Fig. 11

Quantification of SA-β-gal positive cells that are treated with PENPs (10, 100 & 500 µg mL⁻¹), PSNPs (10, 100 & 500 µg mL⁻¹), NPs-1 (10, 50 & 100 µg mL⁻¹), and NPs-2 (10, 50 & 100 µg mL⁻¹) and H₂O₂ (10, 50 & 100 µM) for 48 h and then incubated with fresh, NPs-free medium. Micrographs were obtained with phase-contrast microscopy. Totally 250 cells scored from five images were expressed as the percentage (mean ± SEM) of positive cells. * p < 0.05, ** p < 0.01, *** p < 0.001 significantly different from the same NPs concentration. # p < 0.05, ## p < 0.01, ### p < 0.001 significantly different from the control