Poly(thioctic acid)-based supramolecular hydrogels with UV-triggered on-demand H₂S release for burn wound healing

Burn wound complicated by bacterial infection and exaggerated inflammatory response poses a significant threat to patients' lives. Hydrogen sulfide (H₂S) plays a critical role in wound healing, but its application is limited by low carrier loading efficiency and uncontrolled release behavior. Herein, an adhesive, self-healing, and removable supramolecular hydrogel integrating UV-triggered in situ production and on-demand release of H₂S and targeted recognition and killing of bacteria is developed based on poly(thioctic acid) (polyTA), acrylated adenine (AA) and phenylboronic acid-functionalized silver nanoparticles (AgNPs-PBA) to treat burn wound. The hydrogel exhibits high stability, rapid self-healing behavior, highly effective antibacterial activity through a targeted recognition strategy utilizing the boric acid group, adhesive property, UV-shielding property, removability, and on-demand delivery of H₂S, which effectively modulates pro-inflammatory cytokine levels (IL-6, TNF-α, and iNOS). In addition, the hydrogel demonstrates good cytocompatibility and anti-inflammatory, and promotes cell migration. Utilizing full-thickness defects of burns and infected burns, we demonstrated that the combined actions of targeted recognition/killing of bacteria and UV-triggered on-demand release of immunomodulatory H₂S significantly enhanced the burn wound healing process. This adhesive, self-healing, and removable supramolecular hydrogel dressing, with enhanced targeted recognition and killing of bacteria and on-demand in situ H₂S delivery, holds promising application in burn wounds.