Cell–surface contacts are vital for many eukaryotic cells. The surface provides anchorage (facilitating spreading and proliferation), is involved in sensation, i.e., via mechano-, osmo- and chemoreceptors, and in addition nutrients may also be supplied via vessels adjacent to the basal lamina. Hence, the ability to manipulate the surface characteristics provides a mechanism for directly influencing cell behaviour. Applications such as medical implants and tissue engineering require biocompatible, stable surfaces for controlling cell behaviour. Mucin-coated surfaces inhibit cell spreading compared with poly(L-lysine) in vitro; here, we show that a composite layer assembled from mucin-EGCg aggregates counters the inhibition. Although the anti-spreading effects of the glycoprotein substratum on cell behaviour are similar to those observed for pure polysaccharide surfaces, the reversal of cell spreading inhibition by the admixture of polyphenol/glycoprotein substrata is remarkable and unexpected. Possible applications for a composite glycoprotein–polyphenol layer include medical devices, in particular for those operating at mucosal interfaces such as the oral, tracheal or gastrointestinal tract cavities, wound healing, cancer control and the controlled growth of therapeutic cell cultures.