Bioswitchable Antibacterial Coatings Enable Self‐Sterilization of Implantable Healthcare Dressings

Abstract Healthcare‐acquired bacterial infections are a threat to public health. Therefore, development of self‐sterilizing implantable dressing materials is in increasing demand. Herein, a series of quaternized triblock copolymers, namely, QP‐ b ‐PCL‐ b ‐QPs, are synthesized and self‐assembled into reverse micelles (RMs) in tetrahydrofuran. The RMs contain biocompatible poly(ε‐caprolactone) (PCL) blocks in the shell to render biosafety and responsiveness, and biocidal quaternary blocks in the core to render antibacterial activity. In the presence of bacterial lipase, the biodegradable PCL blocks are hydrolyzed, resulting in the responsive release of quaternary biocidal agents (QBAs) to enable self‐sterilization. The RMs can be facilely impregnated into commercial gelatin sponge (GS) to fabricate RM 2 ‐coated GS, which impose potent antibacterial activity in the presence of lipase. Compared to Gram‐negative P. aeruginosa , the Gram‐positive S. aureus and B. subtilis are more susceptible to QBAs released from RM 2 ‐coated GS. The in vivo antibacterial assays and histological analyses further confirm the validity of RM 2 ‐coated GS in reducing bacterial infection in mice model. These results, taken together, provide a promising strategy for the development of bioswitchable self‐sterilizing dressing materials to reduce healthcare‐acquired bacterial infections.