使用锥形原子力显微镜探针精确测定细胞的弹性模量。

Precise determination of elastic modulus of cell using conical AFM probe.

机构信息

State Key Laboratory of Structure Analysis for Industrial Equipment, Department of Engineering Mechanics, Dalian University of Technology, Dalian 116024, China.

出版信息

J Biomech. 2021 Mar 30;118:110277. doi: 10.1016/j.jbiomech.2021.110277. Epub 2021 Jan 30.

DOI:10.1016/j.jbiomech.2021.110277

PMID:33556889

Abstract

The Sneddon formula is conventionally used to calculate the elastic modulus of cell based on atomic force microscope (AFM) experiments. Owing to the disobedience of the formula assumptions, errors exist. Here, the ABAQUS for finite element modeling and analysis was used to simulate the process of compression of cell with a AFM conical probe. It was found that the relative error ranges from 0.094 to 1.455 folds, depending on half angle of the cone, curvature radius at the tip of the cone and the compression depth. By fitting the error data, we proposed a correction factor, which can be multiplied by the Sneddon formula to get a modified formula, providing the more accurate elastic modulus of cell. The experimentally measured elastic moduli of cell and hydrogel are in good agreement with the values obtained using the modified formula.

摘要

斯内登公式通常用于根据原子力显微镜（AFM）实验计算细胞的弹性模量。由于该公式的假设不成立，因此存在误差。在这里，使用 ABAQUS 进行有限元建模和分析来模拟具有 AFM 锥形探针的细胞压缩过程。结果发现，相对误差范围在 0.094 到 1.455 倍之间，具体取决于圆锥的半角、圆锥尖端的曲率半径和压缩深度。通过拟合误差数据，我们提出了一个修正因子，可以乘以斯内登公式得到一个修正公式，从而提供更准确的细胞弹性模量。通过实验测量的细胞和水凝胶的弹性模量与使用修正公式获得的值吻合较好。