title: Microstructure of Cu-Ag Uniform Nanoparticulate Films on Polyurethane 3D Catheters: Surface Properties.
abstract: The preparation, characterization, and antibacterial testing of Cu-Ag sputtered polyurethane (PU) catheters are addressed in this study. PU catheters with different atomic ratios Cu:Ag have been sputtered and led to different optical properties as followed by diffuse reflectance spectroscopy (DRS) and the surface redox properties were also different for different Cu-Ag ratios as observed by X-ray photoelectron spectroscopy (XPS). The surface atomic percentage concentration of the oxidized/reduced C-species originating from bacterial cultures before and after bacterial inactivation were determined on the Cu-Ag PU catheters. The crystallographic properties were determined by X-ray diffraction (XRD). The XRD-diffractogram showed the presence of Cu2O (111), Cu (200), CuO (020), and Ag (111) indicating that Cu nanoparticles present a more crystalline character compared to Ag nanoparticles. Increasing the percentage of Ag in the Cu-Ag films, bigger Ag-particle agglomerates were detected by scanning transmission electron microscopy (STEM) microanalysis confirming the results obtained by AFM. The bacterial inactivation kinetics of the sputtered Cu-Ag films on PU catheters was investigated in detail. Quasi-instantaneous bacterial inactivation kinetics was induced by the sputtered films on PU catheters after optimization of the Cu-Ag film thickness.
authors.affiliation: EPFL-SB-ISIC-GPAO, Ecole Polytechnique Fédérale de Lausanne , Station 6, CH-1015, Lausanne, Switzerland.
authors.forename: Sami
authors.initials: S
authors.lastname: Rtimi
authors.affiliation: EPFL-SB-IPMC-LPCM, Ecole Polytechnique Fédérale de Lausanne , CH-1015 Lausanne, Station 3, Switzerland.
authors.forename: Rosendo
authors.initials: R
authors.lastname: Sanjines
authors.affiliation: EPFL-SB-ISIC-GPAO, Ecole Polytechnique Fédérale de Lausanne , Station 6, CH-1015, Lausanne, Switzerland.
authors.forename: Cesar
authors.initials: C
authors.lastname: Pulgarin
authors.affiliation: EPFL-SB-ISIC-GPAO, Ecole Polytechnique Fédérale de Lausanne , Station 6, CH-1015, Lausanne, Switzerland.
authors.forename: John
authors.initials: J
authors.lastname: Kiwi
mesh_terms: D057785:Catheters; D003300:Copper / Q000737:chemistry* / Q000494:pharmacology; D004583:Electrons; D004926:Escherichia coli / Q000187:drug effects; D007700:Kinetics; D053768:Metal Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D050296:Microbial Viability / Q000187:drug effects; D018625:Microscopy, Atomic Force; D056951:Photoelectron Spectroscopy; D011140:Polyurethanes / Q000737:chemistry*; D012834:Silver / Q000737:chemistry* / Q000494:pharmacology; D013052:Spectrometry, X-Ray Emission; D013499:Surface Properties; D014961:X-Ray Diffraction
chemical_list: D011140:Polyurethanes; D012834:Silver; D003300:Copper
keywords: Cu−Ag sputtered PU catheters; STEM; XPS; bacterial inactivation kinetics; optical absorption; roughness; uniformity of Cu−Ag coatings