Study on chimeric recombinant spider silk protein-P(LLA-CL) material for facial nerve repair in sd rats

OBJECTIVES: To address clinical challenges in the repair of superficial segmental nerve defects and to determine whether chimeric recombinant spider silk protein can guide directional axonal growth by enhancing cell adhesion, thereby providing a basis for the development of next-generation bionic nerve conduits. METHODS: MiSp and MaSp plasmids was blended with poly-L-lactide-poly-ε-caprolactone (P(LLA-CL)) at different ratios to fabricate electrospun composite membranes. The membranes underwent material characterization, in vitro biological evaluation, and in vivo nerve repair assessment. RESULTS: Composite membranes prepared with a 17% electrospinning solution and a 2:2 P(LLA-CL)/recombinant spider silk protein ratio demonstrated favorable properties, including well-defined fibrous structure, enhanced hydrophilicity, and improved cell adhesion and spreading. In vivo, rats implanted with this conduit showed superior facial function recovery at 8 weeks postoperatively; promoted axonal, myelin, and vascular regeneration at 1-4 weeks; and achieved myelin maturation by 8-12 weeks. DISCUSSION: A composite nerve conduit composed of P(LLA-CL) and recombinant spider silk protein at a 2:2 ratio (17% concentration) accelerates nerve defect repair by optimizing physicochemical properties and biocompatibility. These findings highlight a promising material candidate and provide an experimental foundation for clinical repair of superficial segmental nerve defects. Nonetheless, validation in large-animal models remains necessary to support clinical translation.