Dissolving Microneedle Patches as Vaccine Delivery Platforms

Abstract

Microneedle (MN) patches overcome the drawbacks associated with parenteral route (risk of needle-prick injury, costly supervised administration, production of biohazardous waste) and deliver vaccines transcutaneously into general circulation. This study aimed to summarise three case studies relating to MN patch mediated vaccine delivery. Bacillus Calmette–Guérin (BCG), tetanus toxoid (TT) and rabies vaccine loaded patches were prepared using sodium alginate (SA), polyvinyl pyrollidone (PVP)/carboxymethyl cellulose (CMC) and PVP/hyaluronic acid (HA), respectively. MNs were evaluated for morphology, folding endurance, swelling and insertion ability. In-vivo immunogenic activity was assessed by recording several parameters e.g., immunoglobulin G (IgG), interferon gamma (IFN-γ), T-cell (CD4+ and CD8+) and rabies virus specific antibody count following MN patch application. MNs, displaying sharp tips and uniform surface, showed a folding endurance and swelling of ≥200 and ~70%, respectively indicating integrity and fluid uptake ability. MNs successfully penetrated into the skin simulant parafilm. MNs treated groups exhibited a significant increase in the IgG, IFN-γ, CD4+, CD8+, rabies virus specific antibody counts when compared to the control (untreated) groups and the results were comparable with standard intramuscular injection. Thus, MN patches can be used for transcutaneous vaccine delivery.

Keywords

• microneedle patches
• polymers
• transcutaneous delivery
• vaccines