AgNPs inhibited H3N2 IFV infection of MDCK cells. (A) Treatment of H3N2 IFVs with AgNPs at different concentrations (12.5, 25, or 50 μ g/ml) for 2 hours prior to incubation with MDCK cells for a further 2 hours. Survival percentages of MDCK cells were determined by MTT assay after 48 hours of normal incubation. IFV control and solvent group experiments were performed in parallel. (B–F) Cytopathic effects observed under light microscopy. No obvious cytopathic effect was observed in mock cells (B) and cells treated with the solvent used for AgNP preparation (C). Obvious cytopathic effects were observed in the IFV control (D) and cells treated with a mixture of the solvent and virus (E). Minor cytopathic effects were observed in cells treated with the mixture of 50 μg/ml AgNPs and virus (F).
Notes: Values shown are the mean ± standard deviation for three independent experiments (n=5 in each group). The data are significantly different at §§P<0.01 versus IFV control. Scale bar, 600 μm.
Abbreviations: AgNPs, silver nanoparticles; IFV, influenza virus; MDCK, Madin-Darby canine kidney; 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT).