-Hsin

    2012-01-01

    For treatment of skin burn injuries, there exist several methods of treatment related to tissue regeneration, including the use of autograft skin and cryopreserved skin. However, each method has drawbacks. An alternative method for tissue regeneration is allograft acellular dermal matrix, with potential as a biocompatible scaffold for new tissue growth. One recently produced material of this type is DermACELL®, which was used in this case presentation for treating a scar resulting from second- and third-degree burns in a 33-year-old female patient. The patient presented with significant hypertrophic scarring from the elbow to the hand and with limited wrist and elbow motion. The scarring was removed, and the patient was treated with a 1:3 mesh of DermACELL. The wound was resurfaced with a split thickness skin graft, and postoperative care included application of pressure garment and silicone sheet, as well as range of motion exercise and massage. At 30 days after DermACELL application, the wound appeared well-healed with little scar formation. At 180 days post-application, the wound continued to appear healed well without significant scar formation. Additionally, the wound was supple, and the patient experienced significant improvement in range of motion. In the case presented, DermACELL appears to have been a successful method of treatment for scarring due to severe burns by preventing further scar formation and improving range of motion. PMID:23071908

  16. 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

  17. 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

  18. 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

  19. Pancreatic acellular matrix supports islet survival and function in a synthetic tubular device: in vitro and in vivo studies.

    PubMed

    De Carlo, E; Baiguera, S; Conconi, M T; Vigolo, S; Grandi, C; Lora, S; Martini, C; Maffei, P; Tamagno, G; Vettor, R; Sicolo, N; Parnigotto, P P

    2010-02-01

    Increasing pancreatic islet survival and function is a starting point for obtaining a valuable bioartificial pancreas for the treatment of type 1 diabetes. In this context, decellularized matrices, obtained after the removal of tissue cellular part, are known to support in vitro adhesion, growth, and function of several cell types. We demonstrate that a homologous acellular pancreatic matrix is a suitable scaffold for rat islet cultures maintaining their long-term viability and function. Islets adhered to the pancreatic matrix showed a constant glucose-induced insulin release during long-term in vitro incubation, while islets cultured without a matrix or on the liver matrix showed a progressive reduction. In order to obtain implantable devices, acellular matrix/islet cultures were entrapped into poly(vinyl alcohol) (PVA)/ poly(ethylene glycol) (PEG) tubes obtained by the freezing/thawing procedure. Under this condition, an in vitro constant insulin release was detected. The devices were then implanted into diabetic rats where reduced insulin requirement was noted suggesting insulin secretory activity of islets contained in the device. Indeed, immunofluorescence confirmed the presence of insulin- and glucagon-producing cells into the explanted devices. These data show that PVA/PEG semi-permeable membrane can obtain devices that restore, at least in part, insulin secretion. PMID:20043127

  20. 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

  1. 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

  2. The use of an acellular collagen matrix in penile augmentation: A pilot study in Saudi Arabia

    PubMed Central

    Tealab, Alaa A.; Maarouf, Aref M.; Habous, Mohamed; Ralph, David J.; Abohashem, Safwat

    2013-01-01

    Objectives To assess the use of an acellular collagen matrix (Pelvicol, Bard Medical, Covington, GA, USA), a successful agent for reconstructive surgery, for enhancing penile girth. Patients and methods Between June and December 2011, 18 patients (mean age 24 years, range 19–38) had their penis augmented with Pelvicol; the mean (range) penile circumference was 9.2 (7–13) cm before treatment. They were divided into two groups; the first (10 patients) had a Pelvicol sheet of 8 × 12 cm inserted through a V–Y suprapubic incision and wrapped around the shaft in a bilayer under the dartos fascia, but not covering the urethra, with division of the suspensory ligament. The second group of eight patients had the Pelvicol inserted through a subcoronal degloving incision and placed in one layer. The penile circumference was measured at 6 and 12 months after surgery. Patient satisfaction at 1 year after surgery was assessed as ‘poor’, ‘unsatisfied’, ‘moderately satisfied’, ‘highly satisfied’, or ‘excellent’. Results The mean (range) increase in girth (circumference) was 2.8 (2–3.2) cm in group 1 and 1.7 (1.2–2) cm in group 2. In group 1, two patients were highly satisfied, four moderately satisfied and four unsatisfied; in group 2, three were moderately satisfied and five unsatisfied. Complications were common in both groups, with five patients in group 1 and three in group 2 developing severe penile oedema and ischaemic shaft ulcers. Removal of the graft was required in two patients in each group. Conclusion This pilot study shows that Pelvicol is not an ideal option for enhancing penile girth, and the method of placement did not apparently influence the result. PMID:26558077

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

    NASA Astrophysics Data System (ADS)

    Geng, Hongquan; Song, Hua; Qi, Jun; Cui, Daxiang

    2011-12-01

    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.

  4. 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

  5. Clinical Outcomes for Breast Cancer Patients Undergoing Mastectomy and Reconstruction with Use of DermACELL, a Sterile, Room Temperature Acellular Dermal Matrix

    PubMed Central

    Vashi, Christopher

    2014-01-01

    Background. Decellularized human skin has been used in a variety of medical applications, primarily involving soft tissue reconstruction, wound healing, and tendon augmentation. Theoretically, decellularization removes potentially immunogenic material and provides a clean scaffold for cellular and vascular in growth. The use of acellular dermal matrix in two-stage postmastectomy breast reconstruction is described. Methods. Ten consecutive breast cancer patients were treated with mastectomies and immediate reconstruction from August to November 2011. There were 8 bilateral and 1 unilateral mastectomies for a total of 17 breasts, with one exclusion for chronic tobacco use. Reconstruction included the use of a new 6 × 16 cm sterile, room temperature acellular dermal matrix patch (DermACELL) soaked in a cefazolin bath. Results. Of the 17 breasts, 15 reconstructions were completed; 14 of them with expander to implant sequence and acellular dermal matrix. Histological analysis of biopsies obtained during trimming of the matrix at the second stage appeared nonremarkable with evidence of normal healing, cellularity, and vascular infiltration. Conclusion. Postoperative observations showed that this cellular dermal matrix appears to be an appropriate adjunct to reconstruction with expanders. This acellular dermal matrix appeared to work well with all patients, even those receiving postoperative chemotherapy, postoperative radiation, prednisone, or warfarin sodium. PMID:24738030

  6. 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

  7. 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

  8. 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

  9. 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

  10. Repair of peripheral nerve defects with chemically extracted acellular nerve allografts loaded with neurotrophic factors-transfected bone marrow mesenchymal stem cells.

    PubMed

    Zhang, Yan-Ru; Ka, Ka; Zhang, Ge-Chen; Zhang, Hui; Shang, Yan; Zhao, Guo-Qiang; Huang, Wen-Hua

    2015-09-01

    Chemically extracted acellular nerve allografts loaded with brain-derived neurotrophic factor-transfected or ciliary neurotrophic factor-transfected bone marrow mesenchymal stem cells have been shown to repair sciatic nerve injury better than chemically extracted acellular nerve allografts alone, or chemically extracted acellular nerve allografts loaded with bone marrow mesenchymal stem cells. We hypothesized that these allografts compounded with both brain-derived neurotrophic factor- and ciliary neurotrophic factor-transfected bone marrow mesenchymal stem cells may demonstrate even better effects in the repair of peripheral nerve injury. We cultured bone marrow mesenchymal stem cells expressing brain-derived neurotrophic factor and/or ciliary neurotrophic factor and used them to treat sciatic nerve injury in rats. We observed an increase in sciatic functional index, triceps wet weight recovery rate, myelin thickness, number of myelinated nerve fibers, amplitude of motor-evoked potentials and nerve conduction velocity, and a shortened latency of motor-evoked potentials when allografts loaded with both neurotrophic factors were used, compared with allografts loaded with just one factor. Thus, the combination of both brain-derived neurotrophic factor and ciliary neurotrophic factor-transfected bone marrow mesenchymal stem cells can greatly improve nerve injury. PMID:26604913

  11. Repair of peripheral nerve defects with chemically extracted acellular nerve allografts loaded with neurotrophic factors-transfected bone marrow mesenchymal stem cells

    PubMed Central

    Zhang, Yan-ru; Ka, Ka; Zhang, Ge-chen; Zhang, Hui; Shang, Yan; Zhao, Guo-qiang; Huang, Wen-hua

    2015-01-01

    Chemically extracted acellular nerve allografts loaded with brain-derived neurotrophic factor-transfected or ciliary neurotrophic factor-transfected bone marrow mesenchymal stem cells have been shown to repair sciatic nerve injury better than chemically extracted acellular nerve allografts alone, or chemically extracted acellular nerve allografts loaded with bone marrow mesenchymal stem cells. We hypothesized that these allografts compounded with both brain-derived neurotrophic factor- and ciliary neurotrophic factor-transfected bone marrow mesenchymal stem cells may demonstrate even better effects in the repair of peripheral nerve injury. We cultured bone marrow mesenchymal stem cells expressing brain-derived neurotrophic factor and/or ciliary neurotrophic factor and used them to treat sciatic nerve injury in rats. We observed an increase in sciatic functional index, triceps wet weight recovery rate, myelin thickness, number of myelinated nerve fibers, amplitude of motor-evoked potentials and nerve conduction velocity, and a shortened latency of motor-evoked potentials when allografts loaded with both neurotrophic factors were used, compared with allografts loaded with just one factor. Thus, the combination of both brain-derived neurotrophic factor and ciliary neurotrophic factor-transfected bone marrow mesenchymal stem cells can greatly improve nerve injury. PMID:26604913

  12. Human keratinocyte growth and differentiation on acellular porcine dermal matrix in relation to wound healing potential.

    PubMed

    Zajicek, Robert; Mandys, Vaclav; Mestak, Ondrej; Sevcik, Jan; Königova, Radana; Matouskova, Eva

    2012-01-01

    A number of implantable biomaterials derived from animal tissues are now used in modern surgery. Xe-Derma is a dry, sterile, acellular porcine dermis. It has a remarkable healing effect on burns and other wounds. Our hypothesis was that the natural biological structure of Xe-Derma plays an important role in keratinocyte proliferation and formation of epidermal architecture in vitro as well as in vivo. The bioactivity of Xe-Derma was studied by a cell culture assay. We analyzed growth and differentiation of human keratinocytes cultured in vitro on Xe-Derma, and we compared the results with formation of neoepidermis in the deep dermal wounds treated with Xe-Derma. Keratinocytes cultured on Xe-Derma submerged in the culture medium achieved confluence in 7-10 days. After lifting the cultures to the air-liquid interface, the keratinocytes were stratified and differentiated within one week, forming an epidermis with basal, spinous, granular, and stratum corneum layers. Immunohistochemical detection of high-molecular weight cytokeratins (HMW CKs), CD29, p63, and involucrin confirmed the similarity of organization and differentiation of the cultured epidermal cells to the normal epidermis. The results suggest that the firm natural structure of Xe-Derma stimulates proliferation and differentiation of human primary keratinocytes and by this way improves wound healing. PMID:22629190

  13. 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

  14. 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

  15. 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.

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

    PubMed

    Rose, Jessica F; Zafar, Sarosh N; Ellsworth Iv, Warren A

    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

  17. Acellular Dermal Matrix in Reconstructive Breast Surgery: Survey of Current Practice among Plastic Surgeons

    PubMed Central

    Ibrahim, Ahmed M. S.; Koolen, Pieter G. L.; Ashraf, Azra A.; Kim, Kuylhee; Mureau, Marc A. M.; Lee, Bernard T.

    2015-01-01

    Background: Acellular dermal matrices (ADMs) in plastic surgery have become increasingly popular particularly for breast reconstruction. Despite their advantages, questions exist regarding their association with a possible increased incidence of complications. We describe a collective experience of plastic surgeons’ use of ADMs in reconstructive breast surgery using an internet-based survey. Methods: Members of the American Society of Plastic Surgeons were recruited through voluntary, anonymous participation in an online survey. The web-based survey garnered information about participant demographics and their experience with ADM use in breast reconstruction procedures. After responses were collected, all data were anonymously processed. Results: Data were ascertained through 365 physician responses of which 99% (n = 361) completed the survey. The majority of participants were men (84.5%) between 51 and 60 years (37.4%); 84.2% used ADM in breast reconstruction, including radiated patients (79.7%). ADM use was not favored for nipple reconstruction (81.5%); 94.6% of participants used drains, and 87.8% administered antibiotics postoperatively. The most common complications were seroma (70.9%) and infection (16%), although 57.4% claimed anecdotally that overall complication rate was unchanged after incorporating ADM into their practice. High cost was a deterrent for ADM use (37.5%). Conclusions: Plastic surgeons currently use ADM in breast reconstruction for both immediate and staged procedures. Of those responding, a majority of plastic surgeons will incorporate drains and use postoperative antibiotics for more than 48 hours. PMID:25973359

  18. Complex ventral hernia repair with a human acellular dermal matrix and component separation: A case series

    PubMed Central

    Garcia, Alvaro; Baldoni, Anthony

    2015-01-01

    We present a case series of 19 patients requiring complex abdominal hernia repairs. Patients presented with challenging clinical histories with 95% having multiple significant comorbidities including overweight or obesity (84%), hypertension (53%), diabetes (42%), cancer (26%), and pulmonary disease (16%). The majority of patients (68%) had prior abdominal infections and 53% had at least one failed prior hernia repair. Upon examination, fascial defects averaged 282 cm2. Anterior and posterior component separation was performed with placement of a human acellular dermal mesh. Midline abdominal closure under minimal tension was achieved primarily in all cases. Post-operative complications included 2 adverse events (11%) – one pulmonary embolism and one post-operative hemorrhage requiring transfusion; 6 wound-related complications (32%), 1 seroma (5%) and 1 patient with post-operative ileus (5%). Operative intervention was not required in any of the cases and most patients made an uneventful recovery. Increased patient age and longer OR time were independently predictive of early post-operative complications. At a median 2-year follow-up, three patients had a documented hernia recurrence (16%) and one patient was deceased due to unrelated causes. Conclusion Patients at high risk for post-operative events due to comorbidities, prior abdominal infection and failed mesh repairs do well following component separation reinforced with a human bioprosthetic mesh. Anticipated post-operative complications were managed conservatively and at a median 2-year follow-up, a low rate of hernia recurrence was observed with this approach. PMID:26288732

  19. Evaluating the Effectiveness of Cryopreserved Acellular Dermal Matrix in Immediate Expander-Based Breast Reconstruction: A Comparison Study

    PubMed Central

    Kim, So-Young; Lim, So Young; Mun, Goo-Hyun; Bang, Sa-Ik; Oh, Kap Sung

    2015-01-01

    Background CGCryoDerm was first introduced in 2010 and offers a different matrix preservation processes for freezing without drying preparation. From a theoretical perspective, CGCryoDerm has a more preserved dermal structure and more abundant growth factors for angiogenesis and recellularization. In the current study, the authors performed a retrospective study to evaluate freezing- and freeze-drying-processed acellular dermal matrix (ADM) to determine whether any differences were present in an early complication profile. Methods Patients who underwent ADM-assisted tissue expander placement for two stage breast reconstruction between January of 2013 and March of 2014 were retrospectively reviewed and divided into two groups based on the types of ADM-assisted expander reconstruction (CGDerm vs. CGCryoDerm). Complications were divided into four main categories and recorded as follows: seroma, hematoma, infection, and mastectomy skin flap necrosis. Results In a total of 82 consecutive patients, the CGCryoDerm group had lower rates of seroma when compared to the CGDerm group without statistical significance (3.0% vs. 10.2%, P=0.221), respectively. Other complications were similar in both groups. Reconstructions with CGCryoDerm were found to have a significantly longer period of drainage when compared to reconstructions with CGDerm (11.91 days vs. 10.41 days, P=0.043). Conclusions Preliminary findings indicate no significant differences in early complications between implant/expander-based reconstructions using CGCryoderm and those using CGDerm. PMID:26015887

  20. 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

  1. 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

  2. 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

  3. 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

  4. Ectopic bone formation in rapidly fabricated acellular injectable dense collagen-Bioglass hybrid scaffolds via gel aspiration-ejection.

    PubMed

    Miri, Amir K; Muja, Naser; Kamranpour, Neysan O; Lepry, William C; Boccaccini, Aldo R; Clarke, Susan A; Nazhat, Showan N

    2016-04-01

    Gel aspiration-ejection (GAE) has recently been introduced as an effective technique for the rapid production of injectable dense collagen (IDC) gel scaffolds with tunable collagen fibrillar densities (CFDs) and microstructures. Herein, a GAE system was applied for the advanced production and delivery of IDC and IDC-Bioglass(®) (IDC-BG) hybrid gel scaffolds for potential bone tissue engineering applications. The efficacy of GAE in generating mineralizable IDC-BG gels (from an initial 75-25 collagen-BG ratio) produced through needle gauge numbers 8G (3.4 mm diameter and 6 wt% CFD) and 14G (1.6 mm diameter and 14 wt% CFD) was investigated. Second harmonic generation (SHG) imaging of as-made gels revealed an increase in collagen fibril alignment with needle gauge number. In vitro mineralization of IDC-BG gels was confirmed where carbonated hydroxyapatite was detected as early as day 1 in simulated body fluid, which progressively increased up to day 14. In vivo mineralization of, and host response to, acellular IDC and IDC-BG gel scaffolds were further investigated following subcutaneous injection in adult rats. Mineralization, neovascularization and cell infiltration into the scaffolds was enhanced by the addition of BG and at day 21 post injection, there was evidence of remodelling of granulation tissue into woven bone-like tissue in IDC-BG. SHG imaging of explanted scaffolds indicated collagen fibril remodelling through cell infiltration and mineralization over time. In sum, the results suggest that IDC-BG hybrid gels have osteoinductive properties and potentially offer a novel therapeutic approach for procedures requiring the injectable delivery of a malleable and dynamic bone graft that mineralizes under physiological conditions. PMID:26871889

  5. 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

  6. Cellular versus acellular matrix devices in treatment of diabetic foot ulcers: study protocol for a comparative efficacy randomized controlled trial

    PubMed Central

    2013-01-01

    Background Diabetic foot ulcers (DFUs) represent a significant source of morbidity and an enormous financial burden. Standard care for DFUs involves systemic glucose control, ensuring adequate perfusion, debridement of nonviable tissue, off-loading, control of infection, local wound care and patient education, all administered by a multidisciplinary team. Unfortunately, even with the best standard of care (SOC) available, only 24% or 30% of DFUs will heal at weeks 12 or 20, respectively. The extracellular matrix (ECM) in DFUs is abnormal and its impairment has been proposed as a key target for new therapeutic devices. These devices intend to replace the aberrant ECM by implanting a matrix, either devoid of cells or enhanced with fibroblasts, keratinocytes or both as well as various growth factors. These new bioengineered skin substitutes are proposed to encourage angiogenesis and in-growth of new tissue, and to utilize living cells to generate cytokines needed for wound repair. To date, the efficacy of bioengineered ECM containing live cellular elements for improving healing above that of a SOC control group has not been compared with the efficacy of an ECM devoid of cells relative to the same SOC. Our hypothesis is that there is no difference in the improved healing effected by either of these two product types relative to SOC. Methods/Design To test this hypothesis we propose a randomized, single-blind, clinical trial with three arms: SOC, SOC plus Dermagraft® (bioengineered ECM containing living fibroblasts) and SOC plus Oasis® (ECM devoid of living cells) in patients with nonhealing DFUs. The primary outcome is the percentage of subjects that achieved complete wound closure by week 12. Discussion If our hypothesis is correct, then immense cost savings could be realized by using the orders-of-magnitude less expensive acellular ECM device without compromising patient health outcomes. The article describes the protocol proposed to test our hypothesis. Trial

  7. 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

  8. 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

  9. Root coverage using a coronally advanced flap with or without acellular dermal matrix: a meta-analysis

    PubMed Central

    2016-01-01

    Purpose Gingival recession is a major esthetic concern and may lead to root sensitivity during periodontal treatment. Coronally advanced flaps (CAFs) with and without acellular dermal matrix (ADM) are widely used in root coverage procedures. The aim of this study was to analyze the efficacy of CAF in combination with ADM in the treatment of gingival recession. Methods PubMed, The Cochrane Library, and Embase were used to identify relevant articles. The articles were screened, data were extracted, and the quality of the studies was assessed by three reviewers with expertise in clinical practice, trials, statistics, and biomedical editing. The clinical endpoints of interest included changes in recession, probing depth (PD), clinical attachment level (CAL), and keratinized tissue (KT). Results Ten randomized controlled trials were identified, including six studies that compared CAFs with ADM and CAFs using connective tissue grafting (CTG) and four studies that compared CAFs with or without ADM. No statistically significant differences were found between the use of ADM and CTG, whereas statistically significant differences were found between groups in which ADM and CAF were combined and groups that underwent CAF alone with regard to recession coverage, CAL, and KT. The combination of CAF with an ADM allograft achieved more favorable recession coverage and recovery of CAL and KT than CAF alone. Conclusions The results from the ADM and CTG groups suggest that both procedures may be equally effective in clinical practice. Given the limitations of this study, further investigation is needed to clarify the effectiveness of ADM and CAF in clinical practice. PMID:26937291

  10. Epithelial-differentiated adipose-derived stem cells seeded bladder acellular matrix grafts for urethral reconstruction: an animal model.

    PubMed

    Li, Hongbin; Xu, Yuemin; Xie, Hong; Li, Chao; Song, Lujie; Feng, Chao; Zhang, Qin; Xie, Minkai; Wang, Ying; Lv, Xiangguo

    2014-02-01

    The limited amount of available epithelial tissue is considered a main cause of the high rate of urethral reconstruction failures. The aim of this study was to investigate whether epithelial-differentiated rabbit adipose-derived stem cells (Epith-rASCs) could play a role of epithelium in vivo functionally and be a potential substitute of urothelium. Substitution urethroplasty was performed to repair an anterior urethral defect in male New Zealand rabbits using Epith-rASCs seeded bladder acellular matrix grafts (BAMGs) after 5-bromo-2'-deoxyuridine (BrdU) labeling, based on the in vitro epithelial induction system we previously described. Urethroplasty with cell-free BAMGs and with undifferentiated rASCs (Und-rASCs) seeded BAMGs were performed as controls. After surgery, a notable amelioration of graft contracture and recovery of urethral continuity were observed in the Epith-rASCs/BAMG group by retrograde urethrograms and macroscopic inspection. Immunofluorescence revealed that the BrdU-labeled Epith-rASCs/Und-rASCs colocalized with cytokeratin 13 or myosin. Consistent with the results of western blotting, at early postimplantation stage, the continuous epithelial layer with local multilayered structure was observed in the Epith-rASCs/BAMG group, whereas no significant growth and local monolayer growth profile of epithelial cells were observed in the BAMG and Und-rASCs/BAMG group, respectively. The results showed that Epith-rASCs could serve as a potential substitute of urothelium for urethral tissue engineering and be available to prevent lumen contracture and subsequent complications including recurrent stricture. PMID:24329501

  11. 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

  12. Unexpected soft tissue changes in response to root coverage using an acellular dermal matrix allograft: 12–year follow up.

    PubMed

    Batista, Eraldo L; Goergen, Josiane E; Machado, Larissa L; Santayana de Lima, Eduardo M

    2014-01-01

    A woman undergoing orthodontic treatment presented with recession and reduced keratinized gingiva on teeth 31 and 41. The patient declined creation of a donor site for conventional autogenous connective soft tissue grafting and opted for an acellular dermal matrix soft tissue substitute for root coverage. Orthodontic treatment followed, and the patient returned for orthognatic surgery after 12 years. Long-term follow up revealed that root coverage remained stable over time and creeping attachment on both teeth was observed. Unexpectedly, an increase in the width of keratinized gingiva was observed. No adverse effects of orthodontic treatment carried out after grafting were observed. PMID:25437945

  13. 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

  14. Dentin Matrix Proteins in Bone Tissue Engineering

    PubMed Central

    Ravindran, Sriram

    2016-01-01

    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. PMID:26545748

  15. 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

  16. 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

  17. 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

  18. 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

  19. Porcine incisional hernia model: Evaluation of biologically derived intact extracellular matrix repairs

    PubMed Central

    Delossantos, Aubrey I; Rodriguez, Neil L; Patel, Paarun; Franz, Michael G; Wagner, Christopher T

    2013-01-01

    We compared fascial wounds repaired with non-cross-linked intact porcine-derived acellular dermal matrix versus primary closure in a large-animal hernia model. Incisional hernias were created in Yucatan pigs and repaired after 3 weeks via open technique with suture-only primary closure or intraperitoneally placed porcine-derived acellular dermal matrix. Progressive changes in mechanical and biological properties of porcine-derived acellular dermal matrix and repair sites were assessed. Porcine-derived acellular dermal matrix–repaired hernias of additional animals were evaluated 2 and 4 weeks post incision to assess porcine-derived acellular dermal matrix regenerative potential and biomechanical changes. Hernias repaired with primary closure showed substantially more scarring and bone hyperplasia along the incision line. Mechanical remodeling of porcine-derived acellular dermal matrix was noted over time. Porcine-derived acellular dermal matrix elastic modulus and ultimate tensile stress were similar to fascia at 6 weeks. The biology of porcine-derived acellular dermal matrix–reinforced animals was more similar to native abdominal wall versus that with primary closure. In this study, porcine-derived acellular dermal matrix–reinforced repairs provided more complete wound healing response compared with primary closure. PMID:24555008

  20. 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

  1. 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. PMID:16984575

  2. 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

  3. 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

  4. Human acellular dermal matrix allograft: A randomized, controlled human trial for the long-term evaluation of patients with extensive burns.

    PubMed

    Li, Xueyong; Meng, Xianghai; Wang, Xiaolin; Li, Yuejun; Li, Wangzhou; Lv, Xiaoxing; Xu, Xiaoli; Lei, Zhanjun; Li, Jinqing

    2015-06-01

    The potential of acellular dermal matrix (ADM) to improve cosmetic and functional outcomes has been demonstrated; however, there have been few clinical comparative studies assessing the long-term morphological, histological and functional changes after ADM placement. This study was designed to retrospectively evaluate the long-term outcomes of the cograft acellular dermal matrix with autologous thin split-thickness skin for the coverage of wounds in extensively burned patients. Thirty burn patients treated with a composite graft of ADM with autologous split-thickness skin from January 2007 to December 2009 were enrolled in this study. Another group of thirty patients who received only an autogenous split-thickness skin implant served as the control. Our study revealed that the collagen in the dermis treated with ADM were ordered, and the proportion of collagen III/I was much higher in the control group than in the ADM group. The basement membrane was prominent and continuous. Meanwhile, the VBSS (Vancouver Burn Skin Score) was used to evaluate skin quality, which shows a significant differences between the two group (P<0.001). Then the functional level was evaluated by the BI (Barthel Index), and the ADM group was much better than the control group (P=0.005). Based on these results, we concluded that the composite graft of ADM with autologous thin split-thickness skin was suitable for repairing the defects in functional areas after a burn. This technique might facilitate wound management with acceptable esthetic outcomes, good functional recovery and less scar hyperplasia at the donor site. PMID:25687834

  5. 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

  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. Decellularized kidney matrix for perfused bone engineering.

    PubMed

    Burgkart, Rainer; Tron, Alexandru; Prodinger, Peter; Culmes, Mihaela; Tuebel, Jutta; van Griensven, Martijn; Saldamli, Belma; Schmitt, Andreas

    2014-07-01

    The vascularization of tissue-engineered constructs is yet an unsolved problem. Here, recent work on the decellularization of whole organs has opened new perspectives on tissue engineering. However, existing decellularization protocols last several days and derived biomatrices have only been reseeded with cells from the same tissue origin or stem cells differentiating into these types of tissue. Within the present work, we demonstrate a novel standardized, time-efficient, and reproducible protocol for the decellularization of solid tissues to derive a ready to use biomatrix within only 5 h. Furthermore, we prove that biomatrices are usable as potential scaffolds for tissue engineering of vascularized tissues, even beyond tissue and maybe even species barriers. To prove this, we seeded human primary osteoblasts into a rat kidney bioscaffold. Here, seeded cells spread homogeneously within the matrix and proliferate under dynamic culture conditions. The cells do not only maintain their original phenotype within the matrix, they also show a strong metabolic activity and remodel the biomatrix toward a bone-like extracellular matrix. Thus, the decellularization technique has the ability to become a platform technology for tissue engineering. It potentially offers a universally applicable and easily producible scaffold that addresses the yet unsolved problem of vascularization. PMID:24164381

  8. Preserving the Posttrapeziectomy Space with a Human Acellular Dermal Matrix Spacer: A Pilot Case Series of Patients with Thumb Carpometacarpal Joint Arthritis

    PubMed Central

    Yao, Caroline A.; Ellis, Chandra V.; Cohen, Myles J.

    2013-01-01

    Background: Advanced thumb carpometacarpal arthritis is widely treated with trapeziectomy and tendon interposition despite donor-site morbidities. Trapeziectomy alone leaves a postresection space, leading to proximal metacarpal migration and scaphoid/trapezoid impingement. Prosthetic implants have been unsuccessful due to particulate debris, silicone synovitis, osteolysis, and migration. Recent studies have shown successful use of allograft for interposition material in the posttrapeziectomy space both in animal and human models. To obviate the need for autologous tissue, maintain thumb length, and reduce the risk of scaphoid impingement, the senior author developed an interposition arthroplasty technique using a spacer constructed from human acellular dermal matrix (HADM). Methods: Sixteen patients with Eaton stage III–IV thumb carpometacarpal osteoarthritis received the above procedure from the 2 senior authors. HADM was imbricated to fill the posttrapeziectomy space and secured to the volar capsule and metacarpal base. Pre- and postoperative trapezial space on radiograph, pain scores, and grip strength were recorded. Results: Six months postoperatively, radiographs showed an average joint space loss of 11%. Heights postoperatively were not significantly different from immediate postoperative heights (P ≥ 0.01). At 6 months, patients had improved pain and grip strength (P ≤ 0.01). No infections, foreign body reactions, or other complications occurred. Conclusions: HADM has been used extensively in other forms of reconstruction and has been shown to incorporate into surrounding tissues through neovascularization. Our early results illustrate that HADM can safely fill the dead space left by trapeziectomy. PMID:25289260

  9. Transplantation of human adipose-derived mesenchymal stem cells on a bladder acellular matrix for bladder regeneration in a canine model.

    PubMed

    Hou, Xianglin; Shi, Chunying; Chen, Wei; Chen, Bing; Jia, Weisheng; Guo, Yu; Ma, Chao; Ye, Gang; Kang, Jiuhong; Dai, Jianwu

    2016-01-01

    Tissue engineering brings new hope for the reconstruction of injured bladders. The aim of the present study was to evaluate human adipose-derived mesenchymal stem cells (hADSCs) combined with a bladder acellular matrix (BAM) for bladder regeneration. A BAM or BAM loaded with hADSCs (BAM/hADSCs) was used to repair partial cystectomy of the bladder in a canine model. 6 months after implantation, calculi and urine leakage were not found in either the BAM or BAM/hADSCs group by cystography. And compared to the BAM group, a significant increase of maximum bladder volume and bladder compliance was observed in the BAM/hADSCs group by urodynamics evaluation. Moreover, histological analysis showed that the BAM/hADSCs group could more effectively promote the regeneration of bladder smooth muscle and vascularization than the BAM group. These results demonstrated that a BAM/hADSCs could be an effective approach to promote bladder reconstruction with potential clinical applications. PMID:27173009

  10. 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

  11. 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. PMID:26921625

  12. 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. PMID:26851341

  13. Bone tissue remodeling and development: focus on matrix metalloproteinase functions.

    PubMed

    Paiva, Katiucia Batista Silva; Granjeiro, José Mauro

    2014-11-01

    Bone-forming cells originate from distinct embryological layers, mesoderm (axial and appendicular bones) and ectoderm (precursor of neural crest cells, which mainly form facial bones). These cells will develop bones by two principal mechanisms: intramembranous and endochondral ossification. In both cases, condensation of multipotent mesenchymal cells occurs, at the site of the future bone, which differentiate into bone and cartilage-forming cells. During long bone development, an initial cartilaginous template is formed and replaced by bone in a coordinated and refined program involving chondrocyte proliferation and maturation, vascular invasion, recruitment of adult stem cells and intense remodeling of cartilage and bone matrix. Matrix metalloproteinases (MMPs) are the most important enzymes for cleaving structural components of the extracellular matrix (ECM), as well as other non-ECM molecules in the ECM space, pericellular perimeter and intracellularly. Thus, the bioactive molecules generated act on several biological events, such as development, tissue remodeling and homeostasis. Since the discovery of collagenase in bone cells, more than half of the MMP members have been detected in bone tissues under both physiological and pathological conditions. Pivotal functions of MMPs during development and bone regeneration have been revealed by knockout mouse models, such as chondrocyte proliferation and differentiation, osteoclast recruitment and function, bone modeling, coupling of bone resorption and formation (bone remodeling), osteoblast recruitment and survival, angiogenesis, osteocyte viability and function (biomechanical properties); as such alterations in MMP function may alter bone quality. In this review, we look at the principal properties of MMPs and their inhibitors (TIMPs and RECK), provide an up-date on their known functions in bone development and remodeling and discuss their potential application to Bone Bioengineering. PMID:25157440

  14. 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

  15. Bone scaffold architecture modulates the development of mineralized bone matrix by human embryonic stem cells

    PubMed Central

    Marcos-Campos, Ivan; Marolt, Darja; Petridis, Petros; Bhumiratana, Sarindr; Schmidt, Daniel; Vunjak-Novakovic, Gordana

    2012-01-01

    Decellularized bone has been widely used as a scaffold for bone formation, due to its similarity to the native bone matrix and excellent osteoinductive and biomechanical properties. We have previously shown that human mesenchymal and embryonic stem cells form functional bone matrix on such scaffolds, without the use of growth factors. In this study, we focused on differences in bone matrix that exist even among identical harvesting sites, and the effects of the matrix architecture and mineral content on bone formation by human embryonic stem cells (hESC). Mesenchymal progenitors derived from hESCs were cultured for 5 weeks in decellularized bone scaffolds with three different densities: low (0.281 ± 0.018 mg/mm3), medium (0.434 ± 0.015 mg/mm3) and high (0.618 ± 0.027 mg/mm3). The medium-density group yielded highest densities of cells and newly assembled bone matrix, presumably due to the best balance between the transport of nutrients and metabolites to and from the cells, space for cell infiltration, surface for cell attachment and the mechanical strength of the scaffolds, all of which depend on the scaffold density. Bone mineral was beneficial for the higher expression of bone markers in cultured cells and more robust accumulation of the new bone matrix. PMID:22901965

  16. 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

  17. Acellular Lung Scaffolds Direct Differentiation of Endoderm to Functional Airway Epithelial Cells: Requirement of Matrix-Bound HS Proteoglycans

    PubMed Central

    Shojaie, Sharareh; Ermini, Leonardo; Ackerley, Cameron; Wang, Jinxia; Chin, Stephanie; Yeganeh, Behzad; Bilodeau, Mélanie; Sambi, Manpreet; Rogers, Ian; Rossant, Janet; Bear, Christine E.; Post, Martin

    2015-01-01

    Summary Efficient differentiation of pluripotent cells to proximal and distal lung epithelial cell populations remains a challenging task. The 3D extracellular matrix (ECM) scaffold is a key component that regulates the interaction of secreted factors with cells during development by often binding to and limiting their diffusion within local gradients. Here we examined the role of the lung ECM in differentiation of pluripotent cells in vitro and demonstrate the robust inductive capacity of the native lung matrix alone. Extended culture of stem cell-derived definitive endoderm on decellularized lung scaffolds in defined, serum-free medium resulted in differentiation into mature airway epithelia, complete with ciliated cells, club cells, and basal cells with morphological and functional similarities to native airways. Heparitinase I, but not chondroitinase ABC, treatment of scaffolds revealed that the differentiation achieved is dependent on heparan sulfate proteoglycans and its bound factors remaining on decellularized scaffolds. PMID:25660407

  18. 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

  19. 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

  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. 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

  2. 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. PMID:20042428

  3. 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

  4. Healing Rates in a Multicenter Assessment of a Sterile, Room Temperature, Acellular Dermal Matrix Versus Conventional Care Wound Management and an Active Comparator in the Treatment of Full-Thickness Diabetic Foot Ulcers

    PubMed Central

    Cazzell, Shawn; Pham, Hau; Vayser, Dean; Reyzelman, Alexander

    2016-01-01

    Objective: The purpose of this 16-week, multicenter, randomized, controlled trial was to assess the healed ulcer rate of a human acellular dermal matrix, DermACELL, compared with conventional care and a second acellular dermal matrix, Graftjacket, in the treatment of full-thickness diabetic foot ulcers. Methods: One hundred sixty-eight patients were randomized into DermACELL, conventional care, and Graftjacket treatment arms in a 2:2:1 ratio. Patients in the acellular dermal matrix groups received either 1 or 2 applications of the graft at the discretion of the investigator. Weekly follow-up visits were conducted until the ulcer healed or the endpoint was reached. Results: At 16 weeks, the DermACELL arm had a significantly higher proportion of completely healed ulcers than the conventional care arm (67.9% vs 48.1%; P = .0385) and a nonsignificantly higher proportion than the Graftjacket arm (67.9% vs 47.8%; P = .1149). The DermACELL arm also exhibited a greater average percent reduction in wound area than the conventional care arm (91.4% vs 80.3%; P = .0791) and the Graftjacket arm (91.4% vs 73.5%; P = .0762). The proportion of severe adverse events and the proportion of overall early withdrawals were similar among the 3 groups based on relative population size (P ≥ .05). Conclusions: The results presented here indicate that DermACELL is an appropriate clinical option in the treatment of diabetic foot ulcers, with significant increases in healing rates and rate of percentage wound closure as compared with conventional care options. PMID:26933467

  5. 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

  6. 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

  7. 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.

