Capacitive-coupling-responsive Hydrogel Scaffolds Offering Wireless in Situ Electrical Stimulation Promotes Nerve Regeneration.

Electrical stimulation (ES) has shown beneficial effects in repairing injured tissues. However, current ES techniques that use tissue-traversing leads and bulky external power suppliers have significant limitations in translational medicine. Hence, exploring non-invasive in vivo ES to provide controllable electrical cues in tissue engineering is an imminent necessity. Herein, we demonstrate a conductive hydrogel with in situ electrical generation capability as a biodegradable regeneration scaffold and wireless ES platform for spinal cord injury (SCI) repair. When a soft insulated metal plate is placed on top of the injury site as a wireless power transmitter, the conductive hydrogel implanted at the injury site can serve as a wireless power receiver, and the capacitive coupling between the receiver and transmitter can generate an alternating current in the hydrogel scaffold owing to electrostatic induction effect. In a complete transection model of SCI rats, the implanted conductive hydrogels with capacitive-coupling in situ ES enhanced functional recovery and neural tissue repair by promoting remyelination, accelerating axon regeneration, and facilitating endogenous neural stem cell differentiation. This facile wireless-powered electroactive-hydrogel strategy thus offers on-demand in vivo ES with an adjustable timeline, duration, and strength and holds great promise in translational medicine. This article is protected by copyright. All rights reserved.