Cobalt-Doped Carbon Quantum Dots Work Synergistically with Weak Acetic Acid to Eliminate Antimicrobial-Resistant Bacterial Infections.

When pathogenic bacteria colonize a wound, they can create an alkaline ecological niche that selects for their survival by creating an inflammatory environment restricting healthy wound healing to proceed. To aid healing, wound acidification has been exploited to disrupt this process and stimulate fibroblast growth, increase wound oxygen concentrations, minimize proteolytic activity, and restimulate the host immune system. Within this study, we have developed cobalt-doped carbon quantum dot nanoparticles that work together with mild acetic acid, creating a potent synergistic antimicrobial therapy. The acidic environment alters the osmotic balance of microorganisms, forcing them to swell and speed up the internalization of the ultrasmall particles. The particles hyperpolarize the bacterial membranes and generate damaging peroxidase species, resulting in cellular lysis. In mice, cobalt-doped carbon quantum dots remove MRSA infection while allowing wounds to heal at rates equivalent to that of uninfected wounds. This work demonstrates how synergistic antimicrobial treatment strategies can be successfully used to combat antimicrobial-resistant infections.