This Wearable Patch Uses Sweat To Monitor Blood Glucose Levels

A dual-function patch for diabetes

People with diabetes prick their fingers multiple times a day to check their blood glucose levels, and dose themselves daily with injections of insulin. This monitoring is crucial, as rises in sugar levels in the blood can, over time, increase a diabetic patient’s risks of developing long-term complications from the disease. But this pricking and injecting can also be painful and tedious, making it harder for people to follow their doctor’s orders.

Over the past few years, researchers have been working on more convenient and less intrusive ways for people to monitor their diabetes. Now, a group of international researchers led by Dae-Hyeong Kim from the Institute for Basic Science in Seoul, South Korea have created a dual patch that can both monitor blood glucose levels and deliver medication that reduces high sugar levels when they occur. Their work was published today in Nature Nanotechnology.

How Does It Work?

The technology uses graphene, an extremely strong and flexible material made of carbon atoms and often used in wearable devices. In the past, scientists have used graphene to create similar patches, but certain properties of graphene have made it difficult to detect changes in sugar levels. To improve its abilities, the researchers in this study added gold particles and a surrounding gold mesh to the graphene.

When a diabetic person puts the patch on, the device captures sweat from the person’s skin. Sensors within the patch pick up on the sweat’s pH and temperature changes that signal a high glucose level. Once a high level is detected, heaters in the patch start to dissolve a layer of coating, exposing microneedles that then release a drug called metformin that can regulate and reduce high blood sugar levels. (If you’re curious, a microneedle injection would feel like either nothing at all or just a slight tingle.) Blood sugar readings are also wirelessly transmitted to a mobile device for the person to read and monitor.

The researchers researchers hope this combination of monitoring and drug delivery will help diabetics be able to better regulate the fluctuations of blood glucose throughout the day.

Next Steps

The researchers tested the patch on diabetic mice as well as two adult men with diabetes. In the future, before they can test the patch on more people, the researchers will have to scale up the drug delivery part of the device to inject human-sized doses.

In a news and views article that accompanied the paper, Richard Guy, a professor of pharmaceutical sciences at the University of Bath said that this patch has moved the field closer to the “coveted prize” of a non-invasive feedback system that combines monitoring and responsive drug delivery. However, he also acknowledged that more research needs to be done to answer key questions, including whether the device can stand up to increased sweat induced by vigorous exercise, whether the device can do this type of monitoring for a full 24 hours, and, most importantly, whether the drug delivery component can be scaled up and be able to deliver metformin “without an unfeasibly large number of microneedles and/or an unacceptably large patch.”

If the researchers can answer these key questions, this could mean a significant improvement in the health of diabetic patients.