Cytotoxicity of Postmodified Zeolitic Imidazolate Framework-90 (ZIF-90) Nanocrystals: Correlation between Functionality and Toxicity

Using a simple method, the aldehyde groups of zeolitic imidazolate framework-90 (ZIF-90) nanocrystals were converted into carboxyl, amino, and thiol groups, without affecting the integrity of the framework. Notably, for the first time, correlations between functionality and cytotoxicity are also demonstrated via in vitro cytotoxicity assays. The positive charged aminated-ZIF-90 presumably results in either perturbation of cell membrane, more efficient cell uptake, or both. Therefore, the half-maximal effective (EC₅₀) concentration of aminated-ZIF-90 has a higher cytotoxicity of about 30 μg mL^-1. Supermodification: ZIF-90 (zeolitic imidazolate framework-90) nanocrystals were substituted with carboxyl, amino, and thiol groups without affecting framework integrity. In vitro cytotoxicity assays reveals that the positively charged aminated ZIF-90 presumably results in perturbation of cell membrane and/or more efficient cell uptake. The half-maximal effective (EC₅₀) concentration of aminated-ZIF-90 has a higher cytotoxicity (ca. 30 μg mL^-1).