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Sample records for bone collagen matrix

  1. Effect of Bio-Oss® Collagen and Collagen Matrix on Bone Formation

    OpenAIRE

    Wong, R.W.K; Rabie, A.B.M

    2010-01-01

    Objective: to compare the amount of new bone produced by Bio-Oss ® Collagen to that produced by collagen matrix in vivo. Method: eighteen bone defects, 5mm by 10mm were created in the parietal bone of 9 New Zealand White rabbits. 6 defects were grafted with Bio-Oss ® Collagen. 6 defects were grafted with collagen matrix alone (positive control) and 6 were left empty (negative control). Animals were killed on day 14 and the defects were dissected and prepared for histological assessment. Quant...

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

    Science.gov (United States)

    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...

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

    Directory of Open Access Journals (Sweden)

    Andreas O. Parashis

    2014-01-01

    Full Text Available 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.

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

    OpenAIRE

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

    2012-01-01

    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...

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

    Science.gov (United States)

    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

  6. Development and Characterization of a Bioinspired Bone Matrix with Aligned Nanocrystalline Hydroxyapatite on Collagen Nanofibers

    Directory of Open Access Journals (Sweden)

    Hsi-Chin Wu

    2016-03-01

    Full Text Available Various kinds of three-dimensional (3D scaffolds have been designed to mimic the biological spontaneous bone formation characteristics by providing a suitable microenvironment for osteogenesis. In view of this, a natural bone-liked composite scaffold, which was combined with inorganic (hydroxyapatite, Hap and organic (type I collagen, Col phases, has been developed through a self-assembly process. This 3D porous scaffold consisting of a c-axis of Hap nanocrystals (nHap aligning along Col fibrils arrangement is similar to natural bone architecture. A significant increase in mechanical strength and elastic modulus of nHap/Col scaffold is achieved through biomimetic mineralization process when compared with simple mixture of collagen and hydroxyapatite method. It is suggested that the self-organization of Hap and Col produced in vivo could also be achieved in vitro. The oriented nHap/Col composite not only possesses bone-like microstructure and adequate mechanical properties but also enhances the regeneration and reorganization abilities of bone tissue. These results demonstrated that biomimetic nHap/Col can be successfully reconstructed as a bone graft substitute in bone tissue engineering.

  7. Distinct Characteristics of Mandibular Bone Collagen Relative to Long Bone Collagen: Relevance to Clinical Dentistry

    Directory of Open Access Journals (Sweden)

    Takashi Matsuura

    2014-01-01

    Full Text Available Bone undergoes constant remodeling throughout life. The cellular and biochemical mechanisms of bone remodeling vary in a region-specific manner. There are a number of notable differences between the mandible and long bones, including developmental origin, osteogenic potential of mesenchymal stem cells, and the rate of bone turnover. Collagen, the most abundant matrix protein in bone, is responsible for determining the relative strength of particular bones. Posttranslational modifications of collagen, such as intermolecular crosslinking and lysine hydroxylation, are the most essential determinants of bone strength, although the amount of collagen is also important. In comparison to long bones, the mandible has greater collagen content, a lower amount of mature crosslinks, and a lower extent of lysine hydroxylation. The great abundance of immature crosslinks in mandibular collagen suggests that there is a lower rate of cross-link maturation. This means that mandibular collagen is relatively immature and thus more readily undergoes degradation and turnover. The greater rate of remodeling in mandibular collagen likely renders more flexibility to the bone and leaves it more suited to constant exercise. As reviewed here, it is important in clinical dentistry to understand the distinctive features of the bones of the jaw.

  8. Instrumented fusion of thoracolumbar fracture with type I mineralized collagen matrix combined with autogenous bone marrow as a bone graft substitute: a four-case report

    OpenAIRE

    Faundez, Antonio; Taylor, Sofia; Kaelin, André

    2006-01-01

    In order to avoid the morbidity from autogenous bone harvesting, bone graft substitutes are being used more frequently in spinal surgery. There is indirect radiological evidence that bone graft substitutes are efficacious in humans. The purpose of this four-case study was to visually, manually, and histologically assess the quality of a fusion mass produced by a collagen hydroxyapatite scaffold impregnated with autologous bone marrow aspirate for posterolateral fusion. Four patients sustained...

  9. Osteomimicry of mammary adenocarcinoma cells in vitro; increased expression of bone matrix proteins and proliferation within a 3D collagen environment.

    Directory of Open Access Journals (Sweden)

    Rachel F Cox

    Full Text Available Bone is the most common site of metastasis for breast cancer, however the reasons for this remain unclear. We hypothesise that under certain conditions mammary cells possess osteomimetic capabilities that may allow them to adapt to, and flourish within, the bone microenvironment. Mammary cells are known to calcify within breast tissue and we have recently reported a novel in vitro model of mammary mineralization using murine mammary adenocarcinoma 4T1 cells. In this study, the osteomimetic properties of the mammary adenocarcinoma cell line and the conditions required to induce mineralization were characterized extensively. It was found that exogenous organic phosphate and inorganic phosphate induce mineralization in a dose dependent manner in 4T1 cells. Ascorbic acid and dexamethasone alone have no effect. 4T1 cells also show enhanced mineralization in response to bone morphogenetic protein 2 in the presence of phosphate supplemented media. The expression of several bone matrix proteins were monitored throughout the process of mineralization and increased expression of collagen type 1 and bone sialoprotein were detected, as determined by real-time RT-PCR. In addition, we have shown for the first time that 3D collagen glycosaminoglycan scaffolds, bioengineered to represent the bone microenvironment, are capable of supporting the growth and mineralization of 4T1 adenocarcinoma cells. These 3D scaffolds represent a novel model system for the study of mammary mineralization and bone metastasis. This work demonstrates that mammary cells are capable of osteomimicry, which may ultimately contribute to their ability to preferentially metastasize to, survive within and colonize the bone microenvironment.

  10. Molecular packing in bone collagen fibrils prior to mineralization

    Science.gov (United States)

    Hsiao, Benjamin; Zhou, Hong-Wen; Burger, Christian; Chu, Benjamin; Glimcher, Melvin J.

    2012-02-01

    The three-dimensional packing of collagen molecules in bone collagen fibrils has been largely unknown because even in moderately mineralized bone tissues, the organic matrix structure is severely perturbed by the deposition of mineral crystals. During the past decades, the structure of tendon collagen (e.g. rat tail) --- a tissue that cannot mineralize in vivo, has been assumed to be representative for bone collagen fibrils. Small-angle X-ray diffraction analysis of the native, uncalcified intramuscular fish bone has revealed a new molecular packing scheme, significantly different from the quasi-hexagonal arrangement often found in tendons. The deduced structure in bone collagen fibrils indicates the presence of spatially discrete microfibrils, and an arrangement of intrafibrillar space to form ``channels'', which could accommodate crystals with dimensions typically found in bone apatite.

  11. High-strength mineralized collagen artificial bone

    Science.gov (United States)

    Qiu, Zhi-Ye; Tao, Chun-Sheng; Cui, Helen; Wang, Chang-Ming; Cui, Fu-Zhai

    2014-03-01

    Mineralized collagen (MC) is a biomimetic material that mimics natural bone matrix in terms of both chemical composition and microstructure. The biomimetic MC possesses good biocompatibility and osteogenic activity, and is capable of guiding bone regeneration as being used for bone defect repair. However, mechanical strength of existing MC artificial bone is too low to provide effective support at human load-bearing sites, so it can only be used for the repair at non-load-bearing sites, such as bone defect filling, bone graft augmentation, and so on. In the present study, a high strength MC artificial bone material was developed by using collagen as the template for the biomimetic mineralization of the calcium phosphate, and then followed by a cold compression molding process with a certain pressure. The appearance and density of the dense MC were similar to those of natural cortical bone, and the phase composition was in conformity with that of animal's cortical bone demonstrated by XRD. Mechanical properties were tested and results showed that the compressive strength was comparable to human cortical bone, while the compressive modulus was as low as human cancellous bone. Such high strength was able to provide effective mechanical support for bone defect repair at human load-bearing sites, and the low compressive modulus can help avoid stress shielding in the application of bone regeneration. Both in vitro cell experiments and in vivo implantation assay demonstrated good biocompatibility of the material, and in vivo stability evaluation indicated that this high-strength MC artificial bone could provide long-term effective mechanical support at human load-bearing sites.

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

    OpenAIRE

    Won, J. E.; Yun, Y. R.; Jang, J. H.; S. H. Yang; Kim, J. H.; W. Chrzanowski; Wall, I. B.; Knowles, J. C.; Kim, H. W.

    2015-01-01

    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 multifunctio...

  13. Long-term voluntary exercise of male mice induces more beneficial effects on cancellous and cortical bone than on the collagenous matrix

    OpenAIRE

    2009-01-01

    Abstract The effects of lifelong physical exercise on the composition, structure and mechanical properties of bone are not well understood. Earlier, we found that voluntary physical exercise improved various properties of bone in maturing male mice up to 6 months of age. In the present study, we extended the previous study to 18 months. Half of the mice (total N=144) had access to running wheels while half were kept sedentary. The collagen network was assessed biochemically and by ...

  14. 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.

    Science.gov (United States)

    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

  15. A collagen-binding EGFR antibody fragment targeting tumors with a collagen-rich extracellular matrix

    OpenAIRE

    Hui Liang; Xiaoran Li; Bin Wang; Bing Chen; Yannan Zhao; Jie Sun; Yan Zhuang; Jiajia Shi; He Shen; Zhijun Zhang; Jianwu Dai

    2016-01-01

    Many tumors over-express collagen, which constitutes the physical scaffold of tumor microenvironment. Collagen has been considered to be a target for cancer therapy. The collagen-binding domain (CBD) is a short peptide, which could bind to collagen and achieve the sustained release of CBD-fused proteins in collagen scaffold. Here, a collagen-binding EGFR antibody fragment was designed and expressed for targeting the collagen-rich extracellular matrix in tumors. The antibody fragment (Fab) of ...

  16. Spectroscopic characterization of collagen cross-links in bone

    Science.gov (United States)

    Paschalis, E. P.; Verdelis, K.; Doty, S. B.; Boskey, A. L.; Mendelsohn, R.; Yamauchi, M.

    2001-01-01

    Collagen is the most abundant protein of the organic matrix in mineralizing tissues. One of its most critical properties is its cross-linking pattern. The intermolecular cross-linking provides the fibrillar matrices with mechanical properties such as tensile strength and viscoelasticity. In this study, Fourier transform infrared (FTIR) spectroscopy and FTIR imaging (FTIRI) analyses were performed in a series of biochemically characterized samples including purified collagen cross-linked peptides, demineralized bovine bone collagen from animals of different ages, collagen from vitamin B6-deficient chick homogenized bone and their age- and sex-matched controls, and histologically stained thin sections from normal human iliac crest biopsy specimens. One region of the FTIR spectrum of particular interest (the amide I spectral region) was resolved into its underlying components. Of these components, the relative percent area ratio of two subbands at approximately 1660 cm(-1) and approximately 1690 cm(-1) was related to collagen cross-links that are abundant in mineralized tissues (i.e., pyridinoline [Pyr] and dehydrodihydroxylysinonorleucine [deH-DHLNL]). This study shows that it is feasible to monitor Pyr and DHLNL collagen cross-links spatial distribution in mineralized tissues. The spectroscopic parameter established in this study may be used in FTIRI analyses, thus enabling the calculation of relative Pyr/DHLNL amounts in thin (approximately 5 microm) calcified tissue sections with a spatial resolution of approximately 7 microm.

  17. Microfibrous {beta}-TCP/collagen scaffolds mimic woven bone in structure and composition

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Shen; Zhang Xin; Cai Qing; Yang Xiaoping [Key Laboratory of Beijing City on Preparation and Processing of Novel Polymer Materials, College of Materials Science and Engineering, Beijing University of Chemical Technology, Beijing 100029 (China); Wang Bo; Deng Xuliang, E-mail: yangxp@mail.buct.edu.c [Department of VIP Dental Service, School and Hospital of Stomatology, Peking University, Beijing 100081 (China)

    2010-12-15

    Woven bone, as the initial form of bone tissue, is always found in developing and repairing bone. It is thought of as a temporary scaffold for the deposition of osteogenic cells and the laying down of lamellar bone. Thus, we hypothesize that a matrix which resembles the architecture and components of woven bone can provide an osteoblastic microenvironment for bone cell growth and new bone formation. In this study, woven-bone-like beta-tricalcium phosphate ({beta}-TCP)/collagen scaffolds were fabricated by sol-gel electrospinning and impregnating methods. Optimization studies on sol-gel synthesis and electrospinning process were conducted respectively to prepare pure {beta}-TCP fibers with dimensions close to mineralized collagen fibrils in woven bone. The collagen-coating layer prepared by impregnation had an adhesive role that held the {beta}-TCP fibers together, and resulted in rapid degradation and matrix mineralization in in vitro tests. MG63 osteoblast-like cells seeded on the resultant scaffolds showed three-dimensional (3D) morphologies, and merged into multicellular layers after 7 days culture. Cytotoxicity test further revealed that extracts from the resultant scaffolds could promote the proliferation of MG63 cells. Therefore, the woven-bone-like matrix that we constructed favored the attachment and proliferation of MG63 cells in three dimensions. It has great potential ability to shorten the time of formation of new bone.

  18. Atomic force microscopy of collagen structure in bone and dentine revealed by osteoclastic resorption

    International Nuclear Information System (INIS)

    Mineralised tissues such as bone consist of two material phases: collagen protein fibrils, secreted by osteoblasts, form model structures for subsequent deposition of mineral, calcium hydroxyapatite. Collagen and mineral are removed in a three-dimensional manner by osteoclasts during bone turnover in skeletal growth or repair. Bone active drugs have recently been developed for skeletal diseases, and there is revived interest in changes in the structure of mineralised tissues seen in disease and upon treatment. The resolution of atomic force microscopy and use of unmodified samples has enabled us to image bone and dentine collagen exposed by the natural process of cellular dissolution of mineralised matrix. The morphology of bone and dentine has been analysed when fully mineralised and after osteoclast-mediated bone resorption, and compared with results from other microscopy techniques. Banded type I collagen, with 66.5±1.4 nm axial D-periodicity and 62.2±7.0 nm diameter, has been identified within resorption lacunae in bone and 69.4±4.3 nm axial D-periodicity and 140.6±12.4 nm diameter in dentine substrates formed by human and rabbit osteoclasts, respectively. This observation suggests a route by which the material and morphological properties of bone collagen can be analysed in situ, compared with collagen from non-skeletal sites, and contrasted in diseases of medical importance, such as osteoporosis, where skeletal tissue is mechanically weakened

  19. Type VI Collagen Regulates Dermal Matrix Assembly and Fibroblast Motility.

    Science.gov (United States)

    Theocharidis, Georgios; Drymoussi, Zoe; Kao, Alexander P; Barber, Asa H; Lee, David A; Braun, Kristin M; Connelly, John T

    2016-01-01

    Type VI collagen is a nonfibrillar collagen expressed in many connective tissues and implicated in extracellular matrix (ECM) organization. We hypothesized that type VI collagen regulates matrix assembly and cell function within the dermis of the skin. In the present study we examined the expression pattern of type VI collagen in normal and wounded skin and investigated its specific function in new matrix deposition by human dermal fibroblasts. Type VI collagen was expressed throughout the dermis of intact human skin, at the expanding margins of human keloid samples, and in the granulation tissue of newly deposited ECM in a mouse model of wound healing. Generation of cell-derived matrices (CDMs) by human dermal fibroblasts with stable knockdown of COL6A1 revealed that type VI collagen-deficient matrices were significantly thinner and contained more aligned, thicker, and widely spaced fibers than CDMs produced by normal fibroblasts. In addition, there was significantly less total collagen and sulfated proteoglycans present in the type VI collagen-depleted matrices. Normal fibroblasts cultured on de-cellularized CDMs lacking type VI collagen displayed increased cell spreading, migration speed, and persistence. Taken together, these findings indicate that type VI collagen is a key regulator of dermal matrix assembly, composition, and fibroblast behavior and may play an important role in wound healing and tissue regeneration. PMID:26763426

  20. Mechanical properties and osteogenic potential of hydroxyapatite-PLGA-collagen biomaterial for bone regeneration.

    Science.gov (United States)

    Bhuiyan, Didarul B; Middleton, John C; Tannenbaum, Rina; Wick, Timothy M

    2016-08-01

    A bone graft is a complicated structure that provides mechanical support and biological signals that regulate bone growth, reconstruction, and repair. A single-component material is inadequate to provide a suitable combination of structural support and biological stimuli to promote bone regeneration. Multicomponent composite biomaterials lack adequate bonding among the components to prevent phase separation after implantation. We have previously developed a novel multistep polymerization and fabrication process to construct a nano-hydroxyapatite-poly(D,L-lactide-co-glycolide)-collagen biomaterial (abbreviated nHAP-PLGA-collagen) with the components covalently bonded to each other. In the present study, the mechanical properties and osteogenic potential of nHAP-PLGA-collagen are characterized to assess the material's suitability to support bone regeneration. nHAP-PLGA-collagen films exhibit tensile strength very close to that of human cancellous bone. Human mesenchymal stem cells (hMSCs) are viable on 2D nHAP-PLGA-collagen films with a sevenfold increase in cell population after 7 days of culture. Over 5 weeks of culture, hMSCs deposit matrix and mineral consistent with osteogenic differentiation and bone formation. As a result of matrix deposition, nHAP-PLGA-collagen films cultured with hMSCs exhibit 48% higher tensile strength and fivefold higher moduli compared to nHAP-PLGA-collagen films without cells. More interestingly, secretion of matrix and minerals by differentiated hMSCs cultured on the nHAP-PLGA-collagen films for 5 weeks mitigates the loss of mechanical strength that accompanies PLGA hydrolysis. PMID:27120980

  1. MT1-MMP and type II collagen specify skeletal stem cells and their bone and cartilage progeny

    DEFF Research Database (Denmark)

    Szabova, L.; Yamada, S.S.; Wimer, H.;

    2009-01-01

    Skeletal formation is dependent on timely recruitment of skeletal stem cells and their ensuing synthesis and remodeling of the major fibrillar collagens, type I collagen and type II collagen, in bone and cartilage tissues during development and postnatal growth. Loss of the major collagenolytic...... activity associated with the membrane-type 1 matrix metalloproteinase (MT1-MMP) results in disrupted skeletal development and growth in both cartilage and bone, where MT1-MMP is required for pericellular collagen dissolution. We show here that reconstitution of MT1-MMP activity in the type II collagen......-expressing cells of the skeleton rescues not only diminished chondrocyte proliferation, but surprisingly, also results in amelioration of the severe skeletal dysplasia associated with MT1-MMP deficiency through enhanced bone formation. Consistent with this increased bone formation, type II collagen was identified...

  2. Induction of Bone Matrix Protein Expression by Native Bone Matrix Proteins in C2C12 Culture

    Institute of Scientific and Technical Information of China (English)

    ZHEN-MING HU; SEAN A. F. PEEL; STEPHEN K. C. HO; GEORGE K. B. SANDOR; CAMERON M. L. CLOKIE

    2009-01-01

    Objective To study the expression of bone matrix protein (BMP) induced by bovine bone morphogenetic proteins (BMPs) in vitro. Methods Type I collagen, osteopontin (OPN), osteonectin (ON), osteocalcin (OC), and bone sialoprotein (BSP) were detected by immunohistochemistry in C2C12 cultured from day 1 to day 28. Results The signaling of bone matrix protein expression became weaker except for type I collagen, OC and BSP after 5 days. Fourteen days after culture, the positive signaling of type I collagen, OPN, ON, OC, and BSP was gradually declined, and could be detected significantly as compared with that of the negative control on day 28. BMP assay showed that the Ikaline phosphatase (ALP) activity was higher in C2C12 culture than in the control during the 14-day culture. Also, total protein and DNA significantly increased during the 14-day culture. High levels of ALP were seen in preosteoblasts and osteoblsts in vivo and in differentiating ostcoblasts in vitro. ALP was well recognized as a marker reflecting osteoblastic activity. Conclusion Native bovine BMP induces conversion of myoblasts into osteoblasts, produces type 1 collagen, and plays significantly role in osteoinduction and bone matrix mineralization of C2C12 in vitro.

  3. Crosslinked collagen/chitosan matrix for artificial livers

    NARCIS (Netherlands)

    Wang, X.H.; Li, D.P.; Wang, W.J.; Feng, Q.L.; Cui, F.Z.; Xu, Y.X.; Song, X.H.; Werf, van der Mark

    2003-01-01

    Matrices composed of collagen and chitosan may create an appropriate environment for the regeneration of livers. In this study, we have prepared, characterized and evaluated a new collagen/chitosan matrix (CCM). The CCM was made by using crosslinking agent 1-ethyl-3-(3-dimethylaminopropyl)-carbodiim

  4. Tuning 3D Collagen Matrix Stiffness Independently of Collagen Concentration Modulates Endothelial Cell Behavior

    Science.gov (United States)

    Mason, Brooke N.; Starchenko, Alina; Williams, Rebecca M.; Bonassar, Lawrence J.; Reinhart-King, Cynthia A.

    2012-01-01

    Numerous studies have described the effects of matrix stiffening on cell behavior using two dimensional (2D) synthetic surfaces; however less is known about the effects of matrix stiffening on cells embedded in three dimensional (3D) in vivo-like matrices. A primary limitation in investigating the effects of matrix stiffness in 3D is the lack of materials that can be tuned to control stiffness independently of matrix density. Here, we use collagen-based scaffolds where the mechanical properties are tuned using non-enzymatic glycation of the collagen in solution, prior to polymerization. Collagen solutions glycated prior to polymerization result in collagen gels with a 3-fold increase in compressive modulus without significant changes to the collagen architecture. Using these scaffolds, we show that endothelial cell spreading increases with matrix stiffness, as does the number and length of angiogenic sprouts and the overall spheroid outgrowth. Differences in sprout length are maintained even when the receptor for advanced glycation endproducts is inhibited. Our results demonstrate the ability to de-couple matrix stiffness from matrix density and structure in collagen gels, and that increased matrix stiffness results in increased sprouting and outgrowth. PMID:22902816

  5. Fabrication of polycaprolactone collagen hydrogel constructs seeded with mesenchymal stem cells for bone regeneration

    Energy Technology Data Exchange (ETDEWEB)

    Reichert, J C; Berner, A [Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane (Australia); Heymer, A; Eulert, J; Noeth, U, E-mail: johannes.reichert@qut.edu.a [Orthopaedic Institute, Division of Tissue Engineering, Koenig-Ludwig-Haus, Julius-Maximilians-University, Wuerzburg (Germany)

    2009-12-15

    The osteogenic differentiation of bone marrow-derived human mesenchymal stem cells (MSCs) in a collagen I hydrogel was investigated. Collagen hydrogels with 7.5 x 10{sup 5} MSCs ml{sup -1} were fabricated and cultured for 6 weeks in a defined, osteogenic differentiation medium. Histochemistry revealed morphologically distinct, chondrocyte-like cells, surrounded by a sulfated proteoglycan-rich extracellular matrix in the group treated with bone morphogenetic protein 2 (BMP-2), while cells cultured with dexamethasone, ascorbate-2-phosphate, and beta-glycerophosphate displayed a spindle-shaped morphology and deposited a mineralized matrix. Real-time polymerase chain reaction (RT-PCR) analyses revealed a specific chondrogenic differentiation with the expression of cartilage-specific markers in the BMP-2-treated group and a distinct expression pattern of the osteogenic markers alkaline phosphatase (ALP), type I collagen, osteocalcin (OC), and cbfa-1 in the group treated with an osteogenic standard medium. The collagen gels were used to engineer a cell laden medical grade epsilon-polycaprolactone (PCL)-hydrogel construct for segmental bone repair showing good bonding at the scaffold hydrogel interface and even cell distribution. The results show that MSCs cultured in a collagen I hydrogel are able to undergo a distinct osteogenic differentiation pathway when stimulated with specific differentiation factors and suggest that collagen I hydrogels are a suitable means to facilitate cell seeding of scaffolds for bone tissue engineering applications.

  6. Shrinking mechanism of a porous collagen matrix immersed in solution.

    Science.gov (United States)

    Chen, Po-Yang; Hsieh, Hsyue-Jen; Huang, Lynn L H

    2014-12-01

    The porous structure of collagen-based matrices enables the infiltration of cells both in in vitro and clinical applications. Reconstituted porous collagen matrices often collapse when they are in contact with aqueous solutions; however, the mechanism for the collapse of the pores is not understood. We, therefore, investigated the interactions between the collagen matrix and different solutions, and discuss the mechanisms for the change in microstructure of the matrix on immersing it in solution. When a dried collagen matrix was immersed in aqueous solutions, the matrix shrunk and pores close to the surface closed. The shrinkage ratio and thickness of the compact microstructure close to the superficial area decreased with increasing ethanol content in the solution. The original porous structure of the collagen matrix was preserved when the matrix was immersed in absolute ethanol. The shrinkage of a porous collagen matrix in contact with aqueous solutions was attributed to the liquid/gas interfacial tension. The average pore diameter of the matrix also significantly affected the shrinkage of the matrix. The shrinkage of the matrix, explained using the Young-Laplace equation, was found to result from the pressure drop, and especially in the pores located superficially, leading to the collapse of the matrix microstructure. The integrity of the porous microstructure allows better penetration of cells in medical applications. The numbers of NIH/3T3 fibroblasts penetrated through the hydrated Col/PBS porous collagen matrices pre-immersed in absolute ethanol with subsequent water and DMEM culture medium replacements were significantly higher than those through matrices hydrated directly in DMEM.

  7. Shrinking mechanism of a porous collagen matrix immersed in solution.

    Science.gov (United States)

    Chen, Po-Yang; Hsieh, Hsyue-Jen; Huang, Lynn L H

    2014-12-01

    The porous structure of collagen-based matrices enables the infiltration of cells both in in vitro and clinical applications. Reconstituted porous collagen matrices often collapse when they are in contact with aqueous solutions; however, the mechanism for the collapse of the pores is not understood. We, therefore, investigated the interactions between the collagen matrix and different solutions, and discuss the mechanisms for the change in microstructure of the matrix on immersing it in solution. When a dried collagen matrix was immersed in aqueous solutions, the matrix shrunk and pores close to the surface closed. The shrinkage ratio and thickness of the compact microstructure close to the superficial area decreased with increasing ethanol content in the solution. The original porous structure of the collagen matrix was preserved when the matrix was immersed in absolute ethanol. The shrinkage of a porous collagen matrix in contact with aqueous solutions was attributed to the liquid/gas interfacial tension. The average pore diameter of the matrix also significantly affected the shrinkage of the matrix. The shrinkage of the matrix, explained using the Young-Laplace equation, was found to result from the pressure drop, and especially in the pores located superficially, leading to the collapse of the matrix microstructure. The integrity of the porous microstructure allows better penetration of cells in medical applications. The numbers of NIH/3T3 fibroblasts penetrated through the hydrated Col/PBS porous collagen matrices pre-immersed in absolute ethanol with subsequent water and DMEM culture medium replacements were significantly higher than those through matrices hydrated directly in DMEM. PMID:24678021

  8. Collagen-derived markers of bone metabolism in osteogenesis imperfecta

    DEFF Research Database (Denmark)

    Lund, A M; Hansen, M; Kollerup, Gina Birgitte;

    1998-01-01

    Markers of bone formation [C-terminal and N-terminal propeptides of procollagen I (PICP, PINP), osteocalcin and alkaline phosphatase] and bone resorption [C-terminal cross-linked telopeptide of collagen I (ICTP) and hydroxypyridinium cross-links, pyridinoline (Pyr) and deoxypyridinoline (Dpyr......)] were measured in 78 osteogenesis imperfecta (OI) patients to investigate bone metabolism in vivo and relate marker concentrations to phenotype and in vitro collagen I defects, as shown by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE). PICP and PINP were generally low, and the...... serum levels were lower in all children and adults with mild OI and a quantitative collagen defect than in patients with severe OI and a qualitative collagen I defect. ICTP, Pyr and Dpyr were generally normal or reduced, but elevated in severely affected adults with a qualitative collagen I defect. The...

  9. Collagens and proteoglycans of the corneal extracellular matrix

    Directory of Open Access Journals (Sweden)

    Y.M. Michelacci

    2003-08-01

    Full Text Available The cornea is a curved and transparent structure that provides the initial focusing of a light image into the eye. It consists of a central stroma that constitutes 90% of the corneal depth, covered anteriorly with epithelium and posteriorly with endothelium. Its transparency is the result of the regular spacing of collagen fibers with remarkably uniform diameter and interfibrillar space. Corneal collagen is composed of heterotypic fibrils consisting of type I and type V collagen molecules. The cornea also contains unusually high amounts of type VI collagen, which form microfibrillar structures, FACIT collagens (XII and XIV, and other nonfibrillar collagens (XIII and XVIII. FACIT collagens and other molecules, such as leucine-rich repeat proteoglycans, play important roles in modifying the structure and function of collagen fibrils.Proteoglycans are macromolecules composed of a protein core with covalently linked glycosaminoglycan side chains. Four leucine-rich repeat proteoglycans are present in the extracellular matrix of corneal stroma: decorin, lumican, mimecan and keratocan. The first is a dermatan sulfate proteoglycan, and the other three are keratan sulfate proteoglycans. Experimental evidence indicates that the keratan sulfate proteoglycans are involved in the regulation of collagen fibril diameter, and dermatan sulfate proteoglycan participates in the control of interfibrillar spacing and in the lamellar adhesion properties of corneal collagens. Heparan sulfate proteoglycans are minor components of the cornea, and are synthesized mainly by epithelial cells. The effect of injuries on proteoglycan synthesis is discussed.

  10. Enhanced osteoprogenitor elongated collagen fiber matrix formation by bioactive glass ionic silicon dependent on Sp7 (osterix) transcription.

    Science.gov (United States)

    Varanasi, Venu G; Odatsu, Tetsurou; Bishop, Timothy; Chang, Joyce; Owyoung, Jeremy; Loomer, Peter M

    2016-10-01

    Bioactive glasses release ions, those enhance osteoblast collagen matrix synthesis and osteogenic marker expression during bone healing. Collagen matrix density and osteogenic marker expression depend on osteogenic transcription factors, (e.g., Osterix (OSX)). We hypothesize that enhanced expression and formation of collagen by Si(4+) depends on enhanced expression of OSX transcription. Experimental bioactive glass (6P53-b) and commercial Bioglass(TM) (45S5) were dissolved in basal medium to make glass conditioned medium (GCM). ICP-MS analysis was used to measure bioactive glass ion release rates. MC3T3-E1 cells were cultured for 20 days, and gene expression and extracellular matrix collagen formation was analyzed. In a separate study, siRNA was used to determine the effect of OSX knockdown on impacting the effect of Si(4+) on osteogenic markers and matrix collagen formation. Each bioactive glass exhibited similar ion release rates for all ions, except Mg(2+) released by 6P53-b. Gene expression results showed that GCM markedly enhanced many osteogenic markers, and 45S5 GCM showed higher levels of expression and collagen matrix fiber bundle density than 6P53-b GCM. Upon knockdown of OSX transcription, collagen type 5, alkaline phosphatase, and matrix density were not enhanced as compared to wild type cells. This study illustrates that the enhancement of elongated collagen fiber matrix formation by Si(±) depends on OSX transcription. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 2604-2615, 2016.

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

    Science.gov (United States)

    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

  12. Effect of collagen sponge and fibrin glue on bone repair

    Science.gov (United States)

    SANTOS, Thiago de Santana; ABUNA, Rodrigo Paolo Flores; de ALMEIDA, Adriana Luisa Gonçalves; BELOTI, Marcio Mateus; ROSA, Adalberto Luiz

    2015-01-01

    ABSTRACT The ability of hemostatic agents to promote bone repair has been investigated using in vitro and in vivo models but, up to now, the results are inconclusive. Objective In this context, the aim of this study was to compare the potential of bone repair of collagen sponge with fibrin glue in a rat calvarial defect model. Material and Methods Defects of 5 mm in diameter were created in rat calvariae and treated with either collagen sponge or fibrin glue; untreated defects were used as control. At 4 and 8 weeks, histological analysis and micro-CT-based histomorphometry were carried out and data were compared by two-way ANOVA followed by Student-Newman-Keuls test when appropriated (p≤0.05). Results Three-dimensional reconstructions showed increased bone formation in defects treated with either collagen sponge or fibrin glue compared with untreated defects, which was confirmed by the histological analysis. Morphometric parameters indicated the progression of bone formation from 4 to 8 weeks. Additionally, fibrin glue displayed slightly higher bone formation rate when compared with collagen sponge. Conclusion Our results have shown the benefits of using collagen sponge and fibrin glue to promote new bone formation in rat calvarial bone defects, the latter being discreetly more advantageous. PMID:26814464

  13. 异种脱细胞真皮基质联合Bio-oss Collagen修复牙槽骨缺损的临床研究%Clinical application of acellular dermal matrix combined with Bio-oss Collagen to repair alveolar bone defects

    Institute of Scientific and Technical Information of China (English)

    杨春羚; 林良缘; 庄亮亮; 曾金表

    2011-01-01

    Objective: To investigate the effect of guided bone regeneration of acellular dermal matrix (ADM) combined with Bio -oss Collagen in alveolar defect. Method: 18 cases patients with severe alveolar bone resorption or damage were included.Bone defect after teeth extraction were very serious and the residual height and width of the alveolar bone were very limited in all these cases. Bio-oss Collagen was delivered into the sockets immediately after tooth extraction and covered with acellular dermal matrix membrane.Suture was removed 2 weeks postop.and the alveolar bone was regularly examined at the 3rd month. Result:New bone was found to form well in both physical examination and X-ray examination in all the 18 cases in the 3rd month.The height and width of the alveolar bone were significantly increased, providing a good bone condition for later FPD prosthetic treatment. Conclusion: Acellular dermal matrix combined with Bio-oss Collagen can improve the bone condition before restoration in clinical.%目的:通过引导骨再生(GBR)技术评估异种脱细胞真皮基质(acellular dermal matrix,ADM)与Bio-oss Collagen联合应用在修复牙槽骨缺损中的作用.方法:选择拔牙术后牙槽骨缺损严重的病例18例,拔牙同期在拔牙创植入Bio-oss Collagen并覆盖异种脱细胞真皮基质(海奥生物膜),术后2周拆线,3个月复诊并拍摄X线片.结果:术后经临床检查和X线检查,18例患者植骨区新骨形成良好,牙槽骨高度与丰满度明显改善,术区骨生成良好.结论:临床上异种脱细胞真皮基质与Bio-oss Collagen联合应用能有效修复牙槽骨缺损,改善修复前的骨条件.

  14. Enhancing amine terminals in an amine-deprived collagen matrix.

    LENUS (Irish Health Repository)

    Tiong, William H C

    2008-10-21

    Collagen, though widely used as a core biomaterial in many clinical applications, is often limited by its rapid degradability which prevents full exploitation of its potential in vivo. Polyamidoamine (PAMAM) dendrimer, a highly branched macromolecule, possesses versatile multiterminal amine surface groups that enable them to be tethered to collagen molecules and enhance their potential. In this study, we hypothesized that incorporation of PAMAM dendrimer in a collagen matrix through cross-linking will result in a durable, cross-linked collagen biomaterial with free -NH 2 groups available for further multi-biomolecular tethering. The aim of this study was to assess the physicochemical properties of a G1 PAMAM cross-linked collagen matrix and its cellular sustainability in vitro. Different amounts of G1 PAMAM dendrimer (5 or 10 mg) were integrated into bovine-derived collagen matrices through a cross-linking process, mediated by 5 or 25 mM 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) in 5 mM N-hydroxysuccinimide (NHS) and 50 mM 2-morpholinoethane sulfonic acid buffer at pH 5.5. The physicochemical properties of resultant matrices were investigated with scanning electron microscopy (SEM), collagenase degradation assay, differential scanning calorimetry (DSC), Fourier transform infrared (FTIR) spectra, and ninhydrin assay. Cellular sustainability of the matrices was assessed with Alamar Blue assay and SEM. There was no significant difference in cellular behavior between the treated and nontreated groups. However, the benefit of incorporating PAMAM in the cross-linking reaction was limited when higher concentrations of either agent were used. These results confirm the hypothesis that PAMAM dendrimer can be incorporated in the collagen cross-linking process in order to modulate the properties of the resulting cross-linked collagen biomaterial with free -NH 2 groups available for multi-biomolecular tethering.

  15. Bio-inspired in situ crosslinking and mineralization of electrospun collagen scaffolds for bone tissue engineering.

    Science.gov (United States)

    Dhand, Chetna; Ong, Seow Theng; Dwivedi, Neeraj; Diaz, Silvia Marrero; Venugopal, Jayarama Reddy; Navaneethan, Balchandar; Fazil, Mobashar H U T; Liu, Shouping; Seitz, Vera; Wintermantel, Erich; Beuerman, Roger W; Ramakrishna, Seeram; Verma, Navin K; Lakshminarayanan, Rajamani

    2016-10-01

    Bone disorders are the most common cause of severe long term pain and physical disability, and affect millions of people around the world. In the present study, we report bio-inspired preparation of bone-like composite structures by electrospinning of collagen containing catecholamines and Ca(2+). The presence of divalent cation induces simultaneous partial oxidative polymerization of catecholamines and crosslinking of collagen nanofibers, thus producing mats that are mechanically robust and confer photoluminescence properties. Subsequent mineralization of the mats by ammonium carbonate leads to complete oxidative polymerization of catecholamines and precipitation of amorphous CaCO3. The collagen composite scaffolds display outstanding mechanical properties with Young's modulus approaching the limits of cancellous bone. Biological studies demonstrate that human fetal osteoblasts seeded on to the composite scaffolds display enhanced cell adhesion, penetration, proliferation, differentiation and osteogenic expression of osteocalcin, osteopontin and bone matrix protein when compared to pristine collagen or tissue culture plates. Among the two catecholamines, mats containing norepinephrine displayed superior mechanical, photoluminescence and biological properties than mats loaded with dopamine. These smart multifunctional scaffolds could potentially be utilized to repair and regenerate bone defects and injuries. PMID:27475728

  16. Physical evidence for a glue holding mineralized collagen fibrils together in bone*

    Science.gov (United States)

    Hansma, P.

    2005-03-01

    Evidence from Atomic Force Microscope indentation, pulling and imaging, and macroscopic testing and enzymatic digestion, suggests that collagen fibrils and mineral plates are not the only components of bone with mechanical roles. A ``glue'' appears to bind mineralized collagen fibrils together. Order of magnitude calculations show that less than 1% by weight of this ``glue'' profoundly affects bone fracture resistance, as it involves a remarkable natural toughening and strengthening system: sacrificial bonds and hidden length. This system dissipates large amounts of work against entropic forces while stretching out the hidden length that is exposed when sacrificial bonds break. This appears to occur when mineralized collagen fibrils are torn apart or slid against each other during bone fracture. In bone, this system depends on multivalent positive ions such as calcium ions, which allows us to follow its influence up to macroscopic fracture testing levels. Many bone matrix proteoglycans and glycoproteins have negatively charged groups at physiological pHs that could be bound together into sacrificial bonds by multivalent positive ions, and are thus natural candidates for this ``glue.'' We cannot rule out a possible involvement of nonfibrillar collagen. Precisely which candidates are involved is yet to be determined. *NSF MRL DMR00-80034, NIH GM65354, NASA BiMAT URETI NCC-1-02037 (00000532), Veeco, USARL ARO DAAD19-03-D-0004

  17. Thermal stabilization of collagen in skin and decalcified bone

    Science.gov (United States)

    Miles, Christopher A.; Avery, Nicholas C.

    2011-04-01

    The state of collagen molecules in the fibres of tail tendon, skin and demineralized bone has been investigated in situ using differential scanning calorimetry (DSC). Hydroxyproline analysis and tissue digestion with bacterial collagenase and trypsin were used to confirm that the common cause of all the DSC endotherms was collagen denaturation. This occurred within a narrow temperature range in tendons, but over a wide temperature range in demineralized bone and old skin and demonstrated that in tendon and demineralized bone at least the same type I collagen molecule exists in different thermal states. Hypothesizing that this might be caused by different degrees of confinement within the fibre lattice, experiments were performed to measure the effect of changing the lattice dimensions by extracting the collagen into dilute solution with pepsin, swelling the lattice in acetic acid, and contracting the lattice by dehydration. A theoretical analysis was undertaken to predict the effect of dehydration. Results were consistent with the hypothesis, demonstrating that collagen molecules within the natural fibres of bone and old skin are located at different intermolecular spacings, revealing differences between molecules in the magnitude of either the attractive or repulsive forces controlling their separation. One potential cause of such variation is known differences in covalent cross-linking.

  18. The effects of bone marrow aspirate, bone graft, and collagen composites on fixation of titanium implants

    DEFF Research Database (Denmark)

    Babiker, Hassan; Ding, Ming; Sandri, Monica;

    2012-01-01

    contamination, and non union as well as the potential risk of disease transmission. Hydroxyapatite and collagen composites (HA/Collagen) have the potential in mimicking and replacing skeletal bones. This study attempted to determine the effects of newly developed HA/Collagen-composites with and without bone....../Collagen-BMA; autograft or allograft. Allograft was served as the control group. The observation period was 5 weeks. The sheep were euthanized and both femurs were harvested. A push-out mechanical test and histological analysis were performed. Results: No significant differences were seen in the mechanical properties...

  19. Rapid biomimetic mineralization of collagen fibrils and combining with human umbilical cord mesenchymal stem cells for bone defects healing.

    Science.gov (United States)

    Ye, Bihua; Luo, Xueshi; Li, Zhiwen; Zhuang, Caiping; Li, Lihua; Lu, Lu; Ding, Shan; Tian, Jinhuan; Zhou, Changren

    2016-11-01

    Collagen biomineralization is regulated by complicated interactions between the collagen matrix and non-collagenous extracellular proteins. Here, the use of sodium tripolyphosphate to simulate the templating functional motif of the C-terminal fragment of non-collagenous proteins is reported, and a low molecular weight polyacrylic acid served as a sequestration agent to stabilize amorphous calcium phosphate into nanoprecursors. Self-assembled collagen fibrils served as a fixed template for achieving rapid biomimetic mineralization in vitro. Results demonstrated that, during the mineralization process, intrafibrillar and extrafibrillar hydroxyapatite mineral with collagen fibrils formed and did so via bottom-up nanoparticle assembly based on the non-classical crystallization approach in the presence of these dual biomimetic functional analogues. In vitro human umbilical cord mesenchymal stem cell (hUCMSC) culture found that the mineralized scaffolds have a better cytocompatibility in terms of cell viability, adhesion, proliferation, and differentiation into osteoblasts. A rabbit femoral condyle defect model was established to confirm the ability of the n-HA/collagen scaffolds to facilitate bone regeneration and repair. The images of gross anatomy, MRI, CT and histomorphology taken 6 and 12weeks after surgery showed that the biomimetic mineralized collagen scaffolds with hUCMSCs can promote the healing speed of bone defects in vivo, and both of the scaffolds groups performing better than the bone defect control group. As new bone tissue formed, the scaffolds degraded and were gradually absorbed. All these results demonstrated that both of the scaffolds and cells have better histocompatibility. PMID:27523994

  20. Nanometeric hydroxyapatite in situ formed in demineralized bone matrix by electrochemical technique

    Institute of Scientific and Technical Information of China (English)

    CHEN Ji-da; WANG Yuan-ling; CAI Hao-xi; CAO Yin

    2001-01-01

    @@ To prepare biomimic bone materials, some thick meshes of demineralized bone matrix (DBM), which are the interest work of collagen fibrils, have been prepared in normal way, and calcium phosphate of nanometeric apatite-li.ke was introduced into these mesh works with aqueous calcium and phosphate salt solution by means of the electrochemical technique at room temperature.

  1. Immunomodulatory effects of amniotic membrane matrix incorporated into collagen scaffolds.

    Science.gov (United States)

    Hortensius, Rebecca A; Ebens, Jill H; Harley, Brendan A C

    2016-06-01

    Adult tendon wound repair is characterized by the formation of disorganized collagen matrix which leads to decreases in mechanical properties and scar formation. Studies have linked this scar formation to the inflammatory phase of wound healing. Instructive biomaterials designed for tendon regeneration are often designed to provide both structural and cellular support. In order to facilitate regeneration, success may be found by tempering the body's inflammatory response. This work combines collagen-glycosaminoglycan scaffolds, previously developed for tissue regeneration, with matrix materials (hyaluronic acid and amniotic membrane) that have been shown to promote healing and decreased scar formation in skin studies. The results presented show that scaffolds containing amniotic membrane matrix have significantly increased mechanical properties and that tendon cells within these scaffolds have increased metabolic activity even when the media is supplemented with the pro-inflammatory cytokine interleukin-1 beta. Collagen scaffolds containing hyaluronic acid or amniotic membrane also temper the expression of genes associated with the inflammatory response in normal tendon healing (TNF-α, COLI, MMP-3). These results suggest that alterations to scaffold composition, to include matrix known to decrease scar formation in vivo, can modify the inflammatory response in tenocytes. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 1332-1342, 2016.

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

    Science.gov (United States)

    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

  3. Does collagen trigger the recruitment of osteoblasts into vacated bone resorption lacunae during bone remodeling?

    DEFF Research Database (Denmark)

    Abdelgawad, Mohamed Essameldin; Søe, Kent; Andersen, Thomas Levin;

    2014-01-01

    and cell migration in various cell types, and whose inactivation is reported to lead to lack of bone formation and skeletal deformities. In the present study, an antibody directed against this receptor inhibits collagen internalization in osteoblast lineage cells and decreases to some extent...... recruitment potential are already known. Here we draw the attention on the osteoblast recruitment potential of the collagen that is freshly demineralized by the osteoclast. Our evidence is based on observations on adult human cancellous bone, combined with in vitro assays. First, freshly eroded surfaces where...... osteoblasts have to be recruited show the presence of non-degraded demineralized collagen and close cell-collagen interactions, as revealed by electron microscopy, while surface-bound collagen strongly attracts osteoblast lineage cells in a transmembrane migration assay. Compared with other extracellular...

  4. Collagen osteoid-like model allows kinetic gene expression studies of non-collagenous proteins in relation with mineral development to understand bone biomineralization.

    Science.gov (United States)

    Silvent, Jérémie; Nassif, Nadine; Helary, Christophe; Azaïs, Thierry; Sire, Jean-Yves; Guille, Marie Madeleine Giraud

    2013-01-01

    Among persisting questions on bone calcification, a major one is the link between protein expression and mineral deposition. A cell culture system is here proposed opening new integrative studies on biomineralization, improving our knowledge on the role played by non-collagenous proteins in bone. This experimental in vitro model consisted in human primary osteoblasts cultured for 60 days at the surface of a 3D collagen scaffold mimicking an osteoid matrix. Various techniques were used to analyze the results at the cellular and molecular level (adhesion and viability tests, histology and electron microscopy, RT- and qPCR) and to characterize the mineral phase (histological staining, EDX, ATG, SAED and RMN). On long term cultures human bone cells seeded on the osteoid-like matrix displayed a clear osteoblast phenotype as revealed by the osteoblast-like morphology, expression of specific protein such as alkaline phosphatase and expression of eight genes classically considered as osteoblast markers, including BGLAP, COL1A1, and BMP2. Von Kossa and alizarine red allowed us to identify divalent calcium ions at the surface of the matrix, EDX revealed the correct Ca/P ratio, and SAED showed the apatite crystal diffraction pattern. In addition RMN led to the conclusion that contaminant phases were absent and that the hydration state of the mineral was similar to fresh bone. A temporal correlation was established between quantified gene expression of DMP1 and IBSP, and the presence of hydroxyapatite, confirming the contribution of these proteins to the mineralization process. In parallel a difference was observed in the expression pattern of SPP1 and BGLAP, which questioned their attributed role in the literature. The present model opens new experimental possibilities to study spatio-temporal relations between bone cells, dense collagen scaffolds, NCPs and hydroxyapatite mineral deposition. It also emphasizes the importance of high collagen density environment in bone cell

  5. Greener synthesis of electrospun collagen/hydroxyapatite composite fibers with an excellent microstructure for bone tissue engineering.

    Science.gov (United States)

    Zhou, Yuanyuan; Yao, Hongchang; Wang, Jianshe; Wang, Dalu; Liu, Qian; Li, Zhongjun

    2015-01-01

    In bone tissue engineering, collagen/hydroxyapatite (HAP) fibrous composite obtained via electrospinning method has been demonstrated to support the cells' adhesion and bone regeneration. However, electrospinning of natural collagen often requires the use of cytotoxic organic solvents, and the HAP crystals were usually aggregated and randomly distributed within a fibrous matrix of collagen, limiting their clinical potential. Here, an effective and greener method for the preparation of collagen/HAP composite fibers was developed for the first time, and this green product not only had 40 times higher mechanical properties than that previously reported, but also had an excellent microstructure similar to that of natural bone. By dissolving type I collagen in environmentally friendly phosphate buffered saline/ethanol solution instead of the frequently-used cytotoxic organic solvents, followed with the key step of desalination, co-electrospinning the collagen solution with the HAP sol, generates a collagen/HAP composite with a uniform and continuous fibrous morphology. Interestingly, the nano-HAP needles were found to preferentially orient along the longitudinal direction of the collagen fibers, which mimicked the nanostructure of natural bones. Based on the characterization of the related products, the formation mechanism for this novel phenomenon was proposed. After cross-linking with 1-ethyl-3-(3-dimethyl-aminopropyl)-1-carbodiimide hydrochloride/N-hydroxysuccinimide, the obtained composite exhibited a significant enhancement in mechanical properties. In addition, the biocompatibility of the obtained composite fibers was evaluated by in vitro culture of the human myeloma cells (U2-OS). Taken together, the process outlined herein provides an effective, non-toxic approach for the fabrication of collagen/HAP composite nanofibers that could be good candidates for bone tissue engineering. PMID:25995630

  6. Enhancement of tendon–bone healing via the combination of biodegradable collagen-loaded nanofibrous membranes and a three-dimensional printed bone-anchoring bolt

    Science.gov (United States)

    Chou, Ying-Chao; Yeh, Wen-Lin; Chao, Chien-Lin; Hsu, Yung-Heng; Yu, Yi-Hsun; Chen, Jan-Kan; Liu, Shih-Jung

    2016-01-01

    A composite biodegradable polymeric model was developed to enhance tendon graft healing. This model included a biodegradable polylactide (PLA) bolt as the bone anchor and a poly(D,L-lactide-co-glycolide) (PLGA) nanofibrous membrane embedded with collagen as a biomimic patch to promote tendon–bone interface integration. Degradation rate and compressive strength of the PLA bolt were measured after immersion in a buffer solution for 3 months. In vitro biochemical characteristics and the nanofibrous matrix were assessed using a water contact angle analyzer, pH meter, and tetrazolium reduction assay. In vivo efficacies of PLGA/collagen nanofibers and PLA bolts for tendon–bone healing were investigated on a rabbit bone tunnel model with histological and tendon pullout tests. The PLGA/collagen-blended nanofibrous membrane was a hydrophilic, stable, and biocompatible scaffold. The PLA bolt was durable for tendon–bone anchoring. Histology showed adequate biocompatibility of the PLA bolt on a medial cortex with progressive bone ingrowth and without tissue overreaction. PLGA nanofibers within the bone tunnel also decreased the tunnel enlargement phenomenon and enhanced tendon–bone integration. Composite polymers of the PLA bolt and PLGA/collagen nanofibrous membrane can effectively promote outcomes of tendon reconstruction in a rabbit model. The composite biodegradable polymeric system may be useful in humans for tendon reconstruction. PMID:27601901

  7. Enhancement of tendon-bone healing via the combination of biodegradable collagen-loaded nanofibrous membranes and a three-dimensional printed bone-anchoring bolt.

    Science.gov (United States)

    Chou, Ying-Chao; Yeh, Wen-Lin; Chao, Chien-Lin; Hsu, Yung-Heng; Yu, Yi-Hsun; Chen, Jan-Kan; Liu, Shih-Jung

    2016-01-01

    A composite biodegradable polymeric model was developed to enhance tendon graft healing. This model included a biodegradable polylactide (PLA) bolt as the bone anchor and a poly(D,L-lactide-co-glycolide) (PLGA) nanofibrous membrane embedded with collagen as a biomimic patch to promote tendon-bone interface integration. Degradation rate and compressive strength of the PLA bolt were measured after immersion in a buffer solution for 3 months. In vitro biochemical characteristics and the nanofibrous matrix were assessed using a water contact angle analyzer, pH meter, and tetrazolium reduction assay. In vivo efficacies of PLGA/collagen nanofibers and PLA bolts for tendon-bone healing were investigated on a rabbit bone tunnel model with histological and tendon pullout tests. The PLGA/collagen-blended nanofibrous membrane was a hydrophilic, stable, and biocompatible scaffold. The PLA bolt was durable for tendon-bone anchoring. Histology showed adequate biocompatibility of the PLA bolt on a medial cortex with progressive bone ingrowth and without tissue overreaction. PLGA nanofibers within the bone tunnel also decreased the tunnel enlargement phenomenon and enhanced tendon-bone integration. Composite polymers of the PLA bolt and PLGA/collagen nanofibrous membrane can effectively promote outcomes of tendon reconstruction in a rabbit model. The composite biodegradable polymeric system may be useful in humans for tendon reconstruction. PMID:27601901

  8. A comparative study of fibrous dysplasia and osteofibrous dysplasia with regard to expressions of c-fos and c-jun products and bone matrix proteins: a clinicopathologic review and immunohistochemical study of c-fos, c-jun, type I collagen, osteonectin, osteopontin, and osteocalcin.

    Science.gov (United States)

    Sakamoto, A; Oda, Y; Iwamoto, Y; Tsuneyoshi, M

    1999-12-01

    Fibrous dysplasia and osteofibrous dysplasia are both benign fibro-osseous lesions of the bone and are generally seen during childhood or adolescence. Histologically, the features of these bone lesions sometimes look quite similar, but their precise nature remains controversial. We retrospectively studied clinicopathologic findings in 62 cases of fibrous dysplasia and 20 cases of osteofibrous dysplasia with regard to their anatomic location and histological appearance. From among these cases, the immunohistochemical expressions of c-fos and c-jun proto-oncogene products and bone matrix proteins of type I collagen, osteonectin, osteopontin, and osteocalcin were evaluated in 20 typical fibrous dysplasias and 17 osteofibrous dysplasias using paraffin sections, and these expressions were then assessed semiquantitatively. Microscopically, fibrous dysplasia showed various secondary changes, such as hyalinization, hemorrhage, xanthomatous reaction, and cystic change in 22 of the 62 cases (35%). This was a higher incidence than in osteofibrous dysplasia, in which only 2 of the 20 cases (10%) showed such changes. In the elderly fibrous dysplasia cases, the cellularity of fibroblast-like cells was rather low, and those cases were hyalinized. Almost all of the cases of fibrous dysplasia and osteofibrous dysplasia showed positive expressions of c-fos and c-jun products. The expressions of type I collagen and osteopontin showed no difference between fibrous dysplasia and osteofibrous dysplasia. Immunoreactivity for osteonectin in bone matrix was detected in only 1 case of fibrous dysplasia (1 of 20), whereas it was recognized in 14 of the 17 cases of osteofibrous dysplasia. Furthermore, the immunoreactivity for osteocalcin in bone matrix and fibroblast-like cells was higher in fibrous dysplasia than it was in osteofibrous dysplasia, semiquantitatively. Our immunohistochemical results regarding osteonectin and osteocalcin suggest that the bone matrix of fibrous dysplasia is

  9. On the role of type IX collagen in the extracellular matrix of cartilage: type IX collagen is localized to intersections of collagen fibrils

    OpenAIRE

    1986-01-01

    The tissue distribution of type II and type IX collagen in 17-d-old chicken embryo was studied by immunofluorescence using polyclonal antibodies against type II collagen and a peptic fragment of type IX collagen (HMW), respectively. Both proteins were found only in cartilage where they were co-distributed. They occurred uniformly throughout the extracellular matrix, i.e., without distinction between pericellular, territorial, and interterritorial matrices. Tissues that undergo endochondral bo...

  10. Altered distributions of bone tissue mineral and collagen properties in women with fragility fractures.

    Science.gov (United States)

    Wang, Zhen Xiang; Lloyd, Ashley A; Burket, Jayme C; Gourion-Arsiquaud, Samuel; Donnelly, Eve

    2016-03-01

    Heterogeneity of bone tissue properties is emerging as a potential indicator of altered bone quality in pathologic tissue. The objective of this study was to compare the distributions of tissue properties in women with and without histories of fragility fractures using Fourier transform infrared (FTIR) imaging. We extended a prior study that examined the relationship of the mean FTIR properties to fracture risk by analyzing in detail the widths and the tails of the distributions of FTIR properties in biopsies from fracture and non-fracture cohorts. The mineral and matrix properties of cortical and trabecular iliac crest tissue were compared in biopsies from women with a history of fragility fracture (+Fx; n=21, age: mean 54±SD 15y) and with no history of fragility fracture (-Fx; n=12, age: 57±5y). A subset of the patients included in the -Fx group were taking estrogen-plus-progestin hormone replacement therapy (HRT) (-Fx+HRT n=8, age: 58±5y) and were analyzed separately from patients with no history of HRT (-Fx-HRT n=4, age: 56±7y). When the FTIR parameter mean values were examined by treatment group, the trabecular tissue of -Fx-HRT patients had a lower mineral:matrix ratio (M:M) and collagen maturity (XLR) than that of -Fx+HRT patients (-22% M:M, -18% XLR) and +Fx patients (-17% M:M, -18% XLR). Across multiple FTIR parameters, tissue from the -Fx-HRT group had smaller low-tail (5th percentile) values than that from the -Fx+HRT or +Fx groups. In trabecular collagen maturity and crystallinity (XST), the -Fx-HRT group had smaller low-tail values than those in the -Fx+HRT group (-16% XLR, -5% XST) and the +Fx group (-17% XLR, -7% XST). The relatively low values of trabecular mineral:matrix ratio and collagen maturity and smaller low-tail values of collagen maturity and crystallinity observed in the -Fx-HRT group are characteristic of younger tissue. Taken together, our data suggest that the presence of newly formed tissue that includes small/imperfect crystals

  11. Collagens

    OpenAIRE

    Gordon, Marion K.; Hahn, Rita A.

    2009-01-01

    The collagens represent a family of trimeric extracellular matrix molecules used by cells for structural integrity and other functions. The three α chains that form the triple helical part of the molecule are composed of repeating peptide triplets of glycine-X-Y. X and Y can be any amino acid but are often proline and hydroxyproline, respectively. Flanking the triple helical regions (i.e., Col domains) are non-glycine-X-Y regions, termed non-collagenous domains. These frequently contain recog...

  12. Enhancement of tendon–bone healing via the combination of biodegradable collagen-loaded nanofibrous membranes and a three-dimensional printed bone-anchoring bolt

    Directory of Open Access Journals (Sweden)

    Chou YC

    2016-08-01

    Full Text Available Ying-Chao Chou,1,2 Wen-Lin Yeh,2 Chien-Lin Chao,1 Yung-Heng Hsu,1,2 Yi-Hsun Yu,1,2 Jan-Kan Chen,3 Shih-Jung Liu1,2 1Department of Mechanical Engineering, Chang Gung University, 2Department of Orthopedic Surgery, Chang Gung Memorial Hospital, 3Department of Physiology and Pharmacology, Chang Gung University, Taoyuan, Taiwan Abstract: A composite biodegradable polymeric model was developed to enhance tendon graft healing. This model included a biodegradable polylactide (PLA bolt as the bone anchor and a poly(D,L-lactide-co-glycolide (PLGA nanofibrous membrane embedded with collagen as a biomimic patch to promote tendon–bone interface integration. Degradation rate and compressive strength of the PLA bolt were measured after immersion in a buffer solution for 3 months. In vitro biochemical characteristics and the nanofibrous matrix were assessed using a water contact angle analyzer, pH meter, and tetrazolium reduction assay. In vivo efficacies of PLGA/collagen nanofibers and PLA bolts for tendon–bone healing were investigated on a rabbit bone tunnel model with histological and tendon pullout tests. The PLGA/collagen-blended nanofibrous membrane was a hydrophilic, stable, and biocompatible scaffold. The PLA bolt was durable for tendon–bone anchoring. Histology showed adequate biocompatibility of the PLA bolt on a medial cortex with progressive bone ingrowth and without tissue overreaction. PLGA nanofibers within the bone tunnel also decreased the tunnel enlargement phenomenon and enhanced tendon–bone integration. Composite polymers of the PLA bolt and PLGA/collagen nanofibrous membrane can effectively promote outcomes of tendon reconstruction in a rabbit model. The composite biodegradable polymeric system may be useful in humans for tendon reconstruction. Keywords: polylactide–polyglycolide nanofibers, PLGA, collagen, 3D printing, polylactide, PLA, bone-anchoring bolts, tendon healing

  13. Effect of Simvastatin collagen graft on wound healing of defective bone

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Jun Ho; Kim, Gyu Tae [Department of Oral and Maxillofacial Radiology, School of Dentistry, Kyung Hee University, Seoul (Korea, Republic of); Choi, Yong Suk; Lee, Hyeon Woo; Hwang, Eui Hwan [Institute of Oral Biology, School of Dentistry, Kyung Hee University, Seoul (Korea, Republic of)

    2008-09-15

    To observe and evaluate the effects of Simvastatin-induced osteogenesis on the wound healing of defective bone. 64 defective bones were created in the parietal bone of 32 New Zealand White rabbits. The defects were grafted with collagen matrix carriers mixed with Simvastatin solution in the experimental group of 16 rabbits and with collagen matrix carriers mixed with water in the controlled group. The rabbits were terminated at an interval of 3, 5, 7, and 9 days, 2, 4, 6, and 8 weeks after the formation of defective bone. The wound healing was evaluated by soft X-ray radiography. The tissues within defective bones were evaluated through the analysis of flow cytometry for the manifestation of Runx2 and Osteocalcin, and observed histopathologically by using H-E stain and Masson's trichrome stain. Results : 1. In the experimental group, flow cytometry revealed more manifestation of Runx2 at 5, 7, and 9 days and Osteocalcin at 2 weeks than in the controlled groups, but there was few difference in comparison with the controlled group. 2. In the experimental group, flow cytometry revealed considerably more cells and erythrocytes at 5, 7, and 9 days in comparison with the controlled group. 3. In the experimental group, soft x-ray radiography revealed the extended formation of trabeculation at 2, 4, 6, and 8 weeks. 4. Histopathological features of the experimental group showed more fibroblasts and newly formed vessels at 5 and 7 days, and the formation of osteoid tissues at 9 days, and the newly formed trabeculations at 4 and 6 weeks. As the induced osteogenesis by Simvastatin, there was few contrast of the manifestation between Runx2 and Osteocalcin based on the differentiation of osteoblasts. But it was considered that the more formation of cells and erythrocytes depending on newly formed vessels in the experimental group obviously had an effect on the bone regeneration.

  14. Nanoporous Structure of Bone Matrix at Osteoporosis from Data of Atomic Force Microscopy and IR Spectroscopy

    Directory of Open Access Journals (Sweden)

    A. A. Gaidash

    2011-01-01

    Full Text Available It was found that in an osteoporotic bone the fraction of nanosized pores decreases, the mineral phase amorphizes, hydrated shells around mineralized particles of the bone matrix thicken, and adhesion forces increase. This contributes to the formation of water clusters similar to bulk water clusters compared to the healthy bone tissue and leads to the accumulation of more viscous liquid with increased intermolecular interaction forces in the pores of the bone matrix. Given this, the rates of chemical reactions proceeding in the water phase of ultrathin channels of general parts of collagen fibrils decrease. Ultimately, nanopores of collagen-apatite interfaces lose, to a certain extent, the capability of catalyzing the hydroxyapatite crystallization.

  15. Long-range movement and fibril association of type X collagen within embryonic cartilage matrix.

    OpenAIRE

    Chen, Q A; Gibney, E; Fitch, J M; Linsenmayer, C; Schmid, T.M.; Linsenmayer, T F

    1990-01-01

    A recent immunoelectron microscopic study of type X collagen in developing cartilage gave results that could be explained by movement of the molecule from one region of the cartilage matrix to another, there becoming associated with preexisting collagen fibrils. In the present study, to test the feasibility of this model we incubated pieces of nonhypertrophic, embryonic chicken sternal cartilage (which has no endogenous type X collagen) in medium with type X collagen and then used immunofluor...

