scholarly journals On the Origin of Reduced Cytotoxicity of Germanium-Doped Diamond-Like Carbon: Role of Top Surface Composition and Bonding

Nanomaterials ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 567
Author(s):  
Josef Zemek ◽  
Petr Jiricek ◽  
Jana Houdkova ◽  
Martin Ledinsky ◽  
Miroslav Jelinek ◽  
...  

This work attempts to understand the behaviour of Ge-induced cytotoxicity of germanium-doped hydrogen-free diamond-like carbon (DLC) films recently thoroughly studied and published by Jelinek et al. At a low doping level, the films showed no cytotoxicity, while at a higher doping level, the films were found to exhibit medium to high cytotoxicity. We demonstrate, using surface-sensitive methods—two-angle X-ray-induced core-level photoelectron spectroscopy (ARXPS) and Low Energy Ion Scattering (LEIS) spectroscopy, that at a low doping level, the layers are capped by a carbon film which impedes the contact of Ge species with tissue. For higher Ge content in the DLC films, oxidized Ge species are located at the top surface of the layers, provoking cytotoxicity. The present results indicate no threshold for Ge concentration in cell culture substrate to avoid a severe toxic reaction.

1987 ◽  
Vol 2 (1) ◽  
pp. 117-131 ◽  
Author(s):  
Thomas J. Hook ◽  
Joseph A. Gardella ◽  
Lawrence Salvati

Results from x-ray photoelectron spectroscopy (XPS or ESCA), low-energy ion scattering spectrometry (LEIS or ISS); and Fourier transform infrared spectroscopy (FTIR) analyses are presented for unmodified and modified poly (methylmethacrylate) (PMMA) polymer films. Analysis of the unmodified PMMA polymers (isotactic, syndiotactic, and atactic) via ESCA, ISS, and FTIR, established the surface composition, bonding, and functionality before the modification was employed. An rf-plasma glow discharge created from an Ar/H2O gas mixture at different exposure times and power levels was used to treat the polymer surface. Subsequent ESCA, ISS, and FTIR analyses of these modified PMMA's show the effects of surface modification in terms of a model of structural differences, over a limited depth (50–100 Å). The composition and functionality changes of the resulting surfaces are discussed with respect to proposed mechanisms of the plasma reaction and differences in tacticity of the reactant. A two-step reaction mechanism involving reactive decarboxylation/reduction followed by H2O adsorption is proposed to understand the spectroscopic results.


2012 ◽  
Vol 2012 ◽  
pp. 1-11 ◽  
Author(s):  
Sajid U. Khan ◽  
Johan E. ten Elshof

Eu3+-doped LaPO4and Tb3+-doped CePO4luminescent nanoparticles embedded in hybrid organosilica were patterned by two soft lithographic techniques. The role of various parameters such as solution chemistry, thermal protocols, and modification of the mold-substrate surface energies related to pattern shape formation and adhesion to the substrates have been studied. The shrinkage of the oxide patterns and shape evolution during the process was also examined. The patterns were characterized with optical and photoluminescence (PL) microscopy, X-ray diffraction (XRD), and scanning electron microscopy (SEM). Compositional analyses were carried out with X-ray photoelectron spectroscopy (XPS), low-energy ion scattering (LEIS), and secondary ion mass spectroscopy (SIMS). The results indicated that the final patterns obtained with these two techniques for the same material have different shapes and adherence to the substrates.


1998 ◽  
Vol 412-413 ◽  
pp. 631-638 ◽  
Author(s):  
Irene Spolveri ◽  
Andrea Atrei ◽  
Brunetto Cortigiani ◽  
Ugo Bardi ◽  
Alessandro Santucci ◽  
...  

2000 ◽  
Vol 643 ◽  
Author(s):  
R. Bastasz ◽  
C. J. Jenks ◽  
T. A. Lograsso ◽  
A. R. Ross ◽  
P. A. Thiel ◽  
...  

AbstractEnergy-angle distributions of low-energy inert-gas ions scattered from surfaces provide information about surface composition and structure. We have measured energy spectra of He+ scattered from an Al71Pd20Mn9 quasicrystal, which was oriented perpendicular to the 5-fold axis, along various azimuthal directions. Strong scattering signals are seen from Al and Pd, but only a weak Mn signal is observed. From measurements made of He+ at an oblique angle of incidence scattered in the forward direction, we observe a 72° periodicity in the azimuthal dependence of the scattering signal intensity from Al surface atoms. The effect arises from shadowing effects involving neighboring surface atoms and provides direct evidence that Al surface atoms exist in a local environment with 5-fold symmetry. In addition, measuring the variation of the signal intensity with incidence angle provides information about neighboring atom distances, which compare favorably with a model of the quasicrystal surface derived from the bulk structure.


2014 ◽  
Vol 711 ◽  
pp. 250-254 ◽  
Author(s):  
Wufanbieke Baheti ◽  
Ming Xin Li ◽  
Fu Guo Wang ◽  
Jin Ge Song ◽  
Long Hua Xu ◽  
...  

The nitrogen-doped diamond-like carbon film was prepared on Ti6Al4V alloy by using plasma enhanced chemical vapor deposition (PECVD) technique,and its biocompatibility was studied.The surface morphology,chemical composition and contact angle were measured by scanning electron microscope (SEM),X-ray photoelectron spectroscopy(XPS),Raman Spectrometer and contact angle measuring device. Finally, the proliferation rate and cellular morphology of 3T3-E1 osteoblast cells on different sample surfaces were tested and Image J software was used to statistically analyze the count of the adhered cells. The results showed that cell adhesion and proliferation were significantly (P<0.05) increased on nitrogen-doped diamond-like carbon films , which illustrated that N doping improved the biocompatibility of DLC films. This finding has potential clinical application value to modify titanium alloy for new bone formation.


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