Multifunctional nanocomposite chitosan-based hydrogel promotes healing of infected wounds through sustained release of Zn2+ and nicotinamide mononucleotide

Compromised cellular function and bacterial infection are major obstacles to effective wound healing. Simultaneous bacterial elimination and cellular function restoration represent a promising strategy for treating infected wounds. Here, a multifunctional hydrogel (QMPZN) composed of methacrylate anhydride (MA)-grafted quaternary ammonium chitosan (QCS-MA), polyvinyl alcohol (PVA), zeolitic imidazolate framework-8 (ZIF-8), and nicotinamide mononucleotide (NMN, a precursor of NAD + involved in cellular metabolism and repair) was developed to achieve combined antibacterial and regenerative effects. The hydrogel rapidly forms in situ under UV light via methacrylate double bond cross-linking, enabling application to irregular wound surfaces. PVA enhances its mechanical strength and tissue adhesion through hydrogen bonding. Benefiting from quaternary ammonium groups and the sustained Zn 2+ release from ZIF-8, QMPZN exhibits strong and durable antibacterial activity. Meanwhile, the controlled release of NMN helps restore cellular function and promote tissue regeneration. In vivo studies showed that QMPZN effectively inhibited bacterial infection and accelerated epithelial regeneration and collagen deposition in infected wounds. These results suggest that QMPZN hydrogel is expected to be a therapeutic platform for the treatment of infected wounds.