Guanidinium-Functionalized\nCarbon Dots: An Efficient\nAntibacterial Agent against Multidrug-Resistant ESKAPE Pathogens

The\nrise of multidrug-resistant (MDR) bacteria poses a substantial\nchallenge in clinical settings, particularly with the increasing prevalence\nof ESKAPE pathogens (E. faecium, S. aureus, K. pneumoniae, A. baumannii, P.\naeruginosa, and E. coli) as critical MDR bacteria. These ESKAPE pathogens have the capability\nto undermine antibiotic treatments, leading to a high incidence of\ndrug resistance. However, the development of efficient antibacterial\nagents against ESKAPE pathogens is still in the bottleneck. Herein,\nthe first example of antibacterial carbon dots against ESKAPE pathogens\nwas reported. Onion powder-based carbon dots were melted with poly(hexamethylene\nbiguanide) hydrochloride (PHMB) to obtain guanidinium-functionalized\ncarbon dots (GCDs), which exhibited satisfactory antibacterial activity\nagainst all the tested bacteria, including both Gram-positive and\nGram-negative bacteria, and even ESKAPE pathogens. The efficient antibacterial\nability of GCDs derives from the rupture of the bacterial cell membrane\nand elevated ROS levels. Safety assessments revealed that GCDs neither\ntrigger detectable drug resistance nor exhibit any cytotoxic effects.\nFurthermore, GCDs effectively promoted wound healing without observable\nadverse reactions of mixed MDR bacteria-infected wounds in rats. The\nGCDs also showed excellent long-term stability. These findings indicate\nthat GCDs hold promise as an efficient antibacterial agent for the\ntreatment of MDR strain-caused clinical infected-wound healing.