Sandwich-Layered Structure Nanofiber Conduits Facilitating the Repair of Long-Gap Nerve Defects

This study evaluated the efficacy of electrospun nanofiber conduits in facilitating the repair of sciatic nerve injuries in rats. Gelatin/polycaprolactone-blended nanofiber membranes and "sandwich"-layered nanofiber conduits were prepared using electrospinning techniques and assessed through in vitro cellular and in vivo animal experiments. The in vitro experiments demonstrated that the prepared nanofiber membranes supported the proliferation of rat bone marrow mesenchymal stem cells and promoted the axonal growth of dorsal root ganglion neurons. The in vivo results indicated that the "sandwich"-layered nanofiber conduits had a higher sciatic functional index at 3 months post surgery than the blended nanofiber membrane group and exhibited better nerve regeneration outcomes in histological examinations. Additionally, immunofluorescence staining results suggested that the "sandwich"-layered nanofiber conduits tended to stimulate macrophage polarization toward the M2 phenotype, potentially aiding in the nerve repair process. The findings suggest that the prepared nanofiber conduits have promising application potential as alternatives to autologous nerve grafts for the treatment of peripheral nerve defects.