2.11. Measurement of Cytotoxicity Using MTT Assay

SW480 and HeLa cells (4.5 × 10³ cells per well) were seeded into 96-well plates. After 24 h, the media was changed to non-serum RPMI 1640, and after a further 24 h, the cells were treated withJC-Fe₃O₄ and CT-Fe₃O₄ NPs at different concentrations. The treated cells were incubated for 48 h, washed with cold PBS, and then exposed to MTT with media for 4 h. The media was changed to DMSO, and the dissolved formazan dye was quantified by measuring the absorbance at 540 nm. As a control, untreated cells were examined in the same manner.