  16. Angiogenic Type I Collagen Extracellular Matrix Integrated with Recombinant Bacteriophages Displaying Vascular Endothelial Growth Factors.

    Science.gov (United States)

    Yoon, Junghyo; Korkmaz Zirpel, Nuriye; Park, Hyun-Ji; Han, Sewoon; Hwang, Kyung Hoon; Shin, Jisoo; Cho, Seung-Woo; Nam, Chang-Hoon; Chung, Seok

    2016-01-21

    Here, a growth-factor-integrated natural extracellular matrix of type I collagen is presented that induces angiogenesis. The developed matrix adapts type I collagen nanofibers integrated with synthetic colloidal particles of recombinant bacteriophages that display vascular endothelial growth factor (VEGF). The integration is achieved during or after gelation of the type I collagen and the matrix enables spatial delivery of VEGF into a desired region. Endothelial cells that contact the VEGF are found to invade into the matrix to form tube-like structures both in vitro and in vivo, proving the angiogenic potential of the matrix.

  17. Collagen in the spicule organic matrix of the gorgonian Leptogorgia virgulata

    Science.gov (United States)

    Kingsley, R. J.; Tsuzaki, M.; Watabe, N.; Mechanic, G. L.

    1990-01-01

    Decalcification of the calcareous spicules from the gorgonian Leptogorgia virgulata reveals an organic matrix that may be divided into water insoluble and soluble fractions. The insoluble fraction displays characteristics typical of collagen, which is an unusual component of an invertebrate calcium carbonate structure. This matrix fraction exhibits a collagenous amino acid profile and behavior upon SDS-PAGE. Furthermore, the reducible crosslink, dihydroxylysinonorleucine (DHLNL), is detected in this fraction. The composition of the matrix varies seasonally; i.e., the collagenous composition is most prevalent in the summer. These results indicate that the insoluble matrix is a dynamic structure. Potential roles of this matrix in spicule calcification are discussed.

  18. [Osteoplastic effectiveness of mineralized bone matrix].

    Science.gov (United States)

    2013-01-01

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

  19. Combined role of type IX collagen and cartilage oligomeric matrix protein in cartilage matrix assembly: Cartilage oligomeric matrix protein counteracts type IX collagen-induced limitation of cartilage collagen fibril growth in mouse chondrocyte cultures

    NARCIS (Netherlands)

    Blumbach, K.; Bastiaansen-Jenniskens, Y.M.; Groot, J. de; Paulsson, M.; Osch, G.J.V.M. van; Zaucke, F.

    2009-01-01

    Objective. Defects in the assembly and composition of cartilage extracellular matrix are likely to result in impaired matrix integrity and increased susceptibility to cartilage degeneration. The aim of this study was to determine the functional interaction of the collagen fibril-associated proteins

  20. In Vitro Mineralization of an Osteoid-Like Dense Collagen Construct for Bone Tissue Engineering

    Science.gov (United States)

    Marelli, Benedetto

    The aim of this doctoral research was to design and evaluate strategies to rapidly achieve an acellular mineralization of an osteoid-like dense collagen gel for potential applications in bone regeneration. It was hypothesized that the collagen fibrillar density (CFD) affects the microenvironment and the physical properties of the framework of collagen gels. To test this hypothesis, and as a first objective, the mineralization of collagen gel sheets, rolls and strips with increasing CFDs was investigated in vitro in simulated body fluid (SBF). Collagen gels with physiologically relevant CFDs (14.1 wt%) led to greater extent of mineralization (12 dry wt% at day 14 in SBF), when compared to highly hydrated gels. Chemical characterization confirmed this mineral phase to be CHA, which significantly increased the gel apparent modulus and ultimate tensile strength (UTS). Surprisingly, CFD also affected the electrostatic properties of collagen gel, as investigated by quantifying the extent of anionic and cationic dyes bound to collagen gels with different CFDs. It was therefore proposed that the increase in gel CFD led to a more physiological microenvironment, resulting in a higher number of fibril-to-fibril contact points and an increase in charge concentration, which facilitated the mineral formation and validated the proposed osteoid model. As a second objective, the mineralization of dense collagen (DC) gels with physiologically relevant CFD (14.1 wt%) was enhanced and accelerated by mimicking the role of anionic non collagenous proteins (NCPs) in the native osteoid, which act as CHA nucleators. Two strategies were implemented: first, the influence of collagen fibrillization pH on the extent of DC gel mineralization was investigated. Since the collagen molecule is slightly positively charged at physiological pH (isoelectric point at pH 7.8), it was hypothesized that it would be more negatively charged if formed in an alkaline environment, i.e., above its isoelectric

  1. Repair of rabbit radial bone defects using true bone ceramics combined with BMP-2-related peptide and type I collagen

    International Nuclear Information System (INIS)

    An ideal bone graft material is the one characterized with good biocompatibility, biodegradation, osteoconductivity and osteoinductivity. In this study, a novel synthetic BMP-2-related peptide (designated P24) corresponding to residues of the knuckle epitope of BMP-2 was introduced into a biomimetic scaffold based on sintered bovine bone or true bone ceramics (TBC) and type I collagen (TBC/collagen I) using a simulated body fluid (SBF). Hydroxylapatite crystal mineralization with a Ca/P molar ratio of 1.63 was observed on the surface of P24/TBC/collagen I composite by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX) and X-ray diffraction (XRD) techniques. Cell adhesion rate evaluation of bone marrow stromal cells (BMSCs) seeded on materials in vitro showed that the percentage of cells attached to P24/TBC/collagen I composite was significantly higher than that of the TBC/collagen I composite. A 10 mm unilateral segmental bone defect was created in the radius of New Zealand white rabbits and randomly implanted with three groups of biomaterials (Group A: P24/TBC/collagen I composite; Group B: TBC/collagen I composite and Group C: TBC alone). Based on radiographic evaluation and histological examination, the implants of P24/TBC/collagen I composite significantly stimulated bone growth, thereby confirming the enhanced rate of bone healing compared with that of TBC/collagen I composite and TBC alone. It was concluded that BMP-2-related peptide P24 could induce nucleation of calcium phosphate crystals on the surface of TBC/collagen I composite. The TBC/collagen I composite loaded with the synthetic BMP-2-related peptide is a promising scaffold biomaterial for bone tissue engineering.

  2. Biomimetically Enhanced Demineralized Bone Matrix for Bone Regenerative Applications

    Directory of Open Access Journals (Sweden)

    Sriram eRavindran

    2015-10-01

    Full Text Available 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.

  3. Targeting a novel bone degradation pathway in primary bone cancer by inactivation of the collagen receptor uPARAP/Endo180

    DEFF Research Database (Denmark)

    Engelholm, Lars H; Melander, Maria C; Hald, Andreas;

    2016-01-01

    In osteosarcoma, a primary mesenchymal bone cancer occurring predominantly in younger patients, invasive tumour growth leads to extensive bone destruction. This process is insufficiently understood, cannot be efficiently counteracted and calls for novel means of treatment. The endocytic collagen...... of degrading the protein component of surface-labelled bone slices in a process dependent on MMP activity and uPARAP/Endo180. Systemic treatment of the sarcoma-inoculated mice with a mouse monoclonal antibody that blocks murine uPARAP/Endo180 led to a strong reduction of bone destruction. Our findings identify...... receptor, uPARAP/Endo180, is expressed on various mesenchymal cell types and is involved in bone matrix turnover during normal bone growth. Human osteosarcoma specimens showed strong expression of this receptor on tumour cells, along with the collagenolytic metalloprotease, MT1-MMP. In advanced tumours...

  4. Abnormal bone collagen morphology and decreased bone strength in growth hormone-deficient rats

    DEFF Research Database (Denmark)

    Lange, Martin; Qvortrup, Klaus; Svendsen, Ole Lander;

    2004-01-01

    rats as compared to their controls (P rats with isolated GHD. Whether similar conditions are present in GHD patients need further investigations. The changes described, however, may provide...... collagen morphology and bone mineralisation in cortical bone as well as bone strength in GHD rats to try to clarify the explanation for the increased fracture rate. The Dw-4 rat was used as a model for GHD. This strain of rats has an autosomal recessive disorder, reducing GH synthesis to approximately 10......% and growth rate to approximately 40-50% when compared to normal control rats. Five male Dw-4 rats were examined at age 12 weeks and five healthy Lewis rats served as age-matched controls. The animals were examined for (1) bone mineral status by dual energy X-ray absorptometry (DXA) and ash weight/bone volume...

  5. Greener synthesis of electrospun collagen/hydroxyapatite composite fibers with an excellent microstructure for bone tissue engineering

    Directory of Open Access Journals (Sweden)

    Zhou YY

    2015-04-01

    Full Text Available Yuanyuan Zhou,1,2 Hongchang Yao,1 Jianshe Wang,1 Dalu Wang,1 Qian Liu,1 Zhongjun Li11College of Chemistry and Molecular Engineering, Zhengzhou University, Zhengzhou, People’s Republic of China; 2Institute of Enviromental and Municipal Engineering, North China University of Water Resources and Electric Power, Zhengzhou, People’s Republic of ChinaAbstract: In bone tissue engineering, collagen/hydroxyapatite (HAP fibrous composite obtained via electrospinning method has been demonstrated to support the cells’ adhesion and bone regeneration. However, electrospinning of natural collagen often requires the use of cytotoxic organic solvents, and the HAP crystals were usually aggregated and randomly distributed within a fibrous matrix of collagen, limiting their clinical potential. Here, an effective and greener method for the preparation of collagen/HAP composite fibers was developed for the first time, and this green product not only had 40 times higher mechanical properties than that previously reported, but also had an excellent microstructure similar to that of natural bone. By dissolving type I collagen in environmentally friendly phosphate buffered saline/ethanol solution instead of the frequently-used cytotoxic organic solvents, followed with the key step of desalination, co-electrospinning the collagen solution with the HAP sol, generates a collagen/HAP composite with a uniform and continuous fibrous morphology. Interestingly, the nano-HAP needles were found to preferentially orient along the longitudinal direction of the collagen fibers, which mimicked the nanostructure of natural bones. Based on the characterization of the related products, the formation mechanism for this novel phenomenon was proposed. After cross-linking with 1-ethyl-3-(3-dimethyl-aminopropyl-1-carbodiimide hydrochloride/N-hydroxysuccinimide, the obtained composite exhibited a significant enhancement in mechanical properties. In addition, the biocompatibility of the

  6. Treatment with eldecalcitol positively affects mineralization, microdamage, and collagen crosslinks in primate bone.

    Science.gov (United States)

    Saito, Mitsuru; Grynpas, Marc D; Burr, David B; Allen, Matthew R; Smith, Susan Y; Doyle, Nancy; Amizuka, Norio; Hasegawa, Tomoka; Kida, Yoshikuni; Marumo, Keishi; Saito, Hitoshi

    2015-04-01

    Eldecalcitol (ELD), an active form of vitamin D analog approved for the treatment of osteoporosis in Japan, increases lumbar spine bone mineral density (BMD), suppresses bone turnover markers, and reduces fracture risk in patients with osteoporosis. We have previously reported that treatment with ELD for 6 months improved the mechanical properties of the lumbar spine in ovariectomized (OVX) cynomolgus monkeys. ELD treatment increased lumbar BMD, suppressed bone turnover markers, and reduced histomorphometric parameters of both bone formation and resorption in vertebral trabecular bone. In this study, we elucidated the effects of ELD on bone quality (namely, mineralization, microarchitecture, microdamage, and bone collagen crosslinks) in OVX cynomolgus monkeys in comparison with OVX-vehicle control monkeys. Density fractionation of bone powder prepared from lumbar vertebrae revealed that ELD treatment shifted the distribution profile of bone mineralization to a higher density, and backscattered electron microscopic imaging showed improved trabecular bone connectivity in the ELD-treated groups. Higher doses of ELD more significantly reduced the amount of microdamage compared to OVX-vehicle controls. The fractionated bone powder samples were divided according to their density, and analyzed for collagen crosslinks. Enzymatic crosslinks were higher in both the high-density (≥2.0 mg/mL) and low-density (mineralization, but prevented non-enzymatic reaction of collagen crosslinks and accumulation of bone microdamage. Bone anti-resorptive agents such as bisphosphonates slow down bone remodeling so that bone mineralization, bone microdamage, and non-enzymatic collagen crosslinks all increase. Bone anabolic agents such as parathyroid hormone decrease bone mineralization and bone microdamage by stimulating bone remodeling. ELD did not fit into either category. Histological analysis indicated that the ELD treatment strongly suppressed bone resorption by reducing the number of

  7. Peri-implant soft tissue augmentation with a porcine collagen matrix.

    Directory of Open Access Journals (Sweden)

    Yuri Castro

    2014-12-01

    Full Text Available Resumen: Una buena cantidad y grosor de tejido queratinizado alrededor de implantes ha sido asociado con una mejor salud periimplantaria, menos pérdida ósea y una mejora en la estética. El propósito de este caso clínico fue evaluar un nuevo xenoinjerto de origen porcino (matriz de colágeno al ser utilizada como un injerto interposicional para aumentar el grosor de la mucosa periimplantaria. Son pocos los estudios que utilizan la matriz de colágeno como sustituto del injerto conectivo subepitelial alrededor de implantes. El caso clínico incluyó un implante a nivel de la pieza 15, en el cual durante la colocación del pilar de cicatrización se aprovechó para engrosar la mucosa periimplantaria utilizando una matriz de colágeno. Se obtuvo un aumento de grosor de 1,5mm manteniéndose la cantidad de mucosa queratinizada de 4mm. Se concluyó que la matriz de colágeno de origen porcino es una buena alternativa para aumentar el grosor de la mucosa periimplantaria, además de reducir la morbilidad, ser de fácil manejo y de fácil sutura. Abstract: A good amount and width of keratinized tissue around implants has been associated with better health periimplant, less bone loss and improved aesthetics. The purpose of this case was to evaluate a new porcine xenograft (collagen matrix when used as an interpositional graft to increase the thickness of the peri-implant mucosa. Few studies using the collagen matrix as a substitute for subepithelial connective graft around implants are. The case involved an implant clinical at level of teeth 15 during placement of scar took the opportunity to swell the peri-implant mucosa with the collagen matrix. An increase in thickness of 1.5 mm while maintaining the amount of keratinized mucosa 4mm was obtained. We conclude that the collagen matrix of porcine origin is a good alternative to increase the thickness of the peri-implant mucosa and reduce morbidity, be easy to handle and easy to suture.

  8. Comparison of whole calvarial bones and long bones during early growth in rats. Histology and collagen composition.

    Science.gov (United States)

    Zika, J M; Klein, L

    1975-07-25

    The distribution of ossified collagen (bone) and uncalcified collagen (fibrous tissue and cartilage) was compared histologically for rat and dog calvaria at birth. The relative amount of bone and uncalcified collagen was quantitated morphologically for rat calvaria during the first four weeks of rapid growth. Whereas dog calvaria are essentially ossified at birth, rat calvaria at birth consist mostly of fibrous tissue but rapidly become ossified with growth. Bacterial collagenase was used to separate uncalcified collagen from calcified collagen of whole membranous bones (frontal and parietal) and long bones (femur and humerus) at birth from man, monkey, dog, guinea pig, rabbit and rat. By this means quantitative changes in the relative fractions of the two forms of collagen were determined during the first eight weeks of postnatal growth for each type of rat bone. Quantitative biochemical data on whole rat bones (calvarium, femur, humerus) confirmed measurements based on histology which showed that at birth rat calvaria are mostly uncalcified as compared to other species whose bones are mostly ossified at birth. With growth rat membranous bones ossify more rapidly than long bones.

  9. Chitosan-collagen porous scaffold and bone marrow mesenchymal stem cell transplantation for ischemic stroke

    OpenAIRE

    Feng Yan; Wei Yue; Yue-lin Zhang; Guo-chao Mao; Ke Gao; Zhen-xing Zuo; Ya-jing Zhang; Hui Lu

    2015-01-01

    In this study, we successfully constructed a composite of bone marrow mesenchymal stem cells and a chitosan-collagen scaffold in vitro, transplanted either the composite or bone marrow mesenchymal stem cells alone into the ischemic area in animal models, and compared their effects. At 14 days after co-transplantation of bone marrow mesenchymal stem cells and the hitosan-collagen scaffold, neurological function recovered noticeably. Vascular endothelial growth factor expression and nestin-labe...

  10. Evaluation of multi-scale mineralized collagen-polycaprolactone composites for bone tissue engineering.

    Science.gov (United States)

    Weisgerber, D W; Erning, K; Flanagan, C L; Hollister, S J; Harley, B A C

    2016-08-01

    A particular challenge in biomaterial development for treating orthopedic injuries stems from the need to balance bioactive design criteria with the mechanical and geometric constraints governed by the physiological wound environment. Such trade-offs are of particular importance in large craniofacial bone defects which arise from both acute trauma and chronic conditions. Ongoing efforts in our laboratory have demonstrated a mineralized collagen biomaterial that can promote human mesenchymal stem cell osteogenesis in the absence of osteogenic media but that possesses suboptimal mechanical properties in regards to use in loaded wound sites. Here we demonstrate a multi-scale composite consisting of a highly bioactive mineralized collagen-glycosaminoglycan scaffold with micron-scale porosity and a polycaprolactone support frame (PCL) with millimeter-scale porosity. Fabrication of the composite was performed by impregnating the PCL support frame with the mineral scaffold precursor suspension prior to lyophilization. Here we evaluate the mechanical properties, permeability, and bioactivity of the resulting composite. Results indicated that the PCL support frame dominates the bulk mechanical response of the composite resulting in a 6000-fold increase in modulus compared to the mineral scaffold alone. Similarly, the incorporation of the mineral scaffold matrix into the composite resulted in a higher specific surface area compared to the PCL frame alone. The increased specific surface area in the collagen-PCL composite promoted increased initial attachment of porcine adipose derived stem cells versus the PCL construct. PMID:27104930

  11. Structural insights into triple-helical collagen cleavage by matrix metalloproteinase 1

    OpenAIRE

    Manka, Szymon W; Carafoli, Federico; Visse, Robert; Bihan, Dominique; Raynal, Nicolas; Farndale, Richard W.; Murphy, Gillian; Enghild, Jan Johannes; Hohenester, Erhard; Nagase, Hideaki

    2012-01-01

    Collagenases of the matrix metalloproteinase (MMP) family play major roles in morphogenesis, tissue repair, and human diseases, but how they recognize and cleave the collagen triple helix is not fully understood. Here, we report temperature-dependent binding of a catalytically inactive MMP-1 mutant (E200A) to collagen through the cooperative action of its catalytic and hemopexin domains. Contact between the two molecules was mapped by screening the Collagen Toolkit peptide library and by hydr...

  12. Propolis Modifies Collagen Types I and III Accumulation in the Matrix of Burnt Tissue

    OpenAIRE

    Pawel Olczyk; Grzegorz Wisowski; Katarzyna Komosinska-Vassev; Jerzy Stojko; Katarzyna Klimek; Monika Olczyk; Kozma, Ewa M.

    2013-01-01

    Wound healing represents an interactive process which requires highly organized activity of various cells, synthesizing cytokines, growth factors, and collagen. Collagen types I and III, serving as structural and regulatory molecules, play pivotal roles during wound healing. The aim of this study was to compare the propolis and silver sulfadiazine therapeutic efficacy throughout the quantitative and qualitative assessment of collagen types I and III accumulation in the matrix of burnt tissues...

  13. Manipulation of in vitro collagen matrix architecture for scaffolds of improved physiological relevance

    Science.gov (United States)

    Hapach, Lauren A.; VanderBurgh, Jacob A.; Miller, Joseph P.; Reinhart-King, Cynthia A.

    2015-12-01

    Type I collagen is a versatile biomaterial that is widely used in medical applications due to its weak antigenicity, robust biocompatibility, and its ability to be modified for a wide array of applications. As such, collagen has become a major component of many tissue engineering scaffolds, drug delivery platforms, and substrates for in vitro cell culture. In these applications, collagen constructs are fabricated to recapitulate a diverse set of conditions. Collagen fibrils can be aligned during or post-fabrication, cross-linked via numerous techniques, polymerized to create various fibril sizes and densities, and copolymerized into a wide array of composite scaffolds. Here, we review approaches that have been used to tune collagen to better recapitulate physiological environments for use in tissue engineering applications and studies of basic cell behavior. We discuss techniques to control fibril alignment, methods for cross-linking collagen constructs to modulate stiffness, and composite collagen constructs to better mimic physiological extracellular matrix.

  14. Lathyrism-induced alterations in collagen cross-links influence the mechanical properties of bone material without affecting the mineral

    Science.gov (United States)

    Paschalis, E.P.; Tatakis, D.N.; Robins, S.; Fratzl, P.; Manjubala, I.; Zoehrer, R.; Gamsjaeger, S.; Buchinger, B.; Roschger, A.; Phipps, R.; Boskey, A.L.; Dall'Ara, E.; Varga, P.; Zysset, P.; Klaushofer, K.; Roschger, P.

    2011-01-01

    In the present study a rat animal model of lathyrism was employed to decipher whether anatomically confined alterations in collagen cross-links are sufficient to influence the mechanical properties of whole bone. Animal experiments were performed under an ethics committee approved protocol. Sixty-four female (47 day old) rats of equivalent weights were divided into four groups (16 per group): Controls were fed a semi-synthetic diet containing 0.6% calcium and 0.6% phosphorus for 2 or 4 weeks and β-APN treated animals were fed additionally with β-aminopropionitrile (0.1% dry weight). At the end of this period the rats in the four groups were sacrificed, and L2–L6 vertebra were collected. Collagen cross-links were determined by both biochemical and spectroscopic (Fourier transform infrared imaging (FTIRI)) analyses. Mineral content and distribution (BMDD) were determined by quantitative backscattered electron imaging (qBEI), and mineral maturity/crystallinity by FTIRI techniques. Micro-CT was used to describe the architectural properties. Mechanical performance of whole bone as well as of bone matrix material was tested by vertebral compression tests and by nano-indentation, respectively. The data of the present study indicate that β-APN treatment changed whole vertebra properties compared to non-treated rats, including collagen cross-links pattern, trabecular bone volume to tissue ratio and trabecular thickness, which were all decreased (p < 0.05). Further, compression tests revealed a significant negative impact of β-APN treatment on maximal force to failure and energy to failure, while stiffness was not influenced. Bone mineral density distribution (BMDD) was not altered either. At the material level, β-APN treated rats exhibited increased Pyd/Divalent cross-link ratios in areas confined to a newly formed bone. Moreover, nano-indentation experiments showed that the E-modulus and hardness were reduced only in newly formed bone areas under the influence

  15. Improving nanoparticle diffusion through tumor collagen matrix by photo-thermal gold nanorods

    Science.gov (United States)

    Raeesi, Vahid; Chan, Warren C. W.

    2016-06-01

    Collagen (I) impairs the targeting of nanoparticles to tumor cells by obstructing their diffusion inside dense tumor interstitial matrix. This potentially makes large nanoparticles (>50 nm) reside near the tumor vessels and thereby compromises their functionality. Here we propose a strategy to locally improve nanoparticle transport inside collagen (I) component of the tumor tissue. We first used heat generating gold nanorods to alter collagen (I) matrix by local temperature elevation. We then explored this impact on the transport of 50 nm and 120 nm inorganic nanoparticles inside collagen (I). We demonstrated an increase in average diffusivity of 50 nm and 120 nm in the denatured collagen (I) by ~14 and ~21 fold, respectively, compared to intact untreated collagen (I) matrix. This study shows how nanoparticle-mediated hyperthermia inside tumor tissue can improve the transport of large nanoparticles through collagen (I) matrix. The ability to increase nanoparticles diffusion inside tumor stroma allows their targeting or other functionalities to take effect, thereby significantly improving cancer therapeutic or diagnostic outcome.Collagen (I) impairs the targeting of nanoparticles to tumor cells by obstructing their diffusion inside dense tumor interstitial matrix. This potentially makes large nanoparticles (>50 nm) reside near the tumor vessels and thereby compromises their functionality. Here we propose a strategy to locally improve nanoparticle transport inside collagen (I) component of the tumor tissue. We first used heat generating gold nanorods to alter collagen (I) matrix by local temperature elevation. We then explored this impact on the transport of 50 nm and 120 nm inorganic nanoparticles inside collagen (I). We demonstrated an increase in average diffusivity of 50 nm and 120 nm in the denatured collagen (I) by ~14 and ~21 fold, respectively, compared to intact untreated collagen (I) matrix. This study shows how nanoparticle-mediated hyperthermia inside

  16. Effect of collagen turnover and matrix metalloproteinase activity on healing of venous leg ulcers

    NARCIS (Netherlands)

    Meyer, F.J.; Burnand, K.G.; Abisi, S.; TeKoppele, J.M.; Els, B. van; Smith, A.

    2008-01-01

    Background: The presence of fibrous tissue in poorly healing venous leg ulcers suggests abnormal collagen metabolism. The aim was to determine whether there were differences in collagen turnover and matrix metalloproteinase (MMP) activity between ulcers that healed, those that did not heal and norma

  17. Preventive Effects of Collagen Peptide from Deer Sinew on Bone Loss in Ovariectomized Rats

    Directory of Open Access Journals (Sweden)

    He Zhang

    2014-01-01

    Full Text Available Deer sinew (DS has been used traditionally for various illnesses, and the major active constituent is collagen. In this study, we assessed the effects of collagen peptide from DS on bone loss in the ovariectomized rats. Wister female rats were randomly divided into six groups as follows: sham-operated (SHAM, ovariectomized control (OVX, OVX given 1.0 mg/kg/week nylestriol (OVX + N, OVX given 0.4 g/kg/day collagen peptide (OVX + H, OVX given 0.2 g/kg/day collagen peptide (OXV + M, and OVX given 0.1 g/kg/day collagen peptide (OXV + L, respectively. After 13 weeks of treatment, the rats were euthanized, and the effects of collagen peptide on body weight, uterine weight, bone mineral density (BMD, serum biochemical indicators, bone histomorphometry, and bone mechanics were observed. The data showed that BMD and concentration of serum hydroxyproline were significantly increased and the levels of serum calcium, phosphorus, and alkaline phosphatase were decreased. Besides, histomorphometric parameters and mechanical indicators were improved. However, collagen peptide of DS has no effect on estradiol level, body weight, and uterine weight. Therefore, these results suggest that the collagen peptide supplementation may also prevent and treat bone loss.

  18. Inelastic behaviour of collagen networks in cell–matrix interactions and mechanosensation

    OpenAIRE

    Mohammadi, Hamid; Arora, Pamma D.; Simmons, Craig A.; Janmey, Paul A.; McCulloch, Christopher A.

    2015-01-01

    The mechanical properties of extracellular matrix proteins strongly influence cell-induced tension in the matrix, which in turn influences cell function. Despite progress on the impact of elastic behaviour of matrix proteins on cell–matrix interactions, little is known about the influence of inelastic behaviour, especially at the large and slow deformations that characterize cell-induced matrix remodelling. We found that collagen matrices exhibit deformation rate-dependent behaviour, which le...

  19. Improving nanoparticle diffusion through tumor collagen matrix by photo-thermal gold nanorods.

    Science.gov (United States)

    Raeesi, Vahid; Chan, Warren C W

    2016-07-01

    Collagen (I) impairs the targeting of nanoparticles to tumor cells by obstructing their diffusion inside dense tumor interstitial matrix. This potentially makes large nanoparticles (>50 nm) reside near the tumor vessels and thereby compromises their functionality. Here we propose a strategy to locally improve nanoparticle transport inside collagen (I) component of the tumor tissue. We first used heat generating gold nanorods to alter collagen (I) matrix by local temperature elevation. We then explored this impact on the transport of 50 nm and 120 nm inorganic nanoparticles inside collagen (I). We demonstrated an increase in average diffusivity of 50 nm and 120 nm in the denatured collagen (I) by ∼14 and ∼21 fold, respectively, compared to intact untreated collagen (I) matrix. This study shows how nanoparticle-mediated hyperthermia inside tumor tissue can improve the transport of large nanoparticles through collagen (I) matrix. The ability to increase nanoparticles diffusion inside tumor stroma allows their targeting or other functionalities to take effect, thereby significantly improving cancer therapeutic or diagnostic outcome. PMID:26822539

  20. Nitrogen and carbon isotopic composition of bone collagen from marine and terrestrial animals

    Science.gov (United States)

    Schoeninger, Margaret J.; DeNiro, Michael J.

    1984-04-01

    The stable nitrogen and carbon isotope ratios of bone collagen prepared from more than 100 animals representing 66 species of birds, fish, and mammals are presented. The δ15N values of bone collagen from animals that fed exclusively in the marine environment are, on average, 9%. more positive than those from animals that fed exclusively in the terrestrial environment; ranges for the two groups overlap by less than 1%. Bone collagen δ15N values also serve to separate marine fish from the small number of freshwater fish we analyzed. The bone collagen δ15N values of birds and fish that spent part of their life cycles feeding in the marine environment and part in the freshwater environment are intermediate between those of animals that fed exclusively in one or the other system. Further, animals that fed at successive trophic levels in the marine and terrestrial environment are separated, on average, by a 3%. difference in the δ15N values of their bone collagen. Specifically, carnivorous and herbivorous terrestrial animals have mean δ15N values for bone collagen of + 8.0 and + 5.3%., respectively. Among marine animals, those that fed on fish have a mean δ15N value for bone collagen of + 16.5%., whereas those that fed on invertebrates have a mean δ15N value of + 13.3%. These results support previous suggestions of a 3%. enrichment in δ15N values at each successively higher trophic level. In contrast to the results for δ15N values, the ranges of bone collagen δ13C values from marine and terrestrial feeders overlap to a great extent. Additionally, bone collagen δ13C values do not reflect the trophic levels at which the animals fed. These results indicate that bone collagen δ15N values will be useful in determining relative dependence on marine and terrestrial food sources and in investigating trophic level relationships among different animal species within an ecosystem. This approach should be applicable to animals represented by prehistoric or fossilized

  1. Porcine collagen matrix for treating gingival recession. Randomized clinical trial.

    Directory of Open Access Journals (Sweden)

    Yuri Alejandro Castro

    2014-03-01

    Full Text Available ABSTRACT Achieving root coverage after exposure caused by gingival recession is one of the main goals of reconstructive periodontal surgery. Even though a large variety of techniques and mucogingival grafting procedures are available, their long-term results are not clear yet. Therefore, this study aimed to compare clinical effectiveness of the porcine collagen matrix with subepithelial connective graft for treating Miller class I and II gingival recessions. Materials and methods: The randomized clinical trial included twelve patients assigned to two groups. In the first group (experimental, six patients were treated using collagen matrix (mean age, 54.3 ± 5.6 years; mean recession 2. 67 ± 1.03 mm. Another group (control of six patients was treated using connective grafts (mean age, 57.1 ± 2.7 years; mean recession 4.33 ± 1.03 mm. All patients underwent periodontal evaluation and pre-surgical preparation including oral hygiene instruction and supragingival scaling. Gingival recessions were exposed through partial thickness flaps where the grafts and matrices were placed. Patients were assessed periodically until complete healing of tissue. Results: Root coverage parameters, amount of keratinized gingiva, gingival biotype and clinical attachment level were evaluated. The root coverage percentage for the group using connective graft was 24.7 ± 13.5 % and 16.6 ± 26.8 % for the one treated with the matrix. The amount of increased keratinized tissue was 4.33 ± 2.06 mm and 4.5 ± 0.83 mm for the control and experimental group respectively. Both groups increased gingival biotypes from thin to thick at 100%. The final clinical attachment level was 4.17 ± 3.17 ± 04mm for the control group and 0.98 mm for the experimental group. There were significant differences between the outcome of gingival recession and clinical attachment. Conclusion: Results indicate both techniques, besides being predictable, are useful for improving clinical parameters

  2. Diabetes-induced fibrotic matrix inhibits intramembranous bone healing

    OpenAIRE

    Khosravi, Roozbeh; Trackman, Philip C.

    2014-01-01

    Diabetes diminishes bone healing and ossification. Reduced bone formation in intramembranous ossification is known, yet the mechanism(s) behind impaired intramembranous bone healing are unclear. Here we report the formation of a fibrotic matrix during healing of intramembranous calvarial bone defects that appears to exclude new bone growth. Our histological analyses of 7-day and 14-day calvaria bone healing tissue in chemically-induced diabetic mice and non-diabetic mice showed the accumulati...

  3. Bony defect repair in rabbit using hybrid rapid prototyping polylactic co glycolic acid/β tricalciumphosphate collagen I/apatite scaffold and bone marrow mesenchymal stem cells

    Directory of Open Access Journals (Sweden)

    Long Pang

    2013-01-01

    Full Text Available Background: In bone tissue engineering, extracellular matrix exerts critical influence on cellular interaction with porous biomaterial and the apatite playing an important role in the bonding process of biomaterial to bone tissue. The aim of this study was to observe the therapeutic effects of hybrid rapid prototyping (RP scaffolds comprising polylactic-co-glycolic acid (PLGA, β-tricalciumphosphate (β-TCP, collagen I and apatite (PLGA/β-TCP-collagen I/apatite on segmental bone defects in conjunction with combination with bone marrow mesenchymal stem cells (BMSCs. Materials and Methods: BMSCs were seeded into the hybrid RP scaffolds to repair 15 mm defect in the radius of rabbits. Radiograph, microcomputed tomography and histology were used to evaluate new bone formation. Results: Radiographic analysis done from 12 to 36 weeks postoperative period demonstrated that new bone formed at the radial defect site and continues to increase until the medullary cavity is recanalized and remodelling is complete. The bone defect remained unconnected in the original RP scaffolds (PLGA/β-TCP during the whole study. Histological observations conformed to the radiographic images. In hybrid RP scaffold group, woven bone united the radial defect at 12 weeks and consecutively remodeled into lamellar bone 24 weeks postoperation and finally matured into cortical bone with normal marrow cavity after another 12 weeks. No bone formation but connective tissue has been detected in RP scaffold at the same time. Conclusion: Collagen I/apatite sponge composite coating could improve new bone formation in vivo. The hybrid RP scaffold of PLGA/β-TCP skeleton with collagen I/apatite sponge composite coating is a promising candidate for bone tissue engineering.

  4. THE DIFFERENTIAL REGULATION OF CELL MOTILE ACTIVITY THROUGH MATRIX STIFFNESS AND POROSITY IN THREE DIMENSIONAL COLLAGEN MATRICES

    Science.gov (United States)

    Miron-Mendoza, Miguel; Seemann, Joachim; Grinnell, Frederick

    2010-01-01

    In three dimensional collagen matrices, cell motile activity results in collagen translocation, cell spreading and cell migration. Cells can penetrate into the matrix as well as spread and migrate along its surface. In the current studies, we quantitatively characterize collagen translocation, cell spreading and cell migration in relationship to collagen matrix stiffness and porosity. Collagen matrices prepared with 1 to 4 mg/ml collagen exhibited matrix stiffness (storage modulus measured by oscillating rheometry) increasing from 4 to 60 Pa and matrix porosity (measured by scanning electron microscopy) decreasing from 4 to 1 μm2. Over this collagen concentration range, the consequences of cell motile activity changed markedly. As collagen concentration increased, cells no longer were able to cause translocation of collagen fibrils. Cell migration increased and cell spreading changed from dendritic to more flattened and polarized morphology depending on location of cells within or on the surface of the matrix. Collagen translocation appeared to depend primarily on matrix stiffness, whereas cell spreading and migration were less dependent on matrix stiffness and more dependent on collagen matrix porosity. PMID:20537378

  5. Chitosan-collagen porous scaffold and bone marrow mesenchymal stem cell transplantation for ischemic stroke

    Directory of Open Access Journals (Sweden)

    Feng Yan

    2015-01-01

    Full Text Available In this study, we successfully constructed a composite of bone marrow mesenchymal stem cells and a chitosan-collagen scaffold in vitro, transplanted either the composite or bone marrow mesenchymal stem cells alone into the ischemic area in animal models, and compared their effects. At 14 days after co-transplantation of bone marrow mesenchymal stem cells and the hitosan-collagen scaffold, neurological function recovered noticeably. Vascular endothelial growth factor expression and nestin-labeled neural precursor cells were detected in the ischemic area, surrounding tissue, hippocampal dentate gyrus and subventricular zone. Simultaneously, a high level of expression of glial fibrillary acidic protein and a low level of expression of neuron-specific enolase were visible in BrdU-labeled bone marrow mesenchymal stem cells. These findings suggest that transplantation of a composite of bone marrow mesenchymal stem cells and a chitosan-collagen scaffold has a neuroprotective effect following ischemic stroke.

  6. Chitosan-collagen porous scaffold and bone marrow mesenchymal stem cell transplantation for ischemic stroke

    Institute of Scientific and Technical Information of China (English)

    Feng Yan; Wei Yue; Yue-lin Zhang; Guo-chao Mao; Ke Gao; Zhen-xing Zuo; Ya-jing Zhang; Hui Lu

    2015-01-01

    In this study, we successfully constructed a composite of bone marrow mesenchymal stem cells and a chitosan-collagen scaffoldin vitro, transplanted either the composite or bone marrow mesenchymal stem cells alone into the ischemic area in animal models, and compared their effects. At 14 days after co-transplantation of bone marrow mesenchymal stem cells and the hi-tosan-collagen scaffold, neurological function recovered noticeably. Vascular endothelial growth factor expression and nestin-labeled neural precursor cells were detected in the ischemic area, surrounding tissue, hippocampal dentate gyrus and subventricular zone. Simultaneously, a high level of expression of glial ifbrillary acidic protein and a low level of expression of neuron-spe-ciifc enolase were visible in BrdU-labeled bone marrow mesenchymal stem cells. These ifndings suggest that transplantation of a composite of bone marrow mesenchymal stem cells and a chi-tosan-collagen scaffold has a neuroprotective effect following ischemic stroke.

  7. Propolis Modifies Collagen Types I and III Accumulation in the Matrix of Burnt Tissue

    Directory of Open Access Journals (Sweden)

    Pawel Olczyk

    2013-01-01

    Full Text Available Wound healing represents an interactive process which requires highly organized activity of various cells, synthesizing cytokines, growth factors, and collagen. Collagen types I and III, serving as structural and regulatory molecules, play pivotal roles during wound healing. The aim of this study was to compare the propolis and silver sulfadiazine therapeutic efficacy throughout the quantitative and qualitative assessment of collagen types I and III accumulation in the matrix of burnt tissues. Burn wounds were inflicted on pigs, chosen for the evaluation of wound repair because of many similarities between pig and human skin. Isolated collagen types I and III were estimated by the surface plasmon resonance method with a subsequent collagenous quantification using electrophoretic and densitometric analyses. Propolis burn treatment led to enhanced collagens and its components expression, especially during the initial stage of the study. Less expressed changes were observed after silver sulfadiazine (AgSD application. AgSD and, with a smaller intensity, propolis stimulated accumulation of collagenous degradation products. The assessed propolis therapeutic efficacy, throughout quantitatively and qualitatively analyses of collagen types I and III expression and degradation in wounds matrix, may indicate that apitherapeutic agent can generate favorable biochemical environment supporting reepithelization.

  8. Propolis Modifies Collagen Types I and III Accumulation in the Matrix of Burnt Tissue.

    Science.gov (United States)

    Olczyk, Pawel; Wisowski, Grzegorz; Komosinska-Vassev, Katarzyna; Stojko, Jerzy; Klimek, Katarzyna; Olczyk, Monika; Kozma, Ewa M

    2013-01-01

    Wound healing represents an interactive process which requires highly organized activity of various cells, synthesizing cytokines, growth factors, and collagen. Collagen types I and III, serving as structural and regulatory molecules, play pivotal roles during wound healing. The aim of this study was to compare the propolis and silver sulfadiazine therapeutic efficacy throughout the quantitative and qualitative assessment of collagen types I and III accumulation in the matrix of burnt tissues. Burn wounds were inflicted on pigs, chosen for the evaluation of wound repair because of many similarities between pig and human skin. Isolated collagen types I and III were estimated by the surface plasmon resonance method with a subsequent collagenous quantification using electrophoretic and densitometric analyses. Propolis burn treatment led to enhanced collagens and its components expression, especially during the initial stage of the study. Less expressed changes were observed after silver sulfadiazine (AgSD) application. AgSD and, with a smaller intensity, propolis stimulated accumulation of collagenous degradation products. The assessed propolis therapeutic efficacy, throughout quantitatively and qualitatively analyses of collagen types I and III expression and degradation in wounds matrix, may indicate that apitherapeutic agent can generate favorable biochemical environment supporting reepithelization.

  9. Nanofibrous yet injectable polycaprolactone-collagen bone tissue scaffold with osteoprogenitor cells and controlled release of bone morphogenetic protein-2

    Energy Technology Data Exchange (ETDEWEB)

    Subramanian, Gayathri; Bialorucki, Callan [Department of Bioengineering, College of Engineering, University of Toledo, Toledo, OH 43606 (United States); Yildirim-Ayan, Eda, E-mail: eda.yildirimayan@utoledo.edu [Department of Bioengineering, College of Engineering, University of Toledo, Toledo, OH 43606 (United States); Department of Orthopaedic Surgery, University of Toledo Medical Center, Toledo, OH 43614 (United States)

    2015-06-01

    In this work, we developed a nanofibrous, yet injectable orthobiologic tissue scaffold that is capable of hosting osteoprogenitor cells and controlling kinetic release profile of the encapsulated pro-osteogenic factor without diminishing its bioactivity over 21 days. This innovative injectable scaffold was synthesized by incorporating electrospun and subsequently O{sub 2} plasma-functionalized polycaprolactone (PCL) nanofibers within the collagen type-I solution along with MC3T3-E1 cells (pre-osteoblasts) and bone morphogenetic protein-2 (BMP2). Through changing the PCL nanofiber concentration within the injectable scaffolds, we were able to tailor the mechanical strength, protein retention capacity, bioactivity preservation, and osteoinductive potential of the scaffolds. The nanofibrous internal structure of the scaffold allowed us to use a low dose of BMP2 (200 ng/ml) to achieve osteoblastic differentiation in in vitro culture. The osteogenesis capacity of the injectable scaffolds were evaluated though measuring MC3T3-E1 cell proliferation, ALP activity, matrix mineralization, and early- and late-osteoblast specific gene expression profiles over 21 days. The results demonstrated that the nanofibrous injectable scaffold provides not only an osteoinductive environment for osteoprogenitor cells to differentiate, but also a suitable biomechanical and biochemical environment to act as a reservoir for osteogenic factors with controlled release profile. - Highlights: • Injectable nanofibrous scaffold with osteoprogenitor cells and BMP2 was synthesized. • PCL nanofiber concentration within collagen scaffold affected the BMP2 retention and bioactivity. • Optimal PCL concentration was identified for mechanical stability, injectability, and osteogenic activity. • Scaffolds exhibited long-term osteoinductive capacity for bone repair and regeneration.

  10. Rheological, biocompatibility and osteogenesis assessment of fish collagen scaffold for bone tissue engineering.

    Science.gov (United States)

    Elango, Jeevithan; Zhang, Jingyi; Bao, Bin; Palaniyandi, Krishnamoorthy; Wang, Shujun; Wenhui, Wu; Robinson, Jeya Shakila

    2016-10-01

    In the present investigation, an attempt was made to find an alternative to mammalian collagen with better osteogenesis ability. Three types of collagen scaffolds - collagen, collagen-chitosan (CCH), and collagen-hydroxyapatite (CHA) - were prepared from the cartilage of Blue shark and investigated for their physico-functional and mechanical properties in relation to biocompatibility and osteogenesis. CCH scaffold was superior with pH 4.5-4.9 and viscosity 9.7-10.9cP. Notably, addition of chitosan and HA (hydroxyapatite) improved the stiffness (11-23MPa) and degradation rate but lowered the water binding capacity and porosity of the scaffold. Interestingly, CCH scaffolds remained for 3days before complete in-vitro biodegradation. The decreased amount of viable T-cells and higher level of FAS/APO-1 were substantiated the biocompatibility properties of prepared collagen scaffolds. Osteogenesis study revealed that the addition of CH and HA in both fish and mammalian collagen scaffolds could efficiently promote osteoblast cell formation. The ALP activity was significantly high in CHA scaffold-treated osteoblast cells, which suggests an enhanced bone-healing process. Therefore, the present study concludes that the composite scaffolds prepared from fish collagen with higher stiffness, lower biodegradation rate, better biocompatible, and osteogenesis properties were suitable biomaterial for a bone tissue engineering application as an alternative to mammalian collagen scaffolds. PMID:27211297

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

    Science.gov (United States)

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

    2016-10-01

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

  12. Fabrication of nano-hydroxyapatite/collagen/osteonectin composites for bone graft applications

    Energy Technology Data Exchange (ETDEWEB)

    Liao, Susan; Ngiam, Michelle; Chan, Casey K; Ramakrishna, S [Division of Bioengineering, Nanoscience and Nanotechnology Initiative, Faculty of Engineering, National University of Singapore, 117576 (Singapore)

    2009-04-15

    Mineralized type I collagen (collagen I) nanofibers and their nanofibril bundles make up the microstructure of natural bone tissue, which range from nanometers to micrometers. However, attempts to achieve this hierarchically assembled structure in vitro have been unsuccessful. In this study, we added osteonectin into the collagen I solution, either at a high or low weight ratio (osteonectin: collagen I = 1:30 or 1:90) before co-precipitation. Results indicated that spindle-like nano-hydroxyapatite (nano-HA) was deposited on collagen/osteonectin and pure osteonectin (control) groups. Furthermore, transmission electron microscope (TEM) and scanning electron microscope (SEM) results showed that the assembled mineralized fiber bundles were formed randomly at different levels from 50 nm, 250 nm to 1100 nm. However, when we replaced collagen I with collagen II, osteonectin addition did not induce the formation of mineralized fiber bundles. The participation of osteonectin in the assembly of the mineralized fibers could provide new insights into the novel mineralization function of osteonectin for bone development in vivo and advancing new biomimetic methods for bone graft applications.

  13. Development of a nanofiltration method for bone collagen 14C AMS dating

    Science.gov (United States)

    Boudin, Mathieu; Boeckx, Pascal; Buekenhoudt, Anita; Vandenabeele, Peter; Van Strydonck, Mark

    2013-01-01

    Radiocarbon dating of bones is usually performed on the collagen fraction. However, this collagen can contain exogenous molecules, including humic substances (HSs) and/or other soil components that may have a different age than the bone. Incomplete removal can result in biased 14C dates. Ultrafiltration of collagen, dissolved as gelatin (molecular weight (MW) ∼100,000 Dalton), has received considerable attention to obtain more reliable dates. Ultrafiltration is an effective method of removal of low-molecular weight contaminants from bone collagen but it does not remove high-molecular weight contaminants, such as cross-linked humic collagen complexes. However, comparative dating studies have raised the question whether this cleaning step itself may introduce contamination with carbon from the filters used. In this study, a nanofiltration method was developed using a ceramic filter to avoid a possible extraneous carbon contamination introduced by the filter. This method should be applicable to various protein materials e.g. collagen, silk, wool, leather and should be able to remove low-molecular and high molecular weight HSs. In this study bone collagen was hot acid hydrolyzed to amino acids and nanofiltrated. A filter with a molecular weight cutoff (MWCO) of 450 Dalton was chosen in order to collect the amino acids in the permeate and the HSs in the retentate. Two pilot studies were set up. Two nanofiltration types were tested in pilot study 1: dead end and cross flow filtration. Humic substance (HS)-solutions with fossil carbon and modern hydrolyzed collagen contaminated with HSs were filtrated and analyzed with spectrofluorescence to determine the HS removal. Cross flow nanofiltration showed the most efficient HS removal. A second pilot study based upon these results was set up wherein only cross flow filtration was performed. 14C measurements of the permeates of hydrolyzed modern collagen contaminated with fossil HSs demonstrate a significant but incomplete

  14. Development of a nanofiltration method for bone collagen 14C AMS dating

    International Nuclear Information System (INIS)

    Radiocarbon dating of bones is usually performed on the collagen fraction. However, this collagen can contain exogenous molecules, including humic substances (HSs) and/or other soil components that may have a different age than the bone. Incomplete removal can result in biased 14C dates. Ultrafiltration of collagen, dissolved as gelatin (molecular weight (MW) ∼100,000 Dalton), has received considerable attention to obtain more reliable dates. Ultrafiltration is an effective method of removal of low-molecular weight contaminants from bone collagen but it does not remove high-molecular weight contaminants, such as cross-linked humic collagen complexes. However, comparative dating studies have raised the question whether this cleaning step itself may introduce contamination with carbon from the filters used. In this study, a nanofiltration method was developed using a ceramic filter to avoid a possible extraneous carbon contamination introduced by the filter. This method should be applicable to various protein materials e.g. collagen, silk, wool, leather and should be able to remove low-molecular and high molecular weight HSs. In this study bone collagen was hot acid hydrolyzed to amino acids and nanofiltrated. A filter with a molecular weight cutoff (MWCO) of 450 Dalton was chosen in order to collect the amino acids in the permeate and the HSs in the retentate. Two pilot studies were set up. Two nanofiltration types were tested in pilot study 1: dead end and cross flow filtration. Humic substance (HS)-solutions with fossil carbon and modern hydrolyzed collagen contaminated with HSs were filtrated and analyzed with spectrofluorescence to determine the HS removal. Cross flow nanofiltration showed the most efficient HS removal. A second pilot study based upon these results was set up wherein only cross flow filtration was performed. 14C measurements of the permeates of hydrolyzed modern collagen contaminated with fossil HSs demonstrate a significant but incomplete

  15. Development of a nanofiltration method for bone collagen {sup 14}C AMS dating

    Energy Technology Data Exchange (ETDEWEB)

    Boudin, Mathieu, E-mail: mathieu.boudin@ugent.be [Royal Institute for Cultural Heritage, Jubelpark 1, B-1000 Brussels (Belgium); Ghent University, Faculty of Bioscience Engineering, Laboratory of Applied Physical Chemistry, Coupure Links 653, B-9000 Ghent (Belgium); Boeckx, Pascal [Ghent University, Faculty of Bioscience Engineering, Laboratory of Applied Physical Chemistry, Coupure Links 653, B-9000 Ghent (Belgium); Buekenhoudt, Anita [Flemish Institute for Technological Research, Separation and Conversion Technology, Boeretang 200, B-2400 Mol (Belgium); Vandenabeele, Peter [Ghent University, Department of Archaeology, Sint-Pietersnieuwstraat 35, B-9000 Ghent (Belgium); Van Strydonck, Mark [Royal Institute for Cultural Heritage, Jubelpark 1, B-1000 Brussels (Belgium)

    2013-01-15

    Radiocarbon dating of bones is usually performed on the collagen fraction. However, this collagen can contain exogenous molecules, including humic substances (HSs) and/or other soil components that may have a different age than the bone. Incomplete removal can result in biased {sup 14}C dates. Ultrafiltration of collagen, dissolved as gelatin (molecular weight (MW) {approx}100,000 Dalton), has received considerable attention to obtain more reliable dates. Ultrafiltration is an effective method of removal of low-molecular weight contaminants from bone collagen but it does not remove high-molecular weight contaminants, such as cross-linked humic collagen complexes. However, comparative dating studies have raised the question whether this cleaning step itself may introduce contamination with carbon from the filters used. In this study, a nanofiltration method was developed using a ceramic filter to avoid a possible extraneous carbon contamination introduced by the filter. This method should be applicable to various protein materials e.g. collagen, silk, wool, leather and should be able to remove low-molecular and high molecular weight HSs. In this study bone collagen was hot acid hydrolyzed to amino acids and nanofiltrated. A filter with a molecular weight cutoff (MWCO) of 450 Dalton was chosen in order to collect the amino acids in the permeate and the HSs in the retentate. Two pilot studies were set up. Two nanofiltration types were tested in pilot study 1: dead end and cross flow filtration. Humic substance (HS)-solutions with fossil carbon and modern hydrolyzed collagen contaminated with HSs were filtrated and analyzed with spectrofluorescence to determine the HS removal. Cross flow nanofiltration showed the most efficient HS removal. A second pilot study based upon these results was set up wherein only cross flow filtration was performed. {sup 14}C measurements of the permeates of hydrolyzed modern collagen contaminated with fossil HSs demonstrate a significant

  16. Increasing extracellular matrix collagen level and MMP activity induces cyst development in polycystic kidney disease

    Directory of Open Access Journals (Sweden)

    Liu Bin

    2012-09-01

    Full Text Available Abstract Background Polycystic Kidney Disease (PKD kidneys exhibit increased extracellular matrix (ECM collagen expression and metalloproteinases (MMPs activity. We investigated the role of these increases on cystic disease progression in PKD kidneys. Methods We examined the role of type I collagen (collagen I and membrane bound type 1 MMP (MT1-MMP on cyst development using both in vitro 3 dimensional (3D collagen gel culture and in vivo PCK rat model of PKD. Results We found that collagen concentration is critical in controlling the morphogenesis of MDCK cells cultured in 3D gels. MDCK cells did not form 3D structures at collagen I concentrations lower than 1 mg/ml but began forming tubules when the concentration reaches 1 mg/ml. Significantly, these cells began to form cyst when collagen I concentration reached to 1.2 mg/ml, and the ratios of cyst to tubule structures increased as the collagen I concentration increased. These cells exclusively formed cyst structures at a collagen I concentration of 1.8 mg/ml or higher. Overexpression of MT1-MMP in MDCK cells significantly induced cyst growth in 3D collagen gel culture. Conversely, inhibition of MMPs activity with doxycycline, a FDA approved pan-MMPs inhibitor, dramatically slowed cyst growth. More importantly, the treatment of PCK rats with doxycycline significantly decreased renal tubule cell proliferation and markedly inhibited the cystic disease progression. Conclusions Our data suggest that increased collagen expression and MMP activity in PKD kidneys may induce cyst formation and expansion. Our findings also suggest that MMPs may serve as a therapeutic target for the treatment of human PKD.

  17. PGA-incorporated collagen: Toward a biodegradable composite scaffold for bone-tissue engineering.

    Science.gov (United States)

    Toosi, Shirin; Naderi-Meshkin, Hojjat; Kalalinia, Fatemeh; Peivandi, Mohammad Taghi; HosseinKhani, Hossein; Bahrami, Ahmad Reza; Heirani-Tabasi, Asieh; Mirahmadi, Mahdi; Behravan, Javad

    2016-08-01

    Nowadays composite scaffolds based on synthetic and natural biomaterials have got attention to increase healing of non-union bone fractures. To this end, different aspects of collagen sponge incorporated with poly(glycolic acid) (PGA) fiber were investigated in this study. Collagen solution (6.33 mg/mL) with PGA fibers (collagen/fiber ratio [w/w]: 4.22, 2.11, 1.06, 0.52) was freeze-dried, followed by dehydrothermal cross-linking to obtain collagen sponge incorporating PGA fibers. Properties of scaffold for cell viability, proliferation, and differentiation of mesenchymal stem cells (MSCs) were evaluated. Scanning electron microscopy showed that collagen sponge exhibited an interconnected pore structure with an average pore size of 190 μm, irrespective of PGA fiber incorporation. The collagen-PGA sponge was superior to the original collagen sponge in terms of the initial attachment, proliferation rate, and osteogenic differentiation of the bone marrow-MSCs (BM-MSC). The shrinkage of sponges during cell culture was significantly suppressed by fiber incorporation. Incorporation of PGA fiber is a simple and promising way to reinforce collagen sponge without impairing biocompatibility. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 2020-2028, 2016. PMID:27059133

  18. Extracellular matrix of smooth muscle cells: interaction of collagen type V with heparan sulfate proteoglycan

    International Nuclear Information System (INIS)

    Alteration in the extracellular matrix produced by smooth muscle cells may play a role in the development of atherosclerotic lesions. Consequently the authors have initiated studies on the structural organization of the extracellular matrix produced by cultured smooth muscle cells. Immunohisotological examination of this matrix using well-characterized mono- and polyclonal antibodies showed a partial codistribution of heparan sulfate (HS) proteoglycans with a number of different matrix components including collagen types I, III, IV, V and VI, laminin and fibronectin. Subsequent binding studies between isolated matrix proteins and HS showed that the polysaccharide interacts strongly with type V collagen and to a lesser extent with fibronectin as well as collagen types III and VI. The interaction between type V and HS was readily inhibited by heparin and highly sulfated HS but not be dermatan sulfate, chondroitin sulfate or HS with a low sulfate content. Furthermore, [35S]-HS proteoglycans isolated from cultured smooth muscle cells could be adsorbed on a column of sepharose conjugated with native type V collagen and eluted in a salt gradient. Hence, the interaction between type V and HS may play a major part in stabilizing the extracellular matrix of the vessel wall

  19. Collagen immobilization of multi-layered BCP-ZrO{sub 2} bone substitutes to enhance bone formation

    Energy Technology Data Exchange (ETDEWEB)

    Linh, Nguyen Thuy Ba [Department of Regenerative Medicine, College of Medicine, Soonchunhyang University, Cheonan, 330-090 (Korea, Republic of); Institute of Tissue Regeneration, College of Medicine, Soonchunhyang University, Cheonan, 330-090 (Korea, Republic of); Jang, Dong-Woo [Department of Regenerative Medicine, College of Medicine, Soonchunhyang University, Cheonan, 330-090 (Korea, Republic of); Lee, Byong-Taek, E-mail: lbt@sch.ac.kr [Department of Regenerative Medicine, College of Medicine, Soonchunhyang University, Cheonan, 330-090 (Korea, Republic of); Institute of Tissue Regeneration, College of Medicine, Soonchunhyang University, Cheonan, 330-090 (Korea, Republic of)

    2015-08-01

    Graphical abstract: - Highlights: • Col-BCP-ZrO. • Collagen fibers were formed and attached firmly on the surface of BCP-ZrO. • Highly interconnected but uniform porosity were obtained. • High biocompatible, strength scaffolds and new bone were evident in Col-BCP-ZrO{sub 2}. - Abstract: A porous microstructure of multi-layered BCP-ZrO{sub 2} bone substitutes was fabricated using the sponge replica method in which the highly interconnected structure was immobilized with collagen via ethyl(dimethylaminopropyl)carbodiimide/N-hydroxysuccinimide crosslinking. Their struts are combined with a three-layered BCP/BCP-ZrO{sub 2}/ZrO{sub 2} microstructure. Collagen fibers were firmly attached to the strut surface of the BCP-ZrO{sub 2} scaffolds. With control of the three-layered microstructure and collagen immobilization, the compressive strength of the scaffolds increased significantly to 6.8 MPa compared to that of the monolithic BCP scaffolds (1.3 MPa). An in vitro study using MTT, confocal observation, and real-time polymer chain reaction analysis demonstrated that the proliferation and differentiation of the pre-osteoblast-like MC3T3-E1 cells was improved due to the collagen incorporation. Remarkable enhancement of bone regeneration was observed without any immunological reaction in the femurs of rabbits during 1 and 5 months of implantation. Furthermore, the interfaces between new bone and the scaffold struts bonded directly without any gaps.

  20. Collagen immobilization of multi-layered BCP-ZrO2 bone substitutes to enhance bone formation

    International Nuclear Information System (INIS)

    Graphical abstract: - Highlights: • Col-BCP-ZrO. • Collagen fibers were formed and attached firmly on the surface of BCP-ZrO. • Highly interconnected but uniform porosity were obtained. • High biocompatible, strength scaffolds and new bone were evident in Col-BCP-ZrO2. - Abstract: A porous microstructure of multi-layered BCP-ZrO2 bone substitutes was fabricated using the sponge replica method in which the highly interconnected structure was immobilized with collagen via ethyl(dimethylaminopropyl)carbodiimide/N-hydroxysuccinimide crosslinking. Their struts are combined with a three-layered BCP/BCP-ZrO2/ZrO2 microstructure. Collagen fibers were firmly attached to the strut surface of the BCP-ZrO2 scaffolds. With control of the three-layered microstructure and collagen immobilization, the compressive strength of the scaffolds increased significantly to 6.8 MPa compared to that of the monolithic BCP scaffolds (1.3 MPa). An in vitro study using MTT, confocal observation, and real-time polymer chain reaction analysis demonstrated that the proliferation and differentiation of the pre-osteoblast-like MC3T3-E1 cells was improved due to the collagen incorporation. Remarkable enhancement of bone regeneration was observed without any immunological reaction in the femurs of rabbits during 1 and 5 months of implantation. Furthermore, the interfaces between new bone and the scaffold struts bonded directly without any gaps

  1. Osteogenic Matrix Cell Sheets Facilitate Osteogenesis in Irradiated Rat Bone

    Directory of Open Access Journals (Sweden)

    Yoshinobu Uchihara

    2015-01-01

    Full Text Available Reconstruction of large bone defects after resection of malignant musculoskeletal tumors is a significant challenge in orthopedic surgery. Extracorporeal autogenous irradiated bone grafting is a treatment option for bone reconstruction. However, nonunion often occurs because the osteogenic capacity is lost by irradiation. In the present study, we established an autogenous irradiated bone graft model in the rat femur to assess whether osteogenic matrix cell sheets improve osteogenesis of the irradiated bone. Osteogenic matrix cell sheets were prepared from bone marrow-derived stromal cells and co-transplanted with irradiated bone. X-ray images at 4 weeks after transplantation showed bridging callus formation around the irradiated bone. Micro-computed tomography images at 12 weeks postoperatively showed abundant callus formation in the whole circumference of the irradiated bone. Histology showed bone union between the irradiated bone and host femur. Mechanical testing showed that the failure force at the irradiated bone site was significantly higher than in the control group. Our study indicates that osteogenic matrix cell sheet transplantation might be a powerful method to facilitate osteogenesis in irradiated bones, which may become a treatment option for reconstruction of bone defects after resection of malignant musculoskeletal tumors.

  2. The extracellular matrix of Gadus morhua muscle contains types III, V, VI and IV collagens in addition to type I

    DEFF Research Database (Denmark)

    Brüggemann, Dagmar Adeline; Lawson, M.A.

    2005-01-01

    Confocal microscopy and immuno‐histochemistry were used to examine collagens in the extracellular matrix of cod Gadus morhua swimming muscle. In addition to the well known presence of type I fibrous collagen, types III and VI were also found in the myocommata and the endomysium. The beaded collagen...

  3. Determination of osteogenic or adipogenic lineages in muscle-derived stem cells (MDSCs) by a collagen-binding peptide (CBP) derived from bone sialoprotein (BSP)

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Yoon Jung [Dental Regenerative Biotechnology Major, School of Dentistry and Dental Research Institute, Seoul National University, Seoul 110-749 (Korea, Republic of); Lee, Jue Yeon [Research Institute, Nano Intelligent Biomedical Engineering Corporation (NIBEC), Seoul (Korea, Republic of); Lee, Seung Jin [Department of Industrial Pharmacy, College of Pharmacy, Ewha Womans University, Seoul (Korea, Republic of); Chung, Chong-Pyoung, E-mail: ccpperio@snu.ac.kr [Research Institute, Nano Intelligent Biomedical Engineering Corporation (NIBEC), Seoul (Korea, Republic of); Department of Periodontology, School of Dentistry and Dental Research Institute, Seoul National University, Seoul (Korea, Republic of); Park, Yoon Jeong, E-mail: parkyj@snu.ac.kr [Dental Regenerative Biotechnology Major, School of Dentistry and Dental Research Institute, Seoul National University, Seoul 110-749 (Korea, Republic of); Research Institute, Nano Intelligent Biomedical Engineering Corporation (NIBEC), Seoul (Korea, Republic of)

    2012-03-09

    Highlights: Black-Right-Pointing-Pointer CBP sequence is identified from BSP and has collagen binding activity. Black-Right-Pointing-Pointer CBP directly activates the MAPK signaling, especially ERK1/2. Black-Right-Pointing-Pointer CBP increase osteoblastic differentiation by the activation of Runx2. Black-Right-Pointing-Pointer CBP decrease adipogenic differentiation by the inhibition of PPAR{gamma}. -- Abstract: Bone sialoprotein (BSP) is a mineralized, tissue-specific, non-collagenous protein that is normally expressed only in mineralized tissues such as bone, dentin, cementum, and calcified cartilage, and at sites of new mineral formation. The binding of BSP to collagen is thought to be important for initiating bone mineralization and bone cell adhesion to the mineralized matrix. Several recent studies have isolated stem cells from muscle tissue, but their functional properties are still unclear. In this study, we examined the effects of a synthetic collagen-binding peptide (CBP) on the differentiation efficiency of muscle-derived stem cells (MDSCs). The CBP sequence (NGVFKYRPRYYLYKHAYFYPHLKRFPVQ) corresponds to residues 35-62 of bone sialoprotein (BSP), which are located within the collagen-binding domain in BSP. Interestingly, this synthetic CBP inhibited adipogenic differentiation but increased osteogenic differentiation in MDSCs. The CBP also induced expression of osteoblastic marker proteins, including alkaline phosphatase (ALP), type I collagen, Runt-related transcription factor 2 (Runx2), and osteocalcin; prevented adipogenic differentiation in MDSCs; and down-regulated adipose-specific mRNAs, such as adipocyte protein 2 (aP2) and peroxisome proliferator-activated receptor {gamma}. The CBP increased Extracellular signal-regulated kinases (ERK) 1/2 protein phosphorylation, which is important in lineage determination. These observations suggest that this CBP determines the osteogenic or adipogenic lineage in MDSCs by activating ERK1/2. Taken together, a

  4. Cervical collagen imaging for determining preterm labor risks using a colposcope with full Mueller matrix capability

    Science.gov (United States)

    Stoff, Susan; Chue-Sang, Joseph; Holness, Nola A.; Gandjbakhche, Amir; Chernomordik, Viktor; Ramella-Roman, Jessica

    2016-02-01

    Preterm birth is a worldwide health issue, as the number one cause of infant mortality and neurological disorders. Although affecting nearly 10% of all births, an accurate, reliable diagnostic method for preterm birth has, yet, to be developed. The primary constituent of the cervix, collagen, provides the structural support and mechanical strength to maintain cervical closure, through specific organization, during fetal gestation. As pregnancy progresses, the disorganization of the cervical collagen occurs to allow eventual cervical pliability so the baby can be birthed through the cervical opening. This disorganization of collagen affects the mechanical properties of the cervix and, if the changes occur prematurely, may be a significant factor leading to preterm birth. The organization of collagen can be analyzed through the use of Mueller Matrix Polarimetric imaging of the characteristic birefringence of collagen. In this research, we have built a full Mueller Matrix Polarimetry attachment to a standard colposcope to enable imaging of human cervixes during standard prenatal exams at various stages of fetal gestation. Analysis of the polarimetric images provides information of quantity and organization of cervical collagen at specific gestational stages of pregnancy. This quantitative information may provide an indication of risk of preterm birth.

