Inhibitory effects of silver nanoparticles against adenovirus type 3 in vitro

Adenoviruses are associated with respiratory, ocular, or gastrointestinal disease. With various species and high morbidity, adenoviruses are increasingly recognized as significant viral pathogen among pediatric and immunocompromised patients. However, there is almost no specific drug for treatment. Silver nanoparticles are demonstrated to be virucidal against influenza A (H1N1) virus, human immunodeficiency virus and Hepatitis B virus. Currently, there is no data regarding whether the silver nanoparticles inhibit the adenovirus or not. The aim of this study is to investigate the effect of silver nanoparticles on adenovirus type 3 (Ad3). The results revealed that HeLa cells infected with silver nanoparticles treated Ad3 did not show obvious CPE. The viability of HeLa cells infected with silver nanoparticles treated Ad3 was significantly higher than that of cells infected with untreated Ad3. There was a significant difference of fluorescence intensity between the cells infected with silver nanoparticles treated and untreated Ad3. The transmission electron microscopy (TEM) showed that silver nanoparticles could directly damage the structure of Ad3 particle. The PCR amplification products of DNA isolated from silver nanoparticles treated Ad3 was decreased in a dose-dependent manner. The decreased DNA loads were also confirmed by real-time PCR experiment. The present study indicates silver nanoparticles exhibit remarkably inhibitory effects on Ad3 in vitro, which suggests silver nanoparticles could be a potential antiviral agent for inhibiting Ad3 infection. (C) 2013 Elsevier B.V. All rights reserved.