PEG Hydrophilic Coatings Mechanism of Protein Rejection

PEG surface modification was used to increase biocompatibility (Saw-hney et al, 1993) or to obtain blood-compatible materials (Han et al, 1993). PEG grafting on various substrates was shown to reduce the adsorption of various proteins (Prime and Whitesides, 1993 Llanos and Sefton, 1993) and fibrinogen (Han et al, 1993) to the surface and to reduce complement activation (Kishida et a/., 1992). 

The condihons that lead to protein repulsion from hydrophobic flat surfaces coated with PEG, attached to the substrate at only one chain end, were studied by Jeon et al (1991) and Jeon and Andrade (1991). These authors consider a model in which different forces are taken into account  

Using this model, Jeon and Andrade (1991) suggested that a high PEG surface density and a long PEG chain length are necessary for low protein adsorption and that the effect of surface density predominates over the effect of chain length. 

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