Design Variation of a Dual-Antigen Liposomal Vaccine Carrier System

Abstract

The enclosed work focuses on the construction variables associated with a dual-antigen liposomal carrier, delivering encapsulated polysaccharides and surface-localized proteins, which served as a vaccine delivery device effective against pneumococcal disease. Here, the goal was to better characterize and compare the carrier across a range of formulation steps and assessment metrics. Specifically, the vaccine carrier was subjected to new methods of liposomal formation, including alterations to the base components used for subsequent macromolecule encapsulation and surface attachment, with characterization spanning polysaccharide encapsulation, liposomal size and charge, and surface protein localization. Results demonstrate variations across the liposomal constructs comprised two means of surface-localizing proteins (either via metal or biological affinity). In general, final liposomal constructs demonstrated a size and zeta potential range of approximately 50 to 600 nm and −4 to −41 mV, respectively, while demonstrating at least 60% polysaccharide encapsulation efficiency and 60% protein surface localization for top-performing liposomal carrier constructs. The results, thus, indicate that multiple formulations could serve in support of vaccination studies, and that the selection of a suitable final delivery system would be dictated by preferences or requirements linked to target antigens and/or regulatory demands.