In the summer months, when the days are longer and the sun is stronger, many of us dive deep into the outdoors. We often apply sunscreen before sun exposure, but forget to reapply well after, leaving our skin vulnerable to sun damage. Now, researchers at Binghamton University have developed a DNA film that better protects human skin the more it’s exposed to ultraviolet (UV) light.

The DNA film is used as a sacrificial layer so UV rays damage a layer on top of the skin rather than DNA within the skin. Thin and optically transparent crystalline DNA films were developed and then irradiated with UV light. Here, the researchers found the DNA film was better at absorbing the light when it was exposed to it for a longer duration.

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"If you translate that, it means to me that if you use this as a topical cream or sunscreen, the longer that you stay out on the beach, the better it gets at being a sunscreen," said Guy German, study author and assistant professor of biomedical engineering at Binghamton University, in a statement.

Sunscreen works by preventing the sun's UV radiation — UVA and UVB — from penetrating the skin; it offers protection from UVA rays if it includes the words "broad spectrum". Both types damage the skin, age it prematurely, and increase the risk of skin cancer. UVB is responsible for sunburn, while UVA rays, which penetrate the skin more deeply, are linked to wrinkling, leathering, sagging, and other light-induced effects of aging, according to the Skin Cancer Foundation.

Sunscreens should be applied 30 minutes before sun exposure so the ingredients can bind to the skin, and reapplied every two hours. However, sunscreen should be reapplied immediately after swimming, toweling off, or sweating profusely. Application and reapplication is vital since UV rays from the sun and other sources, like tanning beds, are the number one cause of skin cancer.

With the development of the DNA film, beach goers can use it once, without worrying about reapplying. Moreover, the coatings are hygroscopic, which means the skin coated with the DNA films can store and hold water much more than uncoated skin. Therefore, when it's applied to human skin, the films can slow water evaporation and keep the tissue hydrated for a longer duration.

Skin exposed to UV rays without protection can lead to dryness and skin pigmentation. The buildup of dead and dry skin on the outermost layer of the skin can make it appear dry, flaky, and uneven. However, with the DNA film, sunbathers can protect their skin and keep it hydrated, even after sun exposure for extended periods of time.

German and the research team are optimistic about the potential use of their DNA film.

"Not only do we think this might have applications for sunscreen and moisturizers directly, but if it's optically transparent and prevents tissue damage from the sun and it's good at keeping the skin hydrated, we think this might be potentially exploitable as a wound covering for extreme environments," he said.

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Further research is needed to test the film's efficacy on human skin in a series of clinical trials.

Meanwhile, previous research has observed how we can further protect ourselves from the sun with certain foods. A 2010 study, published in the Journal of British Dermatology, found 20 healthy women who ate a quarter cup of tomato paste in olive oil every day for three months received more protection against sunburn than those who consumed olive oil alone. Researchers believe the antioxidant lycopene, found in tomatoes, is effective in preventing UV radiation and skin cancer.

The development of a DNA film and eating skin-friendly foods can help lessen the incidence of skin cancer per year. In 2017, it’s estimated a total of 87,100 new cases of invasive melanoma will be diagnosed, while an estimated 9,730 people will die of melanoma in the U.S. Melanoma accounts for less than one percent of skin cancer cases, but the vast majority of skin cancer deaths, with most melanomas caused by the sun.

Although many risk factors for melanoma have been identified, it’s not always clear what causes melanoma skin cancer. UV rays are a major cause of melanoma as they damage the DNA in skin cells. This damage may affect certain genes that control how skin cells grow and divide, but if these genes do not function properly, the affected cells can become cancerous, according to the American Cancer Society.

The use of a DNA film as a sunscreen can help enforce safe sun practices, even for the most outdoorsy.

Source: German G et al. Non-ionising UV light increases the optical density of hygroscopic self assembled DNA crystal films. Scientific Reports. 2017.

See Also:

Drinking Alcohol In The Sun May Increase Skin Cancer Risk

7 Common Sunscreen Myths That May Be Aging Your Skin