Non-surgical implant uses laser light to treat obesity
While some folks might say that obese people should just exercise more and eat less, things aren't always quite that simple. With that fact in mind, a new implant is being designed to help boost the weight-loss process, by killing hunger-inducing cells in the stomach.
Ghrelin is a naturally produced hormone that stimulates the appetite, increases food intake and promotes the storage of fat. And while small amounts of it are released by the brain, pancreas and small intestine, most of it is produced and secreted by cells in the upper portion of the stomach.
Scientists at the Catholic University of Korea recently set out to reduce the activity of those cells, by modifying an existing prototype implant. Known as the "intragastric satiety-inducing device" (ISD), it consists of a stent which is non-surgically lodged in the lower esophagus, connected to a disc that rests in the opening to the stomach. A small opening in that disc allows food to pass through.
In the new version of the ISD, the underside of the disc is coated with an FDA-approved drug called methylene blue. Additionally, a fiber optic laser passes down through the opening in the disc, curving back around to point at its underside.
When the laser shines on the methylene blue, the irradiated drug responds by producing an energized form of oxygen known as singlet oxygen. That singlet oxygen kills nearby ghrelin-producing cells, then quickly disappears from the stomach. The implant is subsequently pulled back out of the body.
After young pigs had received the treatment for a period of one week, both their ghrelin levels and body weight gain were reduced by half, as compared to an untreated control pig. Those differences lessened over the following weeks, as the killed-off ghrelin-producing cells were naturally replaced – this means that for the hunger-suppressing effect to last, the light treatment would have to be periodically repeated.
Further research is now being performed, with an eye towards eventually testing the technology on humans.
A paper on the study – led by Hwoon-Yong Jung, Jung-Hoon Park and Kun Na – was recently published in the journal ACS Applied Materials & Interfaces.