Antimicrobial copper ion-graphene oxide composite to inhibit Pseudomonas Aeruginosa keratitis in rabbits

Biofilms and their associated infections have posed serious threats to the society from both an economical concern and a healthcare perspective. Graphene oxide (GO) has recently prompted the emergence of applications in the area of antibacterial materials owing to its high biocompatibility and surface functionalization. However, the weak biological interactions with microbial cells limit the antibiotic activity of GO. Herein, by combining GO with currently utilized antibacterial metal ions, copper ion-graphene oxide composite (Cu²⁺@GO) with exceptional bactericidal activity is achieved in this work. Cu²⁺@GO composite possessed more than 95% antimicrobial efficiency of both Staphylococcus aureus (S. aureus) and Pseudomonas aeruginosa (P. aeruginosa) compared with the Cu²⁺ only group or GO only group. Additionally, the composite inhibits the formation of bacterial biofilms, making it a potential candidate for the development of alternative antimicrobials. Antibacterial mechanism study shows that Cu²⁺@GO has both bacteria-binding ability and the property of producing reactive oxygen species (ROS) to cause the bacterial destruction. In vivo experiments indicate that Cu²⁺@GO possess an inhibition effect to P. aeruginosa-induced keratitis. Overall, this work demonstrates that Cu²⁺@GO may be promising antibacterial agents for the treatment of bacterial infection, which contributes to designing more antibiotic and safe graphene-based materials.