Browsing by Subject "OSTEOGENIC DIFFERENTIATION"

Now showing 1 - 4 of 4
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    The effect of autologous bone marrow stromal cells differentiated on scaffolds for canine tibial bone reconstruction
    (TAYLOR & FRANCIS LTD) Özdal-Kurt, F; Tuglu, I; Vatansever, HS; Tong, S; Deliloglu-Gürhan, SI
    Bone marrow contains mesenchymal stem cells that form many tissues. Various scaffolds are available for bone reconstruction by tissue engineering. Osteoblastic differentiated bone marrow stromal cells (BMSC) promote osteogenesis on scaffolds and stimulate bone regeneration. We investigated the use of cultured autologous BMSC on different scaffolds for healing defects in tibias of adult male canines. BMSC were isolated from canine humerus bone marrow, differentiated into osteoblasts in culture and loaded onto porous ceramic scaffolds including hydroxyapatite 1, hydroxyapatite gel and calcium phosphate. Osteoblast differentiation was verified by osteonectine and osteocalcine immunocytochemistry. The scaffolds with stromal cells were implanted in the tibial defect. Scaffolds without stromal cells were used as controls. Sections from the defects were processed for histological, ultrastructural, immunohistochemical and histomorphometric analyses to analyze the healing of the defects. BMSC were spread, allowed to proliferate and differentiate to osteoblasts as shown by alizarin red histochemistry, and osteocalcine and osteonectine immunostaining. Scanning electron microscopy showed that BMSC on the scaffolds were more active and adhesive to the calcium phosphate scaffold compared to the others. Macroscopic bone formation was observed in all groups, but scaffolds with stromal cells produced significantly better results. Bone healing occurred earlier and faster with stromal cells on the calcium phosphate scaffold and produced more callus compared to other scaffolds. Tissue healing and osteoblastic marker expression also were better with stromal cells on the scaffolds. Increased trabecula formation, cell density and decreased fibrosis were observed in the calcium phosphate scaffold with stromal cells. Autologous cultured stromal cells on the scaffolds were useful for healing of canine tibial bone defects. The calcium phosphate scaffold was the best for both cell differentiation in vitro and bone regeneration in vivo. It may be possible to improve healing of bone defects in humans using stem cells from bone marrow.
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    Potential Clinical Use of Differentiated Cells From Embryonic or Mesencyhmal Stem Cells in Orthopaedic Problems
    (BENTHAM SCIENCE PUBL LTD) Kurt, FO; Vatansever, HS
    Stem cells are classified by their tissue source. Embryonic stem cells that are derived from the inner cell mass of blastocyst stage embryos are highly proliferative in their undifferentiated state. A multipotent type of mesenchymal stem cells is isolated from various types of tissues such as bone marrow, fat tissue etc. The dynamics of embryonic and adult stem cell cycles are profoundly dissimilar from the culture of stem cells. After improving the culture conditions and differentiation potentials, differentiated stem cells are the first cells to be preferred in modern regenerative medicine and tissue engineering. This review article focuses on the cell-based therapy of orthopedic problems. We explore the challenges associated with bone repair and regeneration using embryonic or mesenchymal stem cells that are in undifferentiated or/and differentiated condition. This paper also discusses optimizing the best cell type, differentiation condition and using them on bone tissue engineering for future investigations.
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    Effect of pore architecture on the mesenchymal stem cell responses to graphene/polycaprolactone scaffolds prepared by solvent casting and robocasting
    (SPRINGER) Deliormanli, AM; Atmaca, H
    In the study graphene-containing porous, three dimensional polycaprolactone (PCL) scaffolds were prepared by solvent casting-salt leaching and robocasting methods for tissue engineering applications. Graphene nanopowders in the form of nanoflakes were incorporated into the polymer matrix at different concentrations namely 1, 3, 5 and 10 wt%. The dichloromethane was used as the solvent and sodium chloride crystals were utilized as the water-soluble porogen for the formation of an interconnected porous network (with non-oriented pores) inside the composite scaffolds in solvent casting-salt leaching method. On the other hand, acetone was utilized as solvent and PCL solutions were prepared at 20 wt% in robocasting method to construct scaffolds (with oriented pores) having a grid-like structure. The biological response of bone marrow mesenchymal stem cells seeded on these composite constructs having different architecture were tested using MTT method, live-dead cell viability assay and Alcian blue stanining. Cytotoxicity experiments revealed that mesenchymal stem cells did not show toxic response to composite robocast scaffolds. Cells proliferate and differentiate well on the surface of the robocast scaffolds compared to solvent-cast scaffolds under the same conditions. Results showed that scaffolds prepared in the study have potential to be used in cartilage tissue engineering in the presence of electric stimulation.
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    Response of mouse bone marrow mesenchymal stem cells to graphene-containing grid-like bioactive glass scaffolds produced by robocasting
    (SAGE PUBLICATIONS LTD) Deliormanli, AM; Türk, M; Atmaca, H
    In the study, three-dimensional, grid-like silicate-based bioactive glass scaffolds were manufactured using a robotic deposition technique. Inks were prepared by mixing 13-93 bioactive glass particles in Pluronic (R) F-127 solution. After deposition, scaffolds were dried at room temperature and sintered at 690 degrees C for 1 h. The surface of the sintered scaffolds was coated with graphene nanopowder (1, 3, 5, 10 wt%) containing poly(epsilon-caprolactone) solution. The in vitro mineralization ability of the prepared composite scaffolds was investigated in simulated body fluid. The surface of the simulated body fluid-treated scaffolds was analyzed using scanning electron microscopy to investigate the hydroxyapatite formation. Mechanical properties were tested under compression. Results revealed that graphene coating has no detrimental effect on the hydroxyapatite forming ability of the prepared glass scaffolds. On the other hand, it decreased the compression strength of the scaffolds at high graphene concentrations. The prepared grid-like bioactive glass-based composite scaffolds did not show toxic response to bone marrow mesenchymal stem cells. It was shown that stem cells seeded onto the scaffolds attached and proliferated well on the surface. Cells seeded on the scaffolds surface also demonstrated osteogenic differentiation under in vitro conditions in the absence of transforming growth factors.