Extrusion-Stretched Multigrooved Conduits Loaded with Multiwalled Carbon Nanotubes for Efficient Peripheral Nerve Regeneration

Nerve guidance conduits (NGCs) represent a promising alternative to autologous nerve transplantation; however, their clinical efficacy remains limited by insufficient structural integrity and suboptimal fascicular guidance. Here, we report a novel extrusion-stretched strategy for fabricating multigrooved NGCs (MNGCs) reinforced with oriented multiwalled carbon nanotubes (MWCNTs). This scalable and controllable method effectively prevents conduit collapse during fabrication and enables precise regulation of conduit geometry, overcoming key limitations of conventional forming approaches. Incorporation of MWCNTs significantly enhanced the mechanical strength and biocompatibility of the conduits, as evidenced by improved Schwann cell (RSC96) viability, density, and pronounced aligned elongation compared with pure polycaprolactone (PCL) conduits. In a rat sciatic nerve defect model, the MWCNT-reinforced multigrooved NGCs (MMNGCs) achieved functional recovery, gastrocnemius muscle regeneration, and axonal myelination comparable to autografts while markedly outperforming single-lumen and groove-only PCL conduits. These results demonstrate that MMNGCs fabricated via the proposed extrusion-stretched strategy constitute a highly effective and clinically competitive platform for peripheral nerve repair.