School of Material Science and Engineering, Shanghai Jiao Tong University, Shanghai, China.
Instrumental Analysis Center, Shanghai Jiao Tong University, Shanghai, China.
Microsc Res Tech. 2022 Mar;85(3):882-891. doi: 10.1002/jemt.23957. Epub 2021 Oct 27.
Colloidal probes have been increasingly demanded for the characterization of cellular modulus in atomic force microscope because of their well-defined geometry and large contact area with cell. In this work, submicron colloidal probes are prepared by scanning electron microscope/focused ion beam and compared with sharp tip and micron colloidal probe, in conjunction with loading velocity and indentation depth on the apparent elastic modulus. NIM and cartilage cells are used as specimens. The results show that modulus value measured by sharp tip changes significantly with loading velocity while remains almost stable by colloidal probes. Also, submicron colloidal probe is superior in characterizing the modulus with increasing indentation depth, which could help reveal the mechanical details of cellular membrane and the modulus of the whole cell. To test the submicron colloidal probe further, the modulus distribution map of cell is scanned with submicron colloidal probe of 50 nm radius during small and large indentation depths with high spatial resolution. The outcome of this work will provide the effective submicron colloidal probe according to the effect of loading velocity and indentation depth, characterizing the mechanical properties of the cells.
胶态探针由于其具有良好的几何形状和与细胞的大面积接触，因此在原子力显微镜中越来越多地用于细胞模量的特性描述。在这项工作中，通过扫描电子显微镜/聚焦离子束制备了亚微米胶态探针，并结合加载速度和压痕深度与细胞的表观弹性模量进行了比较。使用 NIM 和软骨细胞作为标本。结果表明，与胶态探针相比，由尖锐探针测量的模量值随加载速度的变化而显著变化。此外，亚微米胶态探针在增加压痕深度时在表征模量方面具有优势，这有助于揭示细胞膜的力学细节和整个细胞的模量。为了进一步测试亚微米胶态探针，在小和大压痕深度下，以高空间分辨率用 50nm 半径的亚微米胶态探针扫描细胞的模量分布图谱。这项工作的结果将根据加载速度和压痕深度的影响提供有效的亚微米胶态探针，以表征细胞的力学特性。
