title: Plasma-induced nanopillars on bare metal coronary stent surface for enhanced endothelialization.
abstract: An increased risk of late stent thrombosis associated with polymer carriers on the surface of drug-eluting stents remains one of the challenges in cardiovascular stent technology, which has instigated a renewed interest in the polymer-less, bare metal stent approach. As thrombus formation is most likely augmented by the lack of endothelial cell coverage at the exposed stented site, an improved stent surface that enhances cell coverage is essential for viable polymer-less all metal stents. We demonstrate superior endothelial cell growth, more continuous monolayer formation and overall improved endothelialization with nanopillar arrays created via radio frequency plasma surface texturing on our all metallic stent surface of MP35N stent alloy. It is shown that the nanotextured surface significantly up-regulates primary bovine aortic endothelial cell (BAEC) functionality when compared with unprocessed, smooth MP35N surfaces without a nanopillar topography. The desirable presence of transmembrane tight junctions and highly organized monolayer formation was induced by the presence of the nanopillar surface texture. The nanopillar structure also produced a reduced level of oxidative stress in the BAECs. These findings may contribute to new nanotechnology-based surface design concepts for bare metal stents producing advanced cardiovascular implants which mitigate late stent thrombosis.
authors.affiliation: Materials Science and Engineering, University of California San Diego, La Jolla, CA 92093, USA.
authors.forename: Mariana C
authors.initials: MC
authors.lastname: Loya
authors.forename: Karla S
authors.initials: KS
authors.lastname: Brammer
authors.forename: Chulmin
authors.initials: C
authors.lastname: Choi
authors.forename: Li-Han
authors.initials: LH
authors.lastname: Chen
authors.forename: Sungho
authors.initials: S
authors.lastname: Jin
mesh_terms: D000199:Actins / Q000378:metabolism; D000497:Alloys / Q000737:chemistry; D000818:Animals; D002417:Cattle; D002448:Cell Adhesion / Q000187:drug effects; D002452:Cell Count; D003331:Coronary Vessels / Q000187:drug effects / Q000473:pathology*; D042783:Endothelial Cells / Q000166:cytology / Q000187:drug effects / Q000378:metabolism / Q000648:ultrastructure; D004730:Endothelium, Vascular / Q000187:drug effects* / Q000473:pathology*; D005452:Fluoresceins / Q000378:metabolism; D005455:Fluorescent Antibody Technique; D008670:Metals / Q000737:chemistry*; D018625:Microscopy, Atomic Force; D008855:Microscopy, Electron, Scanning; D053758:Nanoparticles / Q000737:chemistry*; D018384:Oxidative Stress / Q000187:drug effects; D058626:Plasma Gases / Q000494:pharmacology*; D011846:Radio Waves; D013052:Spectrometry, X-Ray Emission; D015607:Stents; D013499:Surface Properties / Q000187:drug effects
chemical_list: D000199:Actins; D000497:Alloys; D005452:Fluoresceins; D008670:Metals; D058626:Plasma Gases; C035402:MP35N alloy; C029569:diacetyldichlorofluorescein