Fluorinated Iron Metal-Organic Frameworks for Activatable 19 F Magnetic Resonance Imaging and Synergistic Therapy of Tumors.

Due to their appealing physiochemical properties, metal-organic frameworks (MOFs) have been widely employed in biomedical fields. In this study, we utilize ferric ions and fluorine-containing organic ligands as both structural and functional units to develop a stimulus-responsive nanoagent, 19 FIMOF-TA nanoparticles, for activatable 19 F magnetic resonance imaging (MRI) and synergistic therapy of tumors. This nanoagent could respond to excess GSH in a tumor microenvironment, discharging fluorinated organic ligands and reduced ferrous ions. The release of these fluorine-containing small molecules results in boosting of the 19 F MRI signals, which could be further enhanced by the photothermal effect of this nanoagent to achieve a responsive cascaded amplification of 19 F MRI signals for tumor visualization. Meanwhile, ferroptosis promoted by the ferrous ions leads to significant tumor cell death, which is synergistically aggravated by the photothermal effect. The encouraging results illustrate the promising potential of our nanoagent for effective tumor imaging and combinative cancer therapy.