Biomimetic Electrospun PLLA/PPSB Nanofibrous Scaffold Combined with Human Neural Stem Cells for Spinal Cord Injury Repair

Abstract

Spinal cord injury (SCI) treatment remains a worldwide challenge considering its limited self-repair capacity. The transplantation of neural stem cells (NSCs) has been proposed as a potential approach to restoring neurological function by promoting axonal regeneration. While nanofibrous biomaterials provide the biomimetic microenvironment for the immobilization and growth of transplanted NSCs. In this study, a biomimetic poly(polyol sebacate)-based elastomeric nanofibrous scaffold developed with poly(l-lactic acid) (PLLA) and poly(polycaprolactone triol-co-sebacic acid-co-BES sodium salt) (PPSB) was fabricated by electrospinning and combined with human NSCs (hNSCs) for SCI treatment. The electrospun PLLA/PPSB nanofibrous scaffold containing 40 wt % PPSB demonstrated a highly porous microstructure, sulfonate group modification, strong hydrophilicity, suitable degradation performance, and good mechanical properties. The scaffold promoted the proliferation and further differentiation of hNSCs into neuronal cells. Moreover, the transplantation of hNSCs-loaded PLLA/PPSB nanofibrous scaffold attenuated the inflammatory response, enhanced the regeneration of neurons, and inhibited the growth of astrocytes in the lesion areas, thereby promoting the functional restoration of the spinal cord in rats with completely transected SCI. Thus, we conclude that the hNSCs-loaded PLLA/PPSB composites could promote the repair of spine cord injury. The findings could provide insight into the combined treatment strategies for SCI based on NSCs and bioactive biomaterials.