背景:角质层(SC),皮肤表皮的最外层,作为一个有效的双向屏障,防止水分流失(内外屏障)和异物进入(内外屏障)。尽管经皮水分流失(TEWL)是一种广泛使用的屏障功能指标,它只代表内外保护。因此,我们旨在建立一种非侵入性的方法来定量评估内外屏障功能,并直观地呈现皮肤屏障模型。
方法:通过在八名参与者的前臂上应用1%十二烷基硫酸钠的封闭贴片来诱导皮肤屏障损伤;指示他们每天两次在指定的受损区域上应用屏障霜,持续5天。通过测量TEWL和荧光素钠盐的渗透率来评估SC屏障,紧接着,损坏后5天。使用胶带剥离(TS)技术和荧光显微镜评估渗透率。
结果:基于皮肤屏障损伤的程度,荧光素钠盐渗透到SC下层的速率显着不同。在两轮TS之后,渗透率与TEWL之间的相关性较弱,并且在随后的轮次之后变得更强。皮肤屏障损伤后五天,在使用和不使用屏障霜的区域之间,所有层的渗透率都存在显着差异。
结论:我们的研究结果表明,渗透速率取决于皮肤屏障条件。穿透率和相应的荧光图像是合适的定量指标,其可以在视觉上表示皮肤屏障状况。
BACKGROUND: The stratum corneum (SC), the outermost layer of the skin epidermis, acts as an effective bi-directional barrier, preventing water loss (inside-outside barrier) and entry of foreign substances (outside-inside barrier). Although transepidermal water loss (TEWL) is a widely-used measure of barrier function, it represents only inside-outside protection. Therefore, we aimed to establish a non-invasive method for quantitative evaluation of the outside-inside barrier function and visually present a skin barrier model.
METHODS: Skin barrier damage was induced by applying a closed patch of 1% sodium dodecyl sulfate to the forearms of eight participants; they were instructed to apply a barrier cream on a designated damaged area twice daily for 5 days. The SC barrier was evaluated by measuring TEWL and fluorescein sodium salt penetration rate before, immediately after, and 5 days after damage. The penetration rate was assessed using tape-stripping (TS) technique and fluorescence microscopy.
RESULTS: The rates of fluorescein sodium salt penetration into the lower layers of SC differed significantly based on the degree of skin barrier damage. The correlation between penetration rate and TEWL was weak after two rounds of TS and became stronger after subsequent rounds. Five days after skin barrier damage, the penetration rate of all layers differed significantly between areas with and without the barrier cream application.
CONCLUSIONS: Our findings demonstrated that the penetration rate was dependent on skin barrier conditions. The penetration rate and corresponding fluorescence images are suitable quantitative indicators that can visually represent skin barrier conditions.