Melanin-like Nanoparticles Boosted the Photoprotective Efficiency and Stability of Sanshool

Sanshool, a naturally occurring molecule from Zanthoxylum xanthoxylum, is an essential component preventing photodamage; however, inherent instabilities and the potential risk of skin permeation limit its further application. Inspired by the natural photoprotective mechanism, melanin-like materials were applied to boost the photoprotective efficiency and stability of sanshool. This could be achieved with melanin–sanshool nanoparticles (melanin–S NPs) via facile and efficient boron esterification interactions, yielding melanin–S NPs with uniform sizes and improving stability, effective ultraviolet absorption, and antioxidative capacities in vitro. In addition, the skin permeation, photoprotective activity, and potential mechanism of melanin–S NPs were studied using skin photodamage intracellular and animal models. This bioinspired strategy of melanin-based nanomaterials provides a platform for improving the key properties of naturally occurring functional molecules.