Microneedle Patches Could Improve Stability and Delivery of mRNA Vaccines

Microneedle-based vaccine patches could help address some of the formulation, storage, and administration challenges limiting broader deployment of messenger RNA (mRNA) vaccines, according to a review published in AAPS Open.

The review, authored by researchers including Lauren Levy, Chloe Tan, Yuting Huang, Xin Yang, Robert Langer, and Ana Jaklenec, examines how microneedle technology could improve vaccine stability, simplify administration, and support more consistent immunization schedules.

Although mRNA vaccines demonstrated their potential during the COVID-19 pandemic, widespread distribution remains complicated by temperature-sensitive formulations, cold-chain requirements, and the need for multiple doses. The researchers identify delivery and formulation engineering as important areas for addressing these limitations.

Microneedle patches offer an alternative to conventional injections by delivering vaccine formulations into the skin, where immune cells such as Langerhans cells and dermal dendritic cells can initiate immune responses. This approach may also reduce the amount of antigen needed to achieve protection while eliminating conventional needles and associated sharps waste.

The review highlights dissolving microneedle patches as a promising option for mRNA delivery. These devices use biodegradable, water-soluble polymers to encapsulate lipid nanoparticle-based mRNA formulations. Once applied, the microneedles dissolve in the skin, releasing their payload.

Researchers are investigating polymers including polyvinylpyrrolidone, polyvinyl alcohol, carboxymethylcellulose, and hyaluronic acid to protect sensitive mRNA formulations during storage and delivery. Studies from the Jaklenec laboratory indicate that optimized drying methods and excipient combinations can help preserve the biological activity of mRNA-loaded lipid nanoparticles under ambient and elevated temperature conditions.

Successful development will depend on balancing several formulation and manufacturing variables, including needle strength, dissolution rate, residual moisture, polymer composition, and mRNA stability. The authors emphasize the importance of quality-by-design approaches to ensure consistent manufacturing performance and reliable delivery.

While further development is needed, microneedle patches represent a potential platform for improving the stability, accessibility, and administration of next-generation mRNA vaccines.

Visit www.AAPS.org for more information.