Graphene-based conductive fibrous scaffold boosts sciatic nerve regeneration and functional recovery upon electrical stimulation

Peripheral nerve injury (PNI) is a very common consequence of traumatic injury and may cause serious disturbance in mediating functions in the human body. It's an urgent issue to promote the sufficient morphologic and functional regeneration of injured peripheral nerve. In this study, combination of graphene-based conductive fibrous scaffold (GCFS) and exogenous electrical stimulation (ES) were developed as an effective strategy to repair PNI, and the possible mechanisms underlying nerve recovery were further explored. The prepared GCFSs without or with 1.0 wt% graphene possessed electrical conductivity of 5.27 x10(-6) S/m and 3.12 S/m, respectively. The in vitro studies showed that ES could accelerate migration of rat mesenchymal stem cells (MSCs) seeded on the GCFS, promote the secretion of neurotrophic factors, and meanwhile up-regulate gene and protein expressions of neural markers. In vivo studies using a rat sciatic nerve injure model revealed that ES could significantly enhance sciatic nerve regeneration and functional recovery after implantation of GCFS nerve guidance conduit, and the daily ES exhibited repair-promoting capacity comparable to the gold standard autograft. Fundamentally, ES facilitated nerve regeneration maybe partly by the recruitment of endogenous MSCs and modulation of macrophage phenotypes. Taken together, GCFS combined with ES present a feasibility strategy to promote regeneration and functional recovery of the injured peripheral nerve. (C) 2020 Elsevier Ltd. All rights reserved.