Intradermal vaccination via electroosmotic injection from a porous microneedle patch

The feasibility of the electroosmotic flow (EOF)-promoted intradermal vaccination via a porous microneedle (PMN) has been demonstrated by in-vitro and in-vivo experiments with mice. The EOF-promoted directional transport of ovalbumin (OVA) through a negatively charged PMN was quantitatively evaluated by experiments using a side-by-side Franz cell. The preloading of the OVA solution into a PMN chip and its effective injection into mouse skin pieces were examined by microscope observations. By using mice, the immunological effect of the PMN-based intradermal vaccination has been proved by ELISA analysis of serum OVA-specific immunoglobulins (IgG1 and IgE). Although the passive diffusion-based release of OVA from PMN was too slow for effective vaccination, the EOF-assisted injection was found to be fast enough to effectively induce production of immunoglobulins.