VISCOELASTIC PROPERTIES OF INTACT HUMAN-SKIN - INSTRUMENTATION, HYDRATION EFFECTS, AND CONTRIBUTION OF STRATUM-CORNEUM

[摘要] Past attempts to relate mechanical properties of the human stratum corneum to its state of hydration or disease condition were hampered by the lack of adequate in vivo methodology. With the technique described herein, viscoelastic properties of the skin surface could be measured in vivo or on excised skin in vitro. This method was sensitive enough to detect changes in the properties of the stratum corneum induced by topically applied agents or by mechanical disruption of it. The viscoelastic data suggested that the outermost layers of the stratum corneum may become dry in vivo despite their proximity to the underlying wet tissue, and that the instrument was sensitive enough to measure the changes that occurred. It also appeared that the in vivo behavior of the stratum corneum was similar to that of isolated stratum corneum membranes which became brittle when they were dried and supple when they were hydrated.