Bioactive aligned PCL/CQD/Moringa nanofiber conduits accelerate peripheral nerve regeneration: in vitro and in vivo breakthroughs in sciatic nerve repair

Abstract

Nerve guidance conduits (NGCs) represent a promising strategy to support axonal growth and orientation during peripheral nerve regeneration. Polycaprolactone (PCL) offers suitable mechanical and biodegradable properties for NGC fabrication. To enhance its functionality, carbon quantum dots (CQDs) can improve physical and chemical properties, while Moringa oleifera extract contributes bioactive compounds that support neurogenesis and nerve repair. In this study, electrospun aligned nanofiber scaffolds composed of PCL, CQDs, and Moringa extract were fabricated and evaluated. Scaffolds containing both CQDs and Moringa showed improved mechanical strength, hydrophilicity, and degradation profile. The release of Moringa extract was quantified, and biocompatibility was confirmed via cell viability, adhesion, and differentiation assays using B65 and PC12 cells. These scaffolds significantly enhanced cell proliferation, neurite outgrowth, and neural differentiation, as demonstrated by DAPI staining, SEM, MTT, qRT-PCR, and immunocytochemistry. In vivo, a sciatic nerve transection model in rats was used to assess the regenerative potential of the conduits. After 12 weeks, improvements in sciatic functional index, electrophysiology, muscle recovery, and nerve histology were observed. Immunohistochemistry, qRT-PCR, and TEM further confirmed myelin sheath regeneration and neuromuscular recovery. These findings suggest that NGCs incorporating CQDs and Moringa extract provide a synergistic platform for promoting nerve regeneration and functional recovery, offering a novel and effective approach for the treatment of peripheral nerve injuries (PNI).