Characterizing stratum corneum structure, barrier function, and chemical content of human skin with coherent Raman scattering imaging

Abstract

The most superficial layer of the epidermis, the stratum corneum, plays a crucial role in retaining hydration; if its structure or composition is compromised, dry skin may result as a consequence of poor water retention. Dry skin is typically treated with topical application of humectant agents that attract water into the skin. Corneometry, the industry standard for measuring skin hydration, works by assessing the bulk electrical properties of skin. However, this technique samples a large volume of tissue and thus does not resolve the biochemical changes that occur at the cellular level that may underlie mechanisms of dry skin. These limitations can be addressed using coherent Raman scattering (CRS) microscopy to probe the intrinsic vibrational modes of chemical groups such as lipids and water. In the present study, ex vivo human skin explants undergoing dehydration and humectant-induced rehydration were measured via CRS imaging and corneometry. Corneometry data and chemically specific images were obtained from the stratum corneum of each patient sample at each timepoint. The resulting data was statistically analyzed using linear mixed effect model regression analysis. The cellular imaging data revealed water loss in the stratum corneum during dehydration that was correlated with corneometer readings. Interestingly, the imaging data and corneometer readings show differences under the experimental rehydration conditions. The rehydration results suggest that hydration restored by the humectant agents may not be retained by the corneocytes in the ex vivo model system. Given the complementary nature of corneometry, a bulk assessment tool, and CRS microscopy, a modality with subcellular resolution implemented here in an en-face tissue imaging setup, these techniques can be used to measure uptake and efficacy of topical compounds in order to better understand their mode of action and improve therapeutic applications.

Translation of two-photon microscopy to the clinic: multimodal multiphoton CARS tomography of in vivo human skin

“…Besides medical diagnostics, femtosecond or picosecond CARS/SRS on humans [36][37][38] is of interest for the measurement of the intradermal water content, to trace sebaceous glands, and to gain information on the intratissue distribution of topically applied lipid-rich cosmetics and pharmaceutics, including probing the stratum corneum barrier function.…”

Untitled

“…With more calcification in the skin, aging leads to the structural modification in the dermis, degradation of elastic fibers, and variation in the organized state of collagen structure as they are not organized with aging. Aging is a biological and complex theory, which is mainly essential because of its social impact 36 .…”

Исследование эффективноcти оптического просветления кожи растворами глицерина методом конфокальной микроспектроскопии комбинационного рассеяния света

“…В настоящее время большое количество оптических методов активно применяются in vivo для неинвазивной диагностики кожи, а также мониторинга проникновения в кожу и действия лекарственных препаратов и косметических средств [1,2]. К данным методам относятся конфокальная микроспектроскопия комбинационного рассеяния (КМКР) света [3][4][5][6][7], мультифотонная томография [8,9], инфракрасная спектроскопия [10][11][12], оптическая когерентная томография (ОКТ) [13][14][15], отражательная спектроскопия [16,17], флуоресцентная спектроскопия [18,19], терагерцовая спектроскопия [20,21] и другие методы [22]. Все вышеперечисленные оптические методы исследования кожи имеют принципиальное ограничение, не позволяющее получать информацию хорошего качества из глубоких слоев кожи.…”