NGF／PLGA复合神经导管修复大鼠周围神经缺损的实验研究

目的：应用神经生长因子（NGV）、聚乳酸和聚羟基乙酸的共聚物（PLGA）和牛血清白蛋白（BSA）制成NGF／PLGA复合神经导管。检测其综合性能和了解其修复大鼠周围神经缺损的可能性。方法：体外模拟体内环境，检测它的降解时间及用ELISA的方法来检测NGF的释放情况；手术造成大鼠坐骨神经约10mm的缺损，分别采用自体神经移植（A组）、NGF／PLGA复合神经导管桥接（B组）和单纯PLGA导管（C组）桥接，术后4、8、12周进行大体观察、神经电生理测定、HE染色、变色酸2R一亮绿髓鞘染色、电镜观察和图像分析对比。结果：在体外NGF／PLGA复合神经导管能在体外释放NGF约18天，约在14周左右导管降解完毕。NGF／PLGA神经导管组在促进坐骨神经再生、再生神经纤维排列规律化、提高再生神经髓鞘化、加速再生神经功能重建等方面均优于单纯PLGA导管组。比自体神经移植组略差。结论：NGF，PLGA复合神经导管具有良好的组织相容性，对大鼠坐骨神经缺损具有良好的桥梁作用和促神经生长的作用，效果接近自体神经移植。

Experimental study on NGF/PLGA nerve guide conduits promoting peripheral nerve regeneration in rats

Objective:To investigate degradation behaviors,the amount of NGF released in vitro and the effect of NGF/PLGA nerve guide conduits on regeneration of the peripheral nerve defects in vivo. Method:The degradation test was performed by weight loss measurements in phosphate-buffered saline(PBS)and the amount of NGF released by the nerve guide conduits was quantified by ELISA analysis in vitro. A 10 mm defect was produced in the left sciatic nerve of each rat. Autograft,NGF/PLGA nerve guide conduits and PLGA nerve guide conduits were used to bridge the nerve defects. Pathological examination, neural electrophysiological examination and computerized imaging analysis were carried out at week 4,8,12 postoperation. Result:In vitro,NGF can't be detected by ELISA after 18 days and the nerve guide conduits were fully degraded after about 13 weeks. In vivo ,the number of nerve regeneration,nerve fibers arrangement,myelination and nerve function reconstruction in NGF/PLGA nerve guide conduits were better than those in PLGA nerve guide conduits.Conclusion:NGF/PLGA compound guide conduits can effectively promote peripheral nerve regeneration.