Renewed interest in how cells are affected by their physical surroundings has begun to reveal the intimate interplay between the mechanical microenvironment and cell phenotype and behavior. Recent research has provided an insight into the role of biochemical and mechanical cues in two and three dimensions to
effect significant changes at the cell and tissue level[4,10,27, 28,38,95,99-101]. Cells are sensitive to passive and active physical stimuli via external forces (eliciting outside-in signaling) and by forces generated in the cell (inside-out signaling) . External forces occur in vivo through shear stress, extension, or compression [19,64,134]. Internally detected forces, which can be generated and transmitted by motor proteins or sliding filaments within the cytoskeleton, can reorganize the cytoskeleton in response to external stiffness, surface topography, and ligand density [113,151].