title: Interface of covalently bonded phospholipids with a phosphorylcholine head: characterization, protein nonadsorption, and further functionalization.
abstract: Surface anchored poly(methylhydrosiloxane) (PMHS) thin films on oxidized silicon wafers or glass substrates were functionalized via the SiH hydrosilylation reaction with the internal double bonds of 1,2-dilinoleoyl-sn-glycero-3-phosphorylcholine (18:2 Cis). The surface was characterized by X-ray photoelectron spectroscopy, contact angle measurements, atomic force microscopy, and scanning electron microscopy. These studies showed that the PMHS top layer could be efficiently modified resulting in an interfacial high density of phospholipids. Grafted phospholipids made the initially hydrophobic surface (θ = 106°) very hydrophilic and repellent toward avidin, bovine serum albumin, bovine fibrinogen, lysozyme, and α-chymotrypsin adsorption in phosphate saline buffer pH 7.4. The surface may constitute a new background-stable support with increased biocompatibility. Further possibilities of functionalization on the surface remain available owing to the formation of interfacial SiOH groups by Karstedt-catalyzed side reactions of SiH groups with water. The presence of interfacial SiOH groups was shown by zeta potential measurements. The reactivity and surface density of SiOH groups were checked by fluorescence after reaction of a monoethoxy silane coupling agent bearing Alexa as fluorescent probe.
authors.affiliation: Institut Européen des Membranes, Université Montpellier 2 (ENSCM, UM2, CNRS), CC047, 2 Place Eugène Bataillon, F-34095 Montpellier Cedex 5, France.
authors.forename: Lynda
authors.initials: L
authors.lastname: Ferez
authors.forename: Thierry
authors.initials: T
authors.lastname: Thami
authors.forename: Edefia
authors.initials: E
authors.lastname: Akpalo
authors.forename: Valérie
authors.initials: V
authors.lastname: Flaud
authors.forename: Lara
authors.initials: L
authors.lastname: Tauk
authors.forename: Jean-Marc
authors.initials: JM
authors.lastname: Janot
authors.forename: Philippe
authors.initials: P
authors.lastname: Déjardin
mesh_terms: D000327:Adsorption; D000818:Animals; D002417:Cattle; D010743:Phospholipids / Q000737:chemistry*; D010767:Phosphorylcholine / Q000737:chemistry*; D011506:Proteins / Q000737:chemistry*; D012833:Siloxanes / Q000737:chemistry; D014867:Water / Q000737:chemistry
chemical_list: D010743:Phospholipids; D011506:Proteins; D012833:Siloxanes; C402373:poly(methylhydrosiloxane); D014867:Water; D010767:Phosphorylcholine