Aptamers, capture molecules(oligonucleotides) for endothelial progenitor cells(EPCs), are able to recognize circulating EPCs and to bind them. To evaluate effects of the aptamer-coated stent, six pigs were utilized and three different stents-cobalt-chromium bare-metal stent(CC), paclitaxel-eluting Taxus stent(Boston Scientific, Natick, Massachusetts)(TA), and aminoparylene and aptamer-coated stent (AA)-were implanted in the three epicardial
coronary arteries in a random fashion at 8 to 10 atm. Stent length and diameter was 18 mm and 3 mm. After one month, the animals underwent follow-up coronary angiography with acetylcholine(10 mL, 3 ug/mL) stimulation test and were euthanized for histologic analysis. There was a decrease in MLD in all stents: CC(12.3 ?5.5%), TA(10.4 ?3.7%), and AA(11.2 ?6.3%). There was, however, no statistical difference between the groups. Neointimal thickness was lower in TA. During the acetylcholine stimulation test, severe spasm (total occlusion) was noted in 1 pig at the proximal and distal edges of the Taxus stent. Re-endothelialization score was 3.40 ?0.52, 1.33 ?0.52, and 3.60 ?0.55 in CC, TA, and AA, respectively. Thrombus appearance rate was 0/6, 4/6, and 1/6 in CC, TA, and
AA, respectively. The AA showed a tendency toward lower incidence of stent thrombosis and endothelial dysfunction than TA. However, the inhibition of neointimal hyperplasia was not different between CC and AA.