Engineering a wirelessly self-powered and electroconductive scaffold to promote peripheral nerve regeneration

Electroactive biomaterials have been shown useful for the repair of injured peripheral nerve. While for conventional conductive conduits, outer electrical stimulation device is unavoidably employed to exert electrical signals, and their rigid microstructures are usually incompatible with neural cells. Herein, a soft carbon nanotubes@gelatin methacryloyl/poly(L-lactic acid) (CNTs@GelMA/PLLA) nerve tissue-engineering scaffold was fabricated, which provided an endogenous piezoelectric stimulation and conductive microenvironment. Based on amounts of in-vitro experiment data, such composite scaffold significantly improved adhesion and elongation of Schwann cells, and meanwhile promoted axonal outgrowth and neurites number of dorsal root ganglions. More interestingly, the scaffold was applied to a 10-mm sciatic nerve defect in rats and harvested at 12 weeks post-implantation. Immunohistochemical staining results indicated that our proposed graft significantly facilitated peripheral nerve regeneration by promoting myelination and axon outgrowth, meanwhile an enhanced motor functional recovery caused by the scaffold was also revealed due to the obviously-improved sciatic functional index and muscle weights. Overall, the soft, self-powered, and electroconductive CNTs@GelMA/PLLA scaffold is a promising candidate for the treatment of peripheral nerve injuries.