Exudate-triggered bio-based polyurethane hydrogel dressing containing herbal active ingredients for scald wounds healing.

Scald wounds present multiple challenges including hemorrhaging, bacterial infections, and permanent scar tissue formation. These issues emphasize the urgent need for smart wound dressings that dynamically respond to exudate changes in the wound microenvironment during healing process. In this study, a smart curcumin-based polyurethane hydrogel (BPUZ-P) loaded with natural Panax notoginseng saponin (PNS), an herbal active ingredient, was developed to deliver drugs on demand in response to exudate changes in wound microenvironment. The zwitterionic (Z-diol) incorporated into the BPUZ-P hydrogel ensures rapid tissue fluid absorption and hemostasis, while the synergistic effect of curcumin and quaternary ammonium salts confers effective antibacterial properties. In the acidic exudate microenvironment wound, the cleavage of hydrogen bonds between PNS and the acid-responsive functional groups in the hydrogel triggers controlled PNS release. These findings indicate that BPUZ-P exhibits multiple functions, including strong antioxidant activity, significant antimicrobial efficacy against E. coli and S. aureus, excellent biocompatibility and anti-inflammatory properties. When applied as a wound dressing, the BPUZ-P hydrogel demonstrates remarkable therapeutic efficacy by promoting collagen fiber formation, stimulating angiogenesis and significantly accelerating wound closure in scald models. This study highlights the potential of curcumin-based polyurethane hydrogels as smart wound dressings for the comprehensive treatment of bacterial infections in scald wounds.