Effective intracellular delivery and Th1 immune response induced by ovalbumin loaded in pH-responsive polyphosphazene polymersomes

Protein antigen ovalbumin (OVA) was efficiently loaded into pH-sensitive PEDP polymersomes. Then OVA polymersomes were endocytosed by phagocyte cells and the antigen was digested to peptide by proteases in lysosomes. After being released to the cytosol, the peptide combined with MHC (Major Histocompatibility Complex) and the MHC/peptide complex was transported to surface of APC cells and then bonded with the relevant receptor of effector cells. Consequently, the Th1 immune response elicited by the advanced administrated OVA was strong enough to suppress the growth of tumor as a prophylactic vaccine.94