BusinessTN

Cosmos magazine reported earlier this year about two new Australian studies finding that zinc from sunscreens have been found to penetrate healthy adult skin. “The results raise questions over the safety of sunscreens containing zinc oxide nanoparticles,” the magazine reported, “which may be dangerous in the body if still in a nanoparticle form.”

Other recent studies have shown that the small-scale metal oxides in sunscreen can wind up in organs such as the liver or brain. But a University of Tennessee professor has found a better alternative than the toxicity involved the use of metal-based nanoparticles in sunscreen. In a word, ivy.

Mingjun Zhang, an associate professor of biomedical engineering at UT-K, along with his research team and collaborators, found that ivy nanoparticles may protect skin from UV radiation at least four times better than the metal-based sunblocks founds on store shelves today.

How did he discover that? It all started with Zhang pondering a simple question: “What made the ivy in his backyard cling to the fence so tightly? The answers he found led to a pioneering discovery that the tiny particles secreted from ivy rootlets can be used in many breakthrough applications in items, including sunblock.

According to the university, Zhang speculated that the greenery’s hidden power lay within a yellowish material secreted by the ivy for surface climbing. He placed this material onto a silicon wafer and examined it under an atomic force microscope and was surprised by what he found — lots of nanoparticles, tiny particles 1,000 times thinner than the diameter of a human hair. The properties of these tiny bits create the ability for the vine leaves to hold almost two million more times than its weight. It also has the ability to soak up and disperse light, which is integral to sunscreens.

“Nanoparticles exhibit unique physical and chemical properties due to large surface-to-volume ratio which allows them to absorb and scatter light,” Zhang said. “Titanium dioxide and zinc oxide are currently used for sunscreen for the same reason, but the ivy nanoparticles are more uniform than the metal-based nanoparticles, and have unique material properties, which may help to enhance the absorption and scattering of light, and serve better as a sunblocker.”

Ivy nanoparticles, on the other hand, exhibit better biocompatibility with humans and the environment. The team’s studies indicate that the ivy nanoparticles were less toxic to mammalian cells, have a limited potential to penetrate through human skin and are easily biodegradable.

“In general, it is not a good idea to have more metal-based nanoparticles for cosmetic applications. They are a significant concern for the environment. Naturally occurring nanoparticles originated from plants seem to be a better choice, especially since they have been demonstrated to be less toxic and easily biodegradable,” Zhang said.

Sunscreens made with ivy nanoparticles may also not need to be reapplied after swimming. That’s because the plant’s nanoparticles are a bit more adhesive so sunscreens made with them may not wash off as easily as traditional sunscreens. And while sunscreens made with metal-based nanoparticles give the skin a white tinge, sunscreens made with ivy nanoparticles are virtually invisible when applied to the skin.

Bring on the sun.