Table 3.

Antiviral activity of AgNPs

Metal nanoparticles	Virus	Mechanism of action	References
Physical approach
AgNPs capped with mercaptoethane sulfonate (4 ± 1 nm)	HSV-1	Blocking of virus–host cell binding and penetration	Baram-Pinto et al. [163]
Graphene oxide sheets coated AgNPs (17 ± 3.4 nm)	Porcine reproductive and respiratory syndrome virus	Enhances the production of interferon-α (IFN-α) and IFN-stimulating genes (ISGs) Blocking of virus-host cell penetration	Du et al. [164]
PHBV-coated AgNPs (film diameter 1.1 ± 0.40 mm)	Norovirus surrogates	Decreased norovirus infectivity	Castro-Mayorga et al. [165]
Chemical approach
Polysaccharide-coated AgNPs (10 nm)	TV	A reduction in viral RNA production and prevents cell–host binding	Speshock et al. [194]
Polysaccharide-coated AgNPs (10–80 nm)	MPV	Blocking of virus–host cell binding and penetration	Rogers et al. [166]
PVP-coated AgNPs (30–50 nm)	HIV	Inhibition of the interaction between gp120 and the target cell membrane receptors	Lara et al. [168]
Curcumin-coated AgNPs (45 nm)	HIV	Inhibited expression of HIV-1 LTR and p24, the cytokines, IL-1β, TNF-α, and NF-κB	Sharma et al. [169]
AgNPs (10–50 nm)	HBV	Possess high binding affinity for HBV DNA and extracellular virions and inhibit HBV RNA production	Lu et al. [170]
PQPOCs-coated with AgNPs (NR)	Hepatitis A virus (HAV), norovirus (Nov) and coxsackievirus B4 (Coxb4)	Binding of AgNPs to the virion active sites Prevents viral RNA transcription and translation by inducing ribonuclease	Sofy et al. [173]
PVP-coated AgNPs (69 ± 3 nm)	RSV	Interference with viral attachment	Sun et al. [171]
PVP coated AgNPs (8–12 nm)	RSV	Reduction in RSV replication and reduction in cytokines and chemokines	Morris et al. [172]
Silica-coated with AgNPs (400 nm)	IFV-A	Interaction with viral components located in the membrane and caused nonspecific damage to various IFV-A components	Park et al. [177]
AgNPs coated with lipoic acids (NR)	IFV-A	AgNPs enhanced specific IgA secreting plasma cells and antibody titers	Sanchez-Guzman et al. [195]
Oseltamivir (OTV) coated with AgNPs (2–3 nm)	H1N1	Inhibits the activity of neuraminidase (NA) and hemagglutinin (HA) and then prevents cell–host binding Inhibits the accumulation of reactive oxygen species (ROS) by the H1N1 virus	Li et al. [175]
AgNPs (9.5 ± 0.8 nm)	H3N2	Interact with virus cell, resulting in the destruction of morphological viral structures Inhibits the activity of neuraminidase (NA) and hemagglutinin (HA) and break the protein	Xiang et al. [176]
Citrate/lipoic acids coated with AgNPs (13.3–17.1 nm)	Influenza virus infection of lung epithelial cells	Inhibits RIG-I production Enhances IL-8 production	Villeret et al. [196]
Magnetic colloid AgNPs (~ 500 nm)	Murine norovirus and adenovirus serotype 2	Interactions with viral surface proteins. AgNPs bind the thiol group-containing biomolecules embedded in the coat proteins of viruses	Park et al. [179]
PVP coated AgNPs (35 nm)	Rift Valley Fever virus	Inhibits virus–cell binding and penetration	Borrego et al. [197]
Glutathione-capped silver sulphate (Ag2S) nanoclusters (3.7–5.3 nm)	Porcine epidemic diarrhea virus Coronavirus	Inhibits the synthesis of viral negative-strand RNA and viral budding. Regulate the generation of IFN-stimulating genes (ISGs) and the expression of pro-inflammatory cytokines	Du et al. [164]
AgNPs and silver nanowires (20 and 60–400 nm)	Transmissible gastroenteritis virus (TGEV)	Diminished the infectivity of TGEV and decreased the number of apoptotic cells induced by TGEV	Lv et al. [198]
Agrovit coated with PVP (35 ± 15 nm)	White Spot Syndrome Virus (WSSV)	Interact with WSSV envelope proteins and block the specific binding to membrane proteins of shrimp host cells	Romo-Quiñonez et al. [181]
Graphene coated with AgNPs (30–50 nm)	Anti-tomato bushy stunt virus (TBSV)	Enter the cell, interacts with viral nucleic acids and deactivate it	Elazzazy et al. [199]
AgNPs (14 nm)	African swine fever virus	Interact with glycoprotein on the exterior membrane, preventing the virus entry into cells or the virus replication and thereby cause the viral inhibition	Tran et al. [180]
Biological approach
AgNPs using various fungi (20–46 nm)	HSV and human parainfluenza virus type 3	Block interaction of the virus with the cell Inhibit virus replication	Gaikwad et al. [183]
Chitosan coated with AgNPs (NR)	H1N1	Bind with viral envelope glycoproteins and inhibits viral penetration into the host cell Physical binding of virions to composite	Mori et al. [174]
AgNPs using Panax ginseng roots (9–11 nm)	IFV-A	Blocking of virus-host cell binding and penetration	Sreekanth et al. [185]
AgNPs using Lactobacillus fermentum (11.2 ± 0.9 nm)	Murine norovirus 1	Interacts with the proteins of the MNV-1 capsid and prevents virus–host penetration	De Gusseme et al. [184]
AgNPs using leaves of M. alternifolia (11.56 nm)	HSV-1 and HSV-2	Reduction of the cytopathic effect for HSV-1 and HSV-2	Ramadan et al. [200]
AgNPs using seaweed Sargassum wightii (NR)			[187]
AgNPs with tannic acid from plant (33 ± 7 nm)	HSV-2	Block the infectivity of HSV-2	Orłowski et al. [188]
AgNPs by Citrus limetta peels (5 nm)	Chikungunya virus (CHIKV)	Reduced CHIKV viral titer and viral RNA level	Choudhary et al. [189]
AgNPs using Argemone mexicana leave extract (5 – 30 nm)	Peste des petits ruminant virus	Inhibits virus replication and interact with the virion surface as well with the virion core blocking virus–host cell penetration	Khandelwal et al. [191]
AgNPs using Bacillus sp. (77–92 nm)	Bean yellow mosaic virus	Enter the cell, interacts with viral nucleic acids and deactivate it	Elbeshehy et al. [192]
AgNPs using freshwater microalgae (22.5–57.5 nm)	Newcastle disease virus	Bind with the virus glycoprotein envelope, thus restricting virus penetration in host cells	Khalid et al. [193]

NR not reported; AgNPs AgNPs; MPV monkeypox virus; PVP polyvinylpyrrolidone; PQPOCs polyquaternary phosphonium oligochitosans; TV Tacaribe virus; IFA-V influenza A virus; PHBV poly (3-hydroxybutyrate-co-3-hydroxyvalerate); HIV human immunodeficiency virus; HBV hepatitis B virus; RSV respiratory syncytial virus; HSV-1 and HSV-2 herpes simplex virus type 1 and 2