Anti-CD34 Antibodies Immobilized on the Surface of Sirolimus-Eluting Stents Enhance Stent Endothelialization

Objectives In this study, we hypothesized that an antihuman-CD34 antibody immobilized on the surface of commercially available sirolimus-eluting stents (SES) could enhance re-endothelialization compared with SES alone. Background Previous experience with antihuman-CD34 antibody surface modified Genous stents (GS) (OrbusNeich Medical, Fort Lauderdale, Florida) has shown enhanced stent endothelialization in vivo. Methods In the phase 1 study, stents were deployed in 21 pig coronary arteries for single stenting (9 vessels: 3 GS, 3 SES, and 3 bare-metal stents) and overlapping stenting with various combinations (12 vessels: 4 GS+GS, 4 SES+SES, and 4 GS+SES) and harvested at 14 days for scanning electron and confocal microscopy. In phase 2, immobilized anti-CD34 antibody coating was applied on commercially available SES (SES–anti-CD34, n = 7) and compared with GS (n = 8) and SES (n = 7) and examined at 3 and 14 days by scanning electron/confocal microscopy analysis. Results In phase 1, single stent implantation showed greatest endothelialization in GS (99%) and in bare-metal stent (99%) compared with SES (55%, p = 0.048). In overlapping stents, endothelialization at the overlapping zone was significantly greater in GS+GS (95 ± 6%) and GS+SES (79 ± 5%) compared with the SES+SES (36 ± 14%) group (p = 0.007). In phase 2, SES–anti-CD34 resulted in increased endothelialization compared with SES alone at 3 days (SES–anti-CD34 36 ± 26%; SES 7 ± 3%; and GS 76 ± 8%; p = 0.01), and 14 days (SES–anti-CD34 82 ± 8%; SES 53 ± 20%; and GS 98 ± 2%; p = 0.009). Conclusions Immobilization of anti-CD34 antibody on SES enhances endothelialization and may potentially be an effective therapeutic alternative to improve currently available drug-eluting stents.