  8. Impregnation of bone chips with alendronate and cefazolin, combined with demineralized bone matrix: a bone chamber study in goats

    PubMed Central

    2012-01-01

    Background Bone grafts from bone banks might be mixed with bisphosphonates to inhibit the osteoclastic response. This inhibition prevents the osteoclasts to resorb the allograft bone before new bone has been formed by the osteoblasts, which might prevent instability. Since bisphosphonates may not only inhibit osteoclasts, but also osteoblasts and thus bone formation, we studied different bisphosphonate concentrations combined with allograft bone. We investigated whether locally applied alendronate has an optimum dose with respect to bone resorption and formation. Further, we questioned whether the addition of demineralized bone matrix (DBM), would stimulate bone formation. Finally, we studied the effect of high levels of antibiotics on bone allograft healing, since mixing allograft bone with antibiotics might reduce the infection risk. Methods 25 goats received eight bone conduction chambers in the cortical bone of the proximal medial tibia. Five concentrations of alendronate (0, 0.5 mg/mL, 1 mg/mL, 2 mg/mL, and 10 mg/mL) were tested in combination with allograft bone and supplemented with cefazolin (200 μg/mL). Allograft not supplemented with alendronate and cefazolin served as control. In addition, allograft mixed with demineralized bone matrix, with and without alendronate, was tested. After 12 weeks, graft bone area and new bone area were determined with manual point counting. Results Graft resorption decreased significantly (p < 0.001) with increasing alendronate concentration. The area of new bone in the 1 mg/mL alendronate group was significantly (p = 0.002) higher when compared to the 10 mg/mL group. No differences could be observed between the group without alendronate, but with demineralized bone, and the control groups. Conclusions A dose-response relationship for local application of alendronate has been shown in this study. Most new bone was present at 1 mg/mL alendronate. Local application of cefazolin had no effect on bone remodelling. PMID:22443362

  9. Long-term in vitro degradation of PDLLA/bioglass bone scaffolds in acellular simulated body fluid.

    PubMed

    Blaker, J J; Nazhat, S N; Maquet, V; Boccaccini, A R

    2011-02-01

    The long-term (600days) in vitro degradation of highly porous poly(D,L-lactide) (PDLLA)/Bioglass-filled composite foams developed for bone tissue engineering scaffolds has been investigated in simulated body fluid (SBF). Foams of ∼93% porosity were produced by thermally induced phase separation (TIPS). The degradation profile for foams of neat PDLLA and the influence of Bioglass addition were comprehensively assessed in terms of changes in dimensional stability, pore morphology, weight loss, molecular weight and mechanical properties (dry and wet states). It is shown that the degradation process proceeded in several stages: (a) a quasi-stable stage, where water absorption and plasticization occurred together with weight loss due to Bioglass particle loss and dissolution, resulting in decreased wet mechanical properties; (b) a stage showing a slight increase in the wet mechanical properties and a moderate decrease in dimensions, with the properties remaining moderately constant until the onset of significant weight loss, whilst molecular weight continued to decrease; (c) an end stage of massive weight loss, disruption of the pore structure and the formation of blisters and embrittlement of the scaffold (evident on handling). The findings from this long-term in vitro degradation investigation underpin studies that have been and continue to be performed on highly porous poly(α-hydroxyesters) scaffolds filled with bioactive glasses for bone tissue engineering applications. PMID:20849987

  10. Coherent scattering and matrix correction in bone-lead measurements

    NASA Astrophysics Data System (ADS)

    Todd, A. C.

    2000-07-01

    The technique of K-shell x-ray fluorescence of lead in bone has been used in many studies of the health effects of lead. This paper addresses one aspect of the technique, namely the coherent conversion factor (CCF) which converts between the matrix of the calibration standards and those of human bone. The CCF is conventionally considered a constant but is a function of scattering angle, energy and the elemental composition of the matrices. The aims of this study were to quantify the effect on the CCF of several assumptions which may not have been tested adequately and to compare the CCFs for plaster of Paris (the present matrix of calibration standards) and a synthetic apatite matrix. The CCF was calculated, using relativistic form factors, for published compositions of bone, both assumed and assessed compositions of plaster, and the synthetic apatite. The main findings of the study were, first, that impurities in plaster, lead in the plaster or bone matrices, coherent scatter from non-bone tissues and the individual subject's measurement geometry are all minor or negligible effects; and, second, that the synthetic apatite matrix is more representative of bone mineral than is plaster of Paris.

  11. 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

  12. 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

  13. 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. PMID:25934278

  14. Alveolar Ridge Preservation Using Xenogeneic Collagen Matrix and Bone Allograft

    PubMed Central

    Parashis, Andreas O.; Kalaitzakis, Charalampos J.; Tatakis, Dimitris N.; Tosios, Konstantinos

    2014-01-01

    Alveolar ridge preservation (ARP) has been shown to prevent postextraction bone loss. The aim of this report is to highlight the clinical, radiographic, and histological outcomes following use of a bilayer xenogeneic collagen matrix (XCM) in combination with freeze-dried bone allograft (FDBA) for ARP. Nine patients were treated after extraction of 18 teeth. Following minimal flap elevation and atraumatic extraction, sockets were filled with FDBA. The XCM was adapted to cover the defect and 2-3 mm of adjacent bone and flaps were repositioned. Healing was uneventful in all cases, the XCM remained in place, and any matrix exposure was devoid of further complications. Exposed matrix portions were slowly vascularized and replaced by mature keratinized tissue within 2-3 months. Radiographic and clinical assessment indicated adequate volume of bone for implant placement, with all planned implants placed in acceptable positions. When fixed partial dentures were placed, restorations fulfilled aesthetic demands without requiring further augmentation procedures. Histological and immunohistochemical analysis from 9 sites (4 patients) indicated normal mucosa with complete incorporation of the matrix and absence of inflammatory response. The XCM + FDBA combination resulted in minimal complications and desirable soft and hard tissue therapeutic outcomes, suggesting the feasibility of this approach for ARP. PMID:25328523

  15. 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

  16. 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

  17. Attachment of osteocyte cell processes to the bone matrix

    PubMed Central

    McNamara, LM; Majeska, RJ; Weinbaum, S; Friedrich; Schaffler, MB

    2010-01-01

    In order for osteocytes to perceive mechanical information and regulate bone remodeling accordingly they must be anchored to their extracellular matrix (ECM). To date the nature of this attachment is not understood. Osteocytes are embedded in mineralized bone matrix, but maintain a pericellular space (50–80nm) to facilitate fluid flow and transport of metabolites. This provides a spatial limit for their attachment to bone matrix. Integrins are cell adhesion proteins that may play a role in osteocyte attachment. However, integrin attachments require proximity between the ECM, cell membrane and cytoskeleton, which conflicts with the osteocytes requirement for a pericellular fluid space. In this study we hypothesize that the challenge for osteocytes to attach to surrounding bone matrix, while also maintaining fluid-filled pericellular space, requires different “engineering” solutions than in other tissues that are not similarly constrained. Using novel rapid fixation techniques, to improve cell membrane and matrix protein preservation, and Transmission Electron Microscopy, the attachment of osteocyte processes to their canalicular boundaries are quantified. We report that the canalicular wall is wave-like with periodic conical protrusions extending into the pericellular space. By immunohistochemistry we identify that the integrin αvβ3 may play a role in attachment at these complexes; a punctate pattern of staining of β3 along the canalicular wall was consistent with observations of periodic protrusions extending into the pericellular space. We propose that during osteocyte attachment the pericellular space is periodically interrupted by underlying collagen fibrils that attach directly to the cell process membrane via integrin-attachments. PMID:19248169

  18. 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...

  19. Use of demineralized bone matrix in the extremities

    PubMed Central

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

    2015-01-01

    Autologous bone graft is considered as the gold standard for all indications for bone grafting procedures but the limited availability and complications in donor site resulted in seeking other options like allografts and bone graft substitutes. Demineralized bone matrix (DBM) is an allograft product with no quantity limitation. It is an osteoconductive material with osteoinductive capabilities, which vary among different products, depending on donor characteristics and differences in processing of the bone. The purpose of the present review is to provide a critical review of the existing literature concerning the use of DBM products in various procedures in the extremities. Clinical studies describing the use of DBM alone or in combination with other grafting material are available for only a few commercial products. The Level of Evidence of these studies and the resulting Grades of Recommendation are very low. In conclusion, further clinical studies of higher quality are required in order to improve the Recommendation Grades for or against the use of DBM products in bone grafting procedures. PMID:25793167

  20. BONE REGENERATION AFTER DEMINERALIZED BONE MATRIX AND CASTOR OIL (RICINUS COMMUNIS) POLYURETHANE IMPLANTATION

    PubMed Central

    Leite, Fábio Renato Manzolli; Ramalho, Lizeti Toledo de Oliveira

    2008-01-01

    Innocuous biocompatible materials have been searched to repair or reconstruct bone defects. Their goal is to restore the function of live or dead tissues. This study compared connective tissue and bone reaction when exposed to demineralized bovine bone matrix and a polyurethane resin derived from castor bean (Ricinus communis). Forty-five rats were assigned to 3 groups of 15 animals (control, bovine bone and polyurethane). A cylindrical defect was created on mandible base and filled with bovine bone matrix and the polyurethane. Control group received no treatment. Analyses were performed after 15, 45 and 60 days (5 animals each). Histological analysis revealed connective tissue tolerance to bovine bone with local inflammatory response similar to that of the control group. After 15 days, all groups demonstrated similar outcomes, with mild inflammatory reaction, probably due to the surgical procedure rather than to the material. In the polymer group, after 60 days, scarce multinucleated cells could still be observed. In general, all groups showed good stability and osteogenic connective tissue with blood vessels into the surgical area. The results suggest biocompatibility of both materials, seen by their integration into rat mandible. Moreover, the polyurethane seems to be an alternative in bone reconstruction and it is an inexhaustible source of biomaterial. PMID:19089203

  1. 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.

  2. 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. PMID:27012623

  3. The effect of carrier type on bone regeneration of demineralized bone matrix in vivo.

    PubMed

    Tavakol, Shima; Khoshzaban, Ahad; Azami, Mahmoud; Kashani, Iraj Ragerdi; Tavakol, Hani; Yazdanifar, Mahbube; Sorkhabadi, Seyed Mahdi Rezayat

    2013-11-01

    Demineralized bone matrix (DBM) is a bone substitute biomaterial used as an excellent grafting material. Some factors such as carrier type might affect the healing potential of this material. The background data discuss the present status of the field: Albumin as a main protein in blood and carboxymethyl cellulose (CMC) were applied frequently in the DBM gels. We investigated the bone-repairing properties of 2 DBMs with different carriers. Bone regeneration in 3 groups of rat calvaria treated with DBM from the Iranian Tissue Bank Research and Preparation Center, DBM from Hans Biomed Corporation, and an empty cavity was studied. Albumin and CMC as carriers were used. The results of bone regeneration in the samples after 1, 4, and 8 weeks of implantation were compared. The block of the histologic samples was stained with hematoxylin and eosin, and the percentage area of bone formation was calculated using the histomorphometry method. The results of in vivo tests showed a significantly stronger new regenerated bone occupation in the DBM with albumin carrier compared with the one with CMC 8 weeks after the implantation. The 2 types of DBM had a significant difference in bone regeneration. This difference is attributed to the type of carriers. Albumin could improve mineralization and bioactivity compared with CMC. PMID:24220423

  4. 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

  5. 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

  6. 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

  7. 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

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

    PubMed

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

    2014-04-01

    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

  9. 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

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

    PubMed

    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. Tissue engineering of bone: material and matrix considerations.

    PubMed

    Khan, Yusuf; Yaszemski, Michael J; Mikos, Antonios G; Laurencin, Cato T

    2008-02-01

    When the normal physiologic reaction to fracture does not occur, such as in fracture nonunions or large-scale traumatic bone injury, surgical intervention is warranted. Autografts and allografts represent current strategies for surgical intervention and subsequent bone repair, but each possesses limitations, such as donor-site morbidity with the use of autograft and the risk of disease transmission with the use of allograft. Synthetic bone-graft substitutes, developed in an effort to overcome the inherent limitations of autograft and allograft, represent an alternative strategy. These synthetic graft substitutes, or matrices, are formed from a variety of materials, including natural and synthetic polymers, ceramics, and composites, that are designed to mimic the three-dimensional characteristics of autograft tissue while maintaining viable cell populations. Matrices also act as delivery vehicles for factors, antibiotics, and chemotherapeutic agents, depending on the nature of the injury to be repaired. This intersection of matrices, cells, and therapeutic molecules has collectively been termed tissue engineering. Depending on the specific application of the matrix, certain materials may be more or less well suited to the final structure; these include polymers, ceramics, and composites of the two. Each category is represented by matrices that can form either solid preformed structures or injectable forms that harden in situ. This article discusses the myriad design considerations that are relevant to successful bone repair with tissue-engineered matrices and provides an overview of several manufacturing techniques that allow for the actualization of critical design parameters. PMID:18292355

  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. PMID:27367191

  14. 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

  15. Demineralized Bone Matrix Injection in Consolidation Phase Enhances Bone Regeneration in Distraction Osteogenesis via Endochondral Bone Formation

    PubMed Central

    Kim, Ji-Beom; Seo, Sang Gyo; Kim, Eo Jin; Kim, Ji Hye; Yoo, Won Joon; Cho, Tae-Joon; Choi, In Ho

    2015-01-01

    Background Distraction osteogenesis (DO) is a promising tool for bone and tissue regeneration. However, prolonged healing time remains a major problem. Various materials including cells, cytokines, and growth factors have been used in an attempt to enhance bone formation. We examined the effect of percutaneous injection of demineralized bone matrix (DBM) during the consolidation phase on bone regeneration after distraction. Methods The immature rabbit tibial DO model (20 mm length-gain) was used. Twenty-eight animals received DBM 100 mg percutaneously at the end of distraction. Another 22 animals were left without further procedure (control). Plain radiographs were taken every week. Postmortem bone dual-energy X-ray absorptiometry and micro-computed tomography (micro-CT) studies were performed at the third and sixth weeks of the consolidation period and histological analysis was performed. Results The regenerate bone mineral density was higher in the DBM group when compared with that in the saline injection control group at the third week postdistraction. Quantitative analysis using micro-CT revealed larger trabecular bone volume, higher trabecular number, and less trabecular separation in the DBM group than in the saline injection control group. Cross-sectional area and cortical thickness at the sixth week postdistraction, assessed using micro-CT, were greater in the regenerates of the DBM group compared with the control group. Histological evaluation revealed higher trabecular bone volume and trabecular number in the regenerate of the DBM group. New bone formation was apparently enhanced, via endochondral ossification, at the site and in the vicinity of the injected DBM. DBM was absorbed slowly, but it remained until the sixth postoperative week after injection. Conclusions DBM administration into the distraction gap at the end of the distraction period resulted in a significantly greater regenerate bone area, trabecular number, and cortical thickness in the

  16. Expression of bone matrix proteins in urolithiasis model rats.

    PubMed

    Yasui, T; Fujita, K; Sasaki, S; Sato, M; Sugimoto, M; Hirota, S; Kitamura, Y; Nomura, S; Kohri, K

    1999-08-01

    Urinary calcium stones are a pathological substance, and they show similarities to physiological mineralization and other pathological mineralizations. The expression of messenger (m) RNAs of osteopontin (OPN), matrix Gla protein (MGP), osteonectin (ON) and osteocalcin (OC) in bones and teeth has been described. We previously identified OPN as an important stone matrix protein. In addition, the spontaneous calcification of arteries and cartilage in mice lacking MGP was recently reported, a finding which indicates that MGP has a function as an inhibitor of mineralization. Here, we examined the mRNA expressions of OPN, MGP, ON, and OC in the kidneys of stone-forming model rats administered an oxalate precursor, ethylene glycol (EG) for up to 28 days. The Northern blotting showed that the mRNA expressions of OPN and MGP were markedly increased with the administration of EG, but their expression patterns differed. The OPN mRNA expression reached the maximal level at day 7 after the initiation of the EG treatment and showed no significant difference after 14 and 28 days, whereas the MGP mRNA expression rose gradually to day 28. The in situ hybridization demonstrated that the cell type expressing OPN mRNA was different from that expressing MGP. We suggest that OPN acts on calcification and MGP acts on suppression. PMID:10460895

  17. Influence of irradiation on the osteoinductive potential of demineralized bone matrix.

    PubMed

    Wientroub, S; Reddi, A H

    1988-04-01

    Samples of demineralized bone matrix (DBM) were exposed to graduated doses of radiation (1-15 Megarad) (Mrad) utilizing a linear accelerator and then implanted into the thoracic region of Long-Evans rats. Subcutaneous implantation of DBM into allogenic rats induces endochondral bone. In response to matrix implantation, a cascade of events ensues; mesenchymal cell proliferation on day 3 postimplantation, chondrogenesis on day 7, calcification of the cartilagenous matrix and chondrolysis on day 9, and osteogenesis on day 11 resulting in formation of an ossicle containing active hemopoietic tissue. Bone formation was assessed by measuring alkaline phosphatase activity, the rate of mineralization was determined by measuring 45Ca incorporation to bone mineral, and 40Ca content measured the extent of mineralization; acid phosphatase activity was used as a parameter for bone resorption. The dose of radiation (2.5 Mrad) currently used by bone banks for sterilization of bone tissue did not destroy the bone induction properties of DBM. Furthermore, radiation of 3-5 Mrad even enhanced bone induction, insofar as it produced more bone at the same interval of time than was obtained from unirradiated control samples. None of the radiation doses used in these experiments abolished bone induction, although the response induced by matrix irradiated with doses higher than 5 Mrad was delayed. PMID:3135091

  18. 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. PMID:24755526

  19. 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

  20. 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.

  1. 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.

  2. 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. PMID:26472048

  3. 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

  4. Safety and efficacy of use of demineralised bone matrix in orthopaedic and trauma surgery.

    PubMed

    Dinopoulos, Haralampos T H; Giannoudis, Peter V

    2006-11-01

    Demineralised bone matrix (DBM) acts as an osteoconductive, and possibly as an osteoinductive, material. It is widely used in orthopaedic, neurosurgical, plastic and dental areas. More than 500,000 bone grafting procedures with DBM are performed annually in the US. It does not offer structural support, but it is well suited for filling bone defects and cavities. The osteoinductive nature of DBM is presumably attributed to the presence of matrix-associated bone morphogenetic proteins (BMPs) and growth factors, which are made available to the host environment by the demineralisation process. Clinical results have not been uniformly favourable; however, a variable clinical response is attributed partly to nonuniform processing methods found among numerous bone banks and commercial suppliers. DBMs remain reasonably safe and effective products. The ultimate safe bone-graft substitute, one that is osteoconductive, osteoinductive, osteogenic and mechanically strong, remains elusive. PMID:17044811

  5. 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

  6. Demineralized Bone Matrix, as a Graft Enhancer of Auto-Local Bone in Posterior Lumbar Interbody Fusion

    PubMed Central

    Moon, Sang Ho; Kim, Tae Woo; Boo, Kyung Hwan; Hong, Sung Won

    2014-01-01

    Study Design A case controlled study with prospective data collection. Purpose To evaluate the early influence and the final consequence of demineralized bone matrix (DBM) on auto-local bone as a graft enhancer in posterior lumbar interbody fusion (PLIF). Overview of Literature DBM is known as an osteoinductive material; however, it has not been clearly recognized to enhance auto-local bone with a small amount. Methods Patients who had a PLIF were allocated into two groups. Group I (70 cases) used auto-local bone chips and group II (44 cases) used DBM as an additive to auto-local bone, 1 mL per a segment. Group selection was alternated. Early assessment was performed by computed tomography at 6 months and final assessment was done by simple radiography after 24 months at least. The degree of bone formation was assessed by 4 grade scale. Results The subjects of both groups were homogenous and had similar Oswestry Disability Index at final assessment. The ratio of auto-local bone chips and DBM was 6:1. The degree of bone formation at 6 months after surgery was superior in group II. However, there was no significant difference between the two groups at the final assessment. Conclusions DBM was not recognized to enhance auto-local bone with small amount. PMID:24761193

  7. Influence of whole body irradiation and local shielding on matrix-induced endochondral bone differentiation.

    PubMed

    Wientroub, S; Weiss, J F; Catravas, G N; Reddi, A H

    1990-01-01

    Subcutaneous implantation of demineralized bone matrix into allogeneic rats induces endochondral bone formation. We have investigated the effects of irradiation on the sequelae of the interaction of collagenous matrix and mesenchymal cells and on cartilage and bone differentiation. Rats were irradiated in a vertical direction with a midline dose of 850 rad. Radiation entered the rats ventrally while a small area of the upper thorax was locally shielded. After irradiation, bone matrix was implanted in shielded and nonshielded sites, and the implants were studied at various stages. On day 3, [3H]thymidine incorporation, an index of cell proliferation, was inhibited by 70% in the nonshielded sites compared to nonirradiated control rats. The degree of inhibition (35%) was less pronounced in shielded sites. Furthermore, there was recovery of cell proliferation in the shielded sites as opposed to the nonshielded contralateral site. A similar pattern was observed on day 7 as assessed by 35SO4 incorporation into proteoglycans during chondrogenesis. Bone formation and mineralization were quantified on day 11 by alkaline phosphatase activity and 45Ca incorporation. In nonshielded sites, there was a 73% inhibition of alkaline phosphatase activity. In conclusion, radiation impaired progenitor cell proliferation which resulted in decreased cartilage and bone differentiation. These findings imply that local mesenchymal cells proliferate and differentiate into bone in response to implanted collagenous matrix. PMID:2104773

  8. Remineralization of demineralized bone matrix (DBM) via alternating solution immersion (ASI).

    PubMed

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

    2013-10-01

    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

  9. Coagulation of blood plasma of guinea pig by the bone matrix.

    PubMed

    Huggins, C B; Reddi, A H

    1973-03-01

    Optimal amounts of demineralized bone matrix possess the ability to coagulate platelet-free heparinized, citrated, and oxalated blood plasmas of guinea pigs. Clotting constituents become denatured in contact with the insoluble coagulant proteins. Quantities in excess of optimal modify plasma so that it does not gel when thrombin is added. The newly described coagulant effects are not restricted to the bone matrix, but are present also in the demineralized matrices of tooth and ivory, and in denatured tendon as well. They are regulated properties that were not demonstrated in mineralized bone or native tendon. The coagulant attributes of bone matrix are consistent with those of electropositive polymers of a specific sort. PMID:4515003

  10. Design of an Osteoinductive Extracellular Fibronectin Matrix Protein for Bone Tissue Engineering

    PubMed Central

    Lee, Sujin; Lee, Dong-Sung; Choi, Ilsan; Pham, Le B. Hang; Jang, Jun-Hyeog

    2015-01-01

    Integrin-mediated cell-matrix interactions play an important role in osteogenesis. Here, we constructed a novel osteoinductive fibronectin matrix protein (oFN) for bone tissue engineering, designed to combine the integrin-binding modules from fibronectin (iFN) and a strong osteoinductive growth factor, bone morphogenetic protein-2. Compared with iFN, the purified oFN matrix protein caused a significant increase in cell adhesion and osteogenic differentiation of pre-osteoblast MC3T3-E1 cells (p < 0.05). PMID:25853265

  11. Bone Regeneration Using Dentin Matrix Depends on the Degree of Demineralization and Particle Size

    PubMed Central

    Koga, Takamitsu; Minamizato, Tokutaro; Kawai, Yosuke; Miura, Kei-ichiro; I, Takashi; Nakatani, Yuya; Sumita, Yoshinori; Asahina, Izumi

    2016-01-01

    Objectives This study aimed to examine the influence of particle size and extent of demineralization of dentin matrix on bone regeneration. Materials and Methods Extracted human teeth were pulverized and divided into 3 groups according to particle size; 200, 500, and 1000 μm. Each group was divided into 3 groups depending on the extent of demineralization; undemineralized dentin (UDD), partially demineralized dentin matrix (PDDM), and completely demineralized dentin matrix (CDDM). The dentin sample was implanted into rat calvarial bone defects. After 4 and 8 weeks, the bone regeneration was evaluated with micro-CT images, histomorphometric and immunohistochemical analyses. Osteoblasts were cultured on UDD and DDM to evaluate the cell attachment using electron microscope. Results Micro-CT images and histological observation revealed that CDDM had largely resorbed but UDD had not, and both of them induced little bone formation, whereas all particle sizes of PDDM induced more new bone, especially the 1000 μm. Electron microscopic observation showed osteoblasts attached to DDM but not to UDD. Conclusions PDDM with larger particle size induced prominent bone regeneration, probably because PDDM possessed a suitable surface for cell attachment. There might be an exquisite balance between its resorption and bone formation on it. PDDM could be considered as a potential bone substitute. PMID:26795024

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

    PubMed Central

    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. PMID:25452771

  13. IN SITU ACCUMULATION OF ADVANCED GLYCATION ENDPRODUCTS (AGES) IN BONE MATRIX AND ITS CORRELATION WITH OSTEOCLASTIC BONE RESORPTION

    PubMed Central

    Dong, X. Neil; Qin, An; Xu, Jiake; Wang, Xiaodu

    2011-01-01

    Advanced glycation end products (AGEs) have been observed to accumulate in bone with increasing age and may impose effects on bone resorption activities. However, the underlying mechanism of AGEs accumulation in bone is still poorly understood. In this study, human cortical bone specimens from young (31±6 years old), middle-aged (51±3 years old) and elderly (76±4 years old) groups were examined to determine the spatial-temporal distribution of AGEs in bone matrix and its effect on bone resorption activities by directly culturing osteoclastic cells on bone slices. The results of this study indicated that the fluorescence intensity (excitation wave length 360 nm and emission wave length 470±40 nm) could be used to estimate the relative distribution of AGEs in bone (pentosidine as its marker) under an epifluorescence microscope. Using the fluorescence intensity as the relative measure of AGEs concentration, it was found that the concentration of AGEs varied with biological tissue ages, showing the greatest amount in the interstitial tissue, followed by the old osteons, and the least amount in newly formed osteons. In addition, AGEs accumulation was found to be dependent on donor ages, suggesting that the younger the donor the less AGEs were accumulated in the tissue. Most interestingly, AGEs accumulation appeared to initiate from the region of cement lines, and spread diffusively to the other parts as the tissue aged. Finally, it was observed that the bone resorption activities of osteoclasts were positively correlated with the in situ concentration of AGEs and such an effect was enhanced with increasing donor age. These findings may help elucidate the mechanism of AGEs accumulation in bone and its association with bone remodeling process. PMID:21530698

  14. 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. PMID:25453948

  15. Functional analysis in vivo of engineered valved venous conduit with decellularized matrix and two bone marrow-derived progenitors in sheep.

    PubMed

    Yuan, Jian-Ming; Xiong, Shao-Hu; Liu, Zhen; Wen, Yu; Dang, Rui-Shan; Shen, Man-Ru; Zhang, Yong-Zhen; Zhang, Xi; Yang, Xiang-Qun; Zhang, Chuan-Sen

    2016-07-01

    Tissue engineering has been considered a promising approach for creating grafts to replace autologous venous valves. Here, ovine bone marrow-derived endothelial progenitor cells (EPCs) and multipotent adult progenitor cells (MAPCs) were harvested and then loaded into decellularized venous matrix to create tissue-engineered (TE) valved vein. Subsequently, the ovine femoral veins containing the valve were removed and replaced by TE grafts or acellular matrix only. The morphology and function were analysed for up to 1 year by ultrasonography, angiography, H&E staining and scanning electron microscopy (SEM). The differentiation of seeded cells was traced immunofluorochemically. The results showed that decellularized venous matrix could initially and feebly attract endogenous cells, but failed afterwards and were insufficient to restore valve function. On the contrary, the seeded cells differentiated into endothelial cells (ECs) in vivo and formed a monolayer endothelium, and smooth muscle cells within the scaffold therefore produced TE grafts comparable to the native vein valve. This TE graft remained patent and sufficient after implantation into the venous circuit of the ovine lower extremity for at least 6 months. Unfortunately, cells seeded on the luminal surface and both sides of the leaflets lost their biological functions at 12 months, resulting in thrombosis formation and leading to complete occlusion of the TE grafts and impotent venous valves. These findings suggest that this TE valved venous conduit can function physiologically in vivo in the medium term. Before translating this TE venous valve into clinical practice, the durability should be improved and thrombogenicity should be suppressed. Copyright © 2016 John Wiley & Sons, Ltd. PMID:23904287

  16. The use of demineralized bone matrix in the repair of segmental defects. Augmentation with extracted matrix proteins and a comparison with autologous grafts.

    PubMed

    Bolander, M E; Balian, G

    1986-10-01

    A soluble protein component of bone, bone morphogenetic protein, and decalcified bone matrix have been shown to induce the formation of bone in extraosseous tissue. Clinical and animal studies investigating the use of these materials as bone grafts have shown radiographic and histological evidence of formation of bone, but the clinical usefulness of these grafts remains unknown. This study compared the healing processes when plasma-coated demineralized bone matrix and autologous cancellous bone were used to graft segmental defects of bone. A standard procedure was used to make a two-centimeter defect bilaterally in the ulna of forty-eight skeletally mature New Zealand White rabbits. In each rabbit, one ulnar defect was grafted with autologous citrated plasma-coated demineralized bone matrix while the other defect served as a control and was grafted with either autologous cancellous bone from the iliac crest, demineralized bone matrix, or demineralized bone matrix augmented with bone proteins that had been extracted with guanidinium hydrochloride. The ulnar defect was stabilized by the intact radius, and no supplemental device was necessary for fixation. To examine spontaneous healing in this model, one group of rabbits had a control defect that was not grafted. The grafts were periodically evaluated by radiographs, and twelve weeks after surgery the grafts were harvested and tested to failure in a standard torsion-test machine. The mechanical parameters were calculated, and histological examination of major fragments of the grafts was performed. The results of the radiographic and histological evaluation showed that all of the grafted ulnae healed, with fusion of the graft to the cut ends of the defect and reformation of approximately normal anatomy. No ungrafted ulnar defects healed. The results from the mechanical tests were evaluated by comparing the defect that was grafted with plasma-coated demineralized bone matrix with the control graft in each animal. These

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

    PubMed

    Zhang, Jian; Lazarenko, Oxana P; Blackburn, Michael L; Badger, Thomas M; Ronis, Martin J J; Chen, Jin-Ran

    2013-06-01

    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-induced bone loss is associated with profound decreases in collagen 1 and Sirt1. This was accompanied by increases in expression and activity of the senescence marker collagenase and expression of p16/p21 in bone. Feeding a diet supplemented with blueberries (BB) to pre-pubertal rats throughout development or only prior to puberty [postnatal day 21 (PND21) to PND34] prevents OVX-induced effects on expression of these molecules at PND68. In order to provide more evidence and gain a better understanding on the association between bone collagen matrix and resident bone cell fate, in vitro studies on the cellular senescence pathway using primary calvarial cells and three cell lines (ST2 cells, OB6, and MLO-Y4) were conducted. We found that senescence was inhibited by collagen in a dose-response manner. Treatment of cells with serum from OVX rats accelerated osteoblastic cell senescence pathways, but serum from BB-fed OVX rats had no effect. In the presence of low collagen or treatment with OVX rat serum, ST2 cells exhibited higher potential to differentiate into adipocytes. Finally, we demonstrated that bone cell senescence is associated with decreased Sirt1 expression and activated p53, p16, and p21. These results suggest that (1) a significant prevention of OVX-induced bone cell senescence from adult rats can occur after only 14 days consumption of a BB-containing diet immediately prior to puberty, and (2) the molecular mechanisms underlying this effect involves, at least in part, prevention of collagen degradation. PMID:22555620

  18. 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

  19. 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

  20. Modifications in Bone Matrix of Estrogen-Deficient Rats Treated with Intermittent PTH

    PubMed Central

    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

  1. Comparison of the Human Bone Matrix Gelatin (HBMG) with Autogenous Bone Graft in Reconstruction of the Parietal Bone Defects in Rat: A Histological and Radiographic Study

    PubMed Central

    Shahoon, Hossein; Azimi, Hamid Reza; Kianbakht, Camellia

    2009-01-01

    Background and aims Autogenous bone graft is commonly used for reconstruction of bone defects in routine surgical procedures. The complexity of producing bone grafts and their application has lead to the use of human bone matrix gelatin (HBMG). The present study was conducted to compare the efficacy of HBMG and autograft on the reconstruction of bone defects in rats. Materials and methods In this cross-sectional, experimental study, two defects were put on left and right sides of parietal bone of rats. HBMG was placed randomly on defects of one side and autograft in the defects of the other side. All specimens were assessed and compared with each other according to histological and radiographic characteristics. Other assessments included amount and the rate of bone formation, inflammation signs, fibrosis tissue and cartilage formation and also radio-graphic characteristics of grafts, assessed by digital and film-based methods. Mann-Whitney U test was used for statistical analysis. Results The results showed a reduction of inflammation and an increase in new bone formation in both groups in 7, 14, 28 and 60 days after surgery. Bone formation with HBMG on day 24 was more than autograft. However, there was no sig-nificant difference between the groups on day 60. Superiority of digital method to film-based method of imaging was also observed. Conclusion Although HBMG has the same efficacy as autograft, the rate of bone reconstruction with HBMG is higher. HBMG also induces focal, rather than peripheral, bone construction in the defect. PMID:23230480

  2. Bone Matrix Composition Following PTH Treatment is Not Dependent on Sclerostin Status.

    PubMed

    Ross, Ryan D; Mashiatulla, Maleeha; Robling, Alexander G; Miller, Lisa M; Sumner, D Rick

    2016-02-01

    Sclerostin and parathyroid hormones are strong negative and positive regulators of bone formation, respectively. The anabolic response induced by intermittent (iPTH) treatment is sclerostin status-dependent. However, the interaction between sclerostin and iPTH at the matrix level is unknown. The goal of the current study was to determine if iPTH treatment affects matrix composition and, if so, whether these effects are dependent on sclerostin status. Humeral trabecular and cortical bone sites from 16 week old male wild-type (WT) and sclerostin knockout (KO) mice, which had been treated with vehicle or iPTH from age 10-16 weeks, were examined by micro-computed tomography (µCT) to measure bone volume, backscatter scanning electron microscopy (bSEM) to assess global mineralization, and Fourier transform infrared microspectroscopy (FTIRM) to examine matrix composition (mineral-to-matrix ratio, crystallinity, collagen cross-link ratio, and carbonate substitution). The FTIRM measurements were restricted to the tissue formed during the 6-week treatment period. iPTH treatment led to increased trabecular bone volume (p < 0.001) and this effect was much greater in KO mice than WT mice (interaction effect, p < 0.001). iPTH treatment led to reduced trabecular crystallinity (p = 0.047), increased cortical bone area (p < 0.001), decreased cortical bone crystallinity (p = 0.002) and increased cortical bone collagen cross-linking (p = 0.028) to similar degrees in both WT and KO mice. Compared to WT mice, sclerostin KO mice had higher trabecular and cortical bone mass (p < 0.001) and lower mineral-to-matrix ratio in the trabecular (p = 0.010) and cortical (p = 0.016) compartments. Thus, iPTH-induced changes in bone mass are dependent upon sclerostin status in the trabecular compartment, but not in the cortical compartment. In contrast, iPTH-induced changes in matrix composition are sclerostin-independent in both trabecular and cortical compartments. PMID:26514840

  3. 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). PMID:26762722

  4. 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

  5. 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

  6. 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.

  7. 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

  8. Serum albumin coating of demineralized bone matrix results in stronger new bone formation.

    PubMed

    Horváthy, Dénes B; Vácz, Gabriella; Szabó, Tamás; Szigyártó, Imola C; Toró, Ildikó; Vámos, Boglárka; Hornyák, István; Renner, Károly; Klára, Tamás; Szabó, Bence T; Dobó-Nagy, Csaba; Doros, Attila; Lacza, Zsombor

    2016-01-01

    Blood serum fractions are hotly debated adjuvants in bone replacement therapies. In the present experiment, we coated demineralized bone matrices (DBM) with serum albumin and investigated stem cell attachment in vitro and bone formation in a rat calvaria defect model. In the in vitro experiments, we observed that significantly more cells adhere to the serum albumin coated DBMs at every time point. In vivo bone formation with albumin coated and uncoated DBM was monitored biweekly by computed tomography until 11 weeks postoperatively while empty defects served as controls. By the seventh week, the bone defect in the albumin group was almost completely closed (remaining defect 3.0 ± 2.3%), while uncoated DBM and unfilled control groups still had significant defects (uncoated: 40.2 ± 9.1%, control: 52.4 ± 8.9%). Higher density values were also observed in the albumin coated DBM group. In addition, the serum albumin enhanced group showed significantly higher volume of newly formed bone in the microCT analysis and produced significantly higher breaking force and stiffness compared to the uncoated grafts (peak breaking force: uncoated: 15.7 ± 4 N, albumin 46.1 ± 11 N). In conclusion, this investigation shows that implanting serum albumin coated DBM significantly reduces healing period in nonhealing defects and results in mechanically stronger bone. These results also support the idea that serum albumin coating provides a convenient milieu for stem cell function, and a much improved bone grafting success can be achieved without the use of exogenous stem cells. PMID:25677203

  9. 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.

