Koay Eugene J, Shieh Adrian C, Athanasiou Kyriacos A
Rice University, Department of Bioengineering, Houston, TX 77005, USA.
J Biomech Eng. 2003 Jun;125(3):334-41. doi: 10.1115/1.1572517.
An apparatus for creep indentation of individual adherent cells was designed, developed, and experimentally validated. The creep cytoindentation apparatus (CCA) can perform stress-controlled experiments and measure the corresponding deformation of single anchorage-dependent cells. The apparatus can resolve forces on the order of 1 nN and cellular deformations on the order of 0.1 micron. Experiments were conducted on bovine articular chondrocytes using loads on the order of 10 nN. The experimentally observed viscoelastic behavior of these cells was modeled using the punch problem and standard linear solid. The punch problem yielded a Young's modulus of 1.11 +/- 0.48 kPa. The standard linear solid model yielded an instantaneous elastic modulus of 8.00 +/- 4.41 kPa, a relaxed modulus of 1.09 +/- 0.54 kPa, an apparent viscosity of 1.50 +/- 0.92 kPa-s, and a time constant of 1.32 +/- 0.65 s. To our knowledge, this is the first time that stress-controlled indentation testing has been applied at the single cell level. This methodology represents a new tool in understanding the mechanical nature of anchorage-dependent cells and mechanotransductional pathways.
设计、开发并通过实验验证了一种用于单个贴壁细胞蠕变压痕的装置。蠕变细胞压痕装置（CCA）可以进行应力控制实验，并测量单个锚定依赖性细胞的相应变形。该装置能够分辨约1 nN的力和约0.1微米的细胞变形。使用约10 nN的载荷对牛关节软骨细胞进行了实验。利用冲头问题和标准线性固体对这些细胞实验观察到的粘弹性行为进行了建模。冲头问题得出的杨氏模量为1.11±0.48 kPa。标准线性固体模型得出的瞬时弹性模量为8.00±4.41 kPa，松弛模量为1.09±0.54 kPa，表观粘度为1.50±0.92 kPa·s，时间常数为1.32±0.65 s。据我们所知，这是首次在单细胞水平上应用应力控制压痕测试。这种方法代表了一种理解锚定依赖性细胞的力学性质和机械转导途径的新工具。
