Polymer stent coating for prevention of neointimal hyperplasia.
OBJECTIVE
Restenosis has been the principal limitation of bare metal stents. Based upon the presumption that platelet and inflammatory cell recruitment initiate neointimal proliferation, we explored a novel polymer coating that reduces cell-stent interactions. The purpose of the present study was to investigate the effect of poly(L-lysine)-graft-poly(ethyleneglycol) (PLL-g-PEG) adsorbed to stent surfaces to reduce neointimal hyperplasia in the porcine restenosis model.


RESULTS
Seven animals were instrumented each with 2 stainless steel stents (15 mm length, 2.5-3.5 mm diameter), randomly implanted in 1 major epicardial coronary artery. One stent was dip-coated with PLL-g-PEG, whereas the other stent served as the uncoated control stent. All animals were sacrificed after 6 weeks for histological examination. Neointimal hyperplasia was significantly less (-51%) in the PLL-g-PEG-coated stents (1.15 +/- 0.59 mm2) than in the uncoated control stents (2.33 +/- 1.01 mm2; p < 0.001). Conversely, lumen size was larger in the PLL-g-PEG-coated stents (2.91 +/- 1.17 mm2) than in the uncoated stents (2.04 +/- 0.64 mm2; p < 0.001). High magnification histomorphologic examination revealed no signs of inflammation or thrombus formation in either stent group.


CONCLUSIONS
Polymeric steric stabilization of stents with PLL-g-PEG significantly reduces neointimal hyperplasia in the porcine restenosis model. Reduction of cell-stent interactions mediated by PLL-g-PEG appear to improve biocompatibility of stainless steel stents without evidence of adverse inflammatory or prothrombotic effects.
Billinger
Michael
M
Department of Cardiology, University Hospital Bern, Switzerland.
Buddeberg
Felix
F
Hubbell
Jeffrey A
JA
Elbert
Donald L
DL
Schaffner
Thomas
T
Mettler
Daniel
D
Windecker
Stephan
S
Meier
Bernhard
B
Hess
Otto M
OM
D015906:Angioplasty, Balloon, Coronary / Q000295:instrumentation / Q000379:methods; D000818:Animals; D049109:Cell Proliferation; D020099:Coated Materials, Biocompatible / Q000627:therapeutic use*; D023903:Coronary Restenosis / Q000209:etiology / Q000517:prevention & control / Q000628:therapy*; D003328:Coronary Thrombosis / Q000517:prevention & control; D004195:Disease Models, Animal; D005260:Female; D006965:Hyperplasia / Q000150:complications / Q000209:etiology / Q000517:prevention & control; D008297:Male; D008422:Materials Testing; D011092:Polyethylene Glycols / Q000627:therapeutic use*; D011107:Polylysine / Q000031:analogs & derivatives* / Q000627:therapeutic use; D015607:Stents / Q000009:adverse effects; D013552:Swine; D017539:Tunica Intima / Q000473:pathology*
D020099:Coated Materials, Biocompatible; C443714:polylysine-graft-(poly(ethylene glycol)); D011107:Polylysine; D011092:Polyethylene Glycols