Researchers at Yale University say they have developed the ultimate long lasting, safe sunscreen. However, they do admit animals were used to test it.
Mark Saltzman, a biomedical engineer at the University says, “The initial goal was to make a sunblock that lasted longer. But as I read more about sunscreen, I became aware of people’s concerns about safety.” Now Saltzman and Yale research colleagues say they have found the solution – a nanoparticle-based sunblock, which they claim is longer lasting than anything on the market and less likely to be absorbed into the body like traditional sunscreens.
Saltzman explained that sunscreens currently on the market work in one of two ways: by providing a chemical skin coating which filters out harmful UV rays before they reach the skin, or by blocking out sunlight with a zinc oxide paste. He says studies have shown the chemicals in these sunscreens have been found in human breast milk and urine, meaning they penetrate the skin’s outer layers and leach into the body. Other studies show the chemicals protecting us from UV damage can produce DNA-damaging molecules.
In the new Yale sunscreen, the researchers used minute nanoparticles that tightly stick to protein-rich surfaces, like the skin, and engineered them to form a chemical UV filter. They found that not only did these nanoparticles not penetrate the skin, but they were also more efficient than sunscreens now being used, needing only five percent of the UV protection chemicals.
Saltzman admits mice were used to test their product. They shaved the fur off four mice, sprayed them with the clear nanoparticle solution and exposed them to UV light. Comparing these mice to another four covered in traditional sunscreen, they found that although both groups were protected from key signs of UV damage, the mice with the new sunscreen had no traces of chemicals in their bodies, whereas the traditional sunscreen ones did.
Yale dermatologist Michael Girardi says the nanoparticle sunblock is water resistant but can be wiped off, and on the trial mice it was effective for five days.
Saltzman says they are not yet allowed to try out the product on humans, but they are in the process of applying for permission.
“I’ll certainly be the first volunteer if it’s allowed.” he said.