![]() ![]() ![]() Both models abstract a viscoelastic system as a composite structure containing an elastic spring connected to a dashpot containing a viscous fluid ( Figure 1B). ![]() On the theoretical level, viscoelasticity was independently modelled by Maxwell and Kelvin in the 19th century. Viscoelastic materials exhibit characteristics of both solids and fluids: at short time scales they deform elastically and, at long timescales, they behave as viscous fluids. Solid-like objects deform shortly and reversibly under constant force, whereas fluid-like objects irreversibly increase their deformation as long as a force is exerted. Viscoelasticity of such materials is evaluated from the degree of deformation upon constant force application and release, an experimental procedure called creep and recovery test ( Figure 1A). Our knowledge of viscoelasticity mainly comes from material sciences, where certain physical parameters are well-defined for non-living materials such as glasses, rubbers, metals and polymers. Advances in biophysical tools measuring viscoelasticity have revealed an essential and physiologically relevant link between material properties and morphogenesis, opening the challenge to now understand how emergent viscoelasticity is regulated by, and in turn, regulates the mechanochemistry of living systems.Ī material is viscoelastic if it displays both viscous and elastic behavior. Tissue-scale viscoelasticity was shown to be important in collective morphogenetic processes such as tissue folding, spreading, wound healing and migration, and it is mainly determined by the interplay of cell-cell and/or cell-extracellular space interactions. Cellular-scale viscoelasticity influences several single-cell functions such a shape, division, and motility, and it is predominantly determined by the physical properties of the underlying cytoskeletal networks. Viscoelasticity allows living systems to preserve a basic architecture due to their solid-like characteristics, but also at the same time to dynamically reorganize in different shapes and patterns due to their viscous-like characteristics. The viscoelastic or material properties of cells and tissues are key regulators of cell and tissue growth, motion, and homeostasis. We propose that the statistical mechanics of networks can be used in the future as a powerful framework to uncover quantitatively the biomechanical basis of viscoelasticity across scales. We then conceptualize viscoelasticity as a network theory problem and discuss its applications in several biological contexts. In this review, we summarize work on the viscoelastic nature of cytoskeletal, extracellular and cellular networks. Linking the changes in the structural or material properties of cells and tissues, such as material phase transitions, to the microscopic interactions of their constituents, is still a challenge both at the experimental and theoretical level. Experimental and theoretical findings suggest that cellular- and tissue-scale viscoelasticity can be understood as a collective property emerging from macromolecular and cellular interactions, respectively. Spatiotemporal changes in viscoelasticity are a key component of the morphogenesis of living systems. 2European Molecular Biology Laboratory, Heidelberg, Germany.1Institute of Biology, Karl-Franzens-University Graz, Graz, Austria. ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |