A double-crosslinked self-healing antibacterial hydrogel with enhanced mechanical performance for wound treatment

Self-healing hydrogel systems usually suffer from poor mechanical performance stemmed from weaker and reversible non-covalent interactions or dynamic chemical bonds, which hamper their practical applications. This issue is addressed by adopting a double-crosslinking design involving both dynamic Schiff base bonds and non-dynamic photo-induced crosslinking. This leads to the formation of a special topological structure which simultaneously provide good self-healing capability and enhanced mechanical performance (elastic recovery and tensile modulus of 157.4 kPa, close to modulus of native skin). The quaternary ammonium and protonated amino groups can provide superior antibacterial capability; and Schiff base formation between residual aldehyde groups and amino groups on tissue surface contribute to hydrogel's adhesion to tissues (5.9 kPa). Furthermore, the multifunctional hydrogels with desirable mechanical performance, self-healing capability, superior antibacterial capability and tissue adhesion can significantly promote healing of infectious cutaneous wound, tissue remodeling and regeneration.