Label-Free Imaging of Nanoscale Displacements and Free-Energy Profiles of Focal Adhesions with Plasmonic Scattering Microscopy.
Label-Free Imaging of Nanoscale Displacements and Free-Energy Profiles of Focal Adhesions with Plasmonic Scattering Microscopy.
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DOI：
10.1021/acssensors.1c01938
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发表时间：
2021-11-26
期刊：
影响因子：
8.9
通讯作者：
Wang S
中科院分区：
文献类型：
--
作者：
Zhang P;Zhou X;Wang R;Jiang J;Wan Z;Wang S
细胞粘附在细胞通讯、细胞迁移、细胞增殖和医学植入物与组织的整合中起着关键作用。局灶性粘连在物理上将细胞骨架与细胞外基质连接起来，但直接成像单个局灶性粘连仍然具有挑战性。本研究表明，等离子体散射显微镜（PSM）可以以亚微米级的空间分辨率，以无标记、实时、无创的方式直接成像单焦点粘连。PSM是基于表面等离子体共振（SPR）显微镜技术发展起来的，它的瞬变光照使其不受细胞内结构的干扰。与传统的SPR显微镜不同，PSM可以提供高信噪比和亚微米级的空间分辨率，用于对尺寸小到单个分子的分析物进行成像，从而既可以进行超分辨率横向定位，用于测量纳米级位移，也可以精确跟踪分析物质心与传感器表面之间的垂直距离，用于分析自由能剖面。RBL-2H3细胞的PSM成像（时间分辨率低至微秒）显示，在抗体介导的激活过程中，病灶粘附除了具有定向运动外，还具有随机扩散行为。自由能图也显示出类似的运动趋势，表明细胞可能通过改变粘附结构的结合条件而改变其形态。PSM提供了对单个焦点粘附活动的见解，也可以作为研究细胞/表面相互作用的有前途的工具，例如细胞捕获和检测，以及组织粘附材料筛选。
Cell adhesion plays a critical role in cell communications, cell migration, cell proliferation, and the integration of medical implants with tissues. Focal adhesions physically link the cell cytoskeleton to the extracellular matrix, but it remains challenging to image single focal adhesions directly. Here we show that plasmonic scattering microscopy (PSM) can directly image the single focal adhesions in a label-free, real-time, and non-invasive manner with sub-micrometer spatial resolution. PSM is developed based on surface plasmon resonance (SPR) microscopy, and the evanescent illumination makes it immune to the interference of intracellular structures. Unlike the conventional SPR microscopy, PSM can provide high signal-to-noise ratio and sub-micrometer spatial resolution for imaging the analytes with size down to a single molecule level, thus allowing both the super-resolution lateral localization for measuring nanoscale displacement and precise tracking of vertical distances between analyte centroid and sensor surface for analysis of free energy profiles. PSM imaging of RBL-2H3 cell with temporal resolution down to microseconds shows that the focal adhesions have random diffusion behaviors in addition to their directional movements during the antibody mediated activation process. The free energy mapping also shows a similar movement tendency, indicating that cell may change its morphology by varying the binding conditions of adhesive structures. PSM provides insights into the individual focal adhesion activities and can also serve as a promising tool for investigating the cell/surface interactions, such as cell capture and detection, and tissue adhesive material screening.