Titanium dioxide (TiO2) nanoparticles, found in everything from cosmetics to sunscreen to paint to vitamins, caused systemic genetic damage in mice, according to a comprehensive study conducted by researchers at UCLA's Jonsson Comprehensive Cancer Center.
The TiO2 nanoparticles induced single- and double-strand DNA breaks and also caused chromosomal damage as well as inflammation, all of which increase the risk for cancer. The UCLA study is the first to show that the nanoparticles had such an effect, said Robert Schiestl, a professor of pathology, radiation oncology and environmental health sciences, a Jonsson Cancer Center scientist and the study's senior author.
Once in the system, the TiO2 nanoparticles accumulate in different organs because the body has no way to eliminate them. And because they are so small, they can go everywhere in the body, even through cells, and may interfere with sub-cellular mechanisms.
The study appears this week in the journal Cancer Research.
In the past, these TiO2 nanoparticles have been considered non-toxic in that they do not incite a chemical reaction. Instead, it is surface interactions that the nanoparticles have within their environment- in this case inside a mouse - that is causing the genetic damage, Schiestl said. They wander throughout the body causing oxidative stress, which can lead to cell death.
It is a novel mechanism of toxicity, a physicochemical reaction, these particles cause in comparison to regular chemical toxins, which are the usual subjects of toxicological research, Schiestl said.
"The novel principle is that titanium by itself is chemically inert. However, when the particles become progressively smaller, their surface, in turn, becomes progressively bigger and in the interaction of this surface with the environment oxidative stress is induced," he said. "This is the first comprehensive study of titanium dioxide nanoparticle-induced genot
|Contact: Kim Irwin|
University of California - Los Angeles