Scientist Creates Sunscreen from Ivy

Aug 03, 2010 By Devin Powell
Credit: Harry Quarles, Mike Ryon

Drive through the University of Tennessee in Knoxville on a sunny day, and you may see a man on the side of the road pruning the English ivy.

Mingjun Zhang isn't the groundskeeper. He is a biomedical engineer at UT who harvests the vine to make a new kind of sunscreen. He hopes to replace the metal particles in commercial sunscreens with an organic, non-toxic alternative.

" is an incredibly useful plant," said Zhang, who was born in China, where the plant is an ingredient in traditional medicine.

Zhang's interest in ivy began a few years ago in his backyard, where he asked a simple question: how does it stick so tightly to the fence?

The secret ivy's clinging power, Zhang discovered, is in its secretions, which contain nanoparticles a thousand times smaller than a grain of sand. The unusual shape of these particles allows them to form strong bonds with the surfaces of fences and walls.

While studying the unique shape of these particles, Zhang found that they also absorb the ultraviolet rays in sunlight.

Commercial sunscreens already contain that block UV rays and protect against sunburn and skin cancer. These metal compounds, such as and , give many creams their white color.

Recent studies have questioned the safety of metal nanoparticles. When inhaled or consumed -- by workers in manufacturing plants -- they may increase cancer risks, according to a study at the University of California, Los Angeles, which showed that it can damage the DNA of mice.

Emerging safety studies have yet to find any clear evidence of danger from metal nanoparticles in sunscreen lotions, though. Preliminary research conducted by researchers at the U.S. who rubbed pigs with sunscreen for weeks suggested that the nanoparticles did not penetrate skin deep enough to cause harm. Further toxicity studies are still underway.

While claims of risk are still uncertain, one thing is clear: sunscreens that contain these compounds cut the risk of skin cancer, and even the scientists studying potential health effects recommend them.

"New tools are allowing us to check the human and environmental impacts of technologies developed decades ago," said Bob Peoples, director of the American Chemical Society's Green Chemistry Institute in Washington, D.C. "Our goal now is to reduce or eliminate the generation or use of hazardous substances."

As more testing is performed on the nanosized metal compounds, used in everything from paint to vitamins, many researchers are searching for organic alternatives.

Zhang's ivy nanoparticles, one alternative, have proven to be transparent, water resistant, and non-toxic to living cells. They block UV radiation four times more effectively than do metal nanoparticles and are broken down naturally over time by enzymes on the skin. He is currently seeking a patent for the discovery, published in the Journal of Nanobiotechnology.

It may be a while before ivy-based sunscreens appear on the shelf of your local drugstore, said Joe Laszlo, a scientist at the Agriculture Research Service in Peoria, Ill. "The science is the easy part," said Laszlo. "The hard part is the economics, the millions of dollars it takes to get FDA approval."

Several years ago, Laszlo developed a UV-blocking compound based on soybean oil that never made it into sunscreens. Today, the soy compound is used in cosmetics instead, which don't require FDA approval for their claims of protection from the sun and "reduction of fine lines and wrinkles."

Zhang is talking to companies interested in making sunscreen and cosmetics, and he is also exploring other applications including surgical super-glue for sealing wounds and using the nanoparticles to carry drug molecules inside the human body.

Explore further: Demystifying nanocrystal solar cells

Source: Inside Science News Service

5 /5 (8 votes)

Related Stories

To sun, or not to sun?

Apr 17, 2009

You ditched the baby oil with iodine ions ago, but you still have some burning questions about less-obvious sun no-no's. Now that spring is here and everyone's exposure time is likely to increase, get updated on the latest ...

Recommended for you

Demystifying nanocrystal solar cells

11 hours ago

ETH researchers have developed a comprehensive model to explain how electrons flow inside new types of solar cells made of tiny crystals. The model allows for a better understanding of such cells and may ...

Researchers use oxides to flip graphene conductivity

Jan 26, 2015

Graphene, a one-atom thick lattice of carbon atoms, is often touted as a revolutionary material that will take the place of silicon at the heart of electronics. The unmatched speed at which it can move electrons, ...

Researchers make magnetic graphene

Jan 26, 2015

Graphene, a one-atom thick sheet of carbon atoms arranged in a hexagonal lattice, has many desirable properties. Magnetism alas is not one of them. Magnetism can be induced in graphene by doping it with magnetic ...

The latest fashion: Graphene edges can be tailor-made

Jan 23, 2015

Theoretical physicists at Rice University are living on the edge as they study the astounding properties of graphene. In a new study, they figure out how researchers can fracture graphene nanoribbons to get ...

Nanotechnology changes behavior of materials

Jan 23, 2015

One of the reasons solar cells are not used more widely is cost—the materials used to make them most efficient are expensive. Engineers are exploring ways to print solar cells from inks, but the devices ...

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.