A 5-fluorouracil-loaded BSA-Pd nanozyme inducing ROS burst and mild photothermal therapy for potent eradication of colorectal cancer.

Nanozymes have significant potential in human health applications. However, their use in tumor therapy has been restricted by limitations in tumor targeting and retention. Here, we report a 5-fluorouracil (5-Fu)-loaded BSA-palladium nanozyme (FBP) for synergistic treatment of colorectal cancer. The FBP nanozyme was fabricated by conjugation of bovine serum albumin (BSA) with the chemotherapy drug 5-fluorouracil, followed by thermal reduction-mediated precipitation of palladium nanozymes. The BSA shell enhanced biocompatibility and promoted tumor-targeted accumulation via the enhanced permeability and retention (EPR) effect. The FBP nanozyme exhibited both oxidase- and peroxidase-like properties, generating abundant reactive oxygen species to induce tumor cell death. Furthermore, FBP achieved efficient photothermal conversion under 808 nm laser irradiation, triggering 5-fluorouracil release and suppressing tumor growth by hyperthermia. This FBP-mediated photothermal ability was effective in eliminating tumors with negligible systemic toxicity. The findings demonstrate the efficacy of this novel nanozyme in combined photothermal treatment for colorectal cancer.