Short- and long-term effects of silver nanoparticles on human microvascular endothelial cells

Figure 2 Silver nanoparticles induce the formation of reactive oxygen species, but antioxidants do not prevent silver nanoparticles’ cytotoxicity. A: HMEC cells were pretreated with antioxidants and then exposed to various concentrations of Ag or H₂O₂ (100 μmol/L) for 30 min. ROS generation was then measured. Data are shown as the fold increase in ROS levels of treated cells compared to the corresponding control. Each bar is the mean of three separate experiments ± SD. P value was calculated vs untreated cells: ^aP < 0.05, ^bP < 0.01, ^dP < 0.001; B: HMEC were pre-incubated with Trolox (40 μmol/L), NAC (5 mmol/L) or apocynin (10 μmol/L) for 2 h before adding different concentrations of Ag NP. MTT assay was performed after 24 h (B) and 72 h (C). Data are expressed as the percentage of control and represent the mean ± SD of four separate experiments. HMEC: Human dermal microvascular endothelial cells.