Modulation of Dendritic Cells by Lipid Grafted Polyelectrolyte Microcapsules

Polyelectrolyte microcapsules are fabricated by layer-by-layer deposition of dextran sulfate and poly-L-arginine layers at the surface of calcium carbonate template microparticles followed by core removal to produce hollow microcapsules. In the context of vaccination, these biodegradable LbL capsules emerge as promising antigen carriers and are believed to have potential for the co-delivery of antigens and immunomodulators associated within the same particle to enhance and steer the type of immune response. To this end, it is shown that LbL microcapsules can be functionalized at their surface with lipid layers containing immunopotentiators of lipid nature. The potency of the different lipid modified microcapsules to activate dendritic cells (DCs) is demonstrated by increased expression levels of the migration marker CCR7 and the maturation markers CD40 and CD86. Additionally, the DCs cytokine secretion profile is evaluated. The findings reveal that the lipid grafted microcapsules are superior to non-modified microcapsules in DC activation and suggest their potential as immune modulating antigen delivery systems.