Preparation of nanoscale cationic metal-organic framework Nano Mn(III)-TP for theranostics based on valence changes

A single treatment strategy to produce a significant effect on cancer treatment is difficult due to the complex variability of the tumor environment. Herein, considering over-expressed glutathione (GSH) in the tumor environment can reduce Mn³⁺ to Mn²⁺, and Mn²⁺ exhibits an excellent T₁-weighted magnetic resonance imaging performance and a good Fenton-like effect. A Mn-based nano-cation metal-organic framework (MOF) with a size of about 200 nm was synthesized and labeled as Nano Mn(III)-TP. It showed an outstanding T₁-weighted MRI performance and Fenton-like effect due to valence changes of the Mn ions. Meanwhile, MTXNa@Nano Mn(III)-TP was obtained by loading with the anionic anticancer drug methotrexate disodium (MTXNa), and it could release MTXNa specifically in GSH solution with different pH values and temperatures, resulting in an improvement in the tumor suppressive effect of the Nano Mn(III)-TP. Based on the nanoplatform, the effective combination of magnetic resonance imaging (MRI), CDT and chemotherapy could be used as a potential therapeutic agent for multimodal therapy, which is also expected to be applied to clinical tumor treatment.