Figure 2. In vitro expression of the NDV vaccine nanoparticles by western blotting. (A) In vitro expression of the pFNDV-PLGA-NPs in BHK cells. Lane 1: protein marker; Lane 2: the naked plasmid DNA groups; Lane 3: the plasmid DNA from pFNDV-PLGA-NPs transfected group; Lane 4: blank PLGA-NPs group; Lane 5: BHK cells group as the negative control; (B) In vitro expression of the pFNDV-CS-NPs in 293T cells. Lane 1: pFNDV-CS-NPs transfected group; Lane 2: naked plasmid DNA groups; M: Protein marker; Lane 3: 293T cells as the negative control; Lane 4: blank CS-NP group; (C) Detection of the NDV structural proteins after encapsulation by western blot. M: Protein marker; Lane 1: Original NDV fluid; Lane 2: NDV recovered from the NDV-CS-NPs. Four positive reaction bands were detected at 75 kDa (HN), 54 kDa (F), 45 kDa (P), and 41 kDa (M). Abbreviations: CS, chitosan; NDV, Newcastle disease virus; pFNDV-PLGA-NPs, the F gene of Newcastle disease virus encapsulated in PLGA nanoparticles; pFNDV-CS-NPs, Newcastle disease virus F gene encapsulated in chitosan nanoparticles; HN, hemagglutinin-neuraminidase protein; F, fusionprotein; P, phosphoprotein; M, matrix protein.