Soft, squishy device could potentially track ulcers, cancers, and other GI conditions over the long term.
MIT engineers have designed an ingestible, Jell-O-like pill that, upon reaching the stomach, quickly swells to the size of a soft, squishy ping-pong ball big enough to stay in the stomach for an extended period of time.
The inflatable pill is embedded with a sensor that continuously tracks the stomach’s temperature for up to 30 days. If the pill needs to be removed from the stomach, a patient can drink a solution of calcium that triggers the pill to quickly shrink to its original size and pass safely out of the body.
The new pill is made from two types of hydrogels — mixtures of polymers and water that resemble the consistency of Jell-O. The combination enables the pill to quickly swell in the stomach while remaining impervious to the stomach’s churning acidic environment.
The hydrogel-based design is softer, more biocompatible, and longer-lasting than current ingestible sensors, which either can only remain in the stomach for a few days, or are made from hard plastics or metals that are orders of magnitude stiffer than the gastrointestinal tract.
“The dream is to have a Jell-O-like smart pill, that once swallowed stays in the stomach and monitors the patient’s health for a long time such as a month,” says Xuanhe Zhao, associate professor of mechanical engineering at MIT.
In the lab, the researchers dunked the pill in various solutions of water and fluid resembling gastric juices, and found the pill inflated to 100 times its original size in about 15 minutes — much faster than existing swellable hydrogels.
The researchers further determined that a solution of calcium ions, at a concentration higher than what’s in milk, can shrink the swollen particles. This triggers the pill to deflate and pass out of the stomach.
Down the road, the researchers envision the pill may safely deliver a number of different sensors to the stomach to monitor, for instance, pH levels, or signs of certain bacteria or viruses. Tiny cameras may also be embedded into the pills to image the progress of tumors or ulcers, over the course of several weeks.
News Source: MIT
