Ultrasound-Responsive Aligned Piezoelectric Nanofibers Derived Hydrogel Conduits for Peripheral Nerve Regeneration.

Nerve guidance conduits (NGCs) have been considered as promising treatment strategy and frontier trend for peripheral nerve regeneration; while their therapeutic outcomes are limited by the lack of controllable drug delivery and available physicochemical cues. Herein, we propose novel aligned piezoelectric nanofibers derived hydrogel NGCs with ultrasound (US)-triggered electrical stimulation (ES) and controllable drug release for repairing peripheral nerve injury. The inner layer of the NGCs was the barium titanate piezoelectric nanoparticles (BTNPs)-doped polyvinylidene fluoride-trifluoroethylene [BTNPs/P(VDF-TrFE)] electrospinning nanofibers with improved piezoelectricity and aligned orientation. The outer side of the NGCs was the thermoresponsive poly(N-isopropylacrylamide) (pNIPAM) hybrid hydrogel with bioactive drug encapsulation. Such NGCs could not only induce neuronal oriented extension and promote neurite outgrowth with US-triggered wireless ES, but also realize the controllable nerve growth factor (NGF) release with the hydrogel shrinkage under US-triggered heating. Thus, the NGC could positively accelerate the functional recovery and nerve axonal regeneration of rat models with long sciatic nerve defects. We believe that the proposed US-responsive aligned piezoelectric nanofibers derived hydrogel NGCs will find important applications in clinic neural tissue engineering. This article is protected by copyright. All rights reserved.