Novel Hydrogel-Forming Microneedle Array for Intradermal Vaccination in Mice Using Ovalbumin as a Model Protein Antigen

Global vaccination strategies have traditionally relied on the hypodermic needle and syringe model. However, to facilitate increased immunization coverage and reduce costs, novel methods of vaccine delivery are warranted. Dissolving microneedle arrays (MNs) have been proposed as an alternative approach to the hypodermic needle, offering the prospect for self-vaccination and increased immunogenicity via direct targeting of skin dendritic cells. This study, for the first time, compares the use of novel hydrogel-forming MNs and dissolving MNs for the delivery of a model protein antigen ovalbumin (OVA). We provide comparative data on both MN types in terms of in vitro characteristics and in vivo immunogenicity. Herein, both MN platforms were tested and characterized in terms of mechanical integrity and insertion properties using a validated skin insertion model. A comparative in vivo vaccination study in BALB/c mice was conducted, whereby anti-OVA specific IgG was used as a measure of delivery efficacy and su...