Carbon dots derivatizing from kanamycin with selective antimicrobial activity against Gram-negative bacteria and reactive oxygen species scavenging ability

Multidrug resistance in bacteria, especially in Gram-negative bacteria, has been an emerging issue for public health. The antibacterial agent with high antibacterial activity but avoiding drug resistance is highly desired. Carbon dots (CDs), as a new type of nano-antimicrobial agent, has attracted heightened attention due to their tunable physicochemical properties and high biocompatibility. In this study, we developed one kind of CDs, i.e., Kana-CDs, which was prepared based on the ternary carbon sources, including kanamycin, phenylboronic acid and citric acid. Kanamycin provided the antibacterial activity, while citric acid assisted the carbonization of kanamycin and stabilized the CDs, and phenylboronic acid endowed Kana-CDs with antibacterial selectivity. Kana-CDs behaved a good inhibitory effect on Gram-negative bacteria but not on Gram-positive ones. As well, Kana-CDs could inhibit/eradicate the biofilm formation, and eliminate excessive reactive oxygen species (ROS). Kana-CDs succeeded in treating E. coli -infected wound animal without significant toxicity on major organs. Compared to kanamycin, Kana-CDs was more stable with selective antibacterial activity towards Gram-negative bacteria, along with extra ROS scavenging activity and better wound healing efficiency. This study provided a new strategy for nano-derivatization of antibiotics for reducing drug resistance and improving antibacterial efficacy.