Fig. 3
Effects of 1, 5 and 20 µg/cm2 ZnO NPs on A549 cell survival. a, c, e and g Viability of A549 cells evaluated by MTT test after 24, 48, 72, and 144 h of treatment. b, d, f and h Colony numbers of A549 cells analyzed by cloning efficiency assay after 24, 48, 72, and 144 h of treatment. Rap (10 μM Rapamycin) and STS (1μM Staurosporine) were used as positive control of autophagy and apoptosis induction respectively. Experiments were performed in triplicate; * = p ≤ 0.05; p value Wilcoxon-Mann–Whitney test