Nearly all tissue cells in the body reside in the micrometer-sized fibrous meshwork of the extracellular matrix (ECM). The ECM is typically composed of fibronectin (FN), collagen and laminin, and provides complex biochemical and physical signals.^1–3  The ECM not only acts as storage for growth factors and cytokines but also induces cell–cell contacts and cell–matrix interactions.⁴  Accordingly, control of the cellular microenvironment using artificial ECM and growth factors will be important in vitro technique to control cell growth, cytokine expression, stem-cell differentiation, and cellular assembly. To control cellular microenvironment, the patterning of substrate surfaces⁵  and the chemical...