An enzymatic cascade system based on molybdenum-derived single atom nanozyme for bacteria infected wounds treatment

Abstract Resistant organism caused by overuse of antibiotics brings endless resistance in wound infections treatment. As a new generation of antibacterial strategy, which inspired by the irreversible oxidative damage to bacteria caused by reactive oxygen species (ROS), chemodynamics therapy has drawn considerable attention in recent years. However, the chemodynamics-mediate antibacterial effect is restricted owing to the near-neutral pH and insufficient H 2 O 2 concentration at infection site, and the addition of exogenous H 2 O 2 would cause serious side effects. Here, a molybdenum-derived single atom nanozyme (Mo-zyme) was prepared by the coordination of nitrogen atoms in zeolitic imidazolate frameworks with single-atom molybdenum. Subsequently, glucose oxidase (GOx) loading and hyaluronic acid (HA) encapsulation were accomplished via electrostatic attraction to form the nanozyme system (Mo/GOx@HA) with enzyme-activated cascade catalyzed property. Upon Mo/GOx@HA contacts with infected tissue, the catalytic reaction was triggered by bacteria-secreted hyaluronidase (HAase), leading to glucose oxidation and lowered the local pH, which could continuously provide H 2 O 2 for the in-situ generation of hydroxyl radicals (•OH) on bacteria surfaces, and advantageous to initiate the cascade-mediated antibacterial process. Wound infection treatment has demonstrated that the as-prepared Mo/GOx@HA exhibits excellent antibacterial and anti-inflammatory activity. This work provided a promising enzymatic cascade reaction nanoplatform for the treatment of bacteria infected wounds.