可降解聚乳酸导管与骨髓基质干细胞源性许旺细胞构建组织工程化神经

背景:许旺细胞是周围神经系统中惟一的神经胶质细胞,在周围神经再生中有重要的作用,但其存在增殖能力差,需要异体取材,体外培养困难和活性下降等缺点.目的:分析利用人骨髓基质干细胞经诱导分化为许旺细胞构建组织工程化神经修复神经缺损的可能性.设计、时间及地点:随机分组设计、动物对照观察,2004-03/2005-04在黑龙江省兽医药研究所完成.材料:8周龄雌性Wistar大鼠24只.建立10 mm坐骨神经缺损的动物模型.方法:24只大鼠按随机数字表法分为3组,组织工程化神经移植组、单纯聚乳酸导管移植组、自体神经移植组,每组8只.组织工程化神经移植组:经诱导骨髓基质干细胞分化许旺细胞与天然细胞外基质凝胶及可降解聚乳酸导管构建组织工程化神经桥接神经缺损;单纯聚乳酸导管移植组;单纯将细胞外基质凝胶注入可降解聚乳酸导管桥接神经缺损:自体神经移植组:将截取的10 mm神经旋转180°后,行断端吻合.主要观察指标:移植后12周进行神经电生理、新生神经组织学观察和轴突计数等检测坐骨神经功能恢复情况.结果:诱导后成人骨髓基质干细胞具有许旺细胞形态及特性.移植后12周,再生神经已通过缺损区长至远端.组织工程化神经移植组、自体神经移植组各项检测指标均优于单纯聚乳酸导管移植组(P<0.05),组织工程化神经移植组、自体神经移植组差异无显著性意义(P>0.05);组织工程化神经移植组、自体神经移植组聚乳酸导管降解吸收明显.结论:人骨髓基质干细胞在体外可诱导分化为许旺细胞,利用其与细胞外基质及可降解聚乳酸导管构建组织工程化神经可修复周围神经缺损.

Construction of tissue-engineered nerves with degradable polylactic acid tube and Schwann cells derived from bone marrow stromal stem cells

BACKGROUND: Schwann cells are the only glial cells in the peripheral nervous system and play an important role in the regeneration of peripheral nerves, while they have poor proliferation capacity and decreased activity, need allografts, and are difficult to culture in vitro. OBJECTIVE: To analyze the feasibility of repairing neurologic defects with tissue-engineered nerves constructed with Schwann cells derived from bone marrow stromal stem cells. DESIGN, TIME AND SETTING: Randomized controlled observation was conducted at Heilongiiang Institute of Veterinary Pharmaceutics between March 2004 and April 2005.MATERIALS: Twenty-four 8-weck-old female Wistar rats were used to establish animal models with 10 nun defect of sciatic nerve. METHODS: Twenty-four rats were divided into 3 groups by random digits table, tissue-engineered nerve group, polylactic acid robe group and autologons nerve group, with 8 rats in each group. Tissue-engineered nerve group: tissue-engineered nerve Was used to bridge neurologic defect, which was constructed with Schwann cells derived from bone marrow stromal stem cells, natural extracelhilar matrix gel and degradable polylactic acid tube. Polylactic acid robe group: injecting extracellular matrix gel into degradable polylactic acid tube to bridge neurologic defect. Autologous nerve group: 10 mm of nerve was cut and performed end-to-end anastomosis after revolving 180 degrees. MAIN OUTCOME MEASURES: Functional recovery of sciatic nerve was detected with electrophysiological observation of nerve, and histological observation and axon count of the newly generated nerve tissue at 12 weeks after transplantation. RESULTS: After introduction, adult bone marrow stromal stem cells had the morphology and properties of Schwann cells. The regenerated nerve had grown to the distal end passing through the defect at 12 weeks after transplantation. The detection indexes in the tissue-engineered nerve group and autologous nerve group were better than that in the polylactic acid tube group (P < 0.05), there were no significant differences between the tissue-engineered nerve group and autoiogous nerve group (P < 0.05); The degradation and absorption of polylactic acid tube were obvious in the tissue-engineered nerve group and autologous nerve group. CONCLUSION: Human bone marrow stromal stem cells can be induced to differentiate into Schwann cells in vitro, and tissue-engineered nerve constructed with Schwann cells, extracellular matrix and degradable polylactic acid tube can repair peripheral neurologic defect.