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Osteoinductive Properties (osteoinductive + property)
Selected AbstractsBone Implants: (Osteoconductive and Osteoinductive Properties of Zeolite MFI Coatings on Titanium Alloys) Adv.ADVANCED FUNCTIONAL MATERIALS, Issue 24 2009Funct. Biocompatible zeolite anti-corrosion coatings have potential for success as bone scaffolding materials. In this work, reported by Y. Yan and co-workers, titanium-based dental implants are covered with zeolite MFI coatings to prevent against corrosion within the dental cavity. Zeolite coatings are non-toxic, and prevent the release of toxic ions from metals into tissue. The 3D micro-topology of the zeolites also enhances cell proliferation, differentiation, and surface adhesion. [source] Osteoconductive and Osteoinductive Properties of Zeolite MFI Coatings on Titanium AlloysADVANCED FUNCTIONAL MATERIALS, Issue 24 2009Rajwant S. Bedi Abstract The use of zeolite MFI-coated titanium alloy for bone cell growth and new bone formation in vitro is investigated. The corrosion-resistant MFI coating is shown to be osteoconductive and to promote proliferation of human fetal osteoblasts (hFOBs) as compared to bare titanium alloy, Ti6Al4V. The zeolite crystal microstructure appears to facilitate osteoblast adhesion and induces osteointegration, as evaluated with microscopy. In addition, the zeolite promotes the differentiation of hFOBs into mature osteoblasts, as well as the production of a mineralized matrix at earlier times in culture compared to Ti6Al4V, indicating higher osteoinductive properties of the MFI coating than titanium alone. A significant increase in the expression of the bone morphogenetic protein (BMP-2) gene is measured in hFOBs cultured on zeolite coatings compared to bare Ti6Al4V. This is the first report on highly corrosion-resistant zeolite MFI coatings on Ti6A14V alloys with the potential to be used as a material of improved osteointegration appropriate for bone tissue regeneration. [source] Natural bone collagen scaffold combined with OP-1 for bone formation induction in vivoJOURNAL OF BIOMEDICAL MATERIALS RESEARCH, Issue 2 2009Yu Qian Abstract The scaffold is a key element to osteogenic tissue engineering as it provides a microenvironment for bone formation. Natural bone collagen scaffold (NBCS) is a novel biomaterial scaffold acid-extracted from organic human bone. The objective of this study was to characterize NBCS and evaluate the osteoconductivity of the scaffold, in combination with osteogenic protein-1 (OP-1), using a rabbit posteolateral lumbar fusion model. Thirty two rabbits were divided into 4 experimental groups, autograft, NBCS alone, OP-1 alone or NBCS combined with OP-1. Bone formation was evaluated by micro-CT, quantitative histological analysis, immunohistochemistry and semi-quantitative RT-PCR at 6 weeks postoperatively. By scanning electronic microscope, we showed that NBCS maintains a porous, interconnecting microarchitecture. Micro-CT analysis demonstrated that NBCS combined with OP-1 significantly induced (p < 0.01) bone formation at the fusion site as compared to control groups. This was confirmed by quantitative histological analysis which demonstrated that the NBCS combined with OP-1 significantly enhanced bone matrix area (17.7 mm2) (p < 0.05) and bone marrow cavity size (71.3 mm2) (p < 0.05) as compared to the controls. Immunohistochemical assessment and RT-PCR also demonstrated that NBCS combined with OP-1 enhanced type I collagen and osteonectin expression. Together, these results suggest that NBCS is an effective scaffold for osteogenesis, and combined with growth factors such as OP-1, possesses both osteoconductive and osteoinductive properties that are sufficient for bone regeneration. © 2009 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2009 [source] Oxysterol-induced osteogenic differentiation of marrow stromal cells is regulated by Dkk-1 inhibitable and PI3-kinase mediated signalingJOURNAL OF CELLULAR BIOCHEMISTRY, Issue 2 2008Christopher M. Amantea Abstract Osteoporosis and its complications cause morbidity and mortality in the aging population, and result from increased bone resorption by osteoclasts in parallel with decreased bone formation by osteoblasts. A widely accepted strategy for improving bone health is targeting osteoprogenitor cells in order to stimulate their osteogenic differentiation and bone forming properties through the use of osteoinductive/anabolic factors. We previously reported that specific naturally occurring oxysterols have potent osteoinductive properties, mediated in part through activation of hedgehog signaling in osteoprogenitor cells. In the present report, we further demonstrate the molecular mechanism(s) by which oxysterols induce osteogenesis. In addition to activating the hedgehog signaling pathway, oxysterol-induced osteogenic differentiation is mediated through a Wnt signaling-related, Dkk-1-inhibitable mechanism. Bone