Laser-induced surface deformation microscope for the study of the dynamic viscoelasticity of plasma membrane in a living cell
Laser-induced surface deformation microscope for the study of the dynamic viscoelasticity of plasma membrane in a living cell
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DOI：
10.1039/c7an01620d
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发表时间：
2018-05-21
期刊：
影响因子：
4.2
通讯作者：
Yui, Hiroharu
中科院分区：
文献类型：
--
作者：
Morisaku, Toshinori;Yui, Hiroharu
研制了一种激光诱导表面变形显微镜，并应用于测量活细胞质膜的动态弛豫响应。激光束紧密聚焦在细胞表面的任选区域上，并且聚焦的光通过辐射压力在表面上诱导微观变形。LISD显微镜不仅允许非接触和无破坏的测量，而且根据激光束强度的频率提供表面响应的功率谱。LISD的光学系统通过显微镜装备，使我们能够测量质膜亚细胞大小区域的弛豫反应。此外，由表面变形的辐射压力引起的强迫振荡将所获得的功率谱中的频率范围的上限扩展到10（6）Hz，这使得我们能够测量质膜内的局部区域中的弛豫响应。从在较高频率下的幂律指数的差异，认识到癌细胞比正常成纤维细胞服从较弱的单一幂律。此外，角质形成细胞的功率谱服从具有两个指数的幂律，这表明需要常规软玻璃状流变学模型的替代机械模型（其中单个幂律解释细胞在约10（3）Hz以下的响应）来理解更宽的频率范围。LISD显微镜将有助于微观细胞流变学的研究，这对于阐明细胞迁移和组织构建的机制非常重要。
A laser-induced surface deformation (LISD) microscope is developed and applied to measurement of the dynamic relaxation responses of the plasma membrane in a living cell. A laser beam is tightly focused on an optional area of cell surface and the focused light induces microscopic deformation on the surface via radiation pressure. The LISD microscope not only allows non-contact and destruction-free measurement but provides power spectra of the surface responses depending on the frequency of the intensity of the laser beam. An optical system for the LISD is equipped via a microscope, allowing us to measure the relaxation responses in sub-cellular-sized regions of the plasma membrane. In addition, the forced oscillation caused by the radiation pressure for surface deformation extends the upper limit of the frequency range in the obtained power spectra to 10(6) Hz, which enables us to measure relaxation responses in local regions within the plasma membrane. From differences in power-law exponents at higher frequencies, it is realized that a cancerous cell obeys a weaker single power-law than a normal fibroblast cell. Furthermore, the power spectrum of a keratinocyte cell obeys a power-law with two exponents, indicating that alternative mechanical models to a conventional soft glassy rheology model (where single power-laws explain cells' responses below about 10(3) Hz) are needed for the understanding over a wider frequency range. The LISD microscope would contribute to investigation of microscopic cell rheology, which is important for clarifying the mechanisms of cell migration and tissue construction.