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Antiviral Activity of Graphene–Silver Nanocomposites against Non-Enveloped and Enveloped Viruses


Many eukaryotic viruses invade the nucleus to access the cellular replication and transcription machineries that are necessary for their multiplication. PEI-magnetic beads adsorbed efficiently the enveloped viruses Sindbis virus and Herpes simplex 1 virus, and the nonenveloped virus SV-40, but not the nonenveloped viruses porcine parvovirus (PPV) or poliovirus, based on the PCR detection data. This finding highlights potential similarities and differences between HSV1 and the related alphaherpesvirus, pseudorabies virus, in which the homologues of all three of these tegument proteins are not incorporated into the virion until secondary envelopment. These studies demonstrate that protein denaturants are generally effective for virus inactivation but with the limitation that only some may inactivate non-enveloped viruses. 82:12126-12144, 2008; Veettil et al., PLoS Pathog. disinfectant concentration and disinfectant contact time. Based on these criteria and despite its tenacity being inferior to that of BPV, the ECBO virus was chosen as the most suitable test virus.

TF-3 inactivated HSV-1 and HSV-2 by 4 to 5 log(10) in the pH range of 4.0 to 5.7. The possibility to formulate antivenoms at low pH requires further investigations to avoid formation of aggregates. Nevertheless, all capsid types underwent active axonal transport. Limited studies have found that Ag NPs show antiviral activity against human immunodeficiency virus [1,4,5,6], hepatitis B virus [7], herpes simplex virus type 1 [8], respiratory syncytial virus [9], monkey poxvirus [10], Tacaribe virus [11], and H1N1 influenza A virus [12,13,14]. All the RNA and DNA viruses mentioned previously contain lipid envelopes. No antiviral effects of Ag NPs on non-enveloped viruses have been investigated.

Antiviral Activity of Graphene–Silver Nanocomposites against Non-Enveloped and Enveloped Viruses

Although the transmission of viral diseases has been reduced by the development of good water supplies and hygienic-based procedures for a whole range of human activities [1], pathogenic viruses are still the causative agents of many diseases in humans and other species. This is the case whether viruses acquire their lipid envelope by directly budding through the plasma membrane, or by budding/wrapping at intracellular membranes whereby virions become contained within the lumen of that compartment (with example assembly sites including the endoplasmic reticulum, trans-Golgi network, and endosomes). A number of fatty acids which are normal components of milk lipids were tested against enveloped viruses, i.e., vesicular stomatitis virus, herpes simplex virus, and visna virus, and against a nonenveloped virus, poliovirus. Therefore, there is an urgent need to develop safe and potent topical microbicides under the control of women to efficiently reduce the spread of sexually transmitted infections. Over the last 30 years, research has thus focused on the development of new antiviral agents able to positively impact the spread of viral infections. Membrane-associated KΔUL36GFP also displayed a slightly decreased binding to microtubules in our microchamber assay and a two-thirds decrease in the frequency of motility. Le, Tao.

This compartment contains more than 15 different virally-encoded proteins for which many of their functions remain unknown. Since non-enveloped viruses do not have a lipid envelope, it is generally believed that their entry mechanism does not involve membrane fusion activity and that these viruses are mainly released by cell lysis. This antibody was shown to recognize a bovine protein with a significant sequence homology to porcine and human CD46 (22). The family Iridoviridae is phylogenetically linked to several other families of nuclear, cytoplasmic, large, DNA-containing viruses (NCLDV) such as Phycodnaviridae, Poxviridae, Asfaviridae, Ascoviridae, and Mimiviridae [4–7]. The small oil particles are diluted by waves into very minute concentrations (6). Outbreaks of influenza virus infection occur every year and sometimes cause fatal diseases including pneumonia, secondary bacterial pneumonia and encephalopathy [3]. Examples include B-cell and T-cell receptors, as well as receptor-associated adaptor proteins such as DAP12 (1).

These results, coupled with the marked preference for arginines over lysines in α-defensins, imply that other aspects of arginine residues are more important than simple charge [6], [9]. The solution to this problem is a staged assembly process in which a procapsid is assembled under conditions required for accurate self-assembly, but the resultant particle carries within it an encoded program for maturation that dictates events to transform the initial assembly product into a robust virion, satisfying the second purpose of maturation. Numerous works described the antiviral activity of algal carbohydrate polymers [6]–[7] leading to promising therapeutic applications when used either alone or associated with existing antiviral drugs. Once the fusion protein has positioned the viral envelope in close proximity to the cellular membrane, hemifusion, in which the outer leaflets of the viral and cellular lipid bilayers fuse, can occur (). UL36p (VP1/2) is the largest structural protein encoded by the herpesviridae (20, 21). The emerging picture is that each virus has evolved a unique strategy to deliver its genome into the nucleus. Although enveloped viruses such as these possess a fixed number of proteins arranged with icosahedral symmetry in the envelope, high-resolution diffraction data remain elusive.


