Mechanisms and Applications of Conductive Biomaterials in Spinal Cord Injury Repair

Spinal cord injury (SCI) is a debilitating disorder of the central nervous system and remains a major challenge in neural regeneration and rehabilitation research. Spinal cord stimulation (SCS) has demonstrated notable efficacy in promoting neural repair and functional recovery following SCI. Its mechanisms include enhancing descending pathway conduction through neural plasticity, suppressing inflammation, and stimulating the secretion of neurotrophic factors, thereby creating a permissive microenvironment for axonal regeneration and remyelination. Nevertheless, in cases of complete SCI or extensive structural damage, SCS alone often shows limited therapeutic benefits. Advances in materials science have introduced conductive biomaterials as a promising strategy for SCI repair. These materials can replicate the spinal cord's electrical microenvironment, fill lesion sites, promote neural stem cell differentiation, guide directional axonal growth, facilitate remyelination, and modulate immune responses to mitigate secondary injury, collectively contributing to neuroprotection and functional recovery. This review systematically summarizes recent progress in the application of SCS and conductive biomaterials for SCI repair, highlights the current limitations of SCS in clinical settings, and provides an in-depth discussion on the mechanisms and translational potential of conductive biomaterials in neural regeneration.