Noninvasive rapid bacteria-killing and acceleration of wound healing through photothermal/photodynamic/copper ion synergistic action of a hybrid hydrogel

Abstract

Bacterial infection often delays healing of wounded tissues and so it is essential to improve the antibacterial efficiency in situ. In this work, a hybrid hydrogel composed of 3-(trimethoxysilyl)propyl methacrylate (MPS, 97%) and mesoporous silica (mSiO₂) modified CuS nanoparticles (NPs) is synthesized by radical polymerization. The materials possess excellent and controllable photothermal and photodynamic properties under 808 nm near-infrared (NIR) light irradiation as well as an antibacterial efficacy of 99.80% and 99.94% against Staphylococcus aureus and Escherichia coli within 10 min, respectively. The excellent performance stems from the combined effects of hyperthermia, radical oxygen species, and released copper ions produced during NIR irradiation of CuS NPs. Moreover, the released copper ions stimulate fibroblast proliferation and angiogenesis and the intrinsic volume transition of the hydrogel composed of N-isopropylacrylamide (NIPAAm) and acrylamide (AAm) controls the release rate of copper ions during NIR light irradiation leading to both antibacterial effects and skin tissue regeneration.