Manganese oxide/Metal-Organic Frameworks-Based Nanocomposites for Tumr Micro-environment Sensitive 1H/19F Dual-mode Magnetic Resonance Imaging in Vivo

A pH- and GSH-responsive H-1/F-19 dual-mode magnetic resonance imaging contrast agent (MRI CA) was constructed by incorporating MnOx into Zr-based MOF nanoparticles (MnOx/UiO-66-F/PPEG NPs) with an organic ligand of tetrafluoro-terephthalic acid (F(4)PTA). Under a weak acidic tumor micro-environment, MnOx/UiO-66-F/PPEG NPs would collapse to release MnOx and free F(4)PTA. Due to the released free F(4)PTA, F-19 MRI signal was enhanced. Meanwhile, GSH, which is overexpressed in a tumor micro-environment, reduced MnOx to divalent manganese ions and improved the T-1-weighted MR imaging capability. As a proof of concept, MnOx/UiO-66-F/PPEG NPs was favorable for dual H-1/F-19 MRI with a high signal-to-noise ratio in vivo. (C) 2020 Published by Elsevier B.V.

Automated summary

A pH- and GSH-responsive dual-mode MRI contrast agent was developed by incorporating MnOx into Zr-based MOF nanoparticles, showing enhanced signal in tumor micro-environment and potential for dual H-1/F-19 MRI imaging.