Polymer surface chemistry and a novel attachment mechanism in corneal epithelial cells

The initial attachment reaction of most cultured cell types to polymers is based on a linkage of integrin receptors to serum-derived fibronectin and vitronectin that adsorb onto the polymer surface. Recently isolated corneal epithelial cells have an additional attachment mechanism, known to operate on tissue culture polystyrene, which involves endogenous protein synthesis and an intact system of microtubules. Here, we determine if this novel attachment mechanism is operative on polymers of different surface chemistries. The attachment, growth, and deposition of basement membrane proteins by corneal epithelial cells was compared on two hydrophilic surfaces (tissue culture polystyrene and Primaria) and one relatively hydrophobic surface (unmodified polystyrene). Superior levels of cell attachment were found on the hydrophilic polymers, but cells also attached effectively to the hydrophobic surface. Growth rates showed that the cells were able to overcome the differential effects of polymer surface chemistry during a 7-day time period. Polymer surface chemistry had subtle effects on the temporal pattern of biosynthesis of extracellular matrix proteins likely to be involved in cell adhesion. These results show that effective attachment and growth can occur on a hydrophobic polymer when corneal epithelial cells use the endogenous attachment mechanism.