Figure 6

Apoptosis of HEK293 cells induced by SWCNTs. a morphological changes of HEK293 cells cultured with 25 μg/mL SWCNTs for 3 days; a0: showing cells become round and floating with apoptotic characterizatics; control: showing normal morphological cells; a1: showing nodular structure composed of SWCNTs and apoptotic cells; a2: showing apoptotic cells attached by SWCNTs. b1: DNA electrophoresis of cells cultured with 25 μg/mL SWCNTs for 1–5 days, M: molecular Marker; no. 1–5 denote the results of cells cultured for day 1–5, respectively; b2: DNA electrophoresis results of control cells cultured for day 1–5; c: the cell cycle distribution of HEK293 cells cultured with 25 μg/mL SWCNTs for 4 days, the percentage of sub-G1 cells (apoptosis cells) was 43.5% [77]