marrow stromal cells (MSC) treated with oxysterols demonstrated increased expression of osteogenic differentiation markers, along with selective induced expression of Wnt target genes. These oxysterol effects, which occurred in the absence of ,-catenin accumulation or TCF/Lef activation, were inhibited by the hedgehog pathway inhibitor, cyclopamine, and/or by the Wnt pathway inhibitor, Dkk-1. Furthermore, the inhibitors of PI3-Kinase signaling, LY 294002 and wortmanin, inhibited oxysterol-induced osteogenic differentiation and induction of Wnt signaling target genes. Finally, activators of canonical Wnt signaling, Wnt3a and Wnt1, inhibited spontaneous, oxysterol-, and Shh-induced osteogenic differentiation of bone marrow stromal cells, suggesting the involvement of a non-canonical Wnt pathway in pro-osteogenic differentiation events. Osteogenic oxysterols are, therefore, important small molecule modulators of critical signaling pathways in pluripotent mesenchymal cells that regulate numerous developmental and post-developmental processes. J. Cell. Biochem. 105: 424,436, 2008. © 2008 Wiley-Liss, Inc. [source] Subcutaneous-induced membranes have no osteoinductive effect on macroporous HA-TCP in vivoJOURNAL OF ORTHOPAEDIC RESEARCH, Issue 2 2009Sylvain Catros Abstract Induced Membranes Technique was first described to enhance bone reconstruction of large osseous defects. Previous in vitro studies established their osteoinductive potential, due to the presence of opteoblasts precursors and to high amounts of growth factors contained within. The purpose of this study was to test in vivo the osteoinductive properties of induced membranes on a macroporous HA-TCP in a nonosseous subcutaneous site. Subcutaneous-induced membranes were obtained in 21 rabbits; 1 month later, the membranes were filled with a biphasic calcium phosphate material composed of 75% hydroxyapatite (HA) and 25% ,-tricalcium phosphate associated or not with autograft. Histological and immunohistochemical studies were performed on membrane biopsies. Undecalcified and decalcified sections were qualitatively and quantitatively analyzed. 45Ca uptake was observed and quantified on the sections using microimager analysis. Dense vascularity was found in the induced membranes. New bone formation was detected in the HA-TCP,+,autograft samples and increased significantly from 3 to 6 months (p,<,0.05). No bone was detected in the biomaterial graft alone in the induced membranes at any time. This study showed that induced membranes placed in a nonosseous site have no osteoinductive properties on a macroporous biphasic calcium phosphate biomaterial. © 2008 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 27:155,161, 2009 [source] Relevance of Osteoinductive Biomaterials in Critical-Sized Orthotopic DefectJOURNAL OF ORTHOPAEDIC RESEARCH, Issue 5 2006Pamela Habibovic Abstract Several publications have shown the phenomenon of osteoinduction by biomaterials to be real. However, whether the ability of a biomaterial to initiate bone formation in ectopic implantation sites improves the performance of such osteoinductive biomaterial in clinically relevant orthotopic sites remains unclear. No studies have been published in which osteoinductive potential of a biomaterial is directly related to its performance orthotopically. In this study, we compared osteoinductive and nonosteoinductive biphasic calcium,phosphate (BCP) ceramics ectopically and in a clinically relevant critical-sized orthotopic defect in goats. The two materials, BCP1150 and BCP1300, had similar chemical compositions, crystallinities, and macrostructures, but their microstructures differed significantly. BCP1150, sintered at a lower temperature, had a large amount of micropores, small average crystal size, and hence a high specific surface area. In contrast, BCP1300, with few micropores, had a significantly lower specific surface area as compared to BCP1150. Twelve-week intramuscular implantation in goats (n,=,10) showed that bone was induced in all BCP1150 implants, while no signs of bone formation were found in any of the BCP1300 implants. After 12 weeks of implantation in a bilateral critical-sized iliac wing defect in the same goats, BCP1150 showed significantly more bone than BCP1300. In addition, the analysis of fluorochrome markers, which were administered to the animals 4, 6, and 8 weeks after implantation to follow the bone growth dynamics, showed an earlier start of bone formation in BCP1150 as compared to BCP1300. Significantly better performance of an osteoinductive ceramic in a critical-sized orthotopic defect in a large animal model in comparison to a nonosteoinductive ceramic suggests osteoinduction to be clinically relevant. Further improvement of material osteoinductive properties is thus a significant step forward in the search for alternatives for autologous bone graft. © 2006 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res [source] | |||||||||||||