Preparation And Evaluation Of Piglet Pathogenic Diarrhea IgY And IgY Nanoparticle-in-microsphere

In this study,chickens were immunized by Enterotoxigenic Escherichia Coli(ETEC)Poricine epidemic diarrhoea(PEDV)and Poorcine transmissible gastroenteritis(TGEV)to get the Specificity IgY.To improve the stability of IgY and allow for a sustained release,we prepared anti-piglet diarrhea IgY nanoparticles-in-microsphere through the technology of Nanoparticle and microsphere.We also research the protective effect of IgY and IgY nanoparticles-in-microsphere on Diarrhea model of mice.Monitoring of antibody levels after the chickens were immunized by ETEC oil emulsion vaccine and blended oil emulsion vaccine of PEDV and TGEV,we found that there was no interference between this two vaccines and that the three kinds of antibodys could grow stably.Eggs with IgY were collected and separation and purification of IgY was done by water-dilution-method and NaCl.Pure IgY was abtained when the concentration of NaCl reached 1.5 mol/L NaCl and pH was 4.0,the purity was 93%and activity maintain more than 90%.IgY chitosan nanoparticles were prepared by using Ionic Crosslinking Method and were turned into microspheres through spray drying.Based on the drug loading and embedding ratio,with response surface methodology and central composite design to optimize the prescription,the optimum conditions for preparing IgY chitosan nanoparticles were:CS Concentration 2.37 mg/mL,CS/TPP(W/W)3.61:1,IgY Concentration 2.49 mg/mL.In such conditions,the embedding ratio,the drug loading and the average diameter of the chitosan nanoparticles were 53.28%?29.13%and 495.8 nm,respectively.Dry and uniform IgY nanoparticles were preparated by adjusting the parameter of spary drying and controlling the inlet air temperature at 175 0C and feeding speed at 30 mL/min.Under a electron microscope,IgY-NiSM appeared to be spherical particles,the embedding ratio and the drug loading were enhanced to 74.15%and 40.97%,their average size being 2300nm.The release rate of IgY-NiSM in SGF were only 8.82%for 2h,and The release rate in SIF were 70%for 4h,the relative activity of more than 55%,and it had protective effect on.IgY activity in high temperature.Effects of IgY and IgY-NiSMs were evaluated by establishing Escherichia coli diarrhea model of mice through clinical isolation of Escherichia coli.Results showed that IgY and IgY-NiSMs had obvious prevention effects in the diarrhea model mice.