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

    Science.gov (United States)

    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

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

  8. Induced Elastic Matrix Deposition Within Three-Dimensional Collagen Scaffolds

    OpenAIRE

    Venkataraman, Lavanya; Ramamurthi, Anand

    2011-01-01

    The structural stability of a cyclically distending elastic artery and the healthy functioning of vascular smooth muscle cells (SMCs) within are maintained by the presence of an intact elastic matrix and its principal protein, elastin. The accelerated degradation of the elastic matrix, which occurs in several vascular diseases, coupled with the poor ability of adult SMCs to regenerate lost elastin, can therefore adversely impact vascular homeostasis. Similarly, efforts to tissue engineer elas...

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

    Science.gov (United States)

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

    2012-01-01

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

  10. Kinetics of gene expression and bone remodelling in the clinical phase of collagen induced arthritis

    DEFF Research Database (Denmark)

    Denninger, Katja Caroline Marie; Litman, Thomas; Marstrand, Troels;

    2015-01-01

    ), and secreted phosphoprotein 1 (Spp1). Pregnancy-associated protein A (Pappa) and periostin (Postn), differentially expressed in the early disease phase, are proposed to participate in bone formation, and we suggest that they play a role in early bone formation in the CIA model. Comparison to human genome......Introduction: Pathological bone changes differ considerably between inflammatory arthritic diseases and most studies have focused on bone erosion. Collagen-induced arthritis (CIA) is a model for rheumatoid arthritis, which, in addition to bone erosion, demonstrates bone formation at the time...... of clinical manifestations. The objective of this study was to use this model to characterise the histological and molecular changes in bone remodelling, and relate these to the clinical disease development. Methods: A histological and gene expression profiling time-course study on bone remodelling in CIA...

  11. Study on de novo collagen biosynthesis and degradation markers of bone

    International Nuclear Information System (INIS)

    This investigation was carried out to study the performance of de novo biochemical markers of serum pro collagen type-1 amino terminal extension (PINP), as a marker of collagen biosynthesis, and urinary collagen crosslink free deoxypyridinoline (DPD) as a marker of collagen degradation. Moreover, urinary calcium C Ca) and inorganic phosphorus (P), as markers of bone demineralization, in addition to urinary creatinine (Cr), to reflect status of renal function, were also studied in order to assess the activity of bone turnover in osteoporotic (OST), postmenopausal (POST), peri menopausal(PERI), premenopausal (PRE) women and also in young adult (YON) ones. The obtained results showed that urinary creatinine levels were within the normal ranges in all women even in the elderly osteoporotic and postmenopausal women. Serum PINP did not reflect osteoblastic activity. Urinary DPD proved to be a good marker in monitoring the postmenopausal bone resorption and urinary Ca was a reliable marker for bone loss in osteoporosis and bone turnover in the postmenopausal status

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

    Science.gov (United States)

    Ornoy, A; Atkin, I; Levy, J

    1980-01-01

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

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

    Science.gov (United States)

    Ornoy, A; Atkin, I; Levy, J

    1980-01-01

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

  14. Development of a biomimetic collagen-hydroxyapatite scaffold for bone tissue engineering using a SBF immersion technique.

    OpenAIRE

    Al-Munajjed, Amir A; Plunkett, Niamh A; Gleeson, John P.; Weber, Tim; Jungreuthmayer, Christian; Levingstone, Tanya; Hammer, Joachim; O'Brien, Fergal J.

    2009-01-01

    The objective of this study was to develop a biomimetic, highly porous collagen-hydroxyapatite (HA) composite scaffold for bone tissue engineering (TE), combining the biological performance and the high porosity of a collagen scaffold with the high mechanical stiffness of a HA scaffold. Pure collagen scaffolds were produced using a lyophilization process and immersed in simulated body fluid (SBF) to provide a biomimetic coating. Pure collagen scaffolds served as a control. The mechanical, mat...

  15. Antibacterial and osteoinductive properties of demineralized bone matrix treated with silver

    Energy Technology Data Exchange (ETDEWEB)

    Kramer, S.J.; Spadaro, J.A.; Webster, D.A.

    The problems incurred by storage of demineralized bone allograft material and its potential use in contaminated operative sites make an antibacterial property desirable. Silver was considered for this role because of its wide spectrum of antibacterial susceptibility, low incidence of resistance, and its ability to persistently inhibit bacteria after binding to collagen matrices. Demineralized bone matrix prepared from rat diaphyseal bone segments was treated by exposure fo AgCl, AgNO3 and NaNO3 solutions prior to lyophilization. The resulting material was tested for bacterial inhibition after incubation in saline solutions for various times and showed inhibition persisting for at least four weeks (Ag-treated material only). Silver treating the matrix was found to partially inhibit the osteoinductive capacity at 10(-3) and 10(-2) M but not at 10(-5) M as measured by intramuscular implantation in the rat for six weeks. Control and NaNo3-treated specimens showed normal bone growth as measured by ashing and by 99mTc binding, and confirmed by radiologic densities. Histologic sections showed dense microdeposits on dense material predominately near the decalcified bone surfaces, but also within the matrix. The results suggest that pretreatment with silver at concentrations in the 10(-4) range would render the implant material antibacterial, protect its sterility, and leave the osteoinductive capacity intact.

  16. Influence of Nano-HA Coated Bone Collagen to Acrylic (Polymethylmethacrylate Bone Cement on Mechanical Properties and Bioactivity.

    Directory of Open Access Journals (Sweden)

    Tao Li

    Full Text Available This research investigated the mechanical properties and bioactivity of polymethylmethacrylate (PMMA bone cement after addition of the nano-hydroxyapatite(HA coated bone collagen (mineralized collagen, MC.The MC in different proportions were added to the PMMA bone cement to detect the compressive strength, compression modulus, coagulation properties and biosafety. The MC-PMMA was embedded into rabbits and co-cultured with MG 63 cells to exam bone tissue compatibility and gene expression of osteogenesis.15.0%(wt impregnated MC-PMMA significantly lowered compressive modulus while little affected compressive strength and solidification. MC-PMMA bone cement was biologically safe and indicated excellent bone tissue compatibility. The bone-cement interface crosslinking was significantly higher in MC-PMMA than control after 6 months implantation in the femur of rabbits. The genes of osteogenesis exhibited significantly higher expression level in MC-PMMA.MC-PMMA presented perfect mechanical properties, good biosafety and excellent biocompatibility with bone tissues, which has profoundly clinical values.

  17. Minimal invasive surgery for unicameral bone cyst using demineralized bone matrix: a case series

    OpenAIRE

    Cho Hwan; Seo Sung; Park So; Park Jong; Shin Duk; Park Il

    2012-01-01

    Abstract Background Various treatments for unicameral bone cyst have been proposed. Recent concern focuses on the effectiveness of closed methods. This study evaluated the effectiveness of demineralized bone matrix as a graft material after intramedullary decompression for the treatment of unicameral bone cysts. Methods Between October 2008 and June 2010, twenty-five patients with a unicameral bone cyst were treated with intramedullary decompression followed by grafting of demineralized bone ...

  18. The skin autofluorescence reflects the posttranslational glycation grade of the matrix protein collagen.

    Science.gov (United States)

    Jacobs, Kathleen; Navarrete Santos, Alexander; Simm, Andreas; Silber, Rolf-Edgar; Hofmann, Britt

    2014-10-01

    Advanced glycation end products (AGEs) seem to be involved in ageing as well as in the development of cardiovascular diseases. Accumulation of AGEs contribute to tissue stiffness and organ dysfunction by crosslinking extracellular matrix proteins like collagen. We aimed to assess whether AGE-modified cardiac tissue collagen and AGE related skin autofluorescence may reflect the cardiac function and have a prognostic value for the outcome of coronary artery bypass surgery patients. Therefore, AGE-modifications in collagen from 72 male patients undergoing isolated coronary artery bypass graft (CABG) surgery were analyzed. Collagen fractions were isolated from the right atrial auricle and the residual bypass graft material (saphenous vein) of these patients and quantified by 4-hydroxyproline assay. AGE modifications were determined by the AGE intrinsic fluorescence (excitation 360nm/emission 440nm). The skin autofluorescence (sAF) as a non-invasive parameter was measured using the AGE reader. The non-extractable collagen contained the highest amounts of AGEs and positively correlates with the patients age (p=0.0001), blood glucose level (p=0.002), HbA1c level (p=0.01) and sAF (p=0.008). The right atrial auricle collagen showed significantly more modifications compared to vein graft material of the same patient (p=0,001). Skin autofluorescence positively correlates with AGE content in cardiac tissue (p=0.01) and therefore could be used as a predictor of tissue stiffness in patients with coronary heart disease.

  19. The skin autofluorescence reflects the posttranslational glycation grade of the matrix protein collagen.

    Science.gov (United States)

    Jacobs, Kathleen; Navarrete Santos, Alexander; Simm, Andreas; Silber, Rolf-Edgar; Hofmann, Britt

    2014-10-01

    Advanced glycation end products (AGEs) seem to be involved in ageing as well as in the development of cardiovascular diseases. Accumulation of AGEs contribute to tissue stiffness and organ dysfunction by crosslinking extracellular matrix proteins like collagen. We aimed to assess whether AGE-modified cardiac tissue collagen and AGE related skin autofluorescence may reflect the cardiac function and have a prognostic value for the outcome of coronary artery bypass surgery patients. Therefore, AGE-modifications in collagen from 72 male patients undergoing isolated coronary artery bypass graft (CABG) surgery were analyzed. Collagen fractions were isolated from the right atrial auricle and the residual bypass graft material (saphenous vein) of these patients and quantified by 4-hydroxyproline assay. AGE modifications were determined by the AGE intrinsic fluorescence (excitation 360nm/emission 440nm). The skin autofluorescence (sAF) as a non-invasive parameter was measured using the AGE reader. The non-extractable collagen contained the highest amounts of AGEs and positively correlates with the patients age (p=0.0001), blood glucose level (p=0.002), HbA1c level (p=0.01) and sAF (p=0.008). The right atrial auricle collagen showed significantly more modifications compared to vein graft material of the same patient (p=0,001). Skin autofluorescence positively correlates with AGE content in cardiac tissue (p=0.01) and therefore could be used as a predictor of tissue stiffness in patients with coronary heart disease. PMID:26461346

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

    Science.gov (United States)

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

    2015-12-01

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

  1. 3D printing of composite calcium phosphate and collagen scaffolds for bone regeneration.

    Science.gov (United States)

    Inzana, Jason A; Olvera, Diana; Fuller, Seth M; Kelly, James P; Graeve, Olivia A; Schwarz, Edward M; Kates, Stephen L; Awad, Hani A

    2014-04-01

    Low temperature 3D printing of calcium phosphate scaffolds holds great promise for fabricating synthetic bone graft substitutes with enhanced performance over traditional techniques. Many design parameters, such as the binder solution properties, have yet to be optimized to ensure maximal biocompatibility and osteoconductivity with sufficient mechanical properties. This study tailored the phosphoric acid-based binder solution concentration to 8.75 wt% to maximize cytocompatibility and mechanical strength, with a supplementation of Tween 80 to improve printing. To further enhance the formulation, collagen was dissolved into the binder solution to fabricate collagen-calcium phosphate composites. Reducing the viscosity and surface tension through a physiologic heat treatment and Tween 80, respectively, enabled reliable thermal inkjet printing of the collagen solutions. Supplementing the binder solution with 1-2 wt% collagen significantly improved maximum flexural strength and cell viability. To assess the bone healing performance, we implanted 3D printed scaffolds into a critically sized murine femoral defect for 9 weeks. The implants were confirmed to be osteoconductive, with new bone growth incorporating the degrading scaffold materials. In conclusion, this study demonstrates optimization of material parameters for 3D printed calcium phosphate scaffolds and enhancement of material properties by volumetric collagen incorporation via inkjet printing.

  2. Collagen Fingerprinting: A New Screening Technique for Radiocarbon Dating Ancient Bone.

    Directory of Open Access Journals (Sweden)

    Virginia L Harvey

    Full Text Available Collagen is the dominant organic component of bone and is intimately locked within the hydroxyapatite structure of this ubiquitous biomaterial that dominates archaeological and palaeontological assemblages. Radiocarbon analysis of extracted collagen is one of the most common approaches to dating bone from late Pleistocene or Holocene deposits, but dating is relatively expensive compared to other biochemical techniques. Numerous analytical methods have previously been investigated for the purpose of screening out samples that are unlikely to yield reliable dates including histological analysis, UV-stimulated fluorescence and, most commonly, the measurement of percentage nitrogen (%N and ratio of carbon to nitrogen (C:N. Here we propose the use of collagen fingerprinting (also known as Zooarchaeology by Mass Spectrometry, or ZooMS, when applied to species identification as an alternative screening method for radiocarbon dating, due to its ability to provide information on collagen presence and quality, alongside species identification. The method was tested on a series of sub-fossil bone specimens from cave systems on Cayman Brac (Cayman Islands, chosen due to the observable range in diagenetic alteration, and in particular, the extent of mineralisation. Six (14C dates, of 18 initial attempts, were obtained from remains of extinct hutia, Capromys sp. (Rodentia; Capromyidae, recovered from five distinct caves on Cayman Brac, and ranging from 393 ± 25 to 1588 ± 26 radiocarbon years before present (yr BP. All of the bone samples that yielded radiocarbon dates generated excellent collagen fingerprints, and conversely those that gave poor fingerprints also failed dating. Additionally, two successfully fingerprinted bone samples were screened out from a set of 81. Both subsequently generated (14C dates, demonstrating successful utilisation of ZooMS as an alternative screening mechanism to identify bone samples that are suitable for 1(4C analysis.

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

    Directory of Open Access Journals (Sweden)

    Robert C. Rennert

    2013-01-01

    Full Text Available 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.

  4. Towards Tuning the Mechanical Properties of Three-Dimensional Collagen Scaffolds Using a Coupled Fiber-Matrix Model

    Directory of Open Access Journals (Sweden)

    Shengmao Lin

    2015-08-01

    Full Text Available Scaffold mechanical properties are essential in regulating the microenvironment of three-dimensional cell culture. A coupled fiber-matrix numerical model was developed in this work for predicting the mechanical response of collagen scaffolds subjected to various levels of non-enzymatic glycation and collagen concentrations. The scaffold was simulated by a Voronoi network embedded in a matrix. The computational model was validated using published experimental data. Results indicate that both non-enzymatic glycation-induced matrix stiffening and fiber network density, as regulated by collagen concentration, influence scaffold behavior. The heterogeneous stress patterns of the scaffold were induced by the interfacial mechanics between the collagen fiber network and the matrix. The knowledge obtained in this work could help to fine-tune the mechanical properties of collagen scaffolds for improved tissue regeneration applications.

  5. Mineralized collagen scaffolds induce hMSC osteogenesis and matrix remodeling

    OpenAIRE

    Weisgerber, D.W.; Caliari, S.R.; Harley, B.A.C.

    2015-01-01

    Biomaterials for bone tissue engineering must be able to instruct cell behavior in the presence of the complex biophysical and biomolecular environments encountered in vivo. While soluble supplementation strategies have been identified to enhance osteogenesis, they are subject to significant diffusive loss in vivo or the need for frequent re-addition in vitro. This investigation therefore explored whether biophysical and biochemical properties of a mineralized collagen-GAG scaffold were suffi...

  6. A Novel HA/β-TCP-Collagen Composite Enhanced New Bone Formation for Dental Extraction Socket Preservation in Beagle Dogs

    Directory of Open Access Journals (Sweden)

    Ko-Ning Ho

    2016-03-01

    Full Text Available Past studies in humans have demonstrated horizontal and vertical bone loss after six months following tooth extraction. Many biomaterials have been developed to preserve bone volume after tooth extraction. Type I collagen serves as an excellent delivery system for growth factors and promotes angiogenesis. Calcium phosphate ceramics have also been investigated because their mineral chemistry resembles human bone. The aim of this study was to compare the performance of a novel bioresorbable purified fibrillar collagen and hydroxyapatite/β-tricalcium phosphate (HA/β-TCP ceramic composite versus collagen alone and a bovine xenograft-collagen composite in beagles. Collagen plugs, bovine graft-collagen composite and HA/β-TCP-collagen composite were implanted into the left and right first, second and third mandibular premolars, and the fourth molar was left empty for natural healing. In total, 20 male beagle dogs were used, and quantitative and histological analyses of the extraction ridge was done. The smallest width reduction was 19.09% ± 8.81% with the HA/β-TCP-collagen composite at Week 8, accompanied by new bone formation at Weeks 4 and 8. The HA/β-TCP-collagen composite performed well, as a new osteoconductive and biomimetic composite biomaterial, for socket bone preservation after tooth extraction.

  7. The effects of glucocorticoid on microarchitecture, collagen, mineral and mechanical properties of sheep femur cortical bone

    DEFF Research Database (Denmark)

    Ding, Ming; Danielsen, Carl C; Overgaard, Søren

    treatment. Group 3 was left untreated and served as the controls. All sheep received restricted diet with low calcium and phosphorus. At sacrifice, cortical bone samples from the femur midshaft of sheep were harvested, micro-CT scanned and tested in 3 point bending and in tensile. Bone collagen and mineral......The effects of glucocorticoid on microarchitecture, collagen, mineral and mechanical properties of sheep femur cortical bone – Validation of large animal model for tissue engineering and biomaterial research Ming Ding,1* Carl Christian Danielsen,2 Søren Overgaard1 1Orthopaedic Research Laboratory......, Department of Orthopaedics and Traumatology, Odense University Hospital, Institute of Clinical Research, University of Southern Denmark, Odense C, Denmark 2Department of Connective Tissue Biology, Institute of Anatomy, University of Aarhus, Aarhus C, Denmark Osteopenia in sheep has been successfully induced...

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

    Science.gov (United States)

    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

  9. In vivo study of extracellular matrix coating enhancing fixation of the pedicle screw-bone's interface

    Institute of Scientific and Technical Information of China (English)

    LIU Guo-min; ZHANG Xing-yi; XU Chuan-jie; ZHU Xiao-min; WANG Jun; LIU Yi

    2011-01-01

    Background Based on in vivo research on the effect of the coating of the extracellular matrix composition of pedicle screws on the conduction and induction of bone formation in young sheep,the aim of this study was to investigate the application of coated pedicle screws in sheep with scoliosis whose spines are under constant development.Methods Four groups of pedicle screws were randomly implanted into bilateral L2-L5 pedicles of 2.5- to 3-month-old sheep.A static experiment was performed on one side and a loading test was performed on the other side by implanting connecting rods at the L2-L3 and L4-L5 segments.The changes in the force on the coated screws and the combination of the surface of the coated screws with the surrounding bone in the growth process of young sheep's spines with aging were observed.After 3 months,the lumbar vertebrae with the screws were removed and examined by micro-CT,histological,and biomechanical analyses.Results Under nonloading conditions,there is bone formation around the surfaces of coated screws.The bone forming on the surface of collagen/chondroitin sulfate/hydroxyapatite coating of pedicle screws is the most,the one of the collagen / chondrcitin sulfate coating and hydroxyapatite coating is followed,and no significant difference between the two groups.In terms of the trabecular bone morphology parameters of the region of interest around the surface of the pedicle screws,such as bone mineral content,bone mineral density,tissue mineral content,tissue bone mineral density,bone volume fraction,and connection density,those associated with collagen/chondroitin sulfate/hydroxyapatite coatings are largest and those unassociated with coatings are smallest.Under nonloading conditions,the pullout strength of the collagen/chondroitin sulfate/hydroxyapatite-coated screws was largest,and that of the uncoated screws was minimal (P <0.01).Under loading conditions,the maximum pullout strength of each group of pedicle screws was less than that

  10. The crucial role of collagen-binding integrins in maintaining the mechanical properties of human scleral fibroblasts-seeded collagen matrix

    OpenAIRE

    Hu, Shoulong; Cui, Dongmei; Yang, Xiao; Hu, Jianmin; Wan, Wenjuan; Zeng, Junwen

    2011-01-01

    Purpose The aim of this study was to identify the presence of collagen-binding integrin subunits in human scleral fibroblasts (HSFs) and investigate their actual functions in maintaining the mechanical creep properties of the HSFs-seeded collagen matrix. Methods Primary HSFs were cultured in vitro. Reverse- transcription PCR was used to detect mRNA expression of integrin α1, α2, and β1 subunits in HSFs. In addition, western blot analysis and immunofluorescence were used to detect their protei...

  11. Type II collagen peptide is able to accelerate embryonic chondrocyte differentiation: an association with articular cartilage matrix resorption in osteoarthrosis

    Directory of Open Access Journals (Sweden)

    Elena Vasil'evna Chetina

    2010-01-01

    Conclusion. The effect of CP on gene expression and collagen decomposition activity depends on the morphotype of embryonic chondrocytes. Lack of effect of CP on collagen decomposition activity in both the embryonic hypertrophic chondrocytes and the cartilage explants from OA patients supports the hypothesis that the hypertrophic morphotype is a dominant morphotype of articular chondrocytes in OA. Moreover, collagen decomposition products can be involved in the resorption of matrix in OA and in the maintenance of chronic nature of the pathology.

  12. Effects of fibril- or fixed-collagen on matrix metalloproteinase-1and tissue inhibitor of matrix metalloproteinase-1 production in the human hepatocyte cell line HLE

    Institute of Scientific and Technical Information of China (English)

    Makoto Nakamuta; Kazuhiro Kotoh; Munechika Enjoji; Hajime Nawata

    2005-01-01

    AIM: Matrix metalloproteinase-1 (MMP-1) and tissue inhibitor of matrix metalloproteinase-1 (TIMP-1) are central to the spontaneous resolution of liver fibrosis. The mechanisms involved have been investigated in hepatic steilate cells (ISC), but not in hepatocytes. We investigated the effects of fibril- and fixed-collagen on MMP-1 and TIMP-1 production in hepatocytes, using the HLE cell line.METHODS: Fibril type T and Ⅳ collagen were prepared by HCl digestion of type T and Ⅳ collagen, respectively.For fixed-collagen, culture dishes were coated with fibril type Ⅰ or Ⅳ collagen and fixed by ultraviolet. Type Ⅰcollagenase activity was measured using fluorescein isothiocyanate-labeled type Ⅰ collagen. MMP-1 and TIMP-1 in HLE cells were measured by a one-step sandwich enzyme immunoassay.RESULTS: Both fibril type Ⅰand Ⅳ collagen significantly increased type Ⅰ coilagenase activity about two-fold compared with no fibril collagen. The effects of the fibril collagen were not affected by the coating condition. There was no significant difference in the effects on collagenase activity between cells cultured in medium containing fibril type Ⅰ collagen and those cultured in the presence of type Ⅳ collagen. Both types of fibril collagen significantly increased MMP-1 production, and showed more than 10-fold higher levels of MMP-1 than the control. The enhanced MMP-1 production by fibril collagens was unaffected by the coating condition. By contrast, TIMP-1 production was not changed by the addition of fibril type Ⅰ or Ⅳ collagen,and neither was it affected by the coating conditions.Coating with type Ⅰ collagen significantly suppressed MMP-1production by almost one-tenth compared with no coating.By contrast, lIMP-1 production was not affected by either the absence of a collagen coat or by increasing the concentration of the coating collagen.CONCLUSION: These results indicated that, in HLE cells,fibril- and fixed-collagen have opposite effects on MMP-1

  13. Skin, bone and muscle collagen extraction from the trash fish, leather jacket (Odonus niger) and their characterization.

    Science.gov (United States)

    Muralidharan, Nagarajan; Jeya Shakila, Robinson; Sukumar, Durairaj; Jeyasekaran, G

    2013-12-01

    Acid soluble (ASC) and pepsin soluble (PSC) collagens were extracted from the skin, bone and muscle of a trash fish, leather jacket (Odonus niger) by three different extraction methods. Method I gave 46-50% yield for ASC, Method II gave 49-58% yield for both ASC and PSC and Method III gave 64-71% yield for PSC. The addition of pepsin had increased the yield by 30-45%. The yields of collagen from skin and bone were higher than muscle. SDS-PAGE pattern revealed that skin and bone collagen as Type I collagen with a typical (α1)2α2 chains and muscle collagen as Type V collagen with a typical α1α3α2 chains. Td values of bone and muscle collagen were high (30-32 °C) compared to skin collagen (27-28 °C). The higher imino acids (190 residues/1,000 residues) were found responsible for the higher Td values. The trash fish, leather jacket can therefore be exploited effectively for collagen as it has got good thermal properties for pharmaceutical and biomedical applications.

  14. Clinical evaluation of a collagen matrix to enhance the width of keratinized gingiva around dental implants

    OpenAIRE

    Lee, Kang-Ho; Kim, Byung-Ock; Jang, Hyun-Seon

    2010-01-01

    Purpose The purpose of this study was to evaluate the effect of collagen matrix with apically positioned flap (APF) on the width of keratinized gingiva, comparing to the results of APF only and APF combined with free gingival graft (FGG) at the second implant surgery. Methods Nine patients were selected from those who had received treatments at the Department of Periodontics, Chosun University Dental Hospital, Gwangju, Korea. We performed APF, APF combined with FGG, and APF combined with coll...

  15. Reconstruction of focal cartilage defects in the talus with miniarthrotomy and collagen matrix

    OpenAIRE

    Walther, M.; Altenberger, S; Kriegelstein, S; Volkering, C; Röser, A.

    2014-01-01

    Surgical principal and objective Treatment of focal cartilage defects (traumatic or osteochondrosis dissecans) of the talus using a collagen matrix. The goal is to stabilize the superclot formed after microfracturing to accommodate cartilage repair. The procedure can be carried out via miniarthrotomy, without medial malleolus osteotomy. Indications International Cartilage Repair Society (ICRS) grade III and IV focal cartilage defects of the talus > 1.5 cm2. Contraindications Generalized osteo...

  16. Skin, bone and muscle collagen extraction from the trash fish, leather jacket (Odonus niger) and their characterization

    OpenAIRE

    Muralidharan, Nagarajan; Jeya Shakila, Robinson; Sukumar, Durairaj; Jeyasekaran, G.

    2011-01-01

    Acid soluble (ASC) and pepsin soluble (PSC) collagens were extracted from the skin, bone and muscle of a trash fish, leather jacket (Odonus niger) by three different extraction methods. Method I gave 46–50% yield for ASC, Method II gave 49–58% yield for both ASC and PSC and Method III gave 64–71% yield for PSC. The addition of pepsin had increased the yield by 30–45%. The yields of collagen from skin and bone were higher than muscle. SDS-PAGE pattern revealed that skin and bone collagen as Ty...

  17. Innovative Biomaterials Based on Collagen-Hydroxyapatite and Doxycycline for Bone Regeneration

    Directory of Open Access Journals (Sweden)

    Narcisa Mederle

    2016-01-01

    Full Text Available Bone regeneration is a serious challenge in orthopedic applications because of bone infections increase, tumor developing, and bone loss due to trauma. In this context, the aim of our study was to develop innovative biomaterials based on collagen and hydroxyapatite (25, 50, and 75% which mimic bone composition and prevent or treat infections due to doxycycline content. The biomaterials were obtained by freeze-drying in spongious forms and were characterized by water uptake capacity and microscopy. The in vitro release of doxycycline was also determined and established by non-Fickian drug transport mechanism. Among the studied biomaterials, the most suitable one to easily deliver the drug and mimic bone structure, having compact structure and lower capacity to uptake water, was the one with 75% hydroxyapatite and being cross-linked.

  18. Exercise and Regulation of Bone and Collagen Tissue Biology

    DEFF Research Database (Denmark)

    Kjær, Michael; Jørgensen, Niklas Rye; Heinemeier, Katja Maria;

    2015-01-01

    The musculoskeletal system and its connective tissue include the intramuscular connective tissue, the myotendinous junction, the tendon, the joints with their cartilage and ligaments, and the bone; they all together play a crucial role in maintaining the architecture of the skeletal muscle...

  19. Mechanical Properties and Cytocompatibility Improvement of Vertebroplasty PMMA Bone Cements by Incorporating Mineralized Collagen

    Directory of Open Access Journals (Sweden)

    Hong-Jiang Jiang

    2015-05-01

    Full Text Available Polymethyl methacrylate (PMMA bone cement is a commonly used bone adhesive and filling material in percutaneous vertebroplasty and percutaneous kyphoplasty surgeries. However, PMMA bone cements have been reported to cause some severe complications, such as secondary fracture of adjacent vertebral bodies, and loosening or even dislodgement of the set PMMA bone cement, due to the over-high elastic modulus and poor osteointegration ability of the PMMA. In this study, mineralized collagen (MC with biomimetic microstructure and good osteogenic activity was added to commercially available PMMA bone cement products, in order to improve both the mechanical properties and the cytocompatibility. As the compressive strength of the modified bone cements remained well, the compressive elastic modulus could be significantly down-regulated by the MC, so as to reduce the pressure on the adjacent vertebral bodies. Meanwhile, the adhesion and proliferation of pre-osteoblasts on the modified bone cements were improved compared with cells on those unmodified, such result is beneficial for a good osteointegration formation between the bone cement and the host bone tissue in clinical applications. Moreover, the modification of the PMMA bone cements by adding MC did not significantly influence the injectability and processing times of the cement.

  20. Autologous bone graft versus demineralized bone matrix in internal fixation of ununited long bones

    Directory of Open Access Journals (Sweden)

    Rubenbauer Bianka

    2009-12-01

    Full Text Available Abstract Background Non-unions are severe complications in orthopaedic trauma care and occur in 10% of all fractures. The golden standard for the treatment of ununited fractures includes open reduction and internal fixation (ORIF as well as augmentation with autologous-bone-grafting. However, there is morbidity associated with the bone-graft donor site and some patients offer limited quantity or quality of autologous-bone graft material. Since allogene bone-grafts are introduced on the market, this comparative study aims to evaluate healing characteristics of ununited bones treated with ORIF combined with either iliac-crest-autologous-bone-grafting (ICABG or demineralized-bone-matrix (DBM. Methods and results From 2000 to 2006 out of sixty-two consecutive patients with non-unions presenting at our Level I Trauma Center, twenty patients had ununited diaphyseal fractures of long bones and were treated by ORIF combined either by ICABG- (n = 10 or DBM-augmentation (n = 10. At the time of index-operation, patients of the DBM-group had a higher level of comorbidity (ASA-value: p = 0.014. Mean duration of follow-up was 56.6 months (ICABG-group and 41.2 months (DBM-group. All patients were clinically and radiographically assessed and adverse effects related to bone grafting were documented. The results showed that two non-unions augmented with ICABG failed osseous healing (20% whereas all non-unions grafted by DBM showed successful consolidation during the first year after the index operation (p = 0.146. No early complications were documented in both groups but two patients of the ICABG-group suffered long-term problems at the donor site (20% (p = 0.146. Pain intensity were comparable in both groups (p = 0.326. However, patients treated with DBM were more satisfied with the surgical procedure (p = 0.031. Conclusion With the use of DBM, the costs for augmentation of the non-union-site are more expensive compared to ICABG (calculated difference: 160

  1. The effect of stromelysin-1 (MMP-3) on non-collagenous extracellular matrix proteins of demineralized dentin and the adhesive properties of restorative resins.

    Science.gov (United States)

    Boukpessi, T; Menashi, S; Camoin, L; Tencate, J M; Goldberg, M; Chaussain-Miller, C

    2008-11-01

    Dentin non-collagenous matrix components (NCPs) are structural proteins involved in the formation, the architecture and the mineralization of the extracellular matrix (ECM). We investigated here how recombinant metalloproteinase stromelysin-1, also termed MMP-3, initiates the release of ECM molecules from artificially demineralized human dentin. Analysis of the supernatants by Western blotting reveals that MMP-3 extracts PGs (decorin, biglycan), and also a series of phosphorylated proteins: dentin sialoprotein (DSP), osteopontin (OPN), bone sialoprotein (BSP) and MEPE, but neither dentin matrix protein-1 (DMP1), another member of the SIBLING family, nor osteocalcin (OC), a non-phosphorylated matrix molecule. After treatment of dentin surfaces by MMP-3, scanning electron microscope (SEM) examination of resin replica shows an increased penetration of the resin into the dentin tubules when compared to surfaces only treated by demineralizing solutions. This preclinical investigation suggests that MMP-3 may be used to improve the adhesive properties of restorative materials.

  2. Chitosan-collagen/organomontmorillonite scaffold for bone tissue engineering

    Science.gov (United States)

    Cao, Xianshuo; Wang, Jun; Liu, Min; Chen, Yong; Cao, Yang; Yu, Xiaolong

    2015-12-01

    A novel composite scaffold based on chitosan-collagen/organomontmorillonite (CS-COL/OMMT) was prepared to improve swelling ratio, biodegradation ratio, biomineralization and mechanical properties for use in tissue engineering applications. In order to expend the basal spacing, montmorillonite (MMT) was modified with sodium dodecyl sulfate (SDS) and was characterized by XRD, TGA and FTIR. The results indicated that the anionic surfactants entered into interlayer of MMT and the basal spacing of MMT was expanded to 3.85 nm. The prepared composite scaffolds were characterized by FTIR, XRD and SEM. The swelling ratio, biodegradation ratio and mechanical properties of composite scaffolds were also studied. The results demonstrated that the scaffold decreased swelling ratio, degradation ratio and improved mechanical and biomineralization properties because of OMMT.

  3. The crucial role of collagen-binding integrins in maintaining the mechanical properties of human scleral fibroblasts-seeded collagen matrix

    Science.gov (United States)

    Hu, Shoulong; Cui, Dongmei; Yang, Xiao; Hu, Jianmin; Wan, Wenjuan

    2011-01-01

    Purpose The aim of this study was to identify the presence of collagen-binding integrin subunits in human scleral fibroblasts (HSFs) and investigate their actual functions in maintaining the mechanical creep properties of the HSFs-seeded collagen matrix. Methods Primary HSFs were cultured in vitro. Reverse- transcription PCR was used to detect mRNA expression of integrin α1, α2, and β1 subunits in HSFs. In addition, western blot analysis and immunofluorescence were used to detect their protein in HSFs. Monoclonal antibodies were applied directly against the extracellular domains of integrin subunits in HSFs cultured in the three-dimensional collagen gels to block the interaction between HSFs and the extracellular collagen matrix. The effects of anti-integrin antibodies on HSFs morphology in collagen gel were observed. The effects of the added antibodies on fibroblast-mediated collagen gels’ contraction were evaluated. Furthermore, the changes in mechanical creep properties of collagen gel were measured by a biomechanics test instrument. Results The mRNA and protein expressions of collagen-binding integrin α1, α2, and β1 subunits were present in HSFs. The elongated bipolar cells converted to spherical shapes after 6 h after the addition of integrin α1β1 and α2β1 antibody. The blocking of integrin α1β1 and α2β1 subunits noticeably decreased the contraction in the collagen gels. In addition, all samples were subjected to a constantly applied load of 0.03 N for 600 s. The blocking of integrin α1β1 and α2β1 subunits also induced increases in the values of final extension, creep extension, and creep rate, compared to those of the controls (p0.05). Conclusions Our findings suggested that HSF integrin α1β1 and α2β1 participated in maintaining the mechanical creep properties of the HSFs-seeded collagen matrix. Furthermore, integrin α2β1 might play a more crucial role in maintaining the mechanical creep properties of the collagen matrix than does

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

    OpenAIRE

    Kim, Ji-Beom; Lee, Dong Yeon; 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 u...

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

    Science.gov (United States)

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

    2010-08-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Yang Bo; Yin Zhanhai; Cao Junling; Shi Zhongli; Zhang Zengtie; Liu Fuqiang [College of Medicine, Xi' an Jiaotong University, Yanta West Road, No 76, Yanta District, Xi' an, Shaanxi Province 710061 (China); Song Hongxing [Department of Orthopedics, Xuanwu Hospital, Capital Medical University, Beijing 100053 (China); Caterson, Bruce, E-mail: caojl@mail.xjtu.edu.c [Connective Tissue Biology Laboratories, Cardiff School of Biosciences, Cardiff University, Biomedical Building, Museum Avenue, Cardiff, CF10 3US (United Kingdom)

    2010-08-01

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

  7. Matrix metalloproteinase-9-mediated type III collagen degradation as a novel serological biochemical marker for liver fibrogenesis

    DEFF Research Database (Denmark)

    Veidal, Sanne S; Vassiliadis, Efstathios; Barascuk, Natasha;

    2010-01-01

    During fibrogenesis in the liver, in which excessive remodelling of the extracellular matrix (ECM) occurs, both the quantity of type III collagen (CO3) and levels of matrix metalloproteinases (MMPs), including MMP-9, increase significantly. MMPs play major roles in ECM remodelling, via their...... activity in the proteolytic degradation of extracellular macromolecules such as collagens, resulting in the generation of specific cleavage fragments. These neo-epitopes may be used as markers of fibrosis....

  8. Combined oral administration of bovine collagen peptides with calcium citrate inhibits bone loss in ovariectomized rats.

    Directory of Open Access Journals (Sweden)

    JunLi Liu

    Full Text Available Collagen peptides (CPs and calcium citrate are commonly used as bone health supplements for treating osteoporosis. However, it remains unknown whether the combination of oral bovine CPs with calcium citrate is more effective than administration of either agent alone.Forty 12-week-old Sprague-Dawley rats were randomly divided into five groups (n = 8 for once-daily intragastric administration of different treatments for 3 months at 3 months after ovariectomy (OVX as follows: sham + vehicle; OVX + vehicle; OVX + 750 mg/kg CP; OVX + CP-calcium citrate (75 mg/kg; OVX + calcium citrate (75 mg/kg. After euthanasia, the femurs were removed and analyzed by dual energy X-ray absorptiometry and micro-computed tomography, and serum samples were analyzed for bone metabolic markers.OVX rats supplemented with CPs or CP-calcium citrate showed osteoprotective effects, with reductions in the OVX-induced decreases in their femoral bone mineral density. Moreover, CP-calcium citrate prevented trabecular bone loss, improved the microarchitecture of the distal femur, and significantly inhibited bone loss with increased bone volume, connectivity density, and trabecular number compared with OVX control rats. CP or CP-calcium citrate administration significantly increased serum procollagen type I N-terminal propeptide levels and reduced serum bone-specific alkaline phosphatase, osteocalcin, and C-telopeptide of type I collagen levels.Our data indicate that combined oral administration of bovine CPs with calcium citrate inhibits bone loss in OVX rats. The present findings suggest that combined oral administration of bovine CPs with calcium citrate is a promising alternative for reducing bone loss in osteopenic postmenopausal women.

  9. MG63 osteoblast-like cells exhibit different behavior when grown on electrospun collagen matrix versus electrospun gelatin matrix.

    Directory of Open Access Journals (Sweden)

    Shiao-Wen Tsai

    Full Text Available Electrospinning is a simple and efficient method of fabricating a non-woven polymeric nanofiber matrix. However, using fluorinated alcohols as a solvent for the electrospinning of proteins often results in protein denaturation. TEM and circular dichroism analysis indicated a massive loss of triple-helical collagen from an electrospun collagen (EC matrix, and the random coils were similar to those found in gelatin. Nevertheless, from mechanical testing we found the Young's modulus and ultimate tensile stresses of EC matrices were significantly higher than electrospun gelatin (EG matrices because matrix stiffness can affect many cell behaviors such as cell adhesion, proliferation and differentiation. We hypothesize that the difference of matrix stiffness between EC and EG will affect intracellular signaling through the mechano-transducers Rho kinase (ROCK and focal adhesion kinase (FAK and subsequently regulates the osteogenic phenotype of MG63 osteoblast-like cells. From the results, we found there was no significant difference between the EC and EG matrices with respect to either cell attachment or proliferation rate. However, the gene expression levels of OPN, type I collagen, ALP, and OCN were significantly higher in MG63 osteoblast-like cells grown on the EC than in those grown on the EG. In addition, the phosphorylation levels of Y397-FAK, ERK1/2, BSP, and OPN proteins, as well as ALP activity, were also higher on the EC than on the EG. We further inhibited ROCK activation with Y27632 during differentiation to investigate its effects on matrix-mediated osteogenic differentiation. Results showed the extent of mineralization was decreased with inhibition after induction. Moreover, there is no significant difference between EC and EG. From the results of the protein levels of phosphorylated Y397-FAK, ERK1/2, BSP and OPN, ALP activity and mineral deposition, we speculate that the mechanism that influences the osteogenic differentiation of MG63

  10. Human osteoblast-like cells respond to mechanical strain with increased bone matrix protein production independent of hormonal regulation

    Science.gov (United States)

    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.

  11. Host-derived Loss of Dentin Matrix Stiffness Associated with Solubilization of Collagen

    Science.gov (United States)

    Carrilho, Marcela R.; Tay, Franklin R.; Donnelly, Adam M.; Agee, Kelli A.; Tjäderhane, Leo; Mazzoni, Annalisa; Breschi, Lorenzo; Foulger, Stephen; Pashley, David H.

    2009-01-01

    Matrix metalloproteinases (MMPs) bound to dentin matrices are activated during adhesive bonding procedures and are thought to contribute to the progressive degradation of resin-dentin bonds over time. The purpose of this study was to evaluate the changes in mechanical, biochemical and structural properties of demineralized dentin treated with or without chlorhexidine (CHX), a known MMP-inhibitor. After demineralizing dentin beams in EDTA or phosphoric acid (PA), the baseline modulus of elasticity (E) of each beam was measured by 3-point flexure. Specimens were pretreated with water (control) or with 2% CHX (experimental) and then incubated in artificial saliva (AS) at 37°C for 4 weeks. The E of each specimen was remeasured weekly and, the media was analyzed for solubilized dentin collagen at first and fourth week of incubation. Some specimens were processed for electron microscopy (TEM) immediately after demineralization and after 4 weeks of incubation. In EDTA and PA-demineralized specimens, the E of the control specimens fell (p<0.05) after incubation in AS, while there were no changes in E in the CHX-pretreated specimens over time. More collagen was solubilized from PA-demineralized controls (p<0.05) than from EDTA-demineralized matrices after 1 or 4 weeks. Less collagen (p<0.05) was solubilized from CHX-pretreated specimens demineralized in EDTA compared to PA. TEM examination of control beams revealed that prolonged demineralization of dentin in 10% PA (12 h) did not denature the collagen fibrils. PMID:19090493

  12. Pressure therapy upregulates matrix metalloproteinase expression and downregulates collagen expression in hypertrophic scar tissue

    Institute of Scientific and Technical Information of China (English)

    HUANG Dong; SHEN Kuan-hong; WANG Hong-gang

    2013-01-01

    Background Pressure therapy improves hypertrophic scar healing,but the mechanisms for this process are not well understood.We sought to investigate the differential expression of matrix metalloproteinases (Mmps) and collagen in posttraumatic hypertrophic scar tissue with mechanical pressure and delineate the molecular mechanisms of pressure therapy for hypertrophic scars.Methods Fibroblast lines of normal skin and scar tissue were established and a mechanical pressure system was devised to simulate pressure therapy.Reverse transcription-polymerase chain reaction (RT-PCR) and Western blotting assays were used to compare differences in the mRNA and protein expression of Mmps and collagen in scar fibroblasts before and after pressure therapy.Results The expression differed between the hypertrophic scar cell line and the normal cell line.RT-PCR assays showed that Collagen I,highly expressed in the hypertrophic scar cell line,decreased significantly after pressure therapy.Mmp2,Mmp9,and Mmp12 expression in the hypertrophic scar tissue increased significantly after pressure therapy (P <0.05).Western blotting assays further revealed that Mmp9 and Mmp12 expression increased significantly in the hypertrophic scar tissue after pressure therapy (P <0.05) but not Mmp2 expression (P >0.05).Conclusion Mechanical pressure induces degradation of Collagen Ⅰ in hypertrophic scar tissue by affecting the expression of Mmp9 and Mmp12.

  13. Bone induction by composites of bioresorbable carriers and demineralized bone in rats: a comparative study of fibrin-collagen paste, fibrin sealant, and polyorthoester with gentamicin

    DEFF Research Database (Denmark)

    Pinholt, E M; Solheim, E; Bang, G;

    1992-01-01

    fibrin-collagen paste and fibrin sealant inhibited bone induction and produced a chronic inflammation; part of the fibrin-collagen paste was still present at 4 weeks. Polyorthoester with gentamicin was almost completely absorbed, induced minimal tissue reaction, and did not inhibit osteoinduction....

  14. Aging and the cardiac collagen matrix: Novel mediators of fibrotic remodelling.

    Science.gov (United States)

    Horn, Margaux A; Trafford, Andrew W

    2016-04-01

    Cardiovascular disease is a leading cause of death worldwide and there is a pressing need for new therapeutic strategies to treat such conditions. The risk of developing cardiovascular disease increases dramatically with age, yet the majority of experimental research is executed using young animals. The cardiac extracellular matrix (ECM), consisting predominantly of fibrillar collagen, preserves myocardial integrity, provides a means of force transmission and supports myocyte geometry. Disruptions to the finely balanced control of collagen synthesis, post-synthetic deposition, post-translational modification and degradation may have detrimental effects on myocardial functionality. It is now well established that the aged heart is characterized by fibrotic remodelling, but the mechanisms responsible for this are incompletely understood. Furthermore, studies using aged animal models suggest that interstitial remodelling with disease may be age-dependent. Thus with the identification of new therapeutic strategies targeting fibrotic remodelling, it may be necessary to consider age-dependent mechanisms. In this review, we discuss remodelling of the cardiac collagen matrix as a function of age, whilst highlighting potential novel mediators of age-dependent fibrotic pathways. PMID:26578393

  15. The endogenous fluorescence of fibroblast in collagen gels as indicator of stiffness of the extracellular matrix

    Science.gov (United States)

    Padilla-Martinez, J. P.; Ortega-Martinez, A.; Franco, W.

    2016-03-01

    The stiffness or rigidity of the extracellular matrix (ECM) regulates cell response. Established mechanical tests to measure stiffness, such as indentation and tensile tests, are invasive and destructive to the sample. Endogenous or native molecules to cells and ECM components, like tryptophan and cross-links of collagen, display fluorescence upon irradiation with ultraviolet light. Most likely, the concentration of these endogenous fluorophores changes as the stiffness of the ECM changes. In this work we investigate the endogenous fluorescence of collagen gels containing fibroblasts as a non-invasive non-destructive method to measure stiffness of the ECM. Human fibroblast cells were cultured in three-dimensional gels of type I collagen (50,000 cells/ml). This construct is a simple model of tissue contraction. During contraction, changes in the excitation-emission matrix (a fluorescence map in the 240-520/290-530 nm range) of constructs were measured with a spectrofluoremeter, and changes in stiffness were measured with a standard indentation test over 16 days. Results show that a progressive increase in fluorescence of the 290/340 nm excitation-emission pair correlates with a progressive increase in stiffness (r=0.9, α=0.5). The fluorescence of this excitation-emission pair is ascribed to tryptophan and variations in the fluorescence of this pair correlate with cellular proliferation. In this tissue model, the endogenous functional fluorescence of proliferating fibroblast cells is a biomechanical marker of stiffness of the ECM.

  16. Markers of type I collagen degradation and synthesis in the monitoring of treatment response in bone metastases from breast carcinoma.

    OpenAIRE

    Blomqvist, C; Risteli, L; Risteli, J.; Virkkunen, P.; Sarna, S.; Elomaa, I.

    1996-01-01

    Thirty-six patients with bone metastases included in a trial of supportive calcitonin on the treatment response to systemic therapy were monitored by conventional radiography, conventional indicators of bone metabolism [alkaline phosphatase (AP), osteocalcin (gla), urinary hydroxyproline excretion (OHP), urinary calcium (uCa), serum calcium (sCa)] and collagen metabolites (ICTP, the pyridinoline cross-linked carboxy-terminal telopeptide of type I collagen; PICP, the carboxy-terminal propeptid...

  17. Recombinant human-like collagen directed growth of hydroxyapatite nanocrystals

    Science.gov (United States)

    Zhai, Y.; Cui, F. Z.

    2006-05-01

    Bones are biocomposites with hierarchical structure that require controlled mineral deposition during their self-assembly to form tissues with unique mechanical properties. Type I collagen proteins, acidic extracellular matrix proteins, play a critical role in mineral formation and many researches on artificial bones have been made inspired by nature using type I collagen derived from animal tissues. Here we report that recombinant human-like type I collagen, an acidic protein, can direct growth of hydroxyapatite (HA) nanocrystals in vitro in the form of self-assembly of nano-fibrils of mineralized collagen resembling extracellular matrix. The mineralized collagen fibrils aligned parallel to each other to form mineralized collagen fibers. HA nanocrystals grew on the surface of these collagen fibrils with the c-axis of nanocrystals of HA orienting along the longitudinal axis of the fibrils. These artificial analogs of bone have a potential clinical application in bone repair.

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

    Science.gov (United States)

    Kotha, S P; Guzelsu, N

    2007-01-01

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

  19. Enigmatic insight into collagen.

    Science.gov (United States)

    Deshmukh, Shrutal Narendra; Dive, Alka M; Moharil, Rohit; Munde, Prashant

    2016-01-01

    Collagen is a unique, triple helical molecule which forms the major part of extracellular matrix. It is the most abundant protein in the human body, representing 30% of its dry weight. It is the fibrous structural protein that makes up the white fibers (collagen fibers) of skin, tendons, bones, cartilage and all other connective tissues. Collagens are not only essential for the mechanical resistance and resilience of multicellular organisms, but are also signaling molecules defining cellular shape and behavior. The human body has at least 16 types of collagen, but the most prominent types are I, II and III. Collagens are produced by several cell types and are distinguishable by their molecular compositions, morphologic characteristics, distribution, functions and pathogenesis. This is the major fibrous glycoprotein present in the extracellular matrix and in connective tissue and helps in maintaining the structural integrity of these tissues. It has a triple helical structure. Various studies have proved that mutations that modify folding of the triple helix result in identifiable genetic disorders. Collagen diseases share certain similarities with autoimmune diseases, because autoantibodies specific to each collagen disease are produced. Therefore, this review highlights the role of collagen in normal health and also the disorders associated with structural and functional defects in collagen. PMID:27601823

  20. Iron nanoparticles from blood coated with collagen as a matrix for synthesis of nanohydroxyapatite

    Indian Academy of Sciences (India)

    M Chamundeeswari; B Santhosh Kumar; T Muthukumar; L Muthuraman; K Purna Sai; T P Sastry

    2013-12-01

    A simple wet precipitation technique was used to prepare nanobiocomposite containing iron nanoparticles coated with collagen. This nanobiocomposite was used as matrix for the synthesis of nanohydroxyapatite. The physicochemical characteristic studies of the nanohydroxyapatite thus formed were carried out using fourier transform infrared spectroscopy, transmission electron microscopy, scanning electron microscopy, energydispersive X-ray spectroscopy and X-ray diffraction technique to confirm the formation of hydroxyapatite on iron nanoparticle–collagen complex. The results of the above studies supported the formation of iron nanoparticle–collagen–hydroxyapatite composite. The biological studies such as biocompatibility and hemocompatibility were carried out for nanohydroxyapatite using different cell lines and blood sample. The results of biocompatibility and hemolytic assay revealed that the prepared nanobiocomposite was 100 % biocompatible and hemocompatible. This nanobiocomposite may be used for biomedical application such as injectables for targeted delivery and as scaffold for tissue engineering.

  1. Bone induction by composite of bioerodible polyorthoester and deminiralized bone matrix in rats

    Energy Technology Data Exchange (ETDEWEB)

    Pinholt, E.M.; Solheim, E. (Institute for Surgical Research, Rikshospitalet, University of Oslo (Norway)); Bang, G. (Department of Oral Pathology and Forensic Odontology, University of Bergen (Norway)); Sudmann, E. (Hagavik Orthopedic Hospital, University of Bergen (Norway))

    1991-01-01

    A composite of a local, sustained, drug-release system, Alzamer bioerodible polyorthoester, and demineralized bone-matrix (DBM) particles implanted in the abdominal muscle of 89 Wistar rats induced cartilage and bone formation at the same rate as DBM when evaluated histologically and by {sup 85}Sr uptake. The composite implant was technically easier to use than DBM alone. (author).

  2. Mutations in the collagen XII gene define a new form of extracellular matrix-related myopathy.

    Science.gov (United States)

    Hicks, Debbie; Farsani, Golara Torabi; Laval, Steven; Collins, James; Sarkozy, Anna; Martoni, Elena; Shah, Ashoke; Zou, Yaqun; Koch, Manuel; Bönnemann, Carsten G; Roberts, Mark; Lochmüller, Hanns; Bushby, Kate; Straub, Volker

    2014-05-01

    Bethlem myopathy (BM) [MIM 158810] is a slowly progressive muscle disease characterized by contractures and proximal weakness, which can be caused by mutations in one of the collagen VI genes (COL6A1, COL6A2 and COL6A3). However, there may be additional causal genes to identify as in ∼50% of BM cases no mutations in the COL6 genes are identified. In a cohort of -24 patients with a BM-like phenotype, we first sequenced 12 candidate genes based on their function, including genes for known binding partners of collagen VI, and those enzymes involved in its correct post-translational modification, assembly and secretion. Proceeding to whole-exome sequencing (WES), we identified mutations in the COL12A1 gene, a member of the FACIT collagens (fibril-associated collagens with interrupted triple helices) in five individuals from two families. Both families showed dominant inheritance with a clinical phenotype resembling classical BM. Family 1 had a single-base substitution that led to the replacement of one glycine residue in the triple-helical domain, breaking the Gly-X-Y repeating pattern, and Family 2 had a missense mutation, which created a mutant protein with an unpaired cysteine residue. Abnormality at the protein level was confirmed in both families by the intracellular retention of collagen XII in patient dermal fibroblasts. The mutation in Family 2 leads to the up-regulation of genes associated with the unfolded protein response (UPR) pathway and swollen, dysmorphic rough-ER. We conclude that the spectrum of causative genes in extracellular matrix (ECM)-related myopathies be extended to include COL12A1. PMID:24334769

  3. Degradability of injectable calcium sulfate/mineralized collagen-based bone repair material and its effect on bone tissue regeneration

    International Nuclear Information System (INIS)

    The nHAC/CSH composite is an injectable bone repair material with controllable injectability and self-setting properties prepared by introducing calcium sulfate hemihydrate (CSH) into mineralized collagen (nHAC). When mixed with water, the nHAC/CSH composites can be transformed into mineralized collagen/calcium sulfate dihydrate (nHAC/CSD) composites. The nHAC/CSD composites have good biocompatibility and osteogenic capability. Considering that the degradation behavior of bone repair material is another important factor for its clinical applications, the degradability of nHAC/CSD composites was studied. The results showed that the degradation ratio of the nHAC/CSD composites with lower nHAC content increased with the L/S ratio increase of injectable materials, but the variety of L/S ratio had no significant effect on the degradation ratio of the nHAC/CSD composites with higher nHAC content. Increasing nHAC content in the composites could slow down the degradation of nHAC/CSD composite. Setting accelerator had no significant effect on the degradability of nHAC/CSD composites. In vivo histological analysis suggests that the degradation rate of materials can match the growth rate of new mandibular bone tissues in the implanted site of rabbit. The regulable degradability of materials resulting from the special prescriptions of injectable nHAC/CSH composites will further improve the workability of nHAC/CSD composites. - Highlights: • The nHAC/CSH composite can be as an injectable bone repair material. • The L/S ratio and nHAC content have a significant effect on material degradability. • The degradability of bone materials can be regulated to match tissue repair. • The regulable degradability will further improve the workability of bone materials

  4. Degradability of injectable calcium sulfate/mineralized collagen-based bone repair material and its effect on bone tissue regeneration

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Zonggang, E-mail: chenzg@sdu.edu.cn [National Glycoengineering Research Center, Shandong University, Jinan 250100 (China); Department of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China); Kang, Lingzhi [National Glycoengineering Research Center, Shandong University, Jinan 250100 (China); Meng, Qing-Yuan [Department of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China); Liu, Huanye [Department of Prosthodontics, School of Stomatology, China Medical University, Shenyang 110001 (China); Wang, Zhaoliang [Jinan Military General Hospital of PLA, Jinan 250031 (China); Guo, Zhongwu, E-mail: zwguo@sdu.edu.cn [National Glycoengineering Research Center, Shandong University, Jinan 250100 (China); Cui, Fu-Zhai, E-mail: cuifz@mail.tsinghua.edu.cn [Department of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China)

    2014-12-01

    The nHAC/CSH composite is an injectable bone repair material with controllable injectability and self-setting properties prepared by introducing calcium sulfate hemihydrate (CSH) into mineralized collagen (nHAC). When mixed with water, the nHAC/CSH composites can be transformed into mineralized collagen/calcium sulfate dihydrate (nHAC/CSD) composites. The nHAC/CSD composites have good biocompatibility and osteogenic capability. Considering that the degradation behavior of bone repair material is another important factor for its clinical applications, the degradability of nHAC/CSD composites was studied. The results showed that the degradation ratio of the nHAC/CSD composites with lower nHAC content increased with the L/S ratio increase of injectable materials, but the variety of L/S ratio had no significant effect on the degradation ratio of the nHAC/CSD composites with higher nHAC content. Increasing nHAC content in the composites could slow down the degradation of nHAC/CSD composite. Setting accelerator had no significant effect on the degradability of nHAC/CSD composites. In vivo histological analysis suggests that the degradation rate of materials can match the growth rate of new mandibular bone tissues in the implanted site of rabbit. The regulable degradability of materials resulting from the special prescriptions of injectable nHAC/CSH composites will further improve the workability of nHAC/CSD composites. - Highlights: • The nHAC/CSH composite can be as an injectable bone repair material. • The L/S ratio and nHAC content have a significant effect on material degradability. • The degradability of bone materials can be regulated to match tissue repair. • The regulable degradability will further improve the workability of bone materials.

  5. Comparison of growth-induced resorption and denervation-induced resorption on the release of [3H]tetracycline, 45calcium, and [3H]collagen from whole bones of growing rats

    International Nuclear Information System (INIS)

    The major effect of immobilization during growth is a smaller bone mass induced by either an increased bone resorption or a decreased bone formation. Using a method of analyzing radioisotopic loss of [3H]tetracycline and [3H]collagen from bone prelabeled in vivo, we compared the amount of bone resorption due to immobilization with bone resorption induced by growth. One hind limb was denervated in growing male rats, 6 weeks of age, that had been chronically prelabeled with [3H]tetracycline, 45calcium, and [3H]proline. The total radioactivity of the whole femur and tibia/fibula from the denervated limb was compared with that from bones of the control limb at 0, 1, 2, 4, and 8 weeks after denervation. The effect of growth on bone formation was measured by net increases in bone length, volume, and mass of matrix and mineral. Experimental bones had a significantly smaller volume and mass. Bone resorption was much greater during growth modeling than during denervation. The additional bone resorption induced by denervation was a small fraction (one-fourth) of the resorption induced by growth. Denervation during growth resulted in less bone being formed due to a smaller gain in matrix and mineral mass as a result of a reduction in bone formation

  6. Development of Collagen/Demineralized Bone Powder Scaffolds and Periosteum-Derived Cells for Bone Tissue Engineering Application

    Directory of Open Access Journals (Sweden)

    Wilairat Leeanansaksiri

    2013-01-01

    Full Text Available The aim of this study was to investigate physical and biological properties of collagen (COL and demineralized bone powder (DBP scaffolds for bone tissue engineering. DBP was prepared and divided into three groups, based on various particle sizes: 75–125 µm, 125–250 µm, and 250–500 µm. DBP was homogeneously mixed with type I collagen and three-dimensional scaffolds were constructed, applying chemical crosslinking and lyophilization. Upon culture with human periosteum-derived cells (PD cells, osteogenic differentiation of PD cells was investigated using alkaline phosphatase (ALP activity and calcium assay kits. The physical properties of the COL/DBP scaffolds were obviously different from COL scaffolds, irrespective of the size of DBP. In addition, PD cells cultured with COL scaffolds showed significantly higher cell adhesion and proliferation than those with COL/DBP scaffolds. In contrast, COL/DBP scaffolds exhibited greater osteoinductive potential than COL scaffolds. The PD cells with COL/DBP scaffolds possessed higher ALP activity than those with COL scaffolds. PD cells cultured with COL/DBP scaffolds with 250–500 mm particle size yielded the maximum calcium deposition. In conclusion, PD cells cultured on the scaffolds could exhibit osteoinductive potential. The composite scaffold of COL/DBP with 250–500 mm particle size could be considered a potential bone tissue engineering implant.

  7. Compositional and in Vitro Evaluation of Nonwoven Type I Collagen/Poly-dl-lactic Acid Scaffolds for Bone Regeneration

    CERN Document Server

    Qiao, Xiangchen; Yang, Xuebin; Tronci, Giuseppe; Wood, David J

    2015-01-01

    Poly-dl-lactic acid (PDLLA) was blended with type I collagen to attempt to overcome the instantaneous gelation of electrospun collagen scaffolds in biological environments. Scaffolds based on blends of type I collagen and PDLLA were investigated for material stability in cell culture conditions (37 {\\deg}C; 5% CO2) in which post-electrospinning glutaraldehyde crosslinking was also applied. The resulting wet-stable webs were cultured with bone marrow stromal cells (HBMSC) for five weeks. Scanning electron microscopy (SEM), confocal laser scanning microscopy (CLSM), Fourier transform infra-red spectroscopy (FTIR) and biochemical assays were used to characterise the scaffolds and the consequent cell-scaffold constructs. To investigate any electrospinning-induced denaturation of collagen, identical PDLLA/collagen and PDLLA/gelatine blends were electrospun and their potential to promote osteogenic differentiation investigated. PDLLA/collagen blends with w/w ratios of 40/60, 60/40 and 80/20 resulted in satisfactory...

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

    OpenAIRE

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

    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 fo...

