The Future of SPF

The days of slathering our skin with white pasty creams for sun protection may be numbered. Rather than a barrier between our skin and the damaging rays of ultraviolet radiation, UC San Diego chemists and materials scientists are pursuing an exciting alternative—one that enhances our skin’s natural protective abilities.

Inspiration for the discovery came from an unusual source—the melanin nanoparticles that give the plumage of some birds a colorful and iridescent sheen. While studying melanin in bird feathers, researchers wondered if they could make nanoparticles that mimic melanosomes, the organelle in skin cells that stores and transports melanin and makes our skin less susceptible to ultraviolet (UV) radiation.

“We hypothesized that these nanoparticles would be taken up by keratinocytes, the predominant cells found in the outer layer of skin,” explains Nathan Gianneschi, professor of chemistry, biochemistry, materials science and engineering.

The theory was proven right—in an experiment using human keratinocytes in tissue culture, researchers found the synthetic nanoparticles were not only taken up and distributed like natural melanosomes, they also protected the skin cells from UV damage.

Their achievement is promising not only for an innovative approach to sunscreen, but also for protecting those who lack natural sun protection. “Defects in melanin production cause skin diseases such as vitiligo and albinism, both of which lack effective treatments,” says Gianneschi.

Vitiligo develops when the immune system wrongly attempts to eliminate normal melanin-forming cells from the skin. Albinism results when genetic defects interfere with melanin production. Both skin diseases result in visible loss of pigment on the skin surface, and significantly increase susceptibility to skin cancer.

Yet for all of us at risk under the sun, the development has even wider potential. UC San Diego’s Office of Innovation and Commercialization has filed a patent application on the discovery and fully intends to make the innovations available for the benefit of all.

“There is potential that the nanoparticles could be formulated into a cream, yet that needs to be further studied in detail,” Gianneschi says. “While our study showed that our materials are taken up by human skin cells, the challenge now is to translate that to fully intact tissues, to see if a topical formulation is possible.”

Such a cream, he added, would function as a truly “natural tan,” mimicking and enhancing the process our own skin cells use to protect themselves from the sun.

“If this works, the product would be longer lasting than a standard sunscreen. And it would provide protection from within the skin tissue, rather than a coating on the outside.”