Roy J. Carver Department of Biomedical Engineering, College of Engineering, University of Iowa, Iowa City, IA 52242.
Department of Biomedical Engineering, University of Arkansas, Fayetteville, AR 72701.
J Biomech Eng. 2022 Apr 1;144(4). doi: 10.1115/1.4052887.
Skin is a complex tissue whose biomechanical properties are generally understood in terms of an incompressible material whose microstructure undergoes affine deformations. A growing number of experiments, however, have demonstrated that skin has a high Poisson's ratio, substantially decreases in volume during uniaxial tensile loading, and demonstrates collagen fiber kinematics that are not affine with local deformation. In order to better understand the mechanical basis for these properties, we constructed multiscale mechanical models (MSM) of mouse skin based on microstructural multiphoton microscopy imaging of the dermal microstructure acquired during mechanical testing. Three models that spanned the cases of highly aligned, moderately aligned, and nearly random fiber networks were examined and compared to the data acquired from uniaxially stretched skin. Our results demonstrate that MSMs consisting of networks of matched fiber organization can predict the biomechanical behavior of mouse skin, including the large decrease in tissue volume and nonaffine fiber kinematics observed under uniaxial tension.
皮肤是一种复杂的组织，其生物力学特性通常被理解为一种不可压缩的材料，其微观结构发生仿射变形。然而，越来越多的实验表明，皮肤具有较高的泊松比，在单轴拉伸加载过程中体积显著减小，并表现出与局部变形不相符的胶原纤维运动学。为了更好地理解这些特性的力学基础，我们基于机械测试过程中获取的真皮微观结构的多光子显微镜成像，构建了基于微观结构的小鼠皮肤多尺度力学模型（MSM）。研究了三个跨越高度取向、中度取向和几乎随机纤维网络的模型，并将其与从单轴拉伸皮肤获得的数据进行了比较。我们的结果表明，由匹配纤维组织组成的 MSM 可以预测小鼠皮肤的生物力学行为，包括在单轴拉伸下观察到的组织体积大幅减小和非仿射纤维运动学。
