Cell-seeded porous silk fibroin scaffolds promotes axonal regeneration and myelination in spinal cord injury rats.

Accumulating evidence indicates that a suitable scaffold designed for the spinal cord injury (SCI) was needed to enhance the survival of transplanted Bone mesenchymal stem cells (BMSCs) and to promote nerve regeneration. The current study was aimed to evaluate the effect of the porous silk fibroin scaffold (PSFSs) seeded with BMSCS on nerve regeneration, myelination and functional recovery after SCI. We previously demonstrated that the PSFSs could bridge defected nerve with nerve fibers when applied to the transected spinal cord. And we found that BMSCs were adhered to the scaffold closely and have good biological compatibility with PSFSs. PSFSs seeded with BMSCs exhibited significant improvement in complete transverse thoracic SCI rat models. Flow cytometric assay also indicated that BMSCs grew well and adhered closely to the surface of the scaffold. The Basso-Beattie-Bresnehan (BBB) scores at each time point showed that the hindlimb motor function of each transplant group was also significantly restored. Meanwhile, growth associated protein 43 (GAP-43)marker of damaged axons regeneration and myelin basic protein (MBP) marker of maintaining the myelin structural and functional integrity, all markedly increased in PSFSs seeded with BMSCs models. Together, these results demonstrated that transplantation of PSFSs seeded with BMSCS could promote the nerve regeneration, myelination and functional recovery after SCI.