Mussel-inspired anti-permeation hybrid sunscreen with reinforced UV-blocking and safety performance

Sun protection has gradually become an indispensable living habit of human beings, and sunscreens are needed under various circumstances. Considering the disadvantages and abuse of traditional sunscreen additives which are proved to have some potential threats to human body and natural environment, it is an urgent need to develop new sunscreens with both safety and high efficiency for the evolution of the industry. Therefore, as a complement to the shortcomings, polydopamine (PDA) was hybridized with zinc oxide (ZnO) by a simple sol-gel method. The obtained novel sunscreen agent had high ultraviolet (UV) resistance efficiency, as the SPF (similar to 77.2) and PA (PA+++) value at only 10 wt% addition could meet the daily sunscreen requirements. Besides, the permeation of ZnO and Zn2+ could be almost completely avoided through the epidermis layer of skin, due to the increase of mussel-inspired adhesive force. Furthermore, the free radical scavenging rate could reach 88.1% at low concentration, and it was proved to have no cytotoxicity. Overall, the ZnO-PDA has a good application prospect in high-efficiency and safe sunscreen, and it can be an impetus for the development of novel cosmetics.