Forces at the scale of the cell

TL;DR

This review explores how forces at the cellular level influence biological processes, emphasizing the integration of biophysics, active matter theory, and experimental methods to understand cell mechanics and function.

Contribution

It synthesizes current knowledge on cell-scale forces, introduces active matter frameworks, and highlights methodological advances for studying non-equilibrium biological systems.

Findings

Cell forces influence tissue shape and function

Active matter models help describe non-equilibrium cellular processes

New measurement techniques enable detailed force analysis in cells

Abstract

The importance of molecular-scale forces in sculpting biological form and function has been acknowledged for more than a century. Accounting for forces in biology is a problem that lies at the intersection of soft condensed matter physics, statistical mechanics, computer simulations and novel experimental methodologies, all adapted to a cellular context. This review surveys how forces arise within the cell. We provide a summary of the relevant background in basic biophysics, of soft-matter systems in and out of thermodynamic equilibrium, and of various force measurement methods in biology. We then show how these ideas can be incorporated into a description of cell-scale processes where forces are involved. Our examples include polymerization forces, motion of molecular motors, the properties of the actomyosin cortex, the mechanics of cell division, and shape changes in tissues. We show how new conceptual frameworks are required for understanding the consequences of cell-scale forces for biological function. We emphasize active matter descriptions, methodological tools that provide ways of incorporating non-equilibrium effects in a systematic manner into conceptual as well as quantitative descriptions. Understanding the functions of cells will necessarily require integrating the role of physical forces with the assimilation and processing of information. This integration is likely to have been a significant driver of evolutionary change.