Photo-enhanced catalytic activity enabled by core–shell nanozymes for combination breast cancer therapy

Abstract

Enhanced catalytic therapy of triple-negative 4T1 breast tumors through the application of photo-enhanced peroxidase (POD)-like and catalase (CAT)-like activities combined with chemotherapy could be enabled by core–shell nanozymes. Therefore, the dual POD and CAT-like activities of the core–shell iron oxide (Fe3O4)-@gold (IO@Au) nanozymes loaded with epirubicin (EPI) were evaluated in this study for photo-enhanced combination therapy. The core–shell nanozymes induced oxidative stress and apoptosis, and these effects were enhanced upon application of PDT, as demonstrated by ROS and caspase-3 activity assays. Additionally, it was shown that by reducing the expression of HIF-1α gene and upregulation of caspase-3 gene, core–shell nanozymes with and without PDT were able to induce a significant reduction in tumor weight, when compared to free EPI. The bio-distribution of the drug-loaded into core–shell nanozymes showed a higher accumulation of the EPI in the 4T1 breast tumor when compared to samples treated with free EPI. Overall core–shell nanozymes with catalytic-like activity can be used as potential platforms for photo-enhanced combination therapy.