Micromechanical control of cell and tissue development: Implications for tissue engineering

Tissue engineering approaches for repair of diseased or lost organs will require the development of new biomaterials that guide cell behavior and seamlessly integrate with living tissues. Previous approaches to engineer artificial tissues have focused largely on optimization of scaffold polymer chemistry and selection of appropriate biochemical additives (e.g., growth factors, adhesive ligands) to provide effective developmental control. However, recent work has shown that micromechanical forces and local variations of extracellular matrix (ECM) elasticity at the microscale regulate cell and tissue development both in vitro and in vivo. The micromechanical properties of the host tissue microenvironment also play a critical role in control of stem cell lineage switching. Here we discuss how new understanding of the fundamental role that mechanical forces play in tissue development might be leveraged to facilitate the development of new types of biomimetic materials for regenerative medicine, with a focus on the design of injectable materials that can target to injury sites, recruit stem cells and direct cellular self-assembly to regenerate functional tissues and organs in situ. (C) 2007 Published by Elsevier B.V.