Most medical devices that are placed within the gastrointestinal tract have to be removed eventually. Such procedures can be challenging to perform and require anesthesia, with all its associated risks and costs. For example, thousands of bariatric balloons are deployed every year and each one of them has to be fished out a few months after positioning. Now, researchers at MIT have developed a way to make devices that go into the gut break up into many pieces when illuminated with light. This may allow for devices that don’t need removal and that can be triggered to come apart when a light emitting pill is swallowed. The technology depends on a light-sensitive hydrogel in which bonds break when blue or ultraviolet light (between 405 and 365 nanometers) strikes it. The soft hydrogel can be attached to other compounds, such as polyacrylamide, to make the final material strong and resilient when inside the body, but it can still come apart when illuminated. “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,” said Giovanni Traverso, the senior author of the study. The material was already tested in lab pigs and the researchers demonstrated that it does indeed work as desired and breaks up only when exposed to light at certain wavelengths. Since this approach is independent of other related factors such as pH levels or temperature, it prevents unwanted triggering. Moreover, the illumination doesn’t have to come in direct contact with the material, and so can be made to work at a distance. The new material can be customized to break up slower or faster and to react at different rates to different wavelengths of light. To demonstrate the technology in a real-world application, the MIT team created a novel seal for a bariatric balloon and an esophageal stent that do not require a removal procedure. The proof-of-concept prototypes showed that it should be possible to create such devices for safe use in humans. Source
