**3.2 Antiviral activity of AgNPs**

Nanoparticles present a viable substitute to pharmaceuticals in the management and regulation of viral pathogen proliferation. The process of biosynthesizing silver nanoparticles has the potential to yield highly effective antiviral agents that can effectively impede the functions of viruses. The bio-silver nanoparticles were investigated by Suriyakalaa et al. for their anti-HIV properties during the initial phase of the reverse transcription process, yielding compelling results [71]. Metallic nanoparticles synthesized through biosynthesis possess numerous binding sites for gp120 present in the viral membrane, thereby regulating the virus's functionality. According to another study, bio-based nanoparticles have been found to be efficient virucidal agents against both free HIV and cell-associated virus [72]. Studies have shown that silver nanoparticles exhibit antiviral properties against HIV-1 at concentrations that do not cause harm to cells. The present study aimed to assess the mechanism of antiviral activity of silver nanoparticles against HIV-1 through a range of in vitro assays [73]. According to a different study, the monkeypox virus was resistant to the antiviral effects of silver nanoparticles with or without a polysaccharide covering. The present investigation has revealed that silver nanoparticles exhibit significant inhibitory effects against monkeypox virus infection *in vitro* [74].

Pre-exposure of Tacaribe virus to silver nanoparticles was found to enhance the virus's cellular uptake in host cells. The observation was made that the introduction of silver treatment resulted in a noteworthy decrease in the production of viral RNA. This discovery serves as evidence that silver nanoparticles possess the ability to impede the infection of arenavirus *in vitro* [75]. According to a recent study, it was found that out of the three types of silver nanoparticle-MHCs that were tested, Ag30- MHCs exhibited the most effective viral inactivation [76].
