种植神经干细胞-许旺细胞的共聚物支架移植修复大鼠损伤脊髓

背景：前期实验显示,在体外乙交酯-丙交酯共聚物支架与神经干细胞和许旺细胞有良好的相容性。目的：观察与许旺细胞共移植,神经干细胞是否能在乙交酯-丙交酯共聚物取向支架内存活、分化,乙交酯-丙交酯共聚物组织工程复合物是否能促进轴突再生及其髓鞘化。方法：制作成年Wistar大鼠T8段半横断脊髓损伤模型,随机分为3组：支架组植入乙交酯-丙交酯共聚物支架,神经干细胞组植入接种神经干细胞（标记绿色荧光蛋白）的乙交酯-丙交酯共聚物取向支架,联合组植入接种神经干细胞（标记绿色荧光蛋白）和许旺细胞的乙交酯-丙交酯共聚物取向支架。结果与结论：移植的神经干细胞可在大鼠脊髓内存活,并迁移至邻近脊髓,联合组标记绿色荧光蛋白阳性细胞存活率显著高于神经干细胞组（P〈0.001）。联合组胶质纤维酸性蛋白/标记绿色荧光蛋白双阳性细胞多于神经元特异性烯醇化酶/标记绿色荧光蛋白双阳性细胞,神经干细胞组未发现神经元特异性烯醇化酶/标记绿色荧光蛋白双阳性细胞。联合组有少部分绿色荧光蛋白阳性细胞表达突触素,再生轴突和有髓轴突数量高于其他两组,但差异无显著性意义（P=0.058）。表明与许旺细胞共移植,可促进神经干细胞向神经元样细胞分化,少部分神经元样细胞还可能形成了突触连接;种植了神经干细胞和许旺细胞的乙交酯-丙交酯共聚物支架可促进轴突再生及其髓鞘化。

Transplantation of copolymer scaffolds inoculated with neural stem cells and Schwann cells for repairing spinal cord injuries in rats

BACKGROUND： Previous studies have shown that poly （lactide-co-glycolide） scaffolds can exhibit good biocompatibility with neural stem cells and Schwann cells in vitro. OBJECTIVE： To investigate whether cografted with Schwann cells, neural stem cells can survive and differentiate in poly （lactide-co-glycolide） scaffold, and whether poly （lactide-co-glycolide） tissue-engineering complexes can promote axonal regeneration and myelinization. METHODS： A Wistar rat model of spinal cord injury with hemisection at T~ segment was established. The rats were divided into three groups randomly： scaffold group, neural stem cells group and co-graft group. Rats in the scaffold group were implanted with poly （lactide-co-glycolide） scaffold; those in the neural stem cells group were implanted with the PLGA scaffolds inoculated with neural stem cells （labeled with green fluorescence protein）; while those in the co-graft group were implanted with PLGA scaffolds inoculated with neural stem cells （labeled with green fluorescence protein） and Schwann cells. RESULTS AND CONCLUSION： Transplanted neural stem cells could survive in the injured spinal cord of rats and migrate near to the spinal cord. Survival rate of positive cells labeled with green fluorescence protein of the co-graft group was significantly higher than that in the neural stem cells group （P 〈 0.001）. In the co-graft group, glial fibrillary acidic protein/green fluorescence protein double-positive cells were more than neuronspecific enolase/green fluorescence protein double-positive cells. However, no neuronspecific enolase/green fluorescence protein double-positive cells could be found in the neural stem cells group. In the co-graft group, only a little part of green fluorescence protein positive cells expressed synaptophysin. Compared to the other two groups, there was a remarkable increase in the number of regenerated and myelinated axons in the co-graft group. But there was no significant difference in the number of