Size-dependent 2D nanoclay against ultraviolet B-induced damage in vitro and in vivo

Ultraviolet B (UVB) radiation from sunlight has been epidemiologically identified as the main risk factor for skin photodamage such as skin pigmentation and cancer. Kaolinite two-dimensional (2D) nanoclay with suitable size has been used to prevent acute and chronic effects of UVB through specular reflection. However, the large size of 2D nanoclay absorbs sunlight as heat, and the small size of 2D nanoclay blocks sunlight incompletely. The UVB-induced zebrafish embryo pigmentation and the guinea pig skin erythema reaction and skin-stimulating response of kaolinite 2D nanoclay are size-dependent. Guinea pig skin treated with Kaolinite(0.5 mu m) (0.5 mu m of kaolinite) showed the slightest skin irritation, and the protective effect against UVB was similar to that of the commercial sunburn Winona. Research on the size-dependent blocking effect of kaolinite 2D nanoclay against UVB-induced skin photodamage provides a complete analysis of the different sizes of 2D nanoclay to achieve UVB blocking.