title: Chemisorbed poly(propylene sulphide)-based copolymers resist biomolecular interactions.
abstract: Alkanethiolates have been widely used as chemisorbates to modify gold surfaces, in spite of their relatively poor oxidative stability. We introduce gold-chemisorbing block copolymers bearing an anchoring block of poly(propylene sulphide) (PPS), selected in the expectation of greater stability. These materials offer a more robust approach to surface modification of gold. As an example, a triblock copolymer with poly(ethylene glycol) (PEG) was selected, with the goal of minimizing biological adsorption and adhesion. The copolymer PEG17-bl-PPS25-bl-PEG9 chemisorbed to form a dense monolayer of 226 +/- 26 ng cm(-2), approximately 2.2 nm thick. The copolymeric adlayer was much more stable to oxidation than commonly used alkanethiolates. Its presence greatly reduced protein adsorption (>95%), even after exposure to whole blood serum (>55 mg x ml(-1)), as well as cell adhesion over long culture durations (>97%). PPS-containing copolymers are an attractive alternative to alkanethiolates, and PEG-bl-PPS-bl-PEG presents a powerful example for use in biodiagnostic and bioanalytical devices.
authors.affiliation: Institute for Biomedical Engineering and Department of Materials Science, University and ETH Zurich, CH-8044 Zurich, Switzerland.
authors.forename: J P
authors.initials: JP
authors.lastname: Bearinger
authors.forename: S
authors.initials: S
authors.lastname: Terrettaz
authors.forename: R
authors.initials: R
authors.lastname: Michel
authors.forename: N
authors.initials: N
authors.lastname: Tirelli
authors.forename: H
authors.initials: H
authors.lastname: Vogel
authors.forename: M
authors.initials: M
authors.lastname: Textor
authors.forename: J A
authors.initials: JA
authors.lastname: Hubbell
mesh_terms: D000327:Adsorption; D000818:Animals; D001773:Blood Cells / Q000502:physiology; D002448:Cell Adhesion / Q000502:physiology; D002478:Cells, Cultured; D020099:Coated Materials, Biocompatible / Q000737:chemistry*; D005347:Fibroblasts / Q000502:physiology*; D006046:Gold / Q000737:chemistry*; D006801:Humans; D008297:Male; D008422:Materials Testing / Q000379:methods; D008567:Membranes, Artificial; D011092:Polyethylene Glycols / Q000737:chemistry*; D011108:Polymers / Q000737:chemistry; D051381:Rats; D012709:Serum Albumin / Q000737:chemistry*; D012879:Skin Physiological Phenomena; D013440:Sulfides / Q000737:chemistry*
chemical_list: D020099:Coated Materials, Biocompatible; D008567:Membranes, Artificial; D011108:Polymers; D012709:Serum Albumin; D013440:Sulfides; C090687:propylene sulfide; D011092:Polyethylene Glycols; D006046:Gold