Gradual hydrogel degradation for programable repairing full-thickness skin defect wound

Full-thickness skin defect wound infection seriously threatens the life and health of patients. Highly efficient antibacterial activity and angiogenesis after injury are critical for the wound healing process. In this work, we first designed various of halogen-free imidazolium poly(ionic liquids) (PILs) as the antibacterial agents, and selected the highest efficient antibacterial PIL. Then, we fabricated hyaluronic acid/poly(ethylene glycol)/PILs semi interpenetrating polymer network (semi-IPN) wound dressings by Diels-Alder (DA) click reaction, and deferoxamine (DFO) which promoted angiogenesis was grafted into the hydrogel wound dressings. In vitro and in vivo assays respectively evaluated the fast antibacterial property of the hydrogels against Escherichia coli and Staphylococcus aureus at skin infected wound areas. With the hydrogels enzymatic degradation by hyaluronidase, the degradation solution could reduce inflammation, promote angiogenesis and wound healing due to the continuous releasing of DFO and PIL. The programable hydrogel degradation protocol provided a new strategy for rapid full-thickness skin defect wound healing in the clinic application.