A new smart patch from North Carolina State University, Raleigh, NC, precisely releases blood-thinning drugs as needed. The device monitors a patient's blood to prevent thrombosis, the occurrence of blood clots.

Current thrombosis treatments often rely on the use of blood thinners like the drug Heparin, which require patients to test their blood on a regular basis in order to ensure proper dosages.

“Our goal was to generate a patch that can monitor a patient’s blood and release additional drugs when necessary; effectively, a self-regulating system,” says Zhen Gu, associate professor at NC State and UNC, and co-corresponding author on a paper describing the work.

The patch incorporates microneedles made of a polymer that consists of hyaluronic acid (HA) and Heparin. The polymer responds to thrombin, an enzyme that initiates clotting in the blood.

When elevated levels of thrombin enzymes in the bloodstream come into contact with the microneedle, the enzymes break the specific amino acid chains that bind the Heparin to the HA, releasing the drug into the blood stream.