3D printed nerve guidance conduit for biologics-free nerve regeneration and vascular integration

This work presents a biologics-free, 3D-printed nerve guidance conduit (NGC) fabricated using PEGDA–GelMA hydrogels through the custom Rapid Projection, Image-guided, Dynamic (RaPID) bioprinting system. The hexagonal microchannel design (300 µm diameter, 10 µm wall thickness) supports axonal alignment and regeneration across 4-mm sciatic nerve defects in mice. Introducing regularly patterned 50 µm micropores promoted extraneural vascular integration without compromising mechanical integrity or nerve guidance. Over 17 weeks, the conduits achieved full functional recovery of motor coordination and electrophysiological performance comparable to autografts, providing a clinically translatable, cell- and growth-factor–free alternative for peripheral nerve reconstruction.