Multifunctional Toona sinensis gum polysaccharide-based carbon dot-hydrogel composites for accelerated healing of infected wounds

Bacterial resistance, recurrent infections, and impaired wound healing pose significant challenges in clinical wound management. Natural biomass-derived carbon dots (CDs) have attracted considerable attention due to their synergistic antibacterial, anti-inflammatory, and biosafety, which facilitate the healing of infected wounds. In this study, carbon dots derived from Toona sinensis gum polysaccharide (TGP-CDs) were integrated into a gelatin-chitosan hydrogel to construct TGP-CDs@Gel. Experimental results demonstrated that TGP-CDs@Gel exhibits strong light-activated ROS generation capability, effectively disrupting bacterial biofilms and compromising membrane integrity through photodynamic antibacterial mechanisms. The composite also significantly promoted L929 fibroblast migration and protected RAW264.7 macrophages and N2 nematodes from oxidative stress. Importantly, TGP-CDs@Gel exhibited potent photodynamic antibacterial activity, as well as the regulation of pro-inflammatory cytokines and angiogenesis-related proteins (i.e., CD31, VEGF) in MRSA-infected wound, thereby significantly accelerating wound healing. Moreover, comprehensive biosafety evaluation confirmed its excellent biocompatibility across multiple models, including in vitro cell cultures, zebrafish, and nematodes. Collectively, TGP-CDs@Gel demonstrates promising photodynamic antibacterial and anti-inflammatory functions, providing a novel strategy for tissue regeneration and extending the application of Toona sinensis gum in biomaterials. Graphical abstract