ABSTRACT
Cell adhesion to extracellular matrices (ECMs) through integrin receptors plays a central role in numerous physiological and pathological processes. Moreover, cell attachment to proteins adsorbed onto material surfaces is important to many biomedical and bio technological applications. In addition to anchoring cells, integrin binding triggers signals that direct cell proliferation and differentiation. In this chapter, we describe a recently developed experimental framework to analyze integrin binding to the ECM protein fibronectin (FN) in terms of binding strength, affinity, and intracellular signaling. Based on the insights obtained from these quantitative analyses, we present two biomolecular strategies for the engineering of surfaces to control integrin binding and cell adhesion in order to direct cell function. The first approach focuses on surfaces presenting welldefined chemistries to control the conformation of adsorbed FN to modulate integrin binding, focal adhesion formation, and gene expression. In a second approach, we have engineered nonadhesive surfaces presenting well-defined ligand densities of recombinant FN fragments to promote the binding of specific integrin receptors. Micropatterning of these surfaces provides control over cell spreading and focal adhesion formation. These surface engineering strategies to control integrin binding and cell function are relevant to basic science studies as well as biomedical and bio technological applications.
