Figure 3

Discrepancy between two-dimensional and three-dimensional microenvironments. (A) Cells on a rigid two-dimensional (2D) surface coated with a continuous layer of matrix develop focal adhesions and stress fibers at the basal surface. Cell-matrix interactions are restricted to the planar direction and gradients of secreted factors are absent. (B) Inside a three-dimensional (3D) environment, cells display poorly defined stress fibers due to the softness of biomaterials. Cell adhesions are distributed both in the planar and perpendicular directions with discrete matrix fibrils, and secreted factors can be highly concentrated.