Researchers at the Koch Institute have created a blueberry-sized capsule that can be used to administer oral insulin doses. It can replace the injections that people with type 2 diabetes should give up every day.
Insulin is a peptide hormone produced by the β-cells of the pancreas. This enables the body to regulate the amount of glucose in the blood.
The new capsule is made of a biodegradable polymer. The internal microneedles components are quite complex: compressed, freeze-dried insulin and a biodegradable material and it is a lyophilized microparticle of insulin and a stainless steel spring that is rinsed and held in a sugar table. When sugar dissolves in gastric acid, the spring melts and pushes the microparticles into the stomach.
For people with type 2 diabetes, regular insulin injections are part of everyday life, but this is not the most convenient routine. Much work has been done to develop an insulin pill as a less invasive alternative, but it presents it’s own challenges. Now, an MIT team has developed a new design for a capsule containing insulin microparticles that inject the hormone through the stomach lining.
Oral administration of insulin may seem easy as the usual pills consist of too many medications. However, the stomach is a hostile environment and hard acids that can neutralize many compounds before they can get to work. Not surprisingly, the development of insulin pills has been largely applied to protective coatings that survive the journey until you can deliver the insulin load.
MIT researchers, however, have chosen a different approach. Several years ago, the team made a tiny needle-filled pill, which injected the drug into the case as it passed. Now the design has been refined to include only one needle, which injects the substance into the stomach, into the stomach.
Once the needle tip is inserted, the insulin dissolves in the blood at a constant rate. It took about an hour in this test, but researchers can change the frequency. Once the payload has been dispensed, the capsule passes through the digestive system without damage.
To make sure the needle touches and stays in the abdominal wall, the capsule has a tall, steep dome so it always turns on the flat side and rests where the needle comes out. According to the team, this design was inspired by the Leopard Turtle, with a uniform shell that allows it to stand up if it was ever on the back.
The team tested the New Capsule for Diabetes on pigs and found that 5 mg of insulin was effective in the animal’s blood. This is at a level comparable to that of regular insulin injection.
The researchers explain that the tests show that the method can be an effective alternative to insulin self-injections as well as to other treatments administered in the same way.
The research was funded by
- Novo Nordisk,
- National Science Foundation Graduate Research Fellowship,
- The National Institutes of Health,
- Brigham and Women’s Hospital,
- A Viking Olaf Bjork Research Scholarship, and
- The MIT Undergraduate Research Opportunities Program.