Magnetically Controlled Nanorods could Help Treat Stroke

Magnetically controlled nanomotors can help transport clot-busting drug to dissolve life threatening blood clots, researchers say.

Researchers at University of Georgia say that the nanomotors can enhance stroke treatment.

Currently, recombinant tissue plasminogen activator, or t-PA is used to treat acute stroke. The drug is intravenously administered to the patients to patients showing primary signs of stroke. The drug dissolves the blood clots in the body that might cause stroke or heart attacks.

Researchers say that combining the drug plus the nanorods could lead to faster treatment of stroke. The nanorods are just 300 nanometers in diameter, by comparison human hair is about 80,000 to 100,000 nanometers wide.

The team tested the technique on mice.                                         

"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 the study and professor of physics in UGA's 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."

For the study, researchers used mice models that were genetically altered to have human-like blood clots. The team then injected the drug plus nanorods mixture into the mice.

According to the researchers, the nanorods -once inside the bloodstream- are activated by two revolving magnets, the magnets rotate like a small fan and push the drug to the site of the clot.

One of the major problems of using t-PA is that it temporarily inhibits the body's ability to clot blood. The new approach using the nanorods could help physicians use lower doses of the drug.

"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 UGA's College of Engineering. "This approach may one day allow physicians to use less of the drug, but with equal or improved effectiveness."

In a year, as many as 130,000 Americans die due to stroke, according to Centers for Disease Control and Prevention

The study is published in the journal ACS Nano