Long-Term Effects of Novel Combination Coating Anti-CD34 Antibody Applied on Sirolimus-Eluting Stents.

We investigated whether the combination coating of a novel "prohealing coating" hyaluronan-chitosan (HC) and anti-CD34 antibody applied on an SES (HCASES) can reduce neointimal formation while promoting endothelialization compared to either agent alone. Drug-eluting stents have considerably reduced the incidence of in-stent restenosis compared with bare metal stents. However, the beneficial effect of drug elution is overshadowed by delayed re-endothelialization as well as later "catch-up" proliferation related to the drug. Three different stents: Sirolimus-eluting stents (SES), Genous anti-CD34 antibody stents (GS), and the combination of HC-anti-CD34 antibody with sirolimus-eluting stents (HCASES) were deployed in 54 normal porcine coronary arteries and harvested for scanning electron microscopy (SEM) and histological analysis at 60, 90, and 120 days. At 60 and 90 days, SEM analysis showed stent surface endothelial coverage was nearly completed in the HCASES (87 ± 3%, 95 ± 3%) compared with that in the SES (68 ± 6%, 77 ± 8%, P = 0.03). Histological examination at 90 days showed that the HCASES group had less percentage of stenosis than the GS group (P < 0.05). At 120 days, SEM showed a significantly higher extent of endothelial coverage above struts in the HCASES (96 ± 2%) and the GS (95 ± 3%) as compared with the SES group (66 ± 3%; P = 0.02). The HCASES group showed less stenosis than that in the GS group (P < 0.05), but it was not significantly different from the SES group (P = 0.063). Histological and SEM analyses demonstrate that the HCASES can reduce neointimal formation and inflammation while promoting endothelialization in the long term.