  9. Collagen/chitosan porous bone tissue engineering composite scaffold incorporated with Ginseng compound K.

    Science.gov (United States)

    Muthukumar, Thangavelu; Aravinthan, Adithan; Sharmila, Judith; Kim, Nam Soo; Kim, Jong-Hoon

    2016-11-01

    In this study, suitable scaffold materials for bone tissue engineering were successfully prepared using fish scale collagen, hydroxyapatite, chitosan, and beta-tricalcium phosphate. Porous composite scaffolds were prepared by freeze drying method. The Korean traditional medicinal ginseng compound K, a therapeutic agent for the treatment of osteoporosis that reduces inflammation and enhances production of bone morphogenetic protein-2, was incorporated into the composite scaffold. The scaffold was characterized for pore size, swelling, density, degradation, mineralization, cell viability and attachment, and its morphological features were examined using scanning electron microscopy. This characterization and in vitro analysis showed that the prepared scaffold was biocompatible and supported the growth of MG-63 cells, and therefore has potential as an alternative approach for bone regeneration. PMID:27516305

  10. Fibronectin- and collagen-mimetic ligands regulate bone marrow stromal cell chondrogenesis in three-dimensional hydrogels

    Directory of Open Access Journals (Sweden)

    JT Connelly

    2011-09-01

    Full Text Available Modification of tissue engineering scaffolds with bioactive molecules is a potential strategy for modulating cell behavior and guiding tissue regeneration. While adhesion to RGD peptides has been shown to inhibit in vitro chondrogenesis, the effects of extracellular matrix (ECM-mimetic ligands with complex secondary and tertiary structures are unknown. This study aimed to determine whether collagen- and fibronectin-mimetic ligands would retain biologic functionality in three-dimensional (3D hydrogels, whether different ECM-mimetic ligands differentially influence in vitro chondrogenesis, and if effects of ligands on differentiation depend on soluble biochemical stimuli. A linear RGD peptide, a recombinant fibronectin fragment containing the seven to ten Type III repeats (FnIII7-10 and a triple helical, collagen mimetic peptide with the GFOGER motif were covalently coupled to agarose gels using the sulfo-SANPAH crosslinker, and bone marrow stromal cells (BMSCs were cultured within the 3D hydrogels. The ligands retained biologic functionality within the agarose gels and promoted density-dependent BMSC spreading. Interactions with all adhesive ligands inhibited stimulation by chondrogenic factors of collagen Type II and aggrecan mRNA levels and deposition of sulfated glycosaminoglycans. In medium containing fetal bovine serum, interactions with the GFOGER peptide enhanced mRNA expression of the osteogenic gene osteocalcin whereas FnIII7-10 inhibited osteocalcin expression. In conclusion, modification of agarose hydrogels with ECM-mimetic ligands can influence the differentiation of BMSCs in a manner that depends strongly on the presence and nature of soluble biochemical stimuli.

  11. MT1-MMP and type II collagen specify skeletal stem cells and their bone and cartilage progeny

    DEFF Research Database (Denmark)

    Szabova, Ludmila; Yamada, Susan S; Wimer, Helen;

    2009-01-01

    -expressing cells of the skeleton rescues not only diminished chondrocyte proliferation, but surprisingly, also results in amelioration of the severe skeletal dysplasia associated with MT1-MMP deficiency through enhanced bone formation. Consistent with this increased bone formation, type II collagen was identified...

  12. A mouse 3T6 fibroblast cell culture model for the study of normal and protein-engineered collagen synthesis and deposition into the extracellular matrix.

    Science.gov (United States)

    Lamandé, S R; Bateman, J F

    1993-07-01

    Mouse 3T6 fibroblasts deposited an organized collagenous extracellular matrix during long-term culture in the presence of ascorbic acid. The matrix produced by the cells had a similar distribution of collagen types as the mouse dermal matrix, comprising predominantly type I with smaller amounts of types III and V collagens. By day 8 of culture more than 70% of the collagen in the 3T6 matrix was involved in covalent crosslinkages and required pepsin digestion for extraction. Incorporation of NaB3H4 into reducible crosslinks and aldehydes directly demonstrated the involvement of the alpha 1 (I)CB6 and alpha 2(I)CB3.5 in crosslinks. The pattern of reducible crosslinks in the in vitro 3T6 matrix was similar to that in mouse skin suggesting a comparable fibril organization. Processing of procollagen to collagen occurred efficiently throughout the culture period and the rate of collagen production was unaltered during 15 days of culture, indicating that the development of a collagenous matrix does not directly play a role in procollagen processing or biosynthetic regulation. The existence of a preformed matrix did however, increase the efficiency with which newly synthesised collagen was incorporated into the pericellular matrix. At day 0, when there was no measurable matrix present, 29% of the collagen synthesised was deposited, while by day 15, 88% of the collagen was laid down in the matrix. The development of this 3T6 culture system, where collagen is efficiently incorporated into an organized extracellular matrix, will facilitate detailed studies on matrix organization and regulation and provide a system in which protein-engineered mutant collagens can be expressed to determine their effects on the production of a functional extracellular matrix. PMID:8412990

  13. The effects of glucocorticoid on microarchitecture, collagen, mineral and mechanical properties of sheep femur cortical bone.

    Science.gov (United States)

    Ding, Ming; Danielsen, Carl Christian; Overgaard, Søren

    2012-06-01

    In this study, 18 female skeletally mature sheep were randomly allocated into three groups of six each. Group 1 (glucocorticoid-1) received prednisolone treatment (0.60 mg/kg/day, five times weekly) for 7 months. Group 2 (glucocorticoid-2) received the same treatment regime followed by observation of 3 months without treatment. Group 3 was left untreated and served as controls. All sheep received a restricted diet with low calcium and phosphorus. At sacrifice, cortical bone samples from the femur midshaft of each sheep were harvested, micro-CT scanned and subjected to three-point bending and tensile strength testing. Bone collagen and mineral were determined. Cortical porosity was significantly increased in the glucocorticoid-2 compared with the glucocorticoid-1 and control groups. Apparent density was significantly decreased in the glucocorticoid-2 compared with the glucocorticoid-1 group. Collagen content was significantly increased in the glucocorticoid-2 compared with the glucocorticoid-1 and control groups. Bone mineral content did not differ between the groups. Neither the three-point bending mechanical properties nor the tensile mechanical properties differed significantly between the groups, while there was a trend towards decreasing bending mechanical properties in the glucocorticoid-2 group. In conclusion, 7 months of glucocorticoid treatment with malnutrition had a significant impact on the cortical microarchitecture of the sheep femur midshaft. These observed changes occurred 3 months after glucocorticoid cessation, suggesting a delayed effect of glucocorticoid on cortical bone. Thus, changes in cortical bone beyond cancellous bone might further increase fracture risk in patients treated with glucocorticoids. This model might be used as a glucocorticoid-induced osteoporotic model for orthopaedic biomaterial, joint prosthesis and medical device researches.

  14. Effect of local hemostatics on bone induction in rats: a comparative study of bone wax, fibrin-collagen paste, and bioerodible polyorthoester with and without gentamicin

    DEFF Research Database (Denmark)

    Solheim, E; Pinholt, E M; Bang, G;

    1992-01-01

    evaluated by light microscopy and 85Sr uptake analyses. Non-absorbable bone wax of 88% beeswax and absorbable bovine fibrin-collagen paste both significantly inhibited osteoinduction, whereas a bioerodible polyorthoester drug delivery system with or without 4% gentamicin did not. Bone wax was not absorbed...

  15. Defective collagen crosslinking in bone, but not in ligament or cartilage, in bruck syndrome: Indications for a bone-specific telopeptide lysyl hydroxylase on chromosome 17

    NARCIS (Netherlands)

    Bank, R.A.; Robins, S.P.; Wijmenga, C.; Breslau-Siderius, L.J.; Bardoel, A.F.J.; Sluijs, H.A. van der; Pruijs, H.E.H.; Tekoppele, J.M.

    1999-01-01

    Bruck syndrome is characterized by the presence of osteoporosis, joint contractures, fragile bones, and short stature. We report that lysine residues within the telopeptides of collagen type I in bone are underhydroxylated, leading to aberrant crosslinking, but that the lysine residues in the triple

  16. Enalapril alters the formation of the collagen matrix in spontaneously hypertensive rats

    Directory of Open Access Journals (Sweden)

    Alfredo de Souza Bomfim

    2003-07-01

    Full Text Available OBJECTIVE: To assess the effect of the inhibition of the angiotensin-converting enzyme on the collagen matrix (CM of the heart of newborn spontaneously hypertensive rats (SHR during embryonic development. METHODS: The study comprised the 2 following groups of SHR (n=5 each: treated group - rats conceived from SHR females treated with enalapril maleate (15 mg. kg-1.day-1 during gestation; and nontreated group - offspring of nontreated females. The newborns were euthanized within the first 24 hours after birth and their hearts were removed and processed for histological study. Three fields per animal were considered for computer-assisted digital analysis and determination of the volume densities (Vv of the nuclei and CM. The images were segmented with the aid of Image Pro Plus® 4.5.029 software (Media Cybernetics. RESULTS: No difference was observed between the treated and nontreated groups in regard to body mass, cardiac mass, and the relation between cardiac and body mass. A significant reduction in the Vv[matrix] and a concomitant increase in the Vv[nuclei] were observed in the treated group as compared with those in the nontreated group. CONCLUSION: The treatment with enalapril of hypertensive rats during pregnancy alters the collagen content and structure of the myocardium of newborns.

  17. Endothelial Cell Culture on Fibrillar Collagen: Model to Study Platelet Adhesion and Liposome Targeting to Intercellular Collagen Matrix

    Science.gov (United States)

    Chazov, E. I.; Alexeev, A. V.; Antonov, A. S.; Koteliansky, V. E.; Leytin, V. L.; Lyubimova, E. V.; Repin, V. S.; Sviridov, D. D.; Torchilin, V. P.; Smirnov, V. N.

    1981-09-01

    Human umbilical endothelial cells (ECs) were grown on fibrillar type I collagen in 16.4-mm multiwell tissue culture plates. Human platelets were added to the wells, and platelet adhesion to collagen was examined by scanning electron microscopy and radioisotopic technique in the absence of ECs and in preconfluent and confluent EC cultures. Single adherent platelets of different shapes as well as small aggregates were seen on collagen surface. Human plasma fibronectin added to the system stimulated platelet adhesion and their spreading on collagen. ECs had no effect on the percentage of platelets adherent to collagen-coated gaps in preconfluent culture but decreased the number of spread platelets. It is demonstrated that collagen-coated gaps can bind 14C-labeled liposome-antibody and 14C-labeled liposome-fibronectin conjugates. ECs grown on fibrillar collagen are suggested as useful models for screening of antiplatelet drugs and for the study of drug targeting to the areas of vascular injury for prevention of thrombosis.

  18. A bone-like nano-hydroxyapatite/collagen loaded injectable scaffold

    International Nuclear Information System (INIS)

    From a clinical perspective, the use of injectable scaffolds is very attractive as it minimizes patient discomfort, risk of infection, scar formation and the cost of treatment. Bone refers to a family of materials that are constructed by mineralized collagen fibrils. The main objective of this research was to develop a bone-like nano-hydroxyapatite/collagen (nHAC) loaded chitosan (C)/β-glycerophosphate (GP) injectable scaffold. The feasibility of developing a thermo-sensitive and injectable chitosan solution in the presence of nHAC was demonstrated. Bone-marrow-derived messenchymal stem cells (MSCs) were used to measure the cell proliferation of C/GP/nHAC scaffolds based on the cell count kit-8 (CCK-8) assay. It was found that MSCs proliferated normally with the C/GP/nHAC composite scaffolds. The C/GP/nHAC composite scaffolds developed in this study exhibited good injectability, thermo-irreversible properties and solidified under mild conditions. No more than 0.02 g ml-1 of nHAC filler was required to form a non-decaying hydrogel.

  19. A Novel HA/β-TCP-Collagen Composite Enhanced New Bone Formation for Dental Extraction Socket Preservation in Beagle Dogs

    OpenAIRE

    Ko-Ning Ho; Eisner Salamanca; Kuo-Chi Chang; Tsai-Chin Shih; Yu-Chi Chang; Haw-Ming Huang; Nai-Chia Teng; Che-Tong Lin; Sheng-Wei Feng; Wei-Jen Chang

    2016-01-01

    Past studies in humans have demonstrated horizontal and vertical bone loss after six months following tooth extraction. Many biomaterials have been developed to preserve bone volume after tooth extraction. Type I collagen serves as an excellent delivery system for growth factors and promotes angiogenesis. Calcium phosphate ceramics have also been investigated because their mineral chemistry resembles human bone. The aim of this study was to compare the performance of a novel bioresorbable pur...

  20. Poly (lactide-co-glycolide nanofibers coated with collagen and nano-hydroxyapatite for bone tissue engineering

    Directory of Open Access Journals (Sweden)

    Reza Tavakoli-Darestani

    2013-05-01

    Full Text Available Please cite this article as: Tavakoli-Darestani R, Kazemian GH, Emami M, Kamrani-Rad A. Poly (lactide-co-glycolide nanofibers coated with collagen and nano-hydroxyapatite for bone tissue engineering. Novel Biomed 2013;1:8-15.Background: A combination of polymeric nanofibrous scaffold and bioactive materials is potentially useful in bone regeneration applications.Materials and Methods: In the present study, Poly (lactide-co-glycolide (PLGA nanofibrous scaffolds, fabricated via electrospinning, were initially coated with Type I collagen and then with nano-hydroxyapatite. The prepared scaffolds were then characterized using SEM and their ability for bone regeneration was investigated in a rat critical size bone defect using digital mammography, multislice spiral-computed tomography (MSCT imaging, and histological analysis.Results: Electrospun scaffolds had nanofibrous structure with homogenous distribution of n-HA on collagen-grafted PLGA. After 8 weeks of implantation, no sign of inflammation or complication was observed at the site of surgery. According to digital mammography and MSCT, PLGA nanofibers coated simultaneously with collagen and HA showed the highest regeneration in rat calvarium. In addition, no significant difference was observed in bone repair in the group which received PLGA and the untreated control. This amount was lower than that observed in the group implanted with collagen-coated PLGA. Histological studies confirmed these data and showed osteointegration to the surrounding tissue.Conclusion: Taking all together, it was demonstrated that nanofibrous structures can be used as appropriate support for tissue-engineered scaffolds, and coating them with bioactive materials will provide ideal synthetic grafts. Fabricated PLGA coated with Type I collagen and HA can be used as new bone graft substitutes in orthopaedic surgery and is capable of enhancing bone regeneration via characteristics such as osteoconductivity and

  1. Analysis of forward and backward Second Harmonic Generation images to probe the nanoscale structure of collagen within bone and cartilage.

    Science.gov (United States)

    Houle, Marie-Andrée; Couture, Charles-André; Bancelin, Stéphane; Van der Kolk, Jarno; Auger, Etienne; Brown, Cameron; Popov, Konstantin; Ramunno, Lora; Légaré, François

    2015-11-01

    Collagen ultrastructure plays a central role in the function of a wide range of connective tissues. Studying collagen structure at the microscopic scale is therefore of considerable interest to understand the mechanisms of tissue pathologies. Here, we use second harmonic generation microscopy to characterize collagen structure within bone and articular cartilage in human knees. We analyze the intensity dependence on polarization and discuss the differences between Forward and Backward images in both tissues. Focusing on articular cartilage, we observe an increase in Forward/Backward ratio from the cartilage surface to the bone. Coupling these results to numerical simulations reveals the evolution of collagen fibril diameter and spatial organization as a function of depth within cartilage. PMID:26349534

  2. Compositional and in Vitro Evaluation of Nonwoven Type I Collagen/Poly-dl-lactic Acid Scaffolds for Bone Regeneration

    Directory of Open Access Journals (Sweden)

    Xiangchen Qiao

    2015-08-01

    Full Text Available Poly-dl-lactic acid (PDLLA was blended with type I collagen to attempt to overcome the instantaneous gelation of electrospun collagen scaffolds in biological environments. Scaffolds based on blends of type I collagen and PDLLA were investigated for material stability in cell culture conditions (37 °C; 5% CO2 in which post-electrospinning glutaraldehyde crosslinking was also applied. The resulting wet-stable webs were cultured with bone marrow stromal cells (HBMSC for five weeks. Scanning electron microscopy (SEM, confocal laser scanning microscopy (CLSM, Fourier transform infra-red spectroscopy (FTIR and biochemical assays were used to characterise the scaffolds and the consequent cell-scaffold constructs. To investigate any electrospinning-induced denaturation of collagen, identical PDLLA/collagen and PDLLA/gelatine blends were electrospun and their potential to promote osteogenic differentiation investigated. PDLLA/collagen blends with w/w ratios of 40/60, 60/40 and 80/20 resulted in satisfactory wet stabilities in a humid environment, although chemical crosslinking was essential to ensure long term material cell culture. Scaffolds of PDLLA/collagen at a 60:40 weight ratio provided the greatest stability over a five-week culture period. The PDLLA/collagen scaffolds promoted greater cell proliferation and osteogenic differentiation compared to HMBSCs seeded on the corresponding PDLLA/gelatine scaffolds, suggesting that any electrospinning-induced collagen denaturation did not affect material biofunctionality within 5 weeks in vitro.

  3. REGENERATION OF ARTICULAR CARTILAGE UNDER THE IMPLANTATION OF BONE MATRIX

    Directory of Open Access Journals (Sweden)

    Yuri M. Iryanov, Nikolay A. Kiryanov, Olga V. Dyuriagina , Tatiana Yu. Karaseva, Evgenii A. Karasev

    2015-07-01

    Full Text Available Background: The damage or loss of articular cartilage is costly medical problem. The purpose of this work – morphological analysis of reparative chondrogenesis when implanted in the area of the knee joint cartilage of granulated mineralized bone matrix. Material and Methods: The characteristic features of the knee cartilage regeneration studied experimentally in pubertal Wistar rats after modeling a marginal perforated defect and implantation of granulated mineralized bone matrix obtained according to original technology without heat and demineralizing processing into the injury zone. Results: This biomaterial established to have pronounced chondro- and osteoinductive properties, and to provide prolonged activation of reparative process, accelerated organotypical remodeling and restoration of the articular cartilage injured. Conclusion: The data obtained demonstrate the efficacy of МВМ in clinical practice for the treatment of diseases and injuries of the articular cartilage.

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

    International Nuclear Information System (INIS)

    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 - Highlights: • Demineralized bone matrix (DBM) was gamma-irradiated for sterilization. • Irradiated DBM had higher alkaline phosphatase and osteocalcin production. • It was reasoned the more released bone morphogenetic proteins by irradiation. • This result supports the application of radiation sterilization for bone implants

  5. 3D collagen type I matrix inhibits the antimigratory effect of doxorubicin

    Directory of Open Access Journals (Sweden)

    Millerot-Serrurot Emilie

    2010-08-01

    Full Text Available Abstract Background The cell microenvironment, especially extracellular matrix proteins, plays an important role in tumor cell response to chemotherapeutic drugs. The present study was designed to investigate whether this microenvironment can influence the antimigratory effect of an anthracycline drug, doxorubicin, when tumor cells are grown in a matrix of type I collagen, a three-dimensional (3D context which simulates a natural microenvironment. Methods To this purpose, we studied the migratory parameters, the integrin expression, and the activation state of focal adhesion kinase (FAK and GTPase RhoA involved in the formation of focal adhesions and cell movement. These parameters were evaluated at non toxic concentrations which did not affect HT1080 cell proliferation. Results We show that while doxorubicin decreased cell migration properties by 70% in conventional two-dimensional (2D culture, this effect was completely abolished in a 3D one. Regarding the impact of doxorubicin on the focal adhesion complexes, unlike in 2D systems, the data indicated that the drug neither affected β1 integrin expression nor the state of phosphorylation of FAK and RhoA. Conclusion This study suggests the lack of antiinvasive effect of doxorubicin in a 3D environment which is generally considered to better mimic the phenotypic behaviour of cells in vivo. Consistent with the previously shown resistance to the cytotoxic effect in a 3D context, our results highlight the importance of the matrix configuration on the tumor cell response to antiinvasive drugs.

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

    Science.gov (United States)

    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.

  7. Biodegradation, biocompatibility, and osteoconduction evaluation of collagen-nanohydroxyapatite cryogels for bone tissue regeneration.

    Science.gov (United States)

    Salgado, Christiane Laranjo; Grenho, Liliana; Fernandes, Maria Helena; Colaço, Bruno Jorge; Monteiro, Fernando Jorge

    2016-01-01

    Designing biomimetic biomaterials inspired by the natural complex structure of bone and other hard tissues is still a challenge nowadays. The control of the biomineralization process onto biomaterials should be evaluated before clinical application. Aiming at bone regeneration applications, this work evaluated the in vitro biodegradation and interaction between human bone marrow stromal cells (HBMSC) cultured on different collagen/nanohydroxyapatite cryogels. Cell proliferation, differentiation, morphology, and metabolic activity were assessed through different protocols. All the biocomposite materials allowed physiologic apatite deposition after incubation in simulated body fluid and the cryogel with the highest nanoHA content showed to have the highest mechanical strength (DMA). The study clearly showed that the highest concentration of nanoHA granules on the cryogels were able to support cell type's survival, proliferation, and individual functionality in a monoculture system, for 21 days. In fact, the biocomposites were also able to differentiate HBMSCs into osteoblastic phenotype. The composites behavior was also assessed in vivo through subcutaneous and bone implantation in rats to evaluate its tissue-forming ability and degradation rate. The cryogels Coll/nanoHA (30 : 70) promoted tissue regeneration and adverse reactions were not observed on subcutaneous and bone implants. The results achieved suggest that scaffolds of Coll/nanoHA (30 : 70) should be considered promising implants for bone defects that present a grotto like appearance with a relatively small access but a wider hollow inside. This material could adjust to small dimensions and when entering into the defect, it could expand inside and remain in close contact with the defect walls, thus ensuring adequate osteoconductivity.

  8. Bone collagen stable carbon and nitrogen isotope variability in modern South Australian mammals: A baseline for palaeoecological inferences

    International Nuclear Information System (INIS)

    Cortical bone samples were collected from a range of modern mammals at four field sites along a 1225 km north-south transect from temperate coastal to arid interior South Australia in order to address variability in stable carbon and nitrogen isotope composition. Collection sites were located along the eastern border of the state and included Mount Gambier, Karte, Plumbago and Innamincka. Mean annual rainfall along the transect ranges from 700-800 mm at Mount Gambier to 150-200 mm at Innamincka. Bone collagen carbon and nitrogen isotope values become more positive toward the arid north in relation to increasing quantities of C-4 plants and decreasing amounts of rainfall. respectively. In addition, carnivores and herbivores can be differentiated by stable nitrogen isotope values. On average, carnivore bone collagen is approximately 6 per mil more positive than that of rabbits at Mount Gambier but only 2.6 - 3.4 per mil more positive at the three arid collection sites. In general, the large eutherian herbivores have mean bone collagen δ15N values that are 1.4 - 2.3 per mil more positive than those of the marsupial herbivores. Eutherian and marsupial bone collagen δ15N differences only disappear at the most arid collection site, Innamincka

  9. Bone collagen stable carbon and nitrogen isotope variability in modern South Australian mammals: A baseline for palaeoecological inferences.

    Energy Technology Data Exchange (ETDEWEB)

    Pate, F.D.; Anson, T.J.; Noble, A.H. [Flinders Univ. of South Australia, Bedford Park, SA (Australia). Department of Archaeology; Schoeninger, M.J. [Wisconsin Univ., Madison, WI (United States). Department of Anthropology

    1997-12-31

    Cortical bone samples were collected from a range of modern mammals at four field sites along a 1225 km north-south transect from temperate coastal to arid interior South Australia in order to address variability in stable carbon and nitrogen isotope composition. Collection sites were located along the eastern border of the state and included Mount Gambier, Karte, Plumbago and Innamincka. Mean annual rainfall along the transect ranges from 700-800 mm at Mount Gambier to 150-200 mm at Innamincka. Bone collagen carbon and nitrogen isotope values become more positive toward the arid north in relation to increasing quantities of C-4 plants and decreasing amounts of rainfall. respectively. In addition, carnivores and herbivores can be differentiated by stable nitrogen isotope values. On average, carnivore bone collagen is approximately 6 per mil more positive than that of rabbits at Mount Gambier but only 2.6 - 3.4 per mil more positive at the three arid collection sites. In general, the large eutherian herbivores have mean bone collagen {delta}15N values that are 1.4 - 2.3 per mil more positive than those of the marsupial herbivores. Eutherian and marsupial bone collagen {delta}15N differences only disappear at the most arid collection site, Innamincka.

  10. Synergistic intrafibrillar/extrafibrillar mineralization of collagen scaffolds based on a biomimetic strategy to promote the regeneration of bone defects

    Directory of Open Access Journals (Sweden)

    Wang Y

    2016-05-01

    Full Text Available Yao Wang,1 Ngo Van Manh,1,2 Haorong Wang,1 Xue Zhong,1 Xu Zhang,1 Changyi Li1 1School of Dentistry, Hospital of Stomatology, Tianjin Medical University, Tianjin, People’s Republic of China; 2Thaibinh University of Medicine and Pharmacy, Thaibinh, Vietnam Abstract: The mineralization of collagen scaffolds can improve their mechanical properties and biocompatibility, thereby providing an appropriate microenvironment for bone regeneration. The primary purpose of the present study is to fabricate a synergistically intra- and extrafibrillar mineralized collagen scaffold, which has many advantages in terms of biocompatibility, biomechanical properties, and further osteogenic potential. In this study, mineralized collagen scaffolds were fabricated using a traditional mineralization method (ie, immersed in simulated body fluid as a control group and using a biomimetic method based on the polymer-induced liquid precursor process as an experimental group. In the polymer-induced liquid precursor process, a negatively charged polymer, carboxymethyl chitosan (CMC, was used to stabilize amorphous calcium phosphate (ACP to form nanocomplexes of CMC/ACP. Collagen scaffolds mineralized based on the polymer-induced liquid precursor process were in gel form such that nanocomplexes of CMC/ACP can easily be drawn into the interstices of the collagen fibrils. Scanning electron microscopy and transmission electron microscopy were used to examine the porous micromorphology and synergistic mineralization pattern of the collagen scaffolds. Compared with simulated body fluid, nanocomplexes of CMC/ACP significantly increased the modulus of the collagen scaffolds. The results of in vitro experiments showed that the cell count and differentiated degrees in the experimental group were higher than those in the control group. Histological staining and micro-computed tomography showed that the amount of new bone regenerated in the experimental group was larger than that in the

  11. Radiation-induced myosin IIA expression stimulates collagen type I matrix reorganization

    International Nuclear Information System (INIS)

    Background and purpose: Extracellular matrix (ECM) reorganization critically contributes to breast cancer (BC) progression and radiotherapy response. We investigated the molecular background and functional consequences of collagen type I (col-I) reorganization by irradiated breast cancer cells (BCC). Materials and methods: Radiation-induced (RI) col-I reorganization was evaluated for MCF-7/6, MCF-7/AZ, T47D and SK-BR-3 BCC. Phase-contrast microscopy and a stressed matrix contraction assay were used for visualization and quantification of col-I reorganization. Cell–matrix interactions were assessed by the inhibition of β1 integrin (neutralizing antibody ‘P5D2’) or focal adhesion kinase (FAK; GSK22560098 small molecule kinase inhibitor). The role of the actomyosin cytoskeleton was explored by western blotting analysis of myosin II expression and activity; and by gene silencing of myosin IIA and pharmacological inhibition of the actomyosin system (blebbistatin, cytochalasin D). BCC death was evaluated by propidium iodide staining. Results: We observed a radiation dose-dependent increase of col-I reorganization by BCC. β1 Integrin/FAK-mediated cell–matrix interactions are essential for RI col-I reorganization. Irradiated BCC are characterized by increased myosin IIA expression and myosin IIA-dependent col-I reorganization. Moreover, RI col-I reorganization by BCC is associated with decreased BCC death, as suggested by pharmacological targeting of the β1 integrin/FAK/myosin IIA pathway. Conclusions: Our data indicate the role of myosin IIA in col-I reorganization by irradiated BCC and reciprocal BCC death

  12. Identification of a new hominin bone from Denisova Cave, Siberia using collagen fingerprinting and mitochondrial DNA analysis

    Science.gov (United States)

    Brown, Samantha; Higham, Thomas; Slon, Viviane; Pääbo, Svante; Meyer, Matthias; Douka, Katerina; Brock, Fiona; Comeskey, Daniel; Procopio, Noemi; Shunkov, Michael; Derevianko, Anatoly; Buckley, Michael

    2016-03-01

    DNA sequencing has revolutionised our understanding of archaic humans during the Middle and Upper Palaeolithic. Unfortunately, while many Palaeolithic sites contain large numbers of bones, the majority of these lack the diagnostic features necessary for traditional morphological identification. As a result the recovery of Pleistocene-age human remains is extremely rare. To circumvent this problem we have applied a method of collagen fingerprinting to more than 2000 fragmented bones from the site of Denisova Cave, Russia, in order to facilitate the discovery of human remains. As a result of our analysis a single hominin bone (Denisova 11) was identified, supported through in-depth peptide sequencing analysis, and found to carry mitochondrial DNA of the Neandertal type. Subsequent radiocarbon dating revealed the bone to be >50,000 years old. Here we demonstrate the huge potential collagen fingerprinting has for identifying hominin remains in highly fragmentary archaeological assemblages, improving the resources available for wider studies into human evolution.

  13. The Study of Barrier Function of Collagen Membrane “Osteoplast” in Healing Bone Defects in an Experiment

    Directory of Open Access Journals (Sweden)

    Ivanov S.Y.

    2011-09-01

    Full Text Available The aim of the work is to study barrier properties of collagen membrane “Osteoplast” (“Vitaform”, Russia in closing critical bone defect in an experiment. Materials and Methods. The experiments have been carried out on 20 rabbits of “chinchilla” breed. Results. “Osteoplast”, a membrane made on the basis of bone collagen, is reabsorbed and serves as a safe barrier for fibroblasts migration into bone defect area. Its application enables to protect the defect area from fibrous tissue penetrating and initiate bone regeneration. Osseous tissue beneath a membrane goes few differentiation stages, has classical structure including all structural elements (osteons, lacunes, blood vessels that provides its perfect strength characteristics.

  14. Self-assembled composite matrix in a hierarchical 3-D scaffold for bone tissue engineering

    DEFF Research Database (Denmark)

    Chen, Muwan; Le, Dang Quang Svend; Baatrup, Anette;

    2011-01-01

    MSC seeding efficiency, proliferation, distribution and differentiation. Porous PCL meshes prepared by fused deposition modeling (FDM) were embedded in matrix of hyaluronic acid, methylated collagen and terpolymer via polyelectrolyte complex coacervation. Scaffolds were cultured statically and dynamically...

  15. Efficacy of guided bone regeneration using composite bone graft and resorbable collagen membrane in Seibert's Class I ridge defects: radiological evaluation.

    Science.gov (United States)

    Saravanan, Pushparajan; Ramakrishnan, T; Ambalavanan, N; Emmadi, Pamela; John, Thomas Libby

    2013-08-01

    The purpose of the study was to evaluate radiologically the efficacy of guided bone regeneration using composite bone graft (autogenous bone graft and anorganic bovine bone graft [Bio-Oss]) along with resorbable collagen membrane (BioMend Extend) in the augmentation of Seibert's class I ridge defects in maxilla. Bone width was evaluated using computerized tomography at day 0 and at day 180 at 2 mm, 4 mm, and 6 mm from the crest. There was a statistically significant increase in bone width between day 0 and day 180 at 2 mm, 4 mm, and 6 mm from the crest. The results of the study demonstrated an increase in bone width of Seibert's class I ridge defects in the maxilla of the study patients. PMID:23964779

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

    Directory of Open Access Journals (Sweden)

    Jung-Bo Huh

    2015-07-01

    Full Text Available 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.

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

    Science.gov (United States)

    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

  18. Calcium phosphate fibers coated with collagen: In vivo evaluation of the effects on bone repair.

    Science.gov (United States)

    Ueno, Fabio Roberto; Kido, Hueliton Wilian; Granito, Renata Neves; Gabbai-Armelin, Paulo Roberto; Magri, Angela Maria Paiva; Fernandes, Kelly Rosseti; da Silva, Antonio Carlos; Braga, Francisco José Correa; Renno, Ana Claudia Muniz

    2016-08-12

    The aim of this study was to assess the characteristics of the CaP/Col composites, in powder and fiber form, via scanning electron microscopy (SEM), pH and calcium release evaluation after immersion in SBF and to evaluate the performance of these materials on the bone repair process in a tibial bone defect model. For this, four different formulations (CaP powder - CaPp, CaP powder with collagen - CaPp/Col, CaP fibers - CaPf and CaP fibers with collagen - CaPf/Col) were developed. SEM images indicated that both material forms were successfully coated with collagen and that CaPp and CaPf presented HCA precursor crystals on their surface. Although presenting different forms, FTIR analysis indicated that CaPp and CaPf maintained the characteristic peaks for this class of material. Additionally, the calcium assay study demonstrated a higher Ca uptake for CaPp compared to CaPf for up to 5 days. Furthermore, pH measurements revealed that the collagen coating prevented the acidification of the medium, leading to higher pH values for CaPp/Col and CaPf/Col. The histological analysis showed that CaPf/Col demonstrated a higher amount of newly formed bone in the region of the defect and a reduced presence of material. In summary, the results indicated that the fibrous CaP enriched with the organic part (collagen) glassy scaffold presented good degradability and bone-forming properties and also supported Runx2 and RANKL expression. These results show that the present CaP/Col fibrous composite may be used as a bone graft for inducing bone repair. PMID:27567780

  19. Treatment of life-threatening wounds with a combination of allogenic platelet-rich plasma, fibrin glue and collagen matrix, and a literature review.

    Science.gov (United States)

    Asadi, Mehdi; Alamdari, Daryoush Hamidi; Rahimi, Hamid Reza; Aliakbarian, Mohsen; Jangjoo, Ali; Abdollahi, Abbas; Bahar, Mostafa Mehrabi; Azadmand, Ali; Forghani, Naser; Sadegh, Mohammad Nori; Khayamy, Mohammad Esmail; Seifalian, Alexander

    2014-08-01

    Currently there is no ideal procedure for the treatment of recalcitrant ulcers that are unresponsive to the majority of common treatments. However, several novel approaches have been proposed, including bone marrow stem cells, platelets, fibrin glue and collagen matrix. For the first approach treatment of a chronic wound, a non-invasive method is highly desirable. The present study was undertaken with the aim of evaluating the effect of a combination of platelets, fibrin glue and collagen matrix (PFC) in one treatment. A total of ten patients with aggressive, refractory, life-threatening wounds were recruited for the study and their treatment effects were evaluated. Initially, the ulcers were extensively debrided, measured and photographed at weekly intervals. The PFC combination was applied topically to the wound every two days. Following treatment, the wound was completely closed in nine patients and was markedly reduced in the other patient. The mean 100% healing time for the nine patients was 11.3±5.22 weeks. There was no evidence of local or systemic complications or any abnormal tissue formation, keloid or hypertrophic scarring. Therefore, the results of the present study indicate that in the first approach, the combination of PFC components may be used safely in order to synergize the effect of chronic wound healing.

  20. Checking collagen preservation in archaeological bone by non-destructive studies (Micro-CT and IBA)

    Energy Technology Data Exchange (ETDEWEB)

    Beck, L., E-mail: lucile.beck@cea.fr [C2RMF - UMR171 CNRS, Centre de Recherche et de Restauration des Musees de France, Palais du Louvre, Porte des Lions, 14 quai Francois Mitterrand, 75001 Paris (France); CEA, DEN, Service de Recherches de Metallurgie Physique, Laboratoire JANNUS, 91191 Gif-sur-Yvette (France); Cuif, J.-P. [UMR IDES 8148, Universite Paris XI-Orsay, 91405 Orsay cedex (France); Pichon, L. [C2RMF - UMR171 CNRS, Centre de Recherche et de Restauration des Musees de France, Palais du Louvre, Porte des Lions, 14 quai Francois Mitterrand, 75001 Paris (France); Vaubaillon, S. [CEA, INSTN, Laboratoire JANNUS, 91191 Gif-sur-Yvette (France); Dambricourt Malasse, A. [Departement de Prehistoire, Museum national d' Histoire naturelle, UMR 7194 - CNRS, Institut de Paleontologie Humaine, 1, rue Rene Panhard, 75013 Paris (France); Abel, R.L. [The Natural History Museum, London (United Kingdom)

    2012-02-15

    The material to be studied is a piece of human skull discovered (1999) in Pleistocene sediments from the Orsang river (Gujarat state, India). From anatomical view point, this skull is highly composite: modern Homo sapiens characters are associated to undoubtedly more ancient features. Absolute dating by {sup 14}C is critical to understand this discovery. Prior to dating measurements, non-destructive studies have been carried out. Micro-CT reconstruction (X-ray microtomography) and Ion Beam Analysis (IBA) have been undertaken to check the structural preservation of the fossil and the collagen preservation. PIXE elemental map was used to select well-preserved bone area. RBS/EBS and NRA were used for light element quantification, in particular C, N and O contents. We also demonstrate that the PIXE-RBS/EBS combination is a effective tool for the whole characterization of archaeological and recent bones by analysing in one experiment both mineral and organic fractions. We have shown that the archaeological bone, a fragment of the potentially oldest modern Indian, is enough preserved for radiocarbon dating. We propose that Elastic Backscattering Spectrometry (EBS) using 3 MeV protons could be a good non destructive alternative to conventional CHN method using Carbon-Hydrogen-Nitrogen analyzer for measuring C and N before {sup 14}C dating.

  1. Checking collagen preservation in archaeological bone by non-destructive studies (Micro-CT and IBA)

    International Nuclear Information System (INIS)

    The material to be studied is a piece of human skull discovered (1999) in Pleistocene sediments from the Orsang river (Gujarat state, India). From anatomical view point, this skull is highly composite: modern Homo sapiens characters are associated to undoubtedly more ancient features. Absolute dating by 14C is critical to understand this discovery. Prior to dating measurements, non-destructive studies have been carried out. Micro-CT reconstruction (X-ray microtomography) and Ion Beam Analysis (IBA) have been undertaken to check the structural preservation of the fossil and the collagen preservation. PIXE elemental map was used to select well-preserved bone area. RBS/EBS and NRA were used for light element quantification, in particular C, N and O contents. We also demonstrate that the PIXE-RBS/EBS combination is a effective tool for the whole characterization of archaeological and recent bones by analysing in one experiment both mineral and organic fractions. We have shown that the archaeological bone, a fragment of the potentially oldest modern Indian, is enough preserved for radiocarbon dating. We propose that Elastic Backscattering Spectrometry (EBS) using 3 MeV protons could be a good non destructive alternative to conventional CHN method using Carbon–Hydrogen–Nitrogen analyzer for measuring C and N before 14C dating.

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

    Science.gov (United States)

    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

  3. Efficacy of Mucograft vs Conventional Resorbable Collagen Membranes in Guided Bone Regeneration Around Standardized Calvarial Defects in Rats: A Histologic and Biomechanical Assessment.

    Science.gov (United States)

    Ramalingam, Sundar; Basudan, Amani; Babay, Nadir; Al-Rasheed, Abdulaziz; Nooh, Nasser; Nagshbandi, Jafar; Aldahmash, Abdullah; Atteya, Muhammad; Al-Hezaimi, Khalid

    2016-01-01

    Guided bone regeneration (GBR) using a porcine-derived collagen matrix (Mucograft [MG], Geistlich) has not yet been reported. The aim of this histologic and biomechanical study was to compare the efficacy of MG versus resorbable collagen membranes (RCMs) in facilitating GBR around standardized rat calvarial defects. Forty female Wistar albino rats with a mean age and weight of 6 to 9 weeks and 250 to 300 g, respectively, were used. With the rats under general anesthesia, the skin over the calvaria was exposed using a full-thickness flap. A 4.6-mm-diameter standardized calvarial defect was created in the left parietal bone. For treatment, the rats were randomly divided into four groups (n = 10 per group): (1) MG group: the defect was covered with MG; (2) RCM group: the defect was covered with an RCM; (3) MG + bone group: the defect was filled with bone graft particles and covered by MG; and (4) RCM + bone group: the defect was filled with bone graft particles and covered by an RCM. Primary closure was achieved using interrupted resorbable sutures. The animals were sacrificed at 8 weeks after the surgical procedures. Qualitative histologic analysis and biomechanical assessment to identify hardness and elastic modulus of newly formed bone (NFB) were performed. Collected data were statistically analyzed using one-way analysis of variance. Histologic findings revealed NFB with fibrous connective tissue in all groups. The quantity of NFB was highest in the RCM + bone group. Statistically significant differences in the hardness (F = 567.69, dfN = 3, dfD = 36, P RCM + bone group had the highest mean ± standard deviation (SD) hardness of NFB (531.4 ± 24.9 MPa), the RCM group had the highest mean ± SD elastic modulus of NFB (18.63 ± 1.89 GPa). The present study demonstrated that RCMs are better than MG at enhancing new bone formation in standardized rat calvarial defects when used along with mineralized particulate graft material. PMID:27031638

  4. Adhesive properties of Clostridium perfringens to extracellular matrix proteins collagens and fibronectin.

    Science.gov (United States)

    Hitsumoto, Yasuo; Morita, Naomi; Yamazoe, Ryosuke; Tagomori, Mika; Yamasaki, Tsutomu; Katayama, Seiichi

    2014-02-01

    The adhesive properties of Clostridium perfringens to collagens, gelatin, fibronectin (Fn), Fn-prebound collagens, and Fn-prebound gelatin were investigated. C. perfringens could bind to Fn-prebound collagen type II, type III, and gelatin, but not to gelatin or collagens except for collagen type I directly. Recombinant Fn-binding proteins of C. perfringens, rFbpA and rFbpB, were used to examine Fn-mediated bacterial adherence to collagen type I. In the presence of rFbps, C. perfringens adherence to Fn-prebound collagen type I was inhibited in a dose-dependent manner. Fn was not released from the coated collagen type I by the presence of rFbps, and rFbps did not bind to collagen type I. Thus, the inhibition of C. perfringens binding to Fn-prebound collagen type I by rFbps could not be explained by the removal of Fn from collagen or by the competitive binding of rFbps to collagen. Instead, both rFbps were found to bind to C. perfringens. These results suggest the possibility that rFbps may bind to the putative Fn receptor expressed on C. perfringens and competitively inhibit Fn binding to C. perfringens.

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

    Science.gov (United States)

    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

  6. Synergistic intrafibrillar/extrafibrillar mineralization of collagen scaffolds based on a biomimetic strategy to promote the regeneration of bone defects.

    Science.gov (United States)

    Wang, Yao; Van Manh, Ngo; Wang, Haorong; Zhong, Xue; Zhang, Xu; Li, Changyi

    2016-01-01

    The mineralization of collagen scaffolds can improve their mechanical properties and biocompatibility, thereby providing an appropriate microenvironment for bone regeneration. The primary purpose of the present study is to fabricate a synergistically intra- and extrafibrillar mineralized collagen scaffold, which has many advantages in terms of biocompatibility, biomechanical properties, and further osteogenic potential. In this study, mineralized collagen scaffolds were fabricated using a traditional mineralization method (ie, immersed in simulated body fluid) as a control group and using a biomimetic method based on the polymer-induced liquid precursor process as an experimental group. In the polymer-induced liquid precursor process, a negatively charged polymer, carboxymethyl chitosan (CMC), was used to stabilize amorphous calcium phosphate (ACP) to form nanocomplexes of CMC/ACP. Collagen scaffolds mineralized based on the polymer-induced liquid precursor process were in gel form such that nanocomplexes of CMC/ACP can easily be drawn into the interstices of the collagen fibrils. Scanning electron microscopy and transmission electron microscopy were used to examine the porous micromorphology and synergistic mineralization pattern of the collagen scaffolds. Compared with simulated body fluid, nanocomplexes of CMC/ACP significantly increased the modulus of the collagen scaffolds. The results of in vitro experiments showed that the cell count and differentiated degrees in the experimental group were higher than those in the control group. Histological staining and micro-computed tomography showed that the amount of new bone regenerated in the experimental group was larger than that in the control group. The biomimetic mineralization will assist us in fabricating a novel collagen scaffold for clinical applications. PMID:27274235

  7. Collagen type V enhances matrix contraction by human periodontal ligament fibroblasts seeded in three-dimensional collagen gels.

    NARCIS (Netherlands)

    Berendsen, A.D.; Bronckers, A.L.; Smit, T.H.; Walboomers, X.F.; Everts, V.

    2006-01-01

    Extracellular matrix components play an important role in modulating cellular activity. To study such capacities of the matrix, fibroblasts are frequently cultured in a three-dimensional gel and contraction is assessed as a measure of cellular activity. Since a connective tissue contains several typ

  8. Effect of cefazolin loaded bone matrix gelatin on repairing large segmental bone defects and preventing infection

    Institute of Scientific and Technical Information of China (English)

    游洪波; 陈安民

    2004-01-01

    Objective: To explore the possibility of repairing long segmental bone defects and preventing infection with cefazolin loaded bone matrix gelatin (C-BMG). Methods: C-BMG was made from putting cefazolin into BMG by vacuum absorption and lyophilization techniques. The sustaining period of effective drug concentration in vitro and in vivo was detected. The time of inhibiting bacteria, and the drug concentration in local tissues ( bone and muscle) and plasma after implantation of C-BMG were examined by high performance liquid chromatography.Results: The effective inhibition time to staphylococcus aureus of C-BMG was 22 days in vitro; while 14 days in vivo. The cefazolin concentration in local tissues was higher in early stage, and later it kept a stable and low drug release. C-BMG showed an excellent ability to repair segmental long bone defects.Conclusions: C-BMG can gradually release cefazolin with effective drug concentration and has excellent ability to repair segmental bone defects. It can be used to repair segmental long bone defects and prevent infection after operation.

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

    Science.gov (United States)

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

    2013-12-01

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

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

    Science.gov (United States)

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

    2016-10-01

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

  11. Minimal invasive surgery for unicameral bone cyst using demineralized bone matrix: a case series

    Directory of Open Access Journals (Sweden)

    Cho Hwan

    2012-07-01

    Full Text Available Abstract Background Various treatments for unicameral bone cyst have been proposed. Recent concern focuses on the effectiveness of closed methods. This study evaluated the effectiveness of demineralized bone matrix as a graft material after intramedullary decompression for the treatment of unicameral bone cysts. Methods Between October 2008 and June 2010, twenty-five patients with a unicameral bone cyst were treated with intramedullary decompression followed by grafting of demineralized bone matrix. There were 21 males and 4 female patients with mean age of 11.1 years (range, 3–19 years. The proximal metaphysis of the humerus was affected in 12 patients, the proximal femur in five, the calcaneum in three, the distal femur in two, the tibia in two, and the radius in one. There were 17 active cysts and 8 latent cysts. Radiologic change was evaluated according to a modified Neer classification. Time to healing was defined as the period required achieving cortical thickening on the anteroposterior and lateral plain radiographs, as well as consolidation of the cyst. The patients were followed up for mean period of 23.9 months (range, 15–36 months. Results Nineteen of 25 cysts had completely consolidated after a single procedure. The mean time to healing was 6.6 months (range, 3–12 months. Four had incomplete healing radiographically but had no clinical symptom with enough cortical thickness to prevent fracture. None of these four cysts needed a second intervention until the last follow-up. Two of 25 patients required a second intervention because of cyst recurrence. All of the two had a radiographical healing of cyst after mean of 10 additional months of follow-up. Conclusions A minimal invasive technique including the injection of DBM could serve as an excellent treatment method for unicameral bone cysts.

  12. A Comparative Study of Collagen Matrix Density Effect on Endothelial Sprout Formation Using Experimental and Computational Approaches.

    Science.gov (United States)

    Shamloo, Amir; Mohammadaliha, Negar; Heilshorn, Sarah C; Bauer, Amy L

    2016-04-01

    A thorough understanding of determining factors in angiogenesis is a necessary step to control the development of new blood vessels. Extracellular matrix density is known to have a significant influence on cellular behaviors and consequently can regulate vessel formation. The utilization of experimental platforms in combination with numerical models can be a powerful method to explore the mechanisms of new capillary sprout formation. In this study, using an integrative method, the interplay between the matrix density and angiogenesis was investigated. Owing the fact that the extracellular matrix density is a global parameter that can affect other parameters such as pore size, stiffness, cell-matrix adhesion and cross-linking, deeper understanding of the most important biomechanical or biochemical properties of the ECM causing changes in sprout morphogenesis is crucial. Here, we implemented both computational and experimental methods to analyze the mechanisms responsible for the influence of ECM density on the sprout formation that is difficult to be investigated comprehensively using each of these single methods. For this purpose, we first utilized an innovative approach to quantify the correspondence of the simulated collagen fibril density to the collagen density in the experimental part. Comparing the results of the experimental study and computational model led to some considerable achievements. First, we verified the results of the computational model using the experimental results. Then, we reported parameters such as the ratio of proliferating cells to migrating cells that was difficult to obtain from experimental study. Finally, this integrative system led to gain an understanding of the possible mechanisms responsible for the effect of ECM density on angiogenesis. The results showed that stable and long sprouts were observed at an intermediate collagen matrix density of 1.2 and 1.9 mg/ml due to a balance between the number of migrating and proliferating

  13. Keratocytes are induced to produce collagen type II: A new strategy for in vivo corneal matrix regeneration.

    Science.gov (United States)

    Greene, Carol Ann; Green, Colin R; Dickinson, Michelle E; Johnson, Virginia; Sherwin, Trevor

    2016-09-10

    The stroma, the middle layer of the cornea, is a connective tissue making up most of the corneal thickness. The stromal extracellular matrix (ECM) consists of highly organised lamellae which are made up of tightly packed fibrils primarily composed of collagens type I and V. This layer is interspersed with keratocytes, mesenchymal cells of neural crest origin. We have previously shown that adult corneal keratocytes exhibit phenotypic plasticity and can be induced into a neuronal phenotype. In the current study we evaluated the potential of keratocytes to produce collagen type II via phenotypic reprogramming with exogenous chondrogenic factors. The cornea presents a challenge to tissue engineers owing to its high level of organisation and the phenotypic instability of keratocytes. Traditional approaches based on a scar model do not support the engineering of functional stromal tissue. Type II collagen is not found in the adult cornea but is reported to be expressed during corneal development, raising the possibility of using such an approach to regenerate the corneal ECM. Keratocytes in culture and within intact normal and diseased tissue were induced to produce collagen type II upon treatment with transforming growth factor Beta3 (TGFβ3) and dexamethasone. In vivo treatment of rat corneas also resulted in collagen type II deposition and a threefold increase in corneal hardness and elasticity. Furthermore, the treatment of corneas and subsequent deposition of collagen type II did not cause opacity, fibrosis or scarring. The induction of keratocytes with specific exogenous factors and resulting deposition of type II collagen in the stroma can potentially be controlled by withdrawal of the factors. This might be a promising new approach for in vivo corneal regeneration strategies aimed at increasing corneal integrity in diseases associated with weakened ectatic corneal tissue such as keratoconus. PMID:27539660

  14. Thrombospondin-1 regulates bone homeostasis through effects on bone matrix integrity and nitric oxide signaling in osteoclasts

    OpenAIRE

    Sarah R Amend; Uluckan, Ozge; Hurchla, Michelle; Leib, Daniel; Novack, Deborah Veis; Silva, Matthew; Frazier, William; Weilbaecher, Katherine N.

    2015-01-01

    Thrombospondin-1 (TSP1), an endogenous antiangiogenic, is a widely expressed secreted ligand with roles in migration, adhesion and proliferation and is a target for new therapeutics. While TSP1 is present in the bone matrix and several TSP1 receptors play roles in bone biology, the role of TSP1 in bone remodeling has not been fully elucidated. Bone turnover is characterized by coordinated activity of bone-forming osteoblasts (OB) and bone-resorbing osteoclasts (OC). TSP1−/− mice had increased...

  15. Design and characterization of microcapsules-integrated collagen matrixes as multifunctional three-dimensional scaffolds for soft tissue engineering.

    Science.gov (United States)

    Del Mercato, Loretta L; Passione, Laura Gioia; Izzo, Daniela; Rinaldi, Rosaria; Sannino, Alessandro; Gervaso, Francesca

    2016-09-01

    Three-dimensional (3D) porous scaffolds based on collagen are promising candidates for soft tissue engineering applications. The addition of stimuli-responsive carriers (nano- and microparticles) in the current approaches to tissue reconstruction and repair brings about novel challenges in the design and conception of carrier-integrated polymer scaffolds. In this study, a facile method was developed to functionalize 3D collagen porous scaffolds with biodegradable multilayer microcapsules. The effects of the capsule charge as well as the influence of the functionalization methods on the binding efficiency to the scaffolds were studied. It was found that the binding of cationic microcapsules was higher than that of anionic ones, and application of vacuum during scaffolds functionalization significantly hindered the attachment of the microcapsules to the collagen matrix. The physical properties of microcapsules-integrated scaffolds were compared to pristine scaffolds. The modified scaffolds showed swelling ratios, weight losses and mechanical properties similar to those of unmodified scaffolds. Finally, in vitro diffusional tests proved that the collagen scaffolds could stably retain the microcapsules over long incubation time in Tris-HCl buffer at 37°C without undergoing morphological changes, thus confirming their suitability for tissue engineering applications. The obtained results indicate that by tuning the charge of the microcapsules and by varying the fabrication conditions, collagen scaffolds patterned with high or low number of microcapsules can be obtained, and that the microcapsules-integrated scaffolds fully retain their original physical properties. PMID:27219851

  16. Path to Collagenolysis: COLLAGEN V TRIPLE-HELIX MODEL BOUND PRODUCTIVELY AND IN ENCOUNTERS BY MATRIX METALLOPROTEINASE-12.

    Science.gov (United States)

    Prior, Stephen H; Byrne, Todd S; Tokmina-Roszyk, Dorota; Fields, Gregg B; Van Doren, Steven R

    2016-04-01

    Collagenolysis is essential in extracellular matrix homeostasis, but its structural basis has long been shrouded in mystery. We have developed a novel docking strategy guided by paramagnetic NMR that positions a triple-helical collagen V mimic (synthesized with nitroxide spin labels) in the active site of the catalytic domain of matrix metalloproteinase-12 (MMP-12 or macrophage metalloelastase) primed for catalysis. The collagenolytically productive complex forms by utilizing seven distinct subsites that traverse the entire length of the active site. These subsites bury ∼1,080 Å(2)of surface area, over half of which is contributed by the trailing strand of the synthetic collagen V mimic, which also appears to ligate the catalytic zinc through the glycine carbonyl oxygen of its scissile G∼VV triplet. Notably, the middle strand also occupies the full length of the active site where it contributes extensive interfacial contacts with five subsites. This work identifies, for the first time, the productive and specific interactions of a collagen triple helix with an MMP catalytic site. The results uniquely demonstrate that the active site of the MMPs is wide enough to accommodate two strands from collagen triple helices. Paramagnetic relaxation enhancements also reveal an extensive array of encounter complexes that form over a large part of the catalytic domain. These transient complexes could possibly facilitate the formation of collagenolytically active complexes via directional Brownian tumbling. PMID:26887942

  17. Relationship among bone mineral density, collagen composition, and biomechanical properties of callus in the healing of osteoporotic fracture

    Institute of Scientific and Technical Information of China (English)

    SHEN Bin; MU Jian-xiong; PEI Fu-xing

    2007-01-01

    Objective: To study the change and relationship among bone mineral density (BMD), collagen composition and biomechanical properties of the callus in the healing process of osteoporotic fracture.Methods: The osteoporotic rat model and fracture model were established through bilateral ovariectomy(OVX) and osteotomy of the middle shaft of the right hind tibiae, respectively. Ninety female SD rats were randomly divided into OVX group and sham group. With the samples of blood and callus, roentgenoraphic and histological observation were performed for the assessment of the healing progress of the fracture, and the serum concentration of TRAP-5b, proportion of type Ⅰ collagen,BMD and biomechanical properties of the callus were measured.Results: The OVX group experienced a significant delay of fracture healing. The mean serum concentration of TRAP-5b of rats in the OVX group was much higher than that in the sham group after the operation (P < 0.05), but the difference at the same time point after fracture was smaller than that before fracture (P < 0.05 ). The BMD of the callus in both groups reached the peak value at the 6 th week after fracture while the proportion of the type Ⅰ collagen and the biomechanical strength reached the peak at the 8th week.Conclusions: The deficiency of estrogen after the ovariectomy could induce the up-regulation of the osteoclasts activities, whereas the potency of further activation after fracture was depressed. Although the synthesis of collagen together with its mineralization determines the biomechanical properties of new bone, the accumulation of collagen could be assessed as an index in the prediction of biomechanical strength of bones independent of the bone mineral deposition.

  18. The collagen microfibril model, a tool for biomaterials scientists

    Science.gov (United States)

    Animal hides, a major byproduct of the meat industry, are a rich source of collagen, a structural protein of the extracellular matrix that gives strength and form to the skin, tendons and bones of mammals. The structure of fibrous collagen, a long triple helix that self-associates in a staggered arr...

  19. Evaluation of bone matrix gelatin/fibrin glue and chitosan/gelatin composite scaffolds for cartilage tissue engineering.

    Science.gov (United States)

    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

  20. Characterization of fibrillar collagens and extracellular matrix of glandular benign prostatic hyperplasia nodules.

    Directory of Open Access Journals (Sweden)

    Tyler M Bauman

    Full Text Available Recent studies have associated lower urinary tract symptoms (LUTS in men with prostatic fibrosis, but a definitive link between collagen deposition and LUTS has yet to be demonstrated. The objective of this study was to evaluate ECM and collagen content within normal glandular prostate tissue and glandular BPH, and to evaluate the association of clinical parameters of LUTS with collagen content.Fibrillar collagen and ECM content was assessed in normal prostate (48 patients and glandular BPH nodules (24 patients using Masson's trichrome stain and Picrosirius red stain. Second harmonic generation (SHG imaging was used to evaluate collagen content. Additional BPH tissues (n = 47 were stained with Picrosirius red and the association between clinical parameters of BPH/LUTS and collagen content was assessed.ECM was similar in normal prostate and BPH (p = 0.44. Total collagen content between normal prostate and glandular BPH was similar (p = 0.27, but a significant increase in thicker collagen bundles was observed in BPH (p = 0.045. Using SHG imaging, collagen content in BPH (mean intensity = 62.52; SEM = 2.74 was significantly higher than in normal prostate (51.77±3.49; p = 0.02. Total collagen content was not associated with treatment with finasteride (p = 0.47 or α-blockers (p = 0.52, pre-TURP AUA symptom index (p = 0.90, prostate-specific antigen (p = 0.86, post-void residual (PVR; p = 0.32, prostate size (p = 0.21, or post-TURP PVR (p = 0.51. Collagen content was not associated with patient age in patients with BPH, however as men aged normal prostatic tissue had a decreased proportion of thick collagen bundles.The proportion of larger bundles of collagen, but not total collagen, is increased in BPH nodules, suggesting that these large fibers may play a role in BPH/LUTS. Total collagen content is independent of clinical parameters of BPH and LUTS. If fibrosis and overall ECM deposition are

  1. Human mandible bone defect repair by the grafting of dental pulp stem/progenitor cells and collagen sponge biocomplexes

    Directory of Open Access Journals (Sweden)

    R d’Aquino

    2009-11-01

    Full Text Available In this study we used a biocomplex constructed from dental pulp stem/progenitor cells (DPCs and a collagen sponge scaffold for oro-maxillo-facial (OMF bone tissue repair in patients requiring extraction of their third molars. The experiments were carried out according to our Internal Ethical Committee Guidelines and written informed consent was obtained from the patients. The patients presented with bilateral bone reabsorption of the alveolar ridge distal to the second molar secondary to impaction of the third molar on the cortical alveolar lamina, producing a defect without walls, of at least 1.5 cm in height. This clinical condition does not permit spontaneous bone repair after extraction of the third molar, and eventually leads to loss also of the adjacent second molar. Maxillary third molars were extracted first for DPC isolation and expansion. The cells were then seeded onto a collagen sponge scaffold and the obtained biocomplex was used to fill in the injury site left by extraction of the mandibular third molars. Three months after autologous DPC grafting, alveolar bone of patients had optimal vertical repair and complete restoration of periodontal tissue back to the second molars, as assessed by clinical probing and X-rays. Histological observations clearly demonstrated the complete regeneration of bone at the injury site. Optimal bone regeneration was evident one year after grafting. This clinical study demonstrates that a DPC/collagen sponge biocomplex can completely restore human mandible bone defects and indicates that this cell population could be used for the repair and/or regeneration of tissues and organs.

  2. D-Glucose as a modifying agent in gelatin/collagen matrix and reservoir nanoparticles for Calendula officinalis delivery.

    Science.gov (United States)

    Lam, P-L; Kok, S H-L; Bian, Z-X; Lam, K-H; Tang, J C-O; Lee, K K-H; Gambari, R; Chui, C-H

    2014-05-01

    Gelatin/Collagen-based matrix and reservoir nanoparticles require crosslinkers to stabilize the formed nanosuspensions, considering that physical instability is the main challenge of nanoparticulate systems. The use of crosslinkers improves the physical integrity of nanoformulations under the-host environment. Aldehyde-based fixatives, such as formaldehyde and glutaraldehyde, have been widely applied to the crosslinking process of polymeric nanoparticles. However, their potential toxicity towards human beings has been demonstrated in many previous studies. In order to tackle this problem, D-glucose was used during nanoparticle formation to stabilize the gelatin/collagen-based matrix wall and reservoir wall for the deliveries of Calendula officinalis powder and oil, respectively. In addition, therapeutic selectivity between malignant and normal cells could be observed. The C. officinalis powder loaded nanoparticles significantly strengthened the anti-cancer effect towards human breast adenocarcinoma MCF7 cells and human hepatoma SKHep1 cells when compared with the free powder. On the contrary, the nanoparticles did not show significant cytotoxicity towards normal esophageal epithelial NE3 cells and human skin keratinocyte HaCaT cells. On the basis of these evidences, D-glucose modified gelatin/collagen matrix nanoparticles containing C. officinalis powder might be proposed as a safer alternative vehicle for anti-cancer treatments. PMID:24657927

  3. Lysyl oxidases in idiopathic pulmonary fibrosis: A key participant in collagen I matrix remodelling

    NARCIS (Netherlands)

    Tjin, Gavin; Mahar, Annabelle; Kable, Eleanor; Burgess, Janette

    2015-01-01

    Introduction: The fibrotic element in Idiopathic Pulmonary Fibrosis (IPF) is a key feature and is associated with Usual Interstitial Pneumonia (UIP) pattern. Fibrillar collagen I (COL1) has second harmonic generation (SHG) properties, with signals both in the forward (F) (organized collagen) & backw

  4. Sulphur isotopic variation in ancient bone collagen from Europe: implications for human palaeodiet, residence mobility, and modern pollutant studies

    Science.gov (United States)

    Richards, M. P.; Fuller, B. T.; Hedges, R. E. M.

    2001-09-01

    We report here on the first measurements of δ 34S in small (animals ( n=4) from various European archaeological sites. Measurement of δ 34S values complement collagen δ 13C and δ 15N measurements and can provide corroboratory palaeodietary insights or new locality information. In areas where there are clear δ 34S differences between marine, freshwater and terrestrial ecosystems they can be used to infer the consumption of foods from these systems. Also, as collagen δ 34S values reflect local environment δ 34S values, they can be used to identify the region where an individual normally resides, and therefore identify migratory individuals. Modern animal bone collagen δ 34S values were also measured ( n=7) and it was observed that such values may be confounded by modern sulphur pollutants, and we propose that archaeological material, which is free from modern sulphur pollutants, would provide appropriate baseline material for ecosystem studies.

  5. Specifically decreased collagen biosynthesis in scurvy dissociated from an effect on proline hydroxylation and correlated with body weight loss. In vitro studies in guinea pig calvarial bones.

    OpenAIRE

    Chojkier, M.; Spanheimer, R.; Peterkofsky, B

    1983-01-01

    The question whether ascorbate regulates collagen production solely through its direct role in proline hydroxylation was investigated. Proteins in calvarial bones from control and scorbutic weanling guinea pigs were labeled in short-term cultures with radioactive proline. Proteins were digested with purified bacterial collagenase to distinguish between effects on collagen polypeptide production and hydroxyproline formation. There was a preferential decrease in the absolute rate of collagen bi...

  6. Structural and mechanical differences between collagen homo- and heterotrimers: relevance for the molecular origin of brittle bone disease.

