title: Effects of extrusion, lipid concentration and purity on physico-chemical and biological properties of cationic liposomes for gene vaccine applications.
abstract: We developed cationic liposomes containing DNA through a conventional process involving steps of (i) preformation of liposomes, (ii) extrusion, (iii) drying and rehydration and (iv) DNA complexation. Owing to its high prophylactic potentiality against tuberculosis, which had already been demonstrated in preclinical assays, we introduced modifications into the conventional process towards getting a simpler and more economical process for further scale-up. Elimination of the extrusion step, increasing the lipid concentration (from 16 to 64 mM) of the preformed liposomes and using good manufacturing practice bulk lipids (96-98% purity) instead of analytical grade purity lipids (99.9-100%) were the modifications studied. The differences in the physico-chemical properties, such as average diameter, zeta potential, melting point and morphology of the liposomes prepared through the modified process, were not as significant for the biological properties, such as DNA loading on the cationic liposomes, and effective immune response in mice after immunisation as the control liposomes prepared through the conventional process. Beneficially, the modified process increased productivity by 22% and reduced the cost of raw material by 75%.
authors.affiliation: Departamento de Engenharia de Materiais e Bioprocessos, Universidade Estadual de Campinas, UNICAMP, Campinas, SP, Brazil.
authors.forename: Thais
authors.initials: T
authors.lastname: de Paula Rigoletto
authors.forename: Celio Lopes
authors.initials: CL
authors.lastname: Silva
authors.forename: Maria Helena Andrade
authors.initials: MH
authors.lastname: Santana
authors.forename: Rogério Silva
authors.initials: RS
authors.lastname: Rosada
authors.forename: Lucimara Gaziola
authors.initials: LG
authors.lastname: de la Torre
mesh_terms: D000818:Animals; D002412:Cations; D005260:Female; D005822:Genetic Vectors; D008055:Lipids / Q000737:chemistry*; D008081:Liposomes; D051379:Mice; D008807:Mice, Inbred BALB C; D014612:Vaccines / Q000737:chemistry* / Q000235:genetics
chemical_list: D002412:Cations; D008055:Lipids; D008081:Liposomes; D014612:Vaccines