诱导后自体骨髓基质细胞移植修复兔关节软骨缺损

Repair of articular cartilage by using induced autogeneic mesenchymal cells derived from bone marrow in rabbits

目的采用经诱导的兔自体骨髓基质细胞移植于受损关节软骨组织进行修复，并对其组织形态学进行观察。方法取新西兰兔髂棘骨髓，分离基质细胞，以含碱性成纤维生长因子 (basic fibroblast growth factor, bFGF,25 ng/ml)及转化生长因子 (transforming growth factor beta 1, TGF-β 1,2 ng/ml)的无血清培养液作诱导培养。采用明胶海绵为载体，实验组用诱导培养后的骨髓基质细胞移植修复兔自体股骨髁关节面的缺损；对照组仅进行单纯明胶海绵移植。结果诱导后的骨髓基质细胞，通过 RT- PCR检测证实有Ⅱ型前胶原 mRNA表达。移植 24周后，肉眼下实验组移植物与正常软骨组织难以区分，表面光滑。而对照组移植物在 24周后为白色松软的组织。光镜下，实验组移植 4周后新生的软骨组织即充填于软骨缺损区，甲苯胺蓝异染性明显， 12周时修复组织逐渐塑形， 24周后修复组织塑形成类似周围正常的软骨组织结构；对照组关节缺损区在各阶段无明显关节软骨修复， 24周后关节缺损区被纤维软骨样组织充填，甲苯胺蓝异染性不明显。结论经诱导后自体骨髓基质细胞移植于受损关节软骨，可促进软骨缺损的快速修复，恢复软骨组织的结构和功能。

Objective To observe the tissus implanted into the damaged articular cartilage of rabbits with induced autogeneic mesenchymal cells. Methods The autologous mesenchymal cells derived from bone marrow of New Zealand rabbits were harvested. With basic fibroblast growth factor(bFGF， 25 ng/ml) and transforming growth factor beta 1(TGF-β 1， 2 ng/ml)， the cells were induced and expanded in cell culture. The induced cells with absorbable gelatin sponge as a carrier were then implanted into the damaged articular cartilage in rabbits as experimental group. The absorbable gelatin sponge without cells were served as control. Specimens were harvested at the end of 4, 12 and 24 week after implantation, and were stained with toluidine blue. Results By RT- PCR, it was confirmed that there was expression of typeⅡ procollagen mRNA in the induced mesenchymal cell. After implantation, it was difficult to macroscopically distinguish the repaired tissues from the normal cartilaginous tissue in the experimental group in 24 weeks. While the defect of articular cartilage was filled with white and swampy tissue in the control group at the same time. Histologically, the defective area of the articular cartilage was replaced by the formation of neo- cartilage which showed positive staining of toluidine blue in 4 weeks in the experimental group. The neo- cartilage was modeled to normal cartilage tissues in 12 weeks and was similar to the surrounding cartilage in 24 weeks. But in the control group, the defect of articular cartilage was not repaired by cartilage tissue at every stage and were replaced by fibrocartilage which was shown weakly positive staining of toluidine blue in 24 weeks. Conclusion The transplant of the induced autogeneic mesenchymal cells derived from bone marrow might promote repair of articular cartilage, and restore its structure and function.