Biophysical Society Thematic Meeting| Aussois 2019

Biology and Physics Confront Cell-Cell Adhesion

Poster Abstracts

20-POS Board 20 A THEORETICAL DESCRIPTION OF FRICTION AND ADHESION OF LIPID BILAYERS Yannick Azhri Din Omar 1 ; 1 University of California, Berkeley, Chemical and Biomolecular Engineering, Berkeley, CA, USA Cell membranes are most often found to be in contact with other objects. For instance, supported lipid bilayers serve as the basis for many experimental setups to study model bilayer systems. In such setups, the lipid bilayer may either be in contact with the solid substrate surface or may be separated from it by a thin water film or polymer cushion. In epithelial sheets, cells are densely packed and pressed against one another. During cell migration, cells employ both adhesive and frictional contact to generate propulsion in different environments. All these phenomena exhibit complex contact behavior. As these examples show, contact between cell membranes, and cell membranes and substrates is ubiquitous. However, current theoretical descriptions are not able to capture the full complexity of such contact. Here, we present the extension of a recently published framework for the irreversible thermodynamics of lipid bilayers to account for contact interactions. The presented theory employs the classical Helfrich model together with viscous surface flow. The extension to contact will first be presented in a general fashion and will then be specialized by the use of particular constitutive contact models for frictional and adhesive contact. We will further show how the effects of ligands on the cell membrane can be modeled. The presented theory is fully general and does not pose any restrictions on the permissible membrane shapes. It can thus serve to understand the effects of cell membrane friction and adhesion, both in-vivo and in-vitro.

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