Effect of JE22 and JE22-NPs (5) on MDA-MB-231 cell apoptosis. Representative scatter plots of PI (y-axis) versus FITC (x-axis) of cells after treatment with JE22-NPs (5) (20,000 NPs/cell), JE22 (EC50 and 4 × EC50), and Naked-NPs (1) (20,000 NPs/cell) for 24 h. Number of nanoparticles was determined by spectrophotometric analysis (see Figure S7). The cells were analyzed after double staining with Annexin V-FITC/PI by flow cytometry. Dot plots of H2O2 (2 mM, treatment of 4 h) and untreated cells were represented as the positive and negative control, respectively. Q1-4 quadrants represent necrotic (Annexin V-FITC-, PI+), late (Annexin V-FITC+, PI+), and early (Annexin V-FITC+, PI-) apoptotic and viable (Annexin V-FITC-, PI-) cells, respectively.