Meds that serve the purpose of thinning the blood may soon be taken out of the picture, thanks to the invention of a new vascular graft coating that releases an enzyme specifically targeting and destroying blood clots.

Cardiovascular problems are not uncommon and so neither are vascular graft and stent implants that open up narrowed blood vessels. But as in many other procedures and mediations, there is usually a drawback.

For vascular grafts, the procedure succeeds in restoring the flow of blood, but it leads to a problem: blood clotting.

To improve the results of vascular grafts and lessen the need for blood-thinning meds, scientists from the ITMO University in St. Petersburg, have devised a new type of artificial blood vessel coating that prevents the coagulation of blood known as thrombosis.

The research team, led by Vladimir Vinogradov from the International Laboratory of Solution Chemistry of Advanced Materials and Technologies, published its findings online in the Journal of Medicinal Chemistry.

The artificial blood vessel coating is a thrombolytic sol-gel layer with a nanoarchitecture that easily supplies the blood system with thrombolytic enzymes.

Aluminum oxide mixed with a urokinase-type substance that activates plasminogen makes up nanorods that are densely packed to form a thin film coating. Using the film to coat the interior of a vascular graft, the team was able to generate a concentration of the plasmin enzyme, stable enough to target blood clots.

Plasminogen is a substance that occurs naturally in the bloodstream. When it meets with plasminogen activators found inside the matrix of pores, the plasmin enzyme is produced, which acts against blood clots by dissolving them.

In the experiment, the researchers at the ITMO University conducted several tests to assess the properties of their film-coated vascular grafts. One of the tests involved artificial clots created from blood plasma combined with thrombin. When the team placed the artificial blood clots in the grafts for dissolving, they saw positive results.

"Our coating would destroy clots at the stage of formation, constantly ensuring an unobstructed blood flow in the graft," said the study's lead author Yulia Chapurina.