The effects of measurement parameters on the cancerous cell nucleus characterisation by atomic force microscopy in vitro

Abstract

Cancer is now responsible for the major leading cause of death worldwide. It is noteworthy that lung cancer has been recognised as the highest incidence (11.6%) and mortality (18.4%) for combined sexes among a variety of cancer diseases. Therefore, it is of great value to investigate the mechanical properties of lung cancerous cells for early diagnosis. This paper focus on the influence of measurement parameters on the measured central Young's moduli of single live A549 cell in vitro based on the force spectroscopy mode of atomic force microscopy (AFM). The effects of the measurement parameters on the measured central Young's moduli were analysed by fitting the force–depth curves utilising the Sneddon model. The results revealed that the Young's moduli of A549 cells increased with the larger indentation force, higher indentation speed, less retraction time, deeper Z length and lower purity percentage of serum. The Young's moduli of cells increased first and then decreased with the increasing dwell time. Hence, this research may have potential significance to provide reference for the standardised detection of a single cancerous cell in vitro using AFM methodologies.

Atomic force microscopy in disease‐related studies: Exploring tissue and cell mechanics

“…Indentation depth should not exceed 10% of the sample thickness. Arduino et al, 2022;Chen et al, 2021;Holuigue et al, 2022;Jamal et al, 2022;Liu et al, 2019;Tang et al, 2019 Parabolic Deptula et al, 2021;Han et al, 2022;Nardini et al, 2022;Nguyen & Liu, 2022;Offroy et al, 2020;Sun et al, 2021;Zhu et al, 2020;Zhu et al, 2021;Zhu et al, 2022;Zhu, Tian, et al, 2023 Pyramidal Any axisymmetric shape…”

Multi‐scale characterization and analysis of cellular viscoelastic mechanical phenotypes by atomic force microscopy

“…The measurement results of cell mechanics not only depend on the growth status of cells and the measurement location, but also on the type of probe used and the measurement parameters such as the loading rate and force (Weber et al, 2019; Weber et al, 2021). The association between the Young's modulus of living cells and the loading speed has been extensively investigated, and the Young's modulus increases with the increase in the loading speed (Martens & Radmacher, 2008; Zhu et al, 2022). In addition, cell mechanics are affected by the sensitivity of the instrument used, the modulus of elasticity, and the shape and size of the probe tip.…”

“…The association between the Young's modulus of living cells and the loading speed has been extensively investigated, and the Young's modulus increases with the increase in the loading speed (Martens & Radmacher, 2008;Zhu et al, 2022). In addition, cell mechanics are affected by the sensitivity of the instrument used, the modulus of elasticity, and the shape and size of the probe tip.…”

Metabolically intact nuclei are fluidized by the activity of the chromatin remodeling motor BRG1

“…The nucleus is generally considered the stiffest organelle of the cell 1–5 , with its deformation being the limiting factor in the ability of cells to squeeze through tight spaces of the crowded cellular environment. Measurements of nuclear stiffness, usually by atomic force microscopy or micro aspiration, show that apparent nuclear stiffness is weakly dependent on deformation rate and increases with increasing force, and provide values on the order of 5 to 10 kilopascal for the Young’s modulus 6 7 8 , which is significantly greater than the stiffness of the cell’s actin-based cortex and orders of magnitude stiffer than whole suspended cells and the perinuclear or cytoplasmic volume of the cell, commonly reported to have elastic moduli on the order of 100 Pa 9–11 . This model of a rigid nucleus sitting within a soft cell interior is inconsistent with the fact that cells can deform the spherical nucleus to a highly elongated shape when a cell is embedded within soft polymer networks such as those formed by a few milligrams per milliliter of collagen 12 .…”