Scientists have found a new way to deliver mRNA medicines through the gut using tiny microneedles. The technique could one day replace some injections.

The study, published in ACS Nano, mapped where nanoparticles travel after microneedle injections in different parts of the gastrointestinal tract in mice. Different routes reached different organs.

For vaccines, the cheek worked best. Delivery to the cheek matched or improved the immune response of a traditional injection. That is because it targeted the lymph nodes.

For the pancreas, the stomach route was better. The team also delivered GLP-1 mRNA through the stomach. Blood sugar control improved in the mouse models. GLP-1 drugs treat obesity and diabetes.

“We could even potentially decrease the cost of those mRNA vaccines or mRNA drugs,” said researcher Ramy Ghanim. Changing the route may improve how the particles work.

The work is early and was done in mice. The team hopes to test more disease models and eventually move toward clinical use.