Facile preparation of magnetic metal organic frameworks core–shell nanoparticles for stimuli-responsive drug carrier

Facile synthesis of core–shell magnetic MOFs for drug delivery is of significance due to the advantages of high drug load and easy separation. In this work, magnetic metal organic frameworks (MOFs, Fe₃O₄-NH₂@MIL101-NH₂) core–shell nanoparticles were synthesized rapidly in water phase by microwave irradiation using Fe³⁺ and 2-amino-1,4-benzenedicarboxylate (BDC-NH₂) as metal ions and ligands respectively. The resulting magnetic MOFs exhibit large surface areas (96.04 m² g⁻¹), excellent magnetic response (20.47 emu g⁻¹) and large mesopore volume (22.07 cm³ g⁻¹) along with spherical morphologies with the diameters ranging from 140–330 nm. Using doxorubicin (DOX) as a model drug, the drug loading capacity of Fe₃O₄-NH₂@MIL101-NH₂ could reach 36.02%, substantially higher than pristine MIL101-NH₂. Importantly, the release of DOX could be controlled by pH as well as the meso pore size of MOFs. The cytotoxicity assay showed that the magnetic MOFs have low cytotoxicity and good biocompatibility. The results suggest great potential of the magnetic MOFs core–shell nanoparticles fabricated in this study on controlled drug release of DOX. (paper)