Cell adhesion to polymeric surfaces: experimental study and simple theoretical approach

In a medium without serum, the initial adhesion of L1210 cells to nonsulfonated and sulfonated polymer surfaces was investigated. In the case of sulfonated polymer surfaces, the relative number of adhering cells strongly increases with an increase of the interfacial surface tension; that is, adhesion strongly depends on the surface density of sulfonic groups. However, in the case of nonsulfonated polymer surfaces, the relative number of adhering cells is high and independent of the interfacial surface tension. To extend the basic knowledge of these phenomena, a semi-empirical quantum chemical computational study was undertaken. Simple probe molecules were chosen that mimic the chemical properties of functional groups present on polymeric surfaces. The energies of interaction between these molecules and ones representing the midchain polypeptide building blocks were calculated. To discuss the steric effects involved in similar interactions on real surfaces, a simple model of polymeric surfaces was proposed. Also the interactions among such surfaces and the short hydrated polypeptide chain were studied at the molecular mechanics level of theory. The derived intermolecular energy parameter was found to change in parallel to the number of adhered cells within the two groups of substrata under study: nonsulfonated and sulfonated. The computational results suggest the possible existence of differently arranged cell membrane protein centers responsible for docking to these two types of surfaces.