Institute of Applied Physics, University of Tübingen, Auf der Morgenstelle 10, 72076 Tübingen, Germany.
Nanoscale. 2019 Apr 4;11(14):6982-6989. doi: 10.1039/c8nr09428d.
Living cells exhibit complex material properties, which play a crucial role in many aspects of cell function in health and disease, including migration, proliferation, differentiation, and apoptosis. Various techniques exist to probe the viscoelastic material properties of living cells and a frequent observation is a cell-to-cell correlation between average stiffness and fluidity in populations of cells. However, the origin of this correlation is still under discussion. Here, we introduce an imaging technique based on the scanning ion conductance microscope (SICM) to measure the creep compliance of soft samples, which allowed us to generate images of viscoelastic material properties of living cells with high spatial and temporal resolution. We observe a strong subcellular correlation between the local stiffness and fluidity across the individual living cell: stiff regions exhibit lower fluidity while soft regions exhibit higher fluidity. We find that this subcellular correlation is identical to the previously observed cell-to-cell correlation. The subcellular correlation reversibly vanishes after drug-induced disruption of the cytoskeleton, indicating that the subcellular correlation is a property of the intact cytoskeleton of the living cell.
活细胞表现出复杂的材料特性，这些特性在细胞功能的许多方面起着至关重要的作用，包括迁移、增殖、分化和凋亡。存在多种技术来探测活细胞的粘弹性材料特性，经常观察到细胞群体中平均刚度和流动性之间存在细胞间相关性。然而，这种相关性的起源仍在讨论中。在这里，我们引入了一种基于扫描离子电导显微镜（SICM）的成像技术来测量软样品的蠕变柔量，这使我们能够以高时空分辨率生成活细胞粘弹性材料特性的图像。我们观察到单个活细胞中局部刚度和流动性之间存在强烈的亚细胞相关性：硬区域表现出较低的流动性，而软区域表现出较高的流动性。我们发现这种亚细胞相关性与先前观察到的细胞间相关性相同。细胞骨架药物诱导破坏后，这种亚细胞相关性可逆地消失，表明亚细胞相关性是活细胞完整细胞骨架的特性。
