A particularly unpleasant side effect of diabetes, especially if you’re squeamish, is having to inject yourself with insulin on a daily basis. Being able to administer insulin in an easier way, like swallowing a pill, would greatly ease the burden of patients with the condition.

Now, researchers at MIT have developed just that – so far, it’s only been trialed in animals, but it’s certainly an exciting start. They’ve created a small pill about the size of a blueberry that can be swallowed. It contains a tiny needle made of freeze-dried compressed insulin, which is released and injected into the stomach’s lining. If that sounds a bit painful, worry not – your stomach wall has no pain receptors.

A problem with swallowing insulin is that it gets broken down by stomach acid before it reaches the blood. Therefore, the researchers needed to ensure that their little insulin needles would only inject into the wall of the stomach, rather than randomly be released. So, they turned to an unlikely animal for inspiration: the leopard tortoise.

Leopard tortoises are found in Africa and have very cleverly designed shells. They are unusually high with steep sides, which comes in very handy if they roll onto their backs. The scientists used computer modeling to design their own version of a self-righting tortoise shell, creating a capsule that can orientate itself correctly, even in the stomach.

“If a person were to move around or the stomach were to growl, the device would not move from its preferred orientation,” Alex Abramson, first author of the study published in Science, said in a statement.

The needle is spring-loaded – it is attached to a tiny compressed spring that’s held in place by sugar. When the capsule reaches the stomach, this sugar dissolves, releasing the spring and the needle in turn. When the device was tested out on pigs, it took about an hour for all of the insulin to make its way into the blood and it didn’t cause any adverse reactions.

Currently, the pill can deliver the dose that someone with type 2 diabetes would normally have to inject, but more research and clinical trials are needed before the capsule can be given to real-life diabetes patients.

Insulin itself is a peptide, a short chain of amino acids, and the researchers say their device could be used to deliver other kinds of peptides too, such as immunosuppressant ones used to treat rheumatoid arthritis and inflammatory bowel disease.

“This is by far the most realistic and impactful breakthrough technology disclosed until now for oral peptide delivery,” noted Maria José Alonso of the University of Santiago de Compostela in Spain, who is not an author of the study.  

The researchers are now working on improving their capsule and determining how best to manufacture it.

“Our motivation is to make it easier for patients to take medication, particularly medications that require an injection,” said senior author Giovanni Traverso.

^{Diana Saville}