Size- and concentration-dependence of antiviral and virucidal activity of Au nanoparticles against adenoviruses and influenza viruses H1N1

Over the past 10 years, many scientific groups have experimentally shown that non-functionalized nanoparticles show a pronounced antiviral and antimicrobial action against different pathogens. In order to understand the mechanism of nanoparticles action it is important to know its peculiarities, i.e. dependences on different nanoparticles and pathogen properties.In this work we studied how Au nanoparticles act on the viruses outside and inside the cell, and compare this action for two sizes of nanoparticles and two types of the viruses. The study has been conducted for adenovirus and H1N1 influenza virus, and nanoparticles of 5 nm and 20 nm diameter.Virucidal and antiviral actions were observed experimentally for both types of nanoparticles against both viruses. It has been shown that intensity of virucidal action depends on the nanoparticles concentration non-monotonically for adenovirus. It has also been shown with electron microscopy that the viruses are destructed after 5 nm nanoparticles adsorption on their surface; and that the viruses change their shape after 20 nm nanoparticles adsorption on their surface. The model of physical adsorption of nanoparticles on the virus surface due to near-field interaction proposed in previous works may explain observed results on virucidal action of nanoparticles.