US researchers engineer smart capsule to target colon diseases

A new electronic drug capsule engineered to deliver medications directly to the colon could potentially offer a more effective and cheaper option for treating people with gastrointestinal conditions, according to researchers at Purdue University in Indiana.

The device is comprised of two parts, one carrying a drug payload and the other housing electronics designed on the same principles used to trigger a torpedo.

"There is a magnetic switch and so when it gets close to the magnetic marker that can be worn outside (the body) or can be implanted close to where you want to release it," said lead researcher Babak Ziaie.

"When it gets there it will trigger the magnetic switch and it will discharge the capacitor and you have a fuse that basically blows up," he added.

That reaction triggers a spring-loaded mechanism that separates the capsule and releases the medication.

The medication is released after the capsule makes its eight hour journey through the harsh acidity of the stomach and 20 feet of small intestine, ensuring its drug payload reaches the colon intact. The device tackles the complex problem of drug delivery to the lower part of the gastrointestinal tract.

The researchers designed the magnetic switch to ensure that electromagnetic signals such as those emitted by cell phones do not trigger capsule separation. Ziaie adds that the decision to wear or implant a magnet depends on a patient's weight.

"You have to be close. You have to be within a couple of centimeters. So for a lean person you can wear the magnet outside. But if someone is very obese it actually wont trigger from outside so you probably have to implant," he said.

This targeted drug delivery system could potentially make drug treatment for a variety of gastrointestinal disorders, including bacterial infections, Crohn's disease and Irritable Bowel Syndrome, more efficient and cheaper, according to Ziaie. He estimates his capsules could be manufactured "for cents" once scaled up to commercial levels.

The team is currently working with a private biomedical company in an effort to start clinical trials.

More than 20 percent of the people globally suffer from Irritable Bowel Syndrome, according to the International Foundation for Functional Gastrointestinal Disorders.