https://www.scientificamerican.com/article/dna-sunscreen-gets-better-not-weaker-over-time/

Many sunscreens wear off over the course of a day, but a DNA material developed by US scientists gets better at absorbing ultraviolet (UV) light the longer it is exposed to it.1The transparent coating could protect skin – particularly damaged areas – from sunburn over long periods of time.

‘UV light is particularly bad for wounds because the skin is already weakened,’ explains Clara Piccirillo a materials chemist from the Portuguese Catholic University, who previously developed a fishbone-derived sunscreen but wasn’t involved in this study. ‘There is a lot of research to try and find multifunctional materials for dressings, for instance something antibacterial that at the same time protects from UV light.’