Nanoparticle research, has the capacity to profoundly affect mankind’s future. By carefully researching nanoparticle elements into their smallest components and then engineering these particles to achieve different functions, researchers can dramatically enhance everything from delicate electronics to life-saving medical techniques.
However, critics warn that we need to test and re-test all the effects that various nanoparticles can have on the human body before releasing them in wide numbers as the main components of common products that will come into contact with humans several times a day. Given the latest in nanoparticle research for safety, they may be right.
Researchers at the University of Texas and the University of Ohio have recently discovered that carbon nanoparticles, both naturally occurring and engineered, can cause accelerated blood clotting in the human system. We come into contact with these minute particles of carbon in many ways, but one of the most concerning sources is fuel exhaust.
Because of its ability to spread easily through our air, each of us breathes in a significant amount of fuel exhaust every day, especially if we live in larger cities. And the fact that engineered carbon nanoparticles may have a blood-clotting effect worries doctors and scientists who want to use these diverse particles in the medical field to achieve positive results.
The Texas and Ohio researchers used anesthetized rats to test the nanoparticles’ thrombosis potential; they also ran a series of tests on human blood samples to ascertain whether the carbon particles had other effects and how these changed based on the formation of the particles.
They found that the same sets of carbon nanoparticle formation which triggered platelet clotting in the human blood samples also caused blockage of the carotid artery in rats, a condition also known as thrombosis or deep-vein thrombosis. The only exception was the C60 carbon formation, a spherical molecule of carbon that is sometimes called a fullerene or a “bucky ball” because of its shape. It had virtually no effect on the human blood platelets and very little in the test rats.
Marek Radomski, a professor at the University of Texas, wants to make it clear that his team and the associated university’s research group are not trying to discourage medical use of nanotechnology, since clearly the field will transform the practice of medicine in amazing, unprecedented ways.
He simply wants to emphasize the importance of knowing the new technology inside and out before letting it affect the human body so profoundly, and is trying to show nanotechnologists that there are good reasons to “assess the risk” and establish safety measures.
With nanotechnology growing so quickly, there are many people who will simply integrate it into their products in order to get a lucrative head-start in the marketplace. This happens quite frequently with new technology and it tends to leave regulation lagging behind. Radomski and his team are simply trying to insert a voice of caution into the nanotech feeding frenzy so that industry leaders will perhaps consider the human element ahead of their drive to make exorbitant profits.
Still, they are not by any means condemning nanotechnology—in fact, they had to use it in order to conduct this research. One of Radomski’s associates developed his own personal biological nanosensors so that he could track and measure the way the carbon nanoparticles affected the lab rats.
As a result, the team showed for the first time the specific ways in which nanotechnology could have harmful consequences. Up to this point, naysayers were considered mostly paranoid and didn’t have any concrete research to back their predictions.
The problem lies in nanoparticles’ extremely small size and flexibility. They are so tiny that they have no trouble whatsoever in passing discreetly through cell walls and when a human breathes them in, they quickly circulate through the lungs and get absorbed into the bloodstream, Radomski says, where they have a free shot at blood platelets.
These factors, combined with the carbon nanoparticles’ self-aggregating characteristics, make them very efficient at promoting human blood clots. And as we all know, this can cause artery blockage drastic enough to lead to a heart attack or a stroke and possibly death.
On a milder note, Radomski points out that nanoparticles of many kinds can be associated with the development of cardiovascular disease as well. These effects lie outside his area of expertise, but he knows enough about nanoparticles to know that they would be considered trace amounts in an air sample and possibly dismissed as harmless, despite their amazing ability to negatively affect human respiratory systems.
Radomski and his researchers went through a variety of possibilities when testing carbon nanoparticles, measuring the impact of mixed particles, single-wall nanotubes, standard urban matter, bucky balls or fullerenes, and multiple-wall nanotubes. In each case except for the fullerenes, the carbon nanoparticle formations caused significant platelet coagulation and rat thrombosis. The mixed carbon nanoparticles were the worst of the group, closely followed by single-wall nanotubes. Multiple-wall nanotubes and standard urban particle matter rated third and fourth on the damage scale.
They were also able to discover exactly how the carbon nanoparticles activate the platelets; apparently their innate chemical and physical properties interact with the blood clotting agents in such a way that they trigger their glycoprotein integrin receptor.
This platelet receptor affects their ability to clump together. Each nanoparticle set this receptor off in a slightly different way, but each one eventually sent the platelet receptor into overdrive, promoting extreme levels of unnatural clotting in the bloodstream. Blood flow in the rats’ carotid arteries became severely and dangerously restricted.
Nanoparticles have not become standard clinical practice as of yet, but it is anticipated that they will make their public debut sometime in the next 25 years. Nanoparticle research teams are highly hopeful that nanoparticles can be used to deliver site-specific anti-cancer drugs, thus revolutionizing and significantly improving the way we treat cancer. If, as this research suggests, those particles cause dangerous blood clotting, then they should be modified and made safe before doctors use them.