Functional and Histomorphometric Evaluation of Chitosan/Polyethylene Oxide Biocompatible Scaffolds on Peripheral Nerve Injury Repair and Neoangiogenesis in Wistar Rats

This study aims to examine the effect of the chitosan/polyethylene oxide (Cs/PEO) scaffold on sciatic nerve regeneration and neural tissue angiogenesis in adult male rats. Thirty two rats were divided into normal, control, sham and Cs/PEO groups. In the control, sham and Cs/PEO groups, the sciatic nerve was severed in the middle region of the thigh, and epineuria was sutured. After 8 weeks, the functional recoveries, the nerve conduction velocity (NCV), the nerve fiber number, the largest nerve fiber area (LNFA), the largest axon area (LAA) and the number of blood vessels were evaluated. Nerve fiber numbers showed a statistically significant increase in the Cs/PEO, control and sham relative to the normal group. The mean size of the LAA and blood vessels indicated a significant increase in the Cs/PEO group in comparison with the others and the normal group, respectively. The study demonstrated that nerve regeneration with epineural sutures and Cs/PEO could prevent fatal neuron changes and promote angiogenesis following sciatic nerve injury particularly in the first 2 weeks, which rescue some neurons in this initial vital time of injury. However, the Cs/PEO scaffold alone may not be sufficiently effective in sciatic nerve regeneration over a long time period.