Posted: July 24, 2007

Nanotechnology skin deep

(Nanowerk News) One way nanotechnology is being incorporating into skin care is by using it to break down an active ingredient into nanoparticles. Another way is when "nanometer-sized liposomes [-- essentially nanometer-sized capsules -- are used in an attempt to allow vitamins and other materials to be absorbed more effectively by the skin," says Dr. Andrew Maynard, chief science adviser for the Project on Emerging Nanotechnologies at the Woodrow Wilson International Center for Scholars in Washington, D.C. This generally involves placing a tiny droplet or particle of an ingredient into another droplet, which serves as a vehicle. Basically, the vehicle droplet is small enough to deeply penetrate the skin, taking the main ingredient along for the ride.
Why go deeper?
When you apply a product to your skin, it has a long way to go to do its job. Our outer layer of skin -- the epidermis -- has 30 layers of dead skin cells, then five more sub layers of living cells before you reach the dermis -- the middle layer of skin where many active ingredients act. "The deeper materials can travel the more skin layers they encounter, and the more available they can be to more skin in less time," Yechiel says. According to some nanotech companies, getting products deeper will also allow them to work better.
Not much public proof
While there are some published studies that suggest that solid lipid nanoparticles penetrate the skin better than conventional creams, overall it's difficult to find studies showing nano-engineered products are more effective than regular ones or that they are effective at all. The highly competitive world of cosmetics may have something to do with the lack of published studies. Because publishing the results of scientific tests requires full disclosure of the method by which the formulation being tested was produced, companies wishing to protect proprietary nanotechnology are understandably not anxious to do so. Bottom line: Nano-engineered cosmetics may work well, but we don't have easily available proof that they do because large-scale studies of them haven't yet been made public.
Safety issues
Some experts have voiced concerns about the safety of nanotechnology. For instance, some sunscreens use nanoparticles of titanium dioxide or zinc oxide, and there are experts who have raised the question of whether these substances remaining in the skin can age it prematurely. According to the U.S. Food and Drug Administration, "At the present time, the FDA does not have any evidence that ingredients manufactured using nanotechnology, as used in cosmetics, pose a safety risk." However, the FDA and other government agencies are still studying nanotechnology to see if the products produced with it -- including cosmetics -- pose health risks. So as of yet, there seem to be no definitive answers.
Source: ScrippsNews (Paige Herman and Marie Kuechel)
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