Aspiration of biological viscoelastic drops

TL;DR

This paper introduces a new method using micropipette aspiration to analyze the viscoelastic properties of cellular aggregates, revealing how surface tension varies with applied force due to mechanosensing.

Contribution

It presents a novel viscoelastic model and experimental approach for measuring mechanical properties of cellular aggregates, highlighting force-dependent surface tension.

Findings

Surface tension increases with applied force.

Distinct elastic and viscous deformation regimes observed.

Mechanosensing influences cellular aggregate mechanics.

Abstract

Spherical cellular aggregates are in vitro systems to study the physical and biophysical properties of tissues. We present a novel approach to characterize the mechanical properties of cellular aggregates using micropipette aspiration technique. We observe an aspiration in two distinct regimes, a fast elastic deformation followed by a viscous flow. We develop a model based on this viscoelastic behavior to deduce the surface tension, viscosity, and elastic modulus. A major result is the increase of the surface tension with the applied force, interpreted as an effect of cellular mechanosensing.