Polydopamine-coated electroconductive nanofibrous scaffold with sustained NGF release for peripheral nerve regeneration.

Peripheral nerve injuries (PNIs) remain a major clinical challenge due to permanent functional impairment and limited effective therapeutic options. To address this, we developed a novel tissue-engineered nerve scaffold that integrates multiple regenerative elements to mimic a favorable microenvironment for nerve regeneration. The scaffold consists of electrospun aligned polycaprolactone (PCL) nanofibers for structural guidance of axonal growth, reduced graphene oxide (rGO) to provide electrical conductivity for enhanced neural signaling, and polydopamine (PDA) surface modification to improve hydrophilicity, promote cell adhesion, and enable the sustained release of nerve growth factor (NGF), thereby delivering continuous biochemical stimulation critical for neuronal growth and differentiation. In vitro, the multifunctional scaffold significantly enhanced PC12 cell proliferation and neurite extension, along with the upregulated expression of neuronal marker genes Tubb3 and Map2. In a 10 mm rat sciatic nerve defect model, it promoted robust axonal regeneration, myelination, and functional recovery, achieving outcomes comparable to autografts. These findings demonstrate that our scaffold effectively recreates a regenerative microenvironment through synergistic multifunctional cues, offering a promising alternative to autografts for treating PNIs.