Asian J Beauty Cosmetol. 2015; 13(5): 615-621.

Development of Novel Detection Method for Evaluation of Keratinocyte Hydration Using Silica gel

Min Hwa Choi, Seunghee Bae, Seungbin Kwon, Yeong Min Choi, Ji Yea Kim, Jun Woo Lee, Min Jung Kim, Kyu Joong Ahn, Sungkwan An, and In-Sook An

Skin hydration is referred as the intra- and intercellular water content in the epidermis and the dermis. There are diverse in vivo assessment methods of the water content of the skin, however, in vitro assessment method of cellular water content has not been largely investigated and developed yet. Here, we developed a novel in vitro simple assessment method of cellular water content in keratinocytes using coloring silica gel. For this, we raised question about three aspects; the first is that whether the level of color change of silica gel can be correlated with the level of water content, the second is that whether the changed level of color can be quantifiable, the third is that whether the cellular water of keratinocytes can be absorbed into silica gel. We simply confirmed that its own ‘Red’ color of silica gel was changed to yellow in a H₂O concentration dependent manner. Next the images of the results were adjusted to be only red and yellow color images, and then the only red color area of the images was extracted by controlling the L*a*b* values of them. Using Image J software, the intensity of the extracted red color area of each image was quantified. And we found that the level of color change is statistically correlated with a H₂O concentration. Then, we investigated whether silica gel could absorb the cellular water of keratinocyte, and the color of silica gel would be changed in a keratinocyte’s water content dependent manner. The intensity level of red color area of silica gel was significantly decreased as the number of keratinocyte increased. Also the level of its red color was different between undifferentiated keratinocyte and differentiated keratinocytes. As a result, these data indicate that the cellular water of keratinocyte can be absorbed into silica gel, and the level of color change of it is statistically correlated with the level of water content of keratinocytes. Therefore, the silica gel-mediated assessment method of water content can be useful for many researches implications and for the evaluation of cosmetics.

Keywords : Skin hydration, Keratinocate, Water content, Silica gel, Color change