Chemical “micromotors,” as illustrated here, can effectively deliver insulin in rats without an injection. Credit: Adapted from ACS Nano, 2022, DOI: 10.1021/acsnano.2c07953
Key points:
- Researchers delivered insulin to the colons of rats using an orally administered tablet powered by chemical “micromotors.”
- The key to the approach was actively moving the medicine around the body, before the robo-capsule could deliver its cargo.
- The team says the approach could work for other traditionally injection-only medications, as well.
In a new study, researchers show they have successfully delivered insulin to the colons of rats using an orally administered tablet powered by chemical “micromotors.”
Currently, insulin is only deliverable by injection—something doctors and researchers believe would change if the medication could be taken orally. But, the harsh environment of the stomach has been found to break down and neutralizes the hormone before it can be absorbed by the intestines and get into the bloodstream.
Scientists Yingfeng Tu, Fei Peng, Kun Liu and colleagues sought a better approach, one that relied on a robo-capsule to deliver its cargo by drilling itself into the thick, mucosal layer of the small intestine.
To make the tablets, the researchers covered magnesium microparticles with a layer of an insulin-containing solution and a layer of liposomes. They then mixed these particles with baking soda, pressed them into mini-tablets that were about 3 mm long, then covered them with an esterified starch solution. The starch protected the tablets from stomach acid, allowing them to reach the colon intact.
As they broke down, the magnesium microparticles reacted with water to generate a stream of hydrogen gas bubbles, which acted as micromotors that propelled insulin toward the colon’s lining to be absorbed.
When the team tested their mini-tablets in rats, they found that the pills significantly reduced the animals’ blood glucose levels for over 5 hours. In fact, the pills could maintain a glucose level almost as low as injection-delivered insulin.
Though more work is needed, the researchers say that this is a concrete step toward creating more oral formulations of not only insulin, but other traditionally injection-only medications.
Information provided by ACS.