title: Cholesterol-derivatized polyurethane: characterization and endothelial cell adhesion.
abstract: Endothelialization of synthetic surfaces has been challenging with limited success thus far. We investigated the hypothesis that covalent attachment of cholesterol to polyurethane via the urethane nitrogen groups would create a high-affinity surface for attachment and adhesion of endothelial cells. Cholesterol was covalently bound to the polyether polyurethane, Tecothane, by first derivatizing the polyurethane nitrogen groups with bromoalkyl side chains, followed by reacting mercapto-cholesterol to the bromoalkyl sites. Cholesterol-modified polyurethane demonstrated a qualitatively smoother surface per atomic force microscopy than nonmodified and increased surface energy (contact angle measurements) compared with unmodified polyurethane. Cell attachment assays showed a significantly greater number of attached bovine arterial endothelial cells (p = 0.0003) after 45 min of seeding on cholesterol-modified polyurethane versus unmodified polyurethane. Bovine arterial endothelial cells cultivated on cholesterol-modified Tecothane showed significantly greater levels of cell retention compared with unmodified Tecothane when exposed to arterial level shear stress for 2 h (25 dynes/cm2) with 90.0 +/- 6.23% cells remaining adherent compared with unmodified polyurethane, 41.4 +/- 11.7%, p = 0.0070. Furthermore, ovine endothelial precursors, obtained as blood outgrowth endothelial cells, were seeded on cholesterol-modified polyurethane and exposed to 25 dynes/cm2 shear conditions for 2 h, with the retention of 90.30 +/- 3.25% of seeded cells versus unmodified polyurethane, which retained only 4.56 +/- 0.85% (p < 0.001). It is concluded that covalently linking cholesterol to polyurethane results in improved material properties that permit increased endothelial cell retention compared with unmodified polyurethane.
authors.affiliation: Division of Cardiology, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania 19104-4318, USA.
authors.forename: Stanley J
authors.initials: SJ
authors.lastname: Stachelek
authors.forename: Ivan
authors.initials: I
authors.lastname: Alferiev
authors.forename: Hoon
authors.initials: H
authors.lastname: Choi
authors.forename: Allyson
authors.initials: A
authors.lastname: Kronsteiner
authors.forename: Pimporn
authors.initials: P
authors.lastname: Uttayarat
authors.forename: Keith J
authors.initials: KJ
authors.lastname: Gooch
authors.forename: Russell J
authors.initials: RJ
authors.lastname: Composto
authors.forename: I-Wei
authors.initials: IW
authors.lastname: Chen
authors.forename: Robert P
authors.initials: RP
authors.lastname: Hebbel
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Levy
mesh_terms: D000818:Animals; D002417:Cattle; D002448:Cell Adhesion; D049109:Cell Proliferation / Q000187:drug effects; D002478:Cells, Cultured; D002784:Cholesterol / Q000737:chemistry*; D042783:Endothelial Cells / Q000166:cytology*; D007700:Kinetics; D009682:Magnetic Resonance Spectroscopy; D018625:Microscopy, Atomic Force; D015394:Molecular Structure; D011140:Polyurethanes / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared; D013314:Stress, Mechanical; D013696:Temperature
chemical_list: D011140:Polyurethanes; D002784:Cholesterol