title: Biocompatible two-layer tantalum/titania-polymer hybrid coating.
abstract: Using a two-step procedure, radiopaque and biocompatible coatings were obtained, consisting of a tantalum layer deposited by sputtering technique and of an upper organic-inorganic hybrid layer synthesized via sol-gel. As shown by radiographic images, tantalum confers to plastic substrates good X-ray visibility, adjustable via control of deposition time, but its adhesion to the substrate is poor and manipulation easily damages the metal layer. Polymer-titania hybrid coatings, synthesized using poly-ε-caprolactone (PCL) or carboxy-terminated polydimethylsiloxane (PDMS) as organic precursors, were applied on the metal layer as biocompatible protective coatings. Biocompatibility is demonstrated by cytotoxicity tests conducted using vascular wall resident-mesenchymal stem cells (VW-MSCs). Both coatings show very good adhesion to the substrate, showing no sign of detachment upon large substrate deformations. Under such conditions, SEM observations show that the PCL-containing hybrid forms cracks, whereas the PDMS-based hybrid does not crack, suggesting possible applications of the latter material as a protective layer of sputtered tantalum radiopaque markers for flexible medical devices.
authors.affiliation: Dipartimento di Chimica "G. Ciamician", Università di Bologna and INSTM UdR Bologna, Via Selmi 2, 40126 Bologna, Italy.
authors.forename: Elisa
authors.initials: E
authors.lastname: Cortecchia
authors.forename: Annalisa
authors.initials: A
authors.lastname: Pacilli
authors.forename: Gianandrea
authors.initials: G
authors.lastname: Pasquinelli
authors.forename: Mariastella
authors.initials: M
authors.lastname: Scandola
mesh_terms: D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D020099:Coated Materials, Biocompatible / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*; D004129:Dimethylpolysiloxanes / Q000737:chemistry; D006801:Humans; D059630:Mesenchymal Stem Cells / Q000187:drug effects* / Q000378:metabolism; D011091:Polyesters / Q000737:chemistry; D011108:Polymers / Q000138:chemical synthesis* / Q000737:chemistry* / Q000494:pharmacology; D013499:Surface Properties; D013635:Tantalum / Q000737:chemistry*; D014025:Titanium / Q000737:chemistry*
chemical_list: D020099:Coated Materials, Biocompatible; D004129:Dimethylpolysiloxanes; D011091:Polyesters; D011108:Polymers; C009495:titanium dioxide; C016240:polycaprolactone; C013830:baysilon; D013635:Tantalum; D014025:Titanium