The bio/materials interface

A combination of five materials/techniques has provided a new set of tools to use in examining and controlling the interaction of biological systems with man-made materials: 1. Self-assembled monolayers (SAMs) of alkanethiolates on gold, to control the character of the interface; 2. "Inert surfaces" (surfaces that do not adsorb proteins and therefore do not allow cells to attach); 3. Surface plasmon resonance (SPR), a technique that makes it possible to observe the kinetics and infer the thermodynamics of adsorption of proteins and other biological macromolecules at the surface of SAMs; 4. Soft lithography, to pattern the interface in its plane; 5. Controlled, laminar flows in microchannels, which provide the basis for methods both of fabrication inside capillaries and for controlling the environment of cells in these capillaries. This talk discusses the use of this set of tools in understanding the interaction of proteins with engineered surfaces, and in using surfaces and media patterned in ways that help to explore the interactions of mammalian and microbial cells with these surfaces. Perhaps surprisingly, the former subject has been the more difficult: one does not yet fully understand the mechanism of adsorption of proteins on surfaces. The latter, although still in an early stage of development, shows clear promise of allowing the metabolisms of cells to be manipulated through design of the characteristics of the surface to which they are attached.