A Tattoo To Monitor Blood Sugar Levels May Not Be Far Off
Researchers at the Massachusetts Institute of Technology (MIT) are developing a new continuous glucose monitoring technology that will allow those with Type 1 diabetes check blood sugar levels using a glucose “tattoo.” The device has the potential to free people with diabetes from having to perform numerous finger pricks each day.
The glucose tattoo is made from a fluorescent nanoparticle ink injected under the skin that will reflect infrared light in response to glucose through the skin to a watch-sized monitor worn over the skin. The tattoo itself would only be a few millimeters in size and would not go as deep as a regular tattoo. The ink would likely last about six months before needing to be refreshed.
The nano ink particles are tiny spheres that consist of three parts: the glucose detecting molecule, a color-changing dye, and another molecule that mimics glucose. The three parts continuously move and when they approach the surface, the glucose detecting molecule either grabs a molecule of glucose or the mimicking molecule. If glucose levels are at a health level, the color is orange. If the detecting molecule mostly latches onto glucose (glucose levels too high) the ink appears yellow. If glucose levels are low, the ink turns purple.
The device is currently being tested in animals, and they do not yet know what side effects or allergic reactions might occur. “We are proceeding in a cautious way,” says senior researcher Michael Strano, an associate professor of chemical engineering at MIT. They are likely years away from human trials.
Another question is whether glucose levels in the skin would accurately reflect blood glucose levels. Some studies have shown that skin glucose levels can lag up to 20 minutes behind blood glucose levels. A current wearable glucose detection device, which works via an injection of an enzyme called glucose oxidase and an electrode placed on the skin is only approved for use for seven days at a time, is still not as accurate as finger-prick tests and must be recalibrated once or twice a day.
According to data from the CDC, 21.6 million people in the United States have diabetes. Approximately 5 to 10% of those cases are type 1, also called insulin-dependent diabetes mellitus (IDDM). People with type 1 diabetes do not make the hormone insulin that regulates blood sugar, so they must have insulin delivered by injection or a pump. To maintain normal glucose levels, patients must check blood sugar several times a day.
“Diabetes is an enormous problem, global in scope, and despite decades of engineering advances, our ability to accurately measure glucose in the human body still remains quite primitive,” says Strano. “It is a life-and-death issue for a growing number of people.”
May 27, 2010