Nanotechnology and the Science of Beauty
Celebrities like Jennifer Aniston and Demi Moore just never seem to age. Those of us without access to teams of make-up artists and airbrushing may wonder whether we, too, can make fine lines and wrinkles a thing of the past. When strolling past the cosmetics counter at Macy’s, hundreds of skincare products promising eternal youth and beauty compete for our attention. From creams containing stem cells to those claiming to repair damaged DNA, companies are using science to entice customers. Manufacturers are even investing in and promoting nanotechnology. Such advertising can be confusing and lead patrons to believe that these products yield unparalleled results. Is this a gimmick or can nanotechnology actually revolutionize the cosmetics industry?
Nanotechnology is the study of nanoparticles, and by definition, a nanoparticle is any material measuring less than 100 nanometers in at least one dimension. To put that into perspective, a nanoparticle is at least 10,000 times smaller than the period in this sentence. Many nano-sized materials have unique optical, thermal, electrical, and/or magnetic properties and have been included in everyday items, such as cosmetics and paints, for several years.
For example, sunscreens regularly contain titanium dioxide and zinc oxide nanoparticles due to their ability to absorb ultraviolet (UV) radiation. Silver nanoparticles, which have antibacterial activity, are also being incorporated into toothpastes and shampoos as preservatives. Cosmetics giant L'Oréal invested $927 million in cosmetic and dermatological research in 2011 and is an industry leader in nanotechnology-related patents.
But, newly developed cosmetics create exceptionally high expectations for nanotechnology. Oro Gold Cosmetics, whose products cost as much as $1,398 for a face mask, includes gold nanoparticles in its formulas and claims that these nanoparticles have anti-inflammatory and antioxidant properties, drive tissue regeneration, restore skin elasticity, and reduce signs of stress and aging. However, there isn’t concrete proof that these tiny particles pack such a massive punch.
Although the use of nanoparticles in some topical ointments is rather common, the effects of nanoparticles on the skin are not completely understood, and researchers are gradually working to identify how the two entities interact. Many studies have revealed that the nanoparticles used in sunscreens, which function to protect the outer layers of the skin (the epidermis), permeate through the skin minimally or not at all. Unlike sunscreens, nanoparticles in anti-wrinkle regiments would need to reach the middle layers of the skin (the dermis) in order to target the cellular proteins responsible for aging. These proteins, known as collagen and elastin, are responsible for maintaining the structure and flexibility of skin. Skin cells regenerate less frequently with age, and collagen and elastin become less effective.
But, one study recently published in the Proceedings of the National Academy (PNAS) suggests that nanoparticle permeation through skin is actually possible. Drs. Chad Mirkin and Amy Paller of Northwestern University found that keratinocytes, the most common type of skin cell, take up gold nanoparticles specially designed to inactivate a gene implicated in cancer development and progression. After applying these nanoparticles to mouse and human skin models, the vast majority of the nanoparticles penetrate through several layers of skin within a matter of a few hours. Drs. Mirkin and Paller demonstrate that these nanoparticles successfully suppress the cancer-related gene, the most notable accomplishment of its kind thus far. Previously, gene regulation in skin has proven challenging because the skin is an exceptionally strong barrier that resists entry of chemical agents, yet gold nanoparticle-mediated drug delivery shows great promise in overcoming this obstacle. These findings could pave the way for a new line of treatments for conditions such as melanoma, one of the deadliest forms of skin cancer.
Should nanoparticles traverse the skin barrier, nanotechnology could also transform traditional cosmetics and cosmetic procedures, according to Dr. Adnan Nasir, dermatologist from the University of North Carolina at Chapel Hill. For example, retinoids, which are derivatives of Vitamin A shown to improve the appearance of skin, are sensitive to and made less efficient by sunlight. In an article in the medical journal Skin Therapy Letter, Dr. Adnan proposes that nanotechnology may increase the stability of retinoids and allow the compounds to better reach the lower layers of the skin. Additionally, Dr. Adnan speculates that nanoparticles may one day deliver materials that currently require injection such as botulism toxin, more commonly known as BOTOX, without needles.
But, it is critical to test the safety of nanoparticles throughout their various applications because nanoparticles have the potential to be more reactive than their larger counterparts. One of the largest fears is that nanoparticles could penetrate below the skin and accumulate in other tissues or organs and induce toxicity. There is also concern that nanoparticles could contaminate water and thereby harm the environment. Evidence of these phenomena is still under investigation, and the Federal Drug Administration (FDA) recently outlined guidelines for the use of nanotechnology by the cosmetics industry.
The prospect of turning back the clock with something as simple as a lotion is enticing. But we have only just begun to really understand the relationship between science and beauty. More extensive research and safety testing in the future should better separate the risks from the rewards of incorporating nanotechnology into cosmetics. But until the anti-aging nanoparticle products currently on the market are further developed and evaluated, do your wallet a favor on your next trip to Macy’s and opt for less flashy alternatives.
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