One of the hassles involved with using sunscreen is the fact that you shouldn't just apply it once – depending on who you ask, it should be reapplied at least once every few hours. That isn't the case, however, with an experimental new coating made from DNA. It actually gets more effective the longer it's left on the skin.

Led by assistant professor of biomedical engineering Guy German, a team at New York's Binghamton University developed thin and optically transparent crystalline DNA films, then irradiated them with ultraviolet light. It was found that the more UV exposure the films received, the more their optical density increased, and the better they got at absorbing the rays.

"Ultraviolet light can actually damage DNA, and that's not good for the skin," states German. "We thought, let's flip it. What happens instead if we actually used DNA as a sacrificial layer? So instead of damaging DNA within the skin, we damage a layer on top of the skin."

Additionally, it turns out that the films slow water evaporation through the surface of the skin, thus keeping skin hydrated for longer periods of time. With that in mind, the technology could have at least one other application.

"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," says German.

A paper on the research was recently published in the journal Scientific Reports.