Chiral stresses in nematic cell monolayers

Abstract

Recent experiments on monolayers of spindle-like cells plated on adhesive stripe-shaped domains have provided a convincing demonstration that certain types of collective phenomena in epithelia are well described by active nematic hydrodynamics. While recovering some of the hallmark predictions of this framework, however, these experiments have also revealed a number of unexpected features that could be ascribed to the existence of chirality over length scales larger than the typical size of a cell. In this article we elaborate on the microscopic origin of chiral stresses in nematic cell monolayers and investigate how chirality affects the motion of topological defects, as well as the collective motion in stripe-shaped domains. We find that chirality introduces a characteristic asymmetry in the collective cellular flow, from which the ratio between chiral and non-chiral active stresses can be inferred by particle-image-velocimetry measurements. Furthermore, we find that chirality changes the nature of the spontaneous flow transition under confinement and that, for specific anchoring conditions, the latter has the structure of an imperfect pitchfork bifurcation.

12 pages, 5 figures. Version accepted for publication in Soft Matter

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Cited by in corpus (12)

• Topological active matter
• Theory of defect-mediated morphogenesis
• Active viscoelasticity of odd materials
• Active cholesterics: odder than odd elasticity
• Integer topological defects of cell monolayers -- mechanics and flows
• Chirality, anisotropic viscosity and elastic anisotropy in three-dimensional active nematic turbulence
• Active Nematic Multipoles: Flow Responses and the Dynamics of Defects and Colloids
• Cells around the corner
• Motility and self propulsion of active droplets
• Active screws: Emergent active chiral nematics of spinning self-propelled rods
• Hydrodynamic stability and pattern formation in hexatic epithelial layers
• Collective epithelial migration mediated by the unbinding of hexatic defects