Abstract:To prepare and investigate the recombinant Interferon-gamma (IFN-γ) nanosphere loaded in polybutylcyanoacrylate (PBCA) in Giant Panda (Ailuropoda melanoleuca), we firstly obtained the recombinant IFN-γ protein through prokaryotic protein expression technology, and then, by choosing PBCA as the drug delivery material, prepared the INF-γ PBCA nanosphere (IFNγ-PBCA-NS) using an emulsion polymerization method. Further more, the Kunming Mice (Mus musculus), which were infected with giant panda influenza virus A/Panda/Sichuan/01/2011 (H1N1), were used as models to test the efficacy of IFNγ-PBCA-NS compared to that of IFNγ after intragastric administration and subcutaneous injection of drugs. The results demonstrated that the molecular weight of INF-γ protein was about 33.5 ku, and the IFNγ-PBCA-NS was globular in appearance, with uniform particle size. The diameters ranged from 50 to 200 nm, the span was 0.55, the encapsulation efficiency of the particles was 56.7% and the drug loading was 0.86%. Moreover, the prolonged life rate of mice in the IFNγ-PBCA-NS group was significantly higher than that of the IFNγ group in both intragastric administration and subcutaneous injection approaches (P < 0.05 or P < 0.01). In summary, IFNγ-PBCA-NS showed better sustained release and antiviral activity in mice, which could provide references for further research on the preparation of the Giant Panda peptide drug microparticles.