Preparation Of Functional Nanomaterials And Their Antiviral Effects On Porcine Reproductive And Respiratory Syndrome Virus

The prevalence of virus not only seriously endangered human health,but also caused harmful pollution to the environment such as air,water and soil.The research of efficient virus inhibitors is of great significance for virus prevention.Functional nanomaterials have excellent biocompatibility and high antiviral activity,which has become one of the current research hotspots.Taking porcine reproductive and respiratory syndrome virus（PRRSV）as the model virus,we synthesized four functional nanomaterials（ZnS nanoparticles,FeS nanoparticles,carbon dots,two-dimensional MXene nanomaterials）and systematically studied the inhibitory effects of these nanomaterials on PRRSV proliferation.The specific research contents are as follows:1.Inhibitory effect of ZnS nanoparticles on PRRSVGlutathione modified ZnS nanoparticles（GSH-ZnS NPs）with an average size of 4.8 nm were synthesized from glutathione,sodium sulfide and zinc acetate.The inhibitory effect of GSH-ZnS NPs on PRRSV was systematically studied by virus plaque assay,western blot assay,indirect immunofluorescence assay and proteomic analysis.The results showed that GSH-ZnS NPs could not directly inactivate the virions but significantly inhibited the invasion and replication stages of PRRSV.When the concentration of GSH-ZnS NPs were0.90 mg/m L,its inhibition on the proliferation of PRRSV could reach 4 titers.Reactive oxygen species（ROS）imaging experiment showed that the concentration of ROS in infected cells decreased significantly after adding GSH-ZnS NPs.Proteomic analysis showed that GSH-ZnS NPs could inhibit virus proliferation by up-regulating VTN protein and down-regulating COX2 protein.Further studies showed that GSH-ZnS NPs had broad-spectrum antiviral effect on porcine pseudorabies virus,porcine epidemic diarrhea virus and vesicular stomatitis virus.2.Inhibition mechanism of ferrous sulfide nanoparticles on PRRSVGelatin modified FeS nanoparticles（Gel-FeS NPs）with an average size of 47.3 nm were successfully prepared by co-precipitation with gelatin,ferrous sulfate and sodium sulfide.Taking PRRSV as the model virus,the direct inactivation and inhibition effect of Gel-FeS NPs on PRRSV were systematically studied.The results showed that Gel-FeS NPs not only directly inactivate the virions outside the cell and inhibit the entry of the virus into the cell,but also inhibit the proliferation of the virus in the cell by releasing Fe（II）.The control experiment showed that FeS nanoparticles modified by carboxymethyl cellulose also had obvious inhibitory effect on PRRSV,while the antiviral effect of gelatin nanoparticles is not significant.It proved that ferrous sulfide nanoparticles and the released Fe（II）can inhibit the proliferation of PRRSV.The Gel-FeS NPs provide a new strategy for the development of new antiviral drugs,showing the prospects of Gel-FeS NPs for virus’s inhibition in the environment.3.Inhibitory effect of glycyrrhizic acid carbon dots on PRRSV proliferationGlycyrrhizic acid carbon dots（Gly-CDs）with good biocompatibility and antiviral activity were synthesized by one-step hydrothermal method using glycyrrhizic acid,an active ingredient of traditional Chinese medicine licorice.The effects of Gly-CDs on the proliferation of PRRSV were systematically studied.These results showed that Gly-CDs could directly inactivate the virions and significantly inhibit the invasion and replication of PRRSV.Gly-CDs could inhibit the proliferation of PRRSV by up to 5 titers at the concentration of 0.30 mg/m L.ROS imaging assay showed that the concentration of ROS in infected cells decreased significantly after adding Gly-CDs.Proteomic analysis showed that Gly-CDs could inhibit virus proliferation by up-regulating DDX53 protein and down-regulating NOS3 protein.In addition,Gly-CDs significantly inhibited other viruses such as PRV and PEDV,indicating the broad-spectrum antiviral activity of Gly-CDs.4.Inhibitory effect of MXene nanocomposites on PRRSV and SARS-Co V-2Using titanium aluminum carbide,chloroauric acid and sodium 3-mercaptopropane sulfonate as raw materials,two-dimensional MXene nanocomposites（Ti₃C₂-Au-MPS）were successfully prepared by hydrofluoric acid etching and surface modification technology.Taking two kinds of respiratory virus as the model virus which use heparan sulfate as the infection receptor,the antiviral activity of Ti₃C₂-Au-MPS on PRRSV and severe acute respiratory syndrome coronavirus 2（SARS-Co V-2）pseudovirus was systematically studied.After interaction between the Ti₃C₂-Au-MPS and PPRSV,Ti₃C₂-Au-MPS can directly inactivate the virions.The analysis of the process of virus infection showed that Ti₃C₂-Au-MPS can inhibit the adsorption and invasion stages of PRRSV infection.In addition,Ti₃C₂-Au-MPS can significantly reduce the expression of reporter genes GFP and luciferase in the SARS-Co V-2 pseudovirus,indicating that it has a strong inhibitory effect on the pseudovirus of SARS-Co V-2.It proved that the strategy of developing functionalized nanomaterials with the target ability to heparan sulfate receptors is effective for virus which use heparan sulfate as infection receptors was effective.We believed that our strategy will facilitate the development of new antiviral drugs and virus inactivation reagents in the environment.