Microengineering of cellular interactions

Tissue function is modulated by an intricate architecture of cells and biom olecules on a micrometer scale. Until now, in vitro cellular interactions w ere mainly studied by random seeding over homogeneous substrates. Although this strategy has led to important discoveries, it is clearly a nonoptimal analog of the in vivo scenario. With the incorporation-and adaptation-of mi crofabrication technology into biology, it is now possible to design surfac es that reproduce some of the aspects of that architecture. This article re views past research on the engineering of cell-substrate, cell-cell, and ce ll-medium interactions on the micrometer scale.