title: Liposomes act as stronger sub-unit vaccine adjuvants when compared to microspheres.
abstract: The ability of liposomes and microspheres to enhance the efficacy of a sub-unit antigen was investigated. Microspheres were optimised by testing a range of surfactants employed in the external aqueous phase of a water-in-oil-in-water (w/o/w) double emulsion solvent evaporation process for the preparation of microspheres--composed of poly(D,L-lactide-co-glycolide) and the immunological adjuvant dimethyl dioctadecyl ammonium bromide (DDA)--and then investigated with regard to the physico-chemical and immunological characteristics of the particles produced. The results demonstrate that this parameter can affect the physico-chemical characteristics of these systems and subsequently, has a substantial bearing on the level of immune response achieved, both humoral and cell mediated, when employed for the delivery of the sub-unit tuberculosis vaccine antigen Ag85B-ESAT-6. Moreover, the microsphere preparations investigated failed to initiate immune responses at the levels achieved with an adjuvant DDA-based liposome formulation (DDA-TDB), further substantiating the superior ability of liposomes as vaccine delivery systems.
authors.affiliation: Medicines Research Unit, School of Life and Health Sciences, Aston University, Birmingham, UK.
authors.forename: Daniel J
authors.initials: DJ
authors.lastname: Kirby
authors.forename: Ida
authors.initials: I
authors.lastname: Rosenkrands
authors.forename: Else M
authors.initials: EM
authors.lastname: Agger
authors.forename: Peter
authors.initials: P
authors.lastname: Andersen
authors.forename: Allan G A
authors.initials: AG
authors.lastname: Coombes
authors.forename: Yvonne
authors.initials: Y
authors.lastname: Perrie
mesh_terms: D000276:Adjuvants, Immunologic / Q000008:administration & dosage*; D000818:Animals; D049109:Cell Proliferation; D016207:Cytokines / Q000096:biosynthesis; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D008081:Liposomes; D051379:Mice; D008807:Mice, Inbred BALB C; D008855:Microscopy, Electron, Scanning; D008863:Microspheres; D010316:Particle Size; D000644:Quaternary Ammonium Compounds / Q000008:administration & dosage*; D014612:Vaccines / Q000008:administration & dosage*
chemical_list: D000276:Adjuvants, Immunologic; D016207:Cytokines; D008081:Liposomes; D000644:Quaternary Ammonium Compounds; D014612:Vaccines; C015831:dimethyldioctadecylammonium