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(sic)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.