脊髓损伤的PLGA低温成形组织工程支架修复

组织工程的迅速兴起给脊髓损伤后的神经功能恢复带来了新的希望,而三维结构组织工程支架成为用组织工程方法治疗脊髓损伤的关键因素。尝试采用PLGA低温成形支架修复脊髓损伤。采用PLGA作为生物支架材料,通过低温快速成形工艺制备脊髓支架,采用雪旺细胞进行细胞培养实验,选用30只SD大鼠分组进行支架修复脊髓损伤的动物实验,并对实验结果进行组织切片和染色表征。对支架的各项性能进行表征后,结果表明支架的平均孔隙率达到87.64%,具有良好的亲水性。支架降解速率表现出前期慢、后期加快的趋势,实验中支架在前16周表现良好的稳定性,从20周起逐步加快。各项性能能满足组织工程脊髓支架的要求。观察显示,雪旺细胞在PLGA支架上生长、增殖情况良好,支架细胞相容性良好,适合细胞黏附和生长。BBB评分显示,实验组大鼠截瘫情况从第4周起有好转迹象,受伤大鼠后肢观察到轻微活动迹象。不同切片染色观察结果表明,该组织工程支架对于脊髓损伤修复均有不同程度的促进,在阻碍胶质癜痕生成、促进神经纤维及髓鞘愈合方面取得不同程度的效果。观察表明,该方法能够在脊髓损伤修复中取得实质性的治疗效果。

Low Temperature Forming Tissue Engineering PLGA Scaffold to Repair Spinal Cord Injury in Rats

With the rapid development of tissue engineering, scaffolds with 3D structures have become one of the key factors for the treatment of the spinal cord injury. In this work the PLGA porous scaffold fabricated with low temperature deposition manufacturing (LDM) technique was tested in rehabilitation of spinal cord injury. In the paper, poly (lactic-co-glycolic acid, PLGA) was selected to fabricate the spinal cord scaffold through LDM technique. The regeneration of spinal cord injury was induced by implanting the PLGA scaffold containing SCs into the transected spinal cords of Sprague Dawley (SD) rats (total 30). The PLGA scaffold was characterized as good porosity of 87.64%, hydrophilicity and considerable biodegradability. The degradation rate showed the trend of slow at the beginning and getting faster at the later period. In the experiment, the scaffolds were steady in the first 16 weeks, and the degradation rate began to be accelerated from the 20^th week. In addition, the effect of PLGA scaffold on the cell proliferation and cytotoxicity was evaluated by culturing Schwann cells (SCs) on the surface of the scaffold, showing that SCs spread and grew well on the PLGA scaffold with good proliferation. The BBB score indicated that paraplegia of the rats improved from the 4^th week, and slightly movement was visible on the posterior limbs of the injured rates. The investigation of section staining showed that the recovery of the spinal cord was considerably improved after implanting with the PLGA scaffold, which indicated that the PLGA scaffold exhibited great potential to be applied in the spinal cord injury. The PLGA porous scaffold fabricated with LDM has material effect in rehabilitation of spinal cord injury.