Janus-structured Reg/PVA/PAN@TiO2 nanofiber dressing containing RegIIIγ recombinant antimicrobial peptides for promoting wound healing

Abstract

In clinical practice, the development of advanced wound dressings capable of simultaneously preventing infection and promoting healing remains a critical challenge. To address this, we engineered a Janus-structured nanofiber dressing RegIIIγ/polyvinyl alcohol/polyacrylonitrile@titanium dioxide (Reg/PVA/PAN@TiO₂) via electrospinning, incorporating the recombinant antimicrobial peptide RegIIIγ—obtained through genetic recombination—which exhibits dual functionality by preventing infection and accelerating wound healing. The bilayer architecture consists of a hydrophilic polyvinyl alcohol layer (Reg/PVA) for sustained release of RegIIIγ to enhance therapeutic utilization, and a hydrophobic polyacrylonitrile/TiO₂ (PAN@TiO₂) outer layer for barrier protection. The morphology, chemical structure, and thermal stability of the dressing were characterized, and the antibacterial activity, cell compatibility, and wound healing efficacy were evaluated through in vitro cell experiments and in vivo animal models, elucidating the wound healing mechanism of Reg/PVA/PAN@TiO₂. The results demonstrated that the Reg/PVA/PAN@TiO₂ nanofiber dressing exhibited excellent antibacterial properties (33.6 mm), robust mechanical performance (2.5 MPa) and biocompatibility with L929 fibroblasts (>80%). The dressing also significantly accelerated the wound healing process of full-thickness skin defects, reduced inflammatory responses, and promoted collagen synthesis and tissue regeneration. The healing speed and efficacy were significantly superior to those of the RegIIIγ drug alone. Therefore, the Reg/PVA/PAN@TiO₂ dressing, with its unique Janus design, potent antibacterial activity and superior pro-healing properties, has significant potential for clinical application in the management of infected wounds. It also offers a novel strategy to overcome the drawbacks of antimicrobial peptides, such as rapid degradation, short half-life and limited clinical efficacy.