Abstract
BACKGROUND: Skincare using facial humidifiers is gaining attention and has become more popular in Japan as a beauty treatment. A novel type of face humidifier capable of generating ultrafine water droplets has been developed recently. MATERIALS AND METHODS: The change in distribution of sprayed ultrafine water droplets in the stratum corneum of excised human skin over the application period was investigated using confocal Raman microscopy. In addition, changes in trans-epidermal water loss (TEWL) value were evaluated after treatment with ultrafine water droplets using a three-dimensional cultured human skin model (3D skin model). Furthermore, the effect of gene expression related to ceramide production in the skin and ceramide production were also evaluated using a 3D skin model by real-time PCR and high-performance thin-layer chromatography, respectively. RESULTS: A higher water content at the surface of the skin was confirmed over 45 min after the application. Furthermore, the TEWL value after the application of ultrafine water droplets was sharply decreased. Increased gene expression related to ceramide production was confirmed compared with the application of purified water, and increased levels of ceramide NS were observed. CONCLUSION: These results suggested that the application of ultrafine water droplets on the skin surface may be useful to maintain a physiologically good skin barrier condition.