SINGAPORE: The fat-burning patch created by Nanyang Technological University (NTU) researchers is one of the latest patch technologies that researchers worldwide are studying to treat health issues.
A similar skin patch was also devised by US researchers to stimulate the body to produce insulin - potentially eliminating the use of needles for those with Type 2 diabetes, who rely on insulin shots to manage their blood sugar levels.
The experimental patch with soluble micro-needles was developed by National Institutes of Health’s (NIH) National Institute of Biomedical Imaging and Bioengineering (NIBIB), and is based on alginate, a gum-like substance extracted from brown algae, according to an online NIH article published on Dec 22.
“Alginate is a pliable material - it is soft, but not too soft,” said senior investigator Shawn Xiaoyuan Chen in the online article. “It has to be able to poke the dermis, and while not a commonly used material for needles, it seems to work pretty well in this case.”
The patch contains two drug compounds - exendin-4 and glucose oxidase - that interacts in the bloodstream to regulate blood sugar for days at a time. Exendin-4 is similar to a molecule the body produces in the intestine in response to food, and does not degrade in the bloodstream for more than an hour.
To control the rate the body absorbs exendin-4, which can cause nausea when too much is absorbed, the scientists combined exendin-4 with calcium phosphate to stabilise it.
The patch’s release of exendin-4 works this way: Rising glucose levels trigger exendin-4’s release. It then gets insulin flowing to reduce the glucose level, which slows down and stops the release of exendin-4.
“That’s why we call it responsive or smart release,” said Chen. “Most current approaches involve constant release. Our approach creates a wave of fast release when needed, and then slows or even stops the release when the glucose level is stable.”
In a study on mice, the researchers found that a half-inch patch could contain sufficient drug to control blood sugar levels in the mice for a week. The next step would be to test the patch on larger animals - and perhaps, using a larger patch to deliver a proportionately bigger dose of the drug. In addition to size, the micro-needles may need to be lengthened to penetrate human skin.
“We would need to scale up the size of the patch and optimise the length, shape, and morphology of the needles,” Chen said. “Also, the patch needs to be compatible with daily life, for instance allowing for showering or sweating.”
“This experimental approach could be a way to take advantage of the fact that persons with Type 2 diabetes can still produce some insulin,” said Professor Richard Leapman, NIBIB’s scientific director.
“A weekly micro-needle patch application would also be less complicated and painful than routines that require frequent blood testing.”