Nanozymes for Catalytic Cancer Immunotherapy

Nanozymes are nanoparticles with enzyme-mimicking properties. With the intrinsic catalytic properties, nanozymes are endowed with merits to modulate the immunosuppression of tumor immune microenvironment (TIME), mainly through altering reactive oxygen and nitrogen species (ROS/RNS) level. Besides redox imbalance, nanozymes can modulate other features of TIME, such as hypoxia. Modulations of TIME enabled by nanozymes can improve the effectiveness and efficiency of cancer therapies, especially immunotherapy. Two types of nanozymes, metal/metal oxide nanozymes and deoxyribozymes (DNAzymes) are currently investigated in cancer immunotherapy. They either act as standalone therapeutics or synergize with other therapeutic strategies to enhance antitumor effects. This Review summarizes the common nanozymes and their enzymatic properties, their interactions with TIME, and recent achievements of using nanozymes in cancer immunotherapy.