Exploiting the current paradigm of blood-material interactions for the rational design of blood-compatible materials

The paradigm of tissue-material interactions, which holds that protein adso rption is the first event following contact and determines the later intera ctions of cells, is invoked to propose a design strategy for biocompatibili ty, Control of protein interactions is the key element, and it is suggested that nonspecific protein adsorption must be prevented while the adsorption of specific proteins that are expected to result in appropriate bioactivit y must be promoted, Modification with polyethylene oxide has been investiga ted extensively as a means of preventing nonspecific adsorption, Examples o f proteins that could be targeted for specific adsorption are antithrombin III to prevent coagulation and albumin to minimize platelet adhesion, Two e xamples of surfaces designed for specific adsorption from the author's labo ratory are discussed: the incorporation of thrombin binding peptides to giv e a thrombin scavenging surface, and the incorporation of lysine to give a plasminogen specific surface with the potential to dissolve clots.