兔骨髓间质干细胞修复肌腱缺损效果观察

目的　观察兔骨髓间质干细胞(MSCs)修复肌腱缺损的效果。　方法　分离培养家兔MSCs,检测CD44mRNA进行鉴定。6只家兔分为实验组和对照组,每组3只。在兔跟腱处造成3cm长的缺损,实验组家兔以自体MSCs为种子细胞、以胶原聚羟基乙酸(PGA)为生物支架构建肌腱并移植于跟腱缺损处,对照组家兔仅以PGA生物支架修复跟腱缺损。于术后4、8、12周对移植部位进行大体和组织学观察。　结果　MSCs培养11d时CD44mRNA显示阳性。实验组术后8周肉眼可见移植处形成腱样组织, 12周时组织学观察可见形态一致、顺应力学方向排列于胶原中的腱样细胞,类似正常肌腱组织。对照组所形成的新生组织较实验组细小且与周围组织粘连, 12周时组织学观察见细胞排列紊乱,胶原纤维呈松散网丝状。　结论　应用组织工程技术以自体MSCs修复肌腱缺损具有可行性。

Repair of rabbit tendon by autologous bone marrow mesenchymal stem cells

Objective To investigate the effect of rabbit bone marrow mesenchymal stem cells (MSCs) as seed cells for the repair of tendon defect. Methods The MSCs were isolated, amplified and identified by detection of surface protein CD44 mRNA. A 3 cm long defect was made in the Achilles tendon of the rabbit. The rabbits were divided into experimental (E) and control (C) groups. The autologous MSCs were implanted into a collagen-polyglycolic acid (PGA) scaffold to form a tissue-engineered tendon, which was then transplanted to bridge the defect in the E group, while only collagen-PGA was transplanted to bridge the defect in the C group. The transplanted tendon was observed grossly and microscopically at 4,8,12 weeks after operation. Results The cultured MSCs exhibited positive staining of CD44 on 11 days after in vitro culture. A tendon-like tissue could be discerned at the operation site in the E group 4 weeks after operation. Tendon-like cells similar to normal tendon tissue,being axially arranged in collagen matching the mechanical direction, with uniform morphology could be seen in E group 12 weeks after operation. The newly regenerated tissue in C group adhered to the adjacent tissue and was smaller than that in E group. The collagen fibers in the regenerated tissue were loose with reticular and filiform structure,and the cells were arranged disorderly 12 weeks after the transplantation. Conclusion It is feasible to repair the tendon defect with autologous MSCs as seed cells.