Structure and hemocompatibility of nanocrystalline titanium nitride produced under glow-discharge conditions

• Published in: Applied surface science 2018-04, Vol.436, p.382-390
• Main Authors: Sowińska, Agnieszka, Czarnowska, Elżbieta, Tarnowski, Michał, Witkowska, Justyna, Wierzchoń, Tadeusz
• Format: Article
• Language: English
• Subjects: Glow-discharge nitriding; Hemocompatiblity; Nanotopography; Nitrided surface layer
• ISSN: 0169-4332; 1873-5584
• DOI: 10.1016/j.apsusc.2017.12.028

The glow-discharge nitriding process produces TiN+Ti2N+αTi(N) diffusion layers. First study on the effect of plasma and cathode regions on TiN layers properties. The nitrided layers differ in terms of thickness, roughness and surface free energy. TiN layer produced at plasma region has better hemocompatibility. Significant efforts are being made towards developing novel antithrombotic materials. The purpose of the presented study was to characterize two variants of nitrided surface layers produced on alloy Ti-6Al-4V in different areas of low-temperature plasma – at the plasma potential (TiNp) or at the cathode potential (TiNc). The layers were characterized in terms of their microstructure, surface topography and wettability, and platelet response to the environment of different pH. The produced layers were of the TiN+Ti2N+αTiN-type, but the layer produced at the plasma potential was thinner, smoother and had lower surface free energy compared with that produced at the cathode potential. Biological evaluation demonstrated more fibrinogen buildup, less platelet adhesion and aggregation, and fewer strongly activated platelets on the TiNp surface compared with those parameters on the TiNc surface and on the titanium alloy in its initial state. Interestingly, both surface types were significantly resistant to fibrinogen adsorption and platelet adhesion in the environment of lower pH. In conclusion, the nitrided surface layer produced at the plasma potential is a promising material and this basic information is critical for further development of hemocompatible materials.