Chitosan-film associated with mesenchymal stem cells enhanced regeneration of peripheral nerves: A rat sciatic nerve model

•Chitosan-film and mesenchymal stem cells improved sciatic functional index in transected sciatic nerve in rats.•Chitosan-film and mesenchymal stem cells improved hot plate test in transected sciatic nerve in rats.•Chitosan-film and mesenchymal stem cells improved electrophysiological results in transected sciatic nerve in rats.•Chitosan-film and mesenchymal stem cells improved histomorphometric results in transected sciatic nerve in rats. Peripheral nerve injuries comprise significant portion of the nervous system injuries. Although peripheral nerves show some capacity of regeneration after injury, but the extent of regeneration is not remarkable. Regeneration might be through the activity of the mesenchymal stem cells (MSCs) which can release growth factors or extracellular matrix components or by the therapeutic effect of some material with the MSCs. The present study aimed to evaluate the regeneration of transected sciatic nerve by a therapeutic value of mesenchymal stem cells (MSCs) associated with chitosan-film (Cs) in rat. Male Wistar rats (n=42, 180-200g) were randomly divided into intact; control; sham; Cs; MSCs; MSCs + Cs groups. Functional recovery was evaluated at 2, 4, 6 and 8 weeks after surgery using sciatic functional index (SFI), hot water paw immersion test, electrophysiological, histological analyses. The rats in the MSCs+Cs group showed significant decrease in SFI and hot water paw immersion test during the 2nd to 8th weeks after surgery. Electrophysiological findings showed a significant decrease in latency time in the MSCs +Cs group. Amplitude of the nerve impulses also increased. Number of nerve fibers with more than 6 μm diameters increased significantly in MSCs+Cs. The number of nerve fibers with less than 4 μm diameters also increased significantly in MSCs+Cs group. Taken together, mesenchymal stem cells associated with Cs could improve functional and histomorphological properties of the sciatic nerve after injury which may have some clinical outcomes as well.