Frequent glucose monitoring is the name of the game when it comes to diabetes management. And for the 29 million Americans living with it, checking blood glucose levels is vital to their day-to-day health. Understanding highs and lows are integral in making sure a patient is on the right path with their diabetes management and medication, which can ultimately improve quality of life and may even save it.
According to Dr. Edward Chao, associate clinical professor of medicine at University of California San Diego School of Medicine and a physician at VA San Diego Healthcare System, testing blood glucose is something that patients routinely skip or avoid. He says a quarter of people receiving insulin treatment infrequently or never test their blood glucose.
This is why researchers at UC San Diego Jacobs School of Engineering and UC San Diego Center for Wearable Sensors hope a new tattoo sensor will make annoying finger-pricks a thing of the past.
The researchers, led by Joseph Wang, director of UC San Diego’s Center for Wearable Sensors and co-director, Patrick Mercier are developing a glucose monitoring patch that looks much like a tattoo. It is designed to monitor blood sugar levels without the discomfort of the finger-prick.
As Mercier explains in an article posted with UC San Diego News Center, “Just like a kid’s temporary tattoo, you apply it on the arm, dab with water and remove the back paper.” The tattoo, he explains, is printed with material containing two electrodes that apply a small amount of electrical current. “This forces glucose molecules that reside below the skin to rise to the surface, allowing us to measure blood sugar,” he says, “It’s safe and you can’t really feel it.”
The phase 1 clinical trial, headed by Chao, is taking place at UC San Diego Altman Clinical and Translational Research Institute. If approved, the researchers hope the sensor will help patients adhere to managing their disease better.
“Some patients struggle with self-monitoring of blood glucose with the lancets (finger sticks), and continuous glucose monitoring is often limited by cost and access issues, as well as it still requires a needle, the newest version doesn’t require calibrating with a glucometer, though,” Chao mentions.
The second challenge, Chao points out is carrying the supplies. “The meter, test strips, lancets, alcohol wipes – this is not discrete,” he adds. The cumbersome nature of checking blood glucose is another deterring factor for many patients with diabetes.
In regards to challenges in developing the tattoo sensor, Chao says the device worked well in those without diabetes, but there were difficulties getting accurate readings in patients with diabetes.
Four individuals were enrolled in a previous study. As of earlier this month, Chao indicates the study is using a revised protocol and one patient has completed testing with that protocol. “Originally, we were going to measure glucose in interstitial fluid, but technical difficulties led us to change that to checking [glucose levels] in sweat after administering topical pilocarpine to induce sweat.” He explains.
Pilocarpine is a medication that has been FDA-approved and is used clinically to induce sweating. The sensor will then measure the glucose level in sweat.
The idea of a prick-less blood sugar monitor isn’t new, and some devices are already on the market, for example, Abbot’s FreeStyle Libre Flash. However, Chao says the tattoo sensor different.
The Libre, he explains, uses a very fine filament and some patients report no discomfort whereas some do. “Our sensor would be non-invasive,” he says, “it would be completely needle-free, and would adhere to the skin.”
When asked whether the tattoo sensor could save lives, Chao remains cautiously optimistic. “This is speculating, but it can potentially contribute to this,” he says. Clinical trials