    Science.gov (United States)

    Chang, Shu-Wei; Shefelbine, Sandra J; Buehler, Markus J

    2012-02-01

    Collagen constitutes one-third of the human proteome, providing mechanical stability, elasticity, and strength to organisms. Normal type I collagen is a heterotrimer triple-helical molecule consisting of two α-1 chains and one α-2 chain. The homotrimeric isoform of type I collagen, which consists of three α-1 chains, is only found in fetal tissues, fibrosis, and cancer in humans. A mouse model of the genetic brittle bone disease, osteogenesis imperfect, oim, is characterized by a replacement of the α-2 chain by an α-1 chain, resulting also in a homotrimer collagen molecule. Experimental studies of oim mice tendon and bone have shown reduced mechanical strength compared to normal mice. The relationship between the molecular content and the decrease in strength is, however, still unknown. Here, fully atomistic simulations of a section of mouse type I heterotrimer and homotrimer collagen molecules are developed to explore the effect of the substitution of the α-2 chain. We calculate the persistence length and carry out a detailed analysis of the structure to determine differences in structural and mechanical behavior between hetero- and homotrimers. The results show that homotrimer persistence length is half of that of the heterotrimer (96 Å vs. 215 Å), indicating it is more flexible and confirmed by direct mechanical testing. Our structural analyses reveal that in contrast to the heterotrimer, the homotrimer easily forms kinks and freely rotates with angles much larger than heterotrimer. These local kinks may explain the larger lateral distance between collagen molecules seen in the fibrils of oim mice tendon and could have implications for reducing the intermolecular cross-linking, which is known to reduce the mechanical strength. PMID:22325288

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

    Science.gov (United States)

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

    2013-06-01

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

  8. Xenogeneic collagen matrix for periodontal plastic surgery procedures: a systematic review and meta-analysis.

    Science.gov (United States)

    Atieh, M A; Alsabeeha, N; Tawse-Smith, A; Payne, A G T

    2016-08-01

    Several clinical trials describe the effectiveness of xenogeneic collagen matrix (XCM) as an alternative option to surgical mucogingival procedures for the treatment of marginal tissue recession and augmentation of insufficient zones of keratinized tissue (KT). The aim of this systematic review and meta-analysis was to evaluate the clinical and patient-centred outcomes of XCM compared to other mucogingival procedures. Applying guidelines of the Preferred Reporting Items for Systematic Reviews and Meta analyses statement, randomized controlled trials were searched for in electronic databases and complemented by hand searching. The risk of bias was assessed using the Cochrane Collaboration's Risk of Bias tool and data were analysed using statistical software. A total of 645 studies were identified, of which, six trials were included with 487 mucogingival defects in 170 participants. Overall meta-analysis showed that connective tissue graft (CTG) in conjunction with the coronally advanced flap (CAF) had a significantly higher percentage of complete/mean root coverage and mean recession reduction than XCM. Insufficient evidence was found to determine any significant differences in width of KT between XCM and CTG. The XCM had a significantly higher mean root coverage, recession reduction and gain in KT compared to CAF alone. No significant differences in patient's aesthetic satisfaction were found between XCM and CTG, except for postoperative morbidity in favour of XCM. Operating time was significantly reduced with the use of XCM compared with CTG but not with CAF alone. There is no evidence to demonstrate the effectiveness of XCM in achieving greater root coverage, recession reduction and gain in KT compared to CTG plus CAF. Superior short-term results in treating root coverage compared with CAF alone are possible. There is limited evidence that XCM may improve aesthetic satisfaction, reduce postoperative morbidity and shorten the operating time. Further long

  9. Adaptation of subchondral bone in osteoarthritis

    DEFF Research Database (Denmark)

    Ding, Ming

    2004-01-01

    never been proven. Recent studies showing reduced chemical and mechanical properties of subchondral bone in various stages of the disease have invigorated interest in the role of subchondral bone in the development and progression of the disease. The current study showed that the concept of bone...... adaptation might explain subchondral stiffening, a process where subchondral bone becomes typically sclerotic in osteoarthritis. In addition, we report reduced mechanical matrix tissue properties as well as an increase in denatured collagen content. In conclusion, although osteoarthritic bone tissue contains...... increased denatured collagen and has reduced matrix mechanical properties, the widely accepted concept of subchondral stiffening is compatible with the process of normal bone adaptation. Udgivelsesdato: 2004...

  10. Toward guided tissue and bone regeneration: morphology, attachment, proliferation, and migration of cells cultured on collagen barrier membranes. A systematic review.

    NARCIS (Netherlands)

    Behring, J.; Junker, R.; Walboomers, X.F.; Chessnut, B.; Jansen, J.A.

    2008-01-01

    Collagen barrier membranes are frequently used in both guided tissue regeneration (GTR) and guided bone regeneration (GBR). Collagen used for these devices is available from different species and is often processed to alter the properties of the final product. This is necessary because unprocessed c

  11. Multiple myeloma: Changes in serum C-terminal telopeptide of collagen type I and bone-specific alkaline phosphatase can be used in daily practice to detect imminent osteolysis

    DEFF Research Database (Denmark)

    Lund, Thomas; Abildgaard, Niels; Andersen, Thomas L;

    2010-01-01

    of collagen type-I (CTX-I), C-terminal crosslinked telopeptide of type-I collagen generated by MMPs (ICTP), N-terminal crosslinked telopeptide of type-I collagen (NTX-I), and the bone formation marker bone-specific alkaline phosphatase (bALP) monthly for two years. Retrospectively, we identified 40 cases...

  12. Synergistic intrafibrillar/extrafibrillar mineralization of collagen scaffolds based on a biomimetic strategy to promote the regeneration of bone defects

    OpenAIRE

    Wang Y; Van Manh H; Wang H; Zhong X; Zhang X; Li C

    2016-01-01

    Yao Wang,1 Ngo Van Manh,1,2 Haorong Wang,1 Xue Zhong,1 Xu Zhang,1 Changyi Li1 1School of Dentistry, Hospital of Stomatology, Tianjin Medical University, Tianjin, People’s Republic of China; 2Thaibinh University of Medicine and Pharmacy, Thaibinh, Vietnam Abstract: The mineralization of collagen scaffolds can improve their mechanical properties and biocompatibility, thereby providing an appropriate microenvironment for bone regeneration. The primary purpose of the present study is ...

  13. Preparation and Characterization of a Collagen-Liposome-Chondroitin Sulfate Matrix with Potential Application for Inflammatory Disorders Treatment

    Directory of Open Access Journals (Sweden)

    Oana Craciunescu

    2014-01-01

    Full Text Available Smart drug delivery systems with controllable properties play an important role in targeted therapy and tissue regeneration. The aim of our study was the preparation and in vitro evaluation of a collagen (Col matrix embedding a liposomal formulation of chondroitin sulfate (L-CS for the treatment of inflammatory disorders. Structural studies using Oil Red O specific staining for lipids and scanning electron microscopy showed an alveolar network of nanosized Col fibrils decorated with deposits of L-CS at both periphery and inner of the matrix. The porosity and density of Col-L-CS matrix were similar to those of Col matrix, while its mean pore size and biodegradability had significantly higher and lower values (P<0.05, respectively. In vitro cytotoxicity assays showed that the matrix system induced high cell viability and stimulated cell metabolism in L929 fibroblast cell culture. Light and electron micrographs of the cell-matrix construct showed that cells clustered into the porous structure at 72 h of cultivation. In vitro diffusion test indicated that the quantity of released CS was significantly lower (P<0.05 after embedment of L-CS within Col matrix. All these results indicated that the biocompatible and biodegradable Col-L-CS matrix might be a promising delivery system for local treatment of inflamed site.

  14. Bone

    International Nuclear Information System (INIS)

    Bone scanning provides information on the extent of primary bone tumors, on possible metastatic disease, on the presence of osteomyelitis prior to observation of roentgenographic changes so that earlier therapy is possible, on the presence of collagen diseases, on the presence of fractures not disclosed by x-ray films, and on the evaluation of aseptic necrosis. However, the total effect and contribution of bone scanning to the diagnosis, treatment, and ultimate prognosis of pediatric skeletal diseases is, as yet, unknown. (auth)

  15. Paleoecological and climatic implications of stable isotope results from late Pleistocene bone collagen, Ziegeleigrube Coenen, Germany

    Science.gov (United States)

    Wißing, Christoph; Matzerath, Simon; Turner, Elaine; Bocherens, Hervé

    2015-07-01

    Climatic and ecological conditions during Marine Oxygen Isotope Stage (MIS) 3 are complex and the impact of cold spells on the ecosystems in Central Europe still needs to be investigated thoroughly. Ziegeleigrube Coenen (ZC) is a late Pleistocene MIS 3 locality in the Lower Rhine Embayment of Germany, radiocarbon-dated to > 34 14C ka BP. The site yielded a broad spectrum of mammal species. We investigated the carbon (δ13C), nitrogen (δ15N) and sulfur (δ34S) isotope signatures of bone collagen, since these are valuable tools in characterizing ecological niches, environmental conditions and aspects of climate and mobility. By comparison with pre- and post-Last Glacial Maximum (LGM) sites in Central Europe we show that ZC belongs in a cold event of MIS 3 and was climatically more similar to post-LGM sites than to pre-LGM sites. However, the trophic structure resembled that of typical pre-LGM sites in Belgium. This cold event in MIS 3 changed the bottom of the foodweb, but do not seem to have had a direct impact on the occurrence of the mammalian species and their ecological distribution. Apparently the (mega-) faunal community could adapt also to harsher environmental conditions during MIS 3.

  16. Highlighting the impact of aging on type I collagen: label-free investigation using confocal reflectance microscopy and diffuse reflectance spectroscopy in 3D matrix model.

    Science.gov (United States)

    Guilbert, Marie; Roig, Blandine; Terryn, Christine; Garnotel, Roselyne; Jeannesson, Pierre; Sockalingum, Ganesh D; Manfait, Michel; Perraut, François; Dinten, Jean-Marc; Koenig, Anne; Piot, Olivier

    2016-02-23

    During aging, alterations of extracellular matrix proteins contribute to various pathological phenotypes. Among these alterations, type I collagen cross-linking and associated glycation products accumulation over time detrimentally affects its physico-chemical properties, leading to alterations of tissue biomechanical stability. Here, different-age collagen 3D matrices using non-destructive and label-free biophotonic techniques were analysed to highlight the impact of collagen I aging on 3D constructs, at macroscopic and microscopic levels. Matrices were prepared with collagens extracted from tail tendons of rats (newborns, young and old adults) to be within the physiological aging process. The data of diffuse reflectance spectroscopy reveal that aging leads to an inhibition of fibril assembly and a resulting decrease of gel density. Investigations by confocal reflectance microscopy highlight poor-fibrillar structures in oldest collagen networks most likely related to the glycation products accumulation. Complementarily, an infrared analysis brings out marked spectral variations in the Amide I profile, specific of the peptidic bond conformation and for carbohydrates vibrations as function of collagen-age. Interestingly, we also highlight an unexpected behavior for newborn collagen, exhibiting poorly-organized networks and microscopic features close to the oldest collagen. These results demonstrate that changes in collagen optical properties are relevant for investigating the incidence of aging in 3D matrix models.

  17. Use of carboxymethyl cellulose and collagen carrier with equine bone lyophilisate suggests late onset bone regenerative effect in a humerus drill defect - a pilot study in six sheep

    DEFF Research Database (Denmark)

    Jensen, Jonas; Foldager, Casper Bindzus; Jakobsen, Thomas Vestergaard;

    2010-01-01

    the osteoinductive stimulus throughout the bone defect. Six sheep underwent a bilateral humerus drill defect. The drill hole was filled with a compound consisting of 100 mg CMC, 100 mg collagen powder, and 1 ccm autologous full blood in one side, and a combination of this filler compound and 20 mg Colloss E...... in the other. The animals were divided into three groups of two animals and observed for 8, 12 and 16 weeks. Drill holes was evaluated using quantitative computed tomography (QCT), micro computed tomography (microCT) and histomorphometry. Mean total bone mineral density (BMD) of each implantation site...... was calculated with both QCT and microCT. Bone volume to total volume (BV/TV) was analyzed using microCT and histomorphometry. Although not statistically significant, results showed increased bone BMD after 16 weeks in microCT data and an increased BV/TV after 16 weeks in both microCT and histology. Correlation...

  18. Myeloid-derived suppressor cells contribute to bone erosion in collagen-induced arthritis by differentiating to osteoclasts.

    Science.gov (United States)

    Zhang, Hui; Huang, Yuefang; Wang, Shuang; Fu, Rong; Guo, Chaohuan; Wang, Hongyue; Zhao, Jijun; Gaskin, Felicia; Chen, Jingxian; Yang, Niansheng; Fu, Shu Man

    2015-12-01

    Bone erosion is a sign of severe rheumatoid arthritis and osteoclasts play a major role in the bone resorption. Recently, myeloid-derived suppressor cells (MDSC) has been reported to be increased in collagen-induced arthritis (CIA). The number of circulating MDSCs is shown to correlate with rheumatoid arthritis. These findings suggest that MDSCs are precursor cells involved in bone erosion. In this study, MDSCs isolated from mice with CIA stimulated with M-CSF and RANKL in vitro expressed osteoclast markers and acquired osteoclast bone resorption function. MDSCs sorted from CIA mice were transferred into the tibia of normal DBA/1J mice and bones were subjected to histological and Micro CT analyses. The transferred CIA-MDSCs were shown to differentiate into TRAP(+) osteoclasts that were capable of bone resorption in vivo. MDSCs isolated from normal mice had more potent suppressor activity and much less capability to differentiate to osteoclast. Additional experiments showed that NF-κB inhibitor Bay 11-7082 or IκB inhibitor peptide blocked the differentiation of MDSCs to osteoclast and bone resorption. IL-1Ra also blocked this differentiation. In contrast, the addition of IL-1α further enhanced osteoclast differentiation and bone resorption. These results suggest that MDSCs are a source of osteoclast precursors and inflammatory cytokines such as IL-1, contributing significantly to erosive changes seen in rheumatoid arthritis and related disorders.

  19. Reduced serum content and increased matrix stiffness promote the cardiac myofibroblast transition in 3D collagen matrices.

    Science.gov (United States)

    Galie, Peter A.; Westfall, Margaret V.; Stegemann, Jan P.

    2011-01-01

    Introduction The fibroblast-myofibroblast transition is an important event in the development of cardiac fibrosis and scar formation initiated after myocardial ischemia. The goals of the present study were to better understand the contribution of environmental factors to this transition and determine whether myofibroblasts provide equally important feedback to the surrounding environment. Methods The influence of matrix stiffness and serum concentration on the myofibroblast transition was assessed by measuring message levels of a panel of cardiac fibroblast phenotype markers using quantitative rtPCR. Cell-mediated gel compaction measured the influence of environmental factors on cardiac fibroblast contractility. Immunohistochemistry characterized α-SMA expression and cell morphology, while static and dynamic compression testing evaluated the effect of the cell response on the mechanical properties of the cell-seeded collagen hydrogels. Results Both reduced serum content and increased matrix stiffness contributed to the myofibroblast transition, as indicated by contractile compaction of the gels, increased message levels of col3α1 and α-SMA, and a less stellate morphology. However, the effects of serum and matrix stiffness were not additive. Mechanical testing indicated the cell-seeded gels became less viscoelastic with time, and that reduced serum content also increased the initial elastic properties of the gel. Conclusions The results suggest that reduced serum and increased matrix stiffness promote the myofibroblast phenotype in the myocardium. This transition both enhances and is promoted by matrix stiffness, indicating the presence of positive feedback that may contribute to the pathogenesis of cardiac fibrosis. Summary Lower serum content and increased matrix stiffness accelerated the transition of cardiac fibroblasts seeded in collagen hydrogels to a myofibroblast phenotype, though their effects were not additive. Reduced serum also affected mechanical

  20. Biological Safety of Fish (Tilapia) Collagen

    OpenAIRE

    Yamamoto, Kohei; Igawa, Kazunari; Sugimoto, Kouji; Yoshizawa, Yuu; Yanagiguchi, Kajiro; Ikeda, Takeshi; Yamada, Shizuka; Hayashi, Yoshihiko

    2014-01-01

    Marine collagen derived from fish scales, skin, and bone has been widely investigated for application as a scaffold and carrier due to its bioactive properties, including excellent biocompatibility, low antigenicity, and high biodegradability and cell growth potential. Fish type I collagen is an effective material as a biodegradable scaffold or spacer replicating the natural extracellular matrix, which serves to spatially organize cells, providing them with environmental signals and directing...

  1. Biological Safety of Fish (Tilapia) Collagen

    OpenAIRE

    山本, 耕平

    2015-01-01

    Marine collagen derived from fish scales, skin, and bone has been widely investigated for application as a scaffold and carrier due to its bioactive properties, including excellent biocompatibility, low antigenicity, and high biodegradability and cell growth potential. Fish type I collagen is an effective material as a biodegradable scaffold or spacer replicating the natural extracellular matrix, which serves to spatially organize cells, providing them with environmental signals and directing...

  2. Promotion of Hepatic Differentiation of Bone Marrow Mesenchymal Stem Cells on Decellularized Cell-Deposited Extracellular Matrix

    Directory of Open Access Journals (Sweden)

    Hongliang He

    2013-01-01

    Full Text Available Interactions between stem cells and extracellular matrix (ECM are requisite for inducing lineage-specific differentiation and maintaining biological functions of mesenchymal stem cells by providing a composite set of chemical and structural signals. Here we investigated if cell-deposited ECM mimicked in vivo liver's stem cell microenvironment and facilitated hepatogenic maturation. Decellularization process preserved the fibrillar microstructure and a mix of matrix proteins in cell-deposited ECM, such as type I collagen, type III collagen, fibronectin, and laminin that were identical to those found in native liver. Compared with the cells on tissue culture polystyrene (TCPS, bone marrow mesenchymal stem cells (BM-MSCs cultured on cell-deposited ECM showed a spindle-like shape, a robust proliferative capacity, and a suppressed level of intracellular reactive oxygen species, accompanied with upregulation of two superoxide dismutases. Hepatocyte-like cells differentiated from BM-MSCs on ECM were determined with a more intensive staining of glycogen storage, an elevated level of urea biosynthesis, and higher expressions of hepatocyte-specific genes in contrast to those on TCPS. These results demonstrate that cell-deposited ECM can be an effective method to facilitate hepatic maturation of BM-MSCs and promote stem-cell-based liver regenerative medicine.

  3. Infection by Toxoplasma gondii Induces Amoeboid-Like Migration of Dendritic Cells in a Three-Dimensional Collagen Matrix.

    Directory of Open Access Journals (Sweden)

    Sachie Kanatani

    Full Text Available Toxoplasma gondii, an obligate intracellular parasite of humans and other warm-blooded vertebrates, invades a variety of cell types in the organism, including immune cells. Notably, dendritic cells (DCs infected by T. gondii acquire a hypermigratory phenotype that potentiates parasite dissemination by a 'Trojan horse' type of mechanism in mice. Previous studies have demonstrated that, shortly after parasite invasion, infected DCs exhibit hypermotility in 2-dimensional confinements in vitro and enhanced transmigration in transwell systems. However, interstitial migration in vivo involves interactions with the extracellular matrix in a 3-dimensional (3D space. We have developed a collagen matrix-based assay in a 96-well plate format that allows quantitative locomotion analyses of infected DCs in a 3D confinement over time. We report that active invasion of DCs by T. gondii tachyzoites induces enhanced migration of infected DCs in the collagen matrix. Parasites of genotype II induced superior DC migratory distances than type I parasites. Moreover, Toxoplasma-induced hypermigration of DCs was further potentiated in the presence of the CCR7 chemotactic cue CCL19. Blocking antibodies to integrins (CD11a, CD11b, CD18, CD29, CD49b insignificantly affected migration of infected DCs in the 3D matrix, contrasting with their inhibitory effects on adhesion in 2D assays. Morphological analyses of infected DCs in the matrix were consistent with the acquisition of an amoeboid-like migratory phenotype. Altogether, the present data show that the Toxoplasma-induced hypermigratory phenotype in a 3D matrix is consistent with integrin-independent amoeboid DC migration with maintained responsiveness to chemotactic and chemokinetic cues. The data support the hypothesis that induction of amoeboid hypermigration and chemotaxis/chemokinesis in infected DCs potentiates the dissemination of T. gondii.

  4. Early adhesive behavior of bone-marrow-derived mesenchymal stem cells on collagen electrospun fibers

    Energy Technology Data Exchange (ETDEWEB)

    Chan, Casey K; Liao, Susan; Lareu, Ricky R; Raghunath, Michael [Division of Bioengineering, National University of Singapore, 7 Engineering Drive 1, Singapore 117574 (Singapore); Li, Bojun; Ramakrishna, S [Nanoscience and Nanotechnology Initiative, National University of Singapore, 2 Engineering Drive 3, Singapore 117576 (Singapore); Larrick, James W, E-mail: doschanc@nus.edu.s [Panorama Research Institute, 2462 Wyandotte Street, Mountain View, CA 94043 (United States)

    2009-06-15

    A bioabsorbable nanofibrous scaffold was developed for early adhesion of mesenchymal stem cells (MSCs). Collagen nanofibers with diameters of 430 +- 170 nm were fabricated by electrospinning. Over 45% of the MSC population adhered to this collagen nanofiber after 30 min at room temperature. Remarkably, collagen-coated P(LLA-CL) electrospun nanofibers were almost as efficient as collagen nanofibers whereas collagen cast film did not enhance early capture when it was applied on cover slips. The adhesive efficiency could be further increased to over 20% at 20 min and over 55% at 30 min when collagen nanofibers were grafted with monoclonal antibodies recognizing CD29 or CD49a. These data demonstrate that the early adhesive behavior is highly dependent on both the surface texture and the surface chemistry of the substrate. These findings have potential applications for early capture of MSCs in an ex vivo setting under time constraints such as in a surgical setting.

  5. Repair of radius defect with bone-morphogenetic-protein loaded hydroxyapatite/collagen-poly(L-lactic acid) composite

    Institute of Scientific and Technical Information of China (English)

    胡蕴玉; 张超; 吕荣; 徐建强; 李丹

    2003-01-01

    Objective: To explore the method to repair bone defect with bone-morphogenetic-protein loaded hydroxyapatite/collagen-poly(L-lactic acid) composite. Methods: 18 adult beagle dogs were randomly divided into 3 groups. In Group A, bone-morphogenetic-protein (BMP) loaded hydroxyapatite/collagen-poly(L-lactic acid) (HAC-PLA) scaffold was implanted in a 2 cm diaphyseal defect in the radius. In Group B, unloaded pure HAC-PLA scaffold was implanted in the defects. No material was implanted in Group C (control group). The dogs were sacrificed 6 months postoperatively. Features of biocompatibility, biodegradability and osteoinduction were evaluated with histological, radiological examinations and bone mineral density (BMD) measurements.Results: In Group A, the radius defect healed after the treatment with BMP loaded HAC-PLA. BMD at the site of the defect was higher than that of the contralateral radius. Fibrous union developed in the animals of the control group. Conclusions: BMP not only promotes osteogenesis but also accelerates degradation of the biomaterials. Optimized design parameters of a three-dimensional porous biomaterial would give full scope to the role of BMP as an osteoinductive growth factor.

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

    Science.gov (United States)

    Deng, Meng

    characterized for miscibility, mechanical properties, degradation kinetics, and in vitro osteocompatibility. Primary rat osteoblasts (PRO) isolated from rat calvaria were used to evaluate their in vitro osteocompatibility. The blends were also characterized for in vivo biodegradability and biocompatibility using a rat subcutaneous implantation model. Successful in vivo scaffold-based tissue regeneration greatly depends on the scaffold material biocompatibility, mechanical stability, and scaffold architecture to promote tissue in-growth. The other part of the work in the dissertation is focused on the development of mechanically competent bioresorbable nano-structured three-dimensional (3D) hiomimetic scaffolds for bone tissue engineering applications. Scaffold material selection was based on achieving improved mechanical stability, in vitro osteoblast performance, and in vivo biocompatibility. A miscible PNGEGPhPh-PLAGA blend system developed and characterized in the first part of the thesis work was chosen to fabricate a nanofiber-based mechanically competent biomimetic scaffold via electrospinning. Due to its versatility, controllability and reproducibility, the technique of electrospinning was adopted to produce blend nanofibers. The polymer solution concentration and electrospinning parameters were optimized to produce blend fibers in the range of 50-500 nm to mimic dimensions of collagen fibrils present in the natural extracellular matrix of native bone. These blend nanofiber matrices supported PRO adhesion, proliferation and showed an elevated phenotype expression compared to PLAGA nanofibers. Orienting electrospun nanofibers in a concentric manner with an open central cavity created a mechanically competent 3D scaffold mimicking the bone marrow cavity, as well as, the lamellar structure of bone. The 3D biomimetic scaffold exhibited a similar characteristic mechanical behavior to that of native bone. Compressive modulus of the scaffold was found to be within the range of

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

    Science.gov (United States)

    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

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

    Science.gov (United States)

    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.

  9. ICTP in Bone Metastases of Lung Cancer

    OpenAIRE

    Franjević, Ana; Pavićević, Radomir; Bubanović, Gordana

    2011-01-01

    Bone metastases often appear in advanced stages of lung cancer. They are the result of modulation of bone metabolism by tumor cells that migrated into bone microenvironment and degraded bone organic matrix. Measurement of C-terminal telopeptide of type I collagen (ICTP) in the serum of subjects with lung cancer with and without bone metastases and healthy population is the way to explore bone resorption. In 343 subjects included in this research ICTP level was significantly higher...

  10. Combined Effect of a Microporous Layer and Type I Collagen Coating on a Biphasic Calcium Phosphate Scaffold for Bone Tissue Engineering

    Directory of Open Access Journals (Sweden)

    Mun-Hwan Lee

    2015-03-01

    Full Text Available In this study, type I collagen was coated onto unmodified and modified microporous biphasic calcium phosphate (BCP scaffolds. Surface characterization using a scanning electron microscope (SEM and a surface goniometer confirmed the modification of the BCP coating. The quantity of the collagen coating was investigated using Sirius Red staining, and quantitative assessment of the collagen coating showed no significant differences between the two groups. MG63 cells were used to evaluate cell proliferation and ALP activity on the modified BCP scaffolds. The modified microporous surfaces showed low contact angles and large surface areas, which enhanced cell spreading and proliferation. Coating of the BCP scaffolds with type I collagen led to enhanced cell-material interactions and improved MG63 functions, such as spreading, proliferation, and differentiation. The micropore/collagen-coated scaffold showed the highest rate of cell response. These results indicate that a combination of micropores and collagen enhances cellular function on bioengineered bone allograft tissue.

  11. Differential effects of bone morphogenetic protein-2 and transforming growth factor-beta1 on gene expression of collagen-modifying enzymes in human adipose tissue-derived mesenchymal stem cells.

    Science.gov (United States)

    Knippenberg, Marlene; Helder, Marco N; Doulabi, Behrouz Zandieh; Bank, Ruud A; Wuisman, Paul I J M; Klein-Nulend, Jenneke

    2009-08-01

    Adipose tissue-derived mesenchymal stem cells (AT-MSCs) in combination with bone morphogenetic protein-2 (BMP-2) or transforming growth factor-beta1 (TGF-beta1) are under evaluation for bone tissue engineering. Posttranslational modification of type I collagen is essential for functional bone tissue with adequate physical and mechanical properties. We investigated whether BMP-2 (10-100 ng/mL) and/or TGF-beta1 (1-10 ng/mL) affect gene expression of alpha2(I) procollagen and collagen-modifying enzymes, that is, lysyl oxidase and lysyl hydroxylases 1, 2, and 3 (encoded by PLOD1, 2, and 3), by human AT-MSCs. BMP-2, but not TGF-beta1, increased alkaline phosphatase activity after 28 days, indicating osteogenic differentiation of AT-MSCs. At day 4, both BMP-2 and TGF-beta1 upregulated alpha2(I) procollagen and PLOD1, which was downregulated at day 28. TGF-beta1, but not BMP-2, downregulated PLOD3 at day 28. Lysyl oxidase was upregulated by TGF-beta1 at day 4 and by BMP-2 at day 7. Neither BMP-2 nor TGF-beta1 affected PLOD2. In conclusion, these results suggest that AT-MSCs differentially respond to BMP-2 and TGF-beta1 with changes in gene expression of collagen-modifying enzymes. AT-MSCs may thus be able to appropriately modify type I collagen to form a functional bone extracellular matrix for tissue engineering, dependent on the growth factor added. PMID:19231972

  12. Applicability of equine hydroxyapatite collagen (eHAC) bone blocks for lateral augmentation of the alveolar crest. A histological and histomorphometric analysis in rats

    NARCIS (Netherlands)

    Zecha, P. J.; Schortinghuis, J.; van der Wal, J. E.; Nagursky, H.; van den Broek, K. C.; Sauerbier, S.; Vissink, A.; Raghoebar, G. M.

    2011-01-01

    This study assessed the mechanical characteristics, biocompatibility and osteoconductive properties of an equine hydroxyapatite collagen (eHAC) bone block when applied as a bone substitute for lateral augmentation of rat mandible. 96 rats underwent lateral augmentation of the mandible, using two sub

  13. Autoradiographic study of the effect of 1,25-dihydroxyvitamin D3 on bone matrix synthesis in vitamin D replete rats

    International Nuclear Information System (INIS)

    An autoradiographic technique using pulse labels of [3H]proline was developed to assess the early effects of 1,25-dihydroxyvitamin D3 [1,25(OH)2D3] on bone matrix synthesis in vitamin D replete rats. Rats, 7 days old, were given 0.25, 2.5, or 25 ng of 1,25(OH)2D3 or vehicle alone subcutaneously on days 1, 3, and 5 of the experiment. Rats received a subcutaneous injection of 100 μCi [3H]proline on days 2 and 6 and were killed on day 7. Calvaria and tibia were processed for autoradiography, and morphometric methods were developed to measure the rate and amount of bone matrix formed during the experimental period. When compared to control values, the amount and rate of formation of new bone matrix were both significantly decreased in rats receiving 25 ng of 1,25(OH)2D3 and slightly, but not significantly, decreased in rats receiving 2.5 ng. We conclude that administration of pharmacologic doses of 1,25(OH)2D3 to vitamin D replete rat pups impairs the formation of collagenous bone matrix. (orig.)

  14. A calcium-collagen chelate dietary supplement attenuates bone loss in postmenopausal women with osteopenia: a randomized controlled trial.

    Science.gov (United States)

    Elam, Marcus L; Johnson, Sarah A; Hooshmand, Shirin; Feresin, Rafaela G; Payton, Mark E; Gu, Jennifer; Arjmandi, Bahram H

    2015-03-01

    Menopause leads to an increased risk for osteoporosis in women. Although drug therapies exist, increasing numbers of people prefer alternative therapies such as dietary supplements, for example, calcium, vitamin D, and collagen hydrolysates for the prevention and treatment of osteoporosis. We have previously shown that a 3-month intervention using a calcium-collagen chelate (CC) dietary supplement was efficacious in improving bone mineral density (BMD) and blood biomarkers of bone turnover in osteopenic postmenopausal women. This study reports the long-term efficacy of CC in reducing bone loss in postmenopausal women with osteopenia. Thirty-nine women were randomly assigned to one of two groups: 5 g of CC containing 500 mg of elemental calcium and 200 IU vitamin D (1,25-dihydroxyvitamin D3) or control (500 mg of calcium and 200 IU vitamin D) daily for 12 months. Total body, lumbar, and hip BMD were evaluated at baseline, 6 and 12 months using dual-energy X-ray absorptiometry. Blood was collected at baseline, 6 and 12 months to assess levels of blood biomarkers of bone turnover. Intent-to-treat (ITT) analysis was performed using repeated measures analysis of variance pairwise comparisons and multivariate analysis to assess time and group interactions. The loss of whole body BMD in women taking CC was substantially lower than that of the control group at 12 months in those who completed the study and the ITT analysis, respectively (CC: -1.33% and -0.33% vs. control: -3.75% and -2.17%; P=.026, P=.035). The CC group had significantly reduced levels of sclerostin and tartrate-resistant acid phosphatase isoform 5b (TRAP5b) (P<.05), and higher bone-specific alkaline phosphatase/TRAP5b ratio (P<.05) than control at 6 months. These results support the use of CC in reducing bone loss in osteopenic postmenopausal women.

  15. The effect of stromelysin-1 (MMP-3) on non-collagenous extracellular matrix proteins of demineralized dentin and the adhesive properties of restorative resins

    NARCIS (Netherlands)

    T. Boukpessi; S. Menashi; L. Camoin; J.M. ten Cate; M. Goldberg; C. Chaussain-Miller

    2008-01-01

    Dentin non-collagenous matrix components (NCPs) are structural proteins involved in the formation, the architecture and the mineralization of the extracellular matrix (ECM). We investigated here how recombinant metalloproteinase stromelysin-1, also termed MMP-3, initiates the release of ECM molecule

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

    Science.gov (United States)

    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.

  17. Bone Quality: The Mechanical Effects of Microarchitecture and Matrix Properties

    NARCIS (Netherlands)

    J.S. Day (Judd)

    2005-01-01

    textabstractIn this body of work we have examined some of the current concepts pertaining to the relation between bone mass, bone quality and the mechanical properties of bone. In our first series of studies we used a model of human osteoarthritis to investigate the implications of changes in the ef

  18. Ectopic Bone Formation in vivo Induced by a Novel Synthetic Peptide Derived from BMP-2 Using Porous Collagen Scaffolds

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    To investigate the osteoinductive and ectopicly osteogenic effects of a novel peptide P24 derived from bone morphogenetic protein 2 (BMP2), biodegradable collagen scaffolds (CS) were used to load BMP-2-derived peptide solutions with different concentrations (0.4 mg peptide/CS, 0.1 mg peptide/CS and pure CS, respectively), and the implants were implanted into muscular pockets on the back of Wistar rats.Radiographs and histological analysis were performed to evaluate the ectopic bone effects. Active ectopic bone formation was seen in both groups containing the peptide at different concentration (0.4 mg and 0.1 mg),whereas no bone formation and only fibrous tissue was seen in the pure CS group. The new bone formation induced by the peptide P24 displayed a dose-dependent and time-dependent efficiency. The new bone formation in the 0.4 mg peptide/CS group significantly increased than that of the 0.1 mg peptide/CS group. This novel BMP-2-derived peptide had excellent osteoinductive and ectopicly osteogenic properties which were similar to those of BMP2.

  19. Bioceramic-collagen scaffolds loaded with human adipose-tissue derived stem cells for bone tissue engineering.

    Science.gov (United States)

    Daei-Farshbaf, Neda; Ardeshirylajimi, Abdolreza; Seyedjafari, Ehsan; Piryaei, Abbas; Fadaei Fathabady, Fatemeh; Hedayati, Mehdi; Salehi, Mohammad; Soleimani, Masoud; Nazarian, Hamid; Moradi, Sadegh-Lotfalah; Norouzian, Mohsen

    2014-02-01

    The combination of bioceramics and stem cells has attracted the interest of research community for bone tissue engineering applications. In the present study, a combination of Bio-Oss(®) and type 1 collagen gel as scaffold were loaded with human adipose-tissue derived mesenchymal stem cells (AT-MSCs) after isolation and characterization, and the capacity of them for bone regeneration was investigated in rat critical size defects using digital mammography, multi-slice spiral computed tomography imaging and histological analysis. 8 weeks after implantation, no mortality or sign of inflammation was observed in the site of defect. According to the results of imaging analysis, a higher level of bone regeneration was observed in the rats receiving Bio-Oss(®)-Gel compared to untreated group. In addition, MSC-seeded Bio-Oss-Gel induced the highest bone reconstruction among all groups. Histological staining confirmed these findings and impressive osseointegration was observed in MSC-seeded Bio-Oss-Gel compared with Bio-Oss-Gel. On the whole, it was demonstrated that combination of AT-MSCs, Bio-Oss and Gel synergistically enhanced bone regeneration and reconstruction and also could serve as an appropriate structure to bone regenerative medicine and tissue engineering application.

  20. Amino acid delta13C analysis of hair proteins and bone collagen using liquid chromatography/isotope ratio mass spectrometry: paleodietary implications from intra-individual comparisons

    DEFF Research Database (Denmark)

    Raghavan, Maanasa; McCullagh, James S O; Lynnerup, Niels;

    2010-01-01

    We report a novel method for the chromatographic separation and measurement of stable carbon isotope ratios (delta(13)C) of individual amino acids in hair proteins and bone collagen using the LC-IsoLink system, which interfaces liquid chromatography (LC) with isotope ratio mass spectrometry (IRMS......). This paper provides baseline separation of 15 and 13 of the 18 amino acids in bone collagen and hair proteins, respectively. We also describe an approach to analysing small hair samples for compound-specific analysis of segmental hair sections. The LC/IRMS method is applied in a historical context...... by the delta(13)C analysis of hair proteins and bone collagen recovered from six individuals from Uummannaq in Greenland. The analysis of hair and bone amino acids from the same individual, compared for the first time in this study, is of importance in palaeodietary reconstruction. If hair proteins can be used...

  1. Fibrillar collagen I matrix remodelling in idiopathic pulmonary fibrosis: Are lysyl oxidases responsible?

    NARCIS (Netherlands)

    Tjin, G.; Jegathees, T.; Mahar, A.; Kable, E.P.W.; Burgess, J.K.

    2015-01-01

    Rationale: The development of fibrosis in Idiopathic Pulmonary Fibrosis (IPF) is a key feature and challenge in the treatment of the disease. The mechanisms of collagen I (COL1) reorganisation in the development of fibrosis, which may alter the stiffness of the tissue, are not well understood. Fibri

  2. Collagen in Human Tissues: Structure, Function, and Biomedical Implications from a Tissue Engineering Perspective

    Science.gov (United States)

    Balasubramanian, Preethi; Prabhakaran, Molamma P.; Sireesha, Merum; Ramakrishna, Seeram

    The extracellular matrix is a complex biological structure encoded with various proteins, among which the collagen family is the most significant and abundant of all, contributing 30-35% of the whole-body protein. "Collagen" is a generic term for proteins that forms a triple-helical structure with three polypeptide chains, and around 29 types of collagen have been identified up to now. Although most of the members of the collagen family form such supramolecular structures, extensive diversity exists between each type of collagen. The diversity is not only based on the molecular assembly and supramolecular structures of collagen types but is also observed within its tissue distribution, function, and pathology. Collagens possess complex hierarchical structures and are present in various forms such as collagen fibrils (1.5-3.5 nm wide), collagen fibers (50-70 nm wide), and collagen bundles (150-250 nm wide), with distinct properties characteristic of each tissue providing elasticity to skin, softness of the cartilage, stiffness of the bone and tendon, transparency of the cornea, opaqueness of the sclera, etc. There exists an exclusive relation between the structural features of collagen in human tissues (such as the collagen composition, collagen fibril length and diameter, collagen distribution, and collagen fiber orientation) and its tissue-specific mechanical properties. In bone, a transverse collagen fiber orientation prevails in regions of higher compressive stress whereas longitudinally oriented collagen fibers correlate to higher tensile stress. The immense versatility of collagen compels a thorough understanding of the collagen types and this review discusses the major types of collagen found in different human tissues, highlighting their tissue-specific uniqueness based on their structure and mechanical function. The changes in collagen during a specific tissue damage or injury are discussed further, focusing on the many tissue engineering applications for

  3. Suppression of α Smooth Muscle Actin Accumulation by Bovine Fetal Dermal Collagen Matrix in Full Thickness Skin Wounds.

    Science.gov (United States)

    Lineaweaver, William; Bush, Katie; James, Kenneth

    2015-06-01

    The suppression of elements associated with wound contracture and unfavorable scarring is a potentially important strategy in clinical wound management. In this study, the presence of α smooth muscle actin (αSMA), a protein involved in wound contraction, was analyzed in a series of wounds in which bovine fetal collagen (BFC) acellular dermal matrix (PriMatrix) was used in staged split thickness skin graft procedures. The results obtained through histological and quantitative image analyses of incidental biopsies from these wounds demonstrated a suppression of αSMA in the wound regions occupied by assimilated BFC relative to increased levels of αSMA found in other areas of the wound. The αSMA levels found in assimilated BFC were similar to αSMA levels in uninjured human dermis. These findings suggest a mechanism by which application of BFC could decrease contraction of full thickness skin wounds.

  4. 3D printed nanocomposite matrix for the study of breast cancer bone metastasis.

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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

  6. The Methoxyflavonoid Isosakuranetin Suppresses UV-B-Induced Matrix Metalloproteinase-1 Expression and Collagen Degradation Relevant for Skin Photoaging

    Science.gov (United States)

    Jung, Hana; Lee, Eunjoo H.; Lee, Tae Hoon; Cho, Man-Ho

    2016-01-01

    Solar ultraviolet (UV) radiation is a main extrinsic factor for skin aging. Chronic exposure of the skin to UV radiation causes the induction of matrix metalloproteinases (MMPs), such as MMP-1, and consequently results in alterations of the extracellular matrix (ECM) and skin photoaging. Flavonoids are considered as potent anti-photoaging agents due to their UV-absorbing and antioxidant properties and inhibitory activity against UV-mediated MMP induction. To identify anti-photoaging agents, in the present study we examined the preventative effect of methoxyflavonoids, such as sakuranetin, isosakuranetin, homoeriodictyol, genkwanin, chrysoeriol and syringetin, on UV-B-induced skin photo-damage. Of the examined methoxyflavonoids, pretreatment with isosakuranetin strongly suppressed the UV-B-mediated induction of MMP-1 in human keratinocytes in a concentration-dependent manner. Isosakuranetin inhibited UV-B-induced phosphorylation of mitogen-activated protein kinase (MAPK) signaling components, ERK1/2, JNK1/2 and p38 proteins. This result suggests that the ERK1/2 kinase pathways likely contribute to the inhibitory effects of isosakuranetin on UV-induced MMP-1 production in human keratinocytes. Isosakuranetin also prevented UV-B-induced degradation of type-1 collagen in human dermal fibroblast cells. Taken together, our findings suggest that isosakuranetin has the potential for development as a protective agent for skin photoaging through the inhibition of UV-induced MMP-1 production and collagen degradation. PMID:27598131

  7. The Methoxyflavonoid Isosakuranetin Suppresses UV-B-Induced Matrix Metalloproteinase-1 Expression and Collagen Degradation Relevant for Skin Photoaging.

    Science.gov (United States)

    Jung, Hana; Lee, Eunjoo H; Lee, Tae Hoon; Cho, Man-Ho

    2016-01-01

    Solar ultraviolet (UV) radiation is a main extrinsic factor for skin aging. Chronic exposure of the skin to UV radiation causes the induction of matrix metalloproteinases (MMPs), such as MMP-1, and consequently results in alterations of the extracellular matrix (ECM) and skin photoaging. Flavonoids are considered as potent anti-photoaging agents due to their UV-absorbing and antioxidant properties and inhibitory activity against UV-mediated MMP induction. To identify anti-photoaging agents, in the present study we examined the preventative effect of methoxyflavonoids, such as sakuranetin, isosakuranetin, homoeriodictyol, genkwanin, chrysoeriol and syringetin, on UV-B-induced skin photo-damage. Of the examined methoxyflavonoids, pretreatment with isosakuranetin strongly suppressed the UV-B-mediated induction of MMP-1 in human keratinocytes in a concentration-dependent manner. Isosakuranetin inhibited UV-B-induced phosphorylation of mitogen-activated protein kinase (MAPK) signaling components, ERK1/2, JNK1/2 and p38 proteins. This result suggests that the ERK1/2 kinase pathways likely contribute to the inhibitory effects of isosakuranetin on UV-induced MMP-1 production in human keratinocytes. Isosakuranetin also prevented UV-B-induced degradation of type-1 collagen in human dermal fibroblast cells. Taken together, our findings suggest that isosakuranetin has the potential for development as a protective agent for skin photoaging through the inhibition of UV-induced MMP-1 production and collagen degradation. PMID:27598131

  8. The Methoxyflavonoid Isosakuranetin Suppresses UV-B-Induced Matrix Metalloproteinase-1 Expression and Collagen Degradation Relevant for Skin Photoaging

    Directory of Open Access Journals (Sweden)

    Hana Jung

    2016-09-01

    Full Text Available Solar ultraviolet (UV radiation is a main extrinsic factor for skin aging. Chronic exposure of the skin to UV radiation causes the induction of matrix metalloproteinases (MMPs, such as MMP-1, and consequently results in alterations of the extracellular matrix (ECM and skin photoaging. Flavonoids are considered as potent anti-photoaging agents due to their UV-absorbing and antioxidant properties and inhibitory activity against UV-mediated MMP induction. To identify anti-photoaging agents, in the present study we examined the preventative effect of methoxyflavonoids, such as sakuranetin, isosakuranetin, homoeriodictyol, genkwanin, chrysoeriol and syringetin, on UV-B-induced skin photo-damage. Of the examined methoxyflavonoids, pretreatment with isosakuranetin strongly suppressed the UV-B-mediated induction of MMP-1 in human keratinocytes in a concentration-dependent manner. Isosakuranetin inhibited UV-B-induced phosphorylation of mitogen-activated protein kinase (MAPK signaling components, ERK1/2, JNK1/2 and p38 proteins. This result suggests that the ERK1/2 kinase pathways likely contribute to the inhibitory effects of isosakuranetin on UV-induced MMP-1 production in human keratinocytes. Isosakuranetin also prevented UV-B-induced degradation of type-1 collagen in human dermal fibroblast cells. Taken together, our findings suggest that isosakuranetin has the potential for development as a protective agent for skin photoaging through the inhibition of UV-induced MMP-1 production and collagen degradation.

  9. Three-dimensional poly (ε-caprolactone)/hydroxyapatite/collagen scaffolds incorporating bone marrow mesenchymal stem cells for the repair of bone defects.

    Science.gov (United States)

    Qi, Xin; Huang, Yinjun; Han, Dan; Zhang, Jieyuan; Cao, Jiaqing; Jin, Xiangyun; Huang, Jinghuan; Li, Xiaolin; Wang, Ting

    2016-04-01

    We previously demonstrated that three-dimensional (3D) hydroxyapatite (HAP)-collagen (COL)-coated poly(ε-caprolactone) (PCL) scaffolds (HAP-COL-PCL) possess appropriate nano-structures, surface roughness, and nutrients, providing a favorable environment for osteogenesis. However, the effect of using 3D HAP-COL-PCL scaffolds incorporating BMSCs for the repair of bone defects in rats has been not evaluated. 3D PCL scaffolds coated with HAP, collagen or HAP/COL and incorporating BMSCs were implanted into calvarial defects. At 12 weeks after surgery, the rats were sacrificed and crania were harvested to assess the bone defect repair using microcomputed tomography (micro-CT), histology, immunohistochemistry and sequential fluorescent labeling analysis. 3D micro-CT reconstructed images and quantitative analysis showed that HAP-COL-PCL groups possessed better bone-forming capacity than HAP-PCL groups or COL-PCL groups. Fluorescent labeling analysis revealed the percentage of tetracycline labeling, alizarin red labeling, and calcein labeling in HAP-COL-PCL groups were all greater than in the other two groups (P rats. PMID:26964015

  10. Mesenchymal stem cell responses to bone-mimetic electrospun matrices composed of polycaprolactone, collagen I and nanoparticulate hydroxyapatite.

    Directory of Open Access Journals (Sweden)

    Matthew C Phipps

    Full Text Available The performance of biomaterials designed for bone repair depends, in part, on the ability of the material to support the adhesion and survival of mesenchymal stem cells (MSCs. In this study, a nanofibrous bone-mimicking scaffold was electrospun from a mixture of polycaprolactone (PCL, collagen I, and hydroxyapatite (HA nanoparticles with a dry weight ratio of 50/30/20 respectively (PCL/col/HA. The cytocompatibility of this tri-component scaffold was compared with three other scaffold formulations: 100% PCL (PCL, 100% collagen I (col, and a bi-component scaffold containing 80% PCL/20% HA (PCL/HA. Scanning electron microscopy, fluorescent live cell imaging, and MTS assays showed that MSCs adhered to the PCL, PCL/HA and PCL/col/HA scaffolds, however more rapid cell spreading and significantly greater cell proliferation was observed for MSCs on the tri-component bone-mimetic scaffolds. In contrast, the col scaffolds did not support cell spreading or survival, possibly due to the low tensile modulus of this material. PCL/col/HA scaffolds adsorbed a substantially greater quantity of the adhesive proteins, fibronectin and vitronectin, than PCL or PCL/HA following in vitro exposure to serum, or placement into rat tibiae, which may have contributed to the favorable cell responses to the tri-component substrates. In addition, cells seeded onto PCL/col/HA scaffolds showed markedly increased levels of phosphorylated FAK, a marker of integrin activation and a signaling molecule known to be important for directing cell survival and osteoblastic differentiation. Collectively these results suggest that electrospun bone-mimetic matrices serve as promising degradable substrates for bone regenerative applications.

  11. Characterization of collagen fibers by means of texture analysis of second harmonic generation images using orientation-dependent gray level co-occurrence matrix method

    Science.gov (United States)

    Hu, Wenyan; Li, Hui; Wang, Chunyou; Gou, Shanmiao; Fu, Ling

    2012-02-01

    Collagen is the most prominent protein in the human body, making up 30% of the total protein content. Quantitative studies have shown structural differences between collagen fibers of the normal and diseased tissues, due to the remodeling of the extracellular matrix during the pathological process. The dominant orientation, which is an important characteristic of collagen fibers, has not been taken into consideration for quantitative collagen analysis. Based on the conventional gray level co-occurrence matrix (GLCM) method, the authors proposed the orientation-dependent GLCM (OD-GLCM) method by estimating the dominant orientation of collagen fibers. The authors validated the utility of the OD-GLCM method on second harmonic generation (SHG) microscopic images of tendons from rats with different ages. Compared with conventional GLCM method, the authors' method has not only improved the discrimination between different tissues but also provided additional texture information of the orderliness of collagen fibers and the fiber size. The OD-GLCM method was further applied to the differentiation of the preliminary SHG images of normal and cancerous human pancreatic tissues. The combination of SHG microscopy and the OD-GLCM method might be helpful for the evaluation of diseases marked with abnormal collagen morphology.

  12. Differentiation of Murine Bone Marrow-Derived Smooth Muscle Progenitor Cells Is Regulated by PDGF-BB and Collagen.

    Directory of Open Access Journals (Sweden)

    Clifford Lin

    Full Text Available Smooth muscle cells (SMCs are key regulators of vascular disease and circulating smooth muscle progenitor cells may play important roles in vascular repair or remodelling. We developed enhanced protocols to derive smooth muscle progenitors from murine bone marrow and tested whether factors that are increased in atherosclerotic plaques, namely platelet-derived growth factor-BB (PDGF-BB and monomeric collagen, can influence the smooth muscle specific differentiation, proliferation, and survival of mouse bone marrow-derived progenitor cells. During a 21 day period of culture, bone marrow cells underwent a marked increase in expression of the SMC markers α-SMA (1.93 ± 0.15 vs. 0.0008 ± 0.0003 (ng/ng GAPDH at 0 d, SM22-α (1.50 ± 0.27 vs. 0.005 ± 0.001 (ng/ng GAPDH at 0 d and SM-MHC (0.017 ± 0.004 vs. 0.001 ± 0.001 (ng/ng GAPDH at 0 d. Bromodeoxyuridine (BrdU incorporation experiments showed that in early culture, the smooth muscle progenitor subpopulation could be identified by high proliferative rates prior to the expression of smooth muscle specific markers. Culture of fresh bone marrow or smooth muscle progenitor cells with PDGF-BB suppressed the expression of α-SMA and SM22-α, in a rapidly reversible manner requiring PDGF receptor kinase activity. Progenitors cultured on polymerized collagen gels demonstrated expression of SMC markers, rates of proliferation and apoptosis similar to that of cells on tissue culture plastic; in contrast, cells grown on monomeric collagen gels displayed lower SMC marker expression, lower growth rates (319 ± 36 vs. 635 ± 97 cells/mm2, and increased apoptosis (5.3 ± 1.6% vs. 1.0 ± 0.5% (Annexin 5 staining. Our data shows that the differentiation and survival of smooth muscle progenitors are critically affected by PDGF-BB and as well as the substrate collagen structure.

  13. Biochemical Characterization of Major Bone-Matrix Proteins Using Nanoscale-Size Bone Samples and Proteomics Methodology*

    OpenAIRE

    Grażyna E Sroga; Karim, Lamya; Colón, Wilfredo; Vashishth, Deepak

    2011-01-01

    There is growing evidence supporting the need for a broad scale investigation of the proteins and protein modifications in the organic matrix of bone and the use of these measures to predict fragility fractures. However, limitations in sample availability and high heterogeneity of bone tissue cause unique experimental and/or diagnostic problems. We addressed these by an innovative combination of laser capture microscopy with our newly developed liquid chromatography separation methods, follow...

  14. Chemical modification of extracellular matrix by cold atmospheric plasma-generated reactive species affects chondrogenesis and bone formation.

    Science.gov (United States)

    Eisenhauer, Peter; Chernets, Natalie; Song, You; Dobrynin, Danil; Pleshko, Nancy; Steinbeck, Marla J; Freeman, Theresa A

    2016-09-01

    The goal of this study was to investigate whether cold plasma generated by dielectric barrier discharge (DBD) modifies extracellular matrices (ECM) to influence chondrogenesis and endochondral ossification. Replacement of cartilage by bone during endochondral ossification is essential in fetal skeletal development, bone growth and fracture healing. Regulation of this process by the ECM occurs through matrix remodelling, involving a variety of cell attachment molecules and growth factors, which influence cell morphology and protein expression. The commercially available ECM, Matrigel, was treated with microsecond or nanosecond pulsed (μsp or nsp, respectively) DBD frequencies conditions at the equivalent frequencies (1 kHz) or power (~1 W). Recombinant human bone morphogenetic protein-2 was added and the mixture subcutaneously injected into mice to simulate ectopic endochondral ossification. Two weeks later, the masses were extracted and analysed by microcomputed tomography. A significant increase in bone formation was observed in Matrigel treated with μsp DBD compared with control, while a significant decrease in bone formation was observed for both nsp treatments. Histological and immunohistochemical analysis showed Matrigel treated with μsp plasma increased the number of invading cells, the amount of vascular endothelial growth factor and chondrogenesis while the opposite was true for Matrigel treated with nsp plasma. In support of the in vivo Matrigel study, 10 T1/2 cells cultured in vitro on μsp DBD-treated type I collagen showed increased expression of adhesion proteins and activation of survival pathways, which decreased with nsp plasma treatments. These results indicate DBD modification of ECM can influence cellular behaviours to accelerate or inhibit chondrogenesis and endochondral ossification. Copyright © 2016 John Wiley & Sons, Ltd.

  15. Bisphosphonate treatment affects trabecular bone apparent modulus through micro-architecture rather than matrix properties

    DEFF Research Database (Denmark)

    Ding, Ming

    2004-01-01

    and trabecular architecture independently. Conventional histomorphometry and microdamage data were obtained from the second and third lumbar vertebrae of the same dogs [Bone 28 (2001) 524]. Bisphosphonate treatment resulted in an increased apparent Young's modulus, decreased bone turnover, increased calcified...... matrix density, and increased microdamage. We could not detect any change in the effective Young's modulus of the calcified matrix in the bisphosphonate treated groups. The observed increase in apparent Young's modulus was due to increased bone mass and altered trabecular architecture rather than changes...... in the calcified matrix modulus. We hypothesize that the expected increase in the Young's modulus of the calcified matrix due to the increased calcified matrix density was counteracted by the accumulation of microdamage. Udgivelsesdato: 2004 May...

  16. Expression of TGF-β in Region of Bone Defect Repaired by Collagen/Nano-beta-Tricalcium Phosphate Composite Artificial Bone

    Institute of Scientific and Technical Information of China (English)

    凌翔; 陈卫民; 刘胜洪; 王罡

    2003-01-01

    The distribution and function of transforming growth factor-beta (TGF-β) in the regionof bone defect repaired by collagen/nano-beta-tricalcium phosphate composite artificial bone (Co/N-TCP) and the ability of Co/N-TCP recruiting osteoblasts to precipitate the repair of bone defectwere investigated. Twenty-four domestic rabbits were operated on bilateral cranial bone to create anexperimental bone defect of 8.0 mm in diameter through the whole bone. On the left, Co/N-TCPwas implanted as experimental group, but on the right, Co/TCP was implanted as control group.At 2nd, 4th, 8th, 12th week after operation, all animals were sacrificed and the implanted materi-als with surrounding bone were taken out. Immunohistochemical staining was performed for TGF-βassay by avidin-biotin complex method (SABC). Simultaneously, TGF-β was quantitatively ana-lyzed by HPIAS-1000 imaging analysis system. The inmmunohistochemical staining for TGFβ re-vealed that osteoblasts and immature osteocytes highly expressed TGF-β. Diffused TGF-β positivestaining particles appeared in the mesenchymal and fibrous-tissue. There was no significant differ-ence in the TGF-β positive staining between two groups in the medial region to original osseous bedsat different time points (P>0. 05). However, in distal original osseous bed of the defected region,the positive expression of TGF-β in the Co/N-TCP group was significantly stronger than in the con-trol group (P<0.05 or 0.01). The Co/N-TCP has good bioactivities and ability of stimulating andconducting TGF-β to aggregate and precipitate the healing of bone defect.

  17. Gross anatomic and radiographic study of bone matrix gelatin implantation in tibial fracture of rabbit

    Directory of Open Access Journals (Sweden)

    Sobhani A

    2001-07-01

    Full Text Available Different ossificant materials have been used for induction of bone repair in many studies, and bone matrix gelatin which contains bone morphogenic proteins is one of the best ones. In present study we evaluated the role of this material in acceleration of bone repair in rabbit tibia. A hole of 3.5 mm diameter was made on right tibia of 10 and 12 rabbits as study and control group respectively. In the experiment group, in addition to Bone Wax, we applied bone matrix gelatin in the hole. Radiographic images were taken in days 0, 20, 40 and 53 after operation. In 6 rabbits of each group, photographic pictures were also taken after exposure of entire bone. In 6 controls less degree of restoration were seen on day 53. In 4 experimental animals restoration were completed by this time and in 2 speciments repair processing were better than controls. This results shows that bone matrix gelatin can be used as a accelerator of bone repair.

  18. Gross anatomic and radiographic study of bone matrix gelatin implantation in tibial fracture of rabbit1

    Directory of Open Access Journals (Sweden)

    Sobhani A

    2000-07-01

    Full Text Available Different ossificant materials have been used for induction of bone repair in many studies, and bone matrix gelatin which contains bone morphogenic proteins is one of the best ones. In present study we evaluated the role of this material in acceleration of bone repair in rabbit tibia. A hole of 3.5 mm diameter was made on right tibia of 10 and 12 rabbits as study and control group respectively. In the experiment group, in addition to Bone Wax, we applied bone matrix gelatin in the hole. Radiographic images were taken in days 0, 20, 40 and 53 after operation. In 6 rabbits of each group, photographic pictures were also taken after exposure of entire bone. In 6 controls less degree of restoration were seen on day 53. In 4 experimental animals restoration were completed by this time and in 2 speciments repair processing were better than controls. This results shows that bone matrix gelatin can be used as a accelerator of bone repair.

  19. Extracellular matrix production by nucleus pulposus and bone marrow stem cells in response to altered oxygen and glucose microenvironments.

    Science.gov (United States)

    Naqvi, Syeda M; Buckley, Conor T

    2015-12-01

    Bone marrow (BM) stem cells may be an ideal source of cells for intervertebral disc (IVD) regeneration. However, the harsh biochemical microenvironment of the IVD may significantly influence the biological and metabolic vitality of injected stem cells and impair their repair potential. This study investigated the viability and production of key matrix proteins by nucleus pulposus (NP) and BM stem cells cultured in the typical biochemical microenvironment of the IVD consisting of altered oxygen and glucose concentrations. Culture-expanded NP cells and BM stem cells were encapsulated in 1.5% alginate and ionically crosslinked to form cylindrical hydrogel constructs. Hydrogel constructs were maintained under different glucose concentrations (1, 5 and 25 mM) and external oxygen concentrations (5 and 20%). Cell viability was measured using the Live/Dead® assay and the production of sulphated glycosaminoglycans (sGAG), and collagen was quantified biochemically and histologically. For BM stem cells, IVD-like micro-environmental conditions (5 mM glucose and 5% oxygen) increased the accumulation of sGAG and collagen. In contrast, low glucose conditions (1 mM glucose) combined with 5% external oxygen concentration promoted cell death, inhibiting proliferation and the accumulation of sGAG and collagen. NP-encapsulated alginate constructs were relatively insensitive to oxygen concentration or glucose condition in that they accumulated similar amounts of sGAG under all conditions. Under IVD-like microenvironmental conditions, NP cells were found to have a lower glucose consumption rate compared with BM cells and may in fact be more suitable to adapt and sustain the harsh microenvironmental conditions. Considering the highly specialised microenvironment of the central NP, these results indicate that IVD-like concentrations of low glucose and low oxygen are critical and influential for the survival and biological behaviour of stem cells. Such findings may promote and accelerate

  20. Gray-Level Co-occurrence Matrix Bone Fracture Detection

    Directory of Open Access Journals (Sweden)

    Hum Y. Chai

    2011-01-01

    Full Text Available Problem statement: Currently doctors in orthopedic wards inspect the bone x-ray images according to their experience and knowledge in bone fracture analysis. Manual examination of x-rays has multitude drawbacks. The process is time-consuming and subjective. Approach: Since detection of fractures is an important orthopedics and radiologic problem and therefore a Computer Aided Detection(CAD system should be developed to improve the scenario. In this study, a fracture detection CAD based on GLCM recognition could improve the current manual inspection of x-ray images system. The GLCM for fracture and non-fracture bone is computed and analysis is made. Features of Homogeneity, contrast, energy, correlation are calculated to classify the fractured bone. Results: 30 images of femur fractures have been tested, the result shows that the CAD system can differentiate the x-ray bone into fractured and nonfractured femur. The accuracy obtained from the system is 86.67. Conclusion: The CAD system is proved to be effective in classifying the digital radiograph of bone fracture. However the accuracy rate is not perfect, the performance of this system can be further improved using multiple features of GLCM and future works can be done on classifying the bone into different degree of fracture specifically.

  1. Antioxidative Peptides Derived from Enzyme Hydrolysis of Bone Collagen after Microwave Assisted Acid Pre-Treatment and Nitrogen Protection

    Directory of Open Access Journals (Sweden)

    Jin Sun

    2010-11-01

    Full Text Available This study focused on the preparation method of antioxidant peptides by enzymatic hydrolysis of bone collagen after microwave assisted acid pre-treatment and nitrogen protection. Phosphoric acid showed the highest ability of hydrolysis among the four other acids tested (hydrochloric acid, sulfuric acid and/or citric acid. The highest degree of hydrolysis (DH was 9.5% using 4 mol/L phosphoric acid with a ratio of 1:6 under a microwave intensity of 510 W for 240 s. Neutral proteinase gave higher DH among the four protease tested (Acid protease, neutral protease, Alcalase and papain, with an optimum condition of: (1 ratio of enzyme and substrate, 4760 U/g; (2 concentration of substrate, 4%; (3 reaction temperature, 55 °C and (4 pH 7.0. At 4 h, DH increased significantly (P < 0.01 under nitrogen protection compared with normal microwave assisted acid pre-treatment hydrolysis conditions. The antioxidant ability of the hydrolysate increased and reached its maximum value at 3 h; however DH decreased dramatically after 3 h. Microwave assisted acid pre-treatment and nitrogen protection could be a quick preparatory method for hydrolyzing bone collagen.

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

    OpenAIRE

    Ye, Qing; Chen, Kaining; HUANG, WU; HE, YUNSONG; NONG, MINGSHAN; LI, CHUNXIANG; LIANG, TIANSEN

    2014-01-01

    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 sc...

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

    Science.gov (United States)

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

    2015-01-01

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

  4. Biomimetic fabrication of a three-level hierarchical calcium phosphate/collagen/hydroxyapatite scaffold for bone tissue engineering

    International Nuclear Information System (INIS)

    A three-level hierarchical calcium phosphate/collagen/hydroxyapatite (CaP/Col/HAp) scaffold for bone tissue engineering was developed using biomimetic synthesis. Porous CaP ceramics were first prepared as substrate materials to mimic the porous bone structure. A second-level Col network was then composited into porous CaP ceramics by vacuum infusion. Finally, a third-level HAp layer was achieved by biomimetic mineralization. The three-level hierarchical biomimetic scaffold was characterized using scanning electron microscopy, energy-dispersive x-ray spectra, x-ray diffraction and Fourier transform infrared spectroscopy, and the mechanical properties of the scaffold were evaluated using dynamic mechanical analysis. The results show that this scaffold exhibits a similar structure and composition to natural bone tissues. Furthermore, this three-level hierarchical biomimetic scaffold showed enhanced mechanical strength compared with pure porous CaP scaffolds. The biocompatibility and osteoinductivity of the biomimetic scaffolds were evaluated using in vitro and in vivo tests. Cell culture results indicated the good biocompatibility of this biomimetic scaffold. Faster and increased bone formation was observed in these scaffolds following a six-month implantation in the dorsal muscles of rabbits, indicating that this biomimetic scaffold exhibits better osteoinductivity than common CaP scaffolds. (papers)

  5. Editorial on the original article entitled "3D printing of composite calcium phosphate and collagen scaffolds for bone regeneration" published in the Biomaterials on February 14, 2014.

