ATTACHMENT OF VERO CELLS TO CORONA-TREATED, PLASTIC SURFACES

Corona treatment of polystyrene (PS) and polyethylene resulted in an i ncrease in the interfacial energy (gamma(sv)) of these surfaces, prima rily due to an increase in the polar forces. The number of Vero cells which attached and the strength of attachment were higher on corona-tr eated surfaces, increasing as gamma(sv) increased. Inoculum concentrat ion did not affect the percentage of cells that attached. Experiments were performed in Dulbecco's modified Eagle's medium containing 10% fe tal bovine serum hence cellular attachment was most likely preceeded b y adsorption of serum proteins. A minimum of 1 h of incubation under s tatic conditions resulted in the maximum number of cells which attache d and which remained attached after shear stress (33.0 dynes/cm(2) for 5 min) was applied. Experimental results with corona treated surfaces agree with the theoretical predictions for the free energy of adhesio n of Vero cells in the medium used, indicating that interfacial energy plays an important role in attachment. The model predicted that subst rates with a gamma(sv)>55.6 ergs/cm(2) (i.e. Theta(H2O)<39 degrees) wo uld have a positive energy of adhesion. Such substrates did have >60% cell attachment. Since the model is valid if only van der Waals and Le wis acid-base interactions are dominant, these forces probably played a major role in the adsorption of serum proteins. Polylysine-treated P S and tissue culture PS did not follow the model. In the first of thes e two cases, electrostatic interactions probably played a more importa nt role since the surface was covered with a positively charged protei n.