Figure 4.

Photothermal effects on the cell death program of MG63 cells.

Notes: Cells treated with 5 ppm of AuNPs and laser irradiation of 80 mW/cm² for 1 minute and then cultured in fresh medium for 1 day. (A) Cells alone, (B) AuNPs alone, (C) laser alone, and (D) AuNPs plus laser. Dot plots of Annexin V/PI staining are shown. The upper-left quadrant shows the necrotic (Annexin V−/PI+) population. The upper-right quadrant shows the late apoptotic/necrotic (Annexin V+/PI+) population. The lower-left quadrant shows the vital (Annexin V−/PI−) population. The lower-right quadrant shows the early apoptosis (Annexin V+/PI−) population. The results are from one experiment and are representative of three similar independent experiments. (E) The percentages of viable cells, early apoptosis cells, late apoptosis cells, and necrotic cells are summarized from three independent experiments and are presented as the mean ± SD. Data were analyzed using the nonparametric Kruskal–Wallis H-test. Differences of P<0.05 were considered statistically significant.

Abbreviations: AuNP, gold nanoparticle; PI, propidium iodide; UL, upper left; UR, upper right; LL, lower left; LR, lower right; FITC, fluorescein isothiocyanate; SD, standard deviation; FSC-H, forward scatter-height of intensity; SSC-H, side scatter-height of intensity.