    Science.gov (United States)

    Li, Lan; Jiang, Qing

    2015-05-01

    The paper entitled "3D printing of composite calcium phosphate and collagen scaffolds for bone regeneration" published in the Biomaterials recently illuminated the way to make particular scaffolds with calcium phosphate (CaP) powder, phosphoric acid, type I collagen and Tween 80 in low temperature. After the optimal concentration of each component was determined, the scaffolds were evaluated in a critically sized murine femoral defect model and exhibited good material properties. We made some related introduction of materials applied in 3D printing for bone tissue engineering based on this article to demonstrate the current progress in this field of study.

  6. Measurement of matrix metalloproteinase 9-mediated Collagen type III degradation fragment as a marker of skin fibrosis

    Directory of Open Access Journals (Sweden)

    Larsen Lise

    2011-03-01

    Full Text Available Abstract Background The current study utilized a Bleomycin-induced model of skin fibrosis to investigate the neo-epitope CO3-610 (KNGETGPQGP, a fragment of collagen III released during matrix metalloproteinase-9 (MMP9 degradation of the protein, we have previously described as a novel biomarker for liver fibrosis. The aim was to investigate CO3-610 levels in another well characterised model of fibrosis, to better describe the biomarker in relation to additional fibrotic pathologies. Methods Skin fibrosis was induced by daily injections of Bleomycin to a total of 52 female C3 H mice, while control mice (n = 28 were treated with phosphate buffered saline (PBS, for 2, 4, 6 or 8 weeks. Skin fibrosis was evaluated using Visiopharm software on Sirius-red stained skin sections. Urine ELISA assays and creatinine corrections were performed to measure CO3-610 levels. Results CO3-610 levels were significantly higher in Bleomycin-treated vs. PBS-treated mice at each time point of termination. The mean increases were: 59.2%, P Conclusion Increased levels in mouse urine of the MMP-9 mediated collagen III degradation fragment CO3-610 were correlated with skin fibrosis progression, suggesting that CO3-610 may be a potential positive biomarker to study the pathogenesis of skin fibrosis in mice.

  7. Vibrational spectroscopy in biomedical science: bone

    Science.gov (United States)

    Gamsjäger, Sonja; Zoehrer, R.; Roschger, P.; Fratzl, P.; Klaushofer, K.; Mendelsohn, R.; Paschalis, E. P.

    2009-02-01

    Fourier transform infrared imaging (FTIR) and Raman Microspectroscopy are powerful tools for characterizing the distribution of different chemical moieties in heterogeneous materials. FTIR and Raman measurements have been adapted to assess the maturity of the mineral and the quality of the organic component (collagen and non-collagenous proteins) of the mineralized tissue in bone. Unique to the FTIRI analysis is the capability to provide the spatial distribution of two of the major collagen cross-links (pyridinoline, and dehydro-dihydroxylysinonorleucine) and through the study of normal and diseased bone, relate them to bone strength. These FTIR parameters have been validated based on analysis of model compounds. It is widely accepted that bone strength is determined by bone mass and bone quality. The latter is a multifactorial term encompassing the material and structural properties of bone, and one important aspect of the bone material properties is the organic matrix. The bone material properties can be defined by parameters of mineral and collagen, as determined by FTIR and Raman analysis. Considerably less attention has been directed at collagen, although there are several publications in the literature reporting altered collagen properties associated with fragile bone, in both animals and humans. Since bone is a heterogeneous tissue due to the remodeling process, microscopic areas may be carefully selected based on quantitative Backscattered Electron Imaging or histological staining, thus ensuring comparison of areas with similar metabolic activity and mineral content. In conclusion, FTIRI and Raman vibrational spectroscopy are proving to be powerful tools in bone-related medical research.

  8. Extracellular matrix of adipogenically differentiated mesenchymal stem cells reveals a network of collagen filaments, mostly interwoven by hexagonal structural units.

    Science.gov (United States)

    Ullah, Mujib; Sittinger, Michael; Ringe, Jochen

    2013-01-01

    Extracellular matrix (ECM) is the non-cellular component of tissues, which not only provides biological shelter but also takes part in the cellular decisions for diverse functions. Every tissue has an ECM with unique composition and topology that governs the process of determination, differentiation, proliferation, migration and regeneration of cells. Little is known about the structural organization of matrix especially of MSC-derived adipogenic ECM. Here, we particularly focus on the composition and architecture of the fat ECM to understand the cellular behavior on functional bases. Thus, mesenchymal stem cells (MSC) were adipogenically differentiated, then, were transferred to adipogenic propagation medium, whereas they started the release of lipid droplets leaving bare network of ECM. Microarray analysis was performed, to indentify the molecular machinery of matrix. Adipogenesis was verified by Oil Red O staining of lipid droplets and by qPCR of adipogenic marker genes PPARG and FABP4. Antibody staining demonstrated the presence of collagen type I, II and IV filaments, while alkaline phosphatase activity verified the ossified nature of these filaments. In the adipogenic matrix, the hexagonal structures were abundant followed by octagonal structures, whereas they interwoven in a crisscross manner. Regarding molecular machinery of adipogenic ECM, the bioinformatics analysis revealed the upregulated expression of COL4A1, ITGA7, ITGA7, SDC2, ICAM3, ADAMTS9, TIMP4, GPC1, GPC4 and downregulated expression of COL14A1, ADAMTS5, TIMP2, TIMP3, BGN, LAMA3, ITGA2, ITGA4, ITGB1, ITGB8, CLDN11. Moreover, genes associated with integrins, glycoproteins, laminins, fibronectins, cadherins, selectins and linked signaling pathways were found. Knowledge of the interactive-language between cells and matrix could be beneficial for the artificial designing of biomaterials and bioscaffolds. PMID:23851162

  9. Hybrid Membranes of PLLA/Collagen for Bone Tissue Engineering: A Comparative Study of Scaffold Production Techniques for Optimal Mechanical Properties and Osteoinduction Ability

    Directory of Open Access Journals (Sweden)

    Flávia Gonçalves

    2015-01-01

    Full Text Available Synthetic and natural polymer association is a promising tool in tissue engineering. The aim of this study was to compare five methodologies for producing hybrid scaffolds for cell culture using poly-l-lactide (PLLA and collagen: functionalization of PLLA electrospun by (1 dialkylamine and collagen immobilization with glutaraldehyde and by (2 hydrolysis and collagen immobilization with carbodiimide chemistry; (3 co-electrospinning of PLLA/chloroform and collagen/hexafluoropropanol (HFP solutions; (4 co-electrospinning of PLLA/chloroform and collagen/acetic acid solutions and (5 electrospinning of a co-solution of PLLA and collagen using HFP. These materials were evaluated based on their morphology, mechanical properties, ability to induce cell proliferation and alkaline phosphatase activity upon submission of mesenchymal stem cells to basal or osteoblastic differentiation medium (ODM. Methods (1 and (2 resulted in a decrease in mechanical properties, whereas methods (3, (4 and (5 resulted in materials of higher tensile strength and osteogenic differentiation. Materials yielded by methods (2, (3 and (5 promoted osteoinduction even in the absence of ODM. The results indicate that the scaffold based on the PLLA/collagen blend exhibited optimal mechanical properties and the highest capacity for osteodifferentiation and was the best choice for collagen incorporation into PLLA in bone repair applications.

  10. Matrix-Bound VEGF Mimetic Peptides: Design and Endothelial Cell Activation in Collagen Scaffolds

    OpenAIRE

    Chan, Tania R.; Stahl, Patrick J.; Yu, S. Michael

    2011-01-01

    Long term survival and success of artificial tissue constructs depend greatly on vascularization. Endothelial cell (EC) differentiation and vasculature formation are dependent on spatio-temporal cues in the extracellular matrix that dynamically interact with cells, a process difficult to reproduce in artificial systems. Here we present a novel bifunctional peptide that mimics matrix-bound vascular endothelial growth factor (VEGF) and can be used to encode spatially controlled angiogenic signa...

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

    Science.gov (United States)

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

    2016-01-01

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

  12. The Three-Dimensional Collagen Scaffold Improves the Stemness of Rat Bone Marrow Mesenchymal Stem Cells

    Institute of Scientific and Technical Information of China (English)

    Sufang Han; Yannan Zhao; Zhifeng Xiao; Jin Han; Bing Chen; Lei Chen; Jianwu Dai

    2012-01-01

    Mesenchymal stem cells (MSCs) show the great promise for the treatment of a variety of diseases because of their self-renewal and multipotential abilities.MSCs are generally cultured on two-dimensional (2D) substrate in vitro.There are indications that they may simultaneously lose their stemness and multipotentiality as the result of prolonged 2D culture.In this study,we used three-dimensional (3D) collagen scaffolds as rat MSCs carrier and compared the properties of MSCs on 3D collagen scaffolds with monolayer cultured MSCs.The results demonstrated that collagen scaffolds were suitable for rat MSCs adherence and proliferation.More importantly,compared to MSCs under 2D culture,3D MSCs significantly maintained higher expression levels of stemness genes (Oct4,Sox2,Rex-1 and Nanog),yielded high frequencies of colony-forming units-fibroblastic (CFU-F) and showed enhanced osteogenic and adipogenic differentiation efficiency upon induction.Thus,3D collagen scaffolds may be beneficial for expanding rat MSCs while maintaining the stem cell properties in vitro.

  13. Collagens VI and XII form complexes mediating osteoblast interactions during osteogenesis.

    Science.gov (United States)

    Izu, Yayoi; Ezura, Yoichi; Koch, Manuel; Birk, David E; Noda, Masaki

    2016-06-01

    Bone formation is precisely regulated by cell-cell communication in osteoblasts. We have previously demonstrated that genetic deletion of Col6a1 or Col12a1 impairs osteoblast connections and/or communication in mice, resulting in bone mass reduction and bone fragility. Mutations of the genes encoding collagen VI cause Ullrich congenital muscular dystrophy (UCMD) and Bethlem myopathy (BM), which have overlapping phenotypes involving connective tissue and muscle. Recent studies have identified COL12A1 gene mutations in patients with UCMD- and BM-like disorders harboring no COL6 mutations, indicating the shared functions of these collagens in connective tissue homeostasis. The purpose of this investigation has been to test the hypothesis that collagens VI and XII have coordinate regulatory role(s) during bone formation. We analyzed the localization of collagens VI and XII relative to primary osteoblasts during osteogenesis. Immunofluorescence analysis demonstrated that collagens VI and XII colocalized in matrix bridges between adjacent cells during periods when osteoblasts were establishing cell-cell connections. Quantification of cells harboring collagen bridges demonstrated that matrix bridges were composed of collagens VI and XII but not collagen I. Interestingly, matrix bridge formation was impaired in osteoblasts deficient in either Col6a1 or Col12a1, suggesting that both collagens were indispensable for matrix bridge formation. These data demonstrate, for the first time, a functional relationship between collagens VI and XII during osteogenesis and indicate that a complex containing collagens VI and XII is essential for the formation of a communicating cellular network during bone formation. PMID:26753503

  14. First-line treatment with bortezomib rapidly stimulates both osteoblast activity and bone matrix deposition in patients with multiple myeloma, and stimulates osteoblast proliferation and differentiation in vitro

    DEFF Research Database (Denmark)

    Lund, Thomas; Søe, Kent; Abildgaard, Niels;

    2010-01-01

    studied in vitro. RESULTS: Treatment with bortezomib caused a significant increase in bone-specific alkaline phosphatase and pro-collagen type I N-terminal propeptide, a novel bone formation marker. The addition of a glucocorticoid resulted in a transient decrease in collagen deposition. In vitro...

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

    Science.gov (United States)

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

    2015-11-01

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

  16. Micro/Nano Multilayered Scaffolds of PLGA and Collagen by Alternately Electrospinning for Bone Tissue Engineering.

    Science.gov (United States)

    Kwak, Sanghwa; Haider, Adnan; Gupta, Kailash Chandra; Kim, Sukyoung; Kang, Inn-Kyu

    2016-12-01

    The dual extrusion electrospinning technique was used to fabricate multilayered 3D scaffolds by stacking microfibrous meshes of poly(lactic acid-co-glycolic acid) (PLGA) in alternate fashion to micro/nano mixed fibrous meshes of PLGA and collagen. To fabricate the multilayered scaffold, 35 wt% solution of PLGA in THF-DMF binary solvent (3:1) and 5 wt% solution of collagen in hexafluoroisopropanol (HFIP) with and without hydroxyapatite nanorods (nHA) were used. The dual and individual electrospinning of PLGA and collagen were carried out at flow rates of 1.0 and 0.5 mL/h, respectively, at an applied voltage of 20 kV. The density of collagen fibers in multilayered scaffolds has controlled the adhesion, proliferation, and osteogenic differentiation of MC3T3-E1 cells. The homogeneous dispersion of glutamic acid-modified hydroxyapatite nanorods (nHA-GA) in collagen solution has improved the osteogenic properties of fabricated multilayered scaffolds. The fabricated multilayered scaffolds were characterized using FT-IR, X-ray photoelectron spectroscopy, and transmission electron microscopy (TEM). The scanning electron microscopy (FE-SEM) was used to evaluate the adhesion and spreads of MC3T3-E1 cells on multilayered scaffolds. The activity of MC3T3-E1 cells on the multilayered scaffolds was evaluated by applying MTT, alkaline phosphatase, Alizarin Red, von Kossa, and cytoskeleton F-actin assaying protocols. The micro/nano fibrous PLGA-Col-HA scaffolds were found to be highly bioactive in comparison to pristine microfibrous PLGA and micro/nano mixed fibrous PLGA and Col scaffolds. PMID:27376895

  17. Micro/Nano Multilayered Scaffolds of PLGA and Collagen by Alternately Electrospinning for Bone Tissue Engineering

    Science.gov (United States)

    Kwak, Sanghwa; Haider, Adnan; Gupta, Kailash Chandra; Kim, Sukyoung; Kang, Inn-Kyu

    2016-07-01

    The dual extrusion electrospinning technique was used to fabricate multilayered 3D scaffolds by stacking microfibrous meshes of poly(lactic acid-co-glycolic acid) (PLGA) in alternate fashion to micro/nano mixed fibrous meshes of PLGA and collagen. To fabricate the multilayered scaffold, 35 wt% solution of PLGA in THF-DMF binary solvent (3:1) and 5 wt% solution of collagen in hexafluoroisopropanol (HFIP) with and without hydroxyapatite nanorods (nHA) were used. The dual and individual electrospinning of PLGA and collagen were carried out at flow rates of 1.0 and 0.5 mL/h, respectively, at an applied voltage of 20 kV. The density of collagen fibers in multilayered scaffolds has controlled the adhesion, proliferation, and osteogenic differentiation of MC3T3-E1 cells. The homogeneous dispersion of glutamic acid-modified hydroxyapatite nanorods (nHA-GA) in collagen solution has improved the osteogenic properties of fabricated multilayered scaffolds. The fabricated multilayered scaffolds were characterized using FT-IR, X-ray photoelectron spectroscopy, and transmission electron microscopy (TEM). The scanning electron microscopy (FE-SEM) was used to evaluate the adhesion and spreads of MC3T3-E1 cells on multilayered scaffolds. The activity of MC3T3-E1 cells on the multilayered scaffolds was evaluated by applying MTT, alkaline phosphatase, Alizarin Red, von Kossa, and cytoskeleton F-actin assaying protocols. The micro/nano fibrous PLGA-Col-HA scaffolds were found to be highly bioactive in comparison to pristine microfibrous PLGA and micro/nano mixed fibrous PLGA and Col scaffolds.

  18. Bone-Forming Capabilities of a Newly Developed NanoHA Composite Alloplast Infused with Collagen: A Pilot Study in the Sheep Mandible

    Directory of Open Access Journals (Sweden)

    Charles Marin

    2013-01-01

    Full Text Available Lateral or vertical bone augmentation has always been a challenge, since the site is exposed to constant pressure from the soft tissue, and blood supply only exists from the donor site. Although, for such clinical cases, onlay grafting with autogenous bone is commonly selected, the invasiveness of the secondary surgical site and the relatively fast resorption rate have been reported as a drawback, which motivated the investigation of alternative approaches. This study evaluated the bone-forming capability of a novel nanoHA alloplast infused with collagen graft material made from biodegradable polylactic acid/polyglycolic acid versus a control graft material with the same synthesized alloplast without the nanoHA component and collagen infiltration. The status of newly formed bone and the resorption of the graft material were evaluated at 6 weeks in vivo histologically and three dimensionally by means of 3D microcomputed tomography. The histologic observation showed that newly formed bone ingrowth and internal resorption of the block were observed for the experimental blocks, whereas for the control blocks less bone ingrowth occurred along with lower resorption rate of the block material. The three-dimensional observation indicated that the experimental block maintained the external geometry, but at the same time successfully altered the graft material into bone. It is suggested that the combination of numerous factors contributed to the bone ingrowth and the novel development could be an alternative bone grafting choice.

  19. Cultivation of Keratinocytes and Fibroblasts in a Three-Dimensional Bovine Collagen-Elastin Matrix (Matriderm® and Application for Full Thickness Wound Coverage in Vivo

    Directory of Open Access Journals (Sweden)

    Jasper Killat

    2013-07-01

    Full Text Available New skin substitutes for burn medicine or reconstructive surgery pose an important issue in plastic surgery. Matriderm® is a clinically approved three-dimensional bovine collagen-elastin matrix which is already used as a dermal substitute of full thickness burn wounds. The drawback of an avital matrix is the limited integration in full thickness skin defects, depending on the defect size. To further optimize this process, Matriderm® has also been studied as a matrix for tissue engineering of skin albeit long-term cultivation of the matrix with cells has been difficult. Cells have generally been seeded onto the matrix with high cell loss and minimal time-consuming migration. Here we developed a cell seeded skin equivalent after microtransfer of cells directly into the matrix. First, cells were cultured, and microinjected into Matriderm®. Then, cell viability in the matrix was determined by histology in vitro. As a next step, the skin substitute was applied in vivo into a full thickness rodent wound model. The wound coverage and healing was observed over a period of two weeks followed by histological examination assessing cell viability, proliferation and integration into the host. Viable and proliferating cells could be found throughout the entire matrix. The presented skin substitute resembles healthy skin in morphology and integrity. Based on this study, future investigations are planned to examine behaviour of epidermal stem cells injected into a collagen-elastin matrix under the aspects of establishment of stem cell niches and differentiation.

  20. Biological Evaluation (In Vitro and In Vivo) of Bilayered Collagenous Coated (Nano Electrospun and Solid Wall) Chitosan Membrane for Periodontal Guided Bone Regeneration.

    Science.gov (United States)

    Lotfi, Ghogha; Shokrgozar, Mohammad Ali; Mofid, Rasoul; Abbas, Fatemeh Mashhadi; Ghanavati, Farzin; Baghban, Alireza Akbarzadeh; Yavari, Seyedeh Kimia; Pajoumshariati, Seyedramin

    2016-07-01

    The application of barrier membranes in guided bone regeneration (GBR) has become a commonly used surgical technique in periodontal research. The objectives of this study were to evaluate the in vitro biocompatibility and osteogenic differentiation of mesenchymal stem cells (MSCs) on two different collagenous coatings (nano electrospun fibrous vs. solid wall) of bilayered collagen/chitosan membrane and their histological evaluation on bone regeneration in rabbit calvarial defects. It was found that chitosan-nano electrospun collagen (CNC) membranes had higher proliferation/metabolic activity compared to the chitosan-collagen (CC) and pristine chitosan membranes. The qRT-PCR analysis demonstrated the CNC membranes induced significant expression of osteogenic genes (Osteocalcin, RUNX2 and Col-α1) in MSCs. Moreover, higher calcium content and alkaline phosphatase activity of MSCs were observed compared to the other groups. Histologic and histomorphometric evaluations were performed on the uncovered (negative control) as well as covered calvarial defects of ten adult white rabbits with different membranes (CNC, CC, BioGide (BG, positive control)) at 1 and 2 months after surgery. More bone formation was detected in the defects covered with CNC and BG membranes than those covered by CC and the negative control. No inflammation and residual biomaterial particles were observed on the membrane surface or in the surrounding tissues in the surgical areas. These results suggest that bilayer CNC membrane can have the potential for use as a GBR membrane material facilitating bone formation. PMID:26586588

  1. Effects of fatigue on microstructure and mechanical properties of bone organic matrix under compression

    International Nuclear Information System (INIS)

    The aim of the study was to investigate whether a fatigue induced weakening of cortical bone was revealed in microstructure and mechanical competence of demineralized bone matrix. Two types of cortical bone samples (plexiform and Haversian) were use. Bone slabs from the midshaft of bovine femora were subjected to cyclical bending. Fatigued and adjacent control samples were cut into cubes and demineralized in ethylenediaminetetraacetic acid. Demineralized samples were either subjected to microscopic quantitative image analysis, or compressed to failure (in longitudinal or transverse direction) with a simultaneous analysis of acoustic emission (AE). In fatigued samples porosity of organic matrix and average area of pores have risen, along with a change in the pores shape. The effect of fatigue depended on the type of the bone, being more pronounced in the plexiform than in Haversian tissue. Demineralized bone matrix was anisotropic under compressive loads in both types of cortical structure. The main result of fatigue pretreatment on mechanical parameters was a significant decrease of ultimate strain in the transverse direction in plexiform samples. The decrease of strain in this group was accompanied by a considerable increase of the fraction of large pores and a significant change in AE energy.

  2. Ca2+ channel blockers modulate metabolism of collagens within the extracellular matrix.

    OpenAIRE

    Roth, M; Eickelberg, O.; Kohler, E.; Erne, P; Block, L H

    1996-01-01

    The extracellular matrix (ECM) is an intricate network composed of an array of macromolecules capable of regulating the functional responsiveness of cells. Its composition greatly varies among different types of tissue, and dysregulation of its metabolism may contribute to vascular remodeling during the pathogenesis of various diseases, including atherosclerosis. In view of their antiatherosclerotic effects, the role of Ca2+ channel blockers in the metabolism of ECM was examined. Nanomolar co...

  3. Mechanical properties, biological activity and protein controlled release by poly(vinyl alcohol)–bioglass/chitosan–collagen composite scaffolds: A bone tissue engineering applications

    Energy Technology Data Exchange (ETDEWEB)

    Pon-On, Weeraphat, E-mail: fsciwpp@ku.ac.th [Department of Physics, Faculty of Science, Kasetsart University, Bangkok 10900 (Thailand); Charoenphandhu, Narattaphol; Teerapornpuntakit, Jarinthorn; Thongbunchoo, Jirawan; Krishnamra, Nateetip [Center of Calcium and Bone Research (COCAB), Faculty of Science, Mahidol University (Thailand); Department of Physiology, Faculty of Science, Mahidol University (Thailand); Tang, I-Ming [ThEP Center, Commission of Higher Education, 328 Si Ayutthaya Rd. (Thailand); Department of Materials Science, Faculty of Science, Kasetsart University, Bangkok 10900 (Thailand)

    2014-05-01

    In the present study, composite scaffolds made with different weight ratios (0.5:1, 1:1 and 2:1) of bioactive glass (15Ca:80Si:5P) (BG)/polyvinyl alcohol (PVA) (PVABG) and chitosan (Chi)/collagen (Col) (ChiCol) were prepared by three mechanical freeze–thaw followed by freeze-drying to obtain the porous scaffolds. The mechanical properties and the in vitro biocompatibility of the composite scaffolds to simulated body fluid (SBF) and to rat osteoblast-like UMR-106 cells were investigated. The results from the studies indicated that the porosity and compressive strength were controlled by the weight ratio of PVABG:ChiCol. The highest compressive modulus of the composites made was 214.64 MPa which was for the 1:1 weight ratio PVABG:ChiCol. Mineralization study in SBF showed the formation of apatite crystals on the PVABG:ChiCol surface after 7 days of incubation. In vitro cell availability and proliferation tests confirmed the osteoblast attachment and growth on the PVABG:ChiCol surface. MTT and ALP tests on the 1:1 weight ratio PVABG:ChiCol composite indicated that the UMR-106 cells were viable. Alkaline phosphatase activity was found to increase with increasing culturing time. In addition, we showed the potential of PVABG:ChiCol drug delivery through PBS solution studies. 81.14% of BSA loading had been achieved and controlled release for over four weeks was observed. Our results indicated that the PVABG:ChiCol composites, especially the 1:1 weight ratio composite exhibited significantly improved mechanical, mineral deposition, biological properties and controlled release. This made them potential candidates for bone tissue engineering applications. - Graphical abstract: Mechanical properties, biological activity and protein controlled release by poly(vinyl alcohol)–bioglass/chitosan–collagen composite scaffolds: A bone tissue engineering applications. - Highlights: • Preparation of PVABG:ChiCol hybrid composites and their bioactivities • Mechanical

  4. Mechanical properties, biological activity and protein controlled release by poly(vinyl alcohol)–bioglass/chitosan–collagen composite scaffolds: A bone tissue engineering applications

    International Nuclear Information System (INIS)

    In the present study, composite scaffolds made with different weight ratios (0.5:1, 1:1 and 2:1) of bioactive glass (15Ca:80Si:5P) (BG)/polyvinyl alcohol (PVA) (PVABG) and chitosan (Chi)/collagen (Col) (ChiCol) were prepared by three mechanical freeze–thaw followed by freeze-drying to obtain the porous scaffolds. The mechanical properties and the in vitro biocompatibility of the composite scaffolds to simulated body fluid (SBF) and to rat osteoblast-like UMR-106 cells were investigated. The results from the studies indicated that the porosity and compressive strength were controlled by the weight ratio of PVABG:ChiCol. The highest compressive modulus of the composites made was 214.64 MPa which was for the 1:1 weight ratio PVABG:ChiCol. Mineralization study in SBF showed the formation of apatite crystals on the PVABG:ChiCol surface after 7 days of incubation. In vitro cell availability and proliferation tests confirmed the osteoblast attachment and growth on the PVABG:ChiCol surface. MTT and ALP tests on the 1:1 weight ratio PVABG:ChiCol composite indicated that the UMR-106 cells were viable. Alkaline phosphatase activity was found to increase with increasing culturing time. In addition, we showed the potential of PVABG:ChiCol drug delivery through PBS solution studies. 81.14% of BSA loading had been achieved and controlled release for over four weeks was observed. Our results indicated that the PVABG:ChiCol composites, especially the 1:1 weight ratio composite exhibited significantly improved mechanical, mineral deposition, biological properties and controlled release. This made them potential candidates for bone tissue engineering applications. - Graphical abstract: Mechanical properties, biological activity and protein controlled release by poly(vinyl alcohol)–bioglass/chitosan–collagen composite scaffolds: A bone tissue engineering applications. - Highlights: • Preparation of PVABG:ChiCol hybrid composites and their bioactivities • Mechanical

  5. Pitfalls in comparing modern hair and fossil bone collagen C and N isotopic data to reconstruct ancient diets: a case study with cave bears (Ursus spelaeus).

    Science.gov (United States)

    Bocherens, Hervé; Grandal-d'Anglade, Aurora; Hobson, Keith A

    2014-01-01

    Stable isotope analyses provide one of the few means to evaluate diet of extinct taxa. However, interpreting isotope data from bone collagen of extinct animals based on isotopic patterns in different tissues of modern animal proxies is precarious. For example, three corrections are needed before making comparisons of recent hair and ancient bone collagen: calibration of carbon-13 variations in atmospheric CO2, different isotopic discrimination between diet-hair keratin and diet-bone collagen, and time averaging of bone collagen versus short-term record in hair keratin. Recently, Robu et al. [Isotopic evidence for dietary flexibility among European Late Pleistocene cave bears (Ursus spelaeus). Can J Zool. 2013;91:227-234] published an article comparing extant carbon (δ(13)C) and nitrogen (δ(15)N) stable isotopic data of European cave bear bone collagen with those of Yellowstone Park grizzly bear hair in order to test the prevailing assumption of a largely vegetarian diet among cave bears. The authors concluded that cave bears were carnivores. This work is unfortunately unfounded as the authors failed to consider the necessary corrections listed above. When these corrections are applied to the Romanian cave bears, these individuals can be then interpreted without involving consumption of high trophic-level food, and environmental changes are probably the reason for the unusual isotopic composition of these cave bears in comparison with other European cave bears, rather than a change of diet. We caution researchers to pay careful attention to these factors when interpreting feeding ecology of extinct fauna using stable isotope techniques.

  6. Short bouts of mechanical loading are as effective as dexamethasone at inducing matrix production by human bone marrow Mesenchymal stem cell

    Directory of Open Access Journals (Sweden)

    A Sittichokechaiwut

    2010-07-01

    Full Text Available Dexamethasone (Dex is used widely to induce differentiation in human mesenchymal stem cells (hMSCs; however, using a pharmaceutical agent to stimulate hMSC differentiation is not the best choice for engineered tissue transplantation due to potential side-effects. The goal of the present study was to investigate the effects of dynamic compressive loading on differentiation and mineralized matrix production of hMSCs in 3D polyurethane scaffolds, using a loading regimen previously shown to stimulate mineralised matrix production of mature bone cells (MLO-A5. hMSCs were seeded in polyurethane scaffolds and cultured in standard culture media with or without Dex. Cell-seeded scaffolds were compressed at 5% global strain for 2 h on day 9 and then every 5 days in a media-filled sterile chamber. Samples were tested for mRNA expression of alkaline phosphatase (ALP, osteopontin (OPN, collagen type 1 (col 1 and runt-related transcription factor-2 (RUNX-212 h after the first loading, cell viability by MTS assay and alkaline phosphatase activity at day 12 of culture and cell viability, collagen content by Sirius red and calcium content by alizarin red at day 24 of culture. Neither Dex nor loading had significant effects on cell viability. Collagen content was significantly higher (p<0.01 in the loaded group compared with the non-loaded group in all conditions. There was no difference in ALP activity or the amount of collagen and calcium produced between the non-loaded group supplemented with Dex and the loaded group without Dex. We conclude that dynamic loading has the ability to stimulate osteogenic differentiation of hMSC in the absence of glucocorticoids.

  7. Biomimetically Ornamented Rapid Prototyping Fabrication of an Apatite-Collagen-Polycaprolactone Composite Construct with Nano-Micro-Macro Hierarchical Structure for Large Bone Defect Treatment.

    Science.gov (United States)

    Wang, Jinbing; Wu, Dingyu; Zhang, Zhanzhao; Li, Jun; Shen, Yi; Wang, Zhenxing; Li, Yu; Zhang, Zhi-Yong; Sun, Jian

    2015-12-01

    Biomaterial-based bone graft substitute with favorable mechanical and biological properties could be used as an alternative to autograft for large defect treatment. Here, an apatite-collagen-polycaprolactone (Ap-Col-PCL) composite construct was developed with unique nano-micro-macro hierarchical architectures by combining rapid prototyping (RP) fabrication technology and a 3D functionalization strategy. Macroporous PCL framework was fabricated using RP technology, then functionalized by collagen incorporation and biomimetic deposition. Ap-Col-PCL composite construct was characterized with hierarchical architectures of a nanoscale (∼100 nm thickness and ∼1 μm length) platelike apatite coating on the microporous (126 ± 18 μm) collagen networks, which homogeneously filled the macroporous (∼1000 μm) PCL frameworks and possessed a favorable hydrophilic property and compressive modulus (68.75 ± 3.39 MPa) similar to that of cancellous bone. Moreover, in vitro cell culture assay and in vivo critical-sized bone defect implantation demonstrated that the Ap-Col-PCL construct could not only significantly increase the cell adhesion capability (2.0-fold) and promote faster cell proliferation but also successfully bridge the segmental long bone defect within 12 weeks with much more bone regeneration (5.2-fold), better osteointegration (7.2-fold), and a faster new bone deposition rate (2.9-fold). Our study demonstrated that biomimetically ornamented Ap-Col-PCL constructs exhibit a favorable mechanical property, more bone tissue ingrowth, and better osteointegration capability as an effective bone graft substitute for critical-sized bone defect treatment; meanwhile, it can also harness the advantages of RP technology, in particular, facilitating the customization of the shape and size of implants according to medical images during clinical application.

  8. Utility of tricalcium phosphate and osteogenic matrix cellsheet constructs for bone defect reconstruction

    Institute of Scientific and Technical Information of China (English)

    2015-01-01

    AIM To determine the effects of transplanting osteogenicmatrix cell sheets and beta-tricalcium phosphate(TCP) constructs on bone formation in bone defects.METHODS: Osteogenic matrix cell sheets were preparedfrom bone marrow stromal cells (BMSCs), anda porous TCP ceramic was used as a scaffold. Threeexperimental groups were prepared, comprised of TCPscaffolds (1) seeded with BMSCs; (2) wrapped withosteogenic matrix cell sheets; or (3) both. Constructswere implanted into a femoral defect model in rats andbone growth was evaluated by radiography, histology,biochemistry, and mechanical testing after 8 wk.RESULTS: In bone defects, constructs implanted withcell sheets showed callus formation with segmental or continuous bone formation at 8 wk, in contrast toTCP seeded with BMSCs, which resulted in bone nonunion.Wrapping TCP constructs with osteogenic matrixcell sheets increased their osteogenic potential andresulting bone formation, compared with conventionalbone tissue engineering TCP scaffolds seeded withBMSCs. The compressive stiffness (mean ± SD) valueswere 225.0 ± 95.7, 30.0 ± 11.5, and 26.3 ± 10.6MPa for BMSC/TCP/Sheet constructs with continuousbone formation, BMSC/TCP/Sheet constructs withsegmental bone formation, and BMSC/TCP constructs,respectively. The compressive stiffness of BMSC/TCP/Sheet constructs with continuous bone formation wassignificantly higher than those with segmental boneformation and BMSC/TCP constructs.CONCLUSION: This technique is an improvementover current methods, such as TCP substitution, andis useful for hard tissue reconstruction and inducingearlier bone union in defects.

  9. Relationships between serum osteoprotegerin, matrix metalloproteinase-2 levels and bone metabolism in postmenopausal women

    Institute of Scientific and Technical Information of China (English)

    DAI Yi; SHEN Lin

    2007-01-01

    Background Serum osteoprotegerin (OPG) and matrix metalloproteinase-2 (MMP-2) have been shown to play a role in bone metabolism by degrading the bone matrix. The present study was undertaken to compare OPG and MMP-2 with bone mineral density and three markers (alkaline phosphatase (AKP), calcium and phosphorus) in postmenopausal women in Wuhan.Methods Serum OPG, MMP-2, and AKP of 78 Chinese postmenopausal women aged 48 to 65 were measured using enzyme-linked immunosorbent assay (ELISA). Bone mineral density was measured with dual energy X-ray absorptiometry (DEXA), and serum calcium and phosphorus were measured by auto biochemical analysis.Results Serum OPG and MMP-2 concentrations were significantly higher in postmenopausal women with osteoporosis ((127.6±6.3) ng/L; (1388±121) μg/L)) than those in age-matched normal controls ((72.3±2.4) ng/L; (1126±141) μg/L,P<0.01). Negative relationships were found between serum OPG, MMP-2 levels and bone mineral density in osteoporotic women. Adjusted by age and body mass index (BMI), the correlation of MMP-2 with bone mineral density of the neck of the femur disappeared. In osteoporotic women, negative correlations between OPG, MMP-2 levels and serum calcium were found (r=-0.216; r=-0.269, P<0.05), but positive correlations between OPG and serum AKP, serum phosphorus (r=0.235; r=0.124, P<0.05).Conclusions Significant correlations exist between serum OPG, MMP-2 levels and bone metabolism in high bone turnover of postmenopausal osteoporotic women. The concentrations of serum OPG and MMP-2 increase possibly as a concomitant event in the high bone turnover state, such as postmenopausal osteoporosis. Therefore serum OPG and MMP-2 could be used as indicators for the bone metabolism in postmenopausal osteoporotic women.

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

    Science.gov (United States)

    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).

  11. Proof of direct radiogenic destruction of collagen in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Acil, Y.; Springer, I.N.; Gassling, P.; Warnke, P.H.; Acmaz, S.; Soenmez, T.T.; Wiltfang, J. [Univ. Hospital Schleswig-Holstein, Kiel (Germany). Dept. of Oral and Maxillofacial Surgery; Niehoff, P.; Kimmig, B. [Univ. Hospital Schleswig-Holstein, Kiel (DE). Dept. of Radiotherapy (Radiooncology); Lefteris, V. [Univ. of Athens Medical School (Greece). Dept. of Oral and Maxillofacial Surgery

    2007-07-15

    Background: Fibroses of vessels and soft tissue are side effects of radiotherapy. The authors assumed that there was an immediate direct radiogenic damage of collagen of bone, periosteum and skin. Material and Methods: 15 porcine jaws samples (group 1) were exposed to a total dose of 60 Gy (cobalt-60, 2 Gy/day, five fractions/week). 15 jaws samples were stored accordingly (group 2, no irradiation, control). Collagen fragments of bone, periosteum and skin samples of groups 1 and 2 were isolated by ultrafiltration. Collagen types were characterized by SDS-PAGE measurement of the mature collagen cross-links hydroxylysylpyridinoline (HP) and lysylpyridinoline (LP) by high-performance liquid chromatography (HPLC) and analysis of hydroxyproline (Hyp) was used to determine the ratio of the amount of collagen fragments from irradiated as opposed to nonirradiated samples. Results: The concentrations of HP, LP and Hyp in ultrafiltrates of probes of irradiated bone, periosteum and skin were markedly increased (average factors for bone: 3.69, 1.84, and 3.40, respectively; average factors for periosteum: 1.55, 1.41, and 1.77, respectively; average factors for skin: 1.55, 1.60, and 2.23, respectively) as compared to nonirradiated probes. SDS-PAGE did show collagen types I and V in nonirradiated bone, I and III in nonirradiated skin, and I in nonirradiated periosteum samples. In irradiated samples, smeared bands illustrated fragmentation of the collagen molecule. Conclusion: The increased concentrations of HP, LP and Hyp in ultrafiltrates indicated increased concentrations of split collagen. Direct and instant radiogenic damage of (extracellular matrix of) bone, periosteum and skin tissue collagen could be demonstrated. (orig.)

  12. Collagen structure regulates fibril mineralization in osteogenesis as revealed by cross-link patterns in calcifying callus

    NARCIS (Netherlands)

    Wassen, M.H.M.; Lammens, J.; Tekoppele, J.M.; Sakkers, R.J.B.; Liu, Z.; Verbout, A.J.; Bank, R.A.

    2000-01-01

    Although >80% of the mineral in mammalian bone is present in the collagen fibrils, limited information is available about factors that determine a proper deposition of mineral. This study investigates whether a specific collagen matrix is required for fibril mineralization. Calcifying callus from do

  13. Clinical evaluation of the efficacy of a GTR membrane (HEALIGUIDE® and demineralised bone matrix (OSSEOGRAFT® as a space maintainer in the treatment of Miller′s Class I gingival recession

    Directory of Open Access Journals (Sweden)

    S Nanditha

    2011-01-01

    Full Text Available Background: Periodontal plastic surgical procedures aimed at coverage of exposed root surface have evolved into routine treatment modalities. The present study was designed to evaluate the effectiveness and predictability of using a collagen barrier along with a demineralized bone matrix in the treatment of recession defects in a single surgical procedure. Materials and Methods: Seventeen patients with Miller′s class I recession were treated with a combination of a collagen barrier used along with a bone graft and coronally advanced flap technique. Clinical parameters were recorded at baseline, 3 months, 6 months, and 9 months. Results: The study showed a highly significant reduction in the recession depth (70.29 ± 21.96% at the end of the study. This study showed that the use of this technique for recession coverage is highly predictable and highly esthetic root coverage can be obtained.

  14. Bone formation and degradation behavior of nanocrystalline hydroxyapatite with or without collagen-type 1 in osteoporotic bone defects - an experimental study in osteoporotic goats.

    Science.gov (United States)

    Alt, Volker; Cheung, Wing Hoi; Chow, Simon K H; Thormann, Ulrich; Cheung, Edmond N M; Lips, Katrin S; Schnettler, Reinhard; Leung, Kwok-Sui

    2016-06-01

    The intention of the current work is to assess new bone formation and degradation behavior of nanocrystalline hydroxyapatite with (HA/col-1) or without collagen-type I (HA) in osteoporotic metaphyseal bone defects in goats. After ovariectomy and special low-calcium diet for three months, 3 drill hole defects in the vertebrae of L3, L4, L5, 4 drill hole defects in the right and left iliac crest and 1 drill hole defect at the distal femur were created in three Chinese mountain goats with a total of 24 defects. The defects were either filled with one of the biomaterials or left empty (empty defect control group). After 42 days, the animals were euthanized and the samples were assessed for new bone formation using high-resolution peripheral quantitative computed tomography (HR-pQCT) and histomorphometry with 2 regions of interest. Detail histology, enzymehistochemistry and immunohistochemistry as well as connexin-43 in situ hybridization and transmission electron microscopy were carried out for evaluation of degradation behavior of the materials and cellular responses of the surrounding tissue in respect to the implants. HR-pQCT showed the highest BV/TV ratio (p = 0.008) and smallest trabecular spacing (p = 0.005) for HA compared to the other groups in the region of interest at the interface with 1mm distance to the initially created defect. The HA/col-1 yielded the highest connectivity density (Conn.D) (p = 0.034) and the highest number of trabeculae (Tb.N) (p = 0.002) compared to the HA and the control group. Histomorphometric analysis for the core region of the initially created defect revealed a statistically higher new bone formation in the HA (p = 0.001) and HA/col-1 group (p = 0.001) compared to the empty defect group including all defect sites. This result was confirmed for site specific analysis with significant higher new bone formation for the HA group for vertebral defects compared to the empty defect group (p = 0.029). For the interface region, no

  15. Tumor necrosis factor-α-accelerated degradation of type I collagen in human skin is associated with elevated matrix metalloproteinase (MMP)-1 and MMP-3 ex vivo

    DEFF Research Database (Denmark)

    Ågren, Magnus S; Schnabel, Reinhild; Christensen, Lise H;

    2015-01-01

    Tumor necrosis factor (TNF)-α induces matrix metalloproteinases (MMPs) that may disrupt skin integrity. We have investigated the effects and mechanisms of exogenous TNF-α on collagen degradation by incubating human skin explants in defined serum-free media with or without TNF-α (10ng...... activator MMP-3. Type I collagen degradation correlated with MMP-3 tissue levels (rs=0.68, pcollagen formation was down-regulated in cultured compared with native skin explants but was not reduced further by TNF-α. TNF-α had no significant...... effect on epidermal apoptosis. Our data indicate that TNF-α augments collagenolytic activity of MMP-1, possibly through up-regulation of MMP-3 leading to gradual loss of type I collagen in human skin....

  16. Low-Temperature Additive Manufacturing of Biomimic Three-Dimensional Hydroxyapatite/Collagen Scaffolds for Bone Regeneration.

    Science.gov (United States)

    Lin, Kai-Feng; He, Shu; Song, Yue; Wang, Chun-Mei; Gao, Yi; Li, Jun-Qin; Tang, Peng; Wang, Zheng; Bi, Long; Pei, Guo-Xian

    2016-03-23

    Low-temperature additive manufacturing (AM) holds promise for fabrication of three-dimensional (3D) scaffolds containing bioactive molecules and/or drugs. Due to the strict technical limitations of current approaches, few materials are suitable for printing at low temperature. Here, a low-temperature robocasting method was employed to print biomimic 3D scaffolds for bone regeneration using a routine collagen-hydroxyapatite (CHA) composite material, which is too viscous to be printed via normal 3D printing methods at low temperature. The CHA scaffolds had excellent 3D structure and maintained most raw material properties after printing. Compared to nonprinted scaffolds, printed scaffolds promoted bone marrow stromal cell proliferation and improved osteogenic outcome in vitro. In a rabbit femoral condyle defect model, the interconnecting pores within the printed scaffolds facilitated cell penetration and mineralization before the scaffolds degraded and enhanced repair, compared to nonprinted CHA scaffolds. Additionally, the optimal printing parameters for 3D CHA scaffolds were investigated; 600-μm-diameter rods were optimal in terms of moderate mechanical strength and better repair outcome in vivo. This low-temperature robocasting method could enable a variety of bioactive molecules to be incorporated into printed CHA materials and provides a method of bioprinting biomaterials without compromising their natural properties. PMID:26930140

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

    Science.gov (United States)

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

    2014-02-01

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

  18. Use of a Collagen Matrix as a Substitute for Free Mucosal Grafts in Pre-Prosthetic Surgery: 1 Year Results From a Clinical Prospective Study on 15 Patients

    Science.gov (United States)

    Maiorana, Carlo; Beretta, Mario; Pivetti, Luca; Stoffella, Enrico; Grossi, Giovanni B.; Herford, Alan S.

    2016-01-01

    Background: The presence of keratinized tissue around dental implants is more than desirable either from a functional and aesthetic point of view, making soft tissue grafting a common practice in implant rehabilitation. Autogenous soft tissue grafting procedures are usually associated with high morbidity. Aim of this study was to assess the efficacy of a xenogeneic collagen matrix as a substitute for soft tissue grafting around dental implants. Methods: 15 consecutive patients underwent a vestibuloplasty and grafting, both in the mandible and the maxilla, with a collagen matrix. Results: The primary endpoint was to evaluate the resorption of the graft along with the re-epithelization grafted area. The percentage of the resorption was 44,4%, with a mean gain in vestibular height of 3 mm. Secondary endpoints evaluated the clinical appearance, the hemostatic effect and the post-operative pain. All subjects referred minimal pain with no bleeding. No adverse reaction nor infection were noted. Conclusion: This study showed that the used collagen matrix can find major interest in those patients who need a greater aesthetic outcome as the matrix has a perfect integration with the surrounding tissues. Furthermore it is strongly recommended for those patients who can bear little pain. Clinical Significance: Post-operative morbidity of autologous grafts is the biggest concern of this type of surgery. The possibility to use a soft tissue substitute is a great achievement as morbidity decreases and bigger areas can be treated in a single surgery. The present study showed the efficacy of a collagen matrix as this kind of substitute. PMID:27583050

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

    Science.gov (United States)

    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.

  20. Effect of macrophage and matrix metalloproteinase-9 on proliferation of pulmonary fibroblast and synthesis of collagen IV

    International Nuclear Information System (INIS)

    Objective: To explore pathogenetic mechanism in initiation of radiation-induced pulmonary fibrosis. Methods: Alveolar macrophages in Wistar rats irradiated by 60Co γ-ray were collected by alveolar lavage; condition medium was prepared for stimulating human lung fibroblast (HLF) proliferation; HLF proliferation activity was determined by MTT method; collagen IV (Col IV) in HLF was determined by Western blot; the activity of matrix metalloproteinase-9 (MMP-9) was determined by zymography. Results: HLF proliferation activity was significantly increased after stimulation of condition medium, and the increase was most evident within 48-72 hs. Col IV synthesis in HLF was increased and reached a peak at 12 h after stimulation and then began to decrease. MMP-9 activity began to increase at 12 h and reached a peak at 48 h and then decreased after 72 h. Conclusions: Cobalt-60 gamma ray irradiation of 20 Gy can stimulate secretion of some cytokines in alveolar macrophage to promote pulmonary interstitial fibroblast proliferation and synthesis of Col IV . Col IV can stimulate MMP-9 increase; MMP-9 can degrade excess Col IV. Such changes are involved in remodeling process of early pulmonary injury. (authors)

  1. A Randomized Comparative Study of Two Techniques to Optimize the Root Coverage Using a Porcine Collagen Matrix.

    Science.gov (United States)

    Reino, Danilo Maeda; Maia, Luciana Prado; Fernandes, Patrícia Garani; Souza, Sergio Luis Scombatti de; Taba Junior, Mario; Palioto, Daniela Bazan; Grisi, Marcio Fermandes de Moraes; Jr, Arthur Belém Novaes

    2015-10-01

    The aim of this randomized controlled clinical study was to compare the extended flap technique (EFT) with the coronally advanced flap technique (CAF) using a porcine collagen matrix (PCM) for root coverage. Twenty patients with two bilateral gingival recessions, Miller class I or II on non-molar teeth were treated with CAF+PCM (control group) or EFT+PCM (test group). Clinical measurements of probing pocket depth (PPD), clinical attachment level (CAL), recession height (RH), keratinized tissue height (KTH), keratinized mucosa thickness (KMT) were determined at baseline, 3 and 6 months post-surgery. At 6 months, the mean root coverage for test group was 81.89%, and for control group it was 62.80% (p<0.01). The change of recession depth from baseline was statistically significant between test and control groups, with an mean of 2.21 mm gained at the control sites and 2.84 mm gained at the test sites (p=0.02). There were no statistically significant differences for KTH, PPD or CAL comparing the two therapies. The extended flap technique presented better root coverage than the coronally advanced flap technique when PCM was used. PMID:26647926

  2. Artesunate modulates expression of matrix metalloproteinases and their inhibitors as well as collagen-IV to attenuate pulmonary fibrosis in rats.

    Science.gov (United States)

    Wang, Y; Huang, G; Mo, B; Wang, C

    2016-01-01

    The aim of this study was to determine the effect of artesunate on extracellular matrix (ECM) accumulation and the expression of collagen-IV, matrix metalloproteinase (MMP), and tissue inhibitor of matrix metalloproteinase (TIMP) to understand the pharmacological role of artesunate in pulmonary fibrosis. Eighty Sprague-Dawley rats were randomly assigned to four groups that were administered saline alone, bleomycin (BLM) alone, BLM + artesunate, or artesunate alone for 28 days. Lung tissues from 10 rats in each group were used to obtain lung fibroblast (LF) primary cells, and the rest were used to analyze protein expression. The mRNA expression of collagen-IV, MMP-2, MMP-9, TIMP-1, and TIMP-2 in lung fibroblasts was detected by real-time quantitative reverse transcriptase polymerase chain reaction. The protein levels of collagen-IV, MMP-2, MMP-9, TIMP-1, and TIMP-2 protein in lung tissues were analyzed by western blotting. Artesunate treatment alleviated alveolitis and pulmonary fibrosis induced by bleomycin in rats, as indicated by a decreased lung coefficient and improvement of lung tissue morphology. Artesunate treatment also led to decreased collagen-IV protein levels, which might be a result of its downregulated expression and increased MMP-2 and MMP-9 protein and mRNA levels. Increased TIMP-1 and TIMP- 2 protein and mRNA levels were detected after artesunate treatment in lung tissues and primary lung fibroblast cells and may contribute to enhanced activity of MMP-2 and -9. These findings suggested that artesunate attenuates alveolitis and pulmonary fibrosis by regulating expression of collagen-IV, TIMP-1 and 2, as well as MMP-2 and -9, to reduce ECM accumulation. PMID:27323108

  3. In vivo effects of modification of hydroxyapatite/collagen composites with and without chondroitin sulphate on bone remodeling in the sheep tibia.

    Science.gov (United States)

    Schneiders, Wolfgang; Reinstorf, Antje; Biewener, Achim; Serra, Alexandrè; Grass, Renè; Kinscher, Michael; Heineck, Jan; Rehberg, Sebastian; Zwipp, Hans; Rammelt, Stefan

    2009-01-01

    The addition of chondroitin sulphate (CS) to bone cements with calcium phosphate has lead to an enhancement of bone remodeling and an increase in new bone formation in small animals. The goal of this study was to verify the effect of CS in bone cements in a large animal model simulating a clinically relevant situation of a segmental cortical defect of a critical size on bone-implant interaction and bone remodeling. The influence of adding CS to hydroxyapatite/collagen (HA/Col) composites on host response was assessed in a standard sheep tibia model. A midshaft defect of 3 cm was created in the tibiae of 14 adult female sheep. The defect was filled with a HA/Col cement cylinder in seven animals and with a CS-modified hydroxyapatite/collagen (HA/Col/CS) cement cylinder in seven animals. In all cases the tibia was stabilized with an interlocked universal tibial nail. The animals in each group were analyzed with X-rays, CT scans, histology, immunohistochemistry, and enzymehistochemistry, as well as histomorphometric measurements. The X-ray investigation showed a significantly earlier callus reaction around the HA/Col/CS implants compared to HA/Col alone. The amount of newly formed bone at the end point of the experiment was significantly larger around HA/Col/CS cylinders both in the CT scan and in the histomorphometric analysis. There were still TRAP-positive osteoclasts around the HA/Col implants after 3 months. The number of osteopontin-positive osteoblasts and the direct bone contact were significantly higher around HA/Col/CS implants. We conclude that addition of CS enhances bone remodeling and new bone formation around HA/Col composites.

  4. The collagen microfibil model as a tool for leather scientists

    Science.gov (United States)

    Collagen, a structural protein of the extracellular matrix, gives strength and form to the skin, tendons, bones, cornea and teeth of mammals. The discovery by early humans that the skin of an animal, slaughtered for meat, could be preserved by exposing it to smoke or rubbing with fat, led to the pr...

  5. In vitro cartilage production using an extracellular matrix-derived scaffold and bone marrow-derived mesenchymal stem cells

    Institute of Scientific and Technical Information of China (English)

    ZHAO Yan-hong; YANG Qiang; XIA Qun; PENG Jiang; LU Shi-bi; GUO Quan-yi; MA Xin-long

    2013-01-01

    Background Cartilage repair is a challenging research area because of the limited healing capacity of adult articular cartilage.We had previously developed a natural,human cartilage extracellular matrix (ECM)-derived scaffold for in vivo cartilage tissue engineering in nude mice.However,before these scaffolds can be used in clinical applications in vivo,the in vitro effects should be further explored.Methods We produced cartilage in vitro using a natural cartilage ECM-derived scaffold.The scaffolds were fabricated by combining a decellularization procedure with a freeze-drying technique and were characterized by scanning electron microscopy (SEM),micro-computed tomography (micro-CT),histological staining,cytotoxicity assay,biochemical and biomechanical analysis.After being chondrogenically induced,the induction results of BMSCs were analyzed by histology and Immunohisto-chemistry.The attachment and viability assessment of the cells on scaffolds were analyzed using SEM and LIVE/DEAD staining.Cell-scaffold constructs cultured in vitro for 1 week and 3 weeks were analyzed using histological and immunohistochemical methods.Results SEM and micro-CT revealed a 3-D interconnected porous structure.The majority of the cartilage ECM was found in the scaffold following the removal of cellular debris,and stained positive for safranin O and collagen Ⅱ.Viability staining indicated no cytotoxic effects of the scaffold.Biochemical analysis showed that collagen content was (708.2±44.7)μg/mg,with GAG (254.7±25.9) μg/mg.Mechanical testing showed the compression moduli (E) were (1.226±0.288) and (0.052±0.007) MPa in dry and wet conditions,respectively.Isolated canine bone marrow-derived stem cells (BMSCs) were induced down a chondrogenic pathway,labeled with PKH26,and seeded onto the scaffold.Immunofluorescent staining of the cell-scaffold constructs indicated that chondrocyte-like cells were derived from seeded BMSCs and excreted ECM.The cell-scaffold constructs contained

  6. Ridge preservation with acellular dermal matrix and anorganic bone matrix cell-binding peptide P-15 after tooth extraction in humans. A histologic and morphometric study

    OpenAIRE

    Arthur B. Novaes Jr.; Patricia Garani Fernandes; Flávia Adelino Suaid; Marcio Fernando de Moraes Grisi; Sergio Luis Scombatti de Souza; Mario Taba Jr.; Daniela Bazan Palioto; Valdir Antonio Muglia

    2012-01-01

    Aim: The aim of this study was to analyze by histomorphometric parameters the use of acellular dermal matrix (ADM) with or without anorganic bovine bone matrix (ABM) / synthetic cell-binding peptide P-15 in the formation of bone in human alveoli. Materials and methods: Eighteen patients in need of extraction of maxillary anterior teeth were selected and randomly assigned to the test group (ADM plus ABM/P-15) or the control group (ADM only). Histomorphometric measurements and histological a...

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

    Science.gov (United States)

    2016-01-01

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

  8. Prdm5 Regulates Collagen Gene Transcription by Association with RNA Polymerase II in Developing Bone

    DEFF Research Database (Denmark)

    Galli, Giorgio Giacomo; Honnens de Lichtenberg, Kristian; Carrara, Matteo;

    2012-01-01

    PRDM family members are transcriptional regulators involved in tissue specific differentiation. PRDM5 has been reported to predominantly repress transcription, but a characterization of its molecular functions in a relevant biological context is lacking. We demonstrate here that Prdm5 is highly e...... transcriptional program necessary to the proper assembly of osteoblastic extracellular matrix....

  9. Conditional Knockout of the MicroRNA 17-92 Cluster in Type-I Collagen-Expressing Cells Decreases Alveolar Bone Size and Incisor Tooth Mechanical Properties.

    Science.gov (United States)

    Ibrahim, M; Mohan, S; Xing, M J; Kesavan, C

    2016-01-01

    To test the role of the miR17-92 (miR) cluster in dental bones, we evaluated the incisor tooth phenotype by micro-CT in 5- and 12-week-old conditional knockout (CKO) mice deficient in the miR17-92 cluster in type-I collagen-expressing cells and bone strength by finite element analysis. The incisor teeth of CKO mice showed a 23-30 % reduction in tissue volume and bone volume. Accordingly, the stiffness and failure load of incisor teeth assessed by finite element analysis showed an 18-40 % decrease in CKO compared to wild-type mice. A positive correlation between bone parameters and strength data suggests that the decreased mechanical properties of incisor teeth are due to decreased tissue volume and bone volume. Subsequently, we found that the width of alveolar bone was reduced by 25 % with a 16 % increase in periodontal ligament space, suggesting that the CKO mice are more susceptible to tooth movement. Since alveolar bone is populated primarily by osteoblast lineage cells, it is likely that the reduction in periosteal expansion of alveolar bone in the lower jaw of CKO mice results from decreased periosteal bone formation. Overall, our phenotype analysis demonstrates that the miR17-92 cluster is essential for development and maintenance of tooth strength by regulating its tooth size.

  10. Conditional Knockout of the MicroRNA 17-92 Cluster in Type-I Collagen-Expressing Cells Decreases Alveolar Bone Size and Incisor Tooth Mechanical Properties.

    Science.gov (United States)

    Ibrahim, M; Mohan, S; Xing, M J; Kesavan, C

    2016-01-01

    To test the role of the miR17-92 (miR) cluster in dental bones, we evaluated the incisor tooth phenotype by micro-CT in 5- and 12-week-old conditional knockout (CKO) mice deficient in the miR17-92 cluster in type-I collagen-expressing cells and bone strength by finite element analysis. The incisor teeth of CKO mice showed a 23-30 % reduction in tissue volume and bone volume. Accordingly, the stiffness and failure load of incisor teeth assessed by finite element analysis showed an 18-40 % decrease in CKO compared to wild-type mice. A positive correlation between bone parameters and strength data suggests that the decreased mechanical properties of incisor teeth are due to decreased tissue volume and bone volume. Subsequently, we found that the width of alveolar bone was reduced by 25 % with a 16 % increase in periodontal ligament space, suggesting that the CKO mice are more susceptible to tooth movement. Since alveolar bone is populated primarily by osteoblast lineage cells, it is likely that the reduction in periosteal expansion of alveolar bone in the lower jaw of CKO mice results from decreased periosteal bone formation. Overall, our phenotype analysis demonstrates that the miR17-92 cluster is essential for development and maintenance of tooth strength by regulating its tooth size. PMID:27643583

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

    OpenAIRE

    Um, In-Woong; Hwang, Suk-Hyun; Kim, Young-Kyun; Kim, Moon-Young; Jun, Sang-Ho; Ryu, Jae-Jun; Jang, Hyon-Seok

    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...

  12. Bone neoformation in defects treated with fibrin platelet rich membrane versus collagen membrane: a histomorphometric study in rabbit’s femurs.

    Directory of Open Access Journals (Sweden)

    Edwin Jonathan Meza

    2015-02-01

    Full Text Available The aim of the present research was to compare the bone neoformation in bone defects treated with platelet rich fibrin (PRF and collagen membrane (CM, after 3 and 5 weeks for which two bone defects were created of 4 mm width and 6 mm depth in the left femur distal diaphysis of New Zeland rabbits (n = 12. The subjects were randomly allocated in 2 groups. One of the defects was covered with a platelet rich fibrin membrane (Centrifuged resorbable Autologous blood biopolymer without biochemical modification or collagen membrane (gold standard – Neo Mem. The second defect was left uncovered (NC. The rabbits were sacrified after 3 and 5 weeks (3 rabbits per period. The femur was completely removed and they were processed histomophometrically. The bone neoformation analysis was performed through a differential points counting. The data was statistically analyzed (ANOVA, Tukey. The histomorphometric results showed that bone neoformation of the defects treated with PRF after 3 weeks was equivalent to the neoformation of the CM (p

  13. Aragonite crystals grown on bones by reaction of CO2 with nanostructured Ca(OH)2 in the presence of collagen. Implications in archaeology and paleontology.

    Science.gov (United States)

    Natali, Irene; Tempesti, Paolo; Carretti, Emiliano; Potenza, Mariangela; Sansoni, Stefania; Baglioni, Piero; Dei, Luigi

    2014-01-21

    The loss of mechanical properties affecting archeological or paleontological bones is often caused by demineralization processes that are similar to those driving the mechanisms leading to osteoporosis. One simple way to harden and to strengthen demineralized bone remains could be the in situ growth of CaCO3 crystals in the aragonite polymorph - metastable at atmospheric pressure -which is known to have very strong mechanical strength in comparison with the stable calcite. In the present study the controlled growth of aragonite crystals was achieved by reaction between atmospheric CO2 and calcium hydroxide nanoparticles in the presence of collagen within the deteriorated bones. In a few days the carbonation of Ca(OH)2 particles led to a mixture of calcite and aragonite, increasing the strength of the mineral network of the bone. Scanning electron microscopy coupled with energy dispersive X-ray spectroscopy (SEM-EDS) and Fourier transform infrared (FT-IR) spectrometry showed that aragonite crystallization was achieved. The effect of the aragonite crystal formation on the mechanical properties of the deteriorated bones was investigated by means of X-rays microtomography, helium porosimetry, atomic force microscopy (AFM), and Vickers microhardness techniques. All these data enabled to conclude that the strength of the bones increased of a factor of 50-70% with respect to the untreated bone. These results could have immediate impact for preserving archeological and paleontological bone remains.

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

    OpenAIRE

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

    2007-01-01

    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....

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

    Science.gov (United States)

    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

  16. The effects of glucocorticoid on microarchitecture, collagen, mineral and mechanical properties of sheep femur cortical bone

    DEFF Research Database (Denmark)

    Ding, Ming; Danielsen, Carl Christian; Overgaard, Søren

    2011-01-01

    of 3 months without treatment. Group 3 was left untreated and served as controls. All sheep received a restricted diet with low calcium and phosphorus. At sacrifice, cortical bone samples from the femur midshaft of each sheep were harvested, micro-CT scanned and subjected to three-point bending......In this study, 18 female skeletally mature sheep were randomly allocated into three groups of six each. Group 1 (glucocorticoid-1) received prednisolone treatment (0.60 mg/kg/day, five times weekly) for 7 months. Group 2 (glucocorticoid-2) received the same treatment regime followed by observation...... the groups, while there was a trend towards decreasing bending mechanical properties in the glucocorticoid-2 group. In conclusion, 7 months of glucocorticoid treatment with malnutrition had a significant impact on the cortical microarchitecture of the sheep femur midshaft. These observed changes occurred 3...

  17. Breakdown of cell-collagen networks through collagen remodeling

    OpenAIRE

    Iordan, Andreea; Duperray, Alain; Gérard, Anaïs; Grichine, Alexei; Verdier, Claude

    2010-01-01

    International audience Collagen model tissues are analyzed, which consist of cells embedded in a collagen matrix at different concentrations (of cells and collagen). Rheological properties are measured and complementary confocal microscopy analyses are carried out. An important feature is observed, corresponding to the breakdown of the collagen network (i.e. decrease in network elasticity) for high collagen concentrations, due to the presence of cells. Thanks to confocal microscopy, we sho...