  10. 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

  11. 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

  12. Different matrix evaluation for the bone regeneration of rats' femours using time domain optical coherence tomography

    NASA Astrophysics Data System (ADS)

    Rusu, Laura-Cristina; Negrutiu, Meda Lavinia; Sinescu, Cosmin; Hoinoiu, Bogdan; Zaharia, Cristian; Ardelean, Lavinia; Duma, Virgil-Florin; Podoleanu, Adrian G.

    2014-01-01

    The osteoconductive materials are important in bone regeneration procedures. Three dimensional (3D) reconstructions were obtained from the analysis. The aim of this study 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 two artificial matrixes inserted in previously artificially induced defects. For this study, under strict supervision 20 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 IngeniOss (for ten samples) and 4Bone(for the other ten samples). These materials were inserted into the induced defects. The femurs were investigated at 1 month, after the surgical procedures. The interfaces were examined using Time Domain (TD) Optical Coherence Tomography (OCT) combined with Confocal Microscopy (CM). The scanning procedure is similar to that used in any CM, where the fast scanning is en-face (line rate) and the scanning in depth is much slower (at the frame rate). The optical configuration uses two single mode directional couplers with a superluminiscent diode as the source centered at 1300 nm. The results showed open interfaces due to the insufficient healing process, as well as closed interfaces due to a new bone formation inside the defect. The conclusion of this study is that TD-OCT can act as a valuable tool in the investigation of the interface between the old bone and the one that has been newly created due to the osteoinductive process. The TD-OCT has proven a valuable tool for the non-invasive evaluation of the matrix bone interfaces.

  13. Demineralized bone matrix and human cancellous bone enhance fixation of porous-coated titanium implants in sheep.

    PubMed

    Babiker, Hassan; Ding, Ming; Overgaard, Søren

    2016-03-01

    Allogenic bone graft has been considered the gold standard in connection with bone graft material in revision joint arthroplasty. However, the lack of osteogenic potential and the risk of disease transmission are clinical challenges. The use of osteoinductive materials, such as demineralized bone matrix (DBM), alone or in combination with allograft or commercially available human cancellous bone (CB), may replace allografts, as they have the capability of inducing new bone and improving implant fixation through enhancing bone ongrowth. The purpose of this study was to investigate the effect of DBM alone, DBM with CB, or allograft on the fixation of porous-coated titanium implants. DBM100 and CB produced from human tissue were included. Both materials are commercially available. DBM granules are placed in pure DBM and do not contain any other carrier. Titanium alloy implants, 10 mm long × 10 mm diameter, were inserted bilaterally into the femoral condyles of eight skeletally mature sheep. Thus, four implants with a concentric gap of 2 mm were implanted in each sheep. The gap was filled with: (a) DBM; (b) DBM:CB at a ratio of 1:3; (c) DBM:allograft at a ratio of 1:3; or (d) allograft (gold standard), respectively. A standardized surgical procedure was used. At sacrifice 6 weeks after implantation, both distal femurs were harvested. The implant fixation was evaluated by mechanical push-out testing to test shear mechanical properties between implant and the host bone and by histomorphometry. Non-parametric tests were applied; p < 0.05 was considered significant. Mechanical fixation showed that the strengths among the DBM/CB, DBM/allograft and allograft groups were not statistically different. The strength of the DBM group was 0.01 MPa, which was statistical significantly lower than the other three groups (p < 0.05). Histomorphometry results showed that the bone ongrowth in the DBM group was statistically significantly lower than the other three groups

  14. Chest wall reconstruction in a canine model using polydioxanone mesh, demineralized bone matrix and bone marrow stromal cells.

    PubMed

    Tang, Hua; Xu, Zhifei; Qin, Xiong; Wu, Bin; Wu, Lihui; Zhao, XueWei; Li, Yulin

    2009-07-01

    Extensive chest wall defect reconstruction remains a challenging problem for surgeons. In the past several years, little progress has been made in this area. In this study, a biodegradable polydioxanone (PDO) mesh and demineralized bone matrix (DBM) seeded with osteogenically induced bone marrow stromal cells (BMSCs) were used to reconstruct a 6 cm x 5.5 cm chest wall defect. Four experimental groups were evaluated (n=6 per group): polydioxanone (PDO) mesh/DBMs/BMSCs group, polydioxanone (PDO) mesh/DBMs group, polydioxanone (PDO) mesh group, and a blank group (no materials) in a canine model. All the animals survived except those in the blank group. In all groups receiving biomaterial implants, the polydioxanone (PDO) mesh completely degraded at 24 weeks and was replaced by fibrous tissue with thickness close to that of the normal intercostal tissue (P>0.05). In the polydioxanone (PDO) mesh/DBMs/BMSCs group, new bone formation and bone-union were observed by radiographic and histological examination. More importantly, the reconstructed rib could maintain its original radian and achieve satisfactory biomechanics close to normal ribs in terms of bending stress (P>0.05). However, in the other two groups, fibrous tissue was observed in the defect and junctions, and the reconstructed ribs were easily distorted under an outer force. Based on these results, a surgical approach utilizing biodegradable polydioxanone (PDO) mesh in combination with DBMs and BMSCs could repair the chest wall defect not only in function but also in structure. PMID:19233465

  15. Mechanisms of fluid-flow-induced matrix production in bone tissue engineering.

    PubMed

    Morris, H L; Reed, C I; Haycock, J W; Reilly, G C

    2010-12-01

    Matrix production by tissue-engineered bone is enhanced when the growing tissue is subjected to mechanical forces and/or fluid flow in bioreactor culture. Cells deposit collagen and mineral, depending upon the mechanical loading that they receive. However, the molecular mechanisms of flow-induced signal transduction in bone are poorly understood. The hyaluronan (HA) glycocalyx has been proposed as a potential mediator of mechanical forces in bone. Using a parallel-plate flow chamber the effects of removal of HA on flow-induced collagen production and NF-kappaB activation in MLO-A5 osteoid osteocytes were investigated. Short periods of fluid flow significantly increased collagen production and induced translocation of the NF-kappaB subunit p65 to the cell's nuclei in 65 per cent of the cell population. Enzymatic removal of the HA coat and antibody blocking of CD44 (a transmembrane protein that binds to HA) eliminated the fluid-flow-induced increase in collagen production but had no effect on the translocation of p65. HA and CD44 appear to play roles in transducing the flow signals that modulate collagen production over long-term culture but not in the short-term flow-induced activation of NF-kappaB, implying that multiple signalling events are initiated from the commencement of flow. Understanding the mechanotransduction events that enable fluid flow to stimulate bone matrix production will allow the optimization of bioreactor design and flow profiles for bone tissue engineering. PMID:21287834

  16. TIEG1-NULL OSTEOCYTES DISPLAY DEFECTS IN THEIR MORPHOLOGY, DENSITY AND SURROUNDING BONE MATRIX

    PubMed Central

    Haddad, Oualid; Hawse, John R.; Subramaniam, Malayannan; Spelsberg, Thomas C.; Bensamoun, Sabine F.

    2011-01-01

    Through the development of TGFβ-inducible early gene-1 (TIEG1) knockout (KO) mice, we have demonstrated that TIEG1 plays an important role in osteoblast-mediated bone mineralization, and in bone resistance to mechanical strain. To further investigate the influence of TIEG1 in skeletal maintenance, osteocytes were analyzed by transmission electron microscopy using TIEG1 KO and wild-type mouse femurs at one, three and eight months of age. The results revealed an age-dependent change in osteocyte surface and density, suggesting a role for TIEG1 in osteocyte development. Moreover, there was a decrease in the amount of hypomineralized bone matrix surrounding the osteocytes in TIEG1 KO mice relative to wild-type controls. While little is known about the function or importance of this hypomineralized bone matrix immediately adjacent to osteocytes, this study reveals significant differences in this bone microenvironment and suggests that osteocyte function may be compromised in the absence of TIEG1 expression. PMID:22121306

  17. 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

  18. Osteogenic Matrix Cell Sheet Transplantation Enhances Early Tendon Graft to Bone Tunnel Healing in Rabbits

    PubMed Central

    Uematsu, Kota; Akahane, Manabu; Morita, Yusuke; Ogawa, Munehiro; Ueha, Tomoyuki; Shimizu, Takamasa; Kura, Tomohiko; Kawate, Kenji; Tanaka, Yasuhito

    2013-01-01

    The objective of this study was to determine whether osteogenic matrix cell sheets (OMCS) could induce bone formation around grafted tendons, thereby enhancing early stage tendon to bone tunnel healing in skeletally mature male Japanese white rabbits. First, the osteogenic potential of rabbit OMCS was evaluated. Then, the OMCS were transplanted into the interface between the grafted tendon and the bone tunnel created at the tibia. Histological assessments and biomechanical tensile testing were performed after 3 weeks. The rabbit OMCS showed high alkaline phosphatase (ALP) activity, positive staining of ALP, and osteogenic potential when transplanted subcutaneously with beta tricalcium phosphate disks. Newly formed bony walls and positive collagen type I staining were seen around the grafted tendon with OMCS transplantation, whereas such bony walls were thinner or less frequent without OMCS transplantation. Micro-computed tomography images showed significantly higher bone volume in the OMCS transplantation group. The pullout strength was significantly higher with OMCS (0.74 ± 0.23 N/mm2) than without OMCS (0.58 ± 0.15 N/mm2). These results show that OMCS enhance early tendon to bone tunnel healing. This method can be applied to cases requiring early tendon to bone tunnel healing after ligament reconstruction surgery. PMID:24106718

  19. Development of biomimetic nanocomposites as bone extracellular matrix for human osteoblastic cells.

    PubMed

    Bhowmick, Arundhati; Mitra, Tapas; Gnanamani, Arumugam; Das, Manas; Kundu, Patit Paban

    2016-05-01

    Here, we have developed biomimetic nanocomposites containing chitosan, poly(vinyl alcohol) and nano-hydroxyapatite-zinc oxide as bone extracellular matrix for human osteoblastic cells and characterized by Fourier transform infrared spectroscopy, powder X-ray diffraction. Scanning electron microscopy images revealed interconnected macroporous structures. Moreover, in this study, the problem related to fabricating a porous composite with good mechanical strength has been resolved by incorporating 5wt% of nano-hydroxyapatite-zinc oxide into chitosan-poly(vinyl alcohol) matrix; the present composite showed high tensile strength (20.25MPa) while maintaining appreciable porosity (65.25%). These values are similar to human cancellous bone. These nanocomposites also showed superior water uptake, antimicrobial and biodegradable properties than the previously reported results. Compatibility with human blood and pH was observed, indicating nontoxicity of these materials to the human body. Moreover, proliferation of osteoblastic MG-63 cells onto the nanocomposites was also observed without having any negative effect. PMID:26876999

  20. Quantification of various growth factors in different demineralized bone matrix preparations.

    PubMed

    Wildemann, B; Kadow-Romacker, A; Haas, N P; Schmidmaier, G

    2007-05-01

    Besides autografts, allografts, and synthetic materials, demineralized bone matrix (DBM) is used for bone defect filling and treatment of non-unions. Different DBM formulations are introduced in clinic since years. However, little is known about the presents and quantities of growth factors in DBM. Aim of the present study was the quantification of eight growth factors important for bone healing in three different "off the shelf" DBM formulations, which are already in human use: DBX putty, Grafton DBM putty, and AlloMatrix putty. All three DBM formulations are produced from human donor tissue but they differ in the substitutes added. From each of the three products 10 different lots were analyzed. Protein was extracted from the samples with Guanidine HCL/EDTA method and human ELISA kits were used for growth factor quantification. Differences between the three different products were seen in total protein contend and the absolute growth factor values but also a large variability between the different lots was found. The order of the growth factors, however, is almost comparable between the materials. In the three investigated materials FGF basic and BMP-4 were not detectable in any analyzed sample. BMP-2 revealed the highest concentration extractable from the samples with approximately 3.6 microg/g tissue without a significant difference between the three DBM formulations. In DBX putty significantly more TGF-beta1 and FGFa were measurable compared to the two other DBMs. IGF-I revealed the significantly highest value in the AlloMatrix and PDGF in Grafton. No differences were accessed for VEGF. Due to the differences in the growth factor concentration between the individual samples, independently from the product formulation, further analyzes are required to optimize the clinical outcome of the used demineralized bone matrix. PMID:17117475

  1. Ameloblastin, an Extracellular Matrix Protein, Affects Long Bone Growth and Mineralization.

    PubMed

    Lu, Xuanyu; Fukumoto, Satoshi; Yamada, Yoshihiko; Evans, Carla A; Diekwisch, Thomas Gh; Luan, Xianghong

    2016-06-01

    Matrix molecules such as the enamel-related calcium-binding phosphoprotein ameloblastin (AMBN) are expressed in multiple tissues, including teeth, bones, and cartilage. Here we have asked whether AMBN is of functional importance for timely long bone development and, if so, how it exerts its function related to osteogenesis. Adolescent AMBN-deficient mice (AMBN(Δ5-6) ) suffered from a 33% to 38% reduction in femur length and an 8.4% shorter trunk spinal column when compared with WT controls, whereas there was no difference between adult animals. On a cellular level, AMBN truncation resulted in a shortened growth plate and a 41% to 49% reduction in the number of proliferating tibia chondrocytes and osteoblasts. Bone marrow stromal cells (BMSCs) isolated from AMBN mutant mice displayed defects in proliferation and differentiation potential as well as cytoskeleton organization. Osteogenesis-related growth factors, such as insulin-like growth factor 1 (IGF1) and BMP7, were also significantly (46% to 73%) reduced in AMBN-deficient BMSCs. Addition of exogenous AMBN restored cytoskeleton structures in AMBN mutant BMSCs and resulted in a dramatic 400% to 600% increase in BMP2, BMP7, and Col1A expression. Block of RhoA diminished the effect of AMBN on osteogenic growth factor and matrix protein gene expression. Addition of exogenous BMP7 and IGF1 rescued the proliferation and differentiation potential of AMBN-deficient BMSCs. Confirming the effects of AMBN on long bone growth, back-crossing of mutant mice with full-length AMBN overexpressors resulted in a complete rescue of AMBN(Δ5-6) bone defects. Together, these data indicate that AMBN affects extracellular matrix production and cell adhesion properties in the long bone growth plate, resulting in altered cytoskeletal dynamics, increased osteogenesis-related gene expression, as well as osteoblast and chondrocyte proliferation. We propose that AMBN facilitates rapid long bone growth and an important growth spurt during the

  2. Effects of the decellularization method on the local stiffness of acellular lungs.

    PubMed

    Melo, Esther; Garreta, Elena; Luque, Tomas; Cortiella, Joaquin; Nichols, Joan; Navajas, Daniel; Farré, Ramon

    2014-05-01

    Lung bioengineering, a novel approach to obtain organs potentially available for transplantation, is based on decellularizing donor lungs and seeding natural scaffolds with stem cells. Various physicochemical protocols have been used to decellularize lungs, and their performance has been evaluated in terms of efficient decellularization and matrix preservation. No data are available, however, on the effect of different decellularization procedures on the local stiffness of the acellular lung. This information is important since stem cells directly sense the rigidity of the local site they are engrafting to during recellularization, and it has been shown that substrate stiffness modulates cell fate into different phenotypes. The aim of this study was to assess the effects of the decellularization procedure on the inhomogeneous local stiffness of the acellular lung on five different sites: alveolar septa, alveolar junctions, pleura, and vessels' tunica intima and tunica adventitia. Local matrix stiffness was measured by computing Young's modulus with atomic force microscopy after decellularizing the lungs of 36 healthy rats (Sprague-Dawley, male, 250-300 g) with four different protocols with/without perfusion through the lung circulatory system and using two different detergents (sodium dodecyl sulfate [SDS] and 3-[(3-cholamidopropyl) dimethylammonio]-1-propanesulfonate [CHAPS]). The local stiffness of the acellular lung matrix significantly depended on the site within the matrix (p<0.001), ranging from ∼ 15 kPa at the alveolar septum to ∼ 60 kPa at the tunica intima. Acellular lung stiffness (p=0.003) depended significantly, albeit modestly, on the decellularization process. Whereas perfusion did not induce any significant differences in stiffness, the use of CHAPS resulted in a ∼ 35% reduction compared with SDS, the influence of the detergent being more important in the tunica intima. In conclusion, lung matrix stiffness is considerably inhomogeneous, and

  3. 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.

  4. 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.

  5. 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

  6. Biological conduits combining bone marrow mesenchymal stem cells and extracellular matrix to treat long-segment sciatic nerve defects

    PubMed Central

    Wang, Yang; Li, Zheng-wei; Luo, Min; Li, Ya-jun; Zhang, Ke-qiang

    2015-01-01

    The transplantation of polylactic glycolic acid conduits combining bone marrow mesenchymal stem cells and extracellular matrix gel for the repair of sciatic nerve injury is effective in some respects, but few data comparing the biomechanical factors related to the sciatic nerve are available. In the present study, rabbit models of 10-mm sciatic nerve defects were prepared. The rabbit models were repaired with autologous nerve, a polylactic glycolic acid conduit + bone marrow mesenchymal stem cells, or a polylactic glycolic acid conduit + bone marrow mesenchymal stem cells + extracellular matrix gel. After 24 weeks, mechanical testing was performed to determine the stress relaxation and creep parameters. Following sciatic nerve injury, the magnitudes of the stress decrease and strain increase at 7,200 seconds were largest in the polylactic glycolic acid conduit + bone marrow mesenchymal stem cells + extracellular matrix gel group, followed by the polylactic glycolic acid conduit + bone marrow mesenchymal stem cells group, and then the autologous nerve group. Hematoxylin-eosin staining demonstrated that compared with the polylactic glycolic acid conduit + bone marrow mesenchymal stem cells group and the autologous nerve group, a more complete sciatic nerve regeneration was found, including good myelination, regularly arranged nerve fibers, and a completely degraded and resorbed conduit, in the polylactic glycolic acid conduit + bone marrow mesenchymal stem cells + extracellular matrix gel group. These results indicate that bridging 10-mm sciatic nerve defects with a polylactic glycolic acid conduit + bone marrow mesenchymal stem cells + extracellular matrix gel construct increases the stress relaxation under a constant strain, reducing anastomotic tension. Large elongations under a constant physiological load can limit the anastomotic opening and shift, which is beneficial for the regeneration and functional reconstruction of sciatic nerve. Better regeneration was

  7. 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

  8. Effectiveness of Posterolateral Lumbar Fusion Varies with the Physical Properties of Demineralized Bone Matrix Strip

    PubMed Central

    Kim, Dae-Hee; Park, Ji-Hun; Johnstone, Brian; Yoo, Jung-U

    2015-01-01

    Study Design A randomized, controlled animal study. Purpose To investigate the effectiveness of fusion and new bone formation induced by demineralized bone matrix (DBM) strips with jelly strengths. Overview of Literature The form of the DBM can make a difference to the outcome. The effect of different jelly strengths on the ability of DBM to form new bone is not known. Methods Forty-eight rabbits were randomized into a control group and two experimental groups. In the control group (group 1), 1.4 g of autologous iliac crest bone was placed bilaterally. In the experimental groups, a high jelly strength DBM-hyaluronic acid (HA)-gelatin strip (group 2) and a low jelly strength DBM-HA-gelatin strip (group 3) were used. The fusion was assessed with manual manipulation and radiographs. The volume of the fusion mass was determined from computed tomographic images. Results The fusion rates as determined by manual palpation were 37.5%, 93.8% and 50.0% in group 1, group 2, and group 3, respectively (p<0.05). By radiography, the fusion rate of High jelly strength DBM strip was statistically significantly greater than that of the other alternatives (p<0.05). The mean bone volume of the fusion mass as determined by computed tomography was 2,142.2±318.5 mm3, 3,132.9±632.1 mm3, and 2,741.5±380.4 mm3 in group 1, group 2, and group 3, respectively (p<0.05). Conclusions These results indicate that differences in the structural and mechanical properties of gelatin that are associated with jelly strength influenced cellular responses such as cell viability and bony tissue ingrowth, facilitating greater bone fusion around high jelly strength implants. PMID:26097660

  9. Corneal Stroma Regeneration with Acellular Corneal Stroma Sheets and Keratocytes in a Rabbit Model

    PubMed Central

    Ma, Xiao Yun; Zhang, Yun; Zhu, Dan; Lu, Yang; Zhou, Guangdong; Liu, Wei; Cao, Yilin; Zhang, Wen Jie

    2015-01-01

    Acellular corneal stroma matrix has been used for corneal stroma engineering. However, because of its compact tissue structure, regrowth of keratocytes into the scaffold is difficult. Previously, we developed a sandwich model for cartilage engineering using acellular cartilage sheets. In the present study, we tested this model for corneal stroma regeneration using acellular porcine corneal stroma (APCS) sheets and keratocytes. Porcine corneas were decellularized by NaCl treatment, and the APCS was cut into 20-μm-thick sheets. A rabbit corneal stroma defect model was created by lamellar keratoplasty and repaired by transplantation of five pieces of APCS sheets with keratocytes. Six months after transplantation, transparent corneas were present in the experimental group, which were confirmed by anterior segment optical coherence tomography examination and transmittance examination. The biomechanical properties in the experimental group were similar to those of normal cornea. Histological analyses showed an even distribution of keratocytes and well-oriented matrix in the stroma layer in the experimental group. Together, these results demonstrated that the sandwich model using acellular corneal stroma sheets and keratocytes could be potentially useful for corneal stroma regeneration. PMID:26167895

  10. 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

  11. Dynamic nanomechanics of individual bone marrow stromal cells and cell-matrix composites during chondrogenic differentiation.

    PubMed

    Lee, BoBae; Han, Lin; Frank, Eliot H; Grodzinsky, Alan J; Ortiz, Christine

    2015-01-01

    Dynamic nanomechanical properties of bovine bone marrow stromal cells (BMSCs) and their newly synthesized cartilage-like matrices were studied at nanometer scale deformation amplitudes. The increase in their dynamic modulus, |E(*)| (e.g., 2.4±0.4 kPa at 1 Hz to 9.7±0.2 kPa at 316 Hz at day 21, mean±SEM), and phase angle, δ, (e.g., 15±2° at 1 Hz to 74±1° at 316 Hz at day 21) with increasing frequency were attributed to the fluid flow induced poroelasticity, governed by both the newly synthesized matrix and the intracellular structures. The absence of culture duration dependence suggested that chondrogenesis of BMSCs had not yet resulted in the formation of a well-organized matrix with a hierarchical structure similar to cartilage. BMSC-matrix composites demonstrated different poro-viscoelastic frequency-dependent mechanical behavior and energy dissipation compared to chondrocyte-matrix composites due to differences in matrix molecular constituents, structure and cell properties. This study provides important insights into the design of optimal protocols for tissue-engineered cartilage products using chondrocytes and BMSCs. PMID:25468666

  12. Comparative efficacy of 2 different demineralized bone matrix allografts in treating long-bone nonunions in heavy tobacco smokers.

    PubMed

    Ziran, Bruce; Cheung, Sunny; Smith, Wade; Westerheide, Ken

    2005-07-01

    Smoking impairs bone healing and increases the risk for complications associated with nonunions. The efficacies of 2 different allografts, Grafton (demineralized bone matrix [DBM] in a gel-like glycerol carrier) and Orthoblast (DBM with a reverse thermal poloxamer carrier) were examined with respect to nonunions in patients who reported heavy tobacco use. The Grafton allograft was used in 25 patients, and the Orthoblast allograft was used in 13 patients. All patients smoked more than half a pack of cigarettes a day and did not use electric stimulators. A successful graft was defined as healing on the first graft attempt without complications or later regraft. The Grafton and Orthoblast success rates were 52% and 85%, respectively (P = .077). The unique thermal properties of the Orthoblast reverse poloxamer, which may enhance DBM osteoinduction, may account for the difference in success rates. Although results failed to reach statistical significance, the large difference and high likelihood ratio (4.2) between the 2 groups suggest that perhaps not all commercially available allografts may necessarily perform with the same efficacy with respect to heavy smokers. PMID:16130350

  13. [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. PMID:18717269

  14. Comparative evaluation of the osteoinductivity of two formulations of human demineralized bone matrix.

    PubMed

    Takikawa, Satoshi; Bauer, Thomas W; Kambic, Helen; Togawa, Daisuke

    2003-04-01

    In the United States, demineralized bone matrix (DBM) is considered a transplantable tissue and therefore is regulated primarily by the American Association of Tissue Banks. Even though DBM is not subjected to the same regulations relative to performance claims as medical devices are, one would expect different processing methods might yield DBM preparations of different osteoinductive potential. The purpose of this study was to use an established athymic rat model to compare the osteoinductive properties of two commercially available human DBMs prepared using different methods but having essentially identical product claims. Sixteen female athymic rats were used to test equivalent volumes of two lots each of Grafton Putty (Osteotech, Inc., Eatontown, NJ), Osteofil (Regeneration Technologies, Inc., Alachua, FL), and rat DBM. At 28 days after implantation, qualitative and semiquantitative microscopy showed no significant differences in bone formation between the two lots from each source, but rat DBM produced significantly more bone than Grafton, which produced significantly more bone than Osteofil. Our results suggest that methods of graft processing may represent a greater source of variability than do differences among individual donors. Whether these differences relate to methods of demineralization, carrier, dose of DBM per volume, or to some other factor remains to be determined. PMID:12635152

  15. 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

  16. The effect of enamel matrix derivative (Emdogain®) on gene expression profiles of human primary alveolar bone cells.

    PubMed

    Yan, X Z; Rathe, F; Gilissen, C; van der Zande, M; Veltman, J; Junker, R; Yang, F; Jansen, J A; Walboomers, X F

    2014-06-01

    Emdogain® is frequently used in regenerative periodontal treatment. Understanding its effect on gene expression of bone cells would enable new products and pathways promoting bone formation to be established. The aim of the study was to analyse the effect of Emdogain® on expression profiles of human-derived bone cells with the help of the micro-array, and subsequent validation. Bone was harvested from non-smoking patients during dental implant surgery. After outgrowth, cells were cultured until subconfluence, treated for 24 h with either Emdogain® (100 µg/ml) or control medium, and subsequently RNA was isolated and micro-array was performed. The most important genes demonstrated by micro-array data were confirmed by qPCR and ELISA tests. Emdogain tipped the balance between genes expressed for bone formation and bone resorption towards a more anabolic effect, by interaction of the PGE2 pathway and inhibition of IL-7 production. In addition the results of the present study indicate that Emdogain possibly has an effect on gene expression for extracellular matrix formation of human bone cells, in particular on bone matrix formation and on proliferation and differentiation. With the micro-array and the subsequent validation, the genes possibly involved in Emdogain action on bone cells were identified. These results can contribute to establishing new products and pathways promoting bone formation. PMID:22689476

  17. 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.

  18. Granule Size–Dependent Bone Regenerative Capacity of Octacalcium Phosphate in Collagen Matrix

    PubMed Central

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

    2012-01-01

    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. PMID:21942921

  19. A matrix lie group approach to statistical shape analysis of bones.

    PubMed

    Hefny, Mohamed S; Rudan, John F; Ellis, Randy E

    2014-01-01

    Statistical shape models using a principal-component analysis are inadequate for studying shapes that are in non-linear manifolds. Principal tangent components use a matrix Lie group that maps a non-linear manifold to a corresponding linear tangent space. Computations that are performed on the tangent space of the manifold use linear statistics to analyze non-linear shape spaces. The method was tested on bone surface from proximal femurs. Using only three components, the new model recovered 94% of the medical dataset, whereas a conventional method that used linear principal components needed 24 components to achieve the same reconstruction accuracy. PMID:24732500

  20. 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

  1. 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

  2. Osseous healing with a composite of allograft and demineralized bone matrix: adverse effects of smoking.

    PubMed

    Ziran, Bruce H; Hendi, Pooneh; Smith, Wade R; Westerheide, Kenneth; Agudelo, Juan F

    2007-04-01

    We report on our use of a composite graft of lyophilized cancellous allogenic chips and demineralized bone matrix (DBM; Grafton; Osteotech, Eatontown, NJ) to manage traumatic osseous defects and nonunions. Data were prospectively collected from all patients who received this composite bone graft between 1996 and 2000. Only acute fractures with bone loss resulting in a uncontained defect and atrophic non-unions were included in the present study. Demographic data and complications related to composite use, tobacco use, and other comorbidities that could affect healing were evaluated. One hundred seven patients (112 bone graft sites) were followed up for a mean of 32 months (range, 12-60 months). Graft sites included the forearm, femur and tibia. Of the 112 patients, there were 56 smokers (25 non-unions and 31 fractures) and 56 non-smokers (28 fractures and 28 non-unions). Healing occured in 38/56 smokers compared with 49/56 non-smokers. In failed cases, smoking was characteristic in 7/9 non-unions and 11/16 fractures. There were 26 acute uncontained injuries, 29 acute contained defects, and 67 nonunions. Grafting sites were radius/ulna (13 cases), humerus (17), femur (31), and tibia/fibula (51). Significant comorbidities were diabetes mellitus (4 cases), fungal osteomyelitis (1), and pulmonary alveolar proteinosis (1). Eight (73%) of the 11 patients with graft failure had a significant smoking history. This composite graft is an option for managing osseous defects and nonunions traditionally treated with autologous bone grafting but should be used with caution when treating patients who are smokers. PMID:17515188

  3. 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

  4. Age-dependence of power spectral density and fractal dimension of bone mineralized matrix in atomic force microscope topography images: potential correlates of bone tissue age and bone fragility in female femoral neck trabeculae

    PubMed Central

    Milovanovic, Petar; Djuric, Marija; Rakocevic, Zlatko

    2012-01-01

    There is an increasing interest in bone nano-structure, the ultimate goal being to reveal the basis of age-related bone fragility. In this study, power spectral density (PSD) data and fractal dimensions of the mineralized bone matrix were extracted from atomic force microscope topography images of the femoral neck trabeculae. The aim was to evaluate age-dependent differences in the mineralized matrix of human bone and to consider whether these advanced nano-descriptors might be linked to decreased bone remodeling observed by some authors and age-related decline in bone mechanical competence. The investigated bone specimens belonged to a group of young adult women (n = 5, age: 20–40 years) and a group of elderly women (n = 5, age: 70–95 years) without bone diseases. PSD graphs showed the roughness density distribution in relation to spatial frequency. In all cases, there was a fairly linear decrease in magnitude of the power spectra with increasing spatial frequencies. The PSD slope was steeper in elderly individuals (−2.374 vs. −2.066), suggesting the dominance of larger surface morphological features. Fractal dimension of the mineralized bone matrix showed a significant negative trend with advanced age, declining from 2.467 in young individuals to 2.313 in the elderly (r = 0.65, P = 0.04). Higher fractal dimension in young women reflects domination of smaller mineral grains, which is compatible with the more freshly remodeled structure. In contrast, the surface patterns in elderly individuals were indicative of older tissue age. Lower roughness and reduced structural complexity (decreased fractal dimension) of the interfibrillar bone matrix in the elderly suggest a decline in bone toughness, which explains why aged bone is more brittle and prone to fractures. PMID:22946475

  5. 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

  6. 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. PMID:26228909

  7. 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

  8. Design and Synthesis of an Artificial Pulmonary Pleura for High Throughput Studies in Acellular Human Lungs

    PubMed Central

    Wagner, Darcy E.; Fenn, Spencer L.; Bonenfant, Nicholas R.; Marks, Elliot R.; Borg, Zachary; Saunders, Patrick; Oldinski, Rachael A.; Weiss, Daniel J.

    2015-01-01

    Whole organ decellularization of complex organs, such as lungs, presents a unique opportunity for use of acellular scaffolds for ex vivo tissue engineering or for studying cell-extracellular matrix interactions ex vivo. A growing body of literature investigating decellularizing and recellularizing rodent lungs has provided important proof of concept models and rodent lungs are readily available for high throughput studies. In contrast, comparable progress in large animal and human lungs has been impeded owing to more limited availability and difficulties in handling larger tissue. While the use of smaller segments of acellular large animal or human lungs would maximize usage from a single lung, excision of small acellular segments compromises the integrity of the pleural layer, leaving the terminal ends of blood vessels and airways exposed. We have developed a novel pleural coating using non-toxic ionically crosslinked alginate or photocrosslinked methacrylated alginate which can be applied to excised acellular lung segments, permits inflation of small segments, and significantly enhances retention of cells inoculated through cannulated airways or blood vessels. Further, photocrosslinking methacrylated alginate, using eosin Y and triethanolamine (TEOA) at 530nm wavelength, results in a mechanically stable pleural coating that permits effective cyclic 3-dimensional stretch, i.e. mechanical ventilation, of individual segments. PMID:25750684

  9. 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

  10. 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

  11. 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

  12. 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

  13. 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

  14. 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

  15. Quantitative bone matrix density measurement by water- and fat-suppressed proton projection MRI (WASPI) with polymer calibration phantoms.

    PubMed

    Cao, Haihui; Ackerman, Jerome L; Hrovat, Mirko I; Graham, Lila; Glimcher, Melvin J; Wu, Yaotang

    2008-12-01

    The density of the organic matrix of bone substance is a critical parameter necessary to clinically evaluate and distinguish structural and metabolic pathological conditions such as osteomalacia in adults and rickets in growing children. Water- and fat-suppressed proton projection MRI (WASPI) was developed as a noninvasive means to obtain this information. In this study, a density calibration phantom was developed to convert WASPI intensity to true bone matrix density. The phantom contained a specifically designed poly(ethylene oxide)/poly(methyl methacrylate) (PEO/PMMA) blend, whose MRI properties (T(1), T(2), and resonance linewidth) were similar to those of solid bone matrix (collagen, tightly bound water, and other immobile molecules), minimizing the need to correct for differences in T(1) and/or T(2) relaxation between the phantom and the subject. Cortical and trabecular porcine bone specimens were imaged using WASPI with the calibration phantom in the field of view (FOV) as a stable intensity reference. Gravimetric and amino acid analyses were carried out on the same specimens after WASPI, and the chemical results were found to be highly correlated (r(2) = 0.98 and 0.95, respectively) to the WASPI intensity. By this procedure the WASPI intensity can be used to obtain the true bone matrix mass density in g cm(-3). PMID:19025909

  16. 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

  17. 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

  18. Development and Characterization of Acellular Porcine Pulmonary Valve Scaffolds for Tissue Engineering

    PubMed Central

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

    2014-01-01

    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

  19. 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

  20. Comparison of equine bone marrow-, umbilical cord matrix and amniotic fluid-derived progenitor cells.

    PubMed

    Lovati, Arianna Barbara; Corradetti, Bruna; Lange Consiglio, Anna; Recordati, Camilla; Bonacina, Elisa; Bizzaro, Davide; Cremonesi, Fausto

    2011-02-01

    The aim of the study was to compare in vitro the stemness features of horse progenitor cells derived from bone marrow (BM-MSCs), amniotic fluid (AF-MSCs) and umbilical cord matrix (EUC-MSCs). It has been suggested that there may be a stem cell population within both umbilical cord matrix and amniotic fluid. However, little knowledge exists about the characteristics of these progenitor cells within these sources in the equine species. This study wanted to investigate an alternative and non-invasive stem cell source for the equine tissue engineering and to learn more about the properties of these cells for future cell banking. Bone marrow, umbilical cord and amniotic fluid samples were harvested from different horses. Cells were analyzed for proliferation, immunocytochemical, stem cell gene expression and multilineage plasticity. BM- and AF-MSCs took similar time to reach confluence and showed comparable plating efficiency. All cell lines expressed identical stem cell markers and capability to differentiate towards osteogenic lineage. Almost all cell lines differentiated into the adipogenic lineage as demonstrated by cytochemical staining, even if no adipose gene expression was detectable for AF-MSCs. AF- and EUC-MSCs showed a limited chondrogenic differentiation compared with BM-MSCs as demonstrated by histological and biochemical analyses. These findings suggest that AF-MSCs appeared to be a readily obtainable and highly proliferative cell line from an uninvasive source that may represent a good model system for stem cell biology. More studies are needed to investigate their multilineage potential. EUC-MSCs need to be further investigated regarding their particular behavior in vitro represented by spheroid formation. PMID:21193959

  1. Evidence from Raman Spectroscopy of a Putative Link Between Inherent Bone Matrix Chemistry and Degenerative Joint Disease

    PubMed Central

    Kerns, Jemma G; Gikas, Panagiotis D; Buckley, Kevin; Shepperd, Adam; Birch, Helen L; McCarthy, Ian; Miles, Jonathan; Briggs, Timothy W R; Keen, Richard; Parker, Anthony W; Matousek, Pavel; Goodship, Allen E

    2014-01-01

    Objective Osteoarthritis (OA) is a common debilitating disease that results in degeneration of cartilage and bone in the synovial joints. Subtle changes in the molecular structure of the subchondral bone matrix occur and may be associated with cartilage changes. The aim of this study was to explore whether the abnormal molecular changes observed in the matrix of OA subchondral bone can be identified with Raman spectroscopy. Methods Tibial plateaus from patients undergoing total knee replacement for OA (n = 10) were compared with healthy joints from patients undergoing leg amputation (n = 5; sex- and laterality-matched) and with non-OA cadaveric knee specimens (n = 5; age-matched). The samples were analyzed with Raman spectroscopy, peripheral quantitative computed tomography, and chemical analysis to compare changes in defined load-bearing sites in both the medial and lateral compartments. Results OA subchondral bone matrix changes were detected by Raman spectroscopy. Within each cohort, there was no spectral difference in bone matrix chemistry between the medial and lateral compartments, whereas a significant spectral difference (P < 0.001) was observed between the non-OA and OA specimens. Type I collagen chain ratios were normal in the non-OA specimens but were significantly elevated in the OA specimens. Conclusion In comparing the results of Raman spectroscopy with those obtained by other standard techniques, these findings show, for the first time, that subchondral bone changes, or inherent differences, exist in both the medial and lateral (beneath intact cartilage) compartments of OA knees. The development of Raman spectroscopy as a screening tool, based on molecular-specific modifications in bone, would facilitate the identification of clinical disease, including early molecular changes. PMID:24470432

  2. Histological analysis of cells and matrix mineralization of new bone tissue induced in rabbit femur bones by Mg-Zr based biodegradable implants.

