Suppression of Sunscreen Leakage in Water by Amyloid-like Protein Aggregates

A sunscreen offers indispensable skin protection against UV damage and related skin diseases. However, due to the poor interfacial stability of sunscreen coatings on the skin, the synthetic ingredients in sunscreen creams easily fall off and enter aquatic environments, causing large ecological hazards and skin protection failure. Herein, we tackle this issue by introducing amyloid-like protein aggregates into a sunscreen to noticeably enhance the interfacial robustness of sunscreen coatings on the skin. The synthesis of such an agent to suppress sunscreen leakage can be achieved by manipulating the phase transition of bovine serum albumin (BSA) in a mild aqueous solution at room temperature. The resulting phase-transitioned BSA (PTB) aggregates effectively entrap the sunscreen ingredients to generate a uniform cream coating on the skin with robust amyloid-mediated interfacial adhesion stability. With continuous flushing in aquatic environments, such as salt water and seawater, this PTB-modified sunscreen (PTB sunscreen) coated on the skin maintains a retention ratio as high as >92%, which is 2-10 times higher than those of commercially available sunscreen products. The high retention ratio of the PTB sunscreen in aquatic environments demonstrates the great potential of amyloid-like protein aggregates in the development of leakage-free sunscreens with low ecosystem hazards and long-lasting UV protection in aquatic environments.

Automated summary

By incorporating amyloid-like protein aggregates into sunscreen, the study successfully improves the interfacial stability of the sunscreen on the skin, preventing leakage and entry of synthetic ingredients into aquatic environments. The modified sunscreen shows high retention ratio in aquatic environments, indicating the potential for developing leakage-free sunscreens with low ecological hazards and long-lasting UV protection.