Protein Adsorption on Polymer Particles

Protein adsorption on polymer particles has significant importance in biomedical applications, both in vitro and in vivo. It has, therefore, been studied from all viewpoints for the last two decades, but the results were inconsistent due to its complexity. It is not an exaggeration to say that nobody knows what exactly happens at the interfaces between proteins and particles. Proteins are so large that they cannot be treated as small solutes, and the surface of polymer particles is somewhat hairy, which makes quantification difficult. Furthermore, particles are continuously moving, which makes time-dependent in situ measurement impossible. Protein adsorption on flat and fixed surfaces is relatively easy to analyze; hence, many techniques have been introduced and tested. Although the whole adsorption mechanism is not yet completely analyzed, what is known can give some clues about protein adsorption on polymer particles. Biomedical applications of protein adsorption on polymer particles include the following: artificial tissues and organs, drug delivery systems, biosensors, solid-phase immunoassays, immunomagnetic cell separations, and immobilized enzymes (1–5).