University of Georgia researchers have developed a new technique to enhance stroke treatment. The new technique involves magnetically-controlled nanomotors that transport clot-busting drugs to remove life-threatening blockages in blood vessels.

Currently, recombinant tissue plasminogen activator (t-PA) is administered intravenously to patients following the diagnosis of ischemic stroke symptoms. The protein in the drug melts blood clots that cause strokes and other cardiovascular problems like pulmonary embolisms and heart attacks.

"Our technology uses magnetic nanorods that, when injected into the bloodstream and activated with rotating magnets, act like stirring bars to drive t-PA to the site of the clot," said Yiping Zhao, co-author of a paper and professor of physics in Franklin College of Arts and Sciences. "Our preliminary results show that the breakdown of clots can be enhanced up to twofold compared to treatment with t-PA alone."

Researchers tested the new technique on mice because the creature's blood clots are similar to that of humans'. They injected a mixture of t-PA and a small number of magnetic nanorods (only 300 nanometers in diameter) once the clot was formed.

One of the major side effects of t-PA treatment is uncontrolled bleeding. It temporarily prevents the formation of clots throughout the body, making patients susceptible to hemorrhage.

"We want to improve the efficiency of this drug, because too much of it can lead to serious bleeding problems," said Rui Cheng, paper co-author and graduate student in College of Engineering. "This approach may one day allow physicians to use less of the drug, but with equal or improved effectiveness."

The finding is published in the journal ACS Nano.