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BACKGROUND: The establishment of coculture system combined with physical factors and scaffold materials and the Induction of cytokines have become the focus of chondrogenlc differentiation of bone marrow mesenchymal stem cells. OBJECTIVE: To observe the effect of bone morphogenetic protein 7 combined with porous tantalum on chondrogenlc differentiation of bone marrow mesenchymal stem cells. METHODS: Bone marrow mesenchymal stem cells of Sprague-Dawley rats (provided by Beijing Huafukang Biology) were Isolated and cultured. Group Intervention: (1) in the experimental group, porous tantalum tablet was added, while In the control group, porous tantalum tablet was not added. At 5 days after culture, cell growth on the surface of porous tantalum tablet was observed by phalloidin staining. At 1, 3,5, and 7 days after culture, CCK-8 method was used to detect cell proliferation. (2) Group A was added with chondrocyte Inducer; group B with chondrocyte Inducer and bone morphogenetic protein 7; group C with domestic porous tantalum material and chondrocyte Inducer; group D with domestic porous tantalum material and chondrocyte Inducer and bone morphogenetic protein 7. At 7,14 and 21 days after culture, the levels of type II collagen, SRY type high mobility group protein and matrix metalloproteinase-13 secreted by cells In each group was detected by ELISA. Western blot assay was used to detect the expression of type II collagen, SRY type high mobility group protein and matrix metalloproteinase-13. This study was approved by the Animal Experimental Ethics Committee of North China University of Science and Technology. RESULTS AND CONCLUSION: (1) The phalloidin staining results showed that bone marrow mesenchymal stem cells grew well on and around the porous tantalum surface. (2) At 3 and 5 days after culture, the proliferation of bone marrow mesenchymal stem cells was slower In the experimental group than in the control group (P 0.05). (3) At 7,14 and 21 days, the expression of type II collagen and SRY high mobility group protein Increased gradually among groups A, B, C and D (P 0.05). At 21 days, there was no significant difference among groups A, B, C and D (P > 0.05). (4) Western blot assay showed that at 7,14 and 21 days after culture, the expression level of type II collagen and SRY high mobility group protein Increased gradually In groups A, B, C and D (P 0.05). (5) The results showed that bone morphogenetic proteln-7 combined with domestic porous tantalum could Induce cartilage differentiation of bone marrow mesenchymal stem cells, facilitate the expression of type II collagen and SRY high mobility group protein, and Inhibit the expression of matrix metalloproteinase-13.
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Objective To study the effect of basic fibroblast growth factor (bFGF) of different concentrations on phenotypes and dedifferentiation of rabbit chondrocytes in porous tantalum-chondrocyte composites in vitro, so as to provide theoretic basis for cartilage defect repair. Methods The articular chondrocytes from 3-week-old rabbit were cultured and identified by type IT collagen immunocytochemistry and Safranin 0 staining. The 3rd generation chondrocytes were implanted in the porous tantalum and was treated with bFGF of various concentrations. The bFGF-chondrocyte-porous tantalum composites (bFGF compostes) were then divided into 5 groups: group A (1 ng/mL bFGF composites), group B (10 ng/mL bFGF composites), group C (50 ng/mL bFGF composites), group D (chondrocyte-porous tantalum), and group E (pure chondrocyte). The proliferation of chondrocytes was measured by MTT and the cell morphology and growth were observed by scanning electron microscopy (SEM). Phenotypes and dedifferentiation (type I, II, IX, and X collagen) of the chondrocytes were detected by immunocytochemical method. Type II and X collagen mRNA was tested by real-time PCR. Results Type II collagen immunocytochemistry and Safranin 0 staining were positive, confirming that the cultured cells were chondrocytes. MTT results showed that chondrocyte proliferation in groups A, B, C, and D were significantly greater than that in group E CP