Buganza Tepole Adrián, Gart Michael, Purnell Chad A, Gosain Arun K, Kuhl Ellen
Department of Mechanical Engineering, Stanford University, Stanford, CA, 94305, USA,
Biomech Model Mechanobiol. 2015 Oct;14(5):1007-19. doi: 10.1007/s10237-015-0650-8. Epub 2015 Jan 30.
Skin expansion delivers newly grown skin that maintains histological and mechanical features of the original tissue. Although it is the gold standard for cutaneous defect correction today, the underlying mechanisms remain poorly understood. Here we present a novel technique to quantify anisotropic prestrain, deformation, and growth in a porcine skin expansion model. Building on our recently proposed method, we combine two novel technologies, multi-view stereo and isogeometric analysis, to characterize skin kinematics: Upon explantation, a unit square retracts ex vivo to a square of average dimensions of [Formula: see text]. Upon expansion, the unit square deforms in vivo into a rectangle of average dimensions of [Formula: see text]. Deformations are larger parallel than perpendicular to the dorsal midline suggesting that skin responds anisotropically with smaller deformations along the skin tension lines. Upon expansion, the patch grows in vivo by [Formula: see text] with respect to the explanted, unexpanded state. Growth is larger parallel than perpendicular to the midline, suggesting that elevated stretch activates mechanotransduction pathways to stimulate tissue growth. The proposed method provides a powerful tool to characterize the kinematics of living skin. Our results shed light on the mechanobiology of skin and help us to better understand and optimize clinically relevant procedures in plastic and reconstructive surgery.
皮肤扩张可提供新生长的皮肤，其保持了原始组织的组织学和力学特征。尽管它是当今皮肤缺损修复的金标准，但其潜在机制仍知之甚少。在此，我们提出一种新技术，用于量化猪皮肤扩张模型中的各向异性预应变、变形和生长。基于我们最近提出的方法，我们结合了两种新技术，即多视图立体视觉和等几何分析，来表征皮肤运动学：在取出后，一个单位正方形在体外收缩为平均尺寸为[公式：见原文]的正方形。在扩张时，单位正方形在体内变形为平均尺寸为[公式：见原文]的矩形。平行于背中线的变形大于垂直于背中线的变形，这表明皮肤沿皮肤张力线以较小变形进行各向异性响应。在扩张时，贴片相对于取出的未扩张状态在体内生长了[公式：见原文]。平行于中线的生长大于垂直于中线的生长，这表明拉伸增强激活了机械转导途径以刺激组织生长。所提出的方法为表征活体皮肤的运动学提供了一个强大的工具。我们的结果揭示了皮肤的机械生物学，并帮助我们更好地理解和优化整形和重建手术中的临床相关程序。
