Controllable synthesis of ultrasmall copper nanoparticles decorated fullerenol composite for antibacterial application and wound healing under visible light

Abstract

Developing an efficient antimicrobial agent is a key concern of present scientific community. Fullerene has been proved antibacterial by means of photodynamic therapy (PDT), but the severe hydrophobicity strongly hinders its application in biomedical fields. To solve this problem, a highly stable and water-soluble composite of which spherical fullerenol (hydroxylated fullerene) encapped by ultrasmall (5 nm sized) copper nanoparticles (CuNPs@fullerenol) was simply prepared by the combination of liquid-liquid interface precipitation (LLIP) and photochemical reduction strategy. Under the irradiation of 660 nm light for 15 min, 98.1 % E. coli and 97.6 % S. aureus treated by CuNPs@fullerenol was inhibited, while such bactericidal effect could be stably kept for at least 8 h. In vivo experiments also confirmed that the wound recovery could be accelerated by our therapy. Generation of radical oxygen species (ROS) including singlet oxygen (1O2) and superoxide anion (∙O2-) induced by PDT process, along with the metal ion release behavior, is considered as the mechanism for the excellent antibacterial performances of CuNPs@fullerenol. Our results will benefit the design and upgrade of nanocarbon-based antibacterial materials.