Enhanced growth of human vascular endothelial cells on negative ion (Ag)‐implanted hydrophobic surfaces

Abstract

Silver negative ions (Ag−) were implanted to an insulator, polystyrene, in a relatively low ion energy ranging from 5 to 30 keV, and in a dose ranging from 1014 to 6 × 1016 ions · cm−2. Surfaces of Ag−-implanted polystyrene were studied by means of secondary ion mass spectrometry, X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, and micro-Raman spectroscopy, and contact angle measurement. As a result of Ag− implantation, the polystyrene surfaces underwent degradation, thereby becoming more hydrophilic with increasing dose and ion energy except an ion energy of 30 keV. The Ag− implantation in polystyrene led to enhanced growth of human vascular endothelial cells, which grew to more extent with increased hydrophilicity of Ag−-implanted surfaces except an ion energy of 30 keV. Polystyrene surfaces on which Ag− were implanted up to an ion energy of 30 keV caused the same hydrophobic level as polystyrene surface itself. Nevertheless, the Ag−-implanted polystyrene showed relatively good biocompatibility different from polystyrene. Such an improvement in cell adhesion may be related to the formation of a graphite-like structure on polystyrene surfaces by a Ag−-implanted process. Moreover, upon plating in a high cell density, human vascular endothelial cells survived even on the polystyrene region of Ag−-implanted polystyrene for longer than 1.5 months, while the cells did not grow on untreated polystyrene in the same culture conditions. © 1999 John Wiley & Sons, Inc. J Biomed Mater Res, 44, 22–30, 1999.