Researchers at MIT have developed a new material that shows promise for use in ultra-long drug delivery systems, as well as electronic monitoring of the stomach and weight-loss intervention. A type of polymer gel, the material is flexible and pH-responsive, allowing it to reside in the stomach for long periods of time before safety dissolving in the small intestine.
The benefit of a single-use, long-term drug delivery method is significant, particularly for the patient, who doesn't have to deal with an ongoing routine of treatment. However, in reality, there are a number of problems that have hindered the routine use of such a device.
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First off, any potential solution needs to be small enough to comfortably fit down the esophagus (so that the patient can easily swallow it), but also has to be wider than the valve at the end of the stomach, known as the pylorus, so that it doesn't escape into the intestines. Furthermore, if it's to stay in the stomach for extended periods, the risk of intestinal obstruction is fairly high, and emergency surgery can be necessary to deal with the issue if it occurs.
The MIT-developed material, which is built from a combination of elastic and clinically utilized enteric polymers combined with hydrochloric acid, solves all of these issues.
The polymer is designed to be pH-responsive, meaning that while it's able to cope with the acidic environment found in the stomach, it dissolves in the near-neutral pH levels of the small intestine. This completely removes the risk of intestinal blockage. Its flexible nature also means that it's possible to compress and fold it into a capsule that's easy to swallow, expanding to a larger diameter than the pylorus (between 1.5 and 2 cm, or 0.6 and 0.8 inches).
The researchers fabricated several prototypes, including a ring-shaped device with a diameter of 3 cm (1.2 in) that's able to be folded into ingestible capsules. They tested the capsule in pigs, finding that the device expanded into its original shape within 15 minutes of swallowing, and remained in the stomach for around seven days. Once it passed out of the stomach, it was successfully dissolved in the small intestine.
Uses for a device constructed from the material include treatments for obesity, wherein a gastric-resident device helps control how hungry the patient feels, ingestible electronics that could be used to monitor various conditions, and of course, long-term drug delivery.
With regards to the latter of these uses, MIT is currently in negotiations with biotechnology company Lyndra to continue developing the technology for patient use, so it's reasonably likely we'll see the tech used in real life treatment somewhere down the line.
The researchers published the findings of their research in the journal Nature Materials.