The invited papers in this book reflect the current understanding of the role mechanics play in the biological system at the molecular, cellular and tissue levels. Topics range from tissue engineering and mechanics to mechanics of cells and biomolecules.

These are the proceedings of an IUTAM Symposium on Cellular, Molecular and Tissue Mechanics, held in the summer of 2008 at Woods Hole, Mass, USA. This groundbreaking meeting brought together mechanicians having an interest in biological systems, with biophysicists and biologists in order to address the mechanical basis of biology at the molecular, cellular and tissue scales. The meeting explored a wealth of phenomena in cell and molecular biology all of which display a breadth of mechanical influences that may seem surprising at first glance to the traditional mechanician. This arena for the application of methods developed in mechanics has not drawn as much attention as more traditional tissue biomechanics. However, biophysicists, and even biologists apply ideas of elasticity and structural mechanics quite widely in studying molecules and cells. Many critical functions of biomolecules and cells are fundamentally mechanical in origin, and the mechanics of many biomolecules demonstrate scaling laws that are non-classical to traditional structural mechanics and elasticity. This compilation of the scientific papers presented at the meeting will prove invaluable to researchers in the mechanics of biology as this field develops in the decades to come and takes its place as an acknowledged and central area in biology.

Mechanics plays a central role in determining form and function in biology. This holds at the cellular, molecular and tissue scales. At the cellular scale, mechanics in?uences cell adhesion, cytoskeletal dynamics and the traction that the cell can generate on a given substrate. All of these in turn - fect the cellular functions of migration, mitosis, phagocytosis, endocytosis and stem cell differentiation among others. Indeed, if cells do not develop the appropriate stresses, they are unviable and die. These aspects of cell mechanics are frequently used by mainstream biologists, as traditional mechanicians may be surprised to learn. There is a growing view that many functions of the cell are mechanical in nature even though chemical signals play crucial roles in the processes. Free energy barriers control transitions between different conformations of vir- ally every macromolecule including DNA, RNA, the adhesion protein integrin, the motor protein myosin, and the proteins vinculin and talin that link the cytoskeleton to focal adhesions. The strain energy can be a signi?cant component of the total free energy barrier. For binding to take place, the macromolecules need to be in conf- mational states that expose chemical groups without steric hinderance. The kinetics of chemical reactions are therefore strongly in?uenced by the conformational strain energy.