    PubMed

    Ragamouni, Sravanthi; Kumar, Jerald Mahesh; Mushahary, Dolly; Nemani, Harishankar; Pande, Gopal

    2013-09-01

    The biological efficacy of bone inducing implant materials in situ can be assessed effectively by performing histological analysis. We studied the peri-implant bone regeneration around two types of biodegradable magnesium-zirconium alloys, Mg-5Zr and Mg-Zr-2Sr, using histological, histochemical and immunohistochemical methods in the femur of New Zealand White strain rabbits. Our study includes three animal groups: (a) Mg-5Zr, (b) Mg-Zr-2Sr and (c) control. In each group three animals were used and in groups 'a' and 'b' the respective alloys were implanted in cavities made at the distal ends of the femur; control animals were left without implants to observe natural bone healing. Qualitative assessment of the cellularity and matrix mineralization events of the newly formed bone tissue was done at three months after implantation by histological methods in methyl methacrylate embedded tissue without decalcifying the bone. Quantitative mineral content and density of the new bone (NB) were evaluated by the statistical analysis of dual energy X-ray absorptiometry (DXA) data obtained from three animals in each experimental group. Based on our analysis we conclude that Mg-Zr-2Sr alloy showed better osseointegration of the newly formed bone with the implant surface. Our methodology of studying peri-implant osteoinduction of degradable implants using low temperature methyl methacrylate embedding resin can be useful as a general method for determining the bio-efficacy of implant materials. PMID:23628266

  3. Cartilage damage involving extrusion of mineralisable matrix from the articular calcified cartilage and subchondral bone.

    PubMed

    Boyde, A; Riggs, C M; Bushby, A J; McDermott, B; Pinchbeck, G L; Clegg, P D

    2011-01-01

    Arthropathy of the distal articular surfaces of the third metacarpal (Mc3) and metatarsal (Mt3) bones in the Thoroughbred racehorse (Tb) is a natural model of repetitive overload arthrosis. We describe a novel pathology that affects the articular calcified cartilage (ACC) and subchondral bone (SCB) and which is associated with hyaline articular cartilage degeneration. Parasagittal slices cut from the palmar quadrant of the distal condyles of the left Mc3/Mt3 of 39 trained Tbs euthanized for welfare reasons were imaged by point projection microradiography, and backscattered electron (BSE) scanning electron microscopy (SEM), light microscopy, and confocal scanning light microscopy. Mechanical properties were studied by nanoindentation. Data on the horses' training and racing career were also collected. Highly mineralised projections were observed extending from cracks in the ACC mineralising front into the hyaline articular cartilage (HAC) up to two-thirds the thickness of the HAC, and were associated with focal HAC surface fibrillation directly overlying their site. Nanoindentation identified this extruded matrix to be stiffer than any other mineralised phase in the specimen by a factor of two. The presence of projections was associated with a higher cartilage Mankin histology score (P<0.02) and increased amounts of gross cartilage loss pathologically on the condyle (P<0.02). Presence of projections was not significantly associated with: total number of racing seasons, age of horse, amount of earnings, number of days in training, total distance galloped in career, or presence of wear lines. PMID:21623571

  4. 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. PMID:25453953

  5. Fabrication method, structure, mechanical, and biological properties of decellularized extracellular matrix for replacement of wide bone tissue defects.

    PubMed

    Anisimova, N Y; Kiselevsky, M V; Sukhorukova, I V; Shvindina, N V; Shtansky, D V

    2015-09-01

    The present paper was focused on the development of a new method of decellularized extracellular matrix (DECM) fabrication via a chemical treatment of a native bone tissue. Particular attention was paid to the influence of chemical treatment on the mechanical properties of native bones, sterility, and biological performance in vivo using the syngeneic heterotopic and orthotopic implantation models. The obtained data indicated that after a chemical decellularization treatment in 4% aqueous sodium chlorite, no noticeable signs of the erosion of compact cortical bone surface or destruction of trabeculae of spongy bone in spinal channel were observed. The histological studies showed that the chemical treatment resulted in the decellularization of both bone and cartilage tissues. The DECM samples demonstrated no signs of chemical and biological degradation in vivo. Thorough structural characterization revealed that after decellularization, the mineral frame retained its integrity with the organic phase; however clotting and destruction of organic molecules and fibers were observed. FTIR studies revealed several structural changes associated with the destruction of organic molecules, although all organic components typical of intact bone were preserved. The decellularization-induced structural changes in the collagen constituent resulted changed the deformation under compression mechanism: from the major fracture by crack propagation throughout the sample to the predominantly brittle fracture. Although the mechanical properties of radius bones subjected to decellularization were observed to degrade, the mechanical properties of ulna bones in compression and humerus bones in bending remained unchanged. The compressive strength of both the intact and decellularized ulna bones was 125-130 MPa and the flexural strength of humerus bones was 156 and 145 MPa for the intact and decellularized samples, respectively. These results open new avenues for the use of DECM samples as

  6. 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. PMID:23400420

  7. 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. PMID:21233742

  8. 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

  9. Demineralized Bone Matrix Combined Bone Marrow Mesenchymal Stem Cells, Bone Morphogenetic Protein-2 and Transforming Growth Factor-β3 Gene Promoted Pig Cartilage Defect Repair

    PubMed Central

    Wang, Xin; Li, Yanlin; Han, Rui; He, Chuan; Wang, Guoliang; Wang, Jianwei; Zheng, Jiali; Pei, Mei; Wei, Lei

    2014-01-01

    Objectives To investigate whether a combination of demineralized bone matrix (DBM) and bone marrow mesenchymal stem cells (BMSCs) infected with adenovirus-mediated- bone morphogenetic protein (Ad-BMP-2) and transforming growth factor-β3 (Ad-TGF-β3) promotes the repair of the full-thickness cartilage lesions in pig model. Methods BMSCs isolated from pig were cultured and infected with Ad-BMP-2(B group), Ad-TGF-β3 (T group), Ad-BMP-2 + Ad-TGF-β3(BT group), cells infected with empty Ad served as a negative group(N group), the expression of the BMP-2 and TGF-β3 were confirmed by immunofluorescence, PCR, and ELISA, the expression of SOX-9, type II collagen(COL-2A), aggrecan (ACAN) in each group were evaluated by real-time PCR at 1w, 2w, 3w, respectively. The chondrogenic differentiation of BMSCs was evaluated by type II collagen at 21d with immunohistochemical staining. The third-passage BMSCs infected with Ad-BMP-2 and Ad-TGF-β3 were suspended and cultured with DBM for 6 days to construct a new type of tissue engineering scaffold to repair full-thickness cartilage lesions in the femur condyles of pig knee, the regenerated tissue was evaluated at 1,2 and 3 months after surgery by gross appearance, H&E, safranin O staining and O'driscoll score. Results Ad-BMP-2 and Ad-TGF-β3 (BT group) infected cells acquired strong type II collagen staining compared with Ad-BMP-2 (B group) and Ad-TGF-β3 (T group) along. The Ad-BMP-2 and Ad-TGF-β3 infected BMSCs adhered and propagated well in DBM and the new type of tissue engineering scaffold produced hyaline cartilage morphology containing a stronger type II collagen and safranin O staining, the O'driscoll score was higher than other groups. Conclusions The DBM compound with Ad-BMP-2 and Ad-TGF-β3 infected BMSCs scaffold has a good biocompatibility and could well induce cartilage regeneration to repair the defects of joint cartilage. This technology may be efficiently employed for cartilage lesions repair in vivo. PMID

  10. 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

  11. The bone matrix protein secreted phosphoprotein 24 kD (Spp24): bone metabolism regulator and starting material for biotherapeutic materials.

    PubMed

    Murray, Samuel S; Wang, Jeffrey C; Duarte, Maria Eugenia Leite; Zhao, Ke-Wei; Tian, Haijun; Francis, Timothy; Brochmann Murray, Elsa J

    2015-05-01

    Secreted phosphoprotein 24 kD (Spp24) is a bone matrix protein that appears to be derived primarily from the liver and delivered to other tissues in a protective complex. A significant role in bone growth and turnover is suggested by genetic studies that associate the gene locus (SPP2) with bone mineral density and bone quality. The function of this protein in the normal bone environment is unknown but clues are given by the fact that Spp24, or proteolytic products of Spp24, bind cytokines of the TGF-β superfamily and also activate intracellular signaling pathways. Several potential biotherapeutics have been engineered from this protein including materials that enhance BMP-induced bone healing and, on the other hand, materials that inhibit BMPs in clinical situations where this is called for such as reducing BMP-induced inflammation and inhibiting tumors dependent on BMP autocrine systems. As understanding of the structure and function of this protein increases, more opportunities for rationally developed therapeutics will become apparent. PMID:25339413

  12. 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

  13. 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

  14. On fragmenting, densely mineralised acellular protrusions into articular cartilage and their possible role in osteoarthritis.

    PubMed

    Boyde, A; Davis, G R; Mills, D; Zikmund, T; Cox, T M; Adams, V L; Niker, A; Wilson, P J; Dillon, J P; Ranganath, L R; Jeffery, N; Jarvis, J C; Gallagher, J A

    2014-10-01

    High density mineralised protrusions (HDMP) from the tidemark mineralising front into hyaline articular cartilage (HAC) were first described in Thoroughbred racehorse fetlock joints and later in Icelandic horse hock joints. We now report them in human material. Whole femoral heads removed at operation for joint replacement or from dissection room cadavers were imaged using magnetic resonance imaging (MRI) dual echo steady state at 0.23 mm resolution, then 26-μm resolution high contrast X-ray microtomography, sectioned and embedded in polymethylmethacrylate, blocks cut and polished and re-imaged with 6-μm resolution X-ray microtomography. Tissue mineralisation density was imaged using backscattered electron SEM (BSE SEM) at 20 kV with uncoated samples. HAC histology was studied by BSE SEM after staining block faces with ammonium triiodide solution. HDMP arise via the extrusion of an unknown mineralisable matrix into clefts in HAC, a process of acellular dystrophic calcification. Their formation may be an extension of a crack self-healing mechanism found in bone and articular calcified cartilage. Mineral concentration exceeds that of articular calcified cartilage and is not uniform. It is probable that they have not been reported previously because they are removed by decalcification with standard protocols. Mineral phase morphology frequently shows the agglomeration of many fine particles into larger concretions. HDMP are surrounded by HAC, are brittle, and show fault lines within them. Dense fragments found within damaged HAC could make a significant contribution to joint destruction. At least larger HDMP can be detected with the best MRI imaging ex vivo. PMID:25132002

  15. 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

  16. 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. PMID:25773047

  17. MicroRNAs associated with osteoarthritis differently expressed in bone matrix gelatin (BMG) rat model

    PubMed Central

    Min, Zixin; zhang, Rui; Yao, Jianfeng; Jiang, Congshan; Guo, Yuanxu; Cong, Fei; Wang, Wei; Tian, Jia; Zhong, Nannan; Sun, Jian; Ma, Jie; Lu, Shemin

    2015-01-01

    Osteoarthritis (OA) is characterized by degeneration of articular cartilage, limited intraarticular inflammation with synovitis, and changes in peri-articular and subchondral bone. In recent years, more and more evidence demonstrated that microRNAs (miRNAs) play important roles in the molecular mechanisms in OA by suppressing gene expression at the post-transcriptional level. In current study, histological staining of toluidine blue and cartilage-specific gene express revealed that the bone matrix gelatin (BMG) rat model could demonstrate the different development of cartilage. In current study, we tested whether some miRNAs associated with OA differently expressed in BMG rat model. We verified that miR-140 and miR-455 were associated with cartilage development, and further revealed that miR-140-5p and miR-455-3p might play more important function than miR-140-3p and miR-455-5p in the BMG rat model. Moreover, we found that miR-9 and miR-98 were involved in the endochondral ossification, suggesting they may be also the key regulators in the process of endochondral ossification. In fact, many miRNAs worked as a miRNA-mediated regulatory network in the process of cartilage development and OA. Further functional discovery will clarify the roles of individual miRNAs and their targets, and serve as a strong foundation for translating these findings to the clinic therapy for OA. PMID:25785087

  18. Scaffolds for bone regeneration made of hydroxyapatite microspheres in a collagen matrix.

    PubMed

    Cholas, Rahmatullah; Kunjalukkal Padmanabhan, Sanosh; Gervaso, Francesca; Udayan, Gayatri; Monaco, Graziana; Sannino, Alessandro; Licciulli, Antonio

    2016-06-01

    Biomimetic scaffolds with a structural and chemical composition similar to native bone tissue may be promising for bone tissue regeneration. In the present work hydroxyapatite mesoporous microspheres (mHA) were incorporated into collagen scaffolds containing an ordered interconnected macroporosity. The mHA were obtained by spray drying of a nano hydroxyapatite slurry prepared by the precipitation technique. X-ray diffraction (XRD) analysis revealed that the microspheres were composed only of hydroxyapatite (HA) phase, and energy-dispersive x-ray spectroscopy (EDS) analysis revealed the Ca/P ratio to be 1.69 which is near the value for pure HA. The obtained microspheres had an average diameter of 6μm, a specific surface area of 40m(2)/g as measured by Brunauer-Emmett-Teller (BET) analysis, and Barrett-Joyner-Halenda (BJH) analysis showed a mesoporous structure with an average pore diameter of 16nm. Collagen/HA-microsphere (Col/mHA) composite scaffolds were prepared by freeze-drying followed by dehydrothermal crosslinking. SEM observations of Col/mHA scaffolds revealed HA microspheres embedded within a porous collagen matrix with a pore size ranging from a few microns up to 200μm, which was also confirmed by histological staining of sections of paraffin embedded scaffolds. The compressive modulus of the composite scaffold at low and high strain values was 1.7 and 2.8 times, respectively, that of pure collagen scaffolds. Cell proliferation measured by the MTT assay showed more than a 3-fold increase in cell number within the scaffolds after 15days of culture for both pure collagen scaffolds and Col/mHA composite scaffolds. Attractive properties of this composite scaffold include the potential to load the microspheres for drug delivery and the controllability of the pore structure at various length scales. PMID:27040244

  19. Diosgenin stimulates osteogenic activity by increasing bone matrix protein synthesis and bone-specific transcription factor Runx2 in osteoblastic MC3T3-E1 cells.

    PubMed

    Alcantara, Ethel H; Shin, Mee-Young; Sohn, Ho-Yong; Park, Youn-Moon; Kim, Taewan; Lim, Jae-Hwan; Jeong, Hyung-Jin; Kwon, Soon-Tae; Kwun, In-Sook

    2011-11-01

    Diosgenin, a steroid saponin extracted from the root of wild yam (Dioscorea villossa) is claimed to have osteogenic property. However, detailed studies providing evidence to this claim have not been fully undertaken. In this study, we investigated the effect of diosgenin on the osteogenesis of murine MC3T3-E1 osteoblastic cells. Cells were cultured with varying levels of diosgenin (0-10 μM) within 25 days of bone formation period. Diosgenin was found to stimulate proliferation within the range of 0.01-5 μM using MTT assay. The medium and cellular levels of Type 1 collagen and alkaline phosphatase (ALP), both of which are major bone matrix proteins, increased within the low range of diosgenin concentration (>0-3 μM), and this pattern was further confirmed by collagen and ALP staining of the extracellular matrix (ECM). The cellular protein expression of ALP and collagen Type 1 was also increased at 0.1-1 μM diosgenin treatment as analyzed by Western blot. Calcium deposition within the ECM also showed the same pattern as assessed by Alizarin Red S and Von Kossa staining. Bone-specific transcription factor runt-related transcription factor 2 (Runx2) and Runx2-regulated osteopontin protein expressions were induced at low concentration (0.1-1 μM) and again decreased with high diosgenin concentrations. Based on our findings, our study suggests that diosgenin can enhance bone formation by stimulating the synthesis and secretion of Type 1 collagen and ALP and bone marker proteins Runx2 and osteopontin expression. The increased levels of these marker proteins, in turn, can increase the formation of calcium deposits within the ECM thereby increasing bone formation. PMID:21292464

  20. Mechanisms by which acellular biologic scaffolds promote functional skeletal muscle restoration.

    PubMed

    Badylak, Stephen F; Dziki, Jenna L; Sicari, Brian M; Ambrosio, Fabrisia; Boninger, Michael L

    2016-10-01

    Acellular biologic scaffolds derived from extracellular matrix have been investigated in preclinical and clinical studies as a regenerative medicine approach for volumetric muscle loss treatment. The present manuscript provides a review of previous studies supporting the use of extracellular matrix derived biologic scaffolds for the promotion of functional skeletal muscle tissue formation that is contractile and innervated. The manuscript also identifies key mechanisms that have been associated with ECM-mediated skeletal muscle repair, and provides hypotheses as to why there have been variable outcomes, ranging from successful to unsatisfactory, associated with ECM bioscaffold implantation in the skeletal muscle injury microenvironment. PMID:27376561

  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. Eight-year results of site retention of anorganic bovine bone and anorganic bovine matrix.

    PubMed

    Degidi, Marco; Perrotti, Vittoria; Piattelli, Adriano; Iezzi, Giovanna

    2013-12-01

    The long-term fate of some biomaterials is still unknown, and the reports present in the literature are not conclusive as to whether these biomaterials are resorbed over time or not. Different reports can be found with regard to the resorption behavior of anorganic bovine bone (ABB). The aim of the present study was to provide a comparative histological and histomorphometrical evaluation, in the same patient, of 2 specimens retrieved from a sinus augmented with ABB and with anorganic bovine matrix added to a cell-binding peptide (PepGen P-15), respectively, after a healing period of 6 months and after 8 years of implant loading, to evaluate the resorption of both biomaterials. A unilateral sinus augmentation procedure with ABB (50%) and with PepGen P-15 (50%) was performed in a 54-year-old male patient. Two titanium dental implants with a sandblasted and acid-etched surface were inserted after 6 months. During this procedure, 2 tissue cores were retrieved from the sinus with a trephine, before implant insertion. After an additional 6 months, a fixed prosthetic restoration was fabricated. One of these implants, after a loading period of 8 years, fractured in the coronal portion and was removed. Both specimens, one retrieved after a 6-month healing period and the other after an 8-year loading period, were treated to obtain thin ground sections. In the 6-month specimen, the histomorphometry showed that the percentage of newly formed bone was 27.2% ± 3.6%, marrow spaces 35.6% ± 2.3%, residual ABB particles 25.1% ± 1.2%, and residual PepGen P-15 particles 12.1% ± 2.2%. In the 8-year specimen, the histomorphometry showed that the percentage of newly formed bone was 51.4% ± 4.8%, marrow spaces 40% ± 7.1%, residual ABB particles 6.2% ± 0.7%, and residual PepGen P-15 particles 2.4% ± 0.5%. Both biomaterials underwent significant resorption over the course of this study. PMID:22103882

  3. 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

  4. 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

  5. The use of fibre-based demineralised bone matrix in major acetabular reconstruction: surgical technique and preliminary results

    PubMed Central

    Karoubi, Mathieu; Dumaine, Valérie; Courpied, Jean Pierre

    2010-01-01

    Acetabular osteolysis associated with socket loosening is one of the main long-term complications of total hip arthroplasty. In case of major bone loss, where <50% host bone coverage can be obtained with a porous-coated cementless cup, it is generally agreed that a metal ring or cage in association with a cemented component and allograft bone should be used. In order to promote allograft bone consolidation and incorporation, we have associated demineralised bone matrix (DBM, Grafton® A Flex) to the construct ion. Here we describe the technical details of major acetabular reconstruction using the Kerboull acetabular reinforcement device with allograft bone and DBM. This device has a hook that must be placed under the teardrop of the acetabulum and a plate for iliac fixation. The main advantages of this device are help in restoring the normal centre of hip rotation, guiding the reconstruction and partially unloading the graft. The Kerboull acetabular reinforcement device has provided a 92% survival rate free of loosening at 13-year follow-up in a consecutive series of 60 type III and IV deficiencies. Our preliminary results using DBM indicate faster allograft consolidation and remodelling. PMID:21057788

  6. 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

  7. A comparison of commercially available demineralized bone matrix for spinal fusion.

    PubMed

    Wang, Jeffrey C; Alanay, A; Mark, Davies; Kanim, Linda E A; Campbell, Pat A; Dawson, Edgar G; Lieberman, Jay R

    2007-08-01

    In an effort to augment the available grafting material as well as to increase spinal fusion rates, the utilization of a demineralized bone matrix (DBM) as a graft extender or replacement is common. There are several commercially available DBM substances available for use in spinal surgery, each with different amounts of DBM containing osteoinductive proteins. Each product may have different osteoinductivity potential due to different methods of preparation, storage, and donor specifications. The purpose of this study is to prospectively compare the osteoinductive potential of three different commercially available DBM substances in an athymic rodent spinal fusion model and to discuss the reasons of the variability in osteoinductivity. A posterolateral fusion was performed in 72 mature athymic nude female rats. Three groups of 18 rats were implanted with 1 of 3 DBMs (Osteofil, Grafton, and Dynagraft). A fourth group was implanted with rodent autogenous iliac crest bone graft. The rats were sacrificed at 2, 4, 6, and 8 weeks. A dose of 0.3 cm(3) per side (0.6 cm(3)per animal) was used for each substance. Radiographs were taken at 2 weeks intervals until sacrifice. Fusion was determined by radiographs, manual palpation, and histological analysis. The Osteofil substance had the highest overall fusion rate (14/18), and the highest early 4 weeks fusion rate of (4/5). Grafton produced slightly lower fusion rates of (11/17) overall, and lower early 4 weeks fusion rate of (2/5). There was no statistically significant difference between the rate of fusion after implantation of Osteofil and Grafton. None of the sites implanted with Dynagraft fused at any time point (0/17), and there was a significantly lower fusion rate between the Dynagraft and the other two substances at the six-week-time point and for final fusion rate (P = 0.0001, Fischer's exact test). None of the autogenous iliac crest animals fused at any time point. Non-decalcified histology confirmed the presence of

  8. Megakaryocytes contribute to the bone marrow-matrix environment by expressing fibronectin, type IV collagen and laminin

    PubMed Central

    Malara, Alessandro; Currao, Manuela; Gruppi, Cristian; Celesti, Giuseppe; Viarengo, Gianluca; Buracchi, Chiara; Laghi, Luigi; Kaplan, David L.; Balduini, Alessandra

    2014-01-01

    Megakaryocytes associate with the bone marrow vasculature where they convert their cytoplasm into proplatelets that protrude through the vascular endothelium into the lumen and release platelets. The extracellular matrix (ECM) microenvironment plays a critical role in regulating these processes. In this work we demonstrate that, among bone marrow ECM components, fibronectin, type IV collagen and laminin are the most abundant around bone marrow sinusoids and constitute a peri-cellular matrix surrounding megakaryocytes. Most importantly, we report, for the first time, that megakaryocytes express components of the basement membrane and that these molecules contribute to the regulation of megakaryocyte development and bone marrow ECM homeostasis both in vitro and in vivo. In vitro, fibronectin induced a three-fold increase in the proliferation rate of mouse hematopoietic stem cells leading to higher megakaryocyte output with respect to cells treated only with thrombopoietin or other matrices. However, megakaryocyte ploidy level in fibronectin-treated cultures was significantly reduced. Stimulation with type IV collagen resulted in a 1.4-fold increase in megakaryocyte output, while all tested matrices supported proplatelet formation to a similar extent in megakaryocytes derived from fetal liver progenitor cells. In vivo, megakaryocyte expression of fibronectin and basement membrane components was up-regulated during bone marrow reconstitution upon 5-fluorouracil induced myelosuppression, while only type IV collagen resulted up-regulated upon induced thrombocytopenia. In conclusion, this work demonstrates that ECM components impact megakaryocyte behavior differently during their differentiation and highlights a new role for megakaryocyte as ECM-producing cells for the establishment of cell niches during bone marrow regeneration. PMID:24357118

  9. Bone mineral density, bone mineral content, gingival crevicular fluid (matrix metalloproteinases, cathepsin K, osteocalcin), and salivary and serum osteocalcin levels in human mandible and alveolar bone under conditions of simulated microgravity.

    PubMed

    Rai, Balwant; Kaur, Jasdeep; Catalina, Maria

    2010-09-01

    In astronauts and cosmonauts, exposure to microgravity has been associated with several physiological changes, including an osteoporosis like loss of bone mass. It has been reported that head-down tilt bed-rest studies mimic many of the observations seen in space flights. There has been no study of the effects of mandibular bone and alveolar bone loss in both sexes under conditions of simulated microgravity. This study was designed to investigate bone mineral density; bone mineral content; matrix metalloproteinase (MMP)-8, MMP-9, cathepsin K, and osteocalcin levels in gingival crevicular fluid (GCF); and salivary and serum osteocalcin levels in normal healthy men and women under conditions of simulated microgravity, namely, -6° head-down-tilt (HDT) bed rest. The subjects of this investigation were 10 male and 10 female volunteers who were exposed to 3 weeks of -6° HDT bed rest. Dual-energy X-ray absorptiometry was used to measure bone density and bone mineral content in alveolar bone from the mandibular canine to the third molar, as well as in the mandibular ramus, before, during, and after exposure to conditions of simulated microgravity. GCF (ie, MMP-8, MMP-9, cathepsin K, and osteocalcin) and salivary and serum osteocalcin levels were measured by enzyme-linked immunosorbent assays. Bone mineral density and bone mineral content were significantly lower under conditions of simulated microgravity in both sexes. The decreases were greater in women than in men, but the differences between sexes were not significant. Cathepsin, osteocalcin, MMP-8, and MMP-9 levels were significantly higher under conditions of simulated microgravity than under normal conditions; the increases were greater in women than in men, but the differences were not significant. Additional, more comprehensive, studies with larger sample sizes are now necessary for the investigation of simulated microgravity and microgravity. PMID:20881330

  10. Morphological and mechanical characterization of composite bone cement containing polymethylmethacrylate matrix functionalized with trimethoxysilyl and bioactive glass.

    PubMed

    Puska, Mervi; Moritz, Niko; Aho, Allan J; Vallittu, Pekka K

    2016-06-01

    Medical polymers of biostable nature (e.g. polymethylmetacrylate, PMMA) are widely used in various clinical applications. In this study, novel PMMA-based composite bone cement was prepared. Bioactive glass (BAG) particulate filler (30wt%) was added to enhance potentially the integration of bone to the cement. The polymer matrix was functionalized with trimethoxysilyl to achieve an interfacial bond between the matrix and the fillers of BAG. The amount of trimethoxysilyl in the monomer system varied from 0 to 75wt%. The effects of dry and wet (simulated body fluid, SBF at +37°C for 5 weeks) conditions were investigated. In total, 20 groups of specimens were prepared. The specimens were subjected to a destructive mechanical test in compression. Scanning electron microscopy (SEM) and micro-computed tomography (micro-CT) were used to study the surface and the three-dimensional morphology of the specimens. The results of the study indicated that the addition of trimethoxysilyl groups led to the formation of a hybrid polymer matrix which, in lower amounts (<10wt% of total weight), did not significantly affect the compression properties. However, when the specimens stored in dry and wet conditions were compared, the water sorption increased the compression strength (~5-10MPa per test group). At the same time, the water sorption also caused an evident porous structure formation for the specimens containing BAG and siloxane formation in the hybrid polymer matrix. PMID:26741375

  11. 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.

  12. 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

  13. 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

  14. 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

  15. Genomic analysis of a spontaneous model of breast cancer metastasis to bone reveals a role for the extracellular matrix.

    PubMed

    Eckhardt, Bedrich L; Parker, Belinda S; van Laar, Ryan K; Restall, Christina M; Natoli, Anthony L; Tavaria, Michael D; Stanley, Kym L; Sloan, Erica K; Moseley, Jane M; Anderson, Robin L

    2005-01-01

    A clinically relevant model of spontaneous breast cancer metastasis to multiple sites, including bone, was characterized and used to identify genes involved in metastatic progression. The metastatic potential of several genetically related tumor lines was assayed using a novel real-time quantitative RT-PCR assay of tumor burden. Based on this assay, the tumor lines were categorized as nonmetastatic (67NR), weakly metastatic to lymph node (168FARN) or lung (66cl4), or highly metastatic to lymph node, lung, and bone (4T1.2 and 4T1.13). In vitro assays that mimic stages of metastasis showed that highly metastatic tumors lines were more adhesive, invasive, and migratory than the less metastatic lines. To identify metastasis-related genes in this model, each metastatic tumor was array profiled against the nonmetastatic 67NR using 15,000 mouse cDNA arrays. A significant proportion of genes relating to the extracellular matrix had elevated expression in highly metastatic tumors. The role of one of these genes, POEM, was further investigated in the model. In situ hybridization showed that POEM expression was specific to the tumor epithelium of highly metastatic tumors. Decreased POEM expression in 4T1.2 tumors significantly inhibited spontaneous metastasis to the lung, bone, and kidney. Taken together, our data support a role for the extracellular matrix in metastatic progression and describe, for the first time, a role for POEM in this process. PMID:15671244

  16. A preliminary study on the effects of acellular tissue graft augmentation in acute Achilles tendon ruptures.

    PubMed

    Lee, Daniel K

    2008-01-01

    Acute Achilles tendon rupture injuries present surgical challenges because of the mechanical forces placed on this tendon. The purpose of this study was to evaluate the effectiveness of an acellular human dermal tissue matrix, GraftJacket Matrix (Wright Medical Technology, Inc., Arlington, TN), as an augmentation material in acute Achilles tendon repair. Eleven consecutive patients with acute tendon ruptures were evaluated and followed up (20-31 months). Primary repair was followed by augmentation with the graft sutured circumferentially around the tendon. Patients were placed in an early functional rehabilitation program with postoperative evaluation at 3, 6, and 12 months. Outcome scores were calculated based on the American Orthopaedic Foot and Ankle Society ankle-hindfoot scoring system. At 20-month postoperative follow-up, there have been no cases of rerupture or recurrent pain. The average return-to-activity time was 11.8 +/- 0.75 weeks. These retrospective clinical results suggest that with an acellular human dermal tissue matrix to augment acute Achilles tendon, primary repair offers a desirable return-to-activity time without any rerupture or complications. ACFAS Level of Clinical Evidence: 2c. PMID:18156058

  17. 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.

  18. 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

  19. 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

  20. Acellular Biomaterials: An Evolving Alternative to Cell-Based Therapies

    PubMed Central

    Burdick, Jason A.; Mauck, Robert L.; Gorman, Joseph H.; Gorman, Robert C.

    2014-01-01

    Acellular biomaterials can stimulate the local environment to repair tissues without the regulatory and scientific challenges of cell-based therapies. A greater understanding of the mechanisms of such endogenous tissue repair is furthering the design and application of these biomaterials. We discuss recent progress in acellular materials for tissue repair, using cartilage and cardiac tissues as examples of applications with substantial intrinsic hurdles, but where human translation is now occurring. PMID:23486777

  1. 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.

  2. 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

  3. 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

  4. 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.

  5. Achilles tendon repair with acellular tissue graft augmentation in neglected ruptures.

    PubMed

    Lee, Daniel K

    2007-01-01

    Neglected Achilles tendon rupture injuries present surgical challenges because of the quality and quantity of tendon tissue during repair combined with the magnitude of mechanical forces placed on this tendon. The purpose of this study was to evaluate the effects of an acellular human dermal tissue matrix, GRAFTJACKET, as an augmentation material in neglected Achilles tendon repair. Nine patients with neglected Achilles tendon ruptures were evaluated and followed up for a minimum of 20 months. Primary repair was followed by augmentation with the graft and suturing circumferentially around the tendon. Patients were placed in an early, functional rehabilitation program with postoperative evaluation at 3, 6, and 12 months. Outcome scores were calculated based on the American Orthopaedic Foot and Ankle Society ankle-hindfoot scoring system. At 20 to 30 months postoperative follow-up range, there has been no incidence of re-rupture or recurrent pain. The average return-to-activity time was 15.2 +/- 1.7 weeks. The results from this retrospective clinical series suggest that using an acellular human dermal tissue matrix to augment neglected Achilles tendon rupture primary repair offers desirable return-to-activity time points and viable surgical alternative over previously reported surgical options. PMID:17980842

  6. 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

  7. 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.

  8. Three-dimensional scaffolds of acellular human and porcine lungs for high throughput studies of lung disease and regeneration

    PubMed Central

    Wagner, Darcy E.; Bonenfant, Nicholas R.; Sokocevic, Dino; DeSarno, Michael; Borg, Zachary; Parsons, Charles; Brooks, Elice M.; Platz, Joseph; Khalpey, Zain; Hoganson, David M.; Deng, Bin; Lam, Ying Wai; Oldinski, Rachael A.; Ashikaga, Takamaru; Weiss, Daniel J.

    2014-01-01

    Acellular scaffolds from complex whole organs such as lung are being increasingly studied for ex vivo organ generation and for in vitro studies of cell-extracellular matrix interactions. We have established effective methods for efficient de- and recellularization of large animal and human lungs including techniques which allow multiple small segments (∼1–3cm3) to be excised that retain 3-dimensional lung structure. Coupled with the use of a synthetic pleural coating, cells can be selectively physiologically inoculated via preserved vascular and airway conduits. Inoculated segments can be further sliced for high throughput studies. Further, we demonstrate thermography as a powerful noninvasive technique for monitoring perfusion decellularization and for evaluating preservation of vascular and airway networks following human and porcine lung decellularization. Collectively, these techniques are a significant step forward as they allow high throughput in vitro studies from a single lung or lobe in a more biologically relevant, three-dimensional acellular scaffold. PMID:24411675

  9. Potential of inherent RGD containing silk fibroin-poly (Є-caprolactone) nanofibrous matrix for bone tissue engineering.

    PubMed

    Bhattacharjee, Promita; Kundu, Banani; Naskar, Deboki; Kim, Hae-Won; Bhattacharya, Debasis; Maiti, T K; Kundu, S C

    2016-02-01

    The current study deals with the fabrication and characterization of blended nanofibrous scaffolds of tropical tasar silk fibroin of Antheraea mylitta and poly (Є-caprolactone) to act as an ideal scaffold for bone regeneration. The use of poly (Є-caprolactone) in osteogenesis is well-recognized. At the same time, the osteoconductive nature of the non-mulberry tasar fibroin is also established due to its internal integrin binding peptide RGD (Arg-Gly-Asp) sequences, which enhance cellular interaction and proliferation. Considering that the materials have the required and favorable properties, the blends are formed using an equal volume ratio of fibroin (2 and 4 wt%) and poly (Є-caprolactone) solution (10 wt%) to fabricate nanofibers. The nanofibers possess an average diameter of 152 ± 18 nm (2 % fibroin/PCL) and 175 ± 15 nm (4% fibroin/PCL). The results of Fourier transform infrared spectroscopy substantiates the preservation of the secondary structure of the fibroin in the blends indicating the structural stability of the neo-matrix. With an increase in the fibroin percentage, the hydrophobicity and thermal stability of the matrices as measured from melting temperature Tm (using DSC) decrease, while the mechanical strength is improved. The blended nanofibrous scaffolds are biodegradable, and support the viability and proliferation of human osteoblast-like cells as observed through scanning electron and confocal microscopes. Alkaline phosphatase assay indicates the cell proliferation and the generation of the neo-bone matrix. Taken together, these findings illustrate that the silk-poly (Є-caprolactone) blended nanofibrous scaffolds have an excellent prospect as scaffolding material in bone tissue engineering. PMID:26174955

  10. 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

  11. The Human Umbilical Vein with Wharton's Jelly as an Allogeneic, Acellular Construct for Vocal Fold Restoration

    PubMed Central

    Rodriguez, Maritza L.; McFetridge, Peter S.

