Y Chemisorbed Phospholipid Monolayers on Gold: Well-Defined and Stable Phospholipid Surfaces for Cell Adhesion Studies

The cell adhesion properties of chemisorbed phospholipid monolayers (CPMs) on gold, prepared from thiol- and disulfide-bearing phosphatidylcholines, have been defined. In the presence of a nonadhesive protein, albumin, adhesion of Chinese hamster ovary (CHO) cells to each CPM surface investigated was minimal; in the presence of fibronectin and vitronectin, substantial adhesion was observed. The ability of CPMs to support adhesion of CHO cells was essentially independent of the molecular structure of the phosphatidylcholine that was employed. Inhibition studies, carried out with GRGDS and with a monoclonal antibody that binds to the fibronectin receptor, provide strong evidence that fibronectin-mediated cell adhesion to CPMs involves a natural ligand-receptor recognition in which the RGD moiety plays a central role. Chemisorbed phospholipid monolayers are proposed as novel surfaces from which to append adhesion-promoting ligands and to investigate, quantitatively, their interaction with cell surfaces.