Inhibition Research Of Iron Sulfide Nanoparticles And Sulfur Quantum Dots On The Proliferation Of PRRSV

The application of nanomaterials in antiviral field is one of the research hot topic in recent years.Previous researches showed that several kinds of sulfides such as silver and zinc sulfides had good antiviral activity.However,it is still unclear whether other sulfides and sulfur nanomaterials had antiviral activity.On the basis of the synthesis of ferrous sulfide nanoparticles(FeS NPs)and sulfur quantum dots(SQDs),the photostability of SQDs was studied.Using porcine reproductive and respiratory syndrome virus(PRRSV)as a model of virus,the inhibitory effects of two functional nanomaterials on PRRSV were explored.The contents are as follow:1.Gelatin,ferrous sulfide and sodium sulfate were used as raw materials to synthesize FeS NPs modified with gelatin(Gel-FeS NPs)by chemical coprecipitation method.And several technologies such as transmission electrons microscope(TEM)and Fourier transform infrared spectroscopy(FTIR)were used to characterize Gel-FeS NPs.The results showed that as-prepared Gel-FeS NPs had good aqueous dispersibility and chemical stability with average diameter of 77.7 nm.Then the indirect immunofluorescence assay(IFA),western blot assay and plaque experiments were performed to evaluate the antiviral activities,and the results proved that Gel-FeS NPs inhibited the proliferation of PRRSV.Further research found that Gel-FeS NPs inhibited the proliferation of the PRRSV by inactivating the virus directly and inhibiting the adsorption or invasion process of virus.Comparing with the antiviral effects of the synthetic raw materials of Gel-FeS NPs,it was found that only Fe²⁺could inhibit the proliferation of PRRSV.The iron content inside and outside the cells infected with PRRSV and treated with Gel-FeS NPs was measured,respectively.It was found that the iron content outside the cells was much higher than that inside the cells.The research results provided a reference for the study of FeS NPs as a new type of PRRSV inhibitor.2.Polyethylene glycol-400 and glycyrrhizic acid were used as passivation agents to synthesize polyethylene glycol or glycyrrhizic acid modified sulfur quantum dots(PEG-SQDs,Gly-SQDs).The characterization results of TEM and fluorescence spectroscopy(FL)showed that both two functionalized sulfur quantum dots had good dispersion in aqueous solutions and stable fluorescence properties,and the average sizes were 6.8 and 6.5 nm,respectively.Then the photostability of PEG-SQDs was investigated by under different Xenon lamp irradiation time and pH conditions.It was found that the fluorescence intensity of PEG-SQDs gradually decreased with the prolongation of the light time.The PEG-SQDs had better photostability at pH 3.0 than that at pH 7.4 and pH 11.0.In addition,it showed that dissolved oxygen played an important role in the photostability of PEG-SQDs.The cytotoxicity influences of PEG-SQDs and Gly-SQDs were tested by MTT assay,and the results showed that both had good biocompatibility.Comparing the inhibitory effects on PRRSV proliferation,it was found that only Gly-SQDs can effectively inhibit the proliferation of PRRSV.Comparing with glycyrrhizic acid,Gly-SQDs had lesser cytotoxicity and better antiviral activates,which provided a reference for increasing the application of SQDs in the antiviral field.