    2009-01-01

    This study investigated the potential of the decellularized human umbilical vein (HUV) as an allogeneic, acellular extracellular matrix (ECM) scaffold for engineering the vocal fold lamina propria in vitro. HUV specimens with Wharton's jelly on the abluminal surface were uniformly dissected from native umbilical cords using an automated procedure and subjected to a novel saline-based decellularization treatment for removal of potentially antigenic epitopes. Human vocal fold fibroblasts from primary culture were seeded onto the resulting acellular constructs and cultured for 21 days. The structures of decellularized and fibroblast-repopulated HUV constructs and the attachment, proliferation, and infiltration of fibroblasts were examined with light microscopy and scanning electron microscopy. Changes in the relative densities of collagen in the constructs associated with decellularization and recellularization were quantified using digital image analysis. In addition, fibroblasts infiltrating the scaffolds were released by cell recovery and quantified by counting. Viscoelastic properties of the scaffolds were measured using a linear, simple-shear rheometer at phonatory frequencies. Results showed that an acellular ECM construct with an intact three-dimensional structure of Wharton's jelly was fabricated. Vocal fold fibroblasts readily attached on the abluminal surface of the construct with high viability, with significant cellular infiltration up to approximately 600 μm deep into the construct. A significant increase in collagen expression was observed with recellularization. The elastic modulus and dynamic viscosity of the fibroblast-repopulated scaffolds were comparable to those of the human vocal fold lamina propria. These findings supported the potential of the construct as a possible surgical allograft for vocal fold restoration and reconstruction. PMID:19456236

  12. 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

  13. 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.

  14. 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.

  15. Confocal Laser Scanning Microscopy Evaluation of an Acellular Dermis Tissue Transplant (Epiflex®)

    PubMed Central

    Hohenberger, Peter

    2012-01-01

    The structure of a biological scaffold is a major determinant of its biological characteristics and its interaction with cells. An acellular dermis tissue transplant must undergo a series of processing steps, to remove cells and genetic material and provide the sterility required for surgical use. During manufacturing and sterilization the structure and composition of tissue transplants may change. The composition of the human cell-free dermis transplant Epiflex® was investigated with specific attention paid to its structure, matrix composition, cellular content and biomechanics. We demonstrated that after processing, the structure of Epiflex remains almost unchanged with an intact collagen network and extracellular matrix (ECM) protein composition providing natural cell interactions. Although the ready to use transplant does contain some cellular and DNA debris, the processing procedure results in a total destruction of cells and active DNA which is a requirement for an immunologically inert and biologically safe substrate. Its biomechanical parameters do not change significantly during the processing. PMID:23056225

  16. 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.

  17. 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

  18. 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

  19. Improving interfacial adhesion with epoxy matrix using hybridized carbon nanofibers containing calcium phosphate nanoparticles for bone repairing.

    PubMed

    Gao, Xukang; Lan, Jinle; Jia, Xiaolong; Cai, Qing; Yang, Xiaoping

    2016-04-01

    Hybridized carbon nanofibers containing calcium phosphate nanoparticles (CNF/CaP) were investigated as osteocompatible nanofillers for epoxy resin. The CNF/CaP was produced by electrospinning mixture solution of polyacrylonitrile and CaP precursor sol-gel, followed by preoxidation and carbonization. The continuous and long CNF/CaP was ultrasonically chopped, mixed into epoxy resin and thermo-cured. Compared to pure CNFs with similar ultrasonication treatment, the shortened CNF/CaP reinforced composites demonstrated significant enhancement in flexural properties of epoxy composites, benefiting from the improved interfacial adhesion between CNF/CaP and resin matrix. The resulting composites also displayed good biocompatibility and sustained calcium ion release, which categorized them as promising materials for bone repairing. PMID:26838838

  20. GBR using bovine bone matrix and resorbable and nonresorbable membranes. Part 1: histologic results.

    PubMed

    Fugazzotto, Paul A

    2003-08-01

    Ninety sites were treated with either sinus augmentation therapy using only Bio-Oss (31 sites), or extraction socket and ridge augmentation therapy using only Bio-Oss beneath secured resorbable or titanium-reinforced nonresorbable membranes (59 sites). Core biopsies were taken at intervals ranging from 4 to 13 months. The 12 core biopsies taken 12 to 13 months postoperative (five sinus augmentation sites and seven extraction socket/ridge augmentation sites) demonstrated distinct Bio-Oss particles in an average of only 0.13% of the core biopsy volume. Bone regeneration was evident in all specimens. PMID:12956480

  1. 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

  2. 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

  3. 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

  4. Repair of lacerated anterior tibial tendon with acellular tissue graft augmentation.

    PubMed

    DiDomenico, Lawrence A; Blasko, Gregory A; Cane, Laurence; Cross, Davina J

    2012-01-01

    In the present case report, we describe the surgical repair of a complete laceration of the anterior tibial tendon using acellular human dermal tissue matrix. A 17-year-old, elite league hockey player was injured in the locker room when a teammate still clad in ice skates stepped on his bare left foot. After evaluation at a local emergency department, the patient presented to our office the next day for additional evaluation. It was determined that surgery would be performed using acellular tissue graft augmentation, followed by physical therapy. Within 7 weeks of the injury, the athlete returned to his original level of activity. At 3 years of follow-up, he was playing Division 1 hockey at the university level. We believe that augmentation of the tendon repair with the grafting material enhanced the tendon tensile strength and promoted ingrowth through vascular channels. This, combined with the patient's dedication to physical therapy, led to excellent recovery in less time than anticipated. PMID:22762944

  5. 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

  6. Transdifferentiation of Bone Marrow Mesenchymal Stem Cells into the Islet-Like Cells: the Role of Extracellular Matrix Proteins.

    PubMed

    Pokrywczynska, Marta; Lewandowska, Marzena Anna; Krzyzanowska, Sandra; Jundzill, Arkadiusz; Rasmus, Marta; Warda, Karolina; Gagat, Maciej; Deptula, Aleksander; Helmin-Basa, Anna; Holysz, Marcin; Nowacki, Maciej; Buchholz, Lukasz; Bodnar, Magdalena; Marszalek, Andrzej; Grzanka, Alina; Jozwicki, Wojciech; Michalkiewicz, Jacek; Drewa, Tomasz

    2015-10-01

    Pancreatic islet implantation has been recently shown to be an efficient method of treatment for type 1 diabetes. However, limited availability of donor islets reduces its use. Bone morrow would provide potentially unlimited source of stem cells for generation of insulin-producing cells. This study was performed to evaluate the influence of extracellular matrix proteins like collagen, laminin, and vitronectin on bone marrow mesenchymal stem cells (BM-MSCs) transdifferentiation into islet-like cells (ILCs) in vitro. To our knowledge, this is the first report evaluating the importance of vitronectin in transdifferentiation of BM-MSCs into ILCs. Rat BM-MSCs were induced to ILCs using four-step protocol on plates coated with collagen type IV, laminin type I and vitronectin type I. Quantitative real-time PCR was performed to detect gene expression related to pancreatic β cell development. The induced cells expressed islet-related genes including: neurogenin 3, neurogenic differentiation 1, paired box 4, NK homeobox factor 6.1, glucagon, insulin 1 and insulin 2. Laminin but not collagen type IV or vitronectin enhanced expression of insulin and promoted formation of islet-like structures in monolayer culture. Laminin triggered transdifferentiation of BM-MSCs into ILCs. PMID:25957583

  7. 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

  8. A statistical model to allow the phasing out of the animal testing of demineralised bone matrix products.

    PubMed

    Murray, Samuel S; Brochmann, Elsa J; Harker, Judith O; King, Edward; Lollis, Ryan J; Khaliq, Sameer A

    2007-08-01

    Demineralised bone matrix (DBM) products are complex mixtures of proteins known to influence bone growth, turnover, and repair. They are used extensively in orthopaedic surgery, and are bioassayed in vivo prior to being used in clinical applications. Many factors contribute to the osteogenic potency of DBM, but the relative contributions of these factors, as well as the possibility of interactive effects, are not completely defined. The "gold standard" measure of the therapeutic value of DBM, the in vivo assay for ectopic bone formation, is costly, time-consuming, and involves the use of numerous animal subjects. We have measured the levels of five growth factors released by the collagenase digestion of DBM, and statistically related these levels with osteogenic potency as determined by a standard in vivo model, in order to determine which value or combination of values of growth factors best predict osteogenic activity. We conclude that the level of BMP-2 is the best single predictor of osteogenic potency, and that adding the values of other growth factors only minimally increases the predictive power of the BMP-2 measurement. A small, but significant, interactive effect between BMP-2 and BMP-7 was demonstrated. We present a statistical model based on growth factor (e.g. BMP-2) analysis that best predicts the in vivo assay score for DBM. This model allows the investigator to predict which lots of DBM are likely to exhibit in vivo bioactivity and which are not, thus reducing the need to conduct in vivo testing of insufficiently active lots of DBM. This model uses cut-point analysis to allow the user to assign an estimate of acceptable uncertainty with respect to the "gold standard" test. This procedure will significantly reduce the number of animal subjects used to test DBM products. PMID:17850186

  9. 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

  10. Dietary Zinc Reduces Osteoclast Resorption Activities and Increases Markers of Osteoblast Differentiation, Matrix Maturation, and Mineralization in the Long Bones of Growing Rats

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The nutritional influence of zinc (Zn) on markers of bone extracellular matrix (ECM) resorption and mineralization was investigated in growing rats. Thirty male weanling rats were randomly assigned to consume AIN-93G based diets containing 2.5, 5, 7.5, 15, or 30 µg Zn/g diet for 24 d. Femur Zn incre...

  11. Comparison of osteoclastogenesis and resorption activity of human osteoclasts on tissue culture polystyrene and on natural extracellular bone matrix in 2D and 3D.

    PubMed

    Kleinhans, C; Schmid, F F; Schmid, F V; Kluger, P J

    2015-07-10

    Bone homeostasis is maintained by osteoblasts (bone formation) and osteoclasts (bone resorption). While there have been numerous studies investigating mesenchymal stem cells and their potential to differentiate into osteoblasts as well as their interaction with different bone substitute materials, there is only limited knowledge concerning in vitro generated osteoclasts. Due to the increasing development of degradable bone-grafting materials and the need of sophisticated in vitro test methods, it is essential to gain deeper insight into the process of osteoclastogenesis and the resorption functionality of human osteoclasts. Therefore, we focused on the comparison of osteoclastogenesis and resorption activity on tissue culture polystyrene (TCPS) and bovine extracellular bone matrices (BMs). Cortical bone slices were used as two-dimensional (2D) substrates, whereas a thermally treated cancellous bone matrix was used for three-dimensional (3D) experiments. We isolated primary human monocytes and induced osteoclastogenesis by medium supplementation. Subsequently, the expression of the vitronectin receptor (αVβ3) and cathepsin K as well as the characteristic actin formation on TCPS and the two BMs were examined. The cell area of human osteoclasts was analyzed on TCPS and on BMs, whereas significantly larger osteoclasts could be detected on BMs. Additionally, we compared the diameter of the sealing zones with the measured diameter of the resorption pits on the BMs and revealed similar diameters of the sealing zones and the resorption pits. We conclude that using TCPS as culture substrate does not affect the expression of osteoclast-specific markers. The analysis of resorption activity can successfully be conducted on cortical as well as on cancellous bone matrices. For new in vitro test systems concerning bone resorption, we suggest the establishment of a 2D assay for high throughput screening of new degradable bone substitute materials with osteoclasts. PMID:25562421

  12. 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

  13. 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

  14. 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

  15. A comparative study of acellular nerve xenografts and allografts in repairing rat facial nerve defects.

    PubMed

    Huang, Haitao; Xiao, Hongxi; Liu, Huawei; Niu, Yu; Yan, Rongzeng; Hu, Min

    2015-10-01

    Acellular nerves are composed of a basal lamina tube, which retains sufficient bioactivity to promote axon regeneration, thereby repairing peripheral nerve gaps. However, the clinical application of acellular allografts has been restricted due to its limited availability. To investigate whether xenografts, a substitute to allograft acellular nerves in abundant supply, could efficiently promote nerve regeneration, rabbit and rat acellular nerve grafts were used to reconstruct 1 cm defects in Wistar rat facial nerves. Autologous peroneal nerve grafts served as a positive control group. A total of 12 weeks following the surgical procedure, the axon number, myelinated axon number, myelin sheath thickness, and nerve conduction velocity of the rabbit and rat‑derived acellular nerve grafts were similar, whereas the fiber diameter of the rabbit‑derived acellular xenografts decreased, as compared with those of rat‑derived acellular allografts. Autografts exerted superior effects on nerve regeneration; however, no significant difference was observed between the axon number in the autograft group, as compared with the two acellular groups. These results suggested that autografts perform better than acellular nerve grafts, and chemically extracted acellular allografts and xenografts have similar effects on the regeneration of short facial nerve defects. PMID:26239906

  16. 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

  17. 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

  18. Cross-Talk Between Human Tenocytes and Bone Marrow Stromal Cells Potentiates Extracellular Matrix Remodeling In Vitro

    PubMed Central

    Ekwueme, Emmanuel C.; Shah, Jay V.; Mohiuddin, Mahir; Ghebes, Corina A.; Crispim, João F.; Saris, Daniël B.F.; Fernandes, Hugo A.M.; Freeman, Joseph W.

    2016-01-01

    Tendon and ligament (T/L) pathologies account for a significant portion of musculoskeletal injuries and disorders. Tissue engineering has emerged as a promising solution in the regeneration of both tissues. Specifically, the use of multipotent human mesenchymal stromal cells (hMSC) has shown great promise to serve as both a suitable cell source for tenogenic regeneration and a source of trophic factors to induce tenogenesis. Using four donor sets, we investigated the bidirectional paracrine tenogenic response between human hamstring tenocytes (hHT) and bone marrow-derived hMSC. Cell metabolic assays showed that only one hHT donor experienced sustained notable increases in cell metabolic activity during co-culture. Histological staining confirmed that co-culture induced elevated collagen protein levels in both cell types at varying time-points in two of four donor sets assessed. Gene expression analysis using qPCR showed the varied up-regulation of anabolic and catabolic markers involved in extracellular matrix maintenance for hMSC and hHT. Furthermore, analysis of hMSC/hHT co-culture secretome using a reporter cell line for TGF-β, a potent inducer of tenogenesis, revealed a trend of higher TGF-β bioactivity in hMSC secretome compared to hHT. Finally, hHT cytoskeletal immunostaining confirmed that both cell types released soluble factors capable of inducing favorable tenogenic morphology, comparable to control levels of soluble TGF-β1. These results suggest a potential for TGF-β-mediated signaling mechanism that is involved during the paracrine interplay between the two cell types that is reminiscent of T/L matrix remodeling/ turnover. These findings have significant implications in the clinical use of hMSC for common T/L pathologies. PMID:26308651

  19. 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

  20. 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

  1. 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

  2. Bone Mineral 31P and Matrix-Bound Water Densities Measured by Solid-State 1H and 31P MRI

    PubMed Central

    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.

    2014-01-01

    Bone is a composite material consisting of mineral and hydrated collagen fractions. MRI of bone is challenging due to 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, ages 27-97 years, were acquired by zero-echo-time 31P and 1H 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-CT, and apparent mineral density by pQCT. MRI-derived densities were compared to x-ray-based measurements by least-squares regression. Mean bone mineral 31P density was 6.74±1.22 mol/L (corresponding to 1129±204 mg/cc mineral), and mean bound water 1H density was 31.3±4.2 mol/L (corresponding to 28.3±3.7 %v/v). Both 31P and bound water (BW) densities were correlated negatively with porosity (31P: R2 = 0.32, p < 0.005; BW: R2 = 0.63, p < 0.0005) and age (31P: R2 = 0.39, p < 0.05; BW: R2 = 0.70, p < 0.0001), and positively with pQCT density (31P: R2 = 0.46, p < 0.05; BW: R2 = 0.50, p < 0.005). In contrast, the bone mineralization ratio (expressed here as the ratio of 31P 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 water densities using clinical hardware. PMID:24846186

  3. 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

  4. 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

  5. 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

  6. Ligament reconstruction with tendon interposition using an acellular dermal allograft for thumb carpometacarpal arthritis.

    PubMed

    Kokkalis, Zinon T; Zanaros, George; Sotereanos, Dean G

    2009-03-01

    Ligament reconstruction tendon interposition arthroplasty is currently the preferred technique for carpometacarpal joint arthritis of the thumb by most surgeons. Despite its efficacy, morbidity has been associated with the harvest of the flexor carpi radialis tendon. Using an allograft as material for arthroplasty, donor site morbidity is avoided. In this report, we present our surgical technique to perform ligament reconstruction tendon interposition arthroplasty using an acellular dermal matrix allograft (GraftJacket) in patients with Eaton stages II, III, and IV symptomatic first carpometacarpal arthritis.One hundred thumbs with trapeziometacarpal osteoarthritis underwent surgical treatment using GraftJacket allograft instead of the flexor carpi radialis tendon autograft. Each patient was followed for a minimum of 12 months. The surgical procedure included trapezial excision and identification of the flexor carpi radialis. The allograft was cut to create a 15-cm strip. The ligament reconstruction was performed by passing the strip around the flexor carpi radialis tendon and suturing it to the base of the thumb metacarpal base through an intramedullary drill hole. The remaining portion of the allograft was fashioned as an interposition mass (anchovy) and interposed between the scaphoid and the base of the first metacarpal.All but 1 patient experienced significant improvement in his or her pain scale rating and grip and pinch strengths. Outcomes from this study compare very favorably with those of other series. No patients experienced a foreign body reaction or infection in this series. We believe that the use of an acellular dermal allograft for both ligament reconstruction and tendon interposition provides a safe and an effective alternative technique for the treatment of advanced first carpometacarpal arthritis. PMID:19276927

  7. 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

  8. Effect of dynamic seeding methods on the distribution of fibroblasts within human acellular dermis.

    PubMed

    Vitacolonna, Mario; Belharazem, Djeda; Hohenberger, Peter; Roessner, Eric D

    2015-12-01

    The purpose of this investigation was to compare different dynamic cell seeding methods regarding their seeding efficiency, homogeneity, infiltration depth and proliferation within a human acellular dermis. In addition, the growth behaviour was observed during a 12-day static in vitro culture. The dynamic methods included orbital-shaker seeding and the use of a plate centrifuge with different rotational speeds, combinations of low-pressure for matrix degassing and centrifugal seeding. Scaffolds were incubated for up to 12 days statically. Cell distribution and infiltration depth were analysed histologically at days 0, 4, 8 and 12. Seeding efficiency and cell proliferation were quantified with the MTT-assay at the same time points. Centrifugal seeding with 300g for 5 × 1 min combined with matrix degassing significantly increased the seeding efficiency and homogeneity compared to the other methods. However, following static culture, no cells were detectable after 4 days in the inner matrix zones. Furthermore, none of the degassing+centrifugation groups reached a significantly higher proliferation at day 8 compared to the reference. The use of a single dynamic method resulted in an inefficient cell seeding. We archived the highest seeding efficiency, homogeneity and infiltration depth using a combination of degassing+centrifugation at 300g for 5 × 1 min. PMID:25795264

  9. Muscle acellular scaffold as a biomaterial: effects on C2C12 cell differentiation and interaction with the murine host environment

    PubMed Central

    Perniconi, Barbara; Coletti, Dario; Aulino, Paola; Costa, Alessandra; Aprile, Paola; Santacroce, Luigi; Chiaravalloti, Ernesto; Coquelin, Laura; Chevallier, Nathalie; Teodori, Laura; Adamo, Sergio; Marrelli, Massimo; Tatullo, Marco

    2014-01-01

    The extracellular matrix (ECM) of decellularized organs possesses the characteristics of the ideal tissue-engineering scaffold (i.e., histocompatibility, porosity, degradability, non-toxicity). We previously observed that the muscle acellular scaffold (MAS) is a pro-myogenic environment in vivo. In order to determine whether MAS, which is basically muscle ECM, behaves as a myogenic environment, regardless of its location, we analyzed MAS interaction with both muscle and non-muscle cells and tissues, to assess the effects of MAS on cell differentiation. Bone morphogenetic protein treatment of C2C12 cells cultured within MAS induced osteogenic differentiation in vitro, thus suggesting that MAS does not irreversibly commit cells to myogenesis. In vivo MAS supported formation of nascent muscle fibers when replacing a muscle (orthotopic position). However, heterotopically grafted MAS did not give rise to muscle fibers when transplanted within the renal capsule. Also, no muscle formation was observed when MAS was transplanted under the xiphoid process, in spite of the abundant presence of cells migrating along the laminin-based MAS structure. Taken together, our results suggest that MAS itself is not sufficient to induce myogenic differentiation. It is likely that the pro-myogenic environment of MAS is not strictly related to the intrinsic properties of the muscle scaffold (e.g., specific muscle ECM proteins). Indeed, it is more likely that myogenic stem cells colonizing MAS recognize a muscle environment that ultimately allows terminal myogenic differentiation. In conclusion, MAS may represent a suitable environment for muscle and non-muscle 3D constructs characterized by a highly organized structure whose relative stability promotes integration with the surrounding tissues. Our work highlights the plasticity of MAS, suggesting that it may be possible to consider MAS for a wider range of tissue engineering applications than the mere replacement of volumetric muscle loss

  10. 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

  11. Chemically extracted acellular allogeneic nerve graft combined with ciliary neurotrophic factor promotes sciatic nerve repair

    PubMed Central

    Zhang, Yanru; Zhang, Hui; Katiella, Kaka; Huang, Wenhua

    2014-01-01

    A chemically extracted acellular allogeneic nerve graft can reduce postoperative immune rejection, similar to an autologous nerve graft, and can guide neural regeneration. However, it remains poorly understood whether a chemically extracted acellular allogeneic nerve graft combined with neurotrophic factors provides a good local environment for neural regeneration. This study investigated the repair of injured rat sciatic nerve using a chemically extracted acellular allogeneic nerve graft combined with ciliary neurotrophic factor. An autologous nerve anastomosis group and a chemical acellular allogeneic nerve bridging group were prepared as controls. At 8 weeks after repair, sciatic functional index, evoked potential amplitude of the soleus muscle, triceps wet weight recovery rate, total number of myelinated nerve fibers and myelin sheath thickness were measured. For these indices, values in the three groups showed the autologous nerve anastomosis group > chemically extracted acellular nerve graft + ciliary neurotrophic factor group > chemical acellular allogeneic nerve bridging group. These results suggest that chemically extracted acellular nerve grafts combined with ciliary neurotrophic factor can repair sciatic nerve defects, and that this repair is inferior to autologous nerve anastomosis, but superior to chemically extracted acellular allogeneic nerve bridging alone. PMID:25221592

  12. Chemically extracted acellular allogeneic nerve graft combined with ciliary neurotrophic factor promotes sciatic nerve repair.

    PubMed

    Zhang, Yanru; Zhang, Hui; Katiella, Kaka; Huang, Wenhua

    2014-07-15

    A chemically extracted acellular allogeneic nerve graft can reduce postoperative immune rejection, similar to an autologous nerve graft, and can guide neural regeneration. However, it remains poorly understood whether a chemically extracted acellular allogeneic nerve graft combined with neurotrophic factors provides a good local environment for neural regeneration. This study investigated the repair of injured rat sciatic nerve using a chemically extracted acellular allogeneic nerve graft combined with ciliary neurotrophic factor. An autologous nerve anastomosis group and a chemical acellular allogeneic nerve bridging group were prepared as controls. At 8 weeks after repair, sciatic functional index, evoked potential amplitude of the soleus muscle, triceps wet weight recovery rate, total number of myelinated nerve fibers and myelin sheath thickness were measured. For these indices, values in the three groups showed the autologous nerve anastomosis group > chemically extracted acellular nerve graft + ciliary neurotrophic factor group > chemical acellular allogeneic nerve bridging group. These results suggest that chemically extracted acellular nerve grafts combined with ciliary neurotrophic factor can repair sciatic nerve defects, and that this repair is inferior to autologous nerve anastomosis, but superior to chemically extracted acellular allogeneic nerve bridging alone. PMID:25221592

  13. Contribution of human osteoblasts and macrophages to bone matrix degradation and proinflammatory cytokine release after exposure to abrasive endoprosthetic wear particles.

    PubMed

    Jonitz-Heincke, Anika; Lochner, Katrin; Schulze, Christoph; Pohle, Diana; Pustlauk, Wera; Hansmann, Doris; Bader, Rainer

    2016-08-01

    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

  14. 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

  15. 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. PMID:26051141

  16. 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

  17. Maxillary sinus floor augmentation on humans: Packing simulations and 8 months histomorphometric comparative study of anorganic bone matrix and β-tricalcium phosphate particles as grafting materials

    PubMed Central

    Martinez, A.; Franco, J.; Saiz, E.; Guitian, F.

    2011-01-01

    The present study compares the behaviour of an anorganic bone matrix material and a synthetic β-Tricalcium phosphate employed as grafting materials in a sinus floor augmentation two step protocol in humans. In order to estimate the initial occupation level for the two materials, an ‘in vitro’ simulation has been performed to analyse macroporosity created due to particle packing in terms of porosity and interparticle distances. Grafting in the sinus floor augmentation was performed by filling the defects only with pure grafting materials without autogenous bone addition. The new-bone generated is 100% based on the osteoconductive properties of the grafted materials in contact with physiological fluids. The implants were placed 8 months after the grafting procedure. All the implanted positions were biopsied and embedded in methacrylate resin. Histomorphometric analyses were done over thin film undecalcified sections. Packing simulations allow establishing a comparison of the resorbed volumes related to the initial occupancy of the grafting materials inside the defect. The nature of this interconnected pore network is very alike for either material so new-bone generated was similar (~35 vol.%). PMID:21625341

  18. Exposed tibial bone after burns: Flap reconstruction versus dermal substitute.

    PubMed

    Verbelen, Jozef; Hoeksema, Henk; Pirayesh, Ali; Van Landuyt, Koenraad; Monstrey, Stan

    2016-03-01

    A 44 years old male patient had suffered extensive 3rd degree burns on both legs, undergoing thorough surgical debridement, resulting in both tibias being exposed. Approximately 5 months after the incident he was referred to the Department of Plastic and Reconstructive Surgery of the University Hospital Gent, Belgium, to undergo flap reconstruction. Free flap surgery was performed twice on both lower legs but failed on all four occasions. In between flap surgery, a dermal substitute (Integra(®)) was applied, attempting to cover the exposed tibias with a layer of soft tissue, but also without success. In order to promote the development of granulation tissue over the exposed bone, small holes were drilled in both tibias with removal of the outer layer of the anterior cortex causing the bone to bleed and subsequently negative pressure wound therapy (NPWT) was applied. The limited granulation tissue resulting from this procedure was then covered with a dermal substitute (Glyaderm(®)), consisting of acellular human dermis with an average thickness of 0.25mm. This dermal substitute was combined with a NPWT-dressing, and then served as an extracellular matrix (ECM), guiding the distribution of granulation tissue over the remaining areas of exposed tibial bone. Four days after initial application of Glyaderm(®) combined with NPWT both tibias were almost completely covered with a thin coating of soft tissue. In order to increase the thickness of this soft tissue cover two additional layers of Glyaderm(®) were applied at intervals of approximately 1 week. One week after the last Glyaderm(®) application both wounds were autografted. The combination of an acellular dermal substitute (Glyaderm(®)) with negative pressure wound therapy and skin grafting proved to be an efficient technique to cover a wider area of exposed tibial bone in a patient who was not a candidate for free flap surgery. An overview is also provided of newer and simpler techniques for coverage of

  19. Purification of matrix Gla protein from a marine teleost fish, Argyrosomus regius: calcified cartilage and not bone as the primary site of MGP accumulation in fish.

    PubMed

    Simes, D C; Williamson, M K; Ortiz-Delgado, J B; Viegas, C S B; Price, P A; Cancela, M L

    2003-02-01

    Matrix Gla protein (MGP) belongs to the family of vitamin K-dependent, Gla-containing proteins, and in mammals, birds, and Xenopus, its mRNA was previously detected in extracts of bone, cartilage, and soft tissues (mainly heart and kidney), whereas the protein was found to accumulate mainly in bone. However, at that time, it was not evaluated if this accumulation originated from protein synthesized in cartilage or in bone cells because both coexist in skeletal structures of higher vertebrates and Xenopus. Later reports showed that MGP also accumulated in costal calcified cartilage as well as at sites of heart valves and arterial calcification. Interestingly, MGP was also found to accumulate in vertebra of shark, a cartilaginous fish. However, to date, no information is available on sites of MGP expression or accumulation in teleost fishes, the ancestors of terrestrial vertebrates, who have in their skeleton mineralized structures with both bone and calcified cartilage. To analyze MGP structure and function in bony fish, MGP was acid-extracted from the mineralized matrix of either bone tissue (vertebra) or calcified cartilage (branchial arches) from the bony fish, Argyrosomus regius, separated from the mineral phase by dialysis, and purified by Sephacryl S-100 chromatography. No MGP was recovered from bone tissue, whereas a protein peak corresponding to the MGP position in this type of gel filtration was obtained from an extract of branchial arches, rich in calcified cartilage. MGP was identified by N-terminal amino acid sequence analysis, and the resulting protein sequence was used to design specific oligonucleotides suitable to amplify the corresponding DNA by a mixture of reverse transcription-polymerase chain reaction (RT-PCR) and 5'rapid amplification of cDNA (RACE)-PCR. In parallel, ArBGP (bone Gla protein, osteocalcin) was also identified in the same fish, and its complementary DNA cloned by an identical procedure. Tissue distribution/accumulation was

  20. 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

  1. Homogenous demineralized dentin matrix and platelet-rich plasma for bone tissue engineering in cranioplasty of diabetic rabbits: biochemical, radiographic, and histological analysis.

    PubMed

    Gomes, M F; Valva, V N; Vieira, E M M; Giannasi, L C; Salgado, M A C; Vilela-Goulart, M G

    2016-02-01

    This study evaluated the effects of homogenous demineralized dentin matrix (HDDM) slices and platelet-rich plasma (PRP) in surgical defects created in the parietal bones of alloxan-induced diabetic rabbits, treated with a guided bone regeneration technique. Biochemical, radiographic, and histological analyses were performed. Sixty adult New Zealand rabbits were divided into five groups of 12: normoglycaemic (control, C), diabetic (D), diabetic with a PTFE membrane (DM), diabetic with a PTFE membrane and HDDM slices (DM-HDDM), and diabetic with PTFE membrane and PRP (DM-PRP). The quantity and quality of bone mass was greatest in the DM-HDDM group (respective radiographic and histological analyses: at 15 days, 71.70 ± 16.50 and 50.80 ± 1.52; 30 days, 62.73 ± 16.51 and 54.20 ± 1.23; 60 days, 63.03 ± 11.04 and 59.91 ± 3.32; 90 days, 103.60 ± 24.86 and 78.99 ± 1.34), followed by the DM-PRP group (respective radiographic and histological analyses: at 15 days 23.00 ± 2.74 and 20.66 ± 7.45; 30 days 31.92 ± 6.06 and 25.31 ± 5.59; 60 days 25.29 ± 16.30 and 46.73 ± 2.07; 90 days 38.10 ± 14.04 and 53.38 ± 9.20). PRP greatly enhanced vascularization during the bone repair process. Abnormal calcium metabolism was statistically significant in the DM-PRP group (P<0.001) for all four time intervals studied, especially when compared to the DM-HDDM group. Alkaline phosphatase activity was significantly higher in the DM-HDDM group (P<0.001) in comparison to the C, D, and DM-PRP groups, confirming the findings of intense osteoblastic activity and increased bone mineralization. Thus, HDDM promoted superior bone architectural microstructure in bone defects in diabetic rabbits due to its effective osteoinductive and osteoconductive activity, whereas PRP stimulated angiogenesis and red bone marrow formation. PMID:26482638

  2. 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

  3. 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. PMID:27060915

  4. Functional bone histology of zebrafish reveals two types of endochondral ossification, different types of osteoblast clusters and a new bone type.

    PubMed

    Weigele, Jochen; Franz-Odendaal, Tamara A

    2016-07-01

    The zebrafish is as an important vertebrate animal model system for studying developmental processes, gene functions and signalling pathways. It is also used as a model system for the understanding of human developmental diseases including those related to the skeleton. However, surprisingly little is known about normal zebrafish skeletogenesis and osteogenesis. As in most vertebrates, it is commonly known that the bones of adult zebrafish are cellular unlike that of some other teleosts. After careful histological analyses of each zebrafish adult bone, we identified several acellular bones, with no entrapped osteocytes in addition to several cellular bones. We show that both cellular and acellular bones can even occur within the same skeletal element and transitions between these two cell types can be found. Furthermore, we describe two types of osteoblast clusters during skeletogenesis and two different types of endochondral ossification. The epiphyseal plate, for example, lacks a zone of calcification and a degradation zone with osteoblasts. A new bone type that we term tubular bone was also identified. This bone is completely filled with adipose tissue, unlike spongy bones. This study provides important insight on how osteogenesis takes place in zebrafish, and especially on the transition from cellular to acellular bones. Overall, this study leads to a deeper understanding of the functional histological composition of adult zebrafish bones. PMID:27278890

  5. Matrix-associated autologous chondrocyte transplantation combined with iliac crest bone graft for reconstruction of talus necrosis due to villonodular synovitis.

    PubMed

    Dickschas, Jörg; Welsch, Götz; Strecker, Wolf; Schöffl, Volker

    2012-01-01

    We report the case of a 24-year-old driving instructor with osteonecrosis of the talus and a large articular cartilage and osseous defect. The cystic lesion was caused by villonodular synovitis. After magnetic resonance imaging detection and arthoscopic analysis, the defect was filled with a bone graft, followed by matrix-associated autologous chondrocyte transplantation (MACT) combined with a total synovectomy. In general, lesions similar to the one described in this case are treated using osteochondral autografts, but in our case the osseous defect was too large to perform an osteochondral autograft. Our choice of treatment with an iliac crest bone graft combined with a MACT simultaneously has not yet been published, as far as we know. The patient returned to his former activities of daily living and sport activities, without restrictions or complaints, and with only a slight deficit in range of motion. Morphological and biochemical magnetic resonance imaging 12 months after surgery showed excellent bone healing with no intraosseous edema. The MACT resulted in a good clinical outcome, with 100% defect filling and excellent integration and surface and signal intensity of the cartilage repair tissue, and the American Orthopaedic Foot and Ankle Society Ankle-Hindfoot score increased from 47 to 79 points. PMID:22104171

  6. Micro-anatomical response of cartilage-on-bone to compression: mechanisms of deformation within and beyond the directly loaded matrix

    PubMed Central

    Thambyah, Ashvin; Broom, Neil

    2006-01-01

    The biomechanical function of articular cartilage relies crucially on its integration with both the subchondral bone and the wider continuum of cartilage beyond the directly loaded contact region. This study was aimed at visualizing, at the microanatomical level, the deformation response of cartilage including that of the non-directly loaded continuum. Cartilage-on-bone samples from bovine patellae were loaded in static compression until a near-equilibrium deformation was achieved, and then chemically fixed in this deformed state. Full-depth cartilage–bone sections, incorporating the indentation profile and beyond, were studied in their fully hydrated state using differential interference contrast microscopy. Morphometric measurements of the indented profile were used in combination with a force analysis of the tangential layer to investigate the extent to which the applied force is attenuated in moving away from the directly loaded region. This study provides microscopic evidence of a structure-related response in the transitional zone of the cartilage matrix. It is manifested as an intense chevron-type shear discontinuity arising from the constraints provided by both the strain-limiting articular surface and the osteochondral attachment. The discontinuity persists well into the non-directly loaded continuum of cartilage and is proposed as a force attenuation mechanism. The structural and biomechanical analyses presented in this study emphasize the important role of the complex microanatomy of cartilage, highlighting the interconnectivity and optimal recruitment of the load-bearing elements throughout the zonally differentiated cartilage depth. PMID:17062019

  7. Decellularization of porcine skeletal muscle extracellular matrix for the formulation of a matrix hydrogel: a preliminary study.

