联合应用成骨诱导后骨髓间充质干细胞与PLGA支架材料修复兔桡骨缺损的实验研究

目的研究聚乳酸聚乙醇酸复合物（ Po （ yclactic - co - glycolic acid ）, PLGA ）支架作为组织工程骨支架修复骨缺损的可行性。方法体外培养兔骨髓间充质干细胞（bone marrow stromal cells, BMSCs），在成骨诱导荆地塞米松等的诱导下，向成骨细胞转化，并使之与修饰后PLGA支架复合，植入兔桡骨缺损模型，作为实验组。对照组a为PLGA材料对照，对照组b为空白对照，通过影像学观察骨缺损的修复情况。结果地塞米松等诱导组细胞形态向类成骨细胞转化，碱性磷酸酶表达明显增高，并表达I型胶原。应用多聚赖氨酸修饰的PLGA与成骨诱导的BMSCs复合植入骨缺损后，与对照组相比影像学显示明显促进骨缺损的愈合。结论适当浓度成骨诱导剂可成功的将免骨髓间充质细胞向成骨细胞诱导，诱导后细胞与PLGA支架联合应用可较好修复兔桡骨缺损。

Experimental Study on Repairing Segmental Radius Defects of Rabbit with Induced Osteoblasts Coculture with Poly （lactic -co -glycolic acid）

Objective To investigate the feasibility of PLGA as scaffold material in bone tissue engineering. Methods The puri- fied bone marrow stromal cells which were separated from rabbit were induced into osteoblasts by Dexamethasone, β - glycerophophate and Vitamin C and co - cultured with modified PLGA in vitro, then implanted them into the defects of rabbits as the experiment group, in the control group A, only PLGA was implanted, in control group B, nothing was implanted. The results were evaluated by radiograph. Results The form of the induced ceils by Dexamethasone was converted to like - osteoblasts, the expression of ALP increased noticeably, and the expression of Collagen I was observed. In the experiment group, 12 weeks after the operation, the defect was repaired by newly - formed callus. In the two control groups, after 12 weeks no callus formed and the defects were not repaired. Conclusions Rabbit bone marrow stromal cells can be induced into marrow stromal osteoblasts by suitable contents of dexamethasone. Modified PLGA is a good scaffold material for the bone tissue engineering.