Modification of metal-organic framework composites as trackable carriers with fluorescent and magnetic properties

A fluorescent metal-organic framework (EuMOF) based on Eu³⁺ nodes coordinated by 1,1':2',1″-terphenyl-4,4',4″,5'-tetracarboxylate (H₄ttca) linkers has been developed as a trackable carrier with inherent fluorescence. Since Fe₃O₄ nanoparticles (NPs) have great value in versatile applications in vivo/vitro including imaging, cell isolation and magnetic responsivity, Fe₃O₄ NPs were introduced in the EuMOF composites to enhance the multifunctionalities. It has been demonstrated that the Fe₃O₄ NPs functionalized EuMOF composites have capability for tumor cell retrieval from matrix followed by anti-cancer drug release, which is promising to be developed as an integrated drug screening platform. Cytotoxicity was evaluated and the EuMOF-based nanocomposite exhibits significantly greater (up to 4x) biocompatibility tested on MCF-7 cells than the Zn-based MOF (the same ligand). Moreover, the EuMOF nanocarrier is capable of loading and releasing anti-cancer drugs in a controllable manner, where Doxorubicin (Dox) functionalized as a payload. Controllable release was successfully achieved after incubation with tumor cells and endocytosis analysis was obtained through the fluorescent imaging which offers monitoring of apoptosis after cargo release. Overall, fluorescent/magnetic properties of EuMOF has been investigated systematically, making it easy to be tracked in potential in vivo/vitro applications. As a drug carrier, it is biocompatible and shows highly efficient drug loading within 5 min, holding great promise in potential therapeutic delivery and other clinical applications.