(620ax) Microneedle Mediated Vaccine Delivery As a Platform to Modulate in Vivo Release Kinetics

Administering vaccines with hypodermic needles results in patient discomfort, hazardous waste, and the storage of these vaccine solutions in refrigeration systems while en route to their destination can be prohibitively expensive. Microneedles, which have been shown to deliver subunit vaccines to the immune cells in the dermis, are currently being studied as a means to circumvent the aforementioned issues. An additional advantage of using microneedles is that they can be designed to achieve sustained release kinetics. These designs include silk, polysaccharide, polymer blend, and particle-based microneedles, and their release profiles follow Fick’s law where the release rate is dependent on the amount of vaccine remaining within the implant. In contrast to these systems, we aim to design microneedles that exhibit exponential release kinetics since this would mimic how pathogen replication produces increasingly large quantities of antigen and Toll-like receptor ligands. We hypothesize that these microneedles that employ a degradable membrane fabricated with layer-by-layer techniques will elicit higher antibody titers than other microneedle designs and intradermal injections of the same antigen and adjuvant. These results could also provide a way to eventually generate even more complex release profiles, which could perhaps serve as both the prime and boost of a vaccine after administration with a single microneedle array.