Exogenously Triggered Nanozyme for Real-Time Magnetic Resonance Imaging-Guided Synergistic Cascade Tumor Therapy.

The uncontrolled treatment process and high concentration of intracellular glutathione compromise the therapeutic efficacies of chemodynamic therapy (CDT). Here, iron oxide nanocrystals embedded in N-doped carbon nanosheets (IONCNs) are designed as a near-infrared light-triggered nanozyme for synergistic cascade tumor therapy. The IONCNs can absorb and convert 980 nm light to local heat, which induces the dissolution of iron oxide for generating Fe 2+ /Fe 3+ in a weak acid environment, apart from thermal ablation of cancer cells. The formed Fe 2+ takes on the active site for the Fenton reaction. The formed Fe 3+ acts as glutathione peroxidase to magnify oxidative stress, improving the antitumor performance. The IONCNs can be used to visually track the treatment process via magnetic resonance imaging. Such IONCNs demonstrate great potential as an exogenously triggered nanozyme via an integrated cascade reaction for imaging-guided synergistic cancer therapy.