Copper deposited diatom-biosilica with enhanced photothermal and photodynamic performance for infected wound therapy

Abstract

Considering the increase in drug resistance due to the abuse of antibiotics, the development of non-conventional antibiotics for the treatment of bacterial infections is necessary and urgent. In this study, copper deposited diatom-biosilica (Cu–DBs) was developed by a hydrothermal method for infected wound therapy. The deposition of Cu on Cu–DBs could significantly improve the photothermal and photodynamic performance of DBs, thereby increasing the yield of reactive oxygen species (ROS) under 808 nm laser irradiation. The light capture effect of DBs gave Cu–DBs stronger photothermal performance than Cu–NPs and significantly strengthened the sterilization effect of Cu–DBs. Cu–DBs (6 : 5) achieved almost 100% antibacterial efficiency against S. aureus and E. coli within 10 min, due to the synergistic effect of photothermal and photodynamic performance. In vivo experiments confirmed the antibacterial properties of Cu–DBs for infected wounds and proved that Cu–DBs could accelerate wound healing by inhibiting inflammation, promoting collagen deposition, adjusting the ratio of the type-III collagen to type-I collagen and promoting angiogenesis. Our study suggested that Cu–DBs possessed enhanced photothermal and photodynamic performance and had great potential in infected wound therapy.