Chitin nerve conduits with three-dimensional spheroids of mesenchymal stem cells from sd rats promote peripheral nerve regeneration

Abstract

Peripheral nerve injury (PNI) is an unresolved medical problem with limited therapeutic effects. Epineurium neurorrhaphy is an important method for the treatment of PNI in clinical application, but it is accompanied by inevitable complications such as the misconnection of nerve fibers and neuroma formation. Conduits small gap tubulization has been proved to be an effective suture method to replace the epineurium neurorrhaphy. In this study, a chitin conduit was used to bridge the peripheral nerve stumps. The micromorphology, mechanical property, and biocompatibility of chitin conduits were characterized. The results showed chitin was a high-quality biological material for constructing nerve conduits. In addition, previous reports demonstrated that mesenchymal stem cells culture as spheroids can improve the therapeutic potential. In the present study, we used a hanging drop protocol to prepare bone mesenchymal stem cells (BMSCs) spheroids. Meanwhile, spherical stem cells could express higher stemness-related genes. In the PNI rat models with small gap tubulization, the transformation of BMSCs spheroids, but not BMSCs monolayer, improved sciatic nerve regeneration. Therefore, combining BMSCs spheroids with chitin nerve conduits shows application potential in promoting peripheral nerve regeneration.