Nanocatalytic Tumor Therapy by Biomimetic Dual Inorganic Nanozyme‐Catalyzed Cascade Reaction

Abstract

Emerging nanocatalytic tumor therapies based on nontoxic but catalytically active inorganic nanoparticles (NPs) for intratumoral production of high-toxic reactive oxygen species have inspired great research interest in the scientific community. Nanozymes exhibiting natural enzyme-mimicking catalytic activities have been extensively explored in biomedicine, mostly in biomolecular detection, yet much fewer researches are available on specific nanocatalytic tumor therapy. This study reports on the construction of an efficient biomimetic dual inorganic nanozyme-based nanoplatform, which triggers cascade catalytic reactions for tumor microenvironment responsive nanocatalytic tumor therapy based on ultrasmall Au and Fe₃O₄ NPs coloaded dendritic mesoporous silica NPs. Au NPs as the unique glucose oxidase-mimic nanozyme specifically catalyze β-D-glucose oxidation into gluconic acid and H₂O₂, while the as produced H₂O₂ is subsequently catalyzed by the peroxidase-mimic Fe₃O₄ NPs to liberate high-toxic hydroxyl radicals for inducing tumor-cell death by the typical Fenton-based catalytic reaction. Extensive in vitro and in vivo evaluations have demonstrated high nanocatalytic-therapeutic efficacy with a desirable tumor-suppression rate (69.08%) based on these biocompatible composite nanocatalysts. Therefore, this work paves a way for nanocatalytic tumor therapy by rationally designing inorganic nanozymes with multienzymatic activities for achieving high therapeutic efficacy and excellent biosafety simultaneously.