Rheological properties of the Eukaryotic cell cytoskeleton

The mechanical properties of cells are dominated by the cytoskeleton, a crosslinked network of protein filaments. Unlike synthetic polymer networks, the cell cytoskeleton is a highly dynamical system due to the on-off kinetics of the crosslinking proteins and the polymerization-depolymerization cycles of the filaments themselves. More remarkably, some of the crosslinkers are motor proteins, which are capable of generating forces and directional motion between the filaments by consuming chemical energy. Thus, the cell cytoskeleton is a highly complex and active polymer gel, which is responsible for the unique cell mechanical properties, which make it crawl, divide and assemble to higher functional units. This complexity of the cytoskeleton demands the development of novel experimental techniques as well as theoretical ideas. This review will deal with the recent technological, experimental and theoretical developments in the field of cell mechanics, and current trends. It will be shown that despite the cytoskeletal complexity, cells show some very general rheological properties. (c) 2007 Elsevier B.V. All rights reserved.