体内构建骨软骨复合体修复骨软骨缺损的实验研究

Experimental study of treating osteochondral defects with osteochondral composites constructed in vivo

[目的]探讨软骨组织工程方法修复骨软骨缺损理想的种子细胞和支架材料。[方法]体外诱导骨髓基质干细胞向软骨细胞定向分化,分别与PLGA支架复合培养,并模仿马赛克骨软骨移植术在犬关节骨软骨缺损深层置入MSC-支架复合体,浅层置入诱导培养后的MSC-支架复合体,紧密压配,体内构建骨软骨复合体,观察其修复的情况。[结果]16周实验组缺损区完全由透明软骨修复,与周围正常软骨完全融合,组织观察显示以软骨细胞修复为主,软骨下骨形成,潮线基本恢复;阴性对照组缺损区主要由纤维组织修复,部分由透明软骨修复,组织观察显示以纤维细胞修复为主,混有部分软骨细胞;空白对照组完全由纤维组织修复。[结论]MSCs经向软骨细胞定向分化后复合PLGA支架材料,通过紧密压配方式与MSCs-PLGA支架在体内构建骨软骨复合体,可以有效修复骨软骨缺损。

[ Objective]To evaluate the effect of treating the osteoehondral defects with implanted cell-scaffold composites, cultured MSCs as seed cells and PLGA as scaffolds,and to acquire desirable seed cells and scaffold materials. [ Method] BMSCs were induced to differenciatiated into ehondroeytes, co-cultured with PLGA scaffold respectively in vitro, then implanted into osteochondral defects on canine models by using techniques of mosaieplasty, induced BMSC-PLGA scaffold composites in the top of the defect and BMSC-PLGA scaffold composites in the bottom of the defect, osteoehondral composites were constructed in vivo, and repair was observed with naked eyes and histology. [ Result] At 16 weeks after transplantation the defects of expeirmental group were covered with semi-transparent smooth white tissue and the margins between the repair tissue and the surrounding cartilage were not recognized. Histologically, most of the repair tissue was consisted with ehondroeytes, maintained their thickness to the full depth of the original defects. The subehondral bone was well remodeled. The tidemark was observed. The defects of positive control group were covered with repair tissues, and partial were conformed with original cartilage. The repair tissue was partly filled with ehondroeytes. However, the defects of negative control group were repaired with soft fibrous tissues without luster, and an obvious boundary between reparative and original cartilage was seen. [ Conclusion ] MSCs-PLGA scaffold composites, constructed into osteochondral composites by suppressing closely in vivo ,are the ideal materials for repairing cartilage defects.