Coupled influence of substratum hydrophilicity and surfactant on epithelial cell adhesion

The influence of substratum surface hydrophilicity and of a surfactant on human epithelial cell adhesion and protein adsorption was investigated. Therefore, tissue culture grade polystyrene (TCPS) and bacteriological grade polystyrene (BGPS) substrata were treated with different media, with or without Pluronic F68 [a poly(ethylene oxide) and poly(propylene oxide) triblock copolymer surfactant], and with or without type I collagen as a typical extracellular matrix protein. The conditioned substrata were submitted to XPS analysis and assayed for cell adhesion by inoculating Hep G2 cells in a chemically defined nutritive medium. The presence of collagen at the substratum surface is required to obtain attachment and spreading of Hep G2 cells. With PS substrata, treating with a solution of collagen does not promote cell adhesion if the solution contains Pluronic; XPS data show that this is due either to prevention of collagen adsorption or to its desorption by rinsing. With less hydrophobic TCPS substrata, the presence of Pluronic in the conditioning solution does not preclude cell adhesion, nor collagen adsorption. The effect of BGPS and TCPS substrata on Hep G2 cell adhesion is thus mediated by the presence of a surfactant that affects the adsorption of collagen.