Hydration of the outermost layer of human skin, the stratum corneum (SC), affects barrier function, physical appearance, and sensory perception of skin. Water loss, ubiquitously associated with dry skin conditions, results in the development of mechanical tensile stresses that lead to the perception of skin tightness and provide a driving force for damage in the form of chapping or cracking. Restorative moisturizing formulations contain molecular components that counteract the effects of water loss. However, the quantitative connection between water loss and SC mechanical behavior together with a predictive model has remained elusive. We develop a diffusional-based mechanics model that accurately predicts the SC mechanical behavior during hydration or dehydration over a wide range of ambient humidity conditions and presence of moisturizing ingredients. The model was validated with published studies including SC water diffusion, quantitative Raman spectroscopy, and mechanical property and stress characterization. The roles of mobile and partially bound water states are included together with one humectant and three cosmetic emollient molecules commonly used in moisturizing formulations. The model accurately predicts the effects of moisture content and moisturizer ingredients on SC mechanical behavior and provides a quantitative predictive capability that can be employed in the design of efficacious treatments.

人体皮肤最外层角质层（SC）的水合会影响屏障功能，物理外观和皮肤的感官知觉。与皮肤干燥状况普遍相关的水分流失会导致机械拉伸应力的发展，从而导致皮肤紧绷感，并以裂或开裂的形式提供破坏的驱动力。补水保湿配方中包含的分子成分可抵消水分流失的影响。但是，水的流失和SC力学行为之间的定量联系以及预测模型仍然难以捉摸。我们开发了一种基于扩散的力学模型，该模型可以准确预测在各种环境湿度条件下和存在保湿成分的情况下，在水合或脱水过程中的SC力学行为。该模型已通过包括SC水扩散，定量拉曼光谱以及力学性能和应力表征在内的已发表研究进行了验证。流动和部分结合的水态的作用与一种保湿剂和三种化妆品润肤剂分子（通常用于保湿配方）一起被包括在内。该模型可准确预测水分含量和保湿成分对SC机械性能的影响，并提供可用于有效治疗设计的定量预测能力。该模型已通过包括SC水扩散，定量拉曼光谱以及力学性能和应力表征在内的已发表研究进行了验证。流动性和部分结合的水态的作用与一种保湿剂和三种化妆品润肤剂分子（通常用于保湿配方）一起被包括在内。该模型可准确预测水分含量和保湿成分对SC机械性能的影响，并提供可用于有效治疗设计的定量预测能力。该模型已通过包括SC水扩散，定量拉曼光谱以及力学性能和应力表征在内的已发表研究进行了验证。流动和部分结合的水态的作用与一种保湿剂和三种化妆品润肤剂分子（通常用于保湿配方）一起被包括在内。该模型可准确预测水分含量和保湿成分对SC机械性能的影响，并提供可用于有效治疗设计的定量预测能力。