Developed by scientists from North Carolina State University and the University of North Carolina at Chapel Hill, the system incorporates porous hydrogel nanospheres.

Measuring about 250 nanometers in diameter, each sphere contains a drug/protein known as Y-27632 at its core, which is surrounded by a layer of another drug called tPA (tissue plasminogen activator). On the outside of each sphere is a coating of proteins that bind specifically to fibrin, a protein which is a key component of blood clots.

When injected into a vein, the nanospheres flow freely through the patient's bloodstream until encountering a clot, which they stick to. The tPA then proceeds to leak out, breaking down the fibrin and thus dissolving the clot.