三维动态诱导对自体组织工程软骨远期退变抑制效应的实验研究

目的体外诱导自体骨髓间充质干细胞（aMSC）向软骨细胞分化,验证三维动态诱导培养的软骨分化效率和远期修复效应。方法分离培养多样本aMSC,分别行转壁生物反应器内三维动态诱导（三维动态诱导组）培养和常规二维平面诱导（二维平面诱导组）培养,比较各自的软骨分化效率;收获细胞与注射型蛋白胶混合,修复动物关节软骨缺损。8、12、24、48周后分别取材,观察大体形态和组织学形态,进行组织学评分,比较长期修复效果。结果二维平面诱导时仅出现局部蛋白多糖沉积,只少数细胞表达Ⅱ型胶原;三维动态诱导培养时蛋白多糖沉积明显并广泛表达Ⅱ型胶原,其胶原产量和蛋白多糖含量明显高于二维平面诱导组。在体内实验中,三维动态诱导组：8、12周后缺损完全修复,表面光滑,质地坚硬,与周围软骨紧密结合,组织学表现为类透明软骨结构,24、48周后修复组织与周围界限消失,仍保持类透明软骨的结构。二维平面诱导组：8周后软骨缺损即可被类透明软骨修复,但12周后即开始出现退变,24周后退化明显,软骨组织骨化变薄,48周后则大部分骨性退化,表层残留菲薄纤维组织。结论三维动态诱导培养可提高aMSC的软骨分化效率和远期修复效果,可为深化自体软骨组织工程研究提出新思路。

Three dimensional induction of autologous mesenchymal stem cell and the effects on depressing long-term degeneration of tissue-engineering cartilage

OBJECTIVES: To induce autologous bone marrow derived mesenchymal stem cell (aMSC) into chondrocyte, and to confirm the effects of 3 dimensional (3D) dynamic inducing in vitro and their long-term animal model repairing in vivo. METHODS: aMSC were seperated from rabbits bone marrow aspirates, then respectively experienced 3D dynamic inducing in alginate drops in modified rotating wall bioreactor culture or in two dimensional (2D) inducing (culture flask) for 10 d. The induced cells were harvest and then mixed with fibrin sealant (FS) to repair rabbit knee femoral trochlea cartilage defects model. After 8, 12, 24, 48 weeks animals were euthanized. Gross appearance, histological appearances were examined. RESULTS: Flask culture groups showed a little chondrocyte differentiation, 3D inducing group showed obviously chondrocyte differentiation, improved collagen II and proteoglycan production. For 3D inducing ones in vivo, the cartilage defects were smoothly repaired by white translucent hard tissue with obvious hyaline-like cartilage histological appearance after 8, 12 weeks, and the defects boundary were hard to be identified with hyaline like cartilage with sustained histological appearance and score after 24, 48 weeks. For 2D ones in vivo, the cartilage defects were smoothly repaired after 8 weeks by hyaline like cartilage which showed accelerated degeneration after 24 weeks and lose cartilage performance completely after 48 weeks. CONCLUSIONS: 3D dynamic inducing may assist aMSC on differentiating into chondrocyte, improve its long-term in vivo repairing effects, and enlighten its further applications in tissue engineering cartilage.