Figure 3: Effect of MNPs on apoptosis. Acridine orange and alumen ferric staining of UM-SCC14A cells analyzed 24 hours post-incubation with or without MNPs. (A-C) Control experiment without MNP incubation. (D-G) Cells incubated with 0.35×1015, (H-K) 0.7×1015 and (L-O) 1.4×1015 particle/mL. Scale bars represent 10 μm. White arrows indicate cells in apoptosis, and red arrows indicate cells in the process of mitosis. (P) Graphic of the rate of apoptosis. Data are the mean ± SD. Within graphs, columns with different superscript letters differ significantly (p<0.001).