Researchers at the University of California, Los Angeles (UCLA) developed a mineral sunscreen that significantly reduces white cast with the hopes of making daily sun protection more accessible.
The study, led by researchers at the UCLA Health Jonsson Comprehensive Cancer Center, investigated a change in the shape of zinc oxide particles to reduce white cast. The new shape (called tetrapods) provides strong protection against UV radiation without the signature chalky cast. The findings were published in Material Letters, a publication of the American Chemical Society.
“This isn’t just about cosmetics,” said senior author Paul S. Weiss in UCLA’s press release. “If improving how sunscreen looks leads to more consistent use, it could have real implications for sin cancer prevention.”
Most sunscreen formulations with zinc oxide are made with small, roughly round nanoparticles. Using a patented high-temperature flame process, the researchers produced larger particles shaped like tetrapods. When compared with conventional zinc oxide nanoparticles, the team found that sunscreens formulated with the tetrapod-shaped particles offered several benefits, including improved stability, fewer signs of separation or thickening, and a significantly reduced white cast.
“Because of their structure, these tetrapod-shaped particles have standoffs and form porous networks instead of collapsing into clumps, said chemical biology doctoral candidate AJ Addae. “They can’t pack tightly and aggregate, so they stay evenly distributed in the sunscreen.”
The researchers plant to continue investigating this formulation in association with UCLA Health’s Skin of Color Clinic to study how the particles interact with the skin microbiome.
