Development of an oral nanovaccine for dogs against Echinococcus granulosus.

Dogs are the main source of animal and human cystic echinococcosis caused by the Cestode parasite Echinococcus granulosus. Dog vaccination seems to be a good strategy to control this parasitic disease. Here we present the development of a polymeric nanoparticle-based oral vaccine for dogs against Echinococcus granulosus delivered in enteric-coated capsules. To achieve our target, we encapsulated two recombinant antigens into biodegradable polymeric nanoparticles in the presence of Monophosphoryl lipid A as an adjuvant to ensure efficient delivery and activation of a protective mucosal immune response. The formulated delivery system showed a nanoparticle size less than 200 nm with more than 80 % antigen encapsulation efficiency and conserved integrity and immunogenicity. The nanoparticle surface was coated with chitosan to enhance adhesion to the gut mucosa and a subsequent antigen delivery. Chitosan-coated nanoparticles showed a higher cell internalization in murine macrophages and dendritic cells as well as a higher penetration into Caco-2 cells in vitro. Antigen-loaded nanoparticles were freeze-dried and enteric-coated capsules were filled with the obtained powder. The obtained results show a promising nanoparticles delivery system for oral vaccination.