Researchers from ITMO University, Russia, have developed artificial blood vessels that are not vulnerable to blood clot formation.
The team led by Vladimir Vinogradov, head of the International Laboratory of Solution Chemistry of Advanced Materials and Technologies managed to synthesize a thin film made of densely packed aluminum oxide nanorods blended with molecules of a thrombolytic enzyme.
Adhered to the inner surface of a vascular graft, the film forces the parietal area of the graft to get filled with a stable concentration of a substance, called plasmin. The substance is capable of dissolving the appearing clots.
"In order to test how our improved vascular graft worked, we grew an artificial clot made of blood plasma mixed with thrombin and placed it inside the graft. The results of the experiment amazed us. Very soon the clot started to dissolve and leak through the graft.
In reality, our coating would destroy clots at the stage of formation, constantly ensuring an unobstructed blood flow in the graft," said Yulia Chapurina, laboratory researcher and first author of the paper, who set up several in vitro experiments to demonstrate just how effective the film is.
The vascular grafts depend on drug-eluting technique, that is, they actively release medicine into the blood.
The lifetime of such grafts is often determined by the amount of drug stored within the graft.
The new system is based on the entrapment of the drug inside a porous protective shell, which makes the lifetime of such a graft practically unlimited.
"Our approach is concept-based and can be applied not only to artificial blood vessels, but to any kind of implants. You just need to take the right kind of drug. For example, after the implantation of an artificial ureter, urease crystals often start to grow inside and doctors do not know how to deal with this problem. It is possible to apply a similar drug-containing coating that dissolves urease. The same approach may be used for kidney or liver surgery, but these are plans for the future," says Vinogradov.