Fibronectin adsorption and cell adhesion to mixed monolayers of tri(ethylene glycol)- and methyl-terminated alkanethiols

Surface chemistries that prevent protein adsorption and render surfaces nonadhesive have emerged as promising biomaterial modifications for minimizing host-implant inflammatory responses and providing a nonspecific background for the presentation of bioactive motifs to elicit directed cellular responses. Oligo(ethylene glycol) moieties (−(CH2CH2O)n−, abbreviated as EGn) have proven to be the most protein-resistant functionality and remain the standard for comparison. In the present study, we analyzed fibronectin (FN) adsorption and cell adhesion to CH3/EG3 mixed self-assembled monolayers. In contrast to previous studies with ellipsometry and surface plasmon resonance spectroscopy, we demonstrate significant radiolabeled FN adsorption onto EG3-containing surfaces, including pure EG3 monolayers. These FN-coated surfaces supported FN density-dependent increases in fibroblast adhesion strength. However, while FN adsorbed irreversibly to CH3-terminated surfaces, adsorbed FN was removed from EG3 monolayers and ...