Abstract 13759: Nitrogen Rich Plasma Activated Coatings for Enhancement of Endovascular Stent Biocompatibility
Introduction: Stent thrombosis and restenosis are clinical manifestations of suboptimal biocompatibility. A novel coating platform that simultaneously promotes endothelialization and inhibits thrombosis may circumvent deficiencies in stent biocompatibility.
Objective: A plasma activated coating (PAC) for surface modification of metallic alloys using plasma enhanced chemical vapor deposition was developed. To enhance biocompatibility, nitrogen gas doping during deposition was deployed to produce nitrogenized PAC variants.
Methods and Results: PAC with nitrogen concentrations of 3% (PAC3), 14% (PAC14) and 27% (PAC27) was created. PAC27 was the most hydrophilic (water contact angle 55.2±1.7°) and enriched with polar surface chemical groups. Thrombogenicity studies revealed an inverse relationship between nitrogen content and thrombus formation in static blood assays (316L steel (SS): 210.4±16.8, PAC3: 74.4±43.3, PAC14: 58.5±38.6, PAC27: 4.5 ± 3.28 mg, P<0.05, (Fig 1A and B)) and in Chandler loop assays (SS: 36.3±3.5, PAC3: 33.5±1.9, PAC14: 15.4±3.4, PAC27: 5.3±3.4 mg, P<0.05). Platelet activation in the Chandler loop measured by P-selectin levels was lower for PAC27 than SS, 12.3±1.4 vs. 17.4±1.7 ng/ml, P<0.05). High nitrogen PAC also enhanced human coronary artery endothelial cell (HCAEC) adhesion (38.7±4.7% (SS), 45.2±6.8% (PAC3), 53.6±6.6% (PAC14), 70.4±2.7% (PAC27) attachment, p<0.05) (Fig 1C). Furthermore, HCAEC proliferation on PAC27 was 23.9±1.3% higher than SS, p<0.001. Robust adhesion of PAC27 coated on SS stents was seen on scanning electron microscope.
Conclusions: A nitrogen rich PAC has been developed for surface modification of stent related metal alloys. PAC deposition strikingly reduces thrombogenicity and enhanced HCAEC adhesion & proliferation in a nitrogen dependent manner. This high scalable technology, compatible with contemporary stent platforms, has potential to enhance the biocompatibility of endovascular stents.
Author Disclosures: Y. Yu: None. A. Kondyurin: None. S.G. Wise: None. D.S. Celermajer: None. M.M. Bilek: None. M.K. Ng: None.
- © 2014 by American Heart Association, Inc.