Multi-enzyme intelligent gold‑platinum‑cerium nanoplatform with reactive oxygen species amplification for photoacoustic/fluorescent imaging-guided photo/catalytic therapy.

The catalytic efficacy of nanozymes is severely limited by the insufficient hydrogen peroxide (H2O2) substrate and reactive oxygen species (ROS) production. Therefore, the development of multi-enzyme nanozymes with amplified ROS generation is urgently needed to enhance the antitumor effectiveness of catalytic therapy. In this study, we created a gold‑platinum@cerium dioxide (AuPt@CeO2) core@shell structure and modified the photosensitizer (IR808) to develop an intelligent nanoplatform (AuPt@CeO2-IR808) with ROS amplification for imaging-guided and photothermal-enhanced photo/catalytic therapy. In this nanoplatform, both AuPt and CeO2 exhibited enzyme-like activities of peroxidase (POD) and catalase (CAT). The generated H2O2 by AuPt enhanced the POD/CAT-like properties of AuPt@CeO2, significantly increasing the yields of hydroxyl radicals (·OH) and singlet oxygen (1O2). In addition, the AuPt@CeO2-IR808 nanoplatform possessed photothermal/photoacoustic (PA)/fluorescent performances, by which the enzyme activities were further accelerated, and the photoacoustic/fluorescent imaging was realized. By combining the photothermal/photodynamic/catalytic therapy of the AuPt@CeO2-IR808 nanoplatform, the yields of ·OH/1O2 were significantly amplified, leading to cell apoptosis and the destruction of mitochondrial function. Therefore, the developed multi-enzyme intelligent nanoplatform amplified ROS generation and achieved PA/fluorescent imaging-guided and photothermal-promoted photo/catalytic therapy toward breast cancer.