Bienzymatic synergism of vanadium oxide nanodots to efficiently eradicate drug-resistant bacteria during wound healing in vivo

Antibiotic resistance is a common phenomenon observed during treatment with antibacterials. Use of nanozymes, especially those with synergistic enzyme-like activities, as antibacterials could overcome this problem, but their synthesis is limited by their high cost and/or complex production process. Herein, vanadium oxide nanodots (VO(x)NDs) were prepared via a one-step bottom-up ethanol-thermal method using vanadium trichloride as the precursor. VO(x)NDs alone possess bienzyme mimics of peroxidase and oxidase. Accordingly, highly efficient antibacterials against drug-resistant bacteria can be obtained through synergistic catalysis; the oxidase-like activity decomposes O-2 to generate superoxide anion radical (O-2(center dot-)) and hydroxyl radicals ((OH)-O-center dot), and the intrinsic peroxidase-like activity can further induce the production of (OH)-O-center dot from external H2O2. Consequently, H2O2 concentration could decrease up to four magnitude orders with VOxNDs to achieve an antibacterial efficacy similar to that of H2O2 alone. Wound healing in vivo further confirms the high antibacterial efficiency, good biocompatibility, and application potential of the synergistic antibacterial system due to the "nano" structure of VO(x)NIDs. The method of synthesis of nanodot antibacterials described in this paper is inexpensive, and the results of this study reveal the multi-enzymatic synergism of nanozymes. (C) 2019 Published by Elsevier Inc.