Photoprotection: new concepts, controversies and trends in 2022

Abstract

Photoprotection appeared, on technical if not scientific bases, in the 1930’s.It was created for permitting tanning without burn. This concept lasted until the 1980’s and then evaoluted, due to both scientific advances permitting to reach higher SPF’s, but also more and more concern of the population about the nocious effects of sun exposure on the occurrence of skin cancers. At that time, it was demonstrated that sun radiation was not only able to favour the development of carcinomas and melanomas, but also to speed up the visible signs of skin aging. This made that nowadays, photoprotection turns to be a responsible act and a daily routine. This paper intends to update the current knowledge about photoprotection. We lastly discovered that not only UVA/UVB but also visible light and infrared radiation, i. e. the complete sun spectrum, is negatively impacting the skin, hence the necessity of creating a full spectrum photoprotection. Dark cyclobutane pyrimidine dimers formation following sun exposure is becoming an urgent concern, and photolyases are probably a solution to reduce the formation of these compounds and repair the damages they are susceptible to cause in the skin. Other concerns are also the levels of vitamin D in the organism, which could be impacted by the regular use of high SPF photoprotection, the frequent use of mineral nanoparticles as sunscreens, the possible impact of certain sunscreens on the human health and also the potential environmental damage they may cause. Finally, an evolution of sunscreens toward more elegant, pleasant and easy to use formulations is certainly the guarantee of a better compliance of the patients with photoprotection.