Injectable Self‐Healing Hydrogel Wound Dressing with Cysteine‐Specific On‐Demand Dissolution Property Based on Tandem Dynamic Covalent Bonds

Rapid gelation and on-demand dissolution are key characteristics governing the effectiveness of clinic hydrogel wound dressings. Here, an injectable self-healing hydrogel with rapid gelation and cysteine-specific on-demand dissolution is designed to be used as wound dressings. The hydrogel is prepared based on the formation of tandem dynamic covalent bonds comprised of CC double bonds produced through the catalysis-free Knoevenagel condensation reaction and boronate ester linkages. The prepared hydrogel displays excellent injectability and self-healing ability, showing rapid cysteine-triggered on-demand dissolution owing to the formation of the thiazolidino boronate complex. When used as dressings for healing full-thickness wounds, the hydrogel shows favorable biocompatibility, achieves rapid wound closure in seconds, and fast on-demand dissolution for dressing changes. These data highlight the utility of the designed tandem dynamic covalent bonds-based hydrogel dressings for promising wound healing applications.