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

Abstract

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 (•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.