Poroelasticity of cell nuclei revealed through atomic force microscopy characterization

With great potential in precision medical application,cell biomechanics is rising as a hot topic in biology.Cell nucleus, as the largest component withincell, not only contributes greatly to thecell's mechanical behavior, but also serves as the most vital component withincell. However,cell nucleus' mechanics is still far from unambiguous up to now. In this paper, we attempted to characterize and evaluate the mechanical property of isolatedcell nuclei usingAtomic Force Microscopy with a tipless probe. As indicated from typical indentation, changing loading rate andstress relaxation experiment results,cell nuclei showed significant dynamically mechanical property,i.e., time-dependent mechanics. Furthermore, through theoretical analysis,finite element simulation andstress relaxation experiment, the nature of nucleus' mechanics was better described by poroelasticity, rather thanviscoelasticity. Therefore, the essence of nucleus' mechanics was clarified to be poroelastic through a sophisticated analysis. Finally, we estimated the poroelastic parameters for nuclei of two types ofcells through a combination of experimental data andfinite element simulation.

Source: Applied Physics Letters - November 21, 2016 Category: Physics Authors: Fanan Wei, Fei Lan, Bin Liu, Lianqing Liu and Guangyong Li Source Type: research