三维取向PLGA神经导管促进坐骨神经再生的实验研究

目的:探讨应用改进静电纺丝技术一次成型制备三维(3D)取向聚乳酸与聚羟基乙酸共聚物(PLGA)纳米神经导管的可行性,检测其对坐骨神经再生的促进作用。方法:应用改进的静电纺丝技术制备无缝取向PLGA纳米神经导管,通过扫描电镜和透射电镜检测支架的纳米结构;分别制备取向和非取向纳米纤维支架修复13mm坐骨神经缺损模型。36只成年SD大鼠随机分为3组(每组12只),A组:非取向PLGA神经导管组(阴性对照);B组:取向PLGA神经导管组,C组:自体神经移植组(阳性对照),于术后3月通过大体观察、行走足印分析、腓肠肌萎缩率、电生理检测、组织形态学检测、透射电镜检测及图像分析,评价无缝取向PLGA纳米神经导管修复坐骨神经缺损的效果。结果:神经导管修复神经缺损三月后,大体观察显示神经导管结构完整,无坍塌和断裂;各组再生神经均有通过神经导管长入远端。B组与C组的腓肠肌萎缩率和神经电传导速度无统计学差异(P0.05),均优于A组。B组与C组再生神经纤维数量及成熟程度均要明显优于A组。结论:无缝取向PLGA纳米神经导管能够诱导并促进神经再生,提高坐骨神经再生的质量,有望成为自体神经移植的替代物。

Highly Aligned Seamless PLGA Nanofiber Conduits for Sciatic Nerve Regeneration

Objective:This study is to explore the feasibility of the improved electrospinning technique prepared uniaxially aligned three-dimension (3D) orientation PLGA nanofiberous conduit and to investigate the effectiveness of such nerve conduits on the peripheral nerve regeneration.Methods:The uniaxially aligned 3D PLGA nanofiberous conduit was made by the improved electrospinning technique. The Nanostructures of the conduit detected by scanning and transmission electron microscope. 36 male adult rats were randomly divided into three groups of 12 rats in each group. A 13mm sciatic nerve defect in the right sciatic nerve was created in the rats and was repaired with non oriented PLGA conduits (group A), with oriented PLGA conduits (group B) and with autograft (group C) respectively. After 3 months postoperatively, the method of the walking footprint analysis, the gastrocnemius muscle atrophy rate, electrophysiological testing, tissue morphology detected, the transmissionelectron microscopy and image analysis are used to evaluate the result of the seamless orientation PLGA nerve conduit on repairing the peripheral nerve defects.Results:There were no collapse and fracture in scaffolds and the conduit can provide ideal mechanical support after three month of the operation. Regenerated nerve through nerve conduit to the distal end of nerve in each group. There were no significant difference between group B and C in the atrophy of gastrocnemius muscle and nerve conduction velocity (P<0.05), and were better than that of group A. The number and the maturity of regernate nerve fiber in group B and C are obviously better than the group A.Conclusion:These uniaxially aligned seamless 3D electrospun PLGA nerve guides can induce and promote nerve regeneration, improve the quality of the sciatic nerve regeneration and so may be a promising substitute for autogenous nerve grafts.