    PubMed

    Fu, Yuehe; Fan, Xuejiao; Tian, Chunxiang; Luo, Jingcong; Zhang, Yi; Deng, Li; Qin, Tingwu; Lv, Qing

    2016-04-01

    Extracellular matrix (ECM) hydrogels are used as scaffolds to facilitate the repair and reconstruction of tissues. This study aimed to optimize the decellularization process of porcine skeletal muscle ECM and to formulate a matrix hydrogel scaffold. Five multi-step methods (methods A-E) were used to generate acellular ECM from porcine skeletal muscle [rinsing in SDS, trypsin, ethylenediaminetetraacetic acid (EDTA), Triton X-100 and/or sodium deoxycholate at 4-37°C]. The resulting ECM was evaluated using haematoxylin and eosin, 4-6-diamidino-2-phenylindole (DAPI) staining, and DNA quantification. Acellular matrix was dissolved in pepsin and gelled at 37°C. Hydrogel response to temperature was observed in vivo and in vitro. ECM components were assessed by Masson, Sirius red, and alcian blue staining, and total protein content. Acellular porcine skeletal muscle exhibited a uniform translucent white appearance. No intact nuclear residue was detected by haematoxylin and eosin staining, while DAPI staining showed a few nuclei in the matrixes produced by methods B, C, and D. Method A generated a gel that was too thin for gelation. However, the matrix obtained by rinsing in 0.2% trypsin/0.1% EDTA, 0.5% Triton X-100, and 1% Triton X-100/0.2% sodium deoxycholate was nuclei-free and produced a viscous solution that formed a structurally stable white jelly-like hydrogel. The residual DNA content of this solution was 49.37 ± 0.72 ng/mg, significantly less than in fresh skeletal muscle, and decreased to 19.22 ± 0.85 ng/mg after gelation (P < 0.05). The acellular matrix was rich in collagen and glycosaminoglycan, with a total protein concentration of 64.8 ± 6.9%. An acellular ECM hydrogel from porcine skeletal muscle was efficiently produced. PMID:26781342

  8. Schwann-like cells seeded in acellular nerve grafts improve nerve regeneration

    PubMed Central

    2014-01-01

    Background This study evaluated whether Schwann-like cells (SLCs) induced from bone marrow-derived mesenchymal stem cells (BM-MSCs) transplanted into acellular nerve grafts (ANGs) could repair nerve defects compared with nerve isografts and ANGs with BM-MSCs. Methods BM-MSCs extracted, separated and purified from the bone marrow of rats, and some of the BM-MSCs were cultured with mixed induction agents that could induce BM-MSCs into SLCs. Either SLCs or BM-MSCs were seeded onto 10-mm ANGs, and the isografts were chosen as the control. The walking-track test, tibialis anterior muscle weight measurement, electrophysiological examination, toluidine blue staining, transmission electron micrographs and immunostaining of S-100 and VEGF in these three groups were evaluated in a 10-mm rat sciatic injury-repair model. Results The walking-track test, tibialis anterior muscle weight measurement and electrophysiological examination of the sciatic nerve suggested the groups of ANGs with SLCs and isografts obtained better results than the BM-MSC group (P < 0.05). Meanwhile, the results of the SLCs and isograft groups were similar (P > 0.05). All the histomorphometric analyses (toluidine blue staining, transmission electron micrographs and immunostaining of S-100 and VEGF) showed that there were more regenerating nerve fibers in the group of ANGs with SLCs than the BM-MSCs (P < 0.05), but there was no significant difference between the SLC and isograft groups (P > 0.05). Conclusions SLCs seeded in ANGs and isografts show better functional regeneration compared with BM-MSCs seeded in ANGs. Additionally, SLCs combined with ANGs present almost the same outcome as the isografts. Therefore, SLCs with ANGs can be a good choice in nerve defect repairs. PMID:24885337

  9. Evaluation of osteogenic cell differentiation in response to bone morphogenetic protein or demineralized bone matrix in a critical sized defect model using GFP reporter mice.

    PubMed

    Alaee, Farhang; Hong, Seung-Hyun; Dukas, Alex G; Pensak, Michael J; Rowe, David W; Lieberman, Jay R

    2014-09-01

    We evaluated the osteoprogenitor response to rhBMP-2 and DBM in a transgenic mouse critical sized defect. The mice expressed Col3.6GFPtopaz (a pre-osteoblastic marker), Col2.3GFPemerald (an osteoblastic marker) and α-smooth muscle actin (α-SMA-Cherry, a pericyte/myofibroblast marker). We assessed defect healing at various time points using radiographs, frozen, and conventional histologic analyses. GFP signal in regions of interest corresponding to the areas of new bone formation was quantified using a novel computer assisted algorithm. All defects treated with rhBMP-2 healed. In contrast, the majority of the defects in the DBM (27/30) and control (28/30) groups did not heal. Quantitation of pre-osteoblasts demonstrated a maximal response (% GFP + cells/TV) in the Col3.6GFPtopaz mice at day 7 (7.2% ± 6.0, p < 0.05 compared to days 14, 21, 28, and 56). The maximal response of the Col2.3GFP cells was seen at days 14 (8.04% ± 5.0) and 21 (8.31% ± 4.32), p < 0.05. In contrast, DBM and control groups showed a limited osteogenic response at all time points. In conclusion, we demonstrated that the BMP and DBM induce vastly different osteogenic responses which should influence their clinical application as bone graft substitutes. PMID:24888702

  10. 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.

  11. Application of acellular dermis and autograft on burns and scars.

    PubMed

    Ramos Duron, L E; Martínez Pardo, M E; Olivera Zavaleta, V; Silva Diaz, T; Reyes Frías, M L; Luna Zaragoza, D

    1999-01-01

    The cases of two patients with burns treated with dermis allograft and of one patient for lip reconstructive aesthetic filling treated with less than one mm3 of radiosterilised acellular dermis are presented. This paper emphasizes the treatment with radiosterilised dermal grafts with a permanent character so far. Hospitals, therefore, can satisfy the demand for this kind of tissue in the case of disaster and patients with serious injuries. In the cases cited, histocompatibility analysis was not required, thus having the advantage of long-time storage of the radiosterilised dermis used on these patients. Neither inflammatory reaction nor acute phase re-absorption were observed. Moreover, shrink (contract) healing was diminished. After two years, the results are still satisfactory. PMID:10853787

  12. [Bone quantitative ultrasound].

    PubMed

    Matsukawa, Mami

    2016-01-01

    The conventional ultrasonic bone densitometry system can give us information of bone as ultrasonic wave velocity and attenuation. However, the data reflect both structural and material properties of bone. In order to focus only on the bone matrix properties without the effect of bone structure, studies of microscopic Brillouin scattering technique are introduced. The wave velocity in a trabecula was anisotropic and depended on the position and structure of the cancellous bone. The glycation also affected on the wave velocities in bone. As a new bone quality, the piezoelectricity of bone is also discussed. PMID:26728531

  13. 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

  14. [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

  15. 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

  16. Muscle Extracellular Matrix Scaffold Is a Multipotent Environment

    PubMed Central

    Aulino, Paola; Costa, Alessandra; Chiaravalloti, Ernesto; Perniconi, Barbara; Adamo, Sergio; Coletti, Dario; Marrelli, Massimo; Tatullo, Marco; Teodori, Laura

    2015-01-01

    The multipotency of scaffolds is a new concept. Skeletal muscle acellular scaffolds (MAS) implanted at the interface of Tibialis Anterior/tibial bone and masseter muscle/mandible bone in a murine model were colonized by muscle cells near the host muscle and by bone-cartilaginous tissues near the host bone, thus highlighting the importance of the environment in directing cell homing and differentiation. These results unveil the multipotency of MAS and point to the potential of this new technique as a valuable tool in musculo-skeletal tissue regeneration. PMID:25897295

  17. 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. PMID:19825754

  18. Effect of nicotine in matrix mineralization by human bone marrow and Saos-2 cells cultured on the surface of plasma-sprayed titanium implants.

    PubMed

    Pereira, M L; Carvalho, J C; Peres, F; Fernandes, M H

    2009-01-01

    Smoking has an established negative impact in the clinical outcome of dental implants. This work analyses the response of human osteoblastic cells to nicotine, at the surface of plasma-sprayed commercial titanium implants. Human bone marrow (HBM) and Saos-2 cells, seeded on the surface of titanium implants and cultured in experimental conditions favoring osteoblastic differentiation, were exposed continuously to nicotine (0.0001 to 0.5 mg mL(-1)) and characterized for cell proliferation and function. Exposure of HBM cells resulted in increased cell proliferation, higher alkaline phosphatase (ALP) activity, and earlier onset of matrix mineralization at levels up to 0.2 mg mL(-1), an initial inhibitory effect in cell growth and functional activity followed by a recovery in the presence of 0.3 mg mL(-1) and a dose-dependent deleterious effect at higher levels. By contrast, exposure to nicotine did not affect cell proliferation of Saos-2 cells at levels up to 0.2 mg mL(-1), and caused only a small positive effect in ALP activity in the presence of 0.05 and 0.1 mg mL(-1); however, matrix mineralization by Saos-2 cells also occurred earlier in the cultures exposed to levels of nicotine up to 0.1 mg mL(-1). Higher concentrations caused dose-dependent inhibitory effects. Considering the high diffusion potential of nicotine, results suggest a local role of nicotine in modulating bone formation events at the implant surface. PMID:18260147

  19. In vitro and in vivo evaluation of the effects of demineralized bone matrix or calcium sulfate addition to polycaprolactone-bioglass composites.

    PubMed

    Erdemli, O; Captug, O; Bilgili, H; Orhan, D; Tezcaner, A; Keskin, D

    2010-01-01

    The objective of this study was to improve the efficacy of polycaprolactone/bioglass (PCL/BG) bone substitute using demineralized bone matrix (DBM) or calcium sulfate (CS) as a third component. Composite discs involving either DBM or CS were prepared by compression moulding. Bioactivity of discs was evaluated by energy dispersive X-ray spectroscopy (ESCA) and scanning electron microscopy (SEM) following simulated body fluid incubation. The closest Calcium/Phosphate ratio to that of hydroxyl carbonate apatite crystals was observed for PCL/ BG/DBM group (1.53) after 15 day incubation. Addition of fillers increased microhardness and compressive modulus of discs. However, after 4 and 6-week PBS incubations, PCL/BG/DBM discs showed significant decrease in modulus (from 266.23 to 54.04 and 33.45 MPa, respectively) in parallel with its highest water uptakes (36.3 and 34.7%). Discs preserved their integrity with only considerable weight loss (7.5-14.5%) in PCL/BG/DBM group. In vitro cytotoxicity tests showed that all discs were biocompatible. PMID:19756968

  20. 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

  1. Effect of Emdogain enamel matrix derivative and BMP-2 on the gene expression and mineralized nodule formation of alveolar bone proper-derived stem/progenitor cells.

    PubMed

    Fawzy El-Sayed, Karim M; Dörfer, Christof; Ungefroren, Hendrick; Kassem, Neemat; Wiltfang, Jörg; Paris, Sebastian

    2014-07-01

    The objective of this study was to evaluate the effect of Emdogain (Enamel Matrix Derivative, EMD) and Bone Morphogenetic Protein-2 (BMP-2), either solely or in combination, on the gene expression and mineralized nodule formation of alveolar bone proper-derived stem/progenitor cells. Stem/progenitor cells were isolated from human alveolar bone proper, magnetically sorted using STRO-1 antibodies, characterized flowcytometrically for their surface markers' expression, and examined for colony formation and multilineage differentiation potential. Subsequently, cells were treated over three weeks with 100 μg/ml Emdogain (EMD-Group), or 100 ng/ml BMP-2 (BMP-Group), or a combination of 100 ng/ml BMP-2 and 100 μg/ml Emdogain (BMP/EMD-Group). Unstimulated stem/progenitor cells (MACS(+)-Group) and osteoblasts (OB-Group) served as controls. Osteogenic gene expression was analyzed using RTq-PCR after 1, 2 and 3 weeks (N = 3/group). Mineralized nodule formation was evaluated by Alizarin-Red staining. BMP and EMD up-regulated the osteogenic gene expression. The BMP Group showed significantly higher expression of Collagen-I, III, and V, Alkaline phosphatase and Osteonectin compared to MACS(+)- and OB-Group (p < 0.05; Two-way ANOVA/Bonferroni) with no mineralized nodule formation. Under in-vitro conditions, Emdogain and BMP-2 up-regulate the osteogenic gene expression of stem/progenitor cells. The combination of BMP-2 and Emdogain showed no additive effect and would not be recommended for a combined clinical stimulation. PMID:24080138

  2. 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.

  3. 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

  4. Investigation of the Regenerative Capacity of an Acellular Porcine Medial Meniscus for Tissue Engineering Applications

    PubMed Central

    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

  5. 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.

  6. 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

  7. 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

  8. 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

  9. [Experimental, clinical and immunologic assessment of acellular staphylococcal vaccine "Staphylovac"].

    PubMed

    Egorova, N B; Efremova, V N; Kurbatova, E A; Gruber, I M

    2008-01-01

    Results of experimental, clinical and immunological effects of acellular dry staphylococcal vaccine "Staphylovac" developed in Mechnikov Research Institute of Vaccines and Sera are presented. Original mildly virulent strains of Staphylococcus aureus having high immunogenicity, and intra- and interspecies protective activity against different representatives of opportunistic microflora were used for construction of the preparation. Low-toxicity and weak anapylactogenicity of the vaccine were established. In experiments on mice, guinea pigs and rabbits significant protective, antigenic and immunomodulate activity of the preparation was revealed with low sensitization of animals. Clinical trials performed in different centers showed that inclusion of vaccinotherapy in complex treatment of chronic staphylococcal infections (chronic pyodermia, lung abscess etc.) resulted in prolonged pathologic locus, decrease of number and severity of exacerbations, prolongation of remission, and complete recovery in significant number of patients. Activation of innate and adaptive immunity was revealed in the same patients. It was shown on the large group of athletes that administration of the vaccine by aerosol route prevents disruption of immunologic adaptation occurring due to excess physical activity and stress situations during competitions. PMID:19186558

  10. 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.

  11. 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

  12. Potential sites for the perception of gravity in the acellular slime mold Physarum polycephalum

    NASA Astrophysics Data System (ADS)

    Block, I.; Briegleb, W.

    Recently a gravisensitivity of the acellular slime mold Physarum polycephalum, which possesses no specialized gravireceptor, could be established by conducting experiments under simulated and under real near weightlessness. In these experiments macroplasmodia showed a modulation of their contraction rhythm followed by regulation phenomena. Until now the perception mechanism for the gravistimulus is unknown, but several findings indicate the involvement of mitochondria: A) During the impediment of respiration the Og-reaction is inhibited and the regulation is reduced. B) The response to a light stimulus and the following regulation phenomena strongly resemble the behavior during exposure to Og, the only difference is that the two reactions are directed into opposite directions. In the blue-light reaction a flavin of the mitochondrial matrix seems to be involved in the light perception. C) The contraction rhythm as well as its modulations are coupled to rhythmic changes in the levels of ATP and calcium ions, involving the mitochondria as sites of energy production and of Ca++-storage. - So the mitochondria could be the site of the regulation and they possibly are the receptor sites for the light and gravity stimuli. - Also the observation of a morphologic polarity of the slime mold's plasmodial strands has to be considered: Cross-sections reveal that the ectoplasmic wall surrounding the streaming endoplasm is much thinner on the physically lower side than on the upper side of the strand - this applies to strands lying on or hanging on a horizontal surface. So, in addition to the mitochondria, also the morphologic polarity may be involved in the perception mechanism of the observed gravisensitivity and of the recently established geotaxis. - The potential role of the nuclei and of the contractile elements in the perception of gravity is also discussed.

  13. Histologic Characterization of Acellular Dermal Matrices in a Porcine Model of Tissue Expander Breast Reconstruction

    PubMed Central

    Carruthers, Christopher A.; Dearth, Christopher L.; Reing, Janet E.; Kramer, Caroline R.; Gagne, Darcy H.; Crapo, Peter M.; Garcia, Onelio; Badhwar, Amit; Scott, Jeffrey R.

    2015-01-01

    Background: Acellular dermal matrices (ADMs) have been commonly used in expander-based breast reconstruction to provide inferolateral prosthesis coverage. Although the clinical performance of these biologic scaffold materials varies depending on a number of factors, an in-depth systematic characterization of the host response is yet to be performed. The present study evaluates the biochemical composition and structure of two ADMs, AlloDerm® Regenerative Tissue Matrix and AlloMax™ Surgical Graft, and provides a comprehensive spatiotemporal characterization in a porcine model of tissue expander breast reconstruction. Methods: Each ADM was characterized with regard to thickness, permeability, donor nucleic acid content, (residual double-stranded DNA [dsDNA]), and growth factors (basic fibroblast growth factor [bFGF], vascular endothelial growth factor [VEGF], and transforming growth factor-beta 1 [TGF-β1]). Cytocompatibility was evaluated by in vitro cell culture on the ADMs. The host response was evaluated at 4 and 12 weeks at various locations within the ADMs using established metrics of the inflammatory and tissue remodeling response: cell infiltration, multinucleate giant cell formation, extent of ADM remodeling, and neovascularization. Results: AlloMax incorporated more readily with surrounding host tissue as measured by earlier and greater cell infiltration, fewer foreign body giant cells, and faster remodeling of ADM. These findings correlated with the in vitro composition and cytocompatibility analysis, which showed AlloMax to more readily support in vitro cell growth. Conclusions: AlloMax and AlloDerm demonstrated distinct remodeling characteristics in a porcine model of tissue expander breast reconstruction. PMID:24941900

  14. 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

  15. A Prospective Randomized Clinical Trial Comparing Bone Union Rate Following Anterior Cervical Discectomy and Fusion Using a Polyetheretherketone Cage: Hydroxyapatite/B-Tricalcium Phosphate Mixture versus Hydroxyapatite/Demineralized Bone Matrix Mixture

    PubMed Central

    Yi, Jemin; Nam, Woo Dong; Han, Kye Young; Kim, Myung-Ho; Kang, Jong Won; Won, Jonghwa; Kim, Seong Wan; Noh, Won; Yeom, Jin S

    2015-01-01

    Study Design Prospective randomized noninferiority trial. Purpose To evaluate whether the union rate of anterior cervical discectomy and fusion (ACDF) using a polyetheretherketone (PEEK) cage filled with a mixture of hydroxyapatite (HA) and demineralized bone matrix (DBM) is inferior to that of a mixture of β-tricalcium phosphate (β-TCP) and HA. Overview of Literature There have been no clinical trials investigating the outcomes of a mixture of HA and DBM in a PEEK cage in ACDF. Methods Eighty-five eligible patients were randomly assigned to group B (n=43), in which a PEEK cage with a mixture of HA and DBM was used, or group C (n=42), in which a PEEK cage with a mixture of HA and β-TCP was used. The primary study endpoint was the fusion rate, which was assessed with dynamic radiographs and computed tomography (CT) scans. Secondary endpoints included pain intensity using a visual analogue scale, functional outcome using a neck disability index score, laboratory tests of inflammatory profiles, and the infection rate. Results Seventy-seven patients (38 in group B and 39 in group C) were included in the final analysis. One year postoperatively, bone fusion was achieved in 87% of group B patients and 87% of group C patients on dynamic radiographs, and 87% of group B patients and 72% of group C patients on CT scans (p=1.00 and 0.16, respectively). There were also no between-groups differences with respect to the secondary endpoints. Conclusions A HA/DBM mixture inside a PEEK cage can provide noninferior outcomes compared to a HA/TCP mixture in ACDF. PMID:25705332

  16. Characterization of bionanocomposite scaffolds comprised of amine-functionalized single-walled carbon nanotubes crosslinked to an acellular porcine tendon.

    PubMed

    Deeken, Corey R; Cozad, Matthew J; Bachman, Sharon L; Ramshaw, Bruce J; Grant, Sheila A

    2011-03-01

    Carbon nanotubes (CNT) possess many unique electrical and mechanical properties that make them useful for a variety of industrial and biomedical applications. They are especially attractive materials for biomedical applications since their dimensions are similar to components of the extracellular matrix. In this study, amine-functionalized single-walled carbon nanotubes were crosslinked to an acellular porcine diaphragm tendon. The resulting bionanocomposite scaffolds were subjected to a number of materials characterization techniques including a collagenase assay, uniaxial tensile testing, modulated differential scanning calorimetry, and attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy to determine whether the properties of the original extracellular matrix were altered by the treatment processes. A variety of SWCNT concentrations were investigated. While none of the conditions investigated resulted in bionanocomposites with significantly improved physicochemical properties, no detrimental effects were observed due to any of the processing steps. Future studies should be performed to determine if carbon nanotubes can influence cellular adhesion and function in order to promote rapid integration and remodeling. PMID:21254390

  17. Bone Tissue Engineering with Multilayered Scaffolds-Part II: Combining Vascularization with Bone Formation in Critical-Sized Bone Defect.

    PubMed

    Sathy, Binulal Nelson; Watson, Brendan M; Kinard, Lucas A; Spicer, Patrick P; Dahlin, Rebecca L; Mikos, Antonios G; Nair, Shantikumar

    2015-10-01

    Our previous in vivo study showed that multilayered scaffolds made of an angiogenic layer embedded between an osteogenic layer and an osteoconductive layer, with layer thickness in the 100-400 μm range, resulted in through-the-thickness vascularization of the construct even in the absence of exogenous endothelial cells. The angiogenic layer was a collagen-fibronectin gel, and the osteogenic layer was made from nanofibrous polycaprolactone while the osteoconductive layer was made either from microporous hydroxyapatite or microfibrous polycaprolactone. In this follow-up study, we implanted these acellular and cellular multilayered constructs in critical-sized rat calvarial defects and evaluated their vascularization and bone formation potential. Vascularization and bone formation at the defect were evaluated and quantified using microcomputed tomography (microCT) followed by perfusion of the animals with the radio opaque contrast agent, MICROFIL. The extent of bony bridging and union within the critical-sized defect was evaluated using a previously established scoring system from the microCT data set. Similarly the new bone formation in the defect was quantified from the microCT data set as previously reported. Histological evaluation at 4 and 12 weeks validated the microCT findings. Our experimental results showed that acellular multilayered scaffolds with microscale-thick nanofibers and porous ceramic discs with angiogenic zone at their interface can regenerate functional vasculature and bone similar to that of cellular constructs in critical-sized calvarial defects. This result suggests that suitably bioengineered acellular multilayered constructs can be an improved and more translational approach in functional in vivo bone regeneration. PMID:26262560

  18. [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

  19. An acellular dermal matrix allograft (Alloderm®) for increasing keratinized attached gingiva: A case series

    PubMed Central

    Agarwal, Chitra; Kumar, Baron Tarun; Mehta, Dhoom Singh

    2015-01-01

    Context: Adequate amount of keratinized gingiva is necessary to keep gingiva healthy and free of inflammation. Autografts have been used for years with great success to increase the width of attached gingiva. Autografts, however, have the disadvantage of increasing postoperative morbidity and improper color match with the adjacent tissues. Alloderm® allograft has been introduced as an alternative to autografts to overcome these disadvantages. Aim: In this study, the efficacy of alloderm® in increasing the width of attached gingiva and the stability of gained attached gingiva was evaluated clinically. Materials and Methods: Five patients with sites showing inadequate width of attached gingiva (≤1 mm) were enrolled for the study. The width of keratinized gingiva and other clinical parameters were recorded at baseline and 9th month postoperatively. Result: In all cases, there is the average increase of about 2.5 mm of attached gingiva and was maintained for 9-month. Percentage shrinkage of the graft is about 75% at the end of 3rd month in all cases. Excellent colors match with adjacent tissue has been obtained. Conclusion: The study signifies that Alloderm® results in an adequate increase in the amount of attached gingiva and therefore can be used successfully in place of autografts. PMID:26015676

  20. 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

  1. 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

  2. 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

  3. [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

  4. 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

  5. Establishment of a Cytocompatible Cell-Free Intervertebral Disc Matrix for Chondrogenesis with Human Bone Marrow-Derived Mesenchymal Stromal Cells.

    PubMed

    Huang, Zhao; Kohl, Benjamin; Kokozidou, Maria; Arens, Stephan; Schulze-Tanzil, Gundula

    2016-01-01

    Tissue-engineered intervertebral discs (IVDs) utilizing decellularized extracellular matrix (ECM) could be an option for the reconstruction of impaired IVDs due to degeneration or injury. The objective of this study was to prepare a cell-free decellularized human IVD scaffold and to compare neotissue formation in response to recellularization with human IVD cells (hIVDCs) or human bone marrow-derived (hBM) mesenchymal stromal cells (MSCs). IVDs were decellularized via freeze-thaw cycles, detergents and trypsin. Histological staining was performed to monitor cell removal and glycosaminoglycan (GAG) removal. The decellularized IVD was preconditioned using bovine serum albumin and fetal bovine serum before its cytocompatibility for dynamically cultured hBM-MSCs (chondrogenically induced or not) and hIVDCs was compared after 14 days. In addition, DNA, total collagen and GAG contents were assessed. The decellularization protocol achieved maximal cell removal, with only few remaining cell nuclei compared with native tissue, and low toxicity. The DNA content was significantly higher in scaffolds seeded with hIVDCs compared with native IVDs, cell-free and hBM-MSC-seeded scaffolds (p < 0.01). The GAG content in the native tissue was significantly higher compared to the others groups except for the scaffolds reseeded with chondrogenically induced hBM-MSCs (p < 0.05). In addition, there was a significantly increased total collagen content in the chondrogenically induced hBM-MSCs group (p < 0.01) compared with the native IVDs, cell-free and hIVDC-seeded scaffolds (p < 0.01); both recolonizing cell types were more evenly distributed on the scaffold surface, but only few cells penetrated the scaffold. The resulting decellularized ECM was cytocompatible and allowed hBM-MSCs/hIVDCs survival and ECM production. PMID:27160711

  6. 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

  7. Evaluation of anorganic bovine-derived hydroxyapatite matrix/cell binding peptide as a bone graft material in the treatment of human periodontal infrabony defects: A clinico-radiographic study

    PubMed Central

    Fatima, Ghousia; Shivamurthy, Ravindra; Thakur, Srinath; Baseer, Mohammad Abdul

    2015-01-01

    Background: Various bone graft materials have been used in the treatment of periodontal defects. A synthetic bone substitute material composed of P-15 with anorganic bone mineral has been scantly studied. Hence, the present study was aimed to evaluate and compare the efficacy of anorganic bovine-derived hydroxyapatite matrix (ABM)/cell binding peptide (P-15) in human periodontal infrabony defects with that of open flap debridement (OFD) alone. Materials and Methods: A split-mouth, randomized controlled clinical study was designed to investigate the efficacy of ABM/P-15. In this clinical trial, 10 patients having bilateral periodontal infrabony defects were treated either with ABM/P-15 or OFD and followed for a period of 9 months. At baseline and at 9 months probing pocket depth (PPD), relative attachment level (RAL), depth of a defect, and radiographic bone level were measured; and compared between test and control sites. Results: A statistically significant reduction (P < 0.001) in PPD was observed in test sites compared to control sites. Both sites showed a gain in RAL without any significant difference. Similarly, the radiographic evaluation revealed significantly higher radiographic defect fill in test sites as compared to control sites (P < 0.001). Conclusion: ABM/P-15 bone graft material appears to be useful and beneficial in the treatment of human periodontal infrabony defects. PMID:26941516

  8. 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

  9. Bone marrow mesenchymal stem cells and TGF-β signaling in bone remodeling

    PubMed Central

    Crane, Janet L.; Cao, Xu

    2014-01-01

    During bone resorption, abundant factors previously buried in the bone matrix are released into the bone marrow microenvironment, which results in recruitment and differentiation of bone marrow mesenchymal stem cells (MSCs) for subsequent bone formation, temporally and spatially coupling bone remodeling. Parathyroid hormone (PTH) orchestrates the signaling of many pathways that direct MSC fate. The spatiotemporal release and activation of matrix TGF-β during osteoclast bone resorption recruits MSCs to bone-resorptive sites. Dysregulation of TGF-β alters MSC fate, uncoupling bone remodeling and causing skeletal disorders. Modulation of TGF-β or PTH signaling may reestablish coupled bone remodeling and be a potential therapy. PMID:24487640

  10. Repair of bone defect by using vascular bundle implantation combined with Runx II gene-transfected adipose-derived stem cells and a biodegradable matrix.

    PubMed

    Han, Dong; Li, Jianjun

    2013-06-01

    A large hurdle in orthopedics today is the difficulty of dealing with the non-union of fractured bones. We therefore evaluated the effects of runt-related transcription factor II (Runx II), a factor used to create gene-modified tissue-engineered bone, combined with vascular bundle implantation for repairing segmental bone defects. Adenovirus Runx II gene (Ad-Runx II)-modified rabbit adipose-derived stem cells (ADSCs) were seeded onto polylactic acid/polycaprolacton (PLA/PCL) scaffolds to construct gene-modified tissue-engineered bone. The following four methods were used for repair in rabbit radial-defect (1.5 cm long) models: gene-modified tissue-engineered bone with vascular bundle (Group A), gene-modified tissue-engineered bone (Group B), non-gene-modified tissue-engineered bone with vascular bundle (Group C), and PLA/PCL scaffolds only (Group D). X-ray, histological examination, biomechanics analysis, and micro-angiography were conducted 4, 8, and 12 weeks later to determine angiogenesis and osteogenesis. The volume and speed of production of newly formed bones in Group A were significantly superior to those in other groups, and de-novo vascular network circulation from the vessel bundle through newly formed bone tissue was observed, with the defect being completely repaired. Group B showed a slightly better effect in terms of speed and quality of bone formation than Group C, whereas the bone defect in Group D was replaced by fibrous tissue. The maximal anti-bending strength in Group A was significantly higher than that in the other groups. Runx II gene therapy combined with vascular bundle implantation thus displays excellent abilities for osteoinduction and vascularization and is a promising method for the treatment of bone non-union and defect. PMID:23604755

  11. Aging and Bone

    PubMed Central

    Boskey, A.L.; Coleman, R.

    2010-01-01

    Bones provide mechanical and protective function, while also serving as housing for marrow and a site for regulation of calcium ion homeostasis. The properties of bones do not remain constant with age; rather, they change throughout life, in some cases improving in function, but in others, function deteriorates. Here we review the modifications in the mechanical function and shape of bones, the bone cells, the matrix they produce, and the mineral that is deposited on this matrix, while presenting recent theories about the factors leading to these changes. PMID:20924069

  12. 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

  13. Fabrication and in vitro evaluation of a sponge-like bioactive-glass/gelatin composite scaffold for bone tissue engineering.

    PubMed

    Nadeem, Danish; Kiamehr, Mostafa; Yang, Xuebin; Su, Bo

    2013-07-01

    In this work a bioactive composite scaffold, comprised of bioactive-glass and gelatin, is introduced. Through direct foaming a sponge-like composite of a sol-gel derived bioactive-glass (70S30C; 70% SiO2, 30% CaO) and porcine gelatin was developed for use as a biodegradable scaffold for bone tissue engineering. The composite was developed to provide a suitable alternative to synthetic polymer based scaffolds, allowing directed regeneration of bone tissue. The fabricated scaffold was characterised through X-ray microtomography, scanning electron and light microscopy demonstrating a three dimensionally porous and interconnected structure, with an average pore size (170 μm) suitable for successful cell proliferation and tissue ingrowth. Acellular bioactivity was assessed through apatite formation during submersion in simulated body fluid (SBF) whereby the rate and onset of apatite nucleation was found to be comparable to that of bioactive-glass. Modification of dehydrothermal treatment parameters induced varying degrees of crosslinking, allowing the degradation of the composite to be tailored to suit specific applications and establishing its potential for a wide range of applications. Use of genipin to supplement crosslinking by dehydrothermal treatment provided further means of modifying degradability. Biocompatibility of the composite was qualified through successful cultures of human dental pulp stem cells (HDPSCs) on samples of the composite scaffold. Osteogenic differentiation of HDPSCs and extracellular matrix deposition were confirmed through positive alkaline phosphatase staining and immunohistochemistry. PMID:23623083

  14. Retention of the stemness of mouse adipose-derived stem cells by their expansion on human bone marrow stromal cell-derived extracellular matrix.

    PubMed

    Xiong, Yao; He, Jing; Zhang, Wenjie; Zhou, Guangdong; Cao, Yilin; Liu, Wei

    2015-06-01

    Mesenchymal stem cells (MSCs) usually lose their stemness during in vitro expansion as they are deprived of their niche environment. Cell-extracellular matrix (ECM) interaction is known to play important roles in preserving the stemness of the cells in their stem cell niche environment. Previously, coating with bone marrow MSC (BMSC)-derived ECM was found able to maintain the differentiation potential of in vitro cultured MSCs. This study aimed to determine if this ECM coating could also maintain the stemness of cultured murine adipose-derived stem cells (ASCs) using a regular culture flask as a control. Cells were expanded in ECM-coated and ECM-noncoated flasks for two and four passages and then harvested for various analyses. The results showed that ASCs exhibited fibroblast-like spindle morphology in ECM-coated flasks, whereas ASCs gradually spread and enlarged in the ECM-noncoated flasks. After three and five passages, both groups of cells exhibited similar cytokinetics in the MSC culture medium (MesenPRO RS™ Medium). However, when cultured in Dulbecco's modified Eagles medium (DMEM) plus 10% fetal bovine serum, coating group cells exhibited more potent proliferation than control group cells with a significant difference in both passages 3 and 5 (p<0.01). When seeded at low density (500 cells/10-cm dish), coating group cells formed significantly more and larger sized cell colonies than control group cells with significant difference in cell colony numbers between two groups (p<0.05). In addition, coated colony cells were much smaller and more compactly arranged compared to control colony cells. Furthermore, ASCs expanded in coated flasks exhibited greater potentials for adipogenic, osteogenic, and chondrogenic differentiations than the cells expanded in regular flasks. Quantitatively, the Oil Red O staining area, Alizarin staining area, and Toluidine Blue staining area were all significantly larger than the respective staining areas of control cells (p<0

  15. Mesenchymal stem cells from umbilical cord matrix, adipose tissue and bone marrow exhibit different capability to suppress peripheral blood B, natural killer and T cells

    PubMed Central

    2013-01-01

    Introduction The ability to self-renew, be easily expanded in vitro and differentiate into different mesenchymal tissues, render mesenchymal stem cells (MSCs) an attractive therapeutic method for degenerative diseases. The subsequent discovery of their immunosuppressive ability encouraged clinical trials in graft-versus-host disease and auto-immune diseases. Despite sharing several immunophenotypic characteristics and functional capabilities, the differences between MSCs arising from different tissues are still unclear and the published data are conflicting. Methods Here, we evaluate the influence of human MSCs derived from umbilical cord matrix (UCM), bone marrow (BM) and adipose tissue (AT), co-cultured with phytohemagglutinin (PHA)-stimulated peripheral blood mononuclear cells (MNC), on T, B and natural killer (NK) cell activation; T and B cells’ ability to acquire lymphoblast characteristics; mRNA expression of interleukin-2 (IL-2), forkhead box P3 (FoxP3), T-bet and GATA binding protein 3 (GATA3), on purified T cells, and tumor necrosis factor-alpha (TNF-α), perforin and granzyme B on purified NK cells. Results MSCs derived from all three tissues were able to prevent CD4+ and CD8+ T cell activation and acquisition of lymphoblast characteristics and CD56dim NK cell activation, wherein AT-MSCs showed a stronger inhibitory effect. Moreover, AT-MSCs blocked the T cell activation process in an earlier phase than BM- or UCM-MSCs, yielding a greater proportion of T cells in the non-activated state. Concerning B cells and CD56bright NK cells, UCM-MSCs did not influence either their activation kinetics or PHA-induced lymphoblast characteristics, conversely to BM- and AT-MSCs which displayed an inhibitory effect. Besides, when co-cultured with PHA-stimulated MNC, MSCs seem to promote Treg and Th1 polarization, estimated by the increased expression of FoxP3 and T-bet mRNA within purified activated T cells, and to reduce TNF-α and perforin production by activated NK

  16. The Expression of Bone Morphogenetic Protein 2 and Matrix Metalloproteinase 2 through Retinoic Acid Receptor Beta Induced by All-Trans Retinoic Acid in Cultured ARPE-19 Cells

    PubMed Central

    Gao, Zhenya; Huo, Lijun; Cui, Dongmei; Yang, Xiao; Zeng, Junwen

    2016-01-01

    Purpose All-trans retinoic acid (ATRA) plays an important role in ocular development. Previous studies found that retinoic acid could influence the metabolism of scleral remodeling by promoting retinal pigment epithelium (RPE) cells to secrete secondary signaling factors. The purpose of this study was to investigate whether retinoic acid affected secretion of bone morphogenetic protein 2 (BMP-2) and matrix metalloproteinase 2 (MMP-2) and to explore the signaling pathway of retinoic acid in cultured acute retinal pigment epithelial 19 (ARPE-19) cells. Methods The effects of ATRA (concentrations from 10−9 to 10−5 mol/l) on the expression of retinoic acid receptors (RARs) in ARPE-19 cells were examined at the mRNA and protein levels using reverse transcription-polymerase chain reaction (RT-PCR) and western blot assay, respectively. The effects of treating ARPE-19 cells with ATRA concentrations ranging from 10−9 to 10−5 mol/l for 24 h and 48 h or with 10-6mol/l ATRA at different times ranging from 6h to 72h were assessed using real-time quantitative PCR (qPCR) and enzyme-linked immunosorbent assay (ELISA). The contribution of RARβ-induced activation of ARPE-19 cells was confirmed using LE135, an antagonist of RARβ. Results RARβ mRNA levels significantly increased in the ARPE-19 cells treated with ATRA for 24h and 48h. These increases in RARβ mRNA levels were dose dependent (at concentrations of 10−9 to 10−5 mol/l) with a maximum effect observed at 10−6 mol/l. There were no significant changes in the mRNA levels of RARα and RARγ. Western blot assay revealed that RARβ protein levels were increased significantly in a time-dependent manner in ARPE-19 cells treated with 10−6 mol/l ATRA from 12 h to 72 h, with a marked increase observed at 24 h and 48 h. The upregulation of RARβ and the ATRA-induced secretion in ARPE-19 cells could be inhibited by the RARβ antagonist LE135. Conclusion ATRA induced upregulation of RARβ in ARPE-19 cells and stimulated

  17. Plasma-functionalized electrospun matrix for biograft development and cardiac function stabilization.

    PubMed

    Guex, A G; Frobert, A; Valentin, J; Fortunato, G; Hegemann, D; Cook, S; Carrel, T P; Tevaearai, H T; Giraud, M N

    2014-07-01

    Cardiac tissue engineering approaches can deliver large numbers of cells to the damaged myocardium and have thus increasingly been considered as a possible curative treatment to counteract the high prevalence of progressive heart failure after myocardial infarction (MI). Optimal scaffold architecture and mechanical and chemical properties, as well as immune- and bio-compatibility, need to be addressed. We demonstrated that radio-frequency plasma surface functionalized electrospun poly(ɛ-caprolactone) (PCL) fibres provide a suitable matrix for bone-marrow-derived mesenchymal stem cell (MSC) cardiac implantation. Using a rat model of chronic MI, we showed that MSC-seeded plasma-coated PCL grafts stabilized cardiac function and attenuated dilatation. Significant relative decreases of 13% of the ejection fraction (EF) and 15% of the fractional shortening (FS) were observed in sham treated animals; respective decreases of 20% and 25% were measured 4 weeks after acellular patch implantation, whereas a steadied function was observed 4 weeks after MSC-patch implantation (relative decreases of 6% for both EF and FS). PMID:24531014

  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. Osteopontin Deficiency Increases Bone Fragility but Preserves Bone Mass

    PubMed Central

    Thurner, Philipp J.; Chen, Carol G.; Ionova-Martin, Sophi; Sun, Luling; Harman, Adam; Porter, Alexandra; Ager, Joel W.; Ritchie, Robert O.; Alliston, Tamara

    2010-01-01

    The ability of bone to resist catastrophic failure is critically dependent upon the material properties of bone matrix, a composite of hydroxyapatite, collagen type I, and noncollagenous proteins. These properties include elastic modulus, hardness, and fracture toughness. Like other aspects of bone quality, matrix material properties are biologically-defined and can be disrupted in skeletal disease. While mineral and collagen have been investigated in greater detail, the contribution of noncollagenous proteins such as osteopontin to bone matrix material properties remains unclear. Several roles have been ascribed to osteopontin in bone, many of which have the potential to impact material properties. To elucidate the role of osteopontin in bone quality, we evaluated the structure, composition, and material properties of bone from osteopontin-deficient mice and wild-type littermates at several length scales. Most importantly, the results show that osteopontin deficiency causes a 30% decrease in fracture toughness, suggesting an important role for OPN in preventing crack propagation. This significant decline in fracture toughness is independent of changes in whole bone mass, structure, or matrix porosity. Using nanoindentation and quantitative backscattered electron imaging to evaluate osteopontin-deficient bone matrix at the micrometer level, we observed a significant reduction in elastic modulus and increased variability in calcium concentration. Matrix heterogeneity was also apparent at the ultrastructural level. In conclusion, we find that osteopontin is essential for the fracture toughness of bone, and reduced toughness in osteopontin-deficient bone may be related to the increased matrix heterogeneity observed at the micro-scale. By exploring the effects of osteopontin-deficiency on bone matrix material properties, composition and organization, this study suggests that reduced fracture toughness is one mechanism by which loss of noncollagenous proteins contribute

  20. Histomorphometry and Bone Matrix Mineralization Before and After Bisphosphonate Treatment in Boys With Duchenne Muscular Dystrophy: A Paired Transiliac Biopsy Study.

