We have drugs to treat nasty conditions like irritable bowel syndrome and Crohn's disease, but unfortunately their effects are often blunted by little stumbling blocks known as the stomach and the small intestine. These body parts are prone to absorbing certain medications before they can do their best work. But a new type of capsule holds onto its payload until reaching the large intestine, making for more effective delivery.

Researchers at Purdue University have developed what they are describing as a smart capsule. The device is around the same mass as a 000-size gelatin capsule and powered by a capacitor that is charged up before use. As the capsule makes its way through the body, an external magnet is applied when it reaches the ileocecal valve, a sphincter muscle valve at the intersection of the small and large intestines. This activates a spring-loaded mechanism that cracks the capsule open and releases the payload.

The team tested the capsule in an experiment involving a model that replicates the gastrointestinal tract and another that mimics the changing acidity and natural constriction/relaxation of our stomach as we digest food.

"It takes up to 12 hours to get to the large intestine, so we wanted to make sure the smart capsule can withstand conditions in the gastrointestinal tract," says Babak Ziaie, professor of electrical and computer engineering at Purdue.

The research team says the capsule could prove particularly valuable in treating Clostridium difficile, a bacterial infection that causes the body to lose microorganisms essential in fighting off infection. One method used to treat C. difficile involves transplanting feces from another person into the large intestine to provide it with the missing microorganisms. But by converting the microbes into powder and using the smart capsules to deliver them, treatment could a lot less invasive.

Having filed for a provisional patent for the technology, the researchers are continuing to develop the device with a view to moving to human trials.

You can see a video of the experiment below.

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