RMIT, MIT and Harvard identify drying conditions that protect vaccine

A study involving RMIT University, the Massachusetts Institute of Technology and Harvard Medical School identified conditions that protect particles carrying mRNA in dry microneedle vaccine patches.

The paper was published in Advanced Functional Materials and examined what happens when those fragile particles are dried into the dissolvable patch material.

Microneedle patches use hundreds of tiny tips to deliver vaccine into the skin as an alternative to standard injections.

Many mRNA vaccines need very low-temperature storage, which adds cost and complexity to transport and delivery.

That cold-chain burden can limit access in lower-resource settings. In 2024, 14.3 million children received no vaccines at all, according to the World Health Organisation and UNICEF.

Drying and rehydration tests

The team used advanced imaging and X-ray techniques to study mRNA-carrying particles before drying, during drying and after rehydration.

Those tests showed how the particles changed at each stage and which formulation conditions best preserved their structure and biological activity.

The study found that the design of the nanoparticles and the amount of polymer in the patch material both shaped how well the particles survived drying and re-dissolving.

Lead author Dr Brendan Dyett from RMIT said: “Many mRNA vaccines need to be stored at very low temperatures, adding cost and complexity to transport and delivery.”

Dyett’s team reported that the results explain how mRNA particles respond to drying and rehydration, giving practical guidance for future patch design.

The paper builds on earlier MIT-led research that showed the patches could be printed and stored at room temperature using a model mRNA system.

This study went further by explaining why some dry patch formulations perform better than others, combining RMIT materials characterisation, MIT microneedle and mRNA delivery work, and Harvard Medical School expertise in virology and immunology.

RMIT Distinguished Professor Calum Drummond AO said: “This research is helping build the foundation for microneedle patches that could make advanced vaccines and therapies simpler to use and easier to access.”

According to the researchers, the findings offer practical guidance for future dry mRNA vaccines and therapies that are easier to store, ship and use.