CCK-8 assays were employed to evaluate the cytotoxicity of DIPT-ICF NPs against HeLa cells and NIH/3T3 cells. In brief, HeLa and NIH/3T3 cells were incubated in 96-well plates (Sarsteadt AG & Co. KG., Germany) at a density of 1 × 10 5 cells/mL. Post 24 h incubation, the cells were exposed to a various of doses of DIPT-ICF NPs. At 24 h post addition of DIPT-ICF NPs, the wells were washed with PBS (1×, pH 7.4) buffer and 100 µL freshly prepared medium containing CCK-8 solution (the volume ratio of CCK-8 was 10%) was added into each well, then the cells were kept in the incubator for 1.5 hours. Cell viability was expressed by the ratio of the absorbance of cells incubated with NPs to that of the cells incubated with culture medium only.