A team of British researchers is raising new and serious questions about the health risks posed by nanoparticles.
The infinitesimal particles are at the core of a burgeoning new industry that has scores of businesses lining up outside laboratory doors, eager to apply nanotechnology to commercial projects, from cosmetics to antibacterial clothing to targeted delivery of pharmaceuticals.
But many scientists have raised serious questions about the health and environmental dangers posed by nanoparticles and the British study could elevate those concerns to a new plane. However, other researchers insist the conclusions are off-base an dnot relevant when assessing human health risks.
Vital organs and systems in the human body are protected by specialized barriers. The blood-brain barrier, for example, blocks the release of large molecules and other substances from the blood stream into cerebrospinal fluid.
The British scientists – Patrick Case and 15 other researchers from the University of Bristol – studied the ability of nanoparticles to penetrate past such barriers.
What they found was that nanoparticles used medically to target the delivery of drugs against cancer and other diseases can damage the DNA of cells without actually crossing the cellular barriers in the body.
This opens a very wide door to new safety concerns.
The study, conducted on cells grown in culture, suggests that the indirect effects of nanoparticles on cells should be weighed when evaluating their safety.
In an abstract of the study published online this week in Nature Nanotechnology, the researchers reported that the nanoparticles did not pass through the barrier to cause the DNA damage, but in fact generated molecules within the barrier cells that were then transmitted to the cells behind the barrier.
The amount of DNA damage in the cells behind the protective barrier was similar to the DNA damage caused by direct exposure to the nanoparticles.
Almost two decades ago, when French cosmetic designers were the first to use nanosized material in face powers and creams, some skeptics raised concerns about the nanomaterial entering the blood system and eventually passing into the brain.
Scientists for the cosmetic said the brain-blood barrier would prevent such contamination. Perhaps, based on Case’s work, that issue deserves another look.
It didn’t take long for Case’s study to draw criticism from other scientists that faulted its conclusions and side the word of the British team had little relevance to human exposure risk. .
Here is a link to a critical article in Science Now.