MIT's ingestible medical devices can be dissolved by light
In search of advanced medical devices that can be ingested by the human body and don’t need to be surgically removed after, scientists at MIT have developed a new technology that would instead break them down by exposure to certain kinds of light. The research could help avoid the need for invasive endoscopic surgeries, with patients needing only to swallow an ingestible LED light to break down the device into biocompatible components for safe passage.
There are many scenarios where a medical device might need to be inserted into a patient's gastrointestinal tract to investigate or treat different disorders. A bariatric ballon, for example, can be used to treat obesity by inflating in patient’s stomach to suppress appetite and then removed after six or 12 months with endoscopic surgery. Esophageal stents are another example, used to combat a narrowing of the esophagus due to cancer or other conditions.
“We are developing a set of systems that can reside in the gastrointestinal tract, and as part of that, we’re looking to develop different ways in which we can trigger the disassembly of devices in the GI tract without the requirement for a major procedure,” says Giovanni Traverso, senior author of the study.
Traverso and his co-authors approached this problem by developing a new kind of light-sensitive hydrogel. The basis of the material is a polymer gel containing chemical bonds that can be broken apart by light in the blue to ultraviolet range. This polymer was combined with stronger components made of polyacrylamide to make it more durable, but still with the ability to be broken down by light on command.
The gel’s makeup can be tweaked to give it different capabilities. More use of the light-sensitive polymer in its construction means that it will break down faster, but is mechanically weaker. The amount of time needed to break down the material can also be controlled by the light source, with blue light working more slowly but offering better safety than ultraviolet light.
The hydrogel was tested out as a seal for a bariatric balloon, which was place inside pig stomachs and inflated. A small ingestible blue LED light was then placed in the stomach for six hours, causing the balloon to slowly deflate. The team reports that with a higher-power LED light, the material was broken down in 30 minutes.
In another experiment, the team successfully used its material to build an esophageal stent. As with the bariatric balloon seal, the idea is that once the tools have done their job, their breakdown can be triggered by light and they can be passed through the digestive tract once they are no longer required.
“This study is a proof of concept that we can create this kind of material, and now we’re thinking about what are the best applications for it,” Traverso says.
The research was published in the journal Science Advances.