Cell behaviour on polymer surfaces grafted with non-ionic and ionic monomers.

Following exposure to corona discharge, a polyethylene film was graft polymerized with different water-soluble monomers such as acrylamide (non-ionic), acrylic acid (anionic), 2-acrylamide-2-methyl propane sulphonic acid (anionic), styrene sulphonic acid sodium salt (anionic) and N,N-dimethylaminopropyl acrylamide (cationic). Attachment and proliferation of HeLa S3 cells were studied for grafted surfaces with different zeta potentials and contact angles. The polyethylene surface graft polymerized with styrene sulphonic acid sodium salt exhibited high cell attachment and protein adsorption, whereas the cells did not adhere to the 2-acrylamide-2-methyl propane sulphonic acid graft-polymerized surface, although both surfaces had high negative zeta potentials. Graft polymerization of acrylamide reduced the zeta potential of surface close to zero and rejected the cell attachment. The polyethylene surface became highly cell-adhesive through graft polymerization of the cationic N,N-dimethylaminopropyl acrylamide monomer, but too much grafting killed the attaching cells. Once the cells attached to a surface without being killed, they could proliferate at the same growth rate, whatever their surface zeta potential.