Fluorine ion-implanted polystyrene improves growth and viability of vascular smooth muscle cells in culture

Vascular smooth muscle cells derived from the rat aorta were cultured on un modified or F+ ion-implanted polystyrene (5 x 10(12) or 5 x 10(14) ions/cm( 2), energy 150 keV). In 1-day-old cultures, the cells adhered to the modifi ed polystyrene in higher numbers and over larger contact areas. Increased r esistance of the cells to trypsin-mediated detachment from the growth suppo rt indicated an improved adhesion of cells to the modified polymer at later culture intervals. The cells cultured on ion-modified polymers also were l arger and had a higher total protein content. By use of immunocytochemistry , several specific protein species were increased, including the cytoskelet al alpha-actin and vimentin and the plasma membrane-associated vinculin, ta lin, alpha-v integrins, ICAM-1, and VCAM-1, which account for stronger cell -cell and cell-extracellular matrix adhesion. The lower number of cells fou nd floating in the medium suggests that the spontaneous detachment of cells from the modified polystyrene was lower and that the viability of the adhe red cell population was higher. As was shown by the two-parameter flow-cyto metric measurements of BrdU incorporation and DNA content, as well as by H- 3-thymidine autoradiography, the cell proliferation on samples modified by the dose of 5 x 10(12) ions/cm(2) was similar to that in controls; and at t he dose of 5 x 10(14) ions/cm(2), it tended to be even lower. The cells gro wn on the polymer implanted with the dose of 5 x 10(12) ions/cm(2) responde d to a new artificially created cell-free area in a confluent cell layer by more intense migration whereas at the dose of 5 x 10(14) ions/cm(2), the m igration ability of cells was similar to that on the unmodified polymer. Th e data revealed a higher biocompatibility of ion-implanted polystyrene with vascular smooth muscle cells in culture. There was better adhesion, differ entiation, and survival, and there was neither excessive migration nor prol iferation. (C) 2000 John Wiley & Sons, Inc.