Multi-layer haemocompatible diamond-like carbon coatings obtained by combined radio frequency plasma enhanced chemical vapor deposition and magnetron sputtering.
Radio-frequency Plasma Enhanced Chemical Vapour Deposition (in different methane dilutions) was used to synthesize adherent and haemocompatible diamond-like carbon (DLC) films on medical grade titanium substrates. The improvement of the adherence has been achieved by interposing a functional buffer layer with graded composition TixTiC1-x (x = 0-1) synthesized by magnetron co-sputtering. Bonding strength values of up to ~67 MPa have been measured by pull-out tests. Films with different sp(3)/sp(2) ratio have been obtained by changing the methane concentration in the deposition chamber. Raman spectroscopy, X-ray photoelectron spectroscopy and X-ray diffraction were employed for the physical-chemical characterization of the samples. The highest concentration of sp(3)-C (~87 %), corresponding to a lower DLC surface energy (28.7 mJ/m(2) ), was deposited in a pure methane atmosphere. The biological response of the DLC films was assayed by a state-of-the-art biological analysis method (surface enhanced laser desorption/ionization-time of flight mass spectroscopy), in conjunction with other dedicated testing techniques: Western blot and partial thromboplastin time. The data support a cause-effect relationship between sp(3)-C content, surface energy and coagulation time, as well as between platelet-surface adherence properties and protein adsorption profiles.
Army Centre for Medical Research, 020012, Bucharest, Romania.
A C
AC
Popa
G E
GE
Stan
M A
MA
Husanu
I
I
Pasuk
I D
ID
Popescu
A C
AC
Popescu
I N
IN
Mihailescu
D000327:Adsorption; D002244:Carbon / Q000737:chemistry*; D020099:Coated Materials, Biocompatible / Q000737:chemistry*; D018130:Diamond / Q000737:chemistry*; D006801:Humans; D013058:Mass Spectrometry; D008422:Materials Testing; D008697:Methane / Q000737:chemistry; D010314:Partial Thromboplastin Time; D056951:Photoelectron Spectroscopy; D010973:Platelet Adhesiveness; D013059:Spectrum Analysis, Raman; D013499:Surface Properties; D014025:Titanium / Q000737:chemistry; D014961:X-Ray Diffraction
D020099:Coated Materials, Biocompatible; D002244:Carbon; D018130:Diamond; D014025:Titanium; D008697:Methane