Overview

We are studying the mechanical properties and functions of animal cells. Nonmuscle cells carry out various kinds of mechanical activities as individuals such as locomotion, phagocytosis, and division, and collectively in tissues such as establishment of tissue tone. In these and other processes it is essential for the cell to be able to maintain its shape under imposed stresses or to change its shape to move or do work. Change or retention of cell shape is determined by systems of cytoplasmic filaments (actin microfilaments, microtubules, and intermediate filaments) which collectively are termed the cytoskeleton. Therefore at a molecular level cell mechanics resolves into studies of the structure and function of the cytoskeleton and its component proteins.

To measure the forces by which a cell can maintain or change its shape we have developed methods with which to measure quantitatively the deformability of individual cells adherent to a substratum or the forces developed by and the deformability of cells cultured in collagen matrices. Using these methods we obtain information about both contractile forces generated within cells and about the viscous and elastic forces which resist deformation. Mechanical measurements provide a quantitative assay for the functions and activities of molecules such as myosin, gelsolin, or dystrophin.