Silver Nanoparticles are very well established as broad spectrum antimicrobial and are used now days in many products and medical devices like wound dressings, implants, etc. for its antimicrobial properties. There is ample evidence of broad-spectrum antiviral activity of Silver Nanoparticles in form of authentic published research papers. The antiviral activity of Silver Nanoparticles has been found against over 24 different viruses including HIV-1, HSV-1, Respiratory syncytial virus, Monkeypox virus, Influenza virus, Hepatitis B Virus, etc. No other antiviral agent exhibits such broad-spectrum antiviral activity. Broad Spectrum and non-specific antiviral are the need of the hour when there is no or little information and knowledge about the COVID-19 virus.
The broad spectrum and non-specific mode of action of Silver Nanoparticles is because of its nano size much smaller than the size of microbes, due to which it can easily penetrate the cell walls and is presumed that it inhibits the growth by suppressing respiratory enzymes and electron transport components and through interference with DNA functions.
It is known that Silver Nanoparticles bind with viral envelope glycoprotein and inhibit the virus by binding to the disulfide bond regions of the CD4 binding domain within the HIV-1 viral envelope glycoprotein gp120, as suggested by Elechiguerra Et al. This fusion inhibition was also demonstrated by Lara Et al.