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.