A novel polymer-free ciglitazone-coated vascular stent: in vivo and ex vivo analysis of stent endothelialization in a rabbit iliac artery model.

Aim: Peroxisome proliferator-activated receptor-gamma (PPARg) agonists have known pleiotropic cardiovascular effects with favourable properties in vascular remodeling, and specifically in suppression of vascular smooth muscle cell proliferation. A novel vascular stent coating using the PPARg ligand ciglitazone (CCS) was investigated regarding its effects on endothelialization after 7 and 28 days.
Methods: Microporous bare metal stents (BMS) were coated with ciglitazone by ultrasonic flux with a load of 255 μg ciglitazone/stent. SixteenNew Zealand white rabbits, fed a with high cholesterol diet, underwent stent implantation in both iliac arteries. Everolimus-eluting stents (EES) and BMS were comparators. Histology (CD 31 immunostaining, confocal and scanning electron microscopy, morphometry) was performed after 7 and 28 days and by OCT (optical coherence tomography) in vivo after 28 days.
Results: Microscopy showed comparable results with near complete endothelialization in CCS and BMS (%CD31 above stent struts after 7 days: 67.92±36.35 vs. 84.48±23.86; p = 0.55; endothel % above stent struts: 77.22±27.9 vs. 83.89±27.91; p = 0.78). EES were less endothelialized with minimal fibrin deposition, not found in BMS and CCS (% CD 31 above struts after 28 days, BMS: 100.0±0.0 vs. EES: 95.9±3.57 vs. CCS: 100.0±0.0; p = 0.0292). OCT revealed no uncovered struts in all stents after 28 days.
Conclusions: Polymer-free coating with ciglitazone, a PPARg agonist is feasible and stable over time. Our data prove unimpaired endothelial coverage of a ciglitazone-coated vascular stent system by histology and OCT. Thus, this PPARg agonist coating deserves further investigation to evaluate its potency on local neointimal suppression.
Competing Interests: Dr. Otto has speaking engagements with Daiichi Sankyo Europe GmbH MSD SHARP & DOHME GmbH, received travel grants from BAYER VITAL GmbH, BOSTON SCIENTIFIC and BBraun Melsungen, and has an advisory board engagement with Berlin Chemie GmbH. Dr. Goebel received travel grants and speakers honorary from Actelion. Dr. Poerner received research grants from Abbott Vascular, B Braun and Boston Scientific, has speaking engagements with Daiichi Sankyo Europe GmbH, MSD SHARP & DOHME GmbH, BAYER VITAL GmbH, BOEHRINGER INGELHEIM GmbH, PFIZER GmbH, NICOLAI Medizintechnik GmbH and BOSTON SCIENTIFIC & BIOTRONIK GmbH. Dr. Figulla is a member of the European Advisory Board from Boston Scientific. Dr. Virmani is a consultant for Abbott Vascular, Medtronic, 480 Biomedical, and W.L. Gore; has speaking engagements with Merck; receives honoraria from Abbott Vascular, Boston Scientific, C.R. Bard, Medtronic, Microport Medical, OrbusNeich Medical, 480 Biomedical, and Terumo Corporation. The other authors have nothing to disclose.