Nanotechnology - in my toothpaste...?

(Nanowerk Spotlight) Imagine a toothpaste that not only seeks out but actually repairs damage to tooth enamel. For those who dread their annual visit to the dentist, this may sound like science fiction. For people in Japan, it is a reality. Using nanoparticles, Japan’s Sangi Company, Ltd., has sold more than 50 million tubes – and continues to expand its line of products containing nanoparticles. Scientists have learned to synthesize hydroxyapatite, a key component of tooth enamel, as nanosized crystals. When nano-hydroxyapatite is used in toothpaste, it forms a protective film on tooth enamel, and even restores the surface in damaged areas. Availability of similar products that claim to actually repair cavities is just around the corner.
Nanotechnology toothpaste
Toothpaste is among consumer products that contain nanoparticles (Image: Stockphoto)
Unlikely as it seems at first blush, the $200 billion global cosmetics industry is one of the major players in the emerging field of nanotechnology. According to the Centre for the Study of Environmental Change at Lancaster University in Britain, the cosmetics industry already holds the largest number of patents for nanoparticles – and be it toothpaste, sunscreen, shampoo, hair conditioner, lipstick, eye shadow, after shave, moisturizer or deodorant, the industry is leading the way.
One reason for this is the extremely marketable area of anti-aging products. In 2004, the market for these youth-promising skin care treatments was estimated at US$9.9 billion worldwide. New advances via nanotechnology are expected to drive that number up significantly. Take L’Oreal, which ranks sixth among nanotechnology patent holders in the U.S., with nearly 200 nanotechnology patents according to Boston-based UTEK-EKMS, Inc. The cosmetics giant has developed a polymeric nanocapsule which guides active ingredients into the lower layers of skin, increasing their efficacy. Although these fountain of youth products may be the most marketable and most lucrative, L’Oreal and its competitors are also introducing nanoproducts that have been engineered to produce dramatic results of a different sort, such as eye shadow with more vivid colors and iridescent or metallic effects.
For years, the cosmetics industry has made a great deal of money by marketing beauty products. People want these items and cosmetics companies provide them – simple supply and demand. The problem with nanoengineered products is that no one really knows whether they are safe.
Nanoparticles can assume very different chemical, physical and biological properties than their normal-sized counterparts. This, coupled with the fact that these tiny particles can be absorbed through the skin or inhaled, is causing significant concern about the safety of nanoparticles, particularly those used in everyday cosmetics.
Although there is no definitive evidence that nanocosmetics pose a health hazard, preliminary studies indicate there may be significant risk of nanoparticles passing through the skin, into the bloodstream, and accumulating in tissue and organs. It is believed that healthy skin provides an adequate barrier against particle absorption; however damaged, and even flexed, skin may allow particles to enter the body.
A group of researchers led by the Neurotoxicology Division at EPA’s (Environmental Protection Agency) National Health and Environmental Effects Research Laboratory in the U.S. have studied the effect of titania (titanium oxide nanoparticles) in mouse cells. The researchers reported ("Titanium Dioxide (P25) Produces Reactive Oxygen Species in Immortalized Brain Microglia (BV2): Implications for Nanoparticle Neurotoxicity") that the nanoparticles, which are currently used in sunscreen products, alter the cells’ normal response to foreign particles. Rather than releasing a burst of chemicals – reactive oxygen species (ROS) – to protect the brain, the nanoparticles induce a slower release of ROS, which could be potentially damaging to other brain cells. Other studies have shown similar results in fish. There is no data to confirm that this type of oxidative stress could damage neurons, but further investigation is already suggesting that titania may trigger cell death in neurons.
Although this is one of more than 350 safety studies ("Calls Rise for More Research on Toxicology of Nanomaterials") currently underway at labs and academic institutions around the globe, scientists stress that these results are preliminary and much more research must be done before an answer is found. In an article published in Science ("Toxic Potential of Materials at the Nanolevel"), researchers at UCLA concluded that although it is possible that engineered nanomaterials may create toxic effects, there is little evidence to suggest the effects will cause a significant problem that cannot be addressed by a rational, scientific approach. Although confident in science’s ability to ensure the safety of nanomaterials, these scientists also urge an immediate and proactive approach to safety – which so far, hasn’t happened in a large-scale and coordinated way.
In the meantime, numerous cosmetics containing nanoparticles are already on the market, and more are being introduced. A recent inventory study found more than 270 nanotechnology products already on the market in 15 countries; many of those were cosmetics. These 270+ products may present a fairly accurate picture of the market – or they may represent only a small fraction of what’s really out there.
Because the cosmetics industry is largely unregulated and cosmetics manufacturers are not required to provide product labeling, many people may be exposing themselves to the safety uncertainties of nanoparticles without knowing it. At this point, consumers can base their purchasing decisions only on advertising claims. And, while nanotechnology is a popular buzzword in marketing, not all products containing nanoparticles advertise their presence.
The lack of information about the safety of nanoparticles has generated concern among leading international regulatory agencies. In the U.S., the Food and Drug Administration (FDA) is currently considering whether a trial and license system regulating the use of nanoparticles in cosmetics should be implemented.
Activist Concerns Get Louder
Friends of the Earth (FOE), an international network of grassroots environmental groups, is one of the most vocal advocates for stricter controls on products containing nanoparticles. The organization is calling for a moratorium on such products and the withdrawal of those already on the market, until adequate safety studies have been completed and regulations put in place.
In a recent report ("Nanomaterials, sunscreens and cosmetics: Small Ingredients, Big Risks"), FOE criticizes government agencies, including the FDA and the Royal Society in the UK, for their lack of action concerning the manufacture and sale of products containing nanoparticles. “The failure of government regulators to take seriously the early warning signs surrounding nanotoxicity suggests that they have learned nothing from any of the long list of disasters that resulted from the failure to respond to early warning signs about previous perceived ‘wonder’ materials (like asbestos, DDT and PCBs).” Other organizations, including the Environmental Defense Fund and the Nanoethics Group, share FOE’s concerns.
For consumers who are faced with advertising for nano-cosmetics that promise reduced wrinkles or whiter teeth, the temptation may prove overwhelming. Whether the promises – or the risks – are real needs to be shown. Nevertheless, until the potential risks are thoroughly studied, should the quest for smoother skin and flashier eye shadow take precedence over health and safety concerns?
Michael Berger By – Michael is author of three books by the Royal Society of Chemistry:
Nano-Society: Pushing the Boundaries of Technology,
Nanotechnology: The Future is Tiny, and
Nanoengineering: The Skills and Tools Making Technology Invisible
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