EFFECT OF CHAIN DENSITY ON INHIBITION OF PROTEIN ADSORPTION BY POLY(ETHYLENE GLYCOL) BASED COATINGS

The effect of interfacial chain density of poly(ethylene glycol) (PEG) on the adsorption of serum proteins was investigated by in situ ellip sometry. For terminal covalently grafted PEG of molecular weight 5000 an increased grafting density results in decreased serum protein adsor ption. At high interfacial chain density (approximate to 0.1 chain/mm( 2)), efficient protein rejection was observed, irrespective of the cou pling chemistry used. Strongly adsorbed PEG-containing polymers behave d similarly to covalently attached PEG regarding inhibition of protein adsorption, independent of the nature of the underlying surface. The results are discussed in relation to the importance of the protein siz e in protein rejection by PEG coatings. (C) 1998 Academic Press.