title: Bonding and bio-properties of hybrid laser/magnetron Cr-enriched DLC layers.
abstract: Chromium-enriched diamond-like carbon (DLC) layers were prepared by a hybrid technology using a combination of pulsed laser deposition (PLD) and magnetron sputtering. XRD revealed no chromium peaks, indicating that the layers are mostly amorphous. Carbon (sp(2) and sp(3) bonds) and chromium bonds were determined by XPS from C 1s, O 1s, and Cr 2p photoelectron peaks. Depending on the deposition conditions, the concentration of Cr in DLC layers moved from zero to 10 at.% for as-received sample surfaces, and to about 31 at.% after mild sputter-cleaning by argon ion cluster beam. It should be noted that the most stable Cr(3+) bonding state is in Cr2O3 and Cr(OH)3, and that there is the toxic Cr(6+) state in CrO3. The surface content of hexavalent chromium in the Cr 2p3/2 spectra is rather low, but discernible. The population density of Saos-2 cells was the highest in samples containing higher concentrations of chromium 7.7 and 10 at.%. This means that higher concentrations of chromium supported the cell adhesion and proliferation. In addition, as revealed by a LIVE/DEAD viability/cytotoxicity kit, the cells on all Cr-containing samples maintained high viability (96 to 99%) on days 1 and 3 after seeding. However, this seemingly positive cell behavior could be associated with the risk of dedifferentiation and oncogenic transformation of cells.
authors.affiliation: Institute of Physics, Academy of Sciences of the Czech Republic, v.v.i, Na Slovance 2, 18221 Prague, Czech Republic; Czech Technical University in Prague, Faculty of Biomedical Engineering, nam. Sitna 3105, 27201 Kladno, Czech Republic. Electronic address: jelinek@fzu.cz.
authors.forename: Miroslav
authors.initials: M
authors.lastname: Jelinek
authors.affiliation: Institute of Physics, Academy of Sciences of the Czech Republic, v.v.i, Na Slovance 2, 18221 Prague, Czech Republic.
authors.forename: Josef
authors.initials: J
authors.lastname: Zemek
authors.affiliation: Institute of Physiology of the Czech Academy of Sciences of the Czech Republic, v.v.i., Videnska 1083, 14220 Prague 4, Czech Republic.
authors.forename: Marta
authors.initials: M
authors.lastname: Vandrovcová
authors.affiliation: Institute of Physiology of the Czech Academy of Sciences of the Czech Republic, v.v.i., Videnska 1083, 14220 Prague 4, Czech Republic.
authors.forename: Lucie
authors.initials: L
authors.lastname: Bačáková
authors.affiliation: Institute of Physics, Academy of Sciences of the Czech Republic, v.v.i, Na Slovance 2, 18221 Prague, Czech Republic; Czech Technical University in Prague, Faculty of Biomedical Engineering, nam. Sitna 3105, 27201 Kladno, Czech Republic.
authors.forename: Tomáš
authors.initials: T
authors.lastname: Kocourek
authors.affiliation: Institute of Physics, Academy of Sciences of the Czech Republic, v.v.i, Na Slovance 2, 18221 Prague, Czech Republic; Czech Technical University in Prague, Faculty of Biomedical Engineering, nam. Sitna 3105, 27201 Kladno, Czech Republic.
authors.forename: Jan
authors.initials: J
authors.lastname: Remsa
authors.affiliation: Institute of Physics, Academy of Sciences of the Czech Republic, v.v.i, Na Slovance 2, 18221 Prague, Czech Republic; Czech Technical University in Prague, Faculty of Biomedical Engineering, nam. Sitna 3105, 27201 Kladno, Czech Republic.
authors.forename: Petr
authors.initials: P
authors.lastname: Písařík
mesh_terms: D001672:Biocompatible Materials / Q000737:chemistry* / Q000633:toxicity; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D002857:Chromium / Q000737:chemistry*; D018130:Diamond / Q000737:chemistry*; D006801:Humans; D007834:Lasers
chemical_list: D001672:Biocompatible Materials; D002857:Chromium; D018130:Diamond
keywords: Cell adhesion; Cell proliferation; Chromium; DLC; Hexavalent chromium; Hybrid PLD; Trivalent chromium