    PubMed

    Misof, Barbara M; Roschger, Paul; McMillan, Hugh J; Ma, Jinhui; Klaushofer, Klaus; Rauch, Frank; Ward, Leanne M

    2016-05-01

    Duchenne muscular dystrophy (DMD) is a genetic disorder causing progressive muscle weakness. To prolong independent ambulation, DMD patients are treated with glucocorticoids, which, in turn, can increase bone fragility. In a cohort with vertebral fractures, intravenous bisphosphonate (iv BP) therapy stabilized vertebrae and reduced back pain. To characterize the effects of glucocorticoid therapy and bisphosphonate treatment on bone tissue and material properties, paired transiliac biopsy samples (before and after on average 2.4 years of iv BP) from 9 boys with DMD were studied for histomorphometry and bone mineralization density distribution (BMDD) and compared to reference values. Before iv BP, the boys had low cancellous bone volume (BV/TV) and cortical thickness (Ct.Wi) (both on average 56% of the healthy average, p < 0.001 versus reference), and mineralizing surface (MS/BS) in the lower normal range (on average 74% of the healthy average). The average degree of mineralization of cancellous (Cn.CaMean) and cortical compartments (Ct.CaMean) was 21.48 (20.70, 21.90) wt% and 20.42 (19.32, 21.64) wt%, respectively (median [25th, 75th percentiles]), which was not different from reference. After iv BP, BV/TV and Ct.Wi were, on average, unchanged. However, at the individual patient level, BV/TV Z-scores increased in 2, remained unchanged in 4, and declined in 3 patients. Additionally, on average, MS/BS decreased (-85%, p < 0.001), Cn.CaMean (+2.7%) increased, whereas the heterogeneity of cancellous (Cn.CaWidth -19%) and cortical bone mineralization (Ct.CaWidth -8%, all p < 0.05) decreased versus baseline. The changes in bone mineralization are consistent with the antiresorptive action of iv BP. At the same time, our observations point to the need for novel therapies with less or absent bone turnover suppression, including the fact that bone turnover was low even before bisphosphonate therapy, that bone turnover declined further (as expected) with treatment

  1. Bone Grafts

    MedlinePlus

    A bone graft transplants bone tissue. Surgeons use bone grafts to repair and rebuild diseased bones in your hips, knees, spine, and sometimes other bones and joints. Grafts can also repair bone loss caused by some ...

  2. Bone tumor

    MedlinePlus

    Tumor - bone; Bone cancer; Primary bone tumor; Secondary bone tumor ... The cause of bone tumors is unknown. They often occur in areas of the bone that grow rapidly. Possible causes include: Genetic defects ...

  3. 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. PMID:10566613

  4. 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

  5. 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

  6. Bone strength: current concepts.

    PubMed

    Turner, Charles H

    2006-04-01

    Bones serve several mechanical functions, including acoustic amplification in the middle ear, shielding vital organs from trauma, and serving as levers for muscles to contract against. Bone is a multiphase material made up of a tough collagenous matrix intermingled with rigid mineral crystals. The mineral gives bone its stiffness. Without sufficient mineralization, bones will plastically deform under load. Collagen provides toughness to bone making it less brittle so that it better resists fracture. Bone adapts to mechanical stresses largely by changing its size and shape, which are major determinants of its resistance to fracture. Tissue is added in regions of high mechanical stress providing an efficient means for improving bone strength. Experiments have shown that small additions of bone mineral density (BMD) (5-8%) caused by mechanical loading can improve bone strength by over 60% and extend bone fatigue life by 100-fold. Consequently, it is clear that bone tissue possesses a mechanosensing apparatus that directs osteogenesis to where it is most needed for improving bone strength. The biological processes involved in bone mechanotransduction are poorly understood and further investigation of the molecular mechanisms involved might uncover drug targets for osteoporosis. Several pathways are emerging from current research, including membrane ion channels, ATP signaling, second messengers, such as prostaglandins and nitric oxide, insulin-like growth factors, and Wnt signaling. PMID:16831941

  7. Inhibited Wnt Signaling Causes Age-Dependent Abnormalities in the Bone Matrix Mineralization in the Apert Syndrome FGFR2S252W/+ Mice

    PubMed Central

    Zhang, Li; Chen, Peng; Chen, Lin; Weng, Tujun; Zhang, Shichang; Zhou, Xia; Zhang, Bo; Liu, Luchuan

    2015-01-01

    Apert syndrome (AS) is a type of autosomal dominant disease characterized by premature fusion of the cranial sutures, severe syndactyly, and other abnormalities in internal organs. Approximately 70% of AS cases are caused by a single mutation, S252W, in fibroblast growth factor receptor 2 (FGFR2). Two groups have generated FGFR2 knock-in mice Fgfr2S252W/+ that exhibit features of AS. During the present study of AS using the Fgfr2S252W/+ mouse model, an age-related phenotype of bone homeostasis was discovered. The long bone mass was lower in 2 month old mutant mice than in age-matched controls but higher in 5 month old mutant mice. This unusual phenotype suggested that bone marrow-derived mesenchymal stem cells (BMSCs), which are vital to maintain bone homeostasis, might be involved. BMSCs were isolated from Fgfr2S252W/+ mice and found that S252W mutation could impair osteogenic differentiation BMSCs but enhance mineralization of more mature osteoblasts. A microarray analysis revealed that Wnt pathway inhibitors SRFP1/2/4 were up-regulated in mutant BMSCs. This work provides evidence to show that the Wnt/β-catenin pathway is inhibited in both mutant BMSCs and osteoblasts, and differentiation defects of these cells can be ameliorated by Wnt3a treatment. The present study suggested that the bone abnormalities caused by deregulation of Wnt pathway may underlie the symptoms of AS. PMID:25693202

  8. Acellular Vascular Grafts Generated from Collagen and Elastin Analogues

    PubMed Central

    Kumar, Vivek A.; Caves, Jeffrey M.; Haller, Carolyn A.; Dai, Erbin; Li, Liying; Grainger, Stephanie; Chaikof, Elliot L.

    2013-01-01

    Tissue engineered vascular grafts require long fabrication times, in part, due to the requirement of cells from a variety of cell sources to produce a robust load bearing, extracellular matrix. Herein, we propose a design strategy for the fabrication of tubular conduits comprised of collagen fiber networks and elastin-like protein polymers to mimic native tissue structure and function. Dense fibrillar collagen networks exhibited an ultimate tensile strength (UTS) of 0.71 ± 0.06 MPa, strain to failure of 37.1 ± 2.2%, and Young’s modulus of 2.09 ± 0.42 MPa, comparing favorably to an UTS and a Young’s modulus for native blood vessels of 1.4 – 11.1 MPa and 1.5 ± 0.3 MPa, respectively. Resilience, a measure of recovered energy during unloading of matrices, demonstrated that 58.9 ± 4.4% of the energy was recovered during loading-unloading cycles. Rapid fabrication of multilayer tubular conduits with maintenance of native collagen ultrastructure was achieved with internal diameters ranging between 1 to 4 mm. Compliance and burst pressures exceeded 2.7 ± 0.3%/100 mmHg and 830 ± 131 mmHg, respectively, with a significant reduction in observed platelet adherence as compared to ePTFE (6.8 ± 0.05 × 105 vs. 62 ± 0.05 × 105 platelets/mm2, p < 0.01). Using a rat aortic interposition model, early in vivo responses were evaluated at 2 weeks via Doppler ultrasound and CT angiography with immunohistochemistry confirming a limited early inflammatory response (n=8). Engineered collagen-elastin composites represent a promising strategy for fabricating synthetic tissues with defined extracellular matrix content, composition, and architecture. PMID:23743129

  9. Evaluating acellular versus cellular perfusate composition during prolonged ex vivo lung perfusion after initial cold ischaemia for 24 hours.

    PubMed

    Becker, Simon; Steinmeyer, Jasmin; Avsar, Murat; Höffler, Klaus; Salman, Jawad; Haverich, Axel; Warnecke, Gregor; Ochs, Matthias; Schnapper, Anke

    2016-01-01

    Normothermic ex vivo lung perfusion (EVLP) has developed as a powerful technique to evaluate particularly marginal donor lungs prior to transplantation. In this study, acellular and cellular perfusate compositions were compared in an identical experimental setting as no consensus has been reached on a preferred technique yet. Porcine lungs underwent EVLP for 12 h on the basis of an acellular or a cellular perfusate composition after 24 h of cold ischaemia as defined organ stress. During perfusion, haemodynamic and respiratory parameters were monitored. After EVLP, the lung condition was assessed by light and transmission electron microscopy. Aerodynamic parameters did not show significant differences between groups and remained within the in vivo range during EVLP. Mean oxygenation indices were 491 ± 39 in the acellular group and 513 ± 53 in the cellular group. Groups only differed significantly in terms of higher pulmonary artery pressure and vascular resistance in the cellular group. Lung histology and ultrastructure were largely well preserved after prolonged EVLP and showed only minor structural alterations which were similarly present in both groups. Prolonged acellular and cellular EVLP for 12 h are both feasible with lungs prechallenged by ischaemic organ stress. Physiological and ultrastructural analysis showed no superiority of either acellular or cellular perfusate composition. PMID:26264867

  10. Bladder Tissue Regeneration Using Acellular Bi-Layer Silk Scaffolds in a Large Animal Model of Augmentation Cystoplasty

    PubMed Central

    Tu, Duong D.; Chung, Yeun Goo; Gil, Eun Seok; Seth, Abhishek; Franck, Debra; Cristofaro, Vivian; Sullivan, Maryrose P.; Di Vizio, Dolores; Gomez, Pablo; Adam, Rosalyn M.; Kaplan, David L.; Estrada, Carlos R.; Mauney, Joshua R.

    2013-01-01

    A cellular scaffolds derived from Bombyx mori silk fibroin were investigated for their ability to support functional tissue regeneration in a porcine model of augmentation cystoplasty. Two bi-layer matrix configurations were fabricated by solvent-casting/salt leaching either alone (Group 1) or in combination with silk film casting (Group 2) to yield porous foams buttressed by heterogeneous surface pore occlusions or homogenous silk films, respectively. Bladder augmentation was performed with each scaffold group (6×6cm2) in juvenile Yorkshire swine for 3 m of implantation. Augmented animals exhibited high rates of survival (Group 1: 5/6, 83%; Group 2: 4/4, 100%) and voluntary voiding over the course of the study period. Urodynamic evaluations demonstrated mean increases in bladder capacity over pre-operative levels (Group 1: 277%; Group 2: 153%) which exceeded non surgical control gains (144%) encountered due to animal growth. Similarly, elevations in bladder compliance were substantially higher in augmented animals from baseline (Group 1: 357%; Group 2: 147%) in comparison to controls (41%). Gross tissue evaluations revealed that both matrix configurations supported extensive de novo tissue formation throughout the entire original implantation site which exhibited ultimate tensile strength similar to nonsurgical counterparts. Histological and immunohistochemical analyses showed that both implant groups promoted comparable extents of smooth muscle regeneration and contractile protein (α-smooth muscle actin and SM22α) expression within defect sites similar to controls. Parallel evaluations demonstrated the formation of a transitional, multi-layered urothelium with prominent cytokeratin, uroplakin, and p63 protein expression in both matrix groups. De novo innervation and vascularization processes were evident in all regenerated tissues indicated by synaptophysin-positive neuronal cells and vessels lined with CD31 expressing endothelial cells. Ex vivo organ bath

  11. In Vivo Bone Regeneration Using Tubular Perfusion System Bioreactor Cultured Nanofibrous Scaffolds

    PubMed Central

    Yeatts, Andrew B.; Both, Sanne K.; Yang, Wanxun; Alghamdi, Hamdan S.; Yang, Fang; 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(ɛ-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 mm2 at 21 days compared to 0.99±0.43 mm2 and 0.50±0.29 mm2 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 mm2. Defects implanted with statically cultured and acellular scaffolds had a new bone area of 1.26±0.43 mm2 and 1.19±0.33 mm2, 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. PMID:23865551

  12. Free vascularised fibular grafting with OsteoSet®2 demineralised bone matrix versus autograft for large osteonecrotic lesions of the femoral head.

    PubMed

    Feng, Yong; Wang, Shanzhi; Jin, Dongxu; Sheng, Jiagen; Chen, Shengbao; Cheng, Xiangguo; Zhang, Changqing

    2011-04-01

    The aim of this study was to compare the safety and efficacy of OsteoSet®2 DBM with autologous cancellous bone in free vascularised fibular grafting for the treatment of large osteonecrotic lesions of the femoral head. Twenty-four patients (30 hips) with large osteonecrotic lesions of the femoral head (stage IIC in six hips, stage IIIC in 14, and stage IVC in ten, according to the classification system of Steinberg et al.) underwent free vascularised fibular grafting with OsteoSet®2 DBM. This group was retrospectively matched to a group of 24 patients (30 hips) who underwent free vascularised fibular grafting with autologous cancellous bone during the same time period according to the aetiology, stage, and size of the lesion and the mean preoperative Harris hip score. A prospective case-controlled study was then performed with a mean follow-up duration of 26 months. The results show no statistically significant differences between the two groups in overall clinical outcome or the radiographic assessment. Furthermore, no adverse events related to the use of the OsteoSet®2 DBM were observed. The results demonstrate that OsteoSet®2 DBM combined with autograft bone performs equally as well as that of autologous bone alone. Therefore, OsteoSet®2 DBM can be used as a safe and effective graft extender in free vascularised fibular grafting for large osteonecrotic lesions of the femoral head. PMID:20012040

  13. 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 ...

  14. 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.

  15. 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. PMID:27272104

  16. 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

  17. A RANDOMIZED PHASE II TRIAL OF THE MATRIX METALLOPROTEINASE INHIBITOR BMS-275291 IN HORMONE-REFRACTORY PROSTATE CANCER PATIENTS WITH BONE METASTASES

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Background: BMS-275291 is a selective matrix metalloproteinase inhibitor (MMPI) that does not inhibit sheddases implicated in the dose-limiting arthritis of older MMPIs. We conducted a randomized phase II trail of two doses of BMS-275291 (1,200 versus 2,400 mg) in hormone-refractory prostate cancer ...

  18. Biomaterials and bone mechanotransduction

    NASA Technical Reports Server (NTRS)

    Sikavitsas, V. I.; Temenoff, J. S.; Mikos, A. G.; McIntire, L. V. (Principal Investigator)

    2001-01-01

    Bone is an extremely complex tissue that provides many essential functions in the body. Bone tissue engineering holds great promise in providing strategies that will result in complete regeneration of bone and restoration of its function. Currently, such strategies include the transplantation of highly porous scaffolds seeded with cells. Prior to transplantation the seeded cells are cultured in vitro in order for the cells to proliferate, differentiate and generate extracellular matrix. Factors that can affect cellular function include the cell-biomaterial interaction, as well as the biochemical and the mechanical environment. To optimize culture conditions, good understanding of these parameters is necessary. The new developments in bone biology, bone cell mechanotransduction, and cell-surface interactions are reviewed here to demonstrate that bone mechanotransduction is strongly influenced by the biomaterial properties.

  19. Screening for Oxidative Stress Elicited by Engineered Nanomaterials: Evaluation of Acellular DCFH Assay

    PubMed Central

    Pal, Anoop K.; Bello, Dhimiter; Budhlall, Bridgette; Rogers, Eugene; Milton, Donald K.

    2012-01-01

    The DCFH assay is commonly used for measuring free radicals generated by engineered nanomaterials (ENM), a well-established mechanism of ENM toxicity. Concerns exist over susceptibility of the DCFH assay to: assay conditions, adsorption of DCFH onto ENM, fluorescence quenching and light scattering. These effects vary in magnitude depending on ENM physiochemical properties and concentration. A rigorous evaluation of this method is still lacking. The objective was to evaluate performance of the DCFH assay for measuring ENM-induced free radicals. A series of diverse and well-characterized ENM were tested in the acellular DCFH assay. We investigated the effect of sonication conditions, dispersion media, ENM concentration, and the use of horseradish peroxidase (HRP) on the DCFH results. The acellular DCFH assay suffers from high background signals resulting from dye auto-oxidation and lacks sensitivity and robustness. DCFH oxidation is further enhanced by HRP. The number of positive ENM in the assay and their relative ranking changed as a function of experimental conditions. An inverse dose relationship was observed for several Carbon-based ENM. Overall, these findings indicate the importance of having standardized assays for evaluating ENM toxicity and highlights limitations of the DCFH assay for measuring ENM-induced free radicals. PMID:22942866

  20. Alternatives to HIST for acellular pertussis vaccines: progress and challenges in replacement

    PubMed Central

    Arciniega, J.; Wagner, L.; Prymula, R.; Sebo, P.; Isbrucker, R.; Descampe, B.; Chapsal, J.M.; Costanzo, A.; Hendriksen, C.; Hoonaker, M.; Nelson, S.; Lidster, K.; Casey, W.; Allen, D.

    2016-01-01

    The ‘International Workshop on Alternatives to the Murine Histamine Sensitization Test for Acellular Pertussis Vaccines: Progress and Challenges in the Replacement of HIST’ was held on 24 August 2014, in Prague, Czech Republic, as a satellite meeting to the 9 th World Congress on Alternatives and Animal Use in the Life Sciences. Participants discussed the progress and challenges associated with the development, validation, and implementation of in vitro assays as replacements for the histamine sensitisation test (HIST) for acellular pertussis vaccines. Discussions focused on the consistency approach, the necessary framework for regulatory acceptance of a harmonised method, and recent international efforts towards the development of in vitro assays to replace the HIST. Workshop participants agreed that acceptable alternatives to the HIST should be based on ADP ribosylation-mediated cell intoxication and therefore that the CHO cell clustering assay, which measures cell intoxication, should be further pursued and developed as a possible replacement for the HIST. Participants also agreed to continue ongoing multinational discussions involving national and international standardisation authorities to reach consensus and to organise collaborative studies in this context for assay characterisation and calibration of reference materials. PMID:27506225

  1. Multiplex immunoassay for in vitro characterization of acellular pertussis antigens in combination vaccines.

    PubMed

    Agnolon, Valentina; Bruno, Cristina; Galletti, Bruno; Mori, Elena; Ugozzoli, Mildred; Pergola, Carlo; O'Hagan, Derek T; Baudner, Barbara C

    2016-02-17

    Vaccines characterization is required to ensure physical, chemical, and biological integrity of antigens and adjuvants. Current analytical methods mostly require complete antigen desorption from aluminum-based adjuvants and are not always suitable to distinguish individual antigens in multivalent formulations. Here, Luminex technology is proposed to improve the analytics of vaccine characterization. As proof of concept, TdaP (tetanus, diphtheria and acellular pertussis) combination, adjuvanted with aluminum hydroxide, was chosen as model formulation to quantify and determine the level of adsorption of acellular pertussis (aP) antigens onto adjuvant surface at the same time. The assay used specific antibodies bound to magnetic microspheres presenting unique digital signatures for each pertussis antigen, allowing the simultaneous recognition of respective antigens in the whole vaccine, avoiding laborious procedures for adjuvant separation. Accurate and reproducible quantification of aP antigens in TdaP vaccine has been achieved in the range 0.78-50 ng/mL, providing simultaneously information on antigen identity, quantity, and degree of adsorption to aluminum hydroxide. The current study could further be considered as a model to set up in vitro potency assays thus supporting the replacement of animal tests accordingly to the 3Rs concept. PMID:26784684

  2. A new method using xenogeneicacellular dermal matrix in the reconstruction of lacrimal drainage

    PubMed Central

    Chen, Li; Gong, Bo; Wu, Zhengzheng; Jetton, Jacquelyn; Chen, Rong; Qu, Chao

    2014-01-01

    Aims To prospectively evaluate the reliability and efficacy of a new treatment for the reconstruction of the lacrimal duct using a new histo-engineered material, xenogeneic (bovine) acellular dermal matrix. Method Five patients (five eyes) with partial or total absence of the lacrimal duct were included in the study. Four patients (four eyes) suffered from traumatic injuries to the lacrimal duct and one patient (one eye) had congenital absence of the lacrimal drainage system. A pedal graft of conjunctiva was taken from the fornix area and rolled into a tube structure after being attached to the acellular dermal matrix. Results The average duration of follow-up for the patients was 7.2 months (ranging from 6 to 12 months). After surgery, the new duct in the nasal cavity could be observed above the middle turbinate by nasal endoscopy. Patency was confirmed by pressing in the area of the lacrimal sac and visualising air bubbles in the nasal cavity. Additionally, the meatus above the middle turbinate of the nasal cavity was stained and visualised after patients underwent Jones dye test 1 (JDT1). Five tear ducts proved to be effective through irrigation testing and epiphora symptoms were alleviated in all cases. Conclusions The newly reconstructed lacrimal duct, formed by the shift of autogenous conjunctival petal and the attachment of acellular dermal matrix, was successful in all five cases and suggests a new solution for the complex lacrimal duct lesion and congenital anomalies of the lacrimal duct. PMID:25271909

  3. Multiscale imaging of bone microdamage.

    PubMed

    Poundarik, Atharva A; Vashishth, Deepak

    2015-04-01

    Bone is a structural and hierarchical composite that exhibits remarkable ability to sustain complex mechanical loading and resist fracture. Bone quality encompasses various attributes of bone matrix from the quality of its material components (type-I collagen, mineral and non-collagenous matrix proteins) and cancellous microarchitecture, to the nature and extent of bone microdamage. Microdamage, produced during loading, manifests in multiple forms across the scales of hierarchy in bone and functions to dissipate energy and avert fracture. Microdamage formation is a key determinant of bone quality, and through a range of biological and physical mechanisms, accumulates with age and disease. Accumulated microdamage in bone decreases bone strength and increases bone's propensity to fracture. Thus, a thorough assessment of microdamage, across the hierarchical levels of bone, is crucial to better understand bone quality and bone fracture. This review article details multiple imaging modalities that have been used to study and characterize microdamage; from bulk staining techniques originally developed by Harold Frost to assess linear microcracks, to atomic force microscopy, a modality that revealed mechanistic insights into the formation diffuse damage at the ultrastructural level in bone. New automated techniques using imaging modalities, such as microcomputed tomography are also presented for a comprehensive overview. PMID:25664772

  4. Increased Expression of Matrix Extracellular Phosphoglycoprotein (MEPE) in Cortical Bone of the Rat Tibia after Mechanical Loading: Identification by Oligonucleotide Microarray

    PubMed Central

    Reijnders, Christianne M. A.; van Essen, Huib W.; van Rens, Birgitte T. T. M.; van Beek, Johannes H. G. M.; Ylstra, Bauke; Blankenstein, Marinus A.; Lips, Paul; Bravenboer, Nathalie

    2013-01-01

    Skeletal integrity in humans and animals is maintained by daily mechanical loading. It has been widely accepted that osteocytes function as mechanosensors. Many biochemical signaling molecules are involved in the response of osteocytes to mechanical stimulation. The aim of this study was to identify genes involved in the translation of mechanical stimuli into bone formation. The four-point bending model was used to induce a single period of mechanical loading on the right tibia, while the contra lateral left tibia served as control. Six hours after loading, the effects of mechanical loading on gene-expression were determined with microarray analysis. Protein expression of differentially regulated genes was evaluated with immunohistochemistry. Nine genes were found to exhibit a significant differential gene expression in LOAD compared to control. MEPE, Garnl1, V2R2B, and QFG-TN1 olfactory receptor were up-regulated, and creatine kinase (muscle form), fibrinogen-B beta-polypeptide, monoamine oxidase A, troponin-C and kinesin light chain-C were down-regulated. Validation with real-time RT-PCR analysis confirmed the up-regulation of MEPE and the down-regulation of creatine kinase (muscle form) and troponin-C in the loaded tibia. Immunohistochemistry showed that the increase of MEPE protein expression was already detectable six hours after mechanical loading. In conclusion, these genes probably play a role during translation of mechanical stimuli six hours after mechanical loading. The modulation of MEPE expression may indicate a connection between bone mineralization and bone formation after mechanical stimulation. PMID:24255709

  5. Link Protein N-terminal Peptide Binds to Bone Morphogenetic Protein (BMP) Type II Receptor and Drives Matrix Protein Expression in Rabbit Intervertebral Disc Cells*

    PubMed Central

    Wang, Zili; Weitzmann, M. Neale; Sangadala, Sreedhara; Hutton, William C.; Yoon, S. Tim

    2013-01-01

    Intervertebral disc (IVD) degeneration and associated spinal disorders are leading sources of morbidity, and they can be responsible for chronic low back pain. Treatments for degenerative disc diseases continue to be a challenge. Intensive research is now focusing on promoting regeneration of degenerated discs by stimulating production of the disc matrix. Link protein N-terminal peptide (LPP) is a proteolytic fragment of link protein, an important cross-linker and stabilizer of the major structural components of cartilage, aggrecan and hyaluronan. In this study we investigated LPP action in rabbit primary intervertebral disc cells cultured ex vivo in a three-dimensional alginate matrix. Our data reveal that LPP promotes disc matrix production, which was evidenced by increased expression of the chondrocyte-specific transcription factor SOX9 and the extracellular matrix macromolecules aggrecan and collagen II. Using colocalization and pulldown studies we further document a noggin-insensitive direct peptide-protein association between LPP and BMP-RII. This association mediated Smad signaling that converges on BMP genes leading to expression of BMP-4 and BMP-7. Furthermore, through a cell-autonomous loop BMP-4 and BMP-7 intensified Smad1/5 signaling though a feedforward circuit involving BMP-RI, ultimately promoting expression of SOX9 and downstream aggrecan and collagen II genes. Our data define a complex regulatory signaling cascade initiated by LPP and suggest that LPP may be a useful therapeutic substitute for direct BMP administration to treat IVD degeneration and to ameliorate IVD-associated chronic low back pain. PMID:23940040

  6. Bone Diseases

    MedlinePlus

    ... also avoid smoking and drinking too much alcohol. Bone diseases can make bones easy to break. Different kinds ... Bones can also develop cancer and infections Other bone diseases, which are caused by poor nutrition, genetics, or ...

  7. Bone Grafts

    MedlinePlus

    ... repair and rebuild diseased bones in your hips, knees, spine, and sometimes other bones and joints. Grafts can also repair bone loss caused by some types of fractures or cancers. Once your body accepts the bone ...

  8. Multiscale imaging of bone microdamage

    PubMed Central

    Poundarik, Atharva A.; Vashishth, Deepak

    2015-01-01

    Bone is a structural and hierarchical composite that exhibits remarkable ability to sustain complex mechanical loading and resist fracture. Bone quality encompasses various attributes of bone matrix from the quality of its material components (type-I collagen, mineral and non-collagenous matrix proteins) and cancellous microarchitecture, to the nature and extent of bone microdamage. Microdamage, produced during loading, manifests in multiple forms across the scales of hierarchy in bone and functions to dissipate energy and avert fracture. Microdamage formation is a key determinant of bone quality, and through a range of biological and physical mechanisms, accumulates with age and disease. Accumulated microdamage in bone decreases bone strength and increases bone’s propensity to fracture. Thus, a thorough assessment of microdamage, across the hierarchical levels of bone, is crucial to better understand bone quality and bone fracture. This review article details multiple imaging modalities that have been used to study and characterize microdamage; from bulk staining techniques originally developed by Harold Frost to assess linear microcracks, to atomic force microscopy, a modality that revealed mechanistic insights into the formation diffuse damage at the ultrastructural level in bone. New automated techniques using imaging modalities such as microcomputed tomography are also presented for a comprehensive overview. PMID:25664772

  9. [Many issues about bone quality].

    PubMed

    Saito, Mitsuru

    2012-06-01

    According to the present definition of osteoporosis, bone mineral density, architecture, and tissue material properties are important factors in determining bone strength. Bone matrix consists of a two-phase composite material in which the mineral phase provides stiffness and collagen provide tensile strength and ductility. The proposed determinants of bone strength at the material level are the degree of mineralization of basic structure units, microdamage accumulation, and collagen cross-link formation. These are regulated by cellular activities, tissue turnover rate, and the levels of oxidative stress and glycation. In this review, I describe the concerns regarding bone qualities. PMID:22653026

  10. Acellular Bi-Layer Silk Fibroin Scaffolds Support Tissue Regeneration in a Rabbit Model of Onlay Urethroplasty

    PubMed Central

    Franck, Debra; Gil, Eun Seok; Algarrahi, Khalid; Adam, Rosalyn M.; Kaplan, David L.; Estrada Jr., Carlos R.; Mauney, Joshua R.

    2014-01-01

    Acellular scaffolds derived from Bombyx mori silk fibroin were investigated for their ability to support functional tissue regeneration in a rabbit model of urethra repair. A bi-layer silk fibroin matrix was fabricated by a solvent-casting/salt leaching process in combination with silk fibroin film casting to generate porous foams buttressed by homogeneous silk fibroin films. Ventral onlay urethroplasty was performed with silk fibroin grafts (Group 1, N = 4) (Width×Length, 1×2 cm2) in adult male rabbits for 3 m of implantation. Parallel control groups consisted of animals receiving small intestinal submucosa (SIS) implants (Group 2, N = 4) or urethrotomy alone (Group 3, N = 3). Animals in all groups exhibited 100% survival prior to scheduled euthanasia and achieved voluntary voiding following 7 d of initial catheterization. Retrograde urethrography of each implant group at 3 m post-op revealed wide urethral calibers and preservation of organ continuity similar to pre-operative and urethrotomy controls with no evidence of contrast extravasation, strictures, fistulas, or stone formation. Histological (hematoxylin and eosin and Masson's trichrome), immunohistochemical, and histomorphometric analyses demonstrated that both silk fibroin and SIS scaffolds promoted similar extents of smooth muscle and epithelial tissue regeneration throughout the original defect sites with prominent contractile protein (α-smooth muscle actin and SM22α) and cytokeratin expression, respectively. De novo innervation and vascularization were also evident in all regenerated tissues indicated by synaptophysin-positive neuronal cells and vessels lined with CD31 expressing endothelial cells. Following 3 m post-op, minimal acute inflammatory reactions were elicited by silk fibroin scaffolds characterized by the presence of eosinophil granulocytes while SIS matrices promoted chronic inflammatory responses indicated by mobilization of mononuclear cell infiltrates. The results of this

  11. Tissue-engineered acellular small diameter long-bypass grafts with neointima-inducing activity.

    PubMed

    Mahara, Atsushi; Somekawa, Shota; Kobayashi, Naoki; Hirano, Yoshiaki; Kimura, Yoshiharu; Fujisato, Toshiya; Yamaoka, Tetsuji

    2015-07-01

    Researchers have attempted to develop efficient antithrombogenic surfaces, and yet small-caliber artificial vascular grafts are still unavailable. Here, we demonstrate the excellent patency of tissue-engineered small-caliber long-bypass grafts measuring 20-30 cm in length and having a 2-mm inner diameter. The inner surface of an acellular ostrich carotid artery was modified with a novel heterobifunctional peptide composed of a collagen-binding region and the integrin α4β1 ligand, REDV. Six grafts were transplanted in the femoral-femoral artery crossover bypass method. Animals were observed for 20 days and received no anticoagulant medication. No thrombogenesis was observed on the luminal surface and five cases were patent. In contrast, all unmodified grafts became occluded, and severe thrombosis was observed. The vascular grafts reported here are the first successful demonstrations of short-term patency at clinically applicable sizes. PMID:25941782

  12. Gravity related behavior of the acellular slime mold Physarum polycephalum (7-IML-1)

    NASA Technical Reports Server (NTRS)

    Block, I.

    1992-01-01

    The objective of the experiment is to investigate the effect of near weightlessness on a single cell. The test object is the acellular slime mold Physarum polycephalum. This cell is composed of a network of protoplastic strands which perform rhythmic contractions in the minute range. These contractions of the strands' ectoplastic walls generate the force to drive the vigorous shuttle streaming of fluid protoplasm inside the strands (hydrostatic pressure flow). A net transport of protoplasm in one direction determines the direction of the cell's locomotion itself. In this way, gravity modifies the contraction rhythm of the strands, the streaming velocity of protoplasm in the strands, and the direction of locomotion of the whole slime mold (geotaxis). The other parts of this experiment will address the major question of how this cell, which does not possess any specialized gravireceptors, gets the information about the direction of the gravity vector. Details of the experimental setup are given.

