Fig. 5.

Microscale approaches for controlling the in vitro cellular microenvironment. (A) Light microscope images of ES cells patterned on PEG-coated substrates as an example of surface patterning for regulating cell–ECM interactions. (B) A fluorescent image of patterned cocultures depicting control over the degree of heterotypic and homotypic interactions between ES cells and fibroblasts (95). (C) An image of a cell and a schematic diagram of microfluidic methods of regulating cell-soluble signal interactions by flowing two parallel streams of fluids on an individual cell (81).