Safety of metal-organic framework nanoparticles for biomedical applications: An in vitro toxicity assessment

Features such as high porosity, flexibility, and tunability of metal-organic frameworks (MOFs) have led to their promising applications in different biomedical domains such as the delivery of genes and drugs, biosensors, and contrast agents for magnetic resonance imaging. However, ensuring their safety and biocompatibility is un-avoidable when interacting with biological systems. before the bioapplication of MOF nanoparticles, toxico-logical assessments have to be established. In this study, four nano MOFs, hydrophobic ZIF-8 and UiO-66 and hydrophilic HKUST-1 and MIL-100, have been fabricated at the nanoscale and fully characterized by infrared spectroscopy, X-ray diffraction, and field emission scanning electron microscopy images. Then toxicity assess-ment was performed using four different cell lines including HeLa, MCF-7, HepG2, and HEK293. The MOFs were stable in the cell culture medium, even after 72 h incubation. It was found that ZIF-8 was more stable in com-parison with other ones. The synthesized nanoMOFs showed dose-dependent response against four cell lines. Our findings suggest that the prepared MOFs have no significant toxicity in concentrations below 50 mu g/ml. More-over, the obtained results showed that the toxicity of MOFs is associated with the nature of organic linkers and metal clusters.