The rapidly growing field of nanotechnology and its future use in
cosmetic products holds both enormous potential and potential
concern for consumers. Currently, major cosmetic manufacturers have
imposed a voluntary ban on the use of nanoparticles in products
while they await a ruling from the Food and Drug Administration
(FDA) regarding the safety of this technology.
However, these manufacturers know that when ingredients in
products such as sunscreens and anti-aging products are converted
into nano-sized particles, the end product displays unique
properties that can benefit the skin in ways that otherwise could
not be achieved using larger-sized particles.
Speaking today at the 68th Annual Meeting of the American
Academy of Dermatology (Academy), dermatologist Adnan Nasir,
MD, PhD, FAAD, clinical assistant professor in the department of
dermatology at the University of North Carolina in Chapel Hill,
presented an overview of nanotechnology and how nanoparticles may
eventually be used in cosmetic products.
"Research in the area of nanotechnology has increased
significantly over the years, and I think there will be
considerable growth in this area in the near future," said Dr.
Nasir. "The challenge is that a standard has not been set yet to
evaluate the safety and efficacy of topical products that contain
nanosized particles."
Nanotechnology: On the Plus Side
Products incorporating nanotechnology are being developed and
manufactured at an ever-growing rate, especially among clothing
manufacturers that incorporate nanomaterials into fabrics to
enhance stain and wrinkle resistance, and water repellence.
However, Dr. Nasir explained that a substantial proportion of
patents issued for nanotechnology-based discoveries are currently
in the realm of cosmetic and consumer skin care products. In fact,
the cosmetic industry leads all other industries in the number of
patents for nanoparticles, which have the potential to enhance
sunscreens, shampoos and conditioners, lipsticks, eye shadows,
moisturizers, deodorants, after-shave products and perfumes.
One example of how nanoparticles are being considered for use is
to improve some of the undesirable properties of skin care
products. Dr. Nasir explained that when certain ingredients are
included in micrometer-sized particles, which are considerably
larger than nanosized particles, the result is a product than can
be cosmetically unappealing.
For example, one common ingredient in broad-spectrum sunscreens,
which protect the skin from both UVA and UVB rays, is avobenzone,
which can make a sunscreen greasy and very noticeable when applied
to the skin. Since titanium, another common sunscreen ingredient,
requires an oily mixture to dissolve, a white residue can be
apparent on the skin upon application. However, when these active
ingredients in sunscreens are converted into nanoparticles, they
can be suspended in less greasy formulations - which seem to vanish
on the skin and do not leave a residue - while retaining their
ability to block UVA and UVB light.
"While widespread use of this technology is currently under
evaluation, I think one of the main benefits of nanoparticles used
in sunscreens will be that the particles can fit into all the nooks
and crannies of the skin, packing more protection and more even
coverage on the skin's surface than microsized particles," said Dr.
Nasir. "Since sunscreen formulations using nanoparticles may be
more cosmetically appealing and seem to vanish when applied,
consumers may be more inclined to use them on a regular basis."
Nanotechnology also is generating excitement for its potential
use in anti-aging products. When properly engineered, nanomaterials
may be able to topically deliver retinoids, antioxidants and drugs
such as botulinum toxin or growth factors for rejuvenation of the
skin in the future.
In anti-aging products, Dr. Nasir added that nanotechnology may
allow active ingredients that would not normally penetrate the skin
to be delivered to it. For example, vitamin C is an antioxidant
that helps fight age-related skin damage which works best below the
top layer of skin. In bulk form, vitamin C is not very stable and
is difficult to penetrate the skin. However, in future
formulations, nanotechnology may increase the stability of vitamin
C and enhance its ability to penetrate the skin.
"Since anti-aging products that contain nanoparticles of
antioxidants will be harder to make, we expect that these products
will cost more than products using traditional formulations," said
Dr. Nasir. "Once these products are determined to be safe, the
consumer will have to decide if the increased costs are worth the
added benefits."
Nanotechnology: Future Melanoma Treatment
Researchers also are reviewing the use of nanomaterials for the
treatment of melanoma. In particular, gold, when turned into a
nanomaterial called nanoshells, has been shown to be a useful
treatment for melanoma in animal studies.
According to Dr. Nasir, gold nanoshells can be engineered to
absorb specific wavelengths of light. If the wavelength of light
unique to a particular type of gold nanoshell is used on it, the
particle generates heat. In one animal study done at MD Anderson
Cancer Center in Houston, investigators joined gold nanoshells with
a molecule which homes to melanoma. When these gold nanoshells are
injected into mice harboring melanoma, the nanoshells accumulate in
the cancerous tissue. When mice are illuminated with the proper
wavelength of light, their tumors, laden with gold nanoshells, heat
up and are effectively killed. The surrounding tissue, which lacks
targeted gold nanoshells, is unharmed.
"Nanotechnology holds promise for new non-invasive treatment
methods, particularly for challenging dermatologic conditions, such
as atopic dermatitis and ichthyosis," said Dr. Nasir.
Nanotechnology: More Consumer Information Needed
Because the skin is the first point of contact and the first line
of defense for newly manufactured nanomaterials, Dr. Nasir noted
that many dermatologists have concerns about the potential health
risks posed by nanotechnology. "Although nanotechnology is an
exciting area that holds enormous potential," said Dr. Nasir, "we
anxiously await the FDA's review of the safety of nanoparticles
which will determine their future role in skin cancer
products."
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