Background and purpose: The aim of this study was to determine the effects of chitosan/polyethylene oxide (Cs/PEO) scaffold and human mesenchymal stem cells derived from Wharton’s jelly (WJ-hMSCs) on regeneration of the sciatic nerve injury in rats.

Materials and methods: In this research, 42 adult male rats were divided into six groups. 1-Normal (intact) group: healthy rats without any nerve transection; 2- Control group: sciatic nerve was cut and sutured; 3- Sham group: culture medium was injected; 4- Cs/PEO group: scaffold with a thin Cs/PEO was used around the injury site; 5- WJ-hMSC group: WJ-hMSCs injected around the site of injury, and 6- WJ-hMSCs-Cs/PEO group: WJ-hMSCs were seeded on Cs/PEO membrane and used around the injury site.  Behavioral assessments were done at 2, 4, 6 and 8 weeks following the surgery. Histological evaluation was performed at the end of the study.

Results: Our results showed that behavioral values in experimental groups significantly increased when compared to intact group (P<0.05). These values in WJ-hMSC-Cs/PEO group significantly improved compared to the control and sham groups (P<0.05). In addition, histological findings revealed significant increase in the number of nerve fibers in experimental groups compared to intact group (P<0.05). Histological results revealed improvements in groups 4, 5 and 6, however, there was no significant difference between these groups and sham or control group.

Conclusion: This study showed the positive effects of chitosan/polyethylene oxide scaffold and human mesenchymal stem cells derived from Wharton’s jelly on nerve regeneration of transected sciatic nerve in rat model.