Surface Modification of Stent Material: Experimental Study of Adhesion and Migration of Human AorticEndothelial Cells on Stent Material

ABSTRACT

PURPOSE: To evaluate the relative adhesion and migration rate of cultured human aortic endothelial cells onto modified stent material in vitro. MATERIALS AND METHODS: Flat 1 x 1cm square, stainless steel 316 L pieces(600 micrometer thick) were initially glow dis-charged to increase the polarity of the metal and were coated with 1 %polyhydroxyethylmethacrylate to which two different amino acid peptide sequences (GRGDY, GREDVY) were covalentlylinked via an amide to an amino-terminus, thus providing a known orientation of these covalently bound peptides.To stimulate implantation of a stent onto the intact arterial wall, human aortic endothelial cells were seeded andgrown to confluence on thick, firm collagen gel. The peptide coated steel pieces were then implanted on thisendothe-lialized surface and migration of HAEC to the surface was monitored and measured for ten days. The contactangle of steel was measured before and after glow-discharge treatment. RESULTS: Our results indicate that themigration and adhesion rate of HAEC to surfaces bearing either GRGDY or GREDVY adhesive peptide sequences wassignificantly higher than that of uncoated stainless steel. The contact angles of glow-discharged steel (eitherpositive or negative charge) were significantly lower, and this in-dicates the increased wettability of steel. Furthermore, migration to a GREDVY-coated surface was greater than to one coated with GRGDY. CONCLUSION: Theseresults indicate that a specific peptide sequence (GREDVY), together with positive glow-discharge treatment ofsteel can selectively enhance endothelial cell migration to metallic stent material.