Reverse magnetic resonance tuning nanoplatform with heightened sensitivity for non-invasively multiscale visualizing ferroptosis-based tumor sensitization therapy.

Ferroptosis-based therapy has garnered considerable attention for its ability to kill drug-resistant cancer cells. Consequently, it holds great significance to assess the therapeutic outcomes by monitoring ferroptosis-related biomarkers, which enables the provision of real-time pathological insights into disease progression. Nevertheless, conventional imaging technology suffers from limitations including reduced sensitivity and difficulty in achieving real-time precise monitoring. Here, we report a tumor acidic-microenvironment-responsive nanoplatform with "Reverse Magnetic Resonance Tuning (ReMRT)" property and effective combined chemodynamic therapy (CDT) through the loading of chemotherapeutic drugs. This reverse MR mapping change is correlated with iron ion, reactive oxygen species (ROS) generation and drug release, etc., contributing to the precise monitoring of chemo-CDT effectiveness. Furthermore, the ReMRT nanoplatform presents as a highly efficacious combined chemo-CDT agent, and when this nanoplatform is used in conjunction with the "Area Reconstruction" method, it can afford a significant sensitivity (95.1-fold) in multiscale visualization of therapeutic, compared with the conventional MR R/R values. The high-sensitive biological quantitative imaging provides a novel strategy for MR-guided multiscale dynamic tumor-related ferroptosis therapy.