NIR-II driven plasmon-enhanced cascade reaction for tumor microenvironment-regulated catalytic therapy based on bio-breakable Au-Ag nanozyme

Emerging nanozymes with natural enzyme-mimicking catalytic activities have inspired extensive research interests due to their high stability, low cost, and simple preparation, especially in the field of catalytic tumor therapy. Here, bio-breakable nanozymes based on glucose-oxidase (GOx)-loaded biomimetic Au-Ag hollow nanotriangles (Au-Ag-GOx HTNs) are designed, and they trigger an near-infrared (NIR)-II-driven plasmon-enhanced cascade catalytic reaction through regulating tumor microenvironment (TME) for highly efficient tumor therapy. Firstly, GOx can effectively trigger the generation of gluconic acid (H+) and hydrogen peroxide (H2O2), thus depleting nutrients in the tumor cells as well as modifying TME to provide conditions for subsequent peroxidase (POD)-like activity. Secondly, NIR-II induced surface plasmon resonance can induce hot electrons to enhance the catalytic activity of Au-Ag-GOx HTNs, eventually boosting the generation of hydroxyl radicals (center dot OH). Interestingly, the generated H2O2 and H+ can simultaneously induce the degradation of Ag nanoprisms to break the intact triangle nanostructure, thus promoting the excretion of Au-Ag-GOx HTNs to avoid the potential risks of drug metabolism. Overall, the NIR-II driven plasmon-enhanced catalytic mechanism of this bio-breakable nanozyme provides a promising approach for the development of nanozymes in tumor therapy.