Polyethylene glycol–grafted polystyrene particles

Abstract Densely pegylated particles that can serve as a model system for artificial cells were prepared by covalently grafting amino polyethylene glycol (PEG, molecular weight 3400 or 5000) onto carboxyl polystyrene particles (PS–COOH) using carbodiimide chemistry. PEG‐modified particles (PS–PEG) were characterized by determination of the PEG surface concentration, ζ‐potential, size, and morphology. Under optimized grafting conditions, a dense “brush‐like” PEG layer was formed. A PEG surface concentration of approximately 60 pmol/cm 2 , corresponding with an average distance between grafted PEG chains of ∼17 Å can be realized. It was shown that grafting of PEG onto PS–COOH reduced the adsorption of proteins from human plasma (85 vol %) in phosphate‐buffered saline up to 90%. © 2004 Wiley Periodicals, Inc. J Biomed Mater Res 70A: 49–58, 2004