Chitosan/PVA nerve conduits repair sciatic nerve defect in rats

Abstract

Objective To investigate the effects of chitosan/PVA nerve conduits which used for re- pairing sciatics nerve defect in rats. Methods Twenty-seven rats were divided into 3 groups randomly, with 9 rats in each group. Firstly, the 15mm defects in the left sciatic nerves were made in the rats and were respectively repaired with ehitosan/PVA conduits graft （group A）, the silicon conduits graft （group B）, and autografts （group C）. At 12 weeks after the operations, the left sciatic nerves were taken out, and the com- parative evaluation was made on the repairing effects by wet weight of gastrocnemius and soleus muscles, histo- logical examination, computerized imaging analysis and True Blue retrograde tracing. Results The wet weight of gastrocnemius and soleus muscles showed no significant difference between the chitosan/PVA graft and autograft groups （P 〉 0.05）. The wet weight of gastrocnemius and soleus muscles in significant difference between the chitosan/PVA graft and the silicon group at 12 weeks after the operation（P 〈 0.05）. The nerve fiber density showed no statistically significant differences between the ehitosan/PVA and autograft groups （P 〉 0.05）. The regenerative nerve fiber in group B had normal morphological and structural characters under transmission electron microscope. True Blue-labeled neuron cell bodies were found within both anterior horn of gray matter in the spinal cord and dorsal root ganglions （DRGs） ipsilateral to the operated side of the test- ed rats on illumination with ultra-violet light 1 week after the injection of True Blue. Conclusion Chi- tosan/PVA nerve conduit can effectively promote the nerve regeneration and myelinization of rat sciatic nerve, which is expected to substitute for autograft to repair nerve defects suceesfully. Key words: Sciatics nerve; Nerve regeneration; Nerve guidance conduits; Chitosan/PVA