Is it appropriate to apply Hertz model to describe cardiac myocytes' mechanical properties by atomic force microscopy nanoindentation?

• Published in: Micro & nano letters Vol. 9; no. 3; pp. 153 - 156
• Main Authors: Soufivand, A.A, Navidbakhsh, M, Soleimani, M
• Format: Journal Article
• Language: English
• Published: Stevenage The Institution of Engineering and Technology 01.03.2014; John Wiley & Sons, Inc
• Subjects: Adhesion; AFM indentation depth; AFM indentation force; Atomic force microscopy; atomic force microscopy nanoindentation; biological techniques; biomechanics; cardiac myocyte mechanical property measurement; cardiology; cell adherence; cellular biophysics; contact mechanics; elastic moduli; Elastic modulus; elastic modulus extracting method; Hertz model application; hyperelastic models; Indentation; Mathematical models; Mechanical properties; Modulus of elasticity; muscle; nanoindentation; nanoscale precision; Nanostructure; nonlinear elastic behaviour; viscosity; viscous dissipation; viscous properties; elastic modulus extracting method; nonlinear elastic behaviour; viscous properties; cellular biophysics; elastic moduli; viscous dissipation; nanoindentation; biomechanics; adhesion; Hertz model application; contact mechanics; atomic force microscopy; cardiology; hyperelastic models; viscosity; cell adherence; AFM indentation force; muscle; biological techniques; cardiac myocyte mechanical property measurement; atomic force microscopy nanoindentation; nanoscale precision; AFM indentation depth
• ISSN: 1750-0443; 1750-0443
• DOI: 10.1049/mnl.2014.0019

An analysis is conducted of application of the Hertz model for measuring the cardiac myocytes' mechanical properties. Atomic force microscopy (AFM) was used, which characterises the cellular mechanical properties at a nanoscale precision. The Hertz model, the most common model in contact mechanics, was applied to the experimental data and an elastic modulus was determined by analysing the relationship between the AFM indentation force and the depth. To determine the Hertz model appropriateness accurately, the contribution of the viscous properties, the cell adherence and the elastic modulus extracting method were examined. The elastic moduli were 48.08 ± 2.26 kPa and 55.67 ± 2.56 kPa, respectively, with two different evaluation approaches. The cardiac myocyte exhibited a nonlinear elastic behaviour since the elastic modulus determined by the Hertz model was not constant in the different indentation depths. Furthermore, the viscous dissipation was negligible; therefore the mechanical behaviour of this cell type can be well described by appropriate hyperelastic models.