FePt@MnO-Based Nanotheranostic Platform with Acidity-Triggered Dual-Ions Release for Enhanced MR Imaging-Guided Ferroptosis Chemodynamic Therapy

Reactive oxygen species (ROS)-based anticancer therapy methods were heavily dependent on specific tumor microenvironments such as acidity and excess hydrogen peroxide (H2O2). In this work, an acidity-sensitive nanotheranostic agent (FePt@MnO)@DSPE-PEG5000-FA (FMDF NPs)  was successfully constructed for MR imaging guided ferroptosis chemodynamic therapy (FCDT) of cancer. The FMDF NPs could specifically target folic acid (FA) receptor-positive tumor cells (HeLa etc.) and induce ferroptosis efficiently by rapidly releasing active Fe2+ to catalyze intracellular H2O2 into ROS based on Fenton reaction. On the other hand, the Mn2+ could also be released due to acidity  and further coordinate with GSH to enhance the longitudinal-transverse relaxivity (T1/T2-weighted MR imaging), which could obviously strengthen the contrast distinction between solid tumors and the surrounding tissue to accurately real-time monitor the tumor location. Furthermore, the in vivo anticancer study revealed that the growth of solid tumo...