Cationic Nanostructures as Adjuvants for Vaccines

Spherical or discoidal lipid polymer nanostructures bearing cationic charges successfully adsorb a variety of oppositely charged antigens (Ag) such as proteins, peptides, nucleic acids, or oligonucleotides. This report provides instructions for the preparation and physical characterization of four different cationic nanostructures able to combine and deliver antigens to the immune system: (1) dioctadecyl dimethylammonium bromide (DODAB) bilayer fragments (DODAB BF); (2) polystyrene sulfate (PSS) nanoparticles (NPs) covered with one cationic dioctadecyl dimethylammonium bromide bilayer (DODAB) named (PSS/DODAB); (3) cationic NPs of biocompatible polymer poly(methyl methacrylate) (PMMA) prepared by emulsion polymerization of the methyl methacrylate (MMA) monomer in the presence of DODAB BF (PMMA/DODAB NPs); (4) antigen NPs (NPs) where the cationic polymer poly(diallyl dimethyl ammonium chloride) (PDDA) directly combined at nontoxic and low dose with the antigen (Ag); when the oppositely charged model antigen is ovalbumin (OVA), NPs are named PDDA/OVA. These nanostructures provide adequate microenvironments for carrying and delivering antigens to the antigen-presenting cells of the immune system.