title: Reduction of late in-stent stenosis in a porcine coronary artery model by cobalt chromium stents with a nanocoat of polyphosphazene (Polyzene-F).
abstract: The purpose of this study was to investigate the potential of nanoscale coating with the highly biocompatible polymer Polyzene-F (PZF), in combination with cobalt chromium and stainless steel stents, to reduce in-stent stenosis, thrombogenicity, and vessel wall injury and inflammation. One bare cobalt chromium, PZF-nanocoated stainless steel or PZF-nanocoated cobalt chromium stent was implanted in right coronary artery of 30 mini-pigs (4- or 12-week follow-up). Primary study end points were in-stent stenosis and thrombogenicity. Secondary study end points were vessel wall injury and inflammation as evaluated by microscopy and a new immunoreactivity score applying C-reactive protein (CRP), tumor-necrosis factor alpha (TNFalpha), and TGFbeta. At 12 weeks, angiography showed a significantly lower average loss in lumen diameter (2.1% +/- 3.05%) in PZF-nanocoated cobalt chromium stents compared with stents in the other groups (9.73% +/- 4.93% for bare cobalt chromium stents and 9.71% +/- 7% for PZF-nanocoated stainless steel stents; p = 0.04), which was confirmed at microscopy (neointima 40.7 +/- 16 lm in PZF-nanocoated cobalt chromium stents, 74.7 +/- 57.6 lm in bare cobalt chromium stents, and 141.5 +/- 109 lm in PZF-nanocoated stainless steel stents; p = 0.04). Injury and inflammation scores were low in all stents and were without significant differences. PZF-nanocoated cobalt chromium stents provided the highest efficacy in reducing in-stent stenosis at long-term follow-up. The PZF nanocoat proved to be biocompatible with respect to thromboresistance and inflammation. Our data suggest that its combination with cobalt chromium stents might provide an interesting passive stent platform.
authors.affiliation: Department of Radiology, University of Heidelberg, INF 110, 69120 Heidelberg, Germany.
authors.forename: Ulrike
authors.initials: U
authors.lastname: Stampfl
authors.forename: Christof-Matthias
authors.initials: CM
authors.lastname: Sommer
authors.forename: Heidi
authors.initials: H
authors.lastname: Thierjung
authors.forename: Sibylle
authors.initials: S
authors.lastname: Stampfl
authors.forename: Ruben
authors.initials: R
authors.lastname: Lopez-Benitez
authors.forename: Boris
authors.initials: B
authors.lastname: Radeleff
authors.forename: Irina
authors.initials: I
authors.lastname: Berger
authors.forename: Goetz M
authors.initials: GM
authors.lastname: Richter
mesh_terms: D000818:Animals; D002097:C-Reactive Protein / Q000378:metabolism; D002857:Chromium; D020099:Coated Materials, Biocompatible; D003035:Cobalt; D017023:Coronary Angiography; D023903:Coronary Restenosis / Q000517:prevention & control*; D005260:Female; D008233:Lymphotoxin-alpha / Q000378:metabolism; D009943:Organophosphorus Compounds; D011108:Polymers; D018709:Statistics, Nonparametric; D015607:Stents; D013552:Swine; D013556:Swine, Miniature; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism
chemical_list: D020099:Coated Materials, Biocompatible; D008233:Lymphotoxin-alpha; D009943:Organophosphorus Compounds; D011108:Polymers; D014409:Tumor Necrosis Factor-alpha; C108974:poly(phosphazene); D002857:Chromium; D003035:Cobalt; D002097:C-Reactive Protein