(a) Schematic illustration of Zr-fum functionalization, and (b) its performance. (c) Average size and zeta potential of Zr-fum and functionalized Zr-fum as a function of pH. (d) HeLa cell viability 24 h following MOF treatment. € Median fluorescence intensities of calcein-positive cell subpopulation. (f) Confocal images depicting HeLa cells. Blue, yellow, and green colors correspond to nuclei stained with DAPI, F-actin stained with phalloidin-rhodamine, and calcein, respectively. Reprinted with permission from [64]. Copyright 2019 American Chemical Society.