The biggest problem that insulin-dependent diabetics have with treating their condition is the number of needle sticks they have to do each day. In tests in animals, the researchers showed that they could deliver enough insulin to lower blood sugar to levels comparable to those produced by injections given through skin.
The needle is spring-loaded - it is attached to a tiny compressed spring that's held in place by sugar.
"Our motivation is to make it easier for patients to take medication, particularly medications that require an injection", said senior author Giovanni Traverso. The material itself is nearly completely made from compressed, freeze-dried insulin. If that sounds a bit painful, worry not - your stomach wall has no pain receptors. Researchers crafted a miniature capsule with a similar shape and a weighted bottom, so that once it reaches the stomach it automatically rolls in the right direction to latch on, Traverso explained.
The researchers drew their inspiration for the self-orientation feature from a tortoise known as the leopard tortoise.
"Instead of liquid, we wanted to make it solid because you can fit a lot more in the pill in solid form than in liquid", said Dr Traverso. One key property of the new capsule is its ability to self-orientate, and its design is based on the leopard tortoise's shell with a high, steep dome to allow it to flip over. There is no indication of when the capsule might come to the commercial market.
"What's important is that we have the needle in contact with the tissue when it is injected", Abramson says.
When tested in pigs, the device worked consistently and was able to deliver equivalent doses of insulin to those required by someone with diabetes.
Once the tip of the needle is injected into the stomach wall, the insulin dissolves at a rate that can be controlled by the researchers as the capsule is prepared. The insulin needle takes about an hour to dissolve into the bloodstream.
Once the insulin was absorbed, the capsule, made of stainless steel and a biodegradable material, floated free and was excreted.
Once the contents from the capsule are released, it passes through the digestive system without any side effects.
The MIT team is now continuing to work with Novo Nordisk to further develop the technology and optimize the manufacturing process for the capsules. It may also work for nucleic acids such as DNA and RNA. He's from Brigham and Women's Hospital in Boston and the department of mechanical engineering at MIT in Cambridge, Mass. In addition to insulin, he said that the capsule system could likely be used to deliver drugs for other diseases.
Other authors of the paper include Ester Caffarel-Salvador, Minsoo Khang, David Dellal, David Silverstein, Yuan Gao, Morten Revsgaard Frederiksen, Andreas Vegge, Frantisek Hubalek, Jorrit Water, Anders Friderichsen, Johannes Fels, Rikke Kaae Kirk, Cody Cleveland, Joy Collins, Siddartha Tamang, Alison Hayward, Tomas Landh, Stephen Buckley, Niclas Roxhed, and Ulrik Rahbek.