Determination of Cytotoxicity of GO or GO-Ag Cytotoxicity of GO or GO-Ag to fcwf-4 cells was determined in terms of the concentration of GO or GO-Ag, causing 50% of cells to die (cytotoxicity concentration, CC50), by using MTS assay (CellTiter 96® AQueous One Solution Cell Proliferation Assay, Promega, Madison, WI, USA) for measuring the activity of cellular enzymes that reduce the tetrazolium dye to its insoluble formazan. Hernando, N. After the cells were incubated with the serially diluted GO or GO-Ag solutions for 1 h or 24 h at 37 °C, the enzymes were added into the treated cells to release the color from the cells. After 3 h of incubation, optical density can be measured at 500 nm using BioTek Synergy multi-detection microplate reader (BioTek, Winoosk, VT, USA), and CC50 can be calculated. All assays were performed in triplicate. Comparisons of results between GO and GO-Ag groups were analyzed using a t-test in the R program [25]. p-values of 4.

Discussion This is the first report investigating the antiviral activity of GO and GO-Ag against enveloped and non-enveloped viruses. Ag NPs have shown antiviral activity against enveloped viruses in previous studies, but no studies have discussed the antiviral activity of GO and GO-Ag. The antiviral mechanisms of Ag NPs are mainly based on the blocking of viral entry and the interference with viral membrane fusion [12,14]. The antiviral activity of GO-Ag observed in the current study should be contributed to by Ag particles on GO sheets. The sizes of Ag particles on GO sheets shown by FE-SEM images ranged from 5 to 25 nm, and about 50% of Ag particles were 10 nm or fewer than 10 nm. Less inhibition ability (25%) of GO-Ag (1 mg/mL) against coronavirus (47,000 TCID50/mL) was observed, compared to 97% of inhibition against influenza virus (100 TCID50/mL) by Ag NPs (0.05 mg/mL) [14]. However, the virus inhibition ability of Ag NPs in Xiang’s study [14] is not much better than that of GO-Ag in this study if we calculate the differences of virus and compound concentrations.

Since GO sheets also showed antiviral ability against the coronavirus in this study, the synergistic effect from GO sheets and Ag particles on the inhibition against the infection of an enveloped virus should be considered. No studies have been done on the antiviral activity of GO and GO-Ag but strong antibacterial activity has been observed in GO and GO-Ag. Exposure to GO and reduced GO can induce significant production of reactive oxygen species in Pseudomonas and lead to the fragmentation of bacterial DNA and death [17]. 2D ). From de Faria’s study, GO sheets showed no antibacterial activity, while GO-Ag had a 100% inhibition rate of the adhered cells, thus preventing the process of biofilm formation [16]. (Bottom) Two inner core protein VP3 conformers colored cyan and green. Its genome was sequenced in 1981.

Additionally, the immobilization of Ag NPs on GO sheets has reduced cytotoxicity, usually caused by free Ag NPs. Silver particles anchored on graphene oxide sheets (GO-Ag) can inhibit the infectivity of enveloped and non-enveloped viruses with very low to none cytotoxicity to cells susceptible to viruses. For non-enveloped viruses, graphene oxide (GO) sheets act as supporting materials for antiviral Ag particles without any antiviral ability. Sindbis (an alphavirus) is an enveloped, single-stranded RNA virus that is also used as a model for Hepatitis C Virus. GO sheets also show very low cytotoxicity to cells. In conclusion, this study discovered that GO and GO-Ag are novel materials for the further development of protective reagents and equipment against the transmission of infectious viruses. Because both enveloped and non-enveloped viruses can cause severe infectious diseases, we choose one to test GO and GO-Ag.

In consideration of strict regulation of BSL-3 pathogens and the dangers of handling, we chose feline coronavirus (FCoV) for the enveloped virus and infectious bursal disease virus (IBDV) for the non-enveloped virus, because no zoonotic transmission by them has ever been reported. Cells and culture medium were harvested at indicated time points. The protective effect of the N95 facemask was reduced significantly when the mask was moistened by accidental splashes of blood or body fluids from patients, or by sweat and respiratory droplets from the wearers. If the mask surface is contaminated with infectious agents, microorganisms may be able to penetrate the protective layers along with the droplets [27]. with minor modifications (39).