Surface modification by silver-negative-ion implantation for controlling cell-adhesion properties of polystyrene

Abstract

Silver-negative ions were implanted into polystyrene (Corning, untreated polystyrene dish). Negative ions were used for implantation to avoid charging problems on the insulator surface. Polystyrene dishes were implanted with Ag − at various ion energies of 5, 10, 20, and 30 keV, with a constant ion dose of 3.0×10 15 ions cm −2 at a current density of about 100 nA cm −2 in a residual gas pressure under 1×10 −3 Pa. Human umbilical vascular endothelial cells (HUVEC) were cultured on these polystyrene dishes in a culture medium based on Medium 199 with 5% CO 2 in air after sterilization. Although there was no observation of cell-adhesion on unimplanted polystyrene, HUVEC attached and grew on Ag-implanted polystyrene dishes by spreading pseudopodia from the cell body. Excellent results were obtained at 20 keV. Among these samples, the greater the ion energy for implantation, the greater the cell-adhesion property, except for at 30 keV. The implantation-energy dependence of the cell-adhesion property of polystyrene corresponded well to that of the contact angle.