Adsorbed Proteins on Biomaterials

When a synthetic biomaterial comes in contact with a protein-containing biological fluid (e.g., blood plasma or interstitial fluid), proteins rapidly adsorb to the exposed surfaces of the biomaterial to form a complete monolayer of adsorbed protein within a matter of seconds. Cells that subsequently come in contact with the biomaterial surface thus do not actually directly interact with the biomaterial itself, but rather they interact with this adsorbed layer of protein. Thus the bioactivity of the biomaterial surface, and the resulting cellular response, is not directly mediated by the biomaterial itself, but by how the biomaterial surface influences the types of proteins that adsorb onto the biomaterial surface as well as their orientation and conformation on the surface. This chapter presents an overview of the important principles that influence protein adsorption to biomaterial surfaces and how this in turn influences cellular response, with numerous examples from both experimental and theoretical studies that demonstrate these types of interactions.