Researchers from the University of North Carolina at Chapel Hill, North Carolina State University and Changchun Institute of Applied Chemistry at the Chinese Academy of Sciences have developed a skin patch that measures blood glucose levels and releases insulin when levels climb too high. The team’s work testing the patch in mice was published earlier this month in ACS Nano.

People suffering with Type I diabetes don’t make insulin, while those with Type II can’t use insulin effectively. Both groups of patients are tasked with monitoring their blood sugar regularly using finger prick tests. Some patients inject themselves with insulin when their blood sugar fall to dangerous levels. But, even if a patient is closely monitoring their readings, their blood glucose levels can get out of control.

The collaborative team of researchers were hoping to develop a device that could manage diabetes in a simpler, more effective way.

The team’s skin patch is made up of biodegradable microneedles filled with tiny, insulin-carrying pouches that are engineered to break apart and release insulin in response to high glucose levels. The microneedles are made using a polymer that is loaded with glucose oxidase. When the glucose oxidase reacts with glucose, hydrogen peroxide forms and the needles disintegrate, releasing insulin into the bloodstream.

Mice with diabetes wearing the skin patch maintained level concentrations of insulin their blood. When the researchers administered a shot of glucose to the mice, their blood sugar levels spiked and then fell to normal levels within 2 hours.