Chain-length dependence of the protein and cell resistance of oligo(ethylene glycol)-terminated self-assembled monolayers on gold

Oligo(ethylene glycol) (O-EG(n))-terminated alkanethiol surface-assembled m onolayers (SAMs) have been reported to demonstrate protein-resistant proper ties similar to those of poly(ethylene glycol) (PEG). In this study, we com pared the relative protein resistance of short and long ethylene oxide chai ns, SAMs of PEG 5000, PEG 2000, O-EG(3) (molecular weight = 120), and O-EG( 6) (molecular weight = 240), on gold surfaces. Surface plasmon resonance sh owed that these monolayers were all protein-resistant within the uncertaint y of the measurement. However, they exhibited different adhesive properties toward 3T3 mouse fibroblast adhesion in supplemented Dulbecco's modified E agles medium. The results show that the cell adhesion was sensitive to the concentration of proteins supplemented in the culture medium and to the len gth of PEG chains. (C) 2001 John Wiley & Sons, Inc.