Direct and capacitive electrical stimulation shapes neural progenitor cell survival and orientation on conductive scaffolds.

Electrical stimulation (ES) of neural progenitor cells (NPCs) on conductive biomaterials offers a promising strategy to enhance regenerative therapies for neurological disorders. In this study, we designed and evaluated two ES platforms, direct and capacitively coupled, using silver nanowire-integrated collagen scaffolds to investigate their effects on NPC orientation and viability. Direct stimulation promoted NPC alignment along the electric field, suggesting enhanced guidance potential for neural repair. In contrast, the capacitively coupled system did not alter cell morphology but improved viability by 3.8-fold (cells parallel to the electric field) and 2.1-fold (perpendicular) relative to controls, highlighting a safer, non-contact method to support cell survival. Importantly, in vivo implantation of the conductive biomaterial in a rodent stroke model did not appear to elevate astrocytic activation, supporting its biocompatibility within an injury-compromised brain environment. These findings reveal distinct advantages of each stimulation modality, the preference of NPCs to be aligned parallel to the applied electric field in both systems, and underscore the therapeutic potential of tuning electrical environments for NPC support.