Experimental study of bridging peripheral nerve defect with biodegradable PDLLA/NGF controlled release conduit

Objective: To evaluate the effect of the controlled release conduit of biodegradable poly D, L-lactic acid nerve growth factor(PDLLA/NGF) on bridging peripheral nerve defect. Methods: Sixty Sprague-Dawley rats were randomly divided 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 controlled release conduit(group D, n =15). Each rat underwent right sciatic nerve transection with 10 mm nerve defect, then these defects were repaired in the four different experimental groups. The process of the peripheral nerve regeneration was evaluated at 1,2,3 months following operation and the items evaluated were gross observation, triceps weight, electrophysiological, histological and axon morphologic assessment of the outcome of nerve regeneration. Results: Nerve regeneration in group D was comparable with that seen in group A and was significantly superior to that in other two groups in electrophysiological, histological and axon morphologic index. Conclusions: PDLLA/NGF controlled release conduit was a potential ideal conduit that can effectively promote nerve regeneration after bridging sciatic nerve defect of rats. The effect was as good as that of autograft.