Preliminary Experimental Study Of Brid Ging Peripheral Nerve Defect With Biodegradable PDLLA/NGF Compound Conduit

Objective To establish an animal model for repairing sciatic nerve defect with biodegradable PDLLA/NGF compound conduit in rats and to observe the effect of the conduit on improving sciatic nerve regeneration .Methods 60 Sprague-Dawley rats were randomly assigned into four groups: autograft(group A, n=15), PDLLA conduit(group B, n=15), PDLLA with NGF injected into conduit(group C, n=15), and PDLLA/NGF compound conduit(group D,n=15). Each rat underwent right sciatic nerve transection and kept a 10mm nerve defect, and then repaired according to the above four experimental groups. The process of peripheral nerve regeneration was evaluated at 1,2,3 months following operation by using gross observation, resumption rates of triceps weight, electrophysiological, histological and axon morphologic assessment of the outcomeof nerve regeneration in each rat. 5 rats were checked and measured in every groups at 1,2,3 months after operation respectively.Results All rats survived well besides one rat of group B. There were no necrosis and ulceration in hindlimb of the experimental lateral. Group A was the best in resumption rates of triceps weight at every time site, and then was group D, group C, and group B in turn. There were no significant difference between group A and group D in nerve conduct velocity (NCV) and their NCV were faster than that of group C and group B. Regenerated nerve fibers of the PDLLA/NGF compound conduit group was comparable with that seen in autograft and significantly superior to that of other two groups in histological and axon morphologic index. There were no apparent inflammations around conduits.Conclusions The biodegradable PDLLA/NGF compound conduit had favorable compatibility with rat tissue and it could effectively promote nerve regeneration after bridging sciatic nerve defect of rats. The effect was as good as that of autograft. PDLLA/NGF compound conduit was a potential ideal conduit. We hope it will be applied to clinic with farther study to relieve pains of patients.