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

    Science.gov (United States)

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

    2016-05-01

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

  19. MT1-MMP promotes cell growth and ERK activation through c-Src and paxillin in three-dimensional collagen matrix

    Energy Technology Data Exchange (ETDEWEB)

    Takino, Takahisa; Tsuge, Hisashi; Ozawa, Terumasa [Department of Molecular Virology and Oncology, Cancer Research Institute, Kanazawa University, Kakuma-machi, Kanazawa 920-1192 (Japan); Sato, Hiroshi, E-mail: vhsato@kenroku.kanazawa-u.ac.jp [Department of Molecular Virology and Oncology, Cancer Research Institute, Kanazawa University, Kakuma-machi, Kanazawa 920-1192 (Japan)

    2010-06-11

    Membrane-type 1 matrix metalloproteinase (MT1-MMP) is essential for tumor invasion and growth. We show here that MT1-MMP induces extracellular signal-regulated kinase (ERK) activation in cancer cells cultured in collagen gel, which is indispensable for their proliferation. Inhibition of MT1-MMP by MMP inhibitor or small interfering RNA suppressed activation of focal adhesion kinase (FAK) and ERK in MT1-MMP-expressing cancer cells, which resulted in up-regulation of p21{sup WAF1} and suppression of cell growth in collagen gel. Cell proliferation was also abrogated by the inhibitor against ERK pathway without affecting FAK phosphorylation. MT1-MMP and integrin {alpha}{sub v}{beta}{sub 3} were shown to be involved in c-Src activation, which induced FAK and ERK activation in collagen gel. These MT1-MMP-mediated signal transductions were paxillin dependent, as knockdown of paxillin reduced cell growth and ERK activation, and co-expression of MT1-MMP with paxillin induced ERK activation. The results suggest that MT1-MMP contributes to proliferation of cancer cells in the extracellular matrix by activating ERK through c-Src and paxillin.

  20. Efficacy of Mucograft vs Conventional Resorbable Collagen Membranes in Guided Bone Regeneration Around Standardized Calvarial Defects in Rats: An In Vivo Microcomputed Tomographic Analysis.

    Science.gov (United States)

    Basudan, Amani; Babay, Nadir; Ramalingam, Sundar; Nooh, Nasser; Al-Kindi, Mohammed; Al-Rasheed, Abdulaziz; Al-Hezaimi, Khalid

    2016-01-01

    The aim of this in vivo microcomputed tomographic (μCT) study was to compare the efficacy of Mucograft (MG) vs resorbable collagen membranes (RCMs) in facilitating guided bone regeneration (GBR) around standardized calvarial defects in rats. Forty female Wistar albino rats with a mean age and weight of 6 to 9 weeks and 250 to 300 g, respectively, were used. With the rats under general anesthesia, the skin over the calvaria was exposed using a full-thickness flap. A standardized calvarial defect with a 4.6-mm diameter was created in the left parietal bone. For treatment, the rats were randomly divided into four groups (n = 10 per group): (1) defects covered with MG (MG group); (2) defects covered with an RCM (RCM group); (3) defects filled with xenograft bone particles and covered by MG (MG + bone group); and (4) defects filled with xenograft bone particles and covered by an RCM (RCM + bone group). Primary closure was achieved using interrupted resorbable sutures. The animals underwent high-resolution, three-dimensional μCT scans at baseline and at 2, 4, 6, and 8 weeks after the surgical procedures. Data regarding volume and bone mineral density (BMD) of newly formed bone (NFB) and bone particles revealed an increase in the volume of NFB in all the groups from baseline to 8 weeks. The MG group had the lowest volume of NFB (mean ± standard deviation [SD], 1.32 ± 0.22 mm(3)). No significant differences in mean ± SD values for volume of NFB were observed between the RCM (3.50 ± 0.24 mm(3)) and MG + bone (3.87 ± 0.36 mm(3)) groups, but their values were significantly lower than that of the RCM + bone group (2.95 ± 0.15 mm(3), F = 131.91, dfN = 2, dfD = 27, P RCM group having the highest mean ± SD BMD of NFB (0.42 ± 0.05 g/mm(3)). Significant differences in the bone particle volume between the RCM + bone and MG + bone groups (F = 91.04, dfN = 1, dfD = 18, P RCM + bone group displaying greater reduction in both volume (36.8%) and BMD (19.7%) of bone particles

  1. The effect of Hydroxyapatite/collagen I composites, bone marrow aspirate and bone graft on fixation of bone implants in sheep

    DEFF Research Database (Denmark)

    Babiker, Hassan

    of bone implants.   Materials and Methods: Titanium alloy implants were inserted into bilateral femoral condyles of 8 skeletally mature sheep, four in each sheep. The implant has a circumferential gap of 2 mm. The gap was filled with: HA/coll; HA/coll-BMA; autograft or allograft. Allograft was served...

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  3. Conditional disruption of miR17-92 cluster in collagen type I-producing osteoblasts results in reduced periosteal bone formation and bone anabolic response to exercise.

    Science.gov (United States)

    Mohan, Subburaman; Wergedal, Jon E; Das, Subhashri; Kesavan, Chandrasekhar

    2015-02-01

    In this study, we evaluated the role of the microRNA (miR)17-92 cluster in osteoblast lineage cells using a Cre-loxP approach in which Cre expression is driven by the entire regulatory region of the type I collagen α2 gene. Conditional knockout (cKO) mice showed a 13-34% reduction in total body bone mineral content and area with little or no change in bone mineral density (BMD) by DXA at 2, 4, and 8 wk in both sexes. Micro-CT analyses of the femur revealed an 8% reduction in length and 25-27% reduction in total volume at the diaphyseal and metaphyseal sites. Neither cortical nor trabecular volumetric BMD was different in the cKO mice. Bone strength (maximum load) was reduced by 10% with no change in bone toughness. Quantitative histomorphometric analyses revealed a 28% reduction in the periosteal bone formation rate and in the mineral apposition rate but with no change in the resorbing surface. Expression levels of periostin, Elk3, Runx2 genes that are targeted by miRs from the cluster were decreased by 25-30% in the bones of cKO mice. To determine the contribution of the miR17-92 cluster to the mechanical strain effect on periosteal bone formation, we subjected cKO and control mice to 2 wk of mechanical loading by four-point bending. We found that the periosteal bone response to mechanical strain was significantly reduced in the cKO mice. We conclude that the miR17-92 cluster expressed in type I collagen-producing cells is a key regulator of periosteal bone formation in mice. PMID:25492928

  4. The X-Linked Inhibitor of Apoptosis Protein Inhibitor Embelin Suppresses Inflammation and Bone Erosion in Collagen Antibody Induced Arthritis Mice

    Directory of Open Access Journals (Sweden)

    Anak A. S. S. K. Dharmapatni

    2015-01-01

    Full Text Available Objective. To investigate the effect of Embelin, an inhibitor of X-Linked Inhibitor of Apoptosis Protein (XIAP, on inflammation and bone erosion in a collagen antibody induced arthritis (CAIA in mice. Methods. Four groups of mice (n=6 per group were allocated: CAIA untreated mice, CAIA treated with Prednisolone (10 mg/kg/day, CAIA treated with low dose Embelin (30 mg/kg/day, and CAIA treated with high dose Embelin (50 mg/kg/day. Joint inflammation was evaluated using clinical paw score and histological assessments. Bone erosion was assessed using micro-CT, tartrate resistant acid phosphatase (TRAP staining, and serum carboxy-terminal collagen crosslinks (CTX-1 ELISA. Immunohistochemistry was used to detect XIAP protein. TUNEL was performed to identify apoptotic cells. Results. Low dose, but not high dose Embelin, suppressed inflammation as reflected by lower paw scores (P<0.05 and lower histological scores for inflammation. Low dose Embelin reduced serum CTX-1 (P<0.05 and demonstrated lower histological score and TRAP counting, and slightly higher bone volume as compared to CAIA untreated mice. XIAP expression was not reduced but TUNEL positive cells were more abundant in Embelin treated CAIA mice. Conclusion. Low dose Embelin suppressed inflammation and serum CTX-1 in CAIA mice, indicating a potential use for Embelin to treat pathological bone loss.

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

    Directory of Open Access Journals (Sweden)

    Yang Wang

    2015-01-01

    Full Text Available 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

  6. Phosphodiesterase inhibition mediates matrix metalloproteinase activity and the level of collagen degradation fragments in a liver fibrosis ex vivo rat model

    Directory of Open Access Journals (Sweden)

    Veidal Sanne Skovgård

    2012-12-01

    Full Text Available Abstract Background Accumulation of extracellular matrix (ECM and increased matrix metalloproteinase (MMP activity are hallmarks of liver fibrosis. The aim of the present study was to develop a model of liver fibrosis combining ex vivo tissue culture of livers from CCl4 treated animals with an ELISA detecting a fragment of type III collagen generated in vitro by MMP-9 (C3M, known to be associated with liver fibrosis and to investigate cAMP modulation of MMP activity and liver tissue turnover in this model. Findings In vivo: Rats were treated for 8 weeks with CCl4/Intralipid. Liver slices were cultured for 48 hours. Levels of C3M were determined in the supernatants of slices cultured without treatment, treated with GM6001 (positive control or treated with IBMX (phosphodiesterase inhibitor. Enzymatic activity of MMP-2 and MMP-9 were studied by gelatin zymography. Ex vivo: The levels of serum C3M increased 77% in the CCl4-treated rats at week 8 (p 4-treated animals had highly increased MMP-9, but not MMP-2 activity, compared to slices derived from control animals. Conclusions We have combined an ex vivo model of liver fibrosis with measurement of a biochemical marker of collagen degradation in the condition medium. This technology may be used to evaluate the molecular process leading to structural fibrotic changes, as collagen species are the predominant structural part of fibrosis. These data suggest that modulation of cAMP may play a role in regulation of collagen degradation associated with liver fibrosis.

  7. Matrix Metalloproteinase 2 (MMP-2) Plays a Critical Role in the Softening of Common Carp Muscle during Chilled Storage by Degradation of Type I and V Collagens.

    Science.gov (United States)

    Xu, Chao; Wang, Cheng; Cai, Qiu-Feng; Zhang, Qian; Weng, Ling; Liu, Guang-Ming; Su, Wen-Jin; Cao, Min-Jie

    2015-12-30

    Matrix metalloproteinases (MMPs) are proposed to play important roles in the degradation of collagens, thus causing the post-mortem softening of fish muscle, although the specific mechanism remains largely unresolved. Previously, we reported the existence of gelatinase-like proteinases in common carp (Cyprinus carpio) muscle. The primary structures of these proteinases, however, have never been investigated. In the present study, two MMPs with molecular masses of 66 and 65 kDa were purified to homogeneity from common carp muscle by ammonium sulfate fractionation and a series of column chromatographies. Matrix-assisted laser desorption/ionization-tandem time-of-flight mass spectrometry (MALDI-TOF/TOF-MS/MS) analysis indicated that they are completely identical to MMP-2 from common carp. During chilled storage of common carp at 4 °C, the enzymatic activity of MMP-2 increased to 212% in 12 h while the texture profile increased over the first 2 h and gradually decreased. On the other hand, type V collagen was purified to homogeneity and a specific polyclonal antibody against this protein was prepared. Both type I and V collagens were effectively hydrolyzed by MMP-2 at 30 °C and even at 4 °C. Furthermore, injection of metalloproteinase proteinase inhibitor EDTA into the blood vessel of live common carp suppressed post-mortem tenderization significantly. All of these results confirmed that MMP-2 is a major proteinase responsible for the degradation of collagens, resulting in the softening of fish muscle during chilled storage. PMID:26653826

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

    Science.gov (United States)

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

    2016-02-01

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

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

    Science.gov (United States)

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

    2016-02-01

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

  10. The ratio 1660/1690 cm(-1 measured by infrared microspectroscopy is not specific of enzymatic collagen cross-links in bone tissue.

    Directory of Open Access Journals (Sweden)

    Delphine Farlay

    Full Text Available In postmenopausal osteoporosis, an impairment in enzymatic cross-links (ECL occurs, leading in part to a decline in bone biomechanical properties. Biochemical methods by high performance liquid chromatography (HPLC are currently used to measure ECL. Another method has been proposed, by Fourier Transform InfraRed Imaging (FTIRI, to measure a mature PYD/immature DHLNL cross-links ratio, using the 1660/1690 cm(-1 area ratio in the amide I band. However, in bone, the amide I band composition is complex (collagens, non-collagenous proteins, water vibrations and the 1660/1690 cm(-1 by FTIRI has never been directly correlated with the PYD/DHLNL by HPLC. A study design using lathyritic rats, characterized by a decrease in the formation of ECL due to the inhibition of lysyl oxidase, was used in order to determine the evolution of 1660/1690 cm(-1 by FTIR Microspectroscopy in bone tissue and compare to the ECL quantified by HPLC. The actual amount of ECL was quantified by HPLC on cortical bone from control and lathyritic rats. The lathyritic group exhibited a decrease of 78% of pyridinoline content compared to the control group. The 1660/1690 cm(-1 area ratio was increased within center bone compared to inner bone, and this was also correlated with an increase in both mineral maturity and mineralization index. However, no difference in the 1660/1690 cm(-1 ratio was found between control and lathyritic rats. Those results were confirmed by principal component analysis performed on multispectral infrared images. In bovine bone, in which PYD was physically destructed by UV-photolysis, the PYD/DHLNL (measured by HPLC was strongly decreased, whereas the 1660/1690 cm(-1 was unmodified. In conclusion, the 1660/1690 cm(-1 is not related to the PYD/DHLNL ratio, but increased with age of bone mineral, suggesting that a modification of this ratio could be mainly due to a modification of the collagen secondary structure related to the mineralization process.

  11. Small oscillatory accelerations, independent of matrix deformations, increase osteoblast activity and enhance bone morphology.

    Directory of Open Access Journals (Sweden)

    Russell Garman

    Full Text Available A range of tissues have the capacity to adapt to mechanical challenges, an attribute presumed to be regulated through deformation of the cell and/or surrounding matrix. In contrast, it is shown here that extremely small oscillatory accelerations, applied as unconstrained motion and inducing negligible deformation, serve as an anabolic stimulus to osteoblasts in vivo. Habitual background loading was removed from the tibiae of 18 female adult mice by hindlimb-unloading. For 20 min/d, 5 d/wk, the left tibia of each mouse was subjected to oscillatory 0.6 g accelerations at 45 Hz while the right tibia served as control. Sham-loaded (n = 9 and normal age-matched control (n = 18 mice provided additional comparisons. Oscillatory accelerations, applied in the absence of weight bearing, resulted in 70% greater bone formation rates in the trabeculae of the metaphysis, but similar levels of bone resorption, when compared to contralateral controls. Quantity and quality of trabecular bone also improved as a result of the acceleration stimulus, as evidenced by a significantly greater bone volume fraction (17% and connectivity density (33%, and significantly smaller trabecular spacing (-6% and structural model index (-11%. These in vivo data indicate that mechanosensory elements of resident bone cell populations can perceive and respond to acceleratory signals, and point to an efficient means of introducing intense physical signals into a biologic system without putting the matrix at risk of overloading. In retrospect, acceleration, as opposed to direct mechanical distortion, represents a more generic and safe, and perhaps more fundamental means of transducing physical challenges to the cells and tissues of an organism.

  12. Biological Assessment of a Calcium Silicate Incorporated Hydroxyapatite-Gelatin Nanocomposite: A Comparison to Decellularized Bone Matrix

    OpenAIRE

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

    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 ...

  13. Elevated carboxy terminal cross linked telopeptide of type I collagen in alcoholic cirrhosis: relation to liver and kidney function and bone metabolism

    DEFF Research Database (Denmark)

    Møller, S; Hansen, M; Hillingso, J;

    1999-01-01

    BACKGROUND: The carboxy terminal cross linked telopeptide of type I collagen (ICTP) has been put forward as a marker of bone resorption. Patients with alcoholic liver disease may have osteodystrophy. AIMS: To assess circulating and regional concentrations of ICTP in relation to liver dysfunction,...... osteopenia, the elevated ICTP in cirrhosis may therefore primarily reflect liver failure and hepatic fibrosis......., bone metabolism, and fibrosis. METHODS: In 15 patients with alcoholic cirrhosis and 20 controls, hepatic venous, renal venous, and femoral arterial concentrations of ICTP, and bone mass and metabolism were measured. RESULTS: Circulating ICTP was higher in patients with cirrhosis than in controls....... No overall significant hepatic disposal or production was found in the patient or control groups but slightly increased production was found in a subset of patients with advanced disease. Significant renal extraction was observed in the controls, whereas only a borderline significant extraction was observed...

  14. Conditional disruption of miR17-92 cluster in collagen type I-producing osteoblasts results in reduced periosteal bone formation and bone anabolic response to exercise

    OpenAIRE

    Mohan, Subburaman; Wergedal, Jon E.; Das, Subhashri; Kesavan, Chandrasekhar

    2014-01-01

    In this study, we evaluated the role of the microRNA (miR)17-92 cluster in osteoblast lineage cells using a Cre-loxP approach in which Cre expression is driven by the entire regulatory region of the type I collagen α2 gene. Conditional knockout (cKO) mice showed a 13–34% reduction in total body bone mineral content and area with little or no change in bone mineral density (BMD) by DXA at 2, 4, and 8 wk in both sexes. Micro-CT analyses of the femur revealed an 8% reduction in length and 25–27%...

  15. Type I collagen as an extracellular matrix for the in vitro growth of human small intestinal epithelium.

    Directory of Open Access Journals (Sweden)

    Ziyad Jabaji

    Full Text Available We previously reported in vitro maintenance and proliferation of human small intestinal epithelium using Matrigel, a proprietary basement membrane product. There are concerns over the applicability of Matrigel-based methods for future human therapies. We investigated type I collagen as an alternative for the culture of human intestinal epithelial cells.Human small intestine was procured from fresh surgical pathology specimens. Small intestinal crypts were isolated using EDTA chelation. Intestinal subepithelial myofibroblasts were isolated from a pediatric sample and expanded in vitro. After suspension in Matrigel or type I collagen gel, crypts were co-cultured above a confluent layer of myofibroblasts. Crypts were also grown in monoculture with exposure to myofibroblast conditioned media; these were subsequently sub-cultured in vitro and expanded with a 1∶2 split ratio. Cultures were assessed with light microscopy, RT-PCR, histology, and immunohistochemistry.Collagen supported viable human epithelium in vitro for at least one month in primary culture. Sub-cultured epithelium expanded through 12 passages over 60 days. Histologic sections revealed polarized columnar cells, with apical brush borders and basolaterally located nuclei. Collagen-based cultures gave rise to monolayer epithelial sheets at the gel-liquid interface, which were not observed with Matrigel. Immunohistochemical staining identified markers of differentiated intestinal epithelium and myofibroblasts. RT-PCR demonstrated expression of α-smooth muscle actin and vimentin in myofibroblasts and E-Cadherin, CDX2, villin 1, intestinal alkaline phosphatase, chromogranin A, lysozyme, and Lgr5 in epithelial cells. These markers were maintained through several passages.Type I collagen gel supports long-term in vitro maintenance and expansion of fully elaborated human intestinal epithelium. Collagen-based methods yield familiar enteroid structures as well as a new pattern of sheet

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

    Science.gov (United States)

    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

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

    Science.gov (United States)

    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

  18. Low dose BMP-2 treatment for bone repair using a PEGylated fibrinogen hydrogel matrix.

    Science.gov (United States)

    Ben-David, Dror; Srouji, Samer; Shapira-Schweitzer, Keren; Kossover, Olga; Ivanir, Eran; Kuhn, Gisela; Müller, Ralph; Seliktar, Dror; Livne, Erella

    2013-04-01

    Bone repair strategies utilizing resorbable biomaterial implants aim to stimulate endogenous cells in order to gradually replace the implant with functional repair tissue. These biomaterials should therefore be biodegradable, osteoconductive, osteoinductive, and maintain their integrity until the newly formed host tissue can contribute proper function. In recent years there has been impressive clinical outcomes for this strategy when using osteoconductive hydrogel biomaterials in combination with osteoinductive growth factors such as human recombinant bone morphogenic protein (hrBMP-2). However, the success of hrBMP-2 treatments is not without risks if the factor is delivered too rapidly and at very high doses because of a suboptimal biomaterial. Therefore, the aim of this study was to evaluate the use of a PEGylated fibrinogen (PF) provisional matrix as a delivery system for low-dose hrBMP-2 treatment in a critical size maxillofacial bone defect model. PF is a semi-synthetic hydrogel material that can regulate the release of physiological doses of hrBMP-2 based on its controllable physical properties and biodegradation. hrBMP-2 release from the PF material and hrBMP-2 bioactivity were validated using in vitro assays and a subcutaneous implantation model in rats. Critical size calvarial defects in mice were treated orthotopically with PF containing 8 μg/ml hrBMP-2 to demonstrate the capacity of these bioactive implants to induce enhanced bone formation in as little as 6 weeks. Control defects treated with PF alone or left empty resulted in far less bone formation when compared to the PF/hrBMP-2 treated defects. These results demonstrate the feasibility of using a semi-synthetic biomaterial containing small doses of osteoinductive hrBMP-2 as an effective treatment for maxillofacial bone defects. PMID:23375953

  19. Bone density of defects treated with lyophilized amniotic membrane versus collagen membrane: a tomographic and histomorfogenic study in rabbit´s femur

    Directory of Open Access Journals (Sweden)

    Liz Katty Ríos

    2014-09-01

    Full Text Available ABSTRACT The aim of this study was to compare the bone density of bone defects treated with lyophilizated amniotic membrane (LAM and collagen Membrane (CM, at 3 and 5 weeks. Two bone defects of 4 mm in diameter and 6 mm deep were created in left distal femoral diaphysis of New Zealand rabbits (n = 12. The animals were randomly divided into 2 groups. One of the defects was covered with lyophilized amniotic membrane (Rosa Chambergo Tissue Bank/National Institute of Child Health-IPEN, Lima, Peru or collagen Membrane (Dentium Co, Seoul, Korea. The second was left uncovered (NC. The rabbits were killed after 3 and 5 weeks (3 rabbits/period. The results showed a high bone density and repair of the defect by new bone. The tomographic study revealed that the bone density of the defects treated with LAM at 3 weeks was equivalent to the density obtained with CM and higher density compared with NC (p 0.05. The results show that lyophilizated amniotic membrane provides bone density equal or higher to the collagen membrane. RESUMEN El propósito de este estudio fue comparar la densidad ósea (DO de defectos óseos tratados con membrana amniótica liofilizada (MAL y membrana de colágeno (MC, a las 3 y 5 semanas. Se crearon dos defectos óseos, de 4 mm de diámetro y 6 mm de profundidad, en la diáfisis femoral distal izquierda de conejos Nueva Zelanda (n=12. Los animales fueron divididos aleatoriamente en 2 grupos. Uno de los defectos fue cubierto con membrana amniótica liofilizada (Banco de tejidos Rosa Chambergo/INSN-IPEN, Lima, Perú o membrana de colágeno (Dentium Co, Seoul, Korea. El segundo se dejó sin cubrir (NC. Los conejos fueron sacrificados después de 3 y 5 semanas (3 conejos/periodo. Los resultados mostraron una alta DO y reparación del defecto por hueso neoformado. El estudio tomográfico reveló que la DO de los defectos tratados con MAL a las 3 semanas fue comparable a la densidad obtenida con MC y mayor comparado con la densidad de NC (p

  20. EFEK KOLAGEN DARI BERBAGAI JENIS TULANG IKAN TERHADAP KUALITAS MIOFIBRIL PROTEIN IKAN SELAMA PROSES DEHIDRASI [Effect of Various Fish Bone Collagens on the Quality of Myofibril Fish Protein During Dehydration Process

    Directory of Open Access Journals (Sweden)

    Yudhomenggolo Sastro Darmanto*

    2012-06-01

    Full Text Available Increase in fish fillet export in Indonesia has caused an increase in its waste such as bones, spines, skin and entrails of fish. Fish bones can be processed by demineralization to produce collagen, an important food additive. The effect of addition of 5% of collagen obtained from fresh water, brackish water and sea water fish bone on the fish protein miofibril of grouper was investigated in this research. Water sorption isotherm, Ca-ATPase activity, gel strength, water holding capacity, folding test and viscosity during dehydration process were evaluated. The results showed that collagens made from various fish bones have different Ca-ATPase activity. The reduction rate of Ca-ATPase activity were in accordance with the reduction of water sorbtion isotherm, gel forming ability, water holding capacity, viscosity and folding test during dehydration process.

  1. Doses effects of zoledronic acid on mineral apatite and collagen quality of newly-formed bone in the rat's calvaria defect.

    Science.gov (United States)

    Olejnik, Cécile; Falgayrac, Guillaume; During, Alexandrine; Cortet, Bernard; Penel, Guillaume

    2016-08-01

    Due to their inhibitory effects on resorption, bisphosphonates are widely used in the treatment of diseases associated to an extensive bone loss. Yet, little is known about bisphosphonates effects on newly-formed bone quality. In the present study, adult male Sprague-Dawley rats (n=80) with a bone defect calvaria area were used and short-term effects of zoledronic acid (ZA) were studied on the healing bone area. Three ZA treatments were tested by using either: 1°) a low single dose (120μgZA/kg, n=10; equivalent to human osteoporosis treatment), 2°) a low fractionated doses (20μgZA/kg daily for 6days either a total of 120μg/kg, n=15), and 3°) a high fractionated doses, (100μgZA/kg weekly for 6weeks, n=15; equivalent to 6months of human bone metastasis treatment). For each treatment, a control "vehicle" treatment was performed (with an identical number of rats). After ZA administration, the intrinsic bone material properties were evaluated by quantitative backscattered electron imaging (qBEI) and Raman microspectroscopy. Neither single nor fractionated low ZA doses modify the intrinsic bone material properties of the newly-formed bone compared to their respective control animals. On the opposite, the high ZA treatment resulted in a significant decrease of the crystallinity (-25%, Porganization. In addition, we report here for the first time that high ZA doses decreased the hydroxyproline-to-proline ratio suggesting that ZA may affect the early collagen organization during the bone healing. PMID:27168397

  2. Resolving the bulk δ 15N values of ancient human and animal bone collagen via compound-specific nitrogen isotope analysis of constituent amino acids

    Science.gov (United States)

    Styring, Amy K.; Sealy, Judith C.; Evershed, Richard P.

    2010-01-01

    Stable nitrogen isotope analysis is a fundamental tool in assessing dietary preferences and trophic positions within contemporary and ancient ecosystems. In order to assess more fully the dietary contributions to human tissue isotope values, a greater understanding of the complex biochemical and physiological factors which underpin bulk collagen δ 15N values is necessary. Determinations of δ 15N values of the individual amino acids which constitute bone collagen are necessary to unravel these relationships, since different amino acids display different δ 15N values according to their biosynthetic origins. A range of collagen isolates from archaeological faunal and human bone ( n = 12 and 11, respectively), representing a spectrum of terrestrial and marine protein origins and diets, were selected from coastal and near-coastal sites at the south-western tip of Africa. The collagens were hydrolysed and δ 15N values of their constituent amino acids determined as N-acetylmethyl esters (NACME) via gas chromatography-combustion-isotope ratio mass spectrometry (GC-C-IRMS). The analytical approach employed accounts for 56% of bone collagen nitrogen. Reconstruction of bulk bone collagen δ 15N values reveals a 2‰ offset from bulk collagen δ 15N values which is attributable to the δ 15N value of the amino acids which cannot currently be determined by GC-C-IRMS, notably arginine which comprises 53% of the nitrogen unaccounted for (23% of the total nitrogen). The δ 15N values of individual amino acids provide insights into both the contributions of various amino acids to the bulk δ 15N value of collagen and the factors influencing trophic position and the nitrogen source at the base of the food web. The similarity in the δ 15N values of alanine, glutamate, proline and hydroxyproline reflects the common origin of their amino groups from glutamate. The depletion in the δ 15N value of threonine with increasing trophic level indicates a fundamental difference between

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

    Energy Technology Data Exchange (ETDEWEB)

    Martino, Mikaël M. [Osaka Univ. (Japan). Immunology Frontier Research Center; Briquez, Priscilla S. [Ecole Polytechnique Federale de Lausanne (Switzerland). Inst. of Bioengineering; Maruyama, Kenta [Osaka Univ. (Japan). Immunology Frontier Research Center; Hubbell, Jeffrey A. [Ecole Polytechnique Federale de Lausanne (Switzerland). Inst. of Bioengineering; Univ. of Chicago, IL (United States). Inst. for Molecular Engineering; Argonne National Lab. (ANL), Argonne, IL (United States)

    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.

  4. Contribution of matrix vesicles and alkaline phosphatase to ectopic bone formation

    Directory of Open Access Journals (Sweden)

    Ciancaglini P.

    2006-01-01

    Full Text Available Endochondral calcification involves the participation of matrix vesicles (MVs, but it remains unclear whether calcification ectopically induced by implants of demineralized bone matrix also proceeds via MVs. Ectopic bone formation was induced by implanting rat demineralized diaphyseal bone matrix into the dorsal subcutaneous tissue of Wistar rats and was examined histologically and biochemically. Budding of MVs from chondrocytes was observed to serve as nucleation sites for mineralization during induced ectopic osteogenesis, presenting a diameter with Gaussian distribution with a median of 306 ± 103 nm. While the role of tissue-nonspecific alkaline phosphatase (TNAP during mineralization involves hydrolysis of inorganic pyrophosphate (PPi, it is unclear how the microenvironment of MV may affect the ability of TNAP to hydrolyze the variety of substrates present at sites of mineralization. We show that the implants contain high levels of TNAP capable of hydrolyzing p-nitrophenylphosphate (pNPP, ATP and PPi. The catalytic properties of glycosyl phosphatidylinositol-anchored, polidocanol-solubilized and phosphatidylinositol-specific phospholipase C-released TNAP were compared using pNPP, ATP and PPi as substrates. While the enzymatic efficiency (k cat/Km remained comparable between polidocanol-solubilized and membrane-bound TNAP for all three substrates, the k cat/Km for the phosphatidylinositol-specific phospholipase C-solubilized enzyme increased approximately 108-, 56-, and 556-fold for pNPP, ATP and PPi, respectively, compared to the membrane-bound enzyme. Our data are consistent with the involvement of MVs during ectopic calcification and also suggest that the location of TNAP on the membrane of MVs may play a role in determining substrate selectivity in this micro-compartment.

  5. Location of 64K collagen producer chondrocytes in developing chicken embryo tibiae

    International Nuclear Information System (INIS)

    The synthesis of a new low-molecular-weight collagen by cultured chicken embryo chondrocytes has been recently demonstrated. In this paper the authors report results on the location of chondrocytes synthesizing this new collagen (64K collagen) in the developing chicken embryo. The 64K collagen is synthesized in very large amounts by cells concentrated at the diaphysis of 9-day-old and at the epiphysis of 17-day-old embryo tibiae. These regions are characterized by a remodeling of the cartilage matrix leading to the replacement of the cartilage with bone tissue; therefore, this collagen appears to be a marker of a specific developmental stage of chondrocytes. The origin of cells competent for the synthesis of the 64K collagen is also discussed

  6. Platelet-derived growth factor type BB and collagen matrix for soft tissue reconstruction after muco-epidermoid carcinoma removal: A possible therapeutic option

    Directory of Open Access Journals (Sweden)

    Marco Cicciù

    2015-01-01

    Full Text Available Muco-epidermoid carcinoma (MEC is a rare malignant tumor occurring in major and minor salivary glands. The described case shows a patient undergoing tumor resection without neck dissection. A quick diagnosis performed through clinical investigation and incisional biopsy revealed the nature of the tumor. A porcine collagen matrix was applied after the surgery in order to improve soft tissue healing. The matrix was saturated with platelet-derived growth factor type BB in order to favorite healing process and then fixed on the palate with a dental support device. Follow-up visit performed at first, second, and third weeks highlighted a quick healing of oral mucosa. Here reported is a case of a 34-year-old man who developed a muco-epidermoid oral carcinoma localized in the left upper jaw palatal side. The clinical, radiographic, and histopathologic findings, plus differential diagnoses of the case and reconstructive treatment options are also presented.

  7. Molecular crowding of collagen: a pathway to produce highly-organized collagenous structures.

    Science.gov (United States)

    Saeidi, Nima; Karmelek, Kathryn P; Paten, Jeffrey A; Zareian, Ramin; DiMasi, Elaine; Ruberti, Jeffrey W

    2012-10-01

    Collagen in vertebrate animals is often arranged in alternating lamellae or in bundles of aligned fibrils which are designed to withstand in vivo mechanical loads. The formation of these organized structures is thought to result from a complex, large-area integration of individual cell motion and locally-controlled synthesis of fibrillar arrays via cell-surface fibripositors (direct matrix printing). The difficulty of reproducing such a process in vitro has prevented tissue engineers from constructing clinically useful load-bearing connective tissue directly from collagen. However, we and others have taken the view that long-range organizational information is potentially encoded into the structure of the collagen molecule itself, allowing the control of fibril organization to extend far from cell (or bounding) surfaces. We here demonstrate a simple, fast, cell-free method capable of producing highly-organized, anistropic collagen fibrillar lamellae de novo which persist over relatively long-distances (tens to hundreds of microns). Our approach to nanoscale organizational control takes advantage of the intrinsic physiochemical properties of collagen molecules by inducing collagen association through molecular crowding and geometric confinement. To mimic biological tissues which comprise planar, aligned collagen lamellae (e.g. cornea, lamellar bone or annulus fibrosus), type I collagen was confined to a thin, planar geometry, concentrated through molecular crowding and polymerized. The resulting fibrillar lamellae show a striking resemblance to native load-bearing lamellae in that the fibrils are small, generally aligned in the plane of the confining space and change direction en masse throughout the thickness of the construct. The process of organizational control is consistent with embryonic development where the bounded planar cell sheets produced by fibroblasts suggest a similar confinement/concentration strategy. Such a simple approach to nanoscale

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

    Science.gov (United States)

    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

  9. Approach to the human diet of the punic population of Can Marines (Ibiza. C an N stable isotope analysis on bone collagen

    Directory of Open Access Journals (Sweden)

    Domingo Carlos Salazar García

    2012-09-01

    Full Text Available We report here on the results of carbon and nitrogen stable isotope analysis on bone collagen of humans from the Punic site of Can Marines (V-IVth BC from the island of Ibiza (Spain. To date, there are few isotopic studies for this period from the Mediterranean. This article reports new isotopic data from a Western Mediterranean Punic rural settlement. The results show a terrestrial based diet with no isotopic evidence of marine or freshwater protein input, and suggest the presence of C4 resources in it.

  10. Effects of Time of Initial Exposure to MSV Sarcoma on Bone Induction by Dentine Matrix Implants and on Orthotopic Femora

    Directory of Open Access Journals (Sweden)

    Aniela Brodzikowska

    2010-09-01

    Full Text Available HCl-demineralized murine lower incisors were implanted intramuscularly into syngeneic BALB/c mice to induce heterotopic osteogenesis. Implants were exposed at the early, preosteogenic stage (4, or at the later, osteogenic stage (12 to the Moloney sarcoma virus (MSV, which within 3–4 days results in a sarcoma. The yield of bone induction was determined by weight of dry bone mass following NaOH hydrolysis of soft tissues. To verify the effect of this sarcoma on orthotopic local femoral bone, the dry mass of the tumor-exposed femora was measured and compared with the weight of MSV-unexposed contralateral controls. MSV-sarcoma or cells involved with their spontaneous rejection have a stimulatory effect on the periosteal membrane of the tumor-adjacent femoral bones, increasing their dry mass on average by 18%. No stimulatory effect on heterotopic bone induction was observed when the MSV sarcoma grew during the early, preosteogenic stage (4 onward, but when the tooth matrix had been exposed to such tumor at the already bone-forming stage, (12 onward, the yield of bone induction was enhanced. Thus, it is postulated that lesions induced by MSV during the early, preosteogenic stage inhibit recruitment of osteoprogenitor cells or degrade Bone Morphogenetic Proteins (BMPs released by matrix resorbing inflammatory cells, whereas when acting on already existing bone they have a stimulatory effect.

  11. Real-time-guided bone regeneration around standardized critical size calvarial defects using bone marrow-derived mesenchymal stem cells and collagen membrane with and without using tricalcium phosphate: an in vivo microcomputed tomographic and histologic experiment in rats

    Institute of Scientific and Technical Information of China (English)

    Khalid Al-Hezaimi; Sundar Ramalingam; Mansour Al-Askar; Aws S ArRejaie; Nasser Nooh; Fawad Jawad; Abdullah Aldahmash; Muhammad Atteya; Cun-Yu Wang

    2016-01-01

    The aimof the present real time in vivo micro-computed tomography (mCT) and histologic experiment was to assess the efficacy of guided bone regeneration (GBR) around standardized calvarial critical size defects (CSD) using bone marrow-derived mesenchymal stem cells (BMSCs), and collagen membrane (CM) with and without tricalcium phosphate (TCP) graft material. In the calvaria of nine female Sprague-Dawley rats, full-thickness CSD (diameter 4.6 mm) were created under general anesthesia. Treatment-wise, rats were divided into three groups. In group 1, CSD was covered with a resorbable CM; in group 2, BMSCs were filled in CSD and covered with CM; and in group 3, TCP soaked in BMSCs was placed in CSD and covered with CM. All defects were closed using resorbable sutures. Bone volume and bone mineral density of newly formed bone (NFB) and remaining TCP particles and rate of new bone formation was determined at baseline, 2, 4, 6, and 10 weeks using in vivo mCT. At the 10th week, the rats were killed and calvarial segments were assessed histologically. The results showed that the hardness ofNFBwas similar to that of the native bone in groups 1 and 2 as compared to theNFB in group 3. Likewise, values for the modulus of elasticity were also significantly higher in group 3 compared to groups 1 and 2. This suggests that TCP when used in combination with BMSCs and without CM was unable to form bone of significant strength that could possibly provide mechanical “lock” between the natural bone and NFB. The use of BMSCs as adjuncts to conventional GBR initiated new bone formation as early as 2 weeks of treatment compared to when GBR is attempted without adjunct BMSC therapy.

  12. Leishmania amazonensis promastigotes in 3D Collagen I culture: an in vitro physiological environment for the study of extracellular matrix and host cell interactions

    Directory of Open Access Journals (Sweden)

    Debora B. Petropolis

    2014-04-01

    Full Text Available Leishmania amazonensis is the causative agent of American cutaneous leishmaniasis, an important neglected tropical disease. Once Leishmania amazonensis is inoculated into the human host, promastigotes are exposed to the extracellular matrix (ECM of the dermis. However, little is known about the interaction between the ECM and Leishmania promastigotes. In this study we established L. amazonensis promastigote culture in a three-dimensional (3D environment mainly composed of Collagen I (COL I. This 3D culture recreates in vitro some aspects of the human host infection site, enabling the study of the interaction mechanisms of L. amazonensis with the host ECM. Promastigotes exhibited “freeze and run” migration in the 3D COL I matrix, which is completely different from the conventional in vitro swimming mode of migration. Moreover, L. amazonensis promastigotes were able to invade, migrate inside, and remodel the 3D COL I matrix. Promastigote trans-matrix invasion and the freeze and run migration mode were also observed when macrophages were present in the matrix. At least two classes of proteases, metallo- and cysteine proteases, are involved in the 3D COL I matrix degradation caused by Leishmania. Treatment with a mixture of protease inhibitors significantly reduced promastigote invasion and migration through this matrix. Together our results demonstrate that L. amazonensis promastigotes release proteases and actively remodel their 3D environment, facilitating their migration. This raises the possibility that promastigotes actively interact with their 3D environment during the search for their cellular “home”—macrophages. Supporting this hypothesis, promastigotes migrated faster than macrophages in a novel 3D co-culture model.

  13. Influence of mineral phase in mineralization of a biocomposite containing chitosan, demineralized bone matrix and bone ash—in vitro study

    Indian Academy of Sciences (India)

    Krithiga Gunasekaran; Santhosh Kumar Baskar; Divya Sapphire Mohan; Thotapalli P Sastry

    2014-05-01

    A resorbable composite which acts as a active barrier in guided bone regeneration was fabricated using chitosan, demineralized bone matrix and bone ash. Its potential to form bone like apatite in simulated body fluid was assessed in this study. The mechanical strength of these composites was correlated with bone ash ratios and composites with better tensile strength were studied for their acellular bioactivity by incubating in simulated body fluid for 21 days. Composites without bone ash did not show acellular bioactivity which was confirmed by thermogravimetric analysis. In case of biocomposites with bone ash, there was an increase in residual weight indicating the mineralization of the composite. The composite containing bone ash has shown the peaks related to phosphate vibrations in its Fourier-transform infrared spectrum. Scanning micrographs revealed formation of apatite like crystals on its surface. Ca/P ratio was found to be 1.7 which is nearer to that of natural bone. Thus, prepared composites can be used as resorbable biocomposite in maxillofacial and oral defects.

  14. Ridge preservation with acellular dermal matrix and anorganic bone matrix cell-binding peptide P-15 after tooth extraction in humans. A histologic and morphometric study

    Directory of Open Access Journals (Sweden)

    Arthur B. Novaes Jr

    2012-06-01

    Full Text Available Aim: The aim of this study was to analyze by histomorphometric parameters the use of acellular dermal matrix (ADM with or without anorganic bovine bone matrix (ABM / synthetic cell-binding peptide P-15 in the formation of bone in human alveoli. Materials and methods: Eighteen patients in need of extraction of maxillary anterior teeth were selected and randomly assigned to the test group (ADM plus ABM/P-15 or the control group (ADM only. Histomorphometric measurements and histological analysis were recorded about 6 months after ridge preservation procedures in ten patients. The amount of newly formed bone, the most recently formed bone, fibrous tissue plus marrow spaces and remaining graft particles were measured and analyzed. Results: At 6 months, the new bone area parameter and the percentage of fibrous tissue plus marrow space areas showed higher values to the control group, and statistically significant differences when compared with the test group (p=0.03. Conclusion: The ADM acted as a membrane. The association of ABM/P-15 with ADM resulted in new bone formation within the alveoli, but the results were not considered relevant when used in this indication.

  15. Urinary excretion of type I collagen cross-linked N-telopeptides, bone mass and related lifestyle in middle-aged women.

    Directory of Open Access Journals (Sweden)

    Masatomi C

    1999-06-01

    Full Text Available The relationship between past and present lifestyle and urinary excretion of type I collagen cross-linked N-telopeptides (NTx was studied in 61 Japanese females aged 34-59, with a view toward using NTx excretion rates as a predictor of future osteoporosis. Bone mineral density (BMD of the lumbar spine, the speed of sound (SOS and broadband ultrasound attenuation (BUA of the os calcis, urinary NTx, serum osteocalcin (BGP and bone-specific alkaline phosphatase (BAP were measured. Stiffness index (stiffness was calculated from SOS and BUA. The subjects were asked whether they took regular exercise in their childhood and teen years (in elementary, junior-high, senior-high school and college, the past (20-40 years of age and present adulthood. Regular calcium intake, smoking habits, alcohol and other beverage consumption and milk consumption were also covered in the questionnaire. The mean NTx values of premenopausal and postmenopausal group were 22.2 and 56.0 nM bone collagen equivalents (BCE/mM urinary creatinine (Cr, respectively. The group which did not exercise regularly between the ages of 20 and 40 had a higher mean NTx value (40.9 nMBCE/mMCr than the group which did exercise regularly (22.7 nMBCE/mMCr. In multiple regression analyses, age, stiffness and exercise in past adulthood could explain 43.5% of the NTx variance. For prevention of bone metabolic increases around menopause, habitual exercise in early adulthood seems to be effective.

  16. Enhanced physicochemical properties of collagen by using EDC/NHS-crosslinking

    Indian Academy of Sciences (India)

    Chunrong Yang

    2012-10-01

    Collagen-based scaffolds are appealing products for the repair of cartilage defects using tissue engineering strategies. The present study investigated the collagen scaffolds with and without 1-ethyl-3-(3-dimethyl aminopropyl) carbodiimide (EDC)/-hydroxysuccinimide (NHS)-crosslinking. Crosslinking density, matrix morphology, swelling ratio shrinkage temperature and resistance against collagenase digestion were determined to evaluate the physicochemical properties of the collagen matrices with and without crosslinking. The results conformed that the porous structure of collagen was largely preserved and adjusted by crosslinking treatment. Furthermore, crosslinked collagen samples showed significantly reduced swelling ratio and increased resistance against thermal treatment and enzymatic degradation compared to non-crosslinked samples. An in vitro evaluation of MC3T3-E1 cells seeded onto the crosslinked and non-crosslinked collagen matrix indicated that crosslinked collagen was nontoxic and improved cell proliferation. Through this work, it was shown that an osteoconductive collagen matrix with optimized properties used as bioactive and bioresorbable scaffolds in bone tissue engineering could be fabricated through the EDC/NHS-crosslinking method.

  17. Next generation bone tissue engineering: non-viral miR-133a inhibition using collagen-nanohydroxyapatite scaffolds rapidly enhances osteogenesis

    Science.gov (United States)

    Mencía Castaño, Irene; Curtin, Caroline M.; Duffy, Garry P.; O’Brien, Fergal J.

    2016-06-01

    Bone grafts are the second most transplanted materials worldwide at a global cost to healthcare systems valued over $30 billion every year. The influence of microRNAs in the regenerative capacity of stem cells offers vast therapeutic potential towards bone grafting; however their efficient delivery to the target site remains a major challenge. This study describes how the functionalisation of porous collagen-nanohydroxyapatite (nHA) scaffolds with miR-133a inhibiting complexes, delivered using non-viral nHA particles, enhanced human mesenchymal stem cell-mediated osteogenesis through the novel focus on a key activator of osteogenesis, Runx2. This study showed enhanced Runx2 and osteocalcin expression, as well as increased alkaline phosphatase activity and calcium deposition, thus demonstrating a further enhanced therapeutic potential of a biomaterial previously optimised for bone repair applications. The promising features of this platform offer potential for a myriad of applications beyond bone repair and tissue engineering, thus presenting a new paradigm for microRNA-based therapeutics.

  18. Next generation bone tissue engineering: non-viral miR-133a inhibition using collagen-nanohydroxyapatite scaffolds rapidly enhances osteogenesis

    Science.gov (United States)

    Mencía Castaño, Irene; Curtin, Caroline M.; Duffy, Garry P.; O’Brien, Fergal J.

    2016-01-01

    Bone grafts are the second most transplanted materials worldwide at a global cost to healthcare systems valued over $30 billion every year. The influence of microRNAs in the regenerative capacity of stem cells offers vast therapeutic potential towards bone grafting; however their efficient delivery to the target site remains a major challenge. This study describes how the functionalisation of porous collagen-nanohydroxyapatite (nHA) scaffolds with miR-133a inhibiting complexes, delivered using non-viral nHA particles, enhanced human mesenchymal stem cell-mediated osteogenesis through the novel focus on a key activator of osteogenesis, Runx2. This study showed enhanced Runx2 and osteocalcin expression, as well as increased alkaline phosphatase activity and calcium deposition, thus demonstrating a further enhanced therapeutic potential of a biomaterial previously optimised for bone repair applications. The promising features of this platform offer potential for a myriad of applications beyond bone repair and tissue engineering, thus presenting a new paradigm for microRNA-based therapeutics. PMID:27297802

  19. Hydroxyapatite reinforced collagen scaffolds with improved architecture and mechanical properties.

    Science.gov (United States)

    Kane, Robert J; Weiss-Bilka, Holly E; Meagher, Matthew J; Liu, Yongxing; Gargac, Joshua A; Niebur, Glen L; Wagner, Diane R; Roeder, Ryan K

    2015-04-01

    Hydroxyapatite (HA) reinforced collagen scaffolds have shown promise for synthetic bone graft substitutes and tissue engineering scaffolds. Freeze-dried HA-collagen scaffolds are readily fabricated and have exhibited osteogenicity in vivo, but are limited by an inherent scaffold architecture that results in a relatively small pore size and weak mechanical properties. In order to overcome these limitations, HA-collagen scaffolds were prepared by compression molding HA reinforcements and paraffin microspheres within a suspension of concentrated collagen fibrils (∼ 180 mg/mL), cross-linking the collagen matrix, and leaching the paraffin porogen. HA-collagen scaffolds exhibited an architecture with high porosity (85-90%), interconnected pores ∼ 300-400 μm in size, and struts ∼ 3-100 μm in thickness containing 0-80 vol% HA whisker or powder reinforcements. HA reinforcement enabled a compressive modulus of up to ∼ 1 MPa, which was an order of magnitude greater than unreinforced collagen scaffolds. The compressive modulus was also at least one order of magnitude greater than comparable freeze-dried HA-collagen scaffolds and two orders of magnitude greater than absorbable collagen sponges used clinically. Moreover, scaffolds reinforced with up to 60 vol% HA exhibited fully recoverable elastic deformation upon loading to 50% compressive strain for at least 100,000 cycles. Thus, the scaffold mechanical properties were well-suited for surgical handling, fixation, and bearing osteogenic loads during bone regeneration. The scaffold architecture, permeability, and composition were shown to be conducive to the infiltration and differentiation of adipose-derive stromal cells in vitro. Acellular scaffolds were demonstrated to induce angiogenesis and osteogenesis after subcutaneous ectopic implantation by recruiting endogenous cell populations, suggesting that the scaffolds were osteoinductive.

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

    Institute of Scientific and Technical Information of China (English)

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

    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 re-spects, 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 poly-lactic 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 ifbers, and a completely degraded and resorbed conduit, in the polylac-tic 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 ben-eifcial for the regeneration and functional reconstruction of sciatic nerve. Better regeneration was found with the

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

    Directory of Open Access Journals (Sweden)

    1.\tSjoerd P.F.T. Nota

    2014-10-01

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

  2. Regional alterations of type I collagen in rat tibia induced by skeletal unloading

    Science.gov (United States)

    Shiiba, Masashi; Arnaud, Sara B.; Tanzawa, Hideki; Kitamura, Eiji; Yamauchi, Mitsuo

    2002-01-01

    Skeletal unloading induces loss of mineral density in weight-bearing bones that leads to inferior bone mechanical strength. This appears to be caused by a failure of bone formation; however, its mechanisms still are not well understood. The objective of this study was to characterize collagen, the predominant matrix protein in bone, in various regions of tibia of rats that were subjected to skeletal unloading by 4 weeks tail suspension. Sixteen male Sprague-Dawley rats (4 months old) were divided into tail suspension and ambulatory controls (eight rats each). After the tail suspension, tibias from each animal were collected and divided into five regions and collagen was analyzed. The collagen cross-linking and the extent of lysine (Lys) hydroxylation in unloaded bones were significantly altered in proximal epiphysis, diaphysis, and, in particular, proximal metaphysis but not in distal regions. The pool of immature/nonmineralized collagen measured by its extractability with a chaotropic solvent was significantly increased in proximal metaphysis. These results suggest that skeletal unloading induced an accumulation of post-translationally altered nonmineralized collagen and that these changes are bone region specific. These alterations might be caused by impaired osteoblastic function/differentiation resulting in a mineralization defect.

  3. Collagenous sprue

    DEFF Research Database (Denmark)

    Soendergaard, Christoffer; Riis, Lene Buhl; Nielsen, Ole Haagen

    2014-01-01

    Collagenous sprue is a rare clinicopathological condition of the small bowel. It is characterised by abnormal subepithelial collagen deposition and is typically associated with malabsorption, diarrhoea and weight loss. The clinical features of collagenous sprue often resemble those of coeliac...

  4. An Investigation of Coral Based Bioactive Composite Bone in a Critical-sized Cranial Defects

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    1 IntroductionNatural coral is a porous three-dimensional biocompatible material with osteo-conductivity~([1]). Recombinant human bone morphogenetic protein-2 (rhBMP-2) is a member of TGF-β family possessing strong osteoinductive properties~([2]). Collagen has been demonstrated efficacy in sustained releasing growth factor due to gradually absorption of collagen matrix~([3]). And bone marrow derived mesenchymal stem cells (BMSCs) have been chosen as seed cells owing to the capacity of differentiating into o...

  5. Bone marrow derived cell-seeded extracellular matrix: A novel biomaterial in the field of wound management

    OpenAIRE

    V. Remya; Naveen Kumar; Sharma, A. K.; Mathew, Dayamon D.; Mamta Negi; S.K. Maiti; Sameer Shrivastava; S. Sonal; KURADE, N.P.

    2014-01-01

    Aim: Extensive or irreversible damage to the skin often requires additional skin substitutes for reconstruction. Biomaterials have become critical components in the development of effective new medical therapies for wound care. Materials and Methods: In the present study, a cell matrix construct (bone marrow-derived cells (BMdc) seeded extracellular matrix [ECM]) was used as a biological substitute for the repair of full-thickness skin wound. ECM was developed by decellularizing fish swim ...

  6. Collagen biosynthesis.

    OpenAIRE

    Last, J A; Reiser, K M

    1984-01-01

    Collagen is the major structural protein of the lung. At least five genetically distinct collagen types have been identified in lung tissue. However, the precise role of collagen in nonrespiratory lung function is not well understood, in part because of the difficulties inherent in studying lung collagen, regardless of the type of assay used. A major problem is the insolubility of lung collagen; generally less than 20% of total lung collagen can be solubilized as intact chains, even with hars...

  7. The Great Irish Famine: Identifying Starvation in the Tissues of Victims Using Stable Isotope Analysis of Bone and Incremental Dentine Collagen

    Science.gov (United States)

    Montgomery, Janet

    2016-01-01

    The major components of human diet both past and present may be estimated by measuring the carbon and nitrogen isotope ratios (δ13C and δ15N) of the collagenous proteins in bone and tooth dentine. However, the results from these two tissues differ substantially: bone collagen records a multi-year average whilst primary dentine records and retains time-bound isotope ratios deriving from the period of tooth development. Recent studies harnessing a sub-annual temporal sampling resolution have shed new light on the individual dietary histories of our ancestors by identifying unexpected radical short-term dietary changes, the duration of breastfeeding and migration where dietary change occurs, and by raising questions regarding factors other than diet that may impact on δ13C and δ15N values. Here we show that the dentine δ13C and δ15N profiles of workhouse inmates dating from the Great Irish Famine of the 19th century not only record the expected dietary change from C3 potatoes to C4 maize, but when used together they also document prolonged nutritional and other physiological stress resulting from insufficient sustenance. In the adults, the influence of the maize-based diet is seen in the δ13C difference between dentine (formed in childhood) and rib (representing an average from the last few years of life). The demonstrated effects of stress on the δ13C and δ15N values will have an impact on the interpretations of diet in past populations even in slow-turnover tissues such as compact bone. This technique also has applicability in the investigation of modern children subject to nutritional distress where hair and nails are unavailable or do not record an adequate period of time. PMID:27508412

  8. The Effect of Gradations in Mineral Content, Matrix Alignment, and Applied Strain on Human Mesenchymal Stem Cell Morphology within Collagen Biomaterials.

    Science.gov (United States)

    Mozdzen, Laura C; Thorpe, Stephen D; Screen, Hazel R C; Harley, Brendan A C

    2016-07-01

    The tendon-bone junction is a unique, mechanically dynamic, structurally graded anatomical zone, which transmits tensile loads between tendon and bone. Current surgical repair techniques rely on mechanical fixation and can result in high re-failure rates. A new class of collagen biomaterial that contains discrete mineralized and structurally aligned regions linked by a continuous interface to mimic the graded osteotendinous insertion has been recently described. Here the combined influence of graded biomaterial environment and increasing levels of applied strain (0%-20%) on mesenchymal stem cell (MSC) orientation and alignment have been reported. In osteotendinous scaffolds, which contain opposing gradients of mineral content and structural alignment characteristic of the native osteotendinous interface, MSC nuclear, and actin alignment is initially dictated by the local pore architecture, while applied tensile strain enhances cell alignment in the direction of strain. Comparatively, in layered scaffolds that do not contain any structural alignment cues, MSCs are randomly oriented in the unstrained condition, then become oriented in a direction perpendicular to applied strain. These findings provide an initial understanding of how scaffold architecture can provide significant, potentially competitive, feedback influencing MSC orientation under applied strain, and form the basis for future tissue engineering efforts to regenerate the osteotendinous enthesis.

  9. The Effect of Gradations in Mineral Content, Matrix Alignment, and Applied Strain on Human Mesenchymal Stem Cell Morphology within Collagen Biomaterials.

    Science.gov (United States)

    Mozdzen, Laura C; Thorpe, Stephen D; Screen, Hazel R C; Harley, Brendan A C

    2016-07-01

    The tendon-bone junction is a unique, mechanically dynamic, structurally graded anatomical zone, which transmits tensile loads between tendon and bone. Current surgical repair techniques rely on mechanical fixation and can result in high re-failure rates. A new class of collagen biomaterial that contains discrete mineralized and structurally aligned regions linked by a continuous interface to mimic the graded osteotendinous insertion has been recently described. Here the combined influence of graded biomaterial environment and increasing levels of applied strain (0%-20%) on mesenchymal stem cell (MSC) orientation and alignment have been reported. In osteotendinous scaffolds, which contain opposing gradients of mineral content and structural alignment characteristic of the native osteotendinous interface, MSC nuclear, and actin alignment is initially dictated by the local pore architecture, while applied tensile strain enhances cell alignment in the direction of strain. Comparatively, in layered scaffolds that do not contain any structural alignment cues, MSCs are randomly oriented in the unstrained condition, then become oriented in a direction perpendicular to applied strain. These findings provide an initial understanding of how scaffold architecture can provide significant, potentially competitive, feedback influencing MSC orientation under applied strain, and form the basis for future tissue engineering efforts to regenerate the osteotendinous enthesis. PMID:27245787

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

    Science.gov (United States)

    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.

  11. Collagen and gelatin.

    Science.gov (United States)

    Liu, Dasong; Nikoo, Mehdi; Boran, Gökhan; Zhou, Peng; Regenstein, Joe M

    2015-01-01

    Collagen and gelatin have been widely used in the food, pharmaceutical, and cosmetic industries due to their excellent biocompatibility, easy biodegradability, and weak antigenicity. Fish collagen and gelatin are of renewed interest, owing to the safety and religious concerns of their mammalian counterparts. The structure of collagen has been studied using various modern technologies, and interpretation of the raw data should be done with caution. The structure of collagen may vary with sources and seasons, which may affect its applications and optimal extraction conditions. Numerous studies have investigated the bioactivities and biological effects of collagen, gelatin, and their hydrolysis peptides, using both in vitro and in vivo assay models. In addition to their established nutritional value as a protein source, collagen and collagen-derived products may exert various potential biological activities on cells in the extracellular matrix through the corresponding food-derived peptides after ingestion, and this might justify their applications in dietary supplements and pharmaceutical preparations. Moreover, an increasing number of novel applications have been found for collagen and gelatin. Therefore, this review covers the current understanding of the structure, bioactivities, and biological effects of collagen, gelatin, and gelatin hydrolysates as well as their most recent applications. PMID:25884286

  12. Bone Markers

    Science.gov (United States)

    ... bone turnover: C-telopeptide (C-terminal telopeptide of type 1 collagen (CTx)) – a marker for bone resorption. It is ... resorption include: N-telopeptide (N-terminal telopeptide of type 1 collagen (NTx)) – a peptide fragment from the amino terminal ...

  13. Restoration of a Critical Mandibular Bone Defect Using Human Alveolar Bone-Derived Stem Cells and Porous Nano-HA/Collagen/PLA Scaffold.

    Science.gov (United States)

    Wang, Xing; Xing, Helin; Zhang, Guilan; Wu, Xia; Zou, Xuan; Feng, Lin; Wang, Dongsheng; Li, Meng; Zhao, Jing; Du, Jianwei; Lv, Yan; E, Lingling; Liu, Hongchen

    2016-01-01

    Periodontal bone defects occur in a wide variety of clinical situations. Adult stem cell- and biomaterial-based bone tissue regeneration are a promising alternative to natural bone grafts. Recent evidence has demonstrated that two populations of adult bone marrow mesenchymal stromal cells (BMSCs) can be distinguished based on their embryonic origins. These BMSCs are not interchangeable, as bones preferentially heal using cells that share the same embryonic origin. However, the feasibility of tissue engineering using human craniofacial BMSCs was unclear. The goal of this study was to explore human craniofacial BMSC-based therapy for the treatment of localized mandibular defects using a standardized, minimally invasive procedure. The BMSCs' identity was confirmed. Scanning electron microscopy, a cell proliferation assay, and supernatant detection indicated that the nHAC/PLA provided a suitable environment for aBMSCs. Real-time PCR and electrochemiluminescence immunoassays demonstrated that osteogenic markers were upregulated by osteogenic preinduction. Moreover, in a rabbit critical-size mandibular bone defect model, total bone formation in the nHAC/PLA + aBMSCs group was significantly higher than in the nHAC/PLA group but significantly lower than in the nHAC/PLA + preinduced aBMSCs. These findings demonstrate that this engineered bone is a valid alternative for the correction of mandibular bone defects.

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

    Science.gov (United States)

    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

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

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

    2010-06-01

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

  17. Biological Assessment of a Calcium Silicate Incorporated Hydroxyapatite-Gelatin Nanocomposite: A Comparison to Decellularized Bone Matrix

    Directory of Open Access Journals (Sweden)

    Dong Joon Lee

    2014-01-01

    Full Text Available 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.

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

    Science.gov (United States)

    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

  19. The comparative effectiveness of demineralized bone matrix, beta-tricalcium phosphate, and bovine-derived anorganic bone matrix on inflammation and bone formation using a paired calvarial defect model in rats

    Directory of Open Access Journals (Sweden)

    Khoshzaban A

    2011-09-01

    Full Text Available Ahad Khoshzaban1,2,3, Shahram Mehrzad1, Vida Tavakoli2, Saeed Heidari Keshel2, Gholam Reza Behrouzi2, Maryam Bashtar2 1Iranian Tissue Bank Research and Preparation Center, Imam Khomeini Hospital Complex, 2Stem Cells Preparation Unit, Eye Research Center, Farabi Hospital, Tehran University of Medical Science, 3Dental Bio Material Department, Tehran University of Medical Science, Faculty of Dentistry, Tehran, Iran Background: In this study, the effectiveness of Iranian Tissue Bank–produced demineralized bone matrix (ITB-DBM, beta-tricalcium phosphate (ßTCP, and Bio-Oss® (Geistlich Pharma AG, Wolhusen, Switzerland were evaluated and compared with double controls. The main goal was to measure the amount of new bone formation in the center of defects created in rat calvaria. Another goal was to compare the controls and evaluate the effects of each treatment material on their adjacent untreated (control defects. Methods: In this study, 40 male Wistar rats were selected and divided into four groups, In each group, there were ten rats with two defects in their calvarias; one of them is considered as control and the other one was treated with ITB-DBM (group 1, BIO-OSS (group2, and ßTCP (group 3, respectively. But in group 4, both defects were considered as control. The amount of inflammation and new bone formation were evaluated at 4 and 10 weeks. In the first group, one defect was filled with ITB-DBM; in the second group, one defect was filled with Bio-Oss; in the third group, one defect was filled with ßTCP; and in the fourth group, both defects were left unfilled. Zeiss microscope (Carl Zeiss AG, Oberkochen, Germany and Image Tool® (version 3.0; University of Texas Health Science Center at San Antonio, San Antonio, TX software were used for evaluation. SPSS Statistics (IBM Corp, Somers, NY was used for statistical analysis. Results: Maximum bone formation at 4 and 10 weeks were observed in the ITB-DBM group (46.960% ± 4.366%, 94.970% ± 0

  20. Collagenous Gastritis

    OpenAIRE

    Hugh J Freeman; Piercy, James R.A.; Raine, Robert J.

    1989-01-01

    A 54-year-old woman presented with nausea, vomiting and weight loss associated with impaired gastric emptying necessitating institution of parenteral nutrition. Subsequent studies revealed an unusual gastric mucosa! inflammatory process characterized by unique subepithelial collagenous deposits. Collagenous gastritis appears to be a distinct, possibly immune-mediated, chronic disorder, pathologically reminiscent of collagenous sprue and collagenous colitis.

  1. 'Universal' microstructural patterns in cortical and trabecular, extracellular and extravascular bone materials: micromechanics-based prediction of anisotropic elasticity.

    Science.gov (United States)

    Fritsch, Andreas; Hellmich, Christian

    2007-02-21

    Bone materials are characterized by an astonishing variability and diversity. Still, because of 'architectural constraints' due to once chosen material constituents and their physical interaction, the fundamental hierarchical organization or basic building plans of bone materials remain largely unchanged during biological evolution. Such universal patterns of microstructural organization govern the mechanical interaction of the elementary components of bone (hydroxyapatite, collagen, water; with directly measurable tissue-independent elastic properties), which are here quantified through a multiscale homogenization scheme delivering effective elastic properties of bone materials: at a scale of 10nm, long cylindrical collagen molecules, attached to each other at their ends by approximately 1.5nm long crosslinks and hosting intermolecular water inbetween, form a contiguous matrix called wet collagen. At a scale of several hundred nanometers, wet collagen and mineral crystal agglomerations interpenetrate each other, forming the mineralized fibril. At a scale of 5-10microm, the extracellular solid bone matrix is represented as collagen fibril inclusions embedded in a foam of largely disordered (extrafibrillar) mineral crystals. At a scale above the ultrastructure, where lacunae are embedded in extracellular bone matrix, the extravascular bone material is observed. Model estimates predicted from tissue-specific composition data gained from a multitude of chemical and physical tests agree remarkably well with corresponding acoustic stiffness experiments across a variety of cortical and trabecular, extracellular and extravascular materials. Besides from reconciling the well-documented, seemingly opposed concepts of 'mineral-reinforced collagen matrix' and 'collagen-reinforced mineral matrix' for bone ultrastructure, this approach opens new possibilities in the exploitation of computer tomographic data for nano-to-macro mechanics of bone organs. PMID:17074362

  2. Real-Time Assessment of Guided Bone Regeneration in Standardized Calvarial Defects Using a Combination of Bone Graft and Platelet-Derived Growth Factor With and Without Collagen Membrane: An In Vivo Microcomputed Tomographic and Histologic Experiment in Rats.

    Science.gov (United States)

    Alrasheed, Abdulaziz; Al-Ahmari, Fatemah; Ramalingam, Sundar; Nooh, Nasser; Wang, Cun-Yu; Al-Hezaimi, Khalid

    2016-01-01

    The aim of the present in vivo microcomputed tomography (μCT) and histologic experiment was to assess the efficacy of guided bone regeneration (GBR) around standardized calvarial defects using recombinant human platelet-derived growth factor (rhPDGF) with and without resorbable collagen membrane (RCM). A total of 50 female Wistar albino rats with a mean age of 7.5 months and mean weight of 275 g were used. The calvarium was exposed following midsagittal scalp incision and flap reflection. A full-thickness standardized calvarial defect (4.6 mm diameter) was created. Study animals were randomly divided into five groups based on biomaterials used for GBR within the defect: (1) no treatment (negative control), (2) bone graft alone (BG), (3) bone graft covered by RCM (BG + RCM), (4) bone graft soaked in rhPDGF (BG + rhPDGF), and (5) bone graft soaked in rhPDGF and covered with RCM (BG + rhPDGF + RCM). In vivo μCT for determination of newly formed bone volume (NFBV) and mineral density (NFBMD) and remnant bone particles volume (RBPV) and mineral density (RBPMD) was done at baseline and at 2, 4, 6, and 8 weeks postoperatively. Eight weeks following surgery, the animals were sacrificed and harvested calvarial specimens were subjected to histologic and biomechanical analysis. There was an increase in NFBV and NFBMD associated with a corresponding decrease in RBPV and RBPMD in all the study groups. Two-way analysis of variance revealed significant differences in the measured values within and between the groups across the timelines examined during the study period (P RCM, and BG + rhPDGF + RCM groups, the NFBMD was similar in all the groups except negative control. The greatest decreases in RBPV and RBPMD were observed in the BG + rhPDGF + RCM group in comparison to the other groups. Similarly, BG + rhPDGF + RCM groups had hardness and elastic modulus similar to that of natural bone. The in vivo μCT results were validated by the qualitative histologic findings. In real

  3. Remission of collagen-induced arthritis through combination therapy of microfracture and transplantation of thermogel-encapsulated bone marrow mesenchymal stem cells.

    Directory of Open Access Journals (Sweden)

    He Liu

    Full Text Available The persistent inflammation of rheumatoid arthritis (RA always leads to partial synovial hyperplasia and the destruction of articular cartilage. Bone marrow mesenchymal stem cells (BMMSCs have been proven to possess immunosuppressive effects, and widely explored in the treatment of autoimmune diseases. However, poor inhibitory effect on local inflammatory state and limited capacity of preventing destruction of articular cartilage by systemic BMMSCs transplantation were observed. Herein, toward the classical type II collagen-induced arthritis in rats, the combination treatment of microfracture and in situ transplantation of thermogel-encapsulated BMMSCs was verified to obviously down-regulate the ratio of CD4+ to CD8+ T lymphocytes in peripheral blood. In addition, it resulted in the decreased levels of inflammatory cytokines, such as interleukin-1β, tumor necrosis factor-α and anti-collagen type II antibody, in the serum. Simultaneously, the combination therapy also could inhibit the proliferation of antigen specific lymphocytes and local joint inflammatory condition, and prevent the articular cartilage damage. The results indicated that the treatment programs could effectively stimulate the endogenous and exogenous BMMSCs to exhibit the immunosuppression and cartilage protection capability. This study provided a new therapeutic strategy for autoimmune inflammatory diseases, such as RA.

  4. Unique micro- and nano-scale mineralization pattern of human osteogenesis imperfecta type VI bone.

    Science.gov (United States)

    Fratzl-Zelman, Nadja; Schmidt, Ingo; Roschger, Paul; Roschger, Andreas; Glorieux, Francis H; Klaushofer, Klaus; Wagermaier, Wolfgang; Rauch, Frank; Fratzl, Peter

    2015-04-01

    Osteogenesis imperfecta (OI) is a heterogeneous group of inheritable connective tissue disorders characterized by mutation in genes involved in collagen synthesis and leading to increased bone fragility, low bone mass, impaired bone material properties and abnormally high bone matrix mineralization. Recessive OI type VI is caused by mutation in SERPINF1 leading to a loss-of-function of pigment epithelium-derived factor (PEDF) a collagen-binding protein with potent antiangiogenic activity. Affected patients develop a severe OI phenotype with a striking histological characteristic, rare in other OI types, of an excess of osteoid tissue and prolonged mineralization lag time. To get insights into matrix mineralization, we evaluated biopsies from 9 affected children by quantitative and by high-resolution backscattered electron imaging and assessed bone mineralization density distribution. Thickness, shape and arrangement of mineral particles were measured in a subset of 4 patients by synchrotron small angle X-ray scattering. Typical calcium content in the bone matrix was found to be increased compared to controls, even exceeding values found previously in OI patients with collagen-gene mutations. A main characteristic however, is the coexistence of this highly mineralized bone matrix with seams showing abnormally low mineral content. Atypical collagen fibril organization was found in the perilacunar region of young osteocytes, suggesting a disturbance in the early steps of mineralization. These observations are consistent with the presence of a heterogeneous population of mineral particles with unusual size, shape and arrangement, especially in the region with lower mineral content. The majority of the particles in the highly mineralized bone areas were less disorganized, but smaller and more densely packed than in controls and in previously measured OI patients. These data suggest that the lack of PEDF impairs a proper osteoblast-osteocyte transition and consequently

  5. [Actin cytoskeleton organization and spreading of bone marrow stromal cells and cartilage cells during their combined and independent cultivation on different extracellular matrix proteins].

    Science.gov (United States)

    Sakhenberg, E I; Nikolaenko, N S; Pinaev, G P

    2014-01-01

    To clarify the mutual influence of bone marrow stromal cells (BMSCs) and cartilage cells we studied the organization of their actin cytoskeleton and cell spreading on different extracellular matrix proteins--laminin 2/4, collagen type I or fibronectin. It has been shown that the most pronounced difference in morphological characteristics of the cells such as their form, size and actin cytoskeleton organization occur in the case of interaction with fibronectin. So, after separate brief incubation of both cell types on fibronectin, the average area of BMSCs spreading was about 4 times greater than the area of the cartilage cell spreading. However, in the co-culture of these cells in a ratio of 1:1, the average jointed spreading area on fibronctin was nearly 1.5 times less than the theoretically calculated. To determine the nature of exposure of the cells to each other we have studied spreading of these cells in the media conditioned by another cell type. We have found that the area of BMSC's spreading in the medium conditioned by cartilage cells is markedly smaller than the area of spreading of the same cells in the control medium. These data suggest that the cartilage cells secrete factors that reduce BMSC's spreading.

  6. Allograft of microencapsulated ovarian cells affects bone collagen metabolism in ovariectomized mice%卵巢细胞微囊移植对去卵巢小鼠的骨胶原代谢的影响

    Institute of Scientific and Technical Information of China (English)

    郭晓霞; 周金玲; 许晴; 史小林

    2011-01-01

    BACKGROUND: Gonad hormones are essential for the maintenance of skeletal integrity. The in vitro cultured ovarian cells can secrete estradiol and progesterone. Alginic acid-polylysine-alginic acid microcapsule provides a barrier between the graft and the recipient, thus promoting the survival of heterotransplants.OBJECTIVE: To explore the survival and secretion functions of allografted microencapsulated ovarian cells in ovariectomized mice and their effect on bone collagen metabolism after ovariectomy (OVX).METHODS: Ovarian cells separated from female Kunming mice (6 weeks old) were cultured and microencapsulated with alginic acid-polylysine-alginic acid. A total of 24 female Kunming mice (8 weeks old) were randomly divided into three groups (n=8):normal group: OVX was not performed; OVX group: OVX was performed; transplantation group: microencapsulated ovarian cells were transplanted into abdominal cavity after OVX. Estradiol and/or progesterone levels of the medium of microencapsulated ovarian cells and mice serum were determined by radioimmunoassay. Ⅰ type collagen fibers in the bone matrix were showed by Van Gieson staining. The concentrations of hydroxyproline, Ca, and P were measured in the left femurs of mice.RESULTS AND CONCLUSION: The concentrations of estradiol and progesterone in the culture medium were not significantly different between the cultured ovarian cells and microencapsulated ovarian cells. The serum estradiol concentration at 90 days after transplantation had no significant difference compared with that of normal group, whereas the serum estradiol concentration of the OVX group was significantly lower than that of the normal group. In the transplantation group, the distribution of collagen fibers was similar to that of the normal group determined by Van Gieson staining. In comparison to the normal group, the OVX group had less, thinner trabecular matrix, and fewer collagen fibers, more free trabecular terminals, and a thinner uncalcified

  7. PHAGOCYTOSIS AND REMODELING OF COLLAGEN MATRICES

    OpenAIRE

    Abraham, Leah C.; Dice, J. Fred; Lee, Kyongbum; Kaplan, David L.

    2007-01-01

    The biodegradation of collagen and the deposition of new collagen-based extracellular matrices are of central importance in tissue remodeling and function. Similarly, for collagen-based biomaterials used in tissue engineering, the degradation of collagen scaffolds with accompanying cellular infiltration and generation of new extracellular matrix is critical for integration of in vitro grown tissues in vivo. In earlier studies we observed significant impact of collagen structure on primary lun...

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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

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

    Science.gov (United States)

    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

  11. A titanium surface with nano-ordered spikes and pores enhances human dermal fibroblastic extracellular matrix production and integration of collagen fibers.

    Science.gov (United States)

    Yamada, Masahiro; Kato, Eiji; Yamamoto, Akiko; Sakurai, Kaoru

    2016-02-02

    The acquisition of substantial dermal sealing determines the prognosis of percutaneous titanium-based medical devices or prostheses. A nano-topographic titanium surface with ordered nano-spikes and pores has been shown to induce periodontal-like connective tissue attachment and activate gingival fibroblastic functions. This in vitro study aimed to determine whether an alkali-heat (AH) treatment-created nano-topographic titanium surface could enhance human dermal fibroblastic functions and binding strength to the deposited collagen on the titanium surface. The surface topographies of commercially pure titanium machined discs exposed to two different AH treatments were evaluated. Human dermal fibroblastic cultures grown on the discs were evaluated in terms of cellular morphology, proliferation, extracellular matrix (ECM) and proinflammatory cytokine synthesis, and physicochemical binding strength of surface-deposited collagen. An isotropically-patterned, shaggy nano-topography with a sponge-like inner network and numerous well-organized, anisotropically-patterned fine nano-spikes and pores were observed on each nano-topographic surface type via scanning electron microscopy. In contrast to the typical spindle-shaped cells on the machined surfaces, the isotropically- and anisotropically-patterned nano-topographic titanium surfaces had small circular/angular cells containing contractile ring-like structures and elongated, multi-shaped cells with a developed cytoskeletal network and multiple filopodia and lamellipodia, respectively. These nano-topographic surfaces enhanced dermal-related ECM synthesis at both the protein and gene levels, without proinflammatory cytokine synthesis or reduced proliferative activity. Deposited collagen fibers were included in these surfaces and sufficiently bound to the nano-topographies to resist the physical, enzymatic and chemical detachment treatments, in contrast to machined surfaces. Well-organized, isotropically

  12. Collagen fibril architecture, domain organization, and triple-helical conformation govern its proteolysis.

    Science.gov (United States)

    Perumal, Shiamalee; Antipova, Olga; Orgel, Joseph P R O

    2008-02-26

    We describe the molecular structure of the collagen fibril and how it affects collagen proteolysis or "collagenolysis." The fibril-forming collagens are major components of all mammalian connective tissues, providing the structural and organizational framework for skin, blood vessels, bone, tendon, and other tissues. The triple helix of the collagen molecule is resistant to most proteinases, and the matrix metalloproteinases that do proteolyze collagen are affected by the architecture of collagen fibrils, which are notably more resistant to collagenolysis than lone collagen monomers. Until now, there has been no molecular explanation for this. Full or limited proteolysis of the collagen fibril is known to be a key process in normal growth, development, repair, and cell differentiation, and in cancerous tumor progression and heart disease. Peptide fragments generated by collagenolysis, and the conformation of exposed sites on the fibril as a result of limited proteolysis, regulate these processes and that of cellular attachment, but it is not known how or why. Using computational and molecular visualization methods, we found that the arrangement of collagen monomers in the fibril (its architecture) protects areas vulnerable to collagenolysis and strictly governs the process. This in turn affects the accessibility of a cell interaction site located near the cleavage region. Our observations suggest that the C-terminal telopeptide must be proteolyzed before collagenase can gain access to the cleavage site. Collagenase then binds to the substrate's "interaction domain," which facilitates the triple-helix unwinding/dissociation function of the enzyme before collagenolysis.

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

    Science.gov (United States)

    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

  14. Extracellular matrix adaptation of tendon and skeletal muscle to exercise

    DEFF Research Database (Denmark)

    Kjaer, Michael; Magnusson, Peter; Krogsgaard, Michael;

    2006-01-01

    The extracellular matrix (ECM) of connective tissues enables linking to other tissues, and plays a key role in force transmission and tissue structure maintenance in tendons, ligaments, bone and muscle. ECM turnover is influenced by physical activity, and both collagen synthesis and metalloprotea...

  15. Biological Safety of Fish (Tilapia Collagen

    Directory of Open Access Journals (Sweden)

    Kohei Yamamoto

    2014-01-01

    Full Text Available Marine collagen derived from fish scales, skin, and bone has been widely investigated for application as a scaffold and carrier due to its bioactive properties, including excellent biocompatibility, low antigenicity, and high biodegradability and cell growth potential. Fish type I collagen is an effective material as a biodegradable scaffold or spacer replicating the natural extracellular matrix, which serves to spatially organize cells, providing them with environmental signals and directing site-specific cellular regulation. This study was conducted to confirm the safety of fish (tilapia atelocollagen for use in clinical application. We performed in vitro and in vivo biological studies of medical materials to investigate the safety of fish collagen. The extract of fish collagen gel was examined to clarify its sterility. All present sterility tests concerning bacteria and viruses (including endotoxin yielded negative results, and all evaluations of cell toxicity, sensitization, chromosomal aberrations, intracutaneous reactions, acute systemic toxicity, pyrogenic reactions, and hemolysis were negative according to the criteria of the ISO and the http://dx.doi.org/10.13039/501100003478 Ministry of Health, Labour and Welfare. The present study demonstrated that atelocollagen prepared from tilapia is a promising biomaterial for use as a scaffold in regenerative medicine.

  16. Biological safety of fish (tilapia) collagen.

    Science.gov (United States)

    Yamamoto, Kohei; Igawa, Kazunari; Sugimoto, Kouji; Yoshizawa, Yuu; Yanagiguchi, Kajiro; Ikeda, Takeshi; Yamada, Shizuka; Hayashi, Yoshihiko

    2014-01-01

    Marine collagen derived from fish scales, skin, and bone has been widely investigated for application as a scaffold and carrier due to its bioactive properties, including excellent biocompatibility, low antigenicity, and high biodegradability and cell growth potential. Fish type I collagen is an effective material as a biodegradable scaffold or spacer replicating the natural extracellular matrix, which serves to spatially organize cells, providing them with environmental signals and directing site-specific cellular regulation. This study was conducted to confirm the safety of fish (tilapia) atelocollagen for use in clinical application. We performed in vitro and in vivo biological studies of medical materials to investigate the safety of fish collagen. The extract of fish collagen gel was examined to clarify its sterility. All present sterility tests concerning bacteria and viruses (including endotoxin) yielded negative results, and all evaluations of cell toxicity, sensitization, chromosomal aberrations, intracutaneous reactions, acute systemic toxicity, pyrogenic reactions, and hemolysis were negative according to the criteria of the ISO and the Ministry of Health, Labour and Welfare of Japan. The present study demonstrated that atelocollagen prepared from tilapia is a promising biomaterial for use as a scaffold in regenerative medicine. PMID:24809058

  17. Collagen and Collagen-derived Fragments Are Chemotactic for Tumor Cells

    OpenAIRE

    Mundy, Gregory R; Demartino, Sandra; Rowe, David W.

    1981-01-01

    Organs that are rich in collagen such as liver, lungs, and bone are frequently sites of tumor cell metastasis. In this study, we have found that cultured tumor cells of human and rat origin migrated unidirectionally in response to collagen in vitro. Synthetic di- and tri-peptides that contained amino acid sequences found frequently in the collagen helix caused similar effects. These results are consistent with the hypothesis that collagen or collagen fragments released during connective tissu...

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

    Science.gov (United States)

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

    2016-01-20

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

  19. 偏振光显微观察不同胶原纤维在骨折愈合过程中的动态变化%Examination of dynamic changes of different-type collagens in bone fracture healing with a polarized light microscopy

    Institute of Scientific and Technical Information of China (English)

    李章华; 廖文; 张玉富; 赵强; 王常勇

    2005-01-01

    BACKGROUND:Sirius red is a strong acid anionic dye. Being not-easyto-fade and specific, sirius red becomes the best dye for collagen staining.Collagen is a major component of extracellular matrix and has some specific physiological functions. Through synthesis and reconstruction of collagen, bone fracture repair will be accomplished.OBJECTIVE: Picric acid-Sirius red stained slides were observed under a polarized light microscopy for evaluation the dynamic changes in the ratio of different collagen types and their distributions in bone fracture healing.DESIGN: It was a controlled observation.SETTING: It was conducted in the Department of Orthopedics, Renmin Hospital, Wuhan University; Department of Traumatic Orthopaedics, Tianjin Hospital; Department of Traumatic Orthopaedics, Jishuitan Hospital,Medical Department, Peking University; Tissue Engineering Center of Institute of Basic Medical Sciences, Academy of Military Medical Sciences of Chinese PLAMATERIALS: It was conducted at Tissue Engineering Center of Institute of Basic Medical Sciences, Academy of Military Medical Sciences of Chinese PLA from March 2002 to September 2003. Three healthy adult Chinese sheep, male and in weight from 25 to 35 g, were selected.METHODS: All the animals were anesthesized and sterilized; a transverse osteotomy of the trunk of metatarsus was performed; and the end of fracture was fixed with a six-hole Medoff sliding plate. At the post-operative month 1, 3 and 6, samples were taken from bone fractures. After decalcification with EDTA, they were stained with Picric acid-sirius red, and the types and distribution of collagens were observed under a polarized light microscopy.MAIN OUTCOME MEASURES: Types and distributions of collagens in bone lesion in different period of bone healing were investigated.RESULTS: Three sheep used in this study entered the statistical analysis.①Morphological features of various collagens under a polarized light microscopy postoperatively: Type Ⅰ collagen

  20. 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.

    Science.gov (United States)

    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

  1. Collagenous gastroduodenitis.

    Science.gov (United States)

    Rustagi, Tarun; Rai, Mridula; Scholes, John V

    2011-10-01

    Collagenous gastroduodenitis is a rare histopathologic entity characterized by marked subepithelial collagen deposition with associated mucosal inflammatory infiltrate. Only 4 cases have been reported, of which 3 had associated collagenous colitis. Collagenous gastroduodenitis without colonic involvement is exceptionally rare with only 1 case reported so far in the literature. We present a case of a 68-year-old woman with dyspepsia and mild anemia, who was found to have nodular gastric and duodenal mucosa on endoscopic examination. Histopathology showed collagenous gastroduodenitis. To the best of our knowledge, this is the second (and first in English literature) reported case of isolated collagenous gastroduodenitis.

  2. Combined Effects of Mechanical Strain and Hydroxyapatite/Collagen Composite on Osteogenic Differentiation of Rat Bone Marrow Derived Mesenchymal Stem Cells

    Directory of Open Access Journals (Sweden)

    Yan Huang

    2013-01-01

    Full Text Available Mesenchymal stem cells (MSCs represent a promising source for bone repair and regeneration. Recent lines of evidence have shown that appropriate strain could regulate the osteogenic differentiation of MSCs. Our previous study demonstrated that hydroxyapatite/collagen (HA/Col composite also played an important role in the osteogenic differentiation of MSCs. The aim of this study is to investigate the effects of mechanical strain and HA/Col composite on the osteogenic differentiation of rat bone marrow derived MSCs (rBMSCs in vitro. rBMSCs were treated with cyclic strain generated by a self-designed stretching device with or without the presence of HA/Col composite. Osteogenic differentiation levels were evaluated using reverse transcription polymerase chain reaction (RT-PCR, alkaline phosphatase spectrophotometry, and western blotting. The results demonstrated that mechanical strain combined with HA/Col composite could obviously induce the differentiation of rBMSCs into osteoblasts, which had a better effect than only mechanical strain or HA/Col composite treatment. This provides a new avenue for mechanistic studies of stem cell differentiation and a novel approach to obtain more committed differentiated cells.

  3. Mechanical loading induced expression of bone morphogenetic protein-2,alkaline phosphatase activity,and collagen synthesis in osteoblastic MC3T3-E1 cells

    Institute of Scientific and Technical Information of China (English)

    LU Hong-fei; MAI Zhi-hui; XU Ye; WANG Wei; AI Hong

    2012-01-01

    Background Bone morphogenetic protein(BMP)-2,alkaline phosphatase(ALP),and collagen typeⅠ?are known to play a critical role in the process of bone remodeling.However,the relationship between mechanical strain and the expression of BMP-2,ALP,and COL-Ⅰ?in osteoblasts was still unknown.The purpose of this study was to investigate the effects of different magnitudes of mechanical strain on osteoblast morphology and on the expression of BMP-2,ALP,and COL-Ⅰ.Methods Osteoblast-like cells were flexed at four deformation rates(0,6%,12%,and 18% elongation).The expression of BMP-2 mRNA,ALP,and COL-Ⅰ?in osteoblast-like cells were determined by real-time quantitative reverse transcription polymerase chain reaction,respectively.The results were subjected to analysis of variance(ANOVA)using SPSS 13.0 statistical software.Results The cells changed to fusiform and grew in the direction of the applied strain after the mechanical strain was loaded.Expression level of the BMP-2,ALP,and COL-Ⅰ?increased magnitude-dependently with mechanical loading in the experimental groups,and the 12% elongation group had the highest expression(P<0.05).Conclusion Mechanical strain can induce morphological change and a magnitude-dependent increase in the expression of BMP-2,ALP,and COL-Ⅰ?mRNA in osteoblast-like cells,which might influence bone remodeling in orthodontic treatment.

  4. Sulfated hyaluronan improves bone regeneration of diabetic rats by binding sclerostin and enhancing osteoblast function.

    Science.gov (United States)

    Picke, Ann-Kristin; Salbach-Hirsch, Juliane; Hintze, Vera; Rother, Sandra; Rauner, Martina; Kascholke, Christian; Möller, Stephanie; Bernhardt, Ricardo; Rammelt, Stefan; Pisabarro, M Teresa; Ruiz-Gómez, Gloria; Schnabelrauch, Matthias; Schulz-Siegmund, Michaela; Hacker, Michael C; Scharnweber, Dieter; Hofbauer, Christine; Hofbauer, Lorenz C

    2016-07-01

    Bone fractures in patients with diabetes mellitus heal poorly and require innovative therapies to support bone regeneration. Here, we assessed whether sulfated hyaluronan included in collagen-based scaffold coatings can improve fracture healing in diabetic rats. Macroporous thermopolymerized lactide-based scaffolds were coated with collagen including non-sulfated or sulfated hyaluronan (HA/sHA3) and inserted into 3 mm femoral defects of non-diabetic and diabetic ZDF rats. After 12 weeks, scaffolds coated with collagen/HA or collagen/sHA3 accelerated bone defect regeneration in diabetic, but not in non-diabetic rats as compared to their non-coated controls. At the tissue level, collagen/sHA3 promoted bone mineralization and decreased the amount of non-mineralized bone matrix. Moreover, collagen/sHA3-coated scaffolds from diabetic rats bound more sclerostin in vivo than the respective controls. Binding assays confirmed a high binding affinity of sHA3 to sclerostin. In vitro, sHA3 induced BMP-2 and lowered the RANKL/OPG expression ratio, regardless of the glucose concentration in osteoblastic cells. Both sHA3 and high glucose concentrations decreased the differentiation of osteoclastic cells. In summary, scaffolds coated with collagen/sHA3 represent a potentially suitable biomaterial to improve bone defect regeneration in diabetic conditions. The underlying mechanism involves improved osteoblast function and binding sclerostin, a potent inhibitor of Wnt signaling and osteoblast function. PMID:27131598

  5. Proteomics reveals drastic increase of extracellular matrix proteins collagen and dermatopontin in the aged mdx diaphragm model of Duchenne muscular dystrophy.

    Science.gov (United States)

    Carberry, Steven; Zweyer, Margit; Swandulla, Dieter; Ohlendieck, Kay

    2012-08-01

    Duchenne muscular dystrophy is a lethal genetic disease of childhood caused by primary abnormalities in the gene coding for the membrane cytoskeletal protein dystrophin. The mdx mouse is an established animal model of various aspects of X-linked muscular dystrophy and is widely used for studying fundamental mechanisms of dystrophinopathy and testing novel therapeutic approaches to treat one of the most frequent gender-specific diseases in humans. In order to determine global changes in the muscle proteome with the progressive deterioration of mdx tissue with age, we have characterized diaphragm muscle from mdx mice at three ages (8-weeks, 12-months and 22-months) using mass spectrometry-based proteomics. Altered expression levels in diaphragm of 8-week vs. 22-month mice were shown to occur in 11 muscle-associated proteins. Aging in the mdx diaphragm seems to be associated with a drastic increase in the extracellular matrix proteins, collagen and dermatopontin, the molecular chaperone αB-crystallin, and the intermediate filament protein vimentin, suggesting increased accumulation of connective tissue, an enhanced cellular stress response and compensatory stabilization of the weakened membrane cytoskeleton. These proteomic findings establish the aged mdx diaphragm as an excellent model system for studying secondary effects of dystrophin deficiency in skeletal muscle tissue.

  6. Epidermal growth factor promotes a mesenchymal over an amoeboid motility of MDA-MB-231 cells embedded within a 3D collagen matrix

    Science.gov (United States)

    Geum, Dongil T.; Kim, Beum Jun; Chang, Audrey E.; Hall, Matthew S.; Wu, Mingming

    2016-01-01

    The receptor of epidermal growth factor (EGFR) critically regulates tumor cell invasion and is a potent therapeutic target for treatment of many types of cancers, including carcinomas and glioblastomas. It is known that EGF regulates cell motility when tumor cells are embedded within a 3D biomatrix. However, roles of EGF in modulating tumor cell motility phenotype are largely unknown. In this article, we report that EGF promotes a mesenchymal over an amoeboid motility phenotype using a malignant breast tumor cell line, MDA-MB-231, embedded within a 3D collagen matrix. Amoeboid cells are rounded in shape, while mesenchymal cells are elongated, and their migrations are governed by a distinctly different set of biomolecules. Using single cell tracking analysis, we also show that EGF promotes cell dissemination through a significant increase in cell persistence along with a moderate increase of speed. The increase of persistence is correlated with the increase of the percentage of the mesenchymal cells within the population. Our work reveals a novel role of microenvironmental cue, EGF, in modulating heterogeneity and plasticity of tumor cell motility phenotype. In addition, it suggests a potential visual cue for diagnosing invasive states of breast cancer cells. This work can be easily extended beyond breast cancer cells.

  7. Microspectroscopic evidence of cretaceous bone proteins.

    Directory of Open Access Journals (Sweden)

    Johan Lindgren

    Full Text Available Low concentrations of the structural protein collagen have recently been reported in dinosaur fossils based primarily on mass spectrometric analyses of whole bone extracts. However, direct spectroscopic characterization of isolated fibrous bone tissues, a crucial test of hypotheses of biomolecular preservation over deep time, has not been performed. Here, we demonstrate that endogenous proteinaceous molecules are retained in a humerus from a Late Cretaceous mosasaur (an extinct giant marine lizard. In situ immunofluorescence of demineralized bone extracts shows reactivity to antibodies raised against type I collagen, and amino acid analyses of soluble proteins extracted from the bone exhibit a composition indicative of structural proteins or their breakdown products. These data are corroborated by synchrotron radiation-based infrared microspectroscopic studies demonstrating that amino acid containing matter is located in bone matrix fibrils that express imprints of the characteristic 67 nm D-periodicity typical of collagen. Moreover, the fibrils differ significantly in spectral signature from those of potential modern bacterial contaminants, such as biofilms and collagen-like proteins. Thus, the preservation of primary soft tissues and biomolecules is not limited to large-sized bones buried in fluvial sandstone environments, but also occurs in relatively small-sized skeletal elements deposited in marine sediments.

  8. Investigation of amino acid δ 13C signatures in bone collagen to reconstruct human palaeodiets using liquid chromatography-isotope ratio mass spectrometry

    Science.gov (United States)

    Choy, Kyungcheol; Smith, Colin I.; Fuller, Benjamin T.; Richards, Michael P.

    2010-11-01

    This research presents the individual amino acid δ 13C values in bone collagen of humans ( n = 9) and animals ( n = 27) from two prehistoric shell midden sites in Korea. We obtained complete baseline separation of 16 of the 18 amino acids found in bone collagen by using liquid chromatography-isotope ratio mass spectrometry (LC-IRMS). The isotopic results reveal that the humans and animals in the two sites had similar patterns in essential amino acids (EAAs) and non-essential amino acids (NEAAs). The EAA and NEAA δ 13C values in humans are intermediate between those in marine and terrestrial animals. However, the threonine δ 13C values in humans and animals measured in this study are more highly enriched than those of other amino acids. At both sites, all amino acids in marine animals are 13C-enriched relative to those of the terrestrial animals. The isotopic evidence suggests that the Tongsamdong human had EAAs and NEAAs from marine food resources, while the Nukdo humans mainly had EAAs from terrestrial food resources but obtained NEAAs from both terrestrial and marine resources. The δ 13C isotopic differences in amino acids between marine and terrestrial animals were the largest for glycine (NEAA) and histidine (EAA) and the smallest for tyrosine (NEAA) and phenylalanine (EAA). In addition, threonine among the EAAs also had a large difference (˜8‰) in δ 13C values between marine and terrestrial animals, and has the potential to be used as an isotopic marker in palaeodietary studies. Threonine δ 13C values were used in conjunction with the established Δ 13C Glycine-phenylalanine values and produced three distinct dietary groups (terrestrial, omnivorous, and marine). In addition, threonine δ 13C values and Δ 13C Serine-phenylalanine values were discovered to separate between two dietary groups (terrestrial vs. marine), and these δ 13C values may provide a potential new indicator for investigating the distinction between marine and terrestrial protein

  9. Pulp revascularization using platelet rich plasma autologous or in conjunction with a collagen matrix as a therapeutic possibility for teeth with an open apex necrotic pulp and / or periapical pathology.

    OpenAIRE

    Camargo Guevara, Paula Alejandra; Sossa Rojas, Henry

    2014-01-01

    Objective: Describe the use of the Autologous Platelet-Rich Plasma or in combination with a collagen matrix as a potential revascularization therapy in teeth with open apices, necrotic pulp and/or periapical lesion. Methods: A thematic literature searchwas conducted from 2007 to 2013 using electronic means,  databases and journals with high impact on endodontic. Results: Regenerative endodontic is a biological based procedure  designed to replace structures that have been damaged, diseased or...

  10. Adipose-derived mesenchymal stem cells from the sand rat: transforming growth factor beta and 3D co-culture with human disc cells stimulate proteoglycan and collagen type I rich extracellular matrix

    OpenAIRE

    Tapp, Hazel; Deepe, Ray; Ingram, Jane A; Kuremsky, Marshall; Hanley, Edward N; Gruber, Helen E.

    2008-01-01

    Introduction Adult mesenchymal stem cell therapy has a potential application in the biological treatment of disc degeneration. Our objectives were: to direct adipose-derived mesenchymal stem cells (AD-MSC) from the sand rat to produce a proteoglycan and collagen type I extracellular matrix (ECM) rich in known ECM components of the annulus fibrosis of disc; and to stimulate proteoglycan production by co-culture of human annulus cells with AD-MSC. Methods AD-MSC were isolated and characterised ...

  11. Tissue-specific calibration of extracellular matrix material properties by transforming growth factor-β and Runx2 in bone is required for hearing

    OpenAIRE

    Chang, Jolie L; Brauer, Delia S.; Johnson, Jacob; Chen, Carol G.; Akil, Omar; Balooch, Guive; Humphrey, Mary Beth; Chin, Emily N.; Porter, Alexandra E.; Butcher, Kristin; Ritchie, Robert O.; Schneider, Richard A; Lalwani, Anil; Derynck, Rik; Marshall, Grayson W.

    2010-01-01

    By investigating the role of bone quality in hearing, this study provides evidence that signaling pathways and lineage-specific transcription factors cooperate to define the tissue-specific and functionally essential material properties of the extracellular matrix.

  12. Fabrication of bioactive composite scaffolds by electrospinning for bone regeneration

    NARCIS (Netherlands)

    Nandakumar, Anandkumar; Fernandes, Hugo; Boer, de Jan; Moroni, Lorenzo; Habibovic, Pamela; Blitterswijk, van Clemens A.

    2010-01-01

    Electrospun scaffolds are widely used for various biomedical applications. In this study, we prepared electrospun bioactive composite scaffolds combining hydroxyapatite, collagen (Col) and a synthetic polymer—PolyActive™—to mimic naturally occurring extracellular matrix for in situ bone regeneration

  13. Collagen based polyurethanes—A review of recent advances and perspective.

    Science.gov (United States)

    Zuber, Mohammad; Zia, Fatima; Zia, Khalid Mahmood; Tabasum, Shazia; Salman, Mahwish; Sultan, Neelam

    2015-09-01

    Collagen is mostly found in fibrous tissues such as tendons, ligaments and skin. Collagen makes up approximately 30% of the proteins within the body. These are tough and strong structures found all over the body: in bones, tendons and ligaments. Collagen being the most abundant protein provides tensile strength via cell matrix interactions to tissue architecture. Biomimetic materials of collagen origin gained wide spread acceptance in clinical applications. Vitamin C deficiency causes scurvy a serious and painful disease in which defective collagen prevents the formation of strong connective tissue, gums deteriorate and bleed, with loss of teeth; skin discolors, and wounds do not heal. Effective collagens prevent the manifestation of such disorders. Polyurethanes on the other hand are frequently used for various applications as they offered in wide-ranging of compositions, properties and complex structures. Collagen/PU bio-composites have potential array for biomedical applications. Considering versatile properties of the elongated fibrils and wide industrial and biomedical applications including biocompatibility of polyurethane, this review shed a light on collagen based polyurethane materials with their potential applications especially focusing the bio-medical field. PMID:26144910

  14. Elucidation of the Potential Roles of Matrix Metalloproteinases in Skeletal Biology

    OpenAIRE

    Krane, Stephen Martin

    2002-01-01

    Irreversible destruction of joint structures is a major feature of osteoarthritis and rheumatoid arthritis. Fibrillar collagens in bone, cartilage and other soft tissues are critical for optimal joint form and function. Several approaches can be used to ascertain the role of collagenases, matrix metalloproteinases, in proteolysis of joint collagens in arthritis. These approaches include identifying spontaneous genetic disorders of the enzymes and substrates in humans and animals, as well as e...

  15. Fibrinogen is a ligand for the Staphylococcus aureus Microbial Surface Components Recognizing Adhesive Matrix Molecules (MSCRAMM) Bone sialoprotein-binding protein (Bbp)

    OpenAIRE

    Foster, Timothy

    2011-01-01

    PUBLISHED MSCRAMMs (microbial surface components recognizing adhesive matrix molecules) are bacterial surface proteins mediating adherence of the microbes to components of the extracellular matrix of the host. On Staphylococci the MSCRAMMs often have multiple ligands. Consequently we hypothesized that the S. aureus MSCRAMM Bbp (bone sialoprotein-binding protein) might recognize host molecules other than the identified bone protein. A ligand screen revealed that Bbp binds human fibrinogen (...

  16. Fibrinogen Is a Ligand for the Staphylococcus aureus Microbial Surface Components Recognizing Adhesive Matrix Molecules (MSCRAMM) Bone Sialoprotein-binding Protein (Bbp)

    OpenAIRE

    Vazquez, Vanessa; Liang, Xiaowen; Horndahl, Jenny K.; Ganesh, Vannakambadi K.; Smeds, Emanuel; Foster, Timothy J.; Hook, Magnus

    2011-01-01

    Microbial surface components recognizing adhesive matrix molecules (MSCRAMMs) are bacterial surface proteins mediating adherence of the microbes to components of the extracellular matrix of the host. On Staphylococci, the MSCRAMMs often have multiple ligands. Consequently, we hypothesized that the Staphylococcus aureus MSCRAMM bone sialoprotein-binding protein (Bbp) might recognize host molecules other than the identified bone protein. A ligand screen revealed that Bbp binds human fibrinogen ...

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

    OpenAIRE

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

    2003-01-01

    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 f...

  18. Optimal Seeding Densities for In Vitro Chondrogenesis of Two- and Three-Dimensional-Isolated and -Expanded Bone Marrow-Derived Mesenchymal Stromal Stem Cells Within a Porous Collagen Scaffold

    OpenAIRE

    Bornes, Troy D.; Jomha, Nadr M; Mulet-Sierra, Aillette; Adesida, Adetola B.

    2016-01-01

    Bone marrow-derived mesenchymal stromal stem cells (BMSCs) are a promising cell source for treating articular cartilage defects. The objective of this study was to assess the impact of cell seeding density within a collagen I scaffold on in vitro BMSC chondrogenesis following isolation and expansion in two-dimensional (2D) and three-dimensional (3D) environments. It was hypothesized that both expansion protocols would produce BMSCs capable of hyaline-like chondrogenesis with an optimal seedin...

  19. Human Bone Marrow Mesenchymal Stem Cell Behaviors on PCL/Gelatin Nanofibrous Scaffolds Modified with A Collagen IV-Derived RGD-Containing Peptide

    Directory of Open Access Journals (Sweden)

    Ali Mota

    2014-03-01

    Full Text Available Objective: We introduce an RGD (Arg-Gly-Asp-containing peptide of collagen IV origin that possesses potent cell adhesion and proliferation properties. Materials and Methods: In this experimental study, the peptide was immobilized on an electrospun nanofibrous polycaprolactone/gelatin (PCL/Gel hybrid scaffold by a chemical bonding approach to improve cell adhesion properties of the scaffold. An iodine-modified phenylalanine was introduced in the peptide to track the immobilization process. Native and modified scaffolds were characterized with scanning electron microscopy (SEM and fourier transform infrared spectroscopy (FTIR. We studied the osteogenic and adipogenic differentiation potential of human bone marrow-derived mesenchymal stem cells (hBMSCs. In addition, cell adhesion and proliferation behaviors of hBMSCs on native and peptide modified scaffolds were evaluated by 3-(4,5-dimethylthiazol-2-yl-2,5-diphenyltetrazolium bromide (MTT assay and 4',6-diamidino-2-phenylindole (DAPI staining, and the results compared with tissue culture plate, as the control. Results: FTIR results showed that the peptide successfully immobilized on the scaffold. MTT assay and DAPI staining results indicated that peptide immobilization had a dramatic effect on cell adhesion and proliferation. Conclusion: This peptide modified nanofibrous scaffold can be a promising biomaterial for tissue engineering and regenerative medicine with the use of hBMSCs.

  20. Use of a collagen-elastin matrix as transport carrier system to transfer proliferating epidermal cells to human dermis in vitro.

    Science.gov (United States)

    Waaijman, Taco; Breetveld, Melanie; Ulrich, Magda; Middelkoop, Esther; Scheper, Rik J; Gibbs, Susan

    2010-01-01

    This in vitro study describes a novel cell culture, transport, and transfer protocol that may be highly suitable for delivering cultured proliferating keratinocytes and melanocytes to large open skin wounds (e.g., burns). We have taken into account previous limitations identified using other keratinocyte transfer techniques, such as regulatory issues, stability of keratinocytes during transport (single cell suspensions undergo terminal differentiation), ease of handling during application, and the degree of epidermal blistering resulting after transplantation (both related to transplanting keratinocyte sheets). Large numbers of proliferating epidermal cells (EC) (keratinocytes and melanocytes) were generated within 10-14 days and seeded onto a three-dimensional matrix composed of elastin and collagen types I, III, and V (Matriderm®), which enabled easy and stable transport of the EC for up to 24 h under ambient conditions. All culture conditions were in accordance with the regulations set by the Dutch Central Committee on Research Involving Human Subjects (CCMO). As an in vitro model system for clinical in vivo transfer, the EC were then transferred from Matriderm onto human acellular dermis during a period of 3 days. After transfer the EC maintained the ability to regenerate into a fully differentiated epidermis containing melanocytes on the human dermis. Proliferating keratinocytes were located in the basal layer and keratin-10 expression was located in differentiating suprabasal layers similar to that found in human epidermis. No blistering was observed (separation of the epidermis from the basement membrane). Keratin-6 expression was strongly upregulated in the regenerating epidermis similar to normal wound healing. In summary, we show that EC-Matriderm contains viable, metabolically active keratinocytes and melanocytes cultured in a manner that permits easy transportation and contains epidermal cells with the potential to form a pigmented reconstructed

  1. Imaging Mass Spectrometry by Matrix-Assisted Laser Desorption/Ionization and Stress-Strain Measurements in Iontophoresis Transepithelial Corneal Collagen Cross-Linking

    Directory of Open Access Journals (Sweden)

    Paolo Vinciguerra

    2014-01-01

    Full Text Available Purpose. To compare biomechanical effect, riboflavin penetration and distribution in transepithelial corneal collagen cross-linking with iontophoresis (I-CXL, with standard cross linking (S-CXL and current transepithelial protocol (TE-CXL. Materials and Methods. The study was divided into two different sections, considering, respectively, rabbit and human cadaver corneas. In both sections corneas were divided according to imbibition protocols and irradiation power. Imaging mass spectrometry by matrix-assisted laser desorption/ionization (MALDI-IMS and stress-strain measurements were used. Forty-eight rabbit and twelve human cadaver corneas were evaluated. Results. MALDI-IMS showed a deep riboflavin penetration throughout the corneal layers with I-CXL, with a roughly lower concentration in the deepest layers when compared to S-CXL, whereas with TE-CXL penetration was considerably less. In rabbits, there was a significant increase (by 71.9% and P=0.05 in corneal rigidity after I-CXL, when compared to controls. In humans, corneal rigidity increase was not significantly different among the subgroups. Conclusions. In rabbits, I-CXL induced a significant increase in corneal stiffness as well as better riboflavin penetration when compared to controls and TE-CXL but not to S-CXL. Stress-strain in human corneas did not show significant differences among techniques, possibly because of the small sample size of groups. In conclusion, I-CXL could be a valid alternative to S-CXL for riboflavin delivery in CXL, preserving the epithelium.

  2. Expression of bone morphogenic protein 2/4, transforming growth factor-β1, and bone matrix protein expression in healing area between vascular tibia grafts and irradiated bone-experimental model of osteonecrosis

    International Nuclear Information System (INIS)

    Purpose: For the surgical treatment of osteoradionecrosis after multimodal therapy of head-and-neck cancers, free vascular bone grafts are used to reconstruct osseous structures in the previously irradiated graft bed. Reduced, or even absent osseous healing in the transition area between the vascular graft and the irradiated graft bed represents a clinical problem. Inflammatory changes and fibrosis lead to delayed healing, triggered by bone morphogentic protein 2/4 (BMP2/4) and transforming growth factor (TGF)-β1. Given the well-known fibrosis-inducing activity of TGF-β1, an osteoinductive effect has been reported for BMP2/4. However, the influence of irradiation (RT) on this cytokine expression remains elusive. Therefore, the aim of the present in vivo study was to analyze the expression of BMP2/4, TGF-β1, collagen I, and osteocalcin in the transition area between the bone graft and the graft bed after RT. Methods and materials: Twenty Wistar rats (male, weight 300-500 g) were used in this study. A free vascular tibia graft was removed in all rats and maintained pedicled in the groin region. Ten rats underwent RT with 5 x 10 Gy to the right tibia, the remainder served as controls. After 4 weeks, the previously removed tibia grafts were regrafted into the irradiated (Group 1) and nonirradiated (Group 2) graft beds. The interval between RT and grafting was 4 weeks. After a 4-week osseous healing period, the bone grafts were removed, and the transition area between the nonirradiated graft and the irradiated osseous graft bed was examined histomorphometrically (National Institutes of Health imaging program) and immunohistochemically (avidin-biotin-peroxidase complex) for the expression of BMP2/4, TGF-β1, collagen I, and osteocalcin. Results: Absent or incomplete osseous healing of the graft was found in 9 of 10 rats after RT with 50 Gy and in 1 of 10 of the rats with nonirradiated osseous grafts. Histomorphometrically, the proportion of osseous healing in the

  3. Experimental Study of Diffusion Coefficients of Water through the Collagen: Apatite Porosity in Human Trabecular Bone Tissue

    Directory of Open Access Journals (Sweden)

    Franco Marinozzi

    2014-01-01

    Full Text Available We firstly measured the swelling of single trabeculae from human femur heads during water imbibition. Since the swelling is caused by water diffusing from external surfaces to the core of the sample, by measuring the sample swelling over time, we obtained direct information about the transport of fluids through the intimate constituents of bone, where the mineralization process takes place. We developed an apparatus to measure the free expansion of the tissue during the imbibition. In particular, we measured the swelling along three natural axes (length L, width W, and thickness T of plate-like trabeculae. For this aim, we developed a 3D analytical model of the water uptake by the sample that was performed according to Fickian transport mechanism. The results were then utilized to predict the swelling over time along the three sample directions (L, W, T and the apparent diffusion coefficients DT, DW, and DL.

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

    Science.gov (United States)

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

    2015-12-01

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

  5. In vitro colonization of the muscle extracellular matrix components by Escherichia coli O157:H7: the influence of growth medium, temperature and pH on initial adhesion and induction of biofilm formation by collagens I and III.

    Directory of Open Access Journals (Sweden)

    Caroline Chagnot

    Full Text Available Enterohemorrhagic Escherichia coli (EHEC O157:H7 are responsible for repeated food-poisoning cases often caused by contaminated burgers. EHEC infection is predominantly a pediatric illness, which can lead to life-threatening diseases. Ruminants are the main natural reservoir for EHEC and food contamination almost always originates from faecal contamination. In beef meat products, primary bacterial contamination occurs at the dehiding stage of slaughtering. The extracellular matrix (ECM is the most exposed part of the skeletal muscles in beef carcasses. Investigating the adhesion to the main muscle fibrous ECM proteins, insoluble fibronectin, collagen I, III and IV, laminin-α2 and elastin, results demonstrated that the preceding growth conditions had a great influence on subsequent bacterial attachment. In the tested experimental conditions, maximal adhesion to fibril-forming collagens I or III occurred at 25°C and pH 7. Once initially adhered, exposure to lower temperatures, as applied to meat during cutting and storage, or acidification, as in the course of post-mortem physiological modifications of muscle, had no effect on detachment, except at pHu. In addition, dense biofilm formation occurred on immobilized collagen I or III and was induced in growth medium supplemented with collagen I in solution. From this first comprehensive investigation of EHEC adhesion to ECM proteins with respect to muscle biology and meat processing, new research directions for the development of innovative practices to minimize the risk of meat contamination are further discussed.

  6. Collagen in organ development

    Science.gov (United States)

    Hardman, P.; Spooner, B. S.

    1992-01-01

    It is important to know whether microgravity will adversely affect developmental processes. Collagens are macromolecular structural components of the extracellular matrix (ECM) which may be altered by perturbations in gravity. Interstitial collagens have been shown to be necessary for normal growth and morphogenesis in some embryonic organs, and in the mouse salivary gland, the biosynthetic pattern of these molecules changes during development. Determination of the effects of microgravity on epithelial organ development must be preceded by crucial ground-based studies. These will define control of normal synthesis, secretion, and deposition of ECM macromolecules and the relationship of these processes to morphogenesis.

  7. Depot specific differences in the adipogenic potential of precursors are mediated by collagenous extracellular matrix and Flotillin 2 dependent signaling

    Directory of Open Access Journals (Sweden)

    Gerald Grandl

    2016-10-01

    Conclusions: We show that adipose tissue SVF secretes collagenous ECM, which directly modulates terminal differentiation of adipocyte precursors in a depot specific manner. These data demonstrate the importance of the tissue microenvironment in preadipocyte differentiation.

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

    Science.gov (United States)

    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 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

  9. Increased expression of osteonectin and osteopontin, two bone matrix proteins, in human breast cancer.

    OpenAIRE

    Bellahcène, A.; Castronovo, V.

    1995-01-01

    Microcalcifications are a common phenomenon associated with breast cancer and are often the only mammographic sign of a malignant breast disease. Although microcalcifications are not restricted to breast cancer and can be also associated with benign lesions, it is noteworthy that they are composed exclusively of hydroxyapatite in breast carcinoma. Hydroxyapatite is the bone-associated phosphocalcic crystal the deposition of which in bone tissue requires the coordinated expression of several m...

  10. Cell cytoskeletal changes effected by static compressive stress lead to changes in the contractile properties of tissue regenerative collagen membranes.

    Science.gov (United States)

    Gellynck, K; Shah, R; Deng, D; Parkar, M; Liu, W; Knowles, J C; Buxton, P

    2013-01-01

    Static compressive stress can influence the matrix, which subsequently affects cell behaviour and the cell's ability to further transform the matrix. This study aimed to assess response to static compressive stress at different stages of osteoblast differentiation and assess the cell cytoskeleton's role as a conduit of matrix-derived stimuli. Mouse bone marrow mesenchymal stem cells (MSCs) (D1 ORL UVA), osteoblastic cells (MC3T3-E1) and post-osteoblast/pre-osteocyte-like cells (MLO-A5) were seeded in hydrated and compressed collagen gels. Contraction was quantified macroscopically, and cell morphology, survival, differentiation and mineralisation assessed using confocal microscopy, alamarBlue® assay, real-time quantitative reverse transcription polymerase chain reaction (RT-qPCR) and histological stains, respectively. Confocal microscopy demonstrated cell shape changes and favourable microfilament organisation with static compressive stress of the collagen matrix; furthermore, cell survival was greater compared to the hydrated gels. The stage of osteoblast differentiation determined the degree of matrix contraction, with MSCs demonstrating the greatest amount. Introduction of microfilament disrupting inhibitors confirmed that pre-stress and tensegrity forces were under the influence of gel density, and there was increased survival and differentiation of the cells within the compressed collagen compared to the hydrated collagen. There was also relative stiffening and differentiation with time of the compressed cell-seeded collagen, allowing for greater manipulation. In conclusion, the combined collagen chemistry and increased density of the microenvironment can promote upregulation of osteogenic genes and mineralisation; MSCs can facilitate matrix contraction to form an engineered membrane with the potential to serve as a 'pseudo-periosteum' in the regeneration of bone defects. PMID:23813054

  11. Cell cytoskeletal changes effected by static compressive stress lead to changes in the contractile properties of tissue regenerative collagen membranes

    Directory of Open Access Journals (Sweden)

    K Gellynck

    2013-06-01

    Full Text Available Static compressive stress can influence the matrix, which subsequently affects cell behaviour and the cell’s ability to further transform the matrix. This study aimed to assess response to static compressive stress at different stages of osteoblast differentiation and assess the cell cytoskeleton’s role as a conduit of matrix-derived stimuli. Mouse bone marrow mesenchymal stem cells (MSCs (D1 ORL UVA, osteoblastic cells (MC3T3-E1 and post-osteoblast/pre-osteocyte-like cells (MLO-A5 were seeded in hydrated and compressed collagen gels. Contraction was quantified macroscopically, and cell morphology, survival, differentiation and mineralisation assessed using confocal microscopy, alamarBlue® assay, real-time quantitative reverse transcription polymerase chain reaction (RT-qPCR and histological stains, respectively. Confocal microscopy demonstrated cell shape changes and favourable microfilament organisation with static compressive stress of the collagen matrix; furthermore, cell survival was greater compared to the hydrated gels. The stage of osteoblast differentiation determined the degree of matrix contraction, with MSCs demonstrating the greatest amount. Introduction of microfilament disrupting inhibitors confirmed that pre-stress and tensegrity forces were under the influence of gel density, and there was increased survival and differentiation of the cells within the compressed collagen compared to the hydrated collagen. There was also relative stiffening and differentiation with time of the compressed cell-seeded collagen, allowing for greater manipulation. In conclusion, the combined collagen chemistry and increased density of the microenvironment can promote upregulation of osteogenic genes and mineralisation; MSCs can facilitate matrix contraction to form an engineered membrane with the potential to serve as a ‘pseudo-periosteum’ in the regeneration of bone defects.

  12. Combined Effect of a Microporous Layer and Type I Collagen Coating on a Biphasic Calcium Phosphate Scaffold for Bone Tissue Engineering

    OpenAIRE

    Mun-Hwan Lee; Changkook You; Kyo-Han Kim

    2015-01-01

    In this study, type I collagen was coated onto unmodified and modified microporous biphasic calcium phosphate (BCP) scaffolds. Surface characterization using a scanning electron microscope (SEM) and a surface goniometer confirmed the modification of the BCP coating. The quantity of the collagen coating was investigated using Sirius Red staining, and quantitative assessment of the collagen coating showed no significant differences between the two groups. MG63 cells were used to evaluate cell p...

  13. The Effect of Bioceramic Composite Extracellular Matrixes Used to Repair Bone Deficiency on Relevant Blood Biochemical Indices

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    At the base of experimental animal model construction of bone defect in New Zealand rabbit, the promoting repair effect of bioactive ceramics on bone defect as well as its machanism was studied through testing body mineral elements, enzymes related to bone morphogenetic proteins and some biochemical indexes. Refering to some documents, materials of TCP, CHA and HA were combined and TCP/BMP/ TCP-β1 and CHA/BMP/ TCP-β1, HA/BMP/ TCP-β1 composite materials were made. All kinds of them were implanted into the radial defect site of rabbit, respectively. The chosen blood indexes (Ca, P, ALP, GGT, AST, ALT, TPA, BUN and Cr) were tested by colorimetry, speed rate and bromocresol green testing methods. No abnormal effects were found in any animal after operation. Serum concentrations of Ca, P and ALP were increased with the length of time in all groups of the three kinds of composite material, mixed material and pure materials. The increases in composite material groups were more significant ( P <0.05). Comparison of the three kinds of material showed TCP > CHA > HA. There was a tendency of increased TPA and decreased BUN with the length of time. There was no significant difference between the composite material groups and pure material group (P >0.05). The three kinds of bioactive ceramics composed of extracellular matrix could increase the serum concentrations of Ca and P and activity of ALP after being implanted into defect bone and showed some repairing capacity. This provided a new area of machanism study of bone defect repair by biomaterials.

  14. Bone

    Science.gov (United States)

    Helmberger, Thomas K.; Hoffmann, Ralf-Thorsten

    The typical clinical signs in bone tumours are pain, destruction and destabilization, immobilization, neurologic deficits, and finally functional impairment. Primary malignant bone tumours are a rare entity, accounting for about 0.2% of all malignancies. Also benign primary bone tumours are in total rare and mostly asymptomatic. The most common symptomatic benign bone tumour is osteoid osteoma with an incidence of 1:2000.

  15. Biocompatibility of Novel Type I Collagen Purified from Tilapia Fish Scale: An In Vitro Comparative Study

    OpenAIRE

    Jia Tang; Takashi Saito

    2015-01-01

    Type I collagen (COL-1) is the prevailing component of the extracellular matrix in a number of tissues including skin, ligament, cartilage, bone, and dentin. It is the most widely used tissue-derived natural polymer. Currently, mammalian animals, including pig, cow, and rat, are the three major sources for purification of COL-1. To reduce the risk of zoonotic infectious diseases transmission, minimize the possibility of immunogenic reaction, and avoid problems related to religious issues, exp...

  16. Mechanical properties, biological activity and protein controlled release by poly(vinyl alcohol)-bioglass/chitosan-collagen composite scaffolds: a bone tissue engineering applications.

    Science.gov (United States)

    Pon-On, Weeraphat; Charoenphandhu, Narattaphol; Teerapornpuntakit, Jarinthorn; Thongbunchoo, Jirawan; Krishnamra, Nateetip; Tang, I-Ming

    2014-05-01

    In the present study, composite scaffolds made with different weight ratios (0.5:1, 1:1 and 2:1) of bioactive glass (15Ca:80Si:5P) (BG)/polyvinyl alcohol (PVA) (PVABG) and chitosan (Chi)/collagen (Col) (ChiCol) were prepared by three mechanical freeze-thaw followed by freeze-drying to obtain the porous scaffolds. The mechanical properties and the in vitro biocompatibility of the composite scaffolds to simulated body fluid (SBF) and to rat osteoblast-like UMR-106 cells were investigated. The results from the studies indicated that the porosity and compressive strength were controlled by the weight ratio of PVABG:ChiCol. The highest compressive modulus of the composites made was 214.64 MPa which was for the 1:1 weight ratio PVABG:ChiCol. Mineralization study in SBF showed the formation of apatite crystals on the PVABG:ChiCol surface after 7 days of incubation. In vitro cell availability and proliferation tests confirmed the osteoblast attachment and growth on the PVABG:ChiCol surface. MTT and ALP tests on the 1:1 weight ratio PVABG:ChiCol composite indicated that the UMR-106 cells were viable. Alkaline phosphatase activity was found to increase with increasing culturing time. In addition, we showed the potential of PVABG:ChiCol drug delivery through PBS solution studies. 81.14% of BSA loading had been achieved and controlled release for over four weeks was observed. Our results indicated that the PVABG:ChiCol composites, especially the 1:1 weight ratio composite exhibited significantly improved mechanical, mineral deposition, biological properties and controlled release. This made them potential candidates for bone tissue engineering applications.

  17. Immunohistochemical findings type I and type II collagen in prenatal mouse mandibular condylar cartilage compared with the tibial anlage.

    Science.gov (United States)

    Ishii, M; Suda, N; Tengan, T; Suzuki, S; Kuroda, T

    1998-07-01

    In growing animals the mandibular condylar cartilage serves not only as an articular but also as a growth cartilage, yet, condylar cartilage has some characteristic features that are not found in growth cartilage. For example, some reports suggest that type I collagen, which is not seen in the growth plate cartilage of long bones, is present in the extracellular matrix of condylar cartilage postnatally. Here, the condylar and limb bud cartilage of fetal mice was examined. The distribution of type I and type II collagen in condylar cartilage was already different from that in the limb bud at the first appearance of the cartilage. Type I collagen was demonstrated in the extracellular matrix of the condylar cartilage that first appeared on day 15 of gestation. However, the reaction for type II collagen was much weaker than that for type I collagen. On day 18 of gestation, type I collagen was still found throughout the cell layers but became gradually weaker with depth. Type II collagen was limited exclusively to the deeper layers at this stage. These findings are different from those in the limb bud cartilage, indicating a characteristic feature of the cells in the condylar cartilage present from the prenatal period.

  18. Bone Microenvironment Modulates Expression and Activity of Cathepsin B in Prostate Cancer

    Directory of Open Access Journals (Sweden)

    Izabela Podgorski

    2005-03-01

    Full Text Available Prostate cancers metastasize to bone leading to osteolysis. Here we assessed proteolysis of DOcollagen I (a bone matrix protein and, for comparison, DO-collagen IV, by living human prostate carcinoma cells in vitro. Both collagens were degraded, this degradation was reduced by inhibitors of matrix metallo, serine, cysteine proteases. Because secretion of the cysteine protease cathepsin B is increased in human breast fibroblasts grown on collagen I gels, we analyzed cathepsin B levels and secretion in prostate cells grown on collagen I gels. Levels and secretion were increased only in DU145 cells-cells that expressed the highest baseline levels of cathepsin B. Secretion of cathepsin B was also elevated in DU145 cells grown in vitro on human bone fragments. We further investigated the effect of the bone microenvironment on cathepsin B expression and activity in vivo in a SCID-human model of prostate bone metastasis. High levels of cathepsin B protein and activity were found in DU145, PC3, LNCaP bone tumors, although the PC3 and LNCaP cells had exhibited low cathepsin B expression in vitro. Our results suggest that tumor-stromal interactions in the context of the bone microenvironment can modulate the expression of the cysteine protease cathepsin B.

  19. Mutations in FKBP10, which result in Bruck syndrome and recessive forms of osteogenesis imperfecta, inhibit the hydroxylation of telopeptide lysines in bone collagen

    NARCIS (Netherlands)

    Schwarze, Ulrike; Cundy, Tim; Pyott, Shawna M.; Christiansen, Helena E.; Hegde, Madhuri R.; Bank, Ruud A.; Pals, Gerard; Ankala, Arunkanth; Conneely, Karen; Seaver, Laurie; Yandow, Suzanne M.; Raney, Ellen; Babovic-Vuksanovic, Dusica; Stoler, Joan; Ben-Neriah, Ziva; Segel, Reeval; Lieberman, Sari; Siderius, Liesbeth; Al-Aqeel, Aida; Hannibal, Mark; Hudgins, Louanne; McPherson, Elizabeth; Clemens, Michele; Sussman, Michael D.; Steiner, Robert D.; Mahan, John; Smith, Rosemarie; Anyane-Yeboa, Kwame; Wynn, Julia; Chong, Karen; Uster, Tami; Aftimos, Salim; Sutton, V. Reid; Davis, Elaine C.; Kim, Lammy S.; Weis, Mary Ann; Eyre, David; Byers, Peter H.

    2013-01-01

    Although biallelic mutations in non-collagen genes account for 10 of individuals with osteogenesis imperfecta, the characterization of these genes has identified new pathways and potential interventions that could benefit even those with mutations in type I collagen genes. We identified mutations in

  20. A multicentre randomized controlled clinical trial on the treatment of intrabony defects with enamel matrix derivatives/synthetic bone graft or enamel matrix derivatives alone?Results after 12 months

    OpenAIRE

    Meyle, Joerg; Hoffmann, Thomas; Topoll, Heinz; Heinz, Bernd; Al-Machot, Eli; Jervøe-Storm, Pia-Merete; Jepsen, Søren; Eickholz, Peter; Meiss, Christian

    2011-01-01

    Abstract Objectives: Comparison of clinical and radiographic outcomes of a combination of enamel matrix derivatives (EMD) and a synthetic bone graft (SBG) with EMD alone in wide and deep 1- and 2- wall intrabony defects 12 months after treatment. Method: In 73 patients with chronic periodontitis and one intrabony lesion, defects were randomly assigned to EMD/SBG (test) or EMD (control). Bone sounding, attachment levels, probing pocket depths, bleeding on probing and recessions w...

  1. Origin of Matrix-Producing Cells That Contribute to Aortic Fibrosis in Hypertension.

    Science.gov (United States)

    Wu, Jing; Montaniel, Kim Ramil C; Saleh, Mohamed A; Xiao, Liang; Chen, Wei; Owens, Gary K; Humphrey, Jay D; Majesky, Mark W; Paik, David T; Hatzopoulos, Antonis K; Madhur, Meena S; Harrison, David G

    2016-02-01

    Various hypertensive stimuli lead to exuberant adventitial collagen deposition in large arteries, exacerbating blood pressure elevation and end-organ dam