An Fe–Cu bimetallic organic framework as a microwave sensitizer for treating tumors using combined microwave thermotherapy and chemodynamic therapy

Microwave thermotherapy (MWTT), as a treatment for tumors, lacks specificity and requires sensitizers. Most reported microwave sensitizers are single metal-organic frameworks (MOFs), which must be loaded with ionic liquids to enhance the performance in MWTT. Meanwhile, MWTT is rarely combined with other treatment modalities. Here, we synthesized a novel Fe-Cu bimetallic organic framework FeCuMOF (FCM) by applying a hydrothermal method and further modified it with methyl polyethylene glycol (mPEG). The obtained FCM@PEG (FCMP) showed remarkable heating performance under low-power microwave irradiation; it also acted as a novel nanospheres enzyme to catalyze H₂O₂ decomposition, producing abundant reactive oxygen species (ROS) to deplete glutathione (GSH) and prevent ROS clearance from tumor cells during chemodynamic treatment. The FCMP was biodegradable and demonstrated excellent biocompatibility, allowing it to be readily metabolized without causing toxic effects. Finally, it was shown to act as a suitable agent for T₂ magnetic resonance imaging (MRI) in vitro and in vivo. This new bimetallic nanostructure could successfully realize two tumor treatment modalities (MWTT and chemodynamic therapy) and dual imaging modes (T₂ MRI and microwave thermal imaging). Our findings represent a breakthrough for integrating the diagnosis and treatment of tumors and provides a reference for developing new microwave sensitizers.