Magnetically Responsive Piezoelectric Nanocapacitors Enhance Neural Recovery Following Spinal Cord Injury via Targeted Spinal Magnetic Stimulation.

Precise intracorporeal electrical-magnetic stimulation represents a promising strategy for promoting neural network reconstruction and motor function recovery after spinal cord injury. However, overcoming the inherent limitations of conventional intracorporeal electrical stimulation-such as infection risks from implanted wires and the logistical challenges posed by external power sources-while simultaneously improving the spatial precision of stimulation remains a major unmet need. Here, we introduce a novel therapeutic approach that integrates extracorporeal trans-spinal magnetic stimulation with energy-storing, sustained-release piezoelectric nanomaterials to generate precise, noninvasive electrical stimulation for spinal cord injury treatment. Experimental results demonstrate that these piezoelectric nanocapacitors induce current conduction across the dura mater in response to extracorporeal trans-spinal magnetic stimulation, thereby achieving highly localized and accurate electrical stimulation. Our findings show that this approach effectively promotes corticospinal tract axonal regeneration distal to the injury site, restores functional neural connectivity, and improves lower limb motor performance. Notably, the magnetically responsive piezoelectric nanocapacitors do not require open surgical implantation and are capable of delivering long-term, localized electrical stimulation. This strategy establishes a new paradigm for extracorporeal neuromodulation in spinal cord injury therapy and provides a promising foundation for the development of implant-free, remotely controllable neuromodulation systems.