Surface-bound reactive oxygen species generating nanozymes for selective antibacterial action

Abstract

Acting by producing reactive oxygen species (ROS) in situ, nanozymes are promising as antimicrobials. ROS’ intrinsic inability to distinguish bacteria from mammalian cells, however, deprives nanozymes of the selectivity necessary for an ideal antimicrobial. Here we report that nanozymes that generate surface-bound ROS selectively kill bacteria over mammalian cells. This result is robust across three distinct nanozymes that universally generate surface-bound ROS, with an oxidase-like silver-palladium bimetallic alloy nanocage, AgPd0.38, being the lead model. The selectivity is attributable to both the surface-bound nature of ROS these nanozymes generate and an unexpected antidote role of endocytosis. Though surface-bound, the ROS on AgPd0.38 efficiently eliminated antibiotic-resistant bacteria and effectively delayed the onset of bacterial resistance emergence. When used as coating additives, AgPd0.38 enabled an inert substrate to inhibit biofilm formation and suppress infection-related immune responses in mouse models. This work opens an avenue toward biocompatible nanozymes and may have implication in our fight against antimicrobial resistance.

A Glucose‐Powered Activatable Nanozyme Breaking pH and H2O2 Limitations for Treating Diabetic Infections

“…Vaious nanozymes were designed and prepared based on metals, metal oxides, carbons, metal‐organic frameworks and other composite nanomaterials [7–10] . Great efforts also have been made for analytical, biomedical and environmental applications of nanozymes [11–16] …”

Nanozymes Regulate Redox Homeostasis in ROS-Related Inflammation

“…They are called photodynamic therapy (PDT) and sonodynamic therapy (SDT), respectively. Additionally, some nanoparticles with peroxidase-like activities, such as CuS particles ( Xi et al, 2019 ), MoO 3 nanodots ( Zhang et al, 2021a ), and AgPd 0.38 nanocages ( Gao et al, 2021 ), augment the generation of ˙OH, a cytotoxic ROS, by consuming hydrogen peroxide. They are used in organisms as antibiotics.…”

The Antimicrobial Activity of the AGXX® Surface Coating Requires a Small Particle Size to Efficiently Kill Staphylococcus aureus

“…Recently, metal-based nanoenzymes, such as the oxidase-like silver-palladium bimetallic alloy nanocage AgPd 0.38 were shown to produce ROS at the surface and selectively kill drug-resistant bacteria, but did not show toxicity in mammalian cells ( Gao et al, 2021 ). In addition, very promising metal-based antimicrobial surface coatings were developed, including AGXX® and the combination of functionalized graphene oxide (GOX) with AGXX®, termed as GOX-AGXX® ( Landau, 2013 ; Guridi et al, 2015 ; Vaishampayan et al, 2021 ).…”