Presentation Information
[8a-N206-6]Quantitative analysis of mechanical properties in adherent animal cells by AFM analysis based on elastic shell theory
〇(D)Emi Kurnia Sari1, Yuka Tsuri1,2, Naomi Tanga1,3, Jun Muto4, Yoichiroh Hosokawa1,2,3 (1.Div.Mat.Sci.,NAIST, 2.MLC, NAIST, 3.CDG, NAIST, 4.Fujita Health Univ.)
Keywords:
cultured animal cell,nano-indentation,force-curve evaluation
The understanding of the mechanics is indispensable to analyze the mechanical properties of cells. Recently, we established a new method to analyze the mechanical properties of plant cells by atomic force microscopy (AFM). We considered the precise mechanics in cell based on elastic shell theory (EST), in which the cell wall was treated as "shell" closing the cell, and quantified the mechanical properties using the AFM topographic imaging and indentation test. In this study, this method was applied to adherent animal cell, a mouse fibroblast cell (NIH3T3 cell). An AFM cantilever with spherical tip with diameter of 6.62 µm was used for the measurement. The topographic image of NIH3T3 cell were used to obtain curvature of the cell. Next, an AFM indentation test was performed at the center of this cell, obtaining the force-indentation curve. The curve increased linearly in the large indentation region (>2.8 µm), though it was nonlinear in the small region. The linear constant is the spring constant of the cell, which is called apparent stiffness (kas). From the cell curvature and the apparent stiffness, we estimated the Young’s modulus of the shell (YMS) and internal pressure of the cell (IPC) to be 37 MPa and 9.8 kPa, respectively. The shape of the animal cell is maintained by viscoelasticity of the substance inside cell. IPC is reasonable as value of the intracellular viscoelasticity. YMS is also presumably reliable as tensional force of the cell membrane. This result suggests that AFM analysis based on EST is promising method for precisely determining the mechanical properties of adherent animal cells.