Chitosan/hBMSC-ECM biomimetic nerve grafts containing orienting microchannels for peripheral nerve regeneration

Bone marrow mesenchymal stem cell extracellular matrix (BMSC-ECM) can promote peripheral nerve regeneration, and microphysical orientation is essential for peripheral nerve regeneration. In this study, human-derived BMSC-ECM (hBMSC-ECM) and microchannels were introduced into chitosan-based nerve grafts (OCS/ECM) to construct dual biomimetic nerve grafts of structure and composition. For comparison, the same procedure was applied to nerve grafts containing only orienting microchannels (OCS) and autogenous nerves. In vitro experiments showed that the prepared grafts had good blood compatibility and no cytotoxicity. In vivo studies demonstrated that OCS/ECM had better histocompatibility than OCS. The introduction of microchannels allowed chitosan nerve grafts to achieve similar repair effects as autologous nerve grafts in the functional recovery of rats with sciatic nerve defects. Further introduction of hBMSC-ECM may result in synergistic effects on structure and composition that could significantly promote the rate of nerve regeneration, myelination, and target muscle recovery. Dual biomimetic nerve grafts are attractive candidates for the treatment of critical nerve defects.