转化生长因子β1缓释载体诱导骨髓基质干细胞成软骨分化

目的探讨转化生长因子β1（TGF—β1）缓释对骨髓基质干细胞诱导成软骨分化的影响。方法乳化交联法制备TGF—β1壳聚糖缓释微球并将其与壳聚糖支架复合，将骨髓基质干细胞置于复合载体中立体培养，通过HE染色、Ⅱ型胶原免疫组化染色、扫描电镜观察复合载体对细胞的增殖、分化及功能的影响。结果骨髓基质干细胞于复合载体中培养，细胞形态类似软骨细胞，并可见细胞增殖及细胞外基质分泌，Ⅱ型胶原免疫组织化学染色示基质中有Ⅱ型胶原表达，其细胞增殖率及Ⅱ型胶原分泌功能均较对照组明显增强。结论复合载体能够控制TGF-β1的释放并保持其活性，可促进骨髓基质干细胞的增殖并诱导其向软骨细胞分化。

Effect of controlled TGF-β1 release on chondrogenic differentiation of human bone mesenchymal stem cells in vitro

Objective To establish and evaluate a novel system, chitosan scaffolds incorporated with chitosan microspheres loaded with TGF-β1, for inducing chondrogenic differetiation of human bone mesen- chymal stem cells （BMSCs）. Methods Chitosan scaffolds and chitosan microspheres loaded with TGF-β1 were prepared by the freeze-drying and the emulsion-crosslinking method respectively. The BMSCs were seeded on the scaffolds containing TGF-β1 microspheres and incubated in vitro for 3 weeks. Histological examination and type Ⅱ collagen immunohistochemical staining was performed to evaluate the effects of released TGF - β 1 on cell proliferation , differentiation and synthesis of the extracellular matrix . Results BMSCs attached to the TGF-β1 microsphere incorporated scaffolds had largely changed to chondrocyte-like morphology and could proliferate and secrete the matrix on the porous scaffolds. Type Ⅱ collagen revealed by immunostaining was most pronounced in the cells cultured in the TGF-β1 mierosphere incorporated scaf- folds, whereas in control group the staining was slightly positive. Both proliferation rate and production of extraeellular matrix were significantly higher in the TGF-β1 microsphere incorporated scaffolds than in the control scaffolds. Conclusions TGF-β1 mierosphere incorporated scaffolds can serve as delivery vehicles for controlled release of TGF-β1, augment proliferation of BMSCs, and induce chondrogenic differetiation of human BMSCs.