Ionic liquid-derived carbon dots with enhanced antibacterial activity and antibiofilm capability for treatment of MRSA-infected wounds

Abstract

Bacterial resistance to antibiotics has rendered bacterial infections an escalating threat to public health, prompting numerous researchers to strive towards the development of novel antimicrobial agents. Designable ionic liquids (ILs) have gained increasing prominence in the field of antibacterials. However, certain ILs exhibit suboptimal antimicrobial activity. In this study, we synthesized ionic liquid-derived carbon dots (IL-CDs: VOIMBr-CD) through vinyl and epoxy group reactions, resulting in enhanced antimicrobial efficacy. The VOIMBr-CD retains the antibacterial structure characteristic of ILs, including a positively charged imidazolium group and long alkyl chain. Moreover, VOIMBr-CD demonstrates selective antibacterial action against Staphylococcus aureus (S. aureus) while effectively inhibiting S. aureus biofilm growth. Notably, the antibacterial efficacy of VOIMBr-CD against methicillin-resistant Staphylococcus aureus (MRSA), surpasses vancomycin (Van). We conducted comprehensive investigations into the selective antibacterial mechanism of VOIMBr-CD which primarily involves electrostatic interactions, hydrophobic interactions, as well as generation of reactive oxygen species (ROS) within bacteria cells. In vivo experiments demonstrated that VOIMBr-CD significantly alleviate inflammation, facilitated collagen deposition and angiogenesis, and effectively expedited wound healing in MRSA-infected mice models; thus, highlighting their potential as therapeutic candidates for diseases resembling MRSA infection-like conditions. Importantly, this work presents a novel approach utilizing IL-based materials for developing effective antibacterials thereby offering new insights into the application prospects of IL-derived materials.