Radical Insulin Delivery Pill Inspired by Tortoise Shell
MIT researchers have developed an innovative drug capsule to deliver insulin that could one day replace the need for diabetes with type 1 diabetes to inject themselves. The small capsule contains a needle of compressed insulin that injects after the capsule reaches the stomach.
In tests conducted on animals, the pill worked to deliver insulin to lower blood sugar levels as well as a typical external injection. The researchers also say the capsule could be used to deliver other protein drugs.
“We are really hopeful that this new type of capsule could someday help diabetic patients and perhaps anyone who requires therapies that can now only be given by injection or infusion,” says Robert Langer, the David H. Koch Institute Professor, a member of MIT Koch Institute for Integrative Cancer Research, and one of the senior authors of the study.
Capusle is just as effective as injections
About the size of a blueberry, the capsule contains a small needle made of compressed insulin, which is injected after the capsule reaches the stomach.
In tests done on 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.
They also demonstrated that the device can be adapted to "deliver other protein drugs. The research follows on from a previous design of a tiny pill coated with many small needles. It was developed to inject drugs into the lining of the stomach or small intestine.
Clever design ensures correct injection location
The design of the pill has now been improved so that it has just one needle to avoid the pill being injected before it reaches the interior of the stomach.
The new pill’s single tip is made of almost 100 percent compressed, freeze-dried insulin. The needle is made in the same way an ordinary tablet is produced.
Within the capsule, the needle is attached to a compressed spring that is held down by a disc of sugar. Once the capsule enters the stomach, the sugar is dissolved by the stomach's water content, the spring is released and the needle is injected into the stomach wall.
The user of the capsule won’t feel any pain from the needle as the stomach has no pain receptors. The cleverest part of the design is the shape of the pill that ensures, no matter which way it lands the needle is always pointing towards the stomach wall.
Pill design inspired by nature
The pill has a self-orienting feature that its designers borrowed from the shape of a tortoise. The leopard tortoise has an unusual shaped shell that looks like a high dome, if the tortoise rolls over, the shape of its shells ensures it can always easily self-right.
The researchers made computer simulations of the pill inside the dynamic environment of a stomach to make sure the pill had the same self-righting feature.
“What’s important is that we have the needle in contact with the tissue when it is injected,” Abramson," said.
“Also, if a person were to move around or the stomach were to growl, the device would not move from its preferred orientation.” Almost 30 million Americans have diabetes.
Many instances of type 1 diabetes require patients to inject insulin daily. Daily injections can cause discomfort, the drugs require refrigeration, and they generate biohazard waste. These conditions mean that there is a significant number of patients that are not managing their disease adequate.
The researchers hope that their research can lead to an easier way of delivering insulin. “Our motivation is to make it easier for patients to take medication, particularly medications that require an injection,” " Traverso said.
“The classic one is insulin, but there are many others.”