In Vitro Biocompatibility of Si Alloyed Multi-Principal Element Carbide Coatings

Abstract

In the current study, we have examined the possibility to improve the biocompatibility of the (TiZrNbTaHf)C through replacement of either Ti or Ta by Si. The coatings were deposited on Si and 316L stainless steel substrates by magnetron sputtering in an Ar+CH4 mixed atmosphere and were examined for elemental composition, chemical bonds, surface topography, surface electrical charge and biocompatible characteristics. The net surface charge was evaluated at nano and macroscopic scale by measuring the electrical potential and work function, respectively. The biocompatible tests comprised determination of cell viability and cell attachment to the coated surface. The deposited coatings had C/(metal+Si) ratios close to unity, while a mixture of metallic carbide, free-carbon and oxidized species formed on the film surface. The coatings’ surfaces were smooth and no influence of surface roughness on electrical charge or biocompatibility was found. The biocompatible characteristics correlated well with the electