Researchers at UCLA have unveiled a groundbreaking mineral sunscreen that significantly reduces the white, chalky cast often associated with traditional zinc oxide formulas. This innovation, led by the UCLA Health Jonsson Comprehensive Cancer Center, promises to make sunscreen more appealing and accessible, particularly for individuals with darker skin tones.
The study, published in ACS Materials Letters, highlights how altering the shape of zinc oxide particles can address one of the most common cosmetic drawbacks of mineral sunscreens. By engineering zinc oxide into tetrapod-shaped particles, the researchers have created a formulation that provides robust ultraviolet protection while appearing warmer and more natural on the skin.
Addressing a Long-standing Cosmetic Concern
Mineral sunscreens, known for their ability to block both UVA and UVB rays, are often recommended for individuals with sensitive skin. However, their tendency to leave a white residue has discouraged many from using them regularly. This is particularly true for people with darker skin tones, who find the white cast more pronounced and unappealing.
Paul S. Weiss, the senior author of the study and a distinguished professor at UCLA, emphasized the broader implications of this development. “If improving how sunscreen looks leads to more consistent use, it could have real implications for skin cancer prevention,” he noted.
The Science Behind the Innovation
The breakthrough came from a simple yet effective change in the zinc oxide particle structure. Traditional zinc oxide particles are small and round, often clumping together and scattering visible light, which results in a white cast. The UCLA team, however, utilized a patented high-temperature flame process to create larger, tetrapod-shaped particles.
According to AJ Addae, a UCLA chemical biology doctoral candidate and the study’s first author, “Because of their structure, these tetrapod-shaped particles have standoffs and form porous networks instead of collapsing into clumps.” This unique structure prevents the particles from packing tightly, ensuring they remain evenly distributed in the sunscreen.
“When formulated into test sunscreens at the same concentration as conventional zinc oxide, the tetrapod-based sunscreen achieved a sun protection factor (SPF) of about 30, which is comparable to standard mineral sunscreens.”
Implications for Skin Cancer Prevention
The potential impact of this innovation extends beyond cosmetics. Consistent sunscreen use is crucial for preventing skin cancer, the most common cancer in the United States. Despite this, many Americans skip sunscreen due to its aesthetic drawbacks. By making sunscreen more visually appealing, UCLA’s research could encourage more widespread and regular use.
This is particularly important for people with darker skin tones, who are often diagnosed with skin cancer at later stages. While melanoma is less common in these populations, it is more deadly due to late detection. Addae’s personal experience with the white cast of mineral sunscreens fueled his motivation for the project. “A lot of my motivation came from my own experience trying to use mineral sunscreen and dealing with the white cast,” he explained.
Next Steps and Future Research
While the initial results are promising, further testing is necessary before this technology becomes commercially available. The UCLA team is collaborating with the UCLA Health department of dermatology and the Skin of Color Clinic to study how these tetrapod particles interact with the skin microbiome.
The study, which also involved researchers Jennifer Uyanga and professor Justin Carman of UCLA chemistry, as well as professor Yogendra Kumar Mishra of the University of Southern Denmark, was funded by the National Science Foundation, the Challenge Initiative at UCLA, and a Sigma Xi IFoRE Grant-in-Aid.
As Addae succinctly put it, “The best sunscreen is the one people will actually use.” If this new formulation can maintain its protective qualities while being more aesthetically pleasing, it could mark a significant step forward in public health and skin cancer prevention.