  13. Physiological distal drift in rat molars contributes to acellular cementum formation.

    PubMed

    Tsuchiya, Shinobu; Tsuchiya, Masahiro; Nishioka, Takashi; Suzuki, Osamu; Sasano, Yasuyuki; Igarashi, Kaoru

    2013-08-01

    Occlusal forces may induce the physiological teeth migration in humans, but there is little direct evidence. Rat molars are known to migrate distally during aging, possibly caused by occlusal forces. The purpose of this study was to determine if a reduction in occlusion would decrease teeth migration and affect associated periodontal structures such as cementum. To reduce occlusal forces, the right upper first molar (M1) in juvenile rats was extracted. The transition of the position of upper second molar (M2) and formation of M2 cementum was followed during aging. From the cephalometric analyses, upper M2 was located more anterior compared with the original position with aging after M1 extraction. Associated with this "slowing-down" of the physiological drift, cementum thickness on distal surface, but not on mesial surface, of M2 root was significantly increased. The accumulation of alizarin red as vital stain indicative of calcification, was observed in the distal cementum of M2 root only on the side of M1 extraction. Extraction of M1 that results in less functional loading, distinctly attenuates the physiological drift only in the upper dentition. The decreased physiological drift appears to activate acellular cementum formation only on distal surface of M2 root, perhaps due to reduced mechanical stress associated with the attenuated distal drift. In conclusion, the physiological distal drift in rat molars appears to be largely driven by the occlusal force and also affects the formation of acellular cementum. These findings provide additional direct evidence for an important role of occlusal forces in tooth migration. PMID:23775928

  14. Immobilization of cross linked Col-I-OPN bone matrix protein on aminolysed PCL surfaces enhances initial biocompatibility of human adipogenic mesenchymal stem cells (hADMSC)

    NASA Astrophysics Data System (ADS)

    Kim, Young-Hee; Jyoti, Md. Anirban; Song, Ho-Yeon

    2014-06-01

    In bone tissue engineering surface modification is considered as one of the important ways of fabricating successful biocompatible material. Addition of biologically active functionality on the surfaces has been tried for improving the overall biocompatibility of the system. In this study poly-ɛ-caprolactone film surfaces have been modified through aminolysis and immobilization process. Collagen type I (COL-I) and osteopontin (OPN), which play an important role in osteogenesis, was immobilized onto PCL films followed by aminolysis treatment using 1,6-hexanediamine. Characterization of animolysed and immobilized surfaces were done by a number techniques using scanning electron microscopy (SEM), FT-IR, XPS, ninhydrin staining, SDS-PAGE and confocal microscopy and compared between the modified and un-modified surfaces. Results of the successive experiments showed that aminolysis treatment was homogeneously achieved which helped to entrap or immobilize Col-I-OPN proteins on surfaces of PCL film. In vitro studies with human adipogenic mesenchymal stem cells (hADMSC) also confirmed the attachment and proliferation of cells was better in modified PCL surfaces than the unmodified surfaces. SEM, confocal microscopy and MTT assay showed a significant increase in cell spreading, attachment and proliferations on the biofunctionalized surfaces compared to the unmodified PCL surfaces at all-time points indicating the success of surface biofunctionalization.

  15. Repair of Postoperative Abdominal Hernia in a Child with Congenital Omphalocele Using Porcine Dermal Matrix.

    PubMed

    Lambropoulos, V; Mylona, E; Mouravas, V; Tsakalidis, C; Spyridakis, I; Mitsiakos, G; Karagianni, P

    2016-01-01

    Introduction. Incisional hernias are a common complication appearing after abdominal wall defects reconstruction, with omphalocele and gastroschisis being the most common etiologies in children. Abdominal closure of these defects represents a real challenge for pediatric surgeons with many surgical techniques and various prosthetic materials being used for this purpose. Case Report. We present a case of repair of a postoperative ventral hernia occurring after congenital omphalocele reconstruction in a three-and-a-half-year-old child using an acellular, sterile, porcine dermal mesh. Conclusion. Non-cross-linked acellular porcine dermal matrix is an appropriate mesh used for the reconstruction of abdominal wall defects and their postoperative complications like large ventral hernias with success and preventing their recurrence. PMID:27110247

  16. Repair of Postoperative Abdominal Hernia in a Child with Congenital Omphalocele Using Porcine Dermal Matrix

    PubMed Central

    Mylona, E.; Tsakalidis, C.; Spyridakis, I.; Mitsiakos, G.; Karagianni, P.

    2016-01-01

    Introduction. Incisional hernias are a common complication appearing after abdominal wall defects reconstruction, with omphalocele and gastroschisis being the most common etiologies in children. Abdominal closure of these defects represents a real challenge for pediatric surgeons with many surgical techniques and various prosthetic materials being used for this purpose. Case Report. We present a case of repair of a postoperative ventral hernia occurring after congenital omphalocele reconstruction in a three-and-a-half-year-old child using an acellular, sterile, porcine dermal mesh. Conclusion. Non-cross-linked acellular porcine dermal matrix is an appropriate mesh used for the reconstruction of abdominal wall defects and their postoperative complications like large ventral hernias with success and preventing their recurrence. PMID:27110247

  17. Intervertebral Disc Tissue Engineering with Natural Extracellular Matrix-Derived Biphasic Composite Scaffolds

    PubMed Central

    Xu, Baoshan; Xu, Haiwei; Wu, Yaohong; Li, Xiulan; Zhang, Yang; Ma, Xinlong; Yang, Qiang

    2015-01-01

    Tissue engineering has provided an alternative therapeutic possibility for degenerative disc diseases. However, we lack an ideal scaffold for IVD tissue engineering. The goal of this study is to fabricate a novel biomimetic biphasic scaffold for IVD tissue engineering and evaluate the feasibility of developing tissue-engineered IVD in vitro and in vivo. In present study we developed a novel integrated biphasic IVD scaffold using a simple freeze-drying and cross-linking technique of pig bone matrix gelatin (BMG) for the outer annulus fibrosus (AF) phase and pig acellular cartilage ECM (ACECM) for the inner nucleus pulposus (NP) phase. Histology and SEM results indicated no residual cells remaining in the scaffold that featured an interconnected porous microstructure (pore size of AF and NP phase 401.4±13.1 μm and 231.6±57.2 μm, respectively). PKH26-labeled AF and NP cells were seeded into the scaffold and cultured in vitro. SEM confirmed that seeded cells could anchor onto the scaffold. Live/dead staining showed that live cells (green fluorescence) were distributed in the scaffold, with no dead cells (red fluorescence) being found. The cell—scaffold constructs were implanted subcutaneously into nude mice and cultured for 6 weeks in vivo. IVD-like tissue formed in nude mice as confirmed by histology. Cells in hybrid constructs originated from PKH26-labeled cells, as confirmed by in vivo fluorescence imaging system. In conclusion, the study demonstrates the feasibility of developing a tissue-engineered IVD in vivo with a BMG- and ACECM-derived integrated AF-NP biphasic scaffold. As well, PKH26 fluorescent labeling with in vivo fluorescent imaging can be used to track cells and analyse cell—scaffold constructs in vivo. PMID:25894203

  18. The Roles of Matrix Polymer Crystallinity and Hydroxyapatite Nanoparticles in Modulating Material Properties of Photo-crosslinked Composites and Bone Marrow Stromal Cell Responses

    PubMed Central

    Wang, Shanfeng; Kempen, Diederik H. R.; Yaszemski, Michael J.; Lu, Lichun

    2010-01-01

    Two poly(ε-caprolactone fumarate)s (PCLFs) with distinct physical properties have been employed to prepare nanocomposites with hydroxyapatite (HA) nanoparticles via photo-crosslinking. The two PCLFs are PCLF530 and PCLF2000, named after their precursor PCL diol molecular weight of 530 and 2000 g.mol-1, respectively. Crosslinked PCLF530 is amorphous while crosslinked PCLF2000 is semi-crystalline with a melting temperature (Tm) of ∼40 °C and a crystallinity of 40%. Consequently, the rheological and mechanical properties of crosslinked PCLF2000 are significantly greater than those of crosslinked PCLF530. Structural characterizations and physical properties of both series of crosslinked PCLF/HA nanocomposites with HA compositions of 0%, 5%, 10%, 20%, and 30% have been investigated. By adding HA nanoparticles, crosslinked PCLF530/HA nanocomposites demonstrate enhanced rheological and mechanical properties while the enhancement in compressive modulus is less prominent in crosslinked PCLF2000/HA nanocomposites. In vitro cell attachment and proliferation have been performed using rat bone marrow stromal cells (BMSCs) and correlated with the material properties. Cell attachment and proliferation on crosslinked PCLF530/HA nanocomposite disks have been enhanced strongly with increasing the HA composition. However, surface morphology and surface chemistry such as composition, hydrophilicity, and the capability of adsorbing protein cannot be used to interpret the cell responses on different samples. Instead, the role of surface stiffness in regulating cell responses can be supported by the correlation between the change in compressive modulus and BMSC proliferation on these two series of crosslinked PCLFs and PCLF/HA nanocomposites. PMID:19339048

  19. Analyzing the cellular contribution of bone marrow to fracture healing using bone marrow transplantation in mice

    SciTech Connect

    Colnot, C. . E-mail: colnotc@orthosurg.ucsf.edu; Huang, S.; Helms, J.

    2006-11-24

    The bone marrow is believed to play important roles during fracture healing such as providing progenitor cells for inflammation, matrix remodeling, and cartilage and bone formation. Given the complex nature of bone repair, it remains difficult to distinguish the contributions of various cell types. Here we describe a mouse model based on bone marrow transplantation and genetic labeling to track cells originating from bone marrow during fracture healing. Following lethal irradiation and engraftment of bone marrow expressing the LacZ transgene constitutively, wild type mice underwent tibial fracture. Donor bone marrow-derived cells, which originated from the hematopoietic compartment, did not participate in the chondrogenic and osteogenic lineages during fracture healing. Instead, the donor bone marrow contributed to inflammatory and bone resorbing cells. This model can be exploited in the future to investigate the role of inflammation and matrix remodeling during bone repair, independent from osteogenesis and chondrogenesis.

  20. Bone impairment in oxalosis: An ultrastructural bone analysis.

    PubMed

    Bacchetta, Justine; Farlay, Delphine; Abelin-Genevois, Kariman; Lebourg, Ludivine; Cochat, Pierre; Boivin, Georges

    2015-12-01

    Deposition of calcium oxalate crystals in the kidney and bone is a hallmark of systemic oxalosis. Since the bone compartment can store massive amounts of oxalate, patients present with recurrent low-trauma fractures, bone deformations, severe bone pains and specific oxalate osteopathy on plain X-ray. Bone biopsy from the iliac crest displays specific features such as oxalate crystals surrounded by a granulomatous reaction due to an invasion of bone surface by macrophages. We present data obtained in 10 samples from 8 patients with oxalosis (16-68 years) who underwent iliac crest bone biopsy and bone quality analysis using modern methods (microradiography, microindentation, Fourier Transform InfraRed Microspectroscopy, transmission electron microscopy) in addition to histomorphometry. Disseminated calcium oxalate deposits (whewellite) were found in the bone marrow space (with a granulomatous reaction) but not in the bone matrix. Calcium oxalate deposits were totally surrounded by macrophages and multinucleated giant cells, and a phagocytosis activity was sometimes observed. Very few calcium oxalate crystals were directly in close contact with the mineral substance of the bone. Bone mineralization was not modified by the presence of calcium oxalate even in close vicinity. Bone quality analysis also revealed a harder bone than normal, perhaps in relationship with decreased carbonate content in the mineral. This increase in bone hardness could explain a more "brittle" bone. In patients with oxalosis, the formation and growth of calcium oxalate crystals in the bone appeared independent of apatite. The mechanisms leading to nucleation and growth of oxalate deposits are still unclear and deserve further studies. PMID:26164477

  1. Living Bones, Strong Bones

    NASA Video Gallery

    In this classroom activity, engineering, nutrition, and physical activity collide when students design and build a healthy bone model of a space explorer which is strong enough to withstand increas...

  2. Bone scan

    MedlinePlus

    ... scan is an imaging test used to diagnose bone diseases and find out how severe they are. How ... a 3-phase bone scan. To evaluate metastatic bone disease, images are taken only after the 3- to ...

  3. Bone Cancer

    MedlinePlus

    Cancer that starts in a bone is uncommon. Cancer that has spread to the bone from another ... more common. There are three types of bone cancer: Osteosarcoma - occurs most often between ages 10 and ...

  4. Bone scan

    MedlinePlus

    A bone scan is an imaging test used to diagnose bone diseases and find out how severe they are. ... A bone scan involves injecting a very small amount of radioactive material (radiotracer) into a vein. The substance travels through ...

  5. Bone Density

    MedlinePlus

    ... bone health. It compares your bone density, or mass, to that of a healthy person who is ... Whether your osteoporosis treatment is working Low bone mass that is not low enough to be osteoporosis ...

  6. Bone Tumor

    MedlinePlus

    ... most common types of primary bone cancer are: • Multiple myeloma. Multiple myeloma is the most common primary bone cancer. It ... Any bone can be affected by this cancer. Multiple myeloma affects approximately six people per 100,000 each ...

  7. Bone Cancer

    MedlinePlus

    Cancer that starts in a bone is uncommon. Cancer that has spread to the bone from another part of the body is more common. There are three types of bone cancer: Osteosarcoma - occurs most often between ages 10 ...

  8. Mechanisms balancing skeletal matrix synthesis and degradation.

    PubMed Central

    Blair, Harry C; Zaidi, Mone; Schlesinger, Paul H

    2002-01-01

    Bone is regulated by evolutionarily conserved signals that balance continuous differentiation of bone matrix-producing cells against apoptosis and matrix removal. This is continued from embryogenesis, where the skeleton differentiates as a solid mass and is shaped into separate bones by cell death and proteolysis. The two major tissues of the skeleton are avascular cartilage, with an extracellular matrix based on type II collagen and hydrophilic proteoglycans, and bone, a stronger and lighter material based on oriented type I collagen and hydroxyapatite. Both differentiate from the same mesenchymal stem cells. This differentiation is regulated by a family of related signals centred on bone morphogenic proteins. Fibroblast growth factors, Indian hedgehog and parathyroid hormone-related protein are important in determining the type of matrix and the relation of skeletal and non-skeletal structures. Removal of mineralized matrix involves apoptosis of matrix cells and differentiation of acid-secreting cells (osteoclasts) from macrophage precursors. Key regulators of matrix removal are signals in the tumour-necrosis-factor family. Osteoclasts dissolve bone by isolating a region of the matrix and secreting HCl and proteinases at that site. Successive cycles of removal and replacement allow growth, repair and remodelling. The signals for bone turnover are predominantly cell-membrane-associated, allowing very specific spatial regulation. In addition to its support function, bone is a reservoir of Ca2+, PO3-(4) and OH-. Secondary modulation of mineral secretion and bone degradation are mediated by humoral signals, including parathyroid hormone and vitamin D, as well as the cytokines that also regulate the underlying cell differentiation. PMID:12023876

  9. Deep Anterior Lamellar Keratoplasty Using Irradiated Acellular Cornea with Amniotic Membrane Transplantation for Intractable Ocular Surface Diseases

    PubMed Central

    Wee, Sung Wook; Choi, Sang Uk

    2015-01-01

    Purpose To report the clinical outcomes of deep anterior lamellar keratoplasty (DALK) when sterile gamma-irradiated acellular corneal tissues (VisionGraft) are used in combination with amniotic membrane transplantation (AMT) for intractable ocular surface diseases. Methods The medical records of fifteen patients who had DALK with AMT were retrospectively reviewed. Indications for surgery included ocular burn, bacterial keratitis, herpes simplex virus keratitis, corneal opacity with Stevens-Johnson syndrome, Mooren's ulcer, idiopathic myxoid degeneration of corneal stroma, and recurrent band keratopathy. DALK was performed using partial-thickness acellular corneal tissue and a temporary amniotic membrane patch was added at the end of the operation. Results All cases that underwent DALK with AMT became epithelialized within 2 postoperative weeks. Twelve patients showed favorable outcomes without graft rejection, corneal opacification, or neovascularization. The other three grafts developed corneal opacification and neovascularization, and required additional penetrating keratoplasty (PK). Unlike the results of previous PKs, there were no graft rejections and the graft clarity was well-maintained in these three cases for at least 8 months after PK. Conclusions DALK using sterile acellular corneal tissues in combination with AMT may be a good therapeutic strategy for treating intractable ocular surface diseases because of lowered immune rejection, fibroblast activation, and facilitation of epithelialization. Furthermore, DALK can help stabilize the ocular surface, prolong graft survival, and may allow better outcomes when combined with subsequent PK. PMID:25829823

  10. Evaluation of respiratory model employing conventional NIH mice to access the immunity induced by cellular and acellular pertussis vaccines.

    PubMed

    Dias, Alexandre Alves de Souza de Oliveira; Boller, Maria Aparecida Affonso; Werneck, Lúcia Maria Correa; Hirata Junior, Raphael; Mattos-Guaraldi, Ana Luíza

    2006-11-01

    The increasing number of pertussis cases reported on the last twenty years and the existence of new acellular vaccines reinforce the need of research for experimental models to assure the quality of available pertussis vaccines. In this study, allotments of whole-cell and acellular pertussis vaccines were tested through the Intranasal Challenge Model (INM) using conventional NIH mice. The results have been compared to those achieved by the "Gold standard" Intracerebral Challenge Model (ICM). In contrast to ICM, INM results did not show intralaboratorial variations. Statistical analysis by Anova and Ancova tests revealed that the INM presented reproducibility and allowed identification and separation of different products, including three-component and four-component accellular pertussis vaccines. INM revealed differences between pertussis vaccines. INM provides lower distress to the mice allowing the reduction of mice number including the possibility of using conventional mice (less expensive) under non-aseptic environment. Thus, INM may be used as an alternative method of verifying the consistence of allotment production, including acellular pertussis vaccines. PMID:17160282

  11. Healing rates for challenging rotator cuff tears utilizing an acellular human dermal reinforcement graft

    PubMed Central

    Agrawal, Vivek

    2012-01-01

    Purpose: This study presents a retrospective case series of the clinical and structural outcomes (1.5 T MRI) of arthroscopic rotator cuff repair with acellular human dermal graft reinforcement performed by a single surgeon in patients with large, massive, and previously repaired rotator cuff tears. Materials and Methods: Fourteen patients with mean anterior to posterior tear size 3.87 ± 0.99 cm (median 4 cm, range 2.5–6 cm) were enrolled in the study and were evaluated for structural integrity using a high-field (1.5 T) MRI at an average of 16.8 months after surgery. The Constant-Murley scores, the Flexilevel Scale of Shoulder Function (Flex SF), scapular plane abduction, and strength were analyzed. Results: MRI results showed that the rotator cuff repair was intact in 85.7% (12/14) of the patients studied. Two patients had a Sugaya Type IV recurrent tear (2 of 14; 14.3%), which were both less than 1 cm. The Constant score increased from a preoperative mean of 49.72 (range 13–74) to a postoperative mean of 81.07 (range 45–92) (P value = 0.009). Flexilevel Scale of Shoulder Function (Flex SF) Score normalized to a 100-point scale improved from a preoperative mean of 53.69 to a postoperative mean of 79.71 (P value = 0.003). The Pain Score improved from a preoperative mean of 7.73 to a postoperative mean of 13.57 (P value = 0.008). Scapular plane abduction improved from a preoperative mean of 113.64° to a postoperative mean of 166.43° (P value = 0.010). The strength subset score improved from a preoperative mean of 1.73 kg to a postoperative mean of 7.52 kg (P value = 0.006). Conclusions: This study presents a safe and effective technique that may help improve the healing rates of large, massive, and revision rotator cuff tears with the use of an acellular human dermal allograft. This technique demonstrated favorable structural healing rates and statistically improved functional outcomes in the near term. Level of Evidence: 4. Retrospective case series. PMID

  12. Bone quality and bone strength: benefits of the bone-forming approach

    PubMed Central

    Iolascon, Giovanni; Frizzi, Laura; Di Pietro, Gioconda; Capaldo, Annarita; Luciano, Fabrizio; Gimigliano, Francesca

    2014-01-01

    Summary The ability of bone to resist fracture depends on the intrinsic properties of the materials that comprise the bone matrix mineralization, the amount of bone (i.e. mass), and the spatial distribution of the bone mass (i.e. microarchitecture). Antiresorptive agents may prevent the decay of cancellous bone and cortical thinning, with no improvement of bone microstructure, leading to a partial correction of the principal bone quality defect in osteoporosis, the disruption of trabecular microarchitecture. Anabolic agents promote bone formation at both trabecular and endocortical surfaces, resulting in an increase of cancellous bone volume and cortical thickness. The improvement of cortical bone strength may be limited by an increase in cortical porosity. strontium ranelate improves trabecular network and cortical thickness that will contribute to anti-fracture efficacy at both vertebral and non-vertebral sites. The results of clinical and experimental studies are consistent with the mode of action of strontium involving dissociation between bone formation and resorption leading to a stimulation both trabecular and cortical bone formation without increasing cortical porosity. PMID:25002875

  13. Transcutaneous Raman Spectroscopy of Bone

    NASA Astrophysics Data System (ADS)

    Maher, Jason R.

    Clinical diagnoses of bone health and fracture risk typically rely upon measurements of bone density or structure, but the strength of a bone is also dependent upon its chemical composition. One technology that has been used extensively in ex vivo, exposed-bone studies to measure the chemical composition of bone is Raman spectroscopy. This spectroscopic technique provides chemical information about a sample by probing its molecular vibrations. In the case of bone tissue, Raman spectra provide chemical information about both the inorganic mineral and organic matrix components, which each contribute to bone strength. To explore the relationship between bone strength and chemical composition, our laboratory has contributed to ex vivo, exposed-bone animal studies of rheumatoid arthritis, glucocorticoid-induced osteoporosis, and prolonged lead exposure. All of these studies suggest that Raman-based predictions of biomechanical strength may be more accurate than those produced by the clinically-used parameter of bone mineral density. The utility of Raman spectroscopy in ex vivo, exposed-bone studies has inspired attempts to perform bone spectroscopy transcutaneously. Although the results are promising, further advancements are necessary to make non-invasive, in vivo measurements of bone that are of sufficient quality to generate accurate predictions of fracture risk. In order to separate the signals from bone and soft tissue that contribute to a transcutaneous measurement, we developed an overconstrained extraction algorithm that is based upon fitting with spectral libraries derived from separately-acquired measurements of the underlying tissue components. This approach allows for accurate spectral unmixing despite the fact that similar chemical components (e.g., type I collagen) are present in both soft tissue and bone and was applied to experimental data in order to transcutaneously detect, to our knowledge for the first time, age- and disease-related spectral

  14. SILICON AND BONE HEALTH

    PubMed Central

    JUGDAOHSINGH, R.

    2009-01-01

    Low bone mass (osteoporosis) is a silent epidemic of the 21st century, which presently in the UK results in over 200,000 fractures annually at a cost of over one billion pounds. Figures are set to increase worldwide. Understanding the factors which affect bone metabolism is thus of primary importance in order to establish preventative measures or treatments for this condition. Nutrition is an important determinant of bone health, but the effects of the individual nutrients and minerals, other than calcium, is little understood. Accumulating evidence over the last 30 years strongly suggest that dietary silicon is beneficial to bone and connective tissue health and we recently reported strong positive associations between dietary Si intake and bone mineral density in US and UK cohorts. The exact biological role(s) of silicon in bone health is still not clear, although a number of possible mechanisms have been suggested, including the synthesis of collagen and/or its stabilization, and matrix mineralization. This review gives an overview of this naturally occurring dietary element, its metabolism and the evidence of its potential role in bone health. PMID:17435952

  15. Parallel mechanisms suppress cochlear bone remodeling to protect hearing.

    PubMed

    Jáuregui, Emmanuel J; Akil, Omar; Acevedo, Claire; Hall-Glenn, Faith; Tsai, Betty S; Bale, Hrishikesh A; Liebenberg, Ellen; Humphrey, Mary Beth; Ritchie, Robert O; Lustig, Lawrence R; Alliston, Tamara

    2016-08-01

    Bone remodeling, a combination of bone resorption and formation, requires precise regulation of cellular and molecular signaling to maintain proper bone quality. Whereas osteoblasts deposit and osteoclasts resorb bone matrix, osteocytes both dynamically resorb and replace perilacunar bone matrix. Osteocytes secrete proteases like matrix metalloproteinase-13 (MMP13) to maintain the material quality of bone matrix through perilacunar remodeling (PLR). Deregulated bone remodeling impairs bone quality and can compromise hearing since the auditory transduction mechanism is within bone. Understanding the mechanisms regulating cochlear bone provides unique ways to assess bone quality independent of other aspects that contribute to bone mechanical behavior. Cochlear bone is singular in its regulation of remodeling by expressing high levels of osteoprotegerin. Since cochlear bone expresses a key PLR enzyme, MMP13, we examined whether cochlear bone relies on, or is protected from, osteocyte-mediated PLR to maintain hearing and bone quality using a mouse model lacking MMP13 (MMP13(-/-)). We investigated the canalicular network, collagen organization, lacunar volume via micro-computed tomography, and dynamic histomorphometry. Despite finding defects in these hallmarks of PLR in MMP13(-/-) long bones, cochlear bone revealed no differences in these markers, nor hearing loss as measured by auditory brainstem response (ABR) or distortion product oto-acoustic emissions (DPOAEs), between wild type and MMP13(-/-) mice. Dynamic histomorphometry revealed abundant PLR by tibial osteocytes, but near absence in cochlear bone. Cochlear suppression of PLR corresponds to repression of several key PLR genes in the cochlea relative to long bones. These data suggest that cochlear bone uniquely maintains bone quality and hearing independent of MMP13-mediated osteocytic PLR. Furthermore, the cochlea employs parallel mechanisms to inhibit remodeling by osteoclasts and osteoblasts, and by

  16. Short bones

    MedlinePlus

    Short bones in the human body are often cube-like, their length, width, and height are all about the same. Short bones include the carpal bones of the hands and wrist, and the tarsal bones of the feet and ankles.

  17. Overview of currently available Japanese acellular pertussis vaccines and future problems.

    PubMed

    Kamiya, H; Nii, R

    1988-01-01

    Acellular pertussis diphtheria, tetanus vaccine (APDT) was licensed in 1981 in Japan. This vaccine contains pertussis toxin (PT), filamentous hemagglutinin (FHA) and agglutinogen (AGG) as the main protective antigens. The new APDT vaccine produced by each company differs slightly in composition. There are two representative types of vaccine. One vaccine (B type) contains PT and FHA in a ratio of 1 to 1 and the other one (T type) contains PT and FHA in a ratio of 4 to 1 or 9 to 1 and also contains different amounts of AGG. We have been comparing the effectiveness of these two types of vaccine. The adverse reactions of APDT were local reactions such as redness and swelling, with a few febrile cases. No central nervous system adverse reactions were observed. The antibody protective level of this vaccine is also being investigated. After we changed from conventional vaccine to APDT, the frequency of serious adverse reactions was reduced and the number of pertussis infections also gradually decreased. This vaccine should be used for the children world-wide. PMID:3273618

  18. Calcification resistance for photooxidatively crosslinked acellular bovine jugular vein conduits in right-side heart implantation.

    PubMed

    Lü, Wei-Dong; Wang, An-Ping; Wu, Zhong-Shi; Zhang, Ming; Hu, Tie-Hui; Lei, Guang-Yan; Hu, Ye-Rong

    2012-10-01

    This study aimed to investigate the effect of decellularization plus photooxidative crosslinking and ethanol pretreatment on bioprosthetic tissue calcification. Photooxidatively crosslinked acellular (PCA) bovine jugular vein conduits (BJVCs) and their photooxidized controls (n = 5 each) were sterilized in a graded concentration of ethanol solutions for 4 h, and used to reconstruct dog right ventricular outflow tracts. At 1-year implantation, echocardiography showed similar hemodynamic performance, but obvious calcification for the photooxidized BJVC walls. Further histological examination showed intense calcium deposition colocalized with slightly degraded elastic fibers in the photooxidized BJVC walls, with sparsely distributed punctate calcification in the valves and other areas of walls. But PCA BJVCs had apparent degradation of elastic fibers in the walls, with only sparsely distributed punctate calcification in the walls and valves. Content assay demonstrated comparable calcium content for the two groups at preimplantation, whereas less calcium for the PCA group in the walls and similar calcium in the valvular leaflets compared with the photooxidized group at 1-year retrieval. Elastin content assay presented the conduit walls of PCA group had less elastin content at preimplantation, but similar content at 1-year retrieval compared with the photooxidized group. Phospholipid analysis showed phospholipid extraction by ethanol for the PCA group was more efficacious than the photooxidized group. These results indicate that PCA BJVCs resist calcification in right-side heart implantation owing to decellularization, further photooxidative crosslinking, and subsequent phospholipid extraction by ethanol at preimplantation. PMID:22615255

  19. Brainless but Multi-Headed: Decision Making by the Acellular Slime Mould Physarum polycephalum.

    PubMed

    Beekman, Madeleine; Latty, Tanya

    2015-11-20

    Because of its peculiar biology and the ease with which it can be cultured, the acellular slime mould Physarum polycephalum has long been a model organism in a range of disciplines. Due to its macroscopic, syncytial nature, it is no surprise that it has been a favourite amongst cell biologists. Its inclusion in the experimental tool kit of behavioural ecologists is much more recent. These recent studies have certainly paid off. They have shown that, for an organism that lacks a brain or central nervous system, P. polycephalum shows rather complex behaviour. For example, it is capable of finding the shortest path through a maze, it can construct networks as efficient as those designed by humans, it can solve computationally difficult puzzles, it makes multi-objective foraging decisions, it balances its nutrient intake and it even behaves irrationally. Are the slime mould's achievements simply "cute", worthy of mentioning in passing but nothing to take too seriously? Or do they hint at the fundamental processes underlying all decision making? We will address this question after reviewing the decision-making abilities of the slime mould. PMID:26189159

  20. Three-dimensional Reconstruction of the Microstructure of Human Acellular Nerve Allograft.

    PubMed

    Zhu, Shuang; Zhu, Qingtang; Liu, Xiaolin; Yang, Weihong; Jian, Yutao; Zhou, Xiang; He, Bo; Gu, Liqiang; Yan, Liwei; Lin, Tao; Xiang, Jianping; Qi, Jian

    2016-01-01

    The exact inner 3D microstructure of the human peripheral nerve has been a mystery for decades. Therefore, it has been difficult to solve several problems regarding peripheral nerve injury and repair. We used high-resolution X-ray computed microtomography (microCT) to scan a freeze-dried human acellular nerve allograft (hANA). The microCT images were then used to reconstruct a 3D digital model, which was used to print a 3D resin model of the nerve graft. The 3D digital model of the hANA allowed visualization of all planes. The magnified 3D resin model clearly showed the nerve bundles and basement membrane tubes of the hANA. Scanning electron microscopy (SEM) was used to analyse the microstructure of the hANA. Compared to the SEM images, the microCT image clearly demonstrated the microstructure of the hANA cross section at a resolution of up to 1.2 μm. The 3D digital model of the hANA facilitates a clear and easy understanding of peripheral nerve microstructure. Furthermore, the enlarged 3D resin model duplicates the unique inner structure of each individual hANA. This is a crucial step towards achieving 3D printing of a hANA or nerve that can be used as a nerve graft. PMID:27476584

  1. Three-dimensional Reconstruction of the Microstructure of Human Acellular Nerve Allograft

    PubMed Central

    Zhu, Shuang; Zhu, Qingtang; Liu, Xiaolin; Yang, Weihong; Jian, Yutao; Zhou, Xiang; He, Bo; Gu, Liqiang; Yan, Liwei; Lin, Tao; Xiang, Jianping; Qi, Jian

    2016-01-01

    The exact inner 3D microstructure of the human peripheral nerve has been a mystery for decades. Therefore, it has been difficult to solve several problems regarding peripheral nerve injury and repair. We used high-resolution X-ray computed microtomography (microCT) to scan a freeze-dried human acellular nerve allograft (hANA). The microCT images were then used to reconstruct a 3D digital model, which was used to print a 3D resin model of the nerve graft. The 3D digital model of the hANA allowed visualization of all planes. The magnified 3D resin model clearly showed the nerve bundles and basement membrane tubes of the hANA. Scanning electron microscopy (SEM) was used to analyse the microstructure of the hANA. Compared to the SEM images, the microCT image clearly demonstrated the microstructure of the hANA cross section at a resolution of up to 1.2 μm. The 3D digital model of the hANA facilitates a clear and easy understanding of peripheral nerve microstructure. Furthermore, the enlarged 3D resin model duplicates the unique inner structure of each individual hANA. This is a crucial step towards achieving 3D printing of a hANA or nerve that can be used as a nerve graft. PMID:27476584

  2. Purification design and practice for pertactin, the third component of acellular pertussis vaccine, from Bordetella pertussis.

    PubMed

    Li, Zenglan; Zhang, Yan; Wang, Qi; Li, Zhengjun; Liu, Yongdong; Zhang, Songping; Zhang, Guifeng; Ma, Guanghui; Luo, Jian; Su, Zhiguo

    2016-07-25

    Development of acellular pertussis vaccine (aPV) requires purification of several components from Bordetella pertussis. While the components pertussis toxin (PT) and filamentous hemagglutinin (FHA) have been successfully purified, the third component, pertactin, proves to be a difficult target due to its very low concentration. In order to solve its purification problem, we performed the surface potential analysis with GRASP2 program. The results demonstrated that there are two major charge patches, one negative and one positive, which are located separately on this linear protein. For this special feature, we designed a dual ion exchange chromatography strategy including an anionic exchange and a cationic exchange process for separation of pertactin from the heat extract of B. pertussis. The initial anionic exchange chromatography concentrated the product from 1.7% to 14.6%, with recovery of 80%. The second cationic exchange chromatography increased the purity to 33%, with recovery of 83%. The final purification was accomplished by hydrophobic interaction chromatography, yielding a purity of 96%. The total recovery of the three columns was 61%. Characterization of the purified antigen was performed with CD, intrinsic fluorescence, HP-SEC and western-blot, showing that the purified protein kept its natural conformation and immune-reactivity. The rationally designed process proved to be feasible, and it is suitable for large-scale preparation of the third aPV component pertactin. PMID:27302339

  3. Tetanus, diphtheria, and acellular pertussis vaccination among women of childbearing age-United States, 2013.

    PubMed

    O'Halloran, Alissa C; Lu, Peng-Jun; Williams, Walter W; Ding, Helen; Meyer, Sarah A

    2016-07-01

    The incidence of pertussis in the United States has increased since the 1990s. Tetanus, diphtheria, and acellular pertussis (Tdap) vaccination of pregnant women provides passive protection to infants. Tdap vaccination is currently recommended for pregnant women during each pregnancy, but coverage among pregnant women and women of childbearing age has been suboptimal. Data from the 2013 Behavioral Risk Factor Surveillance System (BRFSS) and 2013 National Health Interview Survey (NHIS) were used to determine national and state-specific Tdap vaccination coverage among women of childbearing age by self-reported pregnancy status at the time of the survey. Although this study could not assess coverage of Tdap vaccination received during pregnancy because questions on whether Tdap vaccination was received during pregnancy were not asked in BRFSS and NHIS, demographic and access-to-care factors associated with Tdap vaccination coverage in this population were assessed. Tdap vaccination coverage among all women 18-44 years old was 38.4% based on the BRFSS and 23.3% based on the NHIS. Overall, coverage did not differ by pregnancy status at the time of the survey. Coverage among all women 18-44 years old varied widely by state. Age, race and ethnicity, education, number of children in the household, and access-to-care characteristics were independently associated with Tdap vaccination in both surveys. We identified associations of demographic and access-to-care characteristics with Tdap vaccination that can guide strategies to improve vaccination rates in women during pregnancy. PMID:27372388

  4. Bone scanning.

    PubMed

    Greenfield, L D; Bennett, L R

    1975-03-01

    Scanning is based on the uptake of a nuclide by the crystal lattice of bone and is related to bone blood flow. Cancer cells do not take up the tracer. Normally, the scan visualizes the highly vascular bones. Scans are useful and are indicated in metastatic bone disease, primary bone tumors, hematologic malignancies and some non-neoplastic diseases. The scan is more sensitive than x-ray in the detection of malignant diseases of the skeleton. PMID:1054210

  5. Determination of osteocalcin in meat and bone meal of bovine and porcine origin using matrix-assisted laser desorption ionization/time-of-flight mass spectrometry and high-resolution hybrid mass spectrometry.

    PubMed

    Balizs, Gabor; Weise, Christoph; Rozycki, Christel; Opialla, Tobias; Sawada, Stefanie; Zagon, Jutta; Lampen, Alfonso

    2011-05-01

    A method has been developed for determining the origin of meat and bone meal (MBM) by detecting species-specific osteocalcin (OC) using matrix-assisted laser desorption ionization/time-of-flight (MALDI/TOF) and high-resolution hybrid mass spectrometry (HR-Q/TOF MS). The analysis is based on the detection of typical species-specific OC and its tryptic peptide fragments which differ in mass due to differences in the amino-acid sequences between species. After dissolving the MBM samples in EDTA buffer, purification after ultrafiltration was performed using two methods: solid-phase extraction using Zip-Tip C(18) or size exclusion coupled with reverse-phase chromatography. Fractions containing partially purified intact OC were analyzed using LC-Q/TOF and MALDI/TOF mass spectrometry. Species-specific OC was detected at the typical protonated and doubly protonated molecular ions. Furthermore, typical porcine- and bovine-derived tryptic fragments from MBM were detected after enzymatic digestion. In order to determine the underlying amino-acid sequences and to confirm the assignment to OC-derived peptides, MS/MS analysis was carried out. In conclusion, we were able to detect OC in bovine and porcine MBM with high sensitivity and the MS-based method described here by which total OC mass and marker peptides of digested OC are recorded can be used as an alternative approach to detect genus-specific differences in MBM and can be applied as a confirmatory method to mainly immunological osteocalcin screening methods. PMID:21504815

  6. Evidence for arrested bone formation during spaceflight