Engineers at Massachusetts Institute of Technology have come up with a light-sensitive material that enables the creation of ingestible medical devices not requiring invasive procedures to remove.
Doctors often insert any of a number of different medical devices into the body, specifically the gastrointestinal tract, of patients. These help to diagnose, treat, or monitor disorders of this organ system, which takes food and breaks them down for the body’s use.
Endoscopic surgery is often needed to remove these devices from the body after they have served their purposes.
Now, MIT engineers have made a hydrogel that can be used in ingestible medical devices. This makes it possible to remove them using light and significantly reduces the need for endoscopic procedures.
According to the researchers, blue or ultraviolet light produced by a small LED caused devices made with this material to break down in pigs.
“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 senior author Giovanni Traverso, an assistant professor of mechanical engineering and a gastroenterologist at Brigham and Women’s Hospital.
The new paper appeared in the journal Science Advances.
A light-based approach
Traverso and Robert Langer, the David H. Koch Institute Professor, have been involved in the development of ingestible GI devices for years. At the same time, they have investigated different approaches for safely breaking them down in the body.
In this study, the research team explored the possibility of removing these devices using light. Traverso and Langer thought this offers certain benefits over other methods.
Ritu Raman, the lead author and a postdoctoral fellow at Langer’s MIT Lab, developed the hydrogel for this research. She based it on the previous work by former Langer lab postdoctoral researcher Kristi Anseth, now a chemical and biological engineering professor at the University of Colorado Boulder.
The polymer gel features a chemical bond that breaks down when exposed to a wavelength of blue to ultraviolet light – from 405 to 365 nanometers.
Rather than rely on the material singly, Raman used it to bond more robust parts, such as polyacrylamide, together. This made the resulting material strong enough to function properly, yet still degradable from light exposure.
The properties of the material make it possible for engineers to alter light sensitivity as desired. They could make the material to break down faster or slower.
Light-sensitive, degradable devices
The MIT engineers demonstrated two of the material’s use cases. They used it for bariatric balloons and for an esophageal stent.
Bariatric balloons, which are inflated in the stomach of a patient, are commonly used for the treatment of obesity. Doctors remove them around six months after insertion by the means of endoscopic surgery.
As for an esophageal stent, they help to treat esophageal narrowing as a result of a disorder, including cancer.
The research team tested light-sensitive balloons in pigs. The devices featuring latex and sodium polyacrylate quickly swelled on reaching the stomach of the animals. A small LED emitting blue light was then used to deflate the balloons.
The higher the intensity or power of the light, the faster the devices broke down, the researchers observed.
Also, the team designed an esophageal stent made with the light-sensitive material. It stated that this could be triggered with light to break down and then be eliminated from the GI tract.
Traverso said that this was a proof-of-concept study. The next step is to determine the best ways the material can be used.
The approach shows more potentials than the two applications demonstrated in this research. It could also be used to create other devices for delivering drugs to the GI tract, the team stated.
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