Berlin 2024 – scientific programme

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BP: Fachverband Biologische Physik

BP 11: Cell Mechanics I

BP 11.3: Talk

Tuesday, March 19, 2024, 10:15–10:30, H 2032

Mechanical complexity of living cells can be mapped onto simple homogeneous equivalents — •Sebastian Wohlrab, Sebastian Johannes Müller, and Stephan Gekle — Biofluid Simulation and Modeling, Universität Bayreuth, Deutschland

Despite the complex composition of a biological cell with its constituents varying in both size and stiffness, experimental data analysis and numerical simulations often assume a strongly simplified homogeneous cell model. Accordingly, a single elastic modulus is assigned to the entire cell. This ad-hoc simplification has so far mostly been used without proper justification.

With our research we methodically demonstrate that indeed a mechanically heterogeneous cell can effectively be replaced by a homogeneous equivalent cell with a volume averaged elastic modulus. Using computer simulations we investigate a hyperelastic cell with a heterogeneous interior under compression and in shear/channel flow mimicking atomic force and microfluidic measurements, respectively.

We find that the homogeneous equivalent cell reproduces quantitatively the behavior of its heterogeneous counterpart, and that this equality is largely independent of the stiffness or spatial distribution of the heterogeneity. Our results thus validate in hindsight the simplifying approaches taken in many previous experimental and computational works, but also provide a solid basis on which future experimental data can be analyzed and physically reliable computer simulations can be constructed.

Keywords: cell mechanics; atomic force microscopy; cell elasticity; shear flow; cell nucleus