Institute for Mechanical Systems, ETH Zürich, Zurich, Switzerland.
Department of Dermatology, University Hospital Zürich, Zurich, Switzerland.
Biomech Model Mechanobiol. 2024 Aug;23(4):1121-1136. doi: 10.1007/s10237-024-01827-5. Epub 2024 Mar 15.
The present study investigates the multiphasic nature of the mechanical behavior of human dermis. Motivated by experimental observations and by consideration of its composition, a quadriphasic model of the dermis is proposed, distinguishing solid matrix components, interstitial fluid and charged constituents moving within the fluid, i.e., anions and cations. Compression and tensile experiments with and without change of osmolarity of the bath are performed to characterize the chemo-mechanical coupling in the dermis. Model parameters are determined through inverse analysis. The computations predict a dominant role of the permeability in the determination of the temporal evolution of the mechanical response of the tissue. In line with the previous studies on other tissues, the analysis shows that an ideal model based on Donnan's equilibrium overestimates the osmotic pressure in skin for the case of very dilute solutions. The quadriphasic model is applied to predict changes in dermal cell environment and therefore alterations in what is called the "mechanome," associated with skin stretch. The simulations indicate that skin deformation causes a variation in several local variables, including in particular the electric field associated with a deformation-induced non-homogeneous distribution of fixed charges.
本研究探讨了人类真皮的多相力学行为。受实验观察和考虑其组成的启发，提出了一种区分真皮的固相基质成分、间质液和在其中移动的带电成分（阴离子和阳离子）的四相模型。进行了有和没有浴渗透压变化的压缩和拉伸实验，以表征真皮中的化学-机械耦合。通过逆分析确定模型参数。计算预测渗透率在确定组织力学响应的时间演化中起着主导作用。与其他组织的先前研究一致，分析表明，对于非常稀溶液的情况，基于 Donnan 平衡的理想模型高估了皮肤的渗透压。四相模型用于预测真皮细胞环境的变化，因此与皮肤拉伸相关的“力学”的变化。模拟表明，皮肤变形会导致几个局部变量发生变化，特别是与固定电荷变形诱导的非均匀分布相关的电场。
