A new way of manipulating the manner in which cells interact with biomaterials was made possible with the discovery of arginine-glycine-aspartic acid (RGD) as a major cell recognition signal in the extracellular matrix. This RGD signal has been incorporated into synthetic compounds that can function as antagonist or agonist for a class of cell surface receptors called integrins. In the agonist mode, these compounds can be coupled or bound to wide variety of biomaterials to present a target for the physiological interaction of cells with the surface of these materials through one or more of the integrin types expressed on the cell surface. The agonist activity of these compounds is evident from an in vivo response of faster and more complete tissue integration and a reduction in foreign body response. There are more than 25 different integrin subtypes, and different cell types express a unique subset of these on their surface. More than half of the integrins recognize and bind to a form of the RGD signal in their natural ligand and can distinguish one form of RGD from another. Specific tissue responses such as vascualization or mineralization can be achieved by immobilizing compounds with the appropriate integrin specificity.