Nano Clot-Buster Targets Blockage

Nanotherapeutic sends clot busters to specific artery blockage

(RxWiki News) Clot-busting drug tissue plasminogen activator (tPA) is the only approved treatment for dissolving blood clots common during stroke, heart attacks or pulmonary embolisms.

However, the drug comes with bleeding risks and not all patients are candidates for this treatment. Hoping to improve treatment for blocked blood vessels, Harvard scientists have developed nanotherapeutics capable of targeting specific obstructed arteries.

Since the treatment targets a specific area, the dose is much smaller and carries fewer serious bleeding risks.

"Seek immediate medical attention if you suspect a blood clot."

Donald Ingber, MD, PhD, the Judah Folkman Professor of Vascular Biology at Harvard Medical School and Children's Hospital Boston, and professor of bioengineering at Harvard's School of Engineering and Applied Sciences, said that the nanotherapeutic, which is selectively activated in regions of high shear stress similar to living platelets, is an example of how biology can lead to unexpected solutions that can't be addressed by existing technologies.

The nanotherapeutic is capable of breaking apart and releasing the drug inside when it reaches a narrowed blood vessel.

During a pre-clinical study, researchers used the nanotherapeutic to treat mice with blocked lung vessels. Using a dose that was 50 times smaller than the dose typically given when administering tPA, investigators found that the mice had improved survival following the nanotherapeutic treatment.

The lower dose could make the therapy safer with a risk of fewer side effects.

The targeted therapy was inspired by the way blood platelets stick to the lining of narrowed blood vessels. This contributes to plaque build up, which can cause a blockage. As vessels constrict, high shear stresses cue circulating platelets to selectively adhere to the vessel walls.

The platelet-sized nanotherapeutic is activated by high shear stress, such as the stress caused by blood clot formation. The biodegradeable nanotherapeutic releases tPA-coated nanoparticles that bind to clots and degrade them when it detects it has reached as area with vascular narrowing.

Researchers suggest the therapy could some day be available to be administered in an ambulance en route to the hospital to anyone suspected of having a life-threatening blood clot.

The nanotherapeutics have not yet been used in clinical trials.

The study was recently published in journal Science.

Review Date: 
July 9, 2012