PDLLA／NGF复合导管促进周围神经缺损再生的形态学研究

目的探究聚d,L-乳酸,神经生长因子(PDLLA/NGF)可吸收性复合导管桥接对大鼠坐骨神经缺损再生修复的促进作用,为临床上周围神经损伤再生修复提供实验依据。方法60只SD大鼠随机均分4组:自体神经移植(A组),单纯PDLLA导管(B组),PDLLA加一次性给NGF(C组),复合导管(D组)。制作坐骨神经10 mm缺损,按上述分组桥接,手术后1、2、3月每组各取5只修复处组织。行大体观察、三头肌湿重、光镜观察与图像处理、电镜超微结构观察。结果同时间段组间比较,三头肌恢复率A组高,D组次之,C组较差,B组最差(P<0.05)。组织学观察及图像分析显示,D组再生神经的数、质量都显著优于B、C组(P<0.05),接近A组。电镜观察显示A、D组中段神经纤维密度大、直径大、髓鞘厚,内有发育良好的神经丝和微管。B、C组神经稀、直径小、髓鞘薄、无髓神经相对多。结论PDLLA/NGF复合导管具有良好的组织相容性。用该管桥接修复大鼠受损的坐骨神经,能有效地促进其再生。

Morphological Study of Peripheral nerve Regeneration Promoted by PDLLA/NGF Compound Conduit

Objective To explore the promotive effect of biodegradable poly d, 1-lactic acid / nerve growth factor ( PDLLA/ NGF ) compound conduit on the regeneration of the injured sciatic nerve. Methods Sixty Sprague-Dawley rats randomly were averagely divided into four groups, i.e. autograft (group A), PDLLA conduit (group B), PDLLA and only one injection of NGF into conduit (group C), and PDLLA / NGF compound conduit (group D) groups. Each rat underwent right sciatic nerve transection and left a 10 mm nerve defect, and then were treated respectively according to the above-mentioned four experimental groups. The morphologic assessment of nerve regeneration was done by gross observation, resumption rates of triceps weight, histological and ultrastructural observation respectively at 1, 2, 3 months after the operation. Results There were no necrosis and ulceration in the experimental hindlimbs of all the rats. The best resumption rates of triceps weight after the operation was group A, and then was groups D, C and B in turn (P< 0.05). The regenerated nerve fibers of group D were similar to that of group A and significantly superior to that of groups B and C in the histological and ultrastructural morphology (P<0.05). The neurofibrillae, in which there were well developed neurofilaments and microtubules, were more dense, bigger in diameter and had thicker myelin sheaths in groups A and D than that in groups B and C. Conclusions The biodegradable PDLLA / NGF compound conduit, which has favorable compatibility with the tissues in the rats and can effectively promote injured peripheral nerves regeneration in rats, should be a potential ideal bridging material of the injured peripheral nerves.