Inhibition Of Porcine Epidemic Diarrhea Virus By Silver Nanomaterials And Two-dimensional Materials

As the proportion of animal-derived foods in the modern diet grows,the food safety of animal-derived foods has recieved widespread attention globally.China is the largest country in pig breeding and pork consumption.With the improvement of health and safety awareness of modern consumers,the requirements for the safety and quality of raw pork and its products have become more and more strict.Porcine epidemic diarrhea（PED）is a contact intestinal disease caused by porcine epidemic diarrhea virus（PEDV）,and pigs carrying the pathogen pose a huge safety risk to the safe production of pork and its products.In recent years,a lot of researches have affirmed the safety and effectiveness of nanoformulations based on the unique physical and chemical properties of nanomaterials,which are worthy of further exploration and exploration in antiviral aspects.In this paper,we mainly used PEDV as a virus model to discuss red yeast-modified silver nanoparticles（RYR@Ag NPs）and composite two-dimensional nanosheet materials（GO-Mn O₂ NSs）of graphene oxide（GO）and Mn O₂ NSs nanosheets（Mn O₂ NSs）.（1）Red yeast rice（RYR）was ground and sieved,and the obtained RYR powder was used as reducing agent and modifier to synthesize RYR@Ag NPs with the better stability and biocompatibility by ultrasonic synthesis at room temperature.First,the morphologies were obtained by transmission electron microscopy（TEM）,UV-Vis Absorption Spectroscopy（UV-vis）,Fourier transform infrared spectroscopy（FTIR）,X-ray diffraction（XRD）patterns,X-ray electron spectroscopy（XPS）,etc.The cytotoxicity of RYR@Ag NPs on African green monkey kidney cells（Vero）was studied by MTT.The results demonstrated that the viability of Vero cells were above 90%after treatment with 11.63μM RYR@Ag NPs,indicating that RYR@Ag NPs have good biological properties.Then,The antiviral activity of RYR@Ag NPs was observed by indirect immunofluorescence experiments,Western Blot and virus growth curve,and the results showed that RYR@Ag NPs treatment at 11.63μM could inhibit the proliferation of PEDV.Finally,mechanistic study results showed that RYR@Ag NPs can inhibit the replication process of PEDV,it’s antioxidant activity can inhibit the excess ROS generated by virus infection and inhibit the cell apoptosis caused by virus infection,and can also induce up-regulation of the expression of cellular antiviral factors,meanwhile,it is found that the released Ag⁺plays a certain role in the antiviral effect of RYR@Ag NPs.（2）Two-dimensional composite nanosheet materials（GO-Mn O₂ NSs）were prepared by combining graphene oxide（GO）with Mn O₂ nanosheets（Mn O₂ NSs）throughπ-πstacking force.The morphology,structure,surface functional groups and element valences of GO-Mn O₂ NSs were characterized by TEM,UV-vis,FTIR,XRD,XPS,etc.The cytotoxicity and blood compatibility of GO-Mn O₂ NSs were studied by MTT and hemolysis experiment The results showed that GO-Mn O₂ NSs had good biocompatibility.The antiviral activity of RYR@Ag NPs was observed by indirect immunofluorescence,Western Blot and virus growth curve.The adsorption,replication and release processes of PEDV were inhibited.It can stimulate the expression of antiviral factors to inhibit virus infection,and at the same time,it has the effect of similar antioxidants to protect cells and inhibit cell apoptosis.