McDowell Emily J, Ellerbee Audrey K, Choma Michael A, Applegate Brian E, Izatt Joseph A
Duke University, Department of Biomedical Engineering, Durham, North Carolina 27708, USA.
J Biomed Opt. 2007 Jul-Aug;12(4):044008. doi: 10.1117/1.2753755.
We present spectral domain phase microscopy (SDPM) as a new tool for measurements at the cellular scale. SDPM is a functional extension of spectral domain optical coherence tomography that allows for the detection of cellular motions and dynamics with nanometer-scale sensitivity in real time. Our goal was to use SDPM to investigate the mechanical properties of the cytoskeleton of MCF-7 cells. Magnetic tweezers were designed to apply a vertical force to ligand-coated magnetic beads attached to integrin receptors on the cell surfaces. SDPM was used to resolve cell surface motions induced by the applied stresses. The cytoskeletal response to an applied force is shown for both normal cells and those with compromised actin networks due to treatment with Cytochalasin D. The cell response data were fit to several models for cytoskeletal rheology, including one- and two-exponential mechanical models, as well as a power law. Finally, we correlated displacement measurements to physical characteristics of individual cells to better compare properties across many cells, reducing the coefficient of variation of extracted model parameters by up to 50%.
我们提出了光谱域相显微镜（SDPM），作为一种用于细胞尺度测量的新工具。SDPM是光谱域光学相干断层扫描的功能扩展，能够实时检测具有纳米级灵敏度的细胞运动和动力学。我们的目标是使用SDPM研究MCF-7细胞细胞骨架的力学特性。设计了磁性镊子，以对附着在细胞表面整合素受体上的配体包被磁珠施加垂直力。使用SDPM解析由施加应力引起的细胞表面运动。展示了正常细胞以及因用细胞松弛素D处理而肌动蛋白网络受损的细胞对施加力的细胞骨架反应。将细胞反应数据拟合到几种细胞骨架流变学模型，包括单指数和双指数力学模型以及幂律模型。最后，我们将位移测量与单个细胞的物理特征相关联，以便更好地比较多个细胞的特性，将提取模型参数的变异系数降低了多达50%。
