A new stroke treatment that involves packing tiny magnetic nanoparticles with drugs and injecting them into the blood stream has been found to destroy clots in the brain 100 to 1,000 times faster than a commonly used clot-busting technique.
 

A study of the new approach involving human and mouse blood, reported in Advanced Functional Materials, suggests the new drug-delivery system may be a major step forward in preventing strokes, as well as heart attacks, pulmonary embolisms, and other dire circumstances where clots can cause severe tissue damage and death.
 

"We have designed the nanoparticles so that they trap themselves at the site of the clot, which means they can quickly deliver a burst of the commonly used clot-busting drug tPA [tissue plasminogen activator] where it is most needed," said researcher Paolo Decuzzi, who heads the Houston Methodist Research Institute Dept. of Translational Imaging.
 

Decuzzi's group coated iron oxide nanoparticles in albumin, a protein found naturally in blood that works like a sort of bio-camouflage, giving the drug-loaded particles time to reach their blood clot before the body's immune system attacks them.
 

Typically, a small volume of concentrated tPA is injected into a stroke patient's blood upstream of a confirmed or suspected clot. But it is not always effective in dissolving and clot and can be dangerous to patients who are prone to hemorrhage.
 

"Treating clots is a serious problem for all hospitals, and we take them very seriously as surgeons," said cardiovascular surgeon and study co-researcher Alan Lumsden, M.D. "Although tPA and similar drugs can be very effective in rescuing our patients, the drug is broken down quickly in the blood, meaning we have to use more of it to achieve an effective clinical dose. Yet using more of the drug creates its own problems, increasing the risk of hemorrhage. If hemorrhage happens in the brain, it could be fatal."