A new study suggests that using nanocapsules to precisely target activated clotting platelets with clot-busting drugs could revolutionize the treatment of stroke and heart attack.
A report on the research, led by the University of Melbourne and the Baker IDI Heart and Diabetes Institute in Australia, is published in the journal Advanced Materials.
Joint senior author Christoph Hagemeyer, a professor in vascular biotechnology at Baker IDI, says their study shows what might be possible in the future from using nanotechnology to treat stroke and heart attack – a potentially revolutionary step.
For example, this life-saving treatment could be administered in emergencies by paramedics without the need for specialized equipment as is currently the case. Prof. Hagemeyer explains:
“We’ve created a nanocapsule that contains a clot-busting drug. The drug-loaded nanocapsule is coated with an antibody that specifically targets activated platelets, the cells that form blood clots.”
A blood clot or thrombosis is the result of a natural process of coagulation, where platelets and specialized molecules in the blood stick together to prevent excessive bleeding – at the site of an injury, for instance. One of the molecules that is central to this process is called thrombin.
Usually, the clots dissolve naturally after the injury has healed. However, sometimes clots can form inside blood vessels without an obvious injury, or they do not dissolve naturally.
If the clot forms in a coronary artery and blocks it, the result is a heart attack. If the clot forms in an artery supplying blood to the brain, it leads to a stroke.
Nanocapsule breaks open in response to thrombin at targeted clot site
The study uses nanotechnology to approach the problem of how to deliver clot-busting drugs to the precise location of the clot. This is important because if the drugs end up in the wrong place, they could trigger bleeding.
Nanotechnology is a new and growing field where scientists are developing new tools that manipulate nanometer-sized materials at the scale of individual cells.
In their paper, the researchers describe how they developed a nano-sized capsule that responds to thrombin by breaking open and releasing the enclosed clot-busting drug once it reaches the site of the blood clot.
“We are effectively hijacking the blood clotting system to initiate the removal of the blockage in the blood vessel,” Prof. Hagemeyer explains.
Every year, around 1.5 million Americans have a heart attack or stroke. In Australia, where the research was conducted, this figure can be up to 55,000. Co-senior author Frank Caruso, an engineering professor at Melbourne, notes that: “About half of the people who need a clot-busting drug can’t use the current treatments because the risk of serious bleeding is too high.”
He says that their targeted nanodrug, with its novel method of delivery, potentially offers a safer alternative with fewer side effects.
The National Heart Foundation of Australia, the Australian Research Council (ARC), and the National Health and Medical Research Council (NHMRC) funded the study.