骨髓间质干细胞体外预构组织工程化肌腱的实验研究

目的探讨骨髓间质干细胞与胶原-聚羟基乙酸的细胞相容性,为构建组织工程化肌腱寻求理想方法.方法以贴壁法分离、培养骨髓间质干细胞,并检测CD44.在实验组中将骨髓间质干细胞置入含胶原-聚羟基乙酸的DMEM培基中培养:在对照组中将骨髓间质干细胞置入DMEM培基中培养.通过MTT方法比较两组的细胞活性和生长情况,并对实验组进行超微观察.以骨髓间质干细胞为种子细胞,以胶原-聚羟基乙酸为支架在体外预构组织工程化肌腱.结果以贴壁法原代培养骨髓间质干细胞,11天细胞即汇合成片,检测CD44示阳性.骨髓间质干细胞接种于胶原-聚羟基乙酸中混合培养后14天生长良好,始终保持89%以上的细胞活力,与对照组比较无显著差别;实验组细胞数未发生明显改变,而对照组从第4天开始即发生增殖.透射电镜示实验组细胞培养14天后仍保持旺盛的分泌功能.体外预构的组织工程化肌腱具有良好的形态,细胞伸展成梭形,沿聚羟基乙酸缝线大致平行排列.结论骨髓间质干细胞与胶原-聚羟基乙酸的细胞相容性好.以骨髓间质干细胞为种子细胞,以胶原-聚羟基乙酸为支架可在体外初步预构组织工程化肌腱.

Fabrication of a tissue-engineered tendon in vitro

Objective: To investigate the cytocompatibility of collagen-polyglicolic acid (PGA) combined with bone marrow mesenchymal stem cells (MSCs) in tendon tissue engineering. Methods: The bone marrow mesenchymal stem cells were isolated and amplified. Their marked surface protein CD44 was detected through in situ hybridzation. In the experimental group the mesenchymal stem cells were cultured in DMEM which contained type I collagen and PGA suture; while in the control group the cells were cultured in pure DMEM. Their growth was observed under microscope, electron microscope and MTT criteria. A tissue-engineered tendon was pre-fabricate using mesenchymal stem cells as seed cells and collagen-PGA as scaffold in vitro. Results: For their characteristic of attaching to plate, the primary generation bone marrow mesenchymal stem cells can be isolated and flocked together after being cultured 11 days later. The third generation cells showed positive staining of CD44. During the two weeks of culture the MSCs kept their abilities of secretion and over 89% of vitalities which were similar to the control group. But there was no evidence of proliferation in the experimental group, while the cells in the control group began to proliferate 4 days later. The pre-fabricated tissue-engineered tendon had a good shape with the cells well-spread and parallel-arranged around the PGA suture. Conclusions: The results show that collagen-PGA has a good cytocompatibility with MSCs. It is possible to fabricate a tissue-engineered tendon in vitro using MSCs as seed cells and collagen-PGA as scaffold.