title: LUVs recovered with Chitosan: a new preparation for vaccine delivery.
abstract: Chitosan, alpha-(1-4)-amino-2-deoxy-beta-D-glucan, is a deacetylated form of chitin, an abundant natural polysaccharide present in crustacean shells. Its unique characteristics such as positive charge, biodegradability, biocompatibility, nontoxicity, and rigid linear molecular structure make this macromolecule ideal as drug carrier. The association between chitosan and liposomes was carefully described, where REVs (reverse phase evaporation vesicles) were sandwiched by chitosan. The usage of these particles in vaccine formulation is here proposed for the first time in the literature. The Chitosan-REVs now stabilized by polyvinilic alcohol were the vehicle for Diphtheria toxoid (Dtxd). Round chitosan-sandwiched REVs (REVs-Chi) particles of 373 +/- 17 nm containing 65% Dtxd were obtained. After 200 min of incubation in a simulated gastric fluid, 70% of the Dtxd was liberated from REVs-Chi in comparison to 100% of Dtxd liberated from pure REVs. In PBS, the Dtxd liberation from REVS-Chi was about 60%. Mice were immunized with Dtxd encapsulated within REVs-Chi and with other REVs/Dtxd formulations adsorbed onto Freund adjuvant or alumen [AIF and Al(OH)(3)]. The response patterns and the immune maturity were measured by IgG(1) and IgG(2a) titrations. REVs-Chi containing Dtxd elicited both antibodies production giving the animals higher immune response and selectivity. It was interesting that the memory of those mice immunized with REVs-Chi containing Dtxd enhanced, after booster, antibody production by 47% in contrast with 17 and 7% in mice immunized with the antigen vehiculated in REVs-AIF or REVs-Al(OH)(3), respectively.
authors.affiliation: Instituto de Materiales y Reactivos, Universidad de La Habana, Universidad de La Habana, Cuba.
authors.forename: Liliam Becherán
authors.initials: LB
authors.lastname: Marón
authors.forename: Carlos Peniche
authors.initials: CP
authors.lastname: Covas
authors.forename: Nadya Pesce
authors.initials: NP
authors.lastname: da Silveira
authors.forename: Adriana
authors.initials: A
authors.lastname: Pohlmann
authors.forename: Omar
authors.initials: O
authors.lastname: Mertins
authors.forename: Leonardo Nakamaru
authors.initials: LN
authors.lastname: Tatsuo
authors.forename: Osvaldo A B
authors.initials: OA
authors.lastname: Santanna
authors.forename: Ana Maria
authors.initials: AM
authors.lastname: Moro
authors.forename: Célia S
authors.initials: CS
authors.lastname: Takata
authors.forename: Pedro Soares
authors.initials: PS
authors.lastname: de Araujo
authors.forename: Maria Helena Bueno
authors.initials: MH
authors.lastname: da Costa
mesh_terms: D000818:Animals; D001672:Biocompatible Materials; D048271:Chitosan / Q000008:administration & dosage*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D008081:Liposomes; D051379:Mice; D008807:Mice, Inbred BALB C; D010316:Particle Size; D014612:Vaccines / Q000008:administration & dosage*
chemical_list: D001672:Biocompatible Materials; D008081:Liposomes; D014612:Vaccines; D048271:Chitosan