Quaternized chitosan coated copper sulfide nanozyme with peroxidase-like activity for synergistic antibacteria and promoting infected wound healing.

Bacterial infection can hinder the infected wound healing process. Because of the growing drug-resistance bacteria, there is an urgent desire to develop alternative antibacterial strategies to the antibiotics. Herein, the quaternized chitosan coated CuS (CuS-QCS) nanozyme with peroxidase (POD)-like activity was developed through a facile biomineralized approach for synergistic efficient antibacterial therapy and wound healing. The CuS-QCS killed bacteria by the electrostatic bonding of positive charged QCS with bacteria and releasing Cu2+ to damage bacterial membrane. And importantly, CuS-QCS nanozyme exhibited higher intrinsic POD-like activity, which converted H2O2 with low concentration into highly toxic hydroxyl radical (OH) for the elimination of bacteria by oxidative stress. Through cooperation of POD-like activity, Cu2+ and QCS, CuS-QCS nanozyme exhibited excellent antibacterial efficacy of approximate 99.9 % against E. coli and S. aureus in vitro. In addition, the QCS-CuS was successfully used to promote the healing of S. aureus infected wound with good biocompatibility. This synergistic nanoplatform presented here shows great potential applications in the field of wound infection management.