Electrically Preconditioned Engineered Neural Tissues Promote Structural and Functional Repair in Spinal Cord Injury Through Niche-Directed Neural Circuit Reconstruction

Spinal cord injury (SCI) creates a prohibitive microenvironment that limits the efficacy of neural stem cell (NSC) therapies. We developed electrically preconditioned engineered neural tissues (ENT) to address these limitations through: (1) pre-establishment of functional neural networks in vitro, and (2) enhanced host integration capacity. EGFP-expressing NSCs were differentiated in 3D Matrigel under 150 mV/mm physiological electric fields (EFs) and transplanted into T10 hemisection SCI mice. Outcomes were assessed through: Basso Mouse Scale (BMS) scoring, multiplex immunofluorescence (Nestin/MAP2/GFAP/MBP/Synaptophysin/ChAT), cortical somatosensory/motor evoked potentials (CSEP/CMEP), RNA sequencing and pathway analysis. We conducted a comprehensive evaluations of the histological structure and function of EF-preconditioned ENT and the mice that received ENT transplantation: (1) in vitro maturation of ENT: high neuronal differentiation, dense synaptic networks and myelinated axon; (2) in vivo integration: niche-directed migration (graft-derived cells showed central canal (Nestin+ cells) and grey matter (ChAT+ cells) homing), achieved functional synaptic integration and correlated with motor recovery. Mechanistic analysis revealed EF activation of pro-neuronal pathways and gliogenesis suppression. These results demonstrate that EF-preconditioned ENT enables structural neural network reconstruction, niche-directed homing, functional synaptic integration and significant motor recovery.