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 microspherescomposed 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 humoural 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.
- sub-unit vaccines
Kirby, D. J., Rosenkrands, I., Agger, E. M., Andersen, P., Coombes, A. G. A., & Perrie, Y. (2008). Liposomes act as stronger sub-unit vaccine adjuvants when compared to microspheres. Journal of Drug Targeting, 16(7-8), 543-554. https://doi.org/10.1080/10611860802228558