Preparation and evaluation of peptide-PLGA nanoparticles on porcine epidemic diarrhea virus infection

Abstract Background Porcine epidemic diarrhea virus (PEDV) can cause diarrhea, dehydration and death in suckling piglets, which seriously affects the economic benefits of the production line. Therefore, it is urgent to find an economical and effective treatment to prevent and control PEDV. Methods peptide (P6), which could specifically target the S1 C-terminal domain (CTD) protein of porcine epidemic diarrhea virus (PEDV), was subsequently conjugated to poly (lactic-co-glycolic acid) (PLGA) by dehydration synthesis generating P6-PLGA nanoparticles and used cell counting kit-8 (CCK-8), real-time fluorescence quantitative PCR (qRT-PCR), Western blot and indirect immunofluorescence to further study the inhibitory effect of different concentrations of P6-PLGA nanoparticles on PEDV. Results The results showed that cell viability was > 95% when treated with P6-PLGA nanoparticles at concentrations not exceeding 1000 µg/ml. Results of the absolute quantitative PCR revealed that the concentration of P6-PLGA nanoparticles at 400 µg/ml could significantly reduce the viral load of PEDV compared with the virus group (p < 0.05 or p < 0.001). Similarly, results of Western blot and indirect immunofluorescence also suggested that the antiviral effect of P6-PLGA nanoparticles at 400 µg/ml is still significant. Based on the above research, high affinity peptide (P6) was covalently coupled with PLGA particles to obtain P6-PLGA nanoparticles. Conclusions PLGA as a drug delivery carrier combined with peptide (P6) can overcome the problems of poor stability, easy degradation or low bioavailability of peptide after entering the body, and provide a new strategy for the development of PEDV antiviral drugs.