Nanoparticles: A closer look at their dermal effects

Nano-sized particles represent a unique class of materials with novel physiochemical properties due to increased surface area. Many sunscreens and cosmetics are now using nano-sized titanium dioxide and zinc oxide, which avoids the white, chalky appearance of the older preparations. Although the U.S. Food and Drug Administration (FDA) has determined that nano-sized titanium dioxide is not a new ingredient, but a specific grade of the original product, recent studies suggest that nanomaterials products may not be equivalent to their respective bulk-form products, and the adverse effects of nanoparticles cannot be reliably predicted from the properties of the material in bulk form. Nanoparticles are incorporated into a variety of skin care products, and in the future may be useful as transdermal drug delivery devices. Thus, understanding potential epidermal and dermal penetration, as well as possible toxicity, is important to the field of dermatology. The authors present a review of the therapeutic applications and potential toxicity of nanoparticles relevant to the field of dermatology thus far.