Nanoparticles may be able to damage the DNA of cells without ever coming into contact with it, according to a study published in the journal Nature Nanotechnology.
Nanoparticles are particles so small that they have fundamentally different physical and chemical properties than the same substances do at more familiar scales. Industry is increasingly adopting nanotechnology for a variety of applications, from consumer products to medicine, but the technology remains unregulated.
Researchers created particles of chromium and cobalt that were either four millionths (micro scale) or 30 billionths (nano scale) of a meter across, then placed them on a thin, artificial membrane composed of human cells. On the other side of the membrane, researchers placed human fibroblast cells, which are important components of connective tissue.
They found that although no particles crossed the cellular membrane, fibroblast cells placed across from the metal particles suffered DNA damage in 10 times as many locations and cells placed next to a membrane with nothing on the other side.
Researchers are unsure how the particles damaged the cells without crossing the membrane, but they believe they may cause changes in the membrane cells, which in turn signal the fibroblast cells and cause DNA damage.
"We used a variety of chemicals to block ... cell-to-cell signaling and found that in the presence of these blockers, the damage we were seeing was completely prevented," lead author Gevdeep Bhabra said.
The experiment was conducted with cobalt and chromium because both of those metals are currently used in medical implants. The researchers noted, however, that it would be unlikely for wear and tear to produce enough nano- or micro-sized particles to reach the concentrations used in the study. The implications of the study center more around the risks of actual nanotechnology.
Nanoparticles are already used in the manufacture of sunscreens, cosmetics, sporting goods and other consumer products. Researchers are also investigating their use as drug-delivery mechanisms.
Steve - we have alerted our clients about the lack of safety studies since we became aware of nanotechnology. To date, there is still very little. Federal regulators are way behind on this. So our suggestion is: any food or dietary supplement products that have anything "nano" on the label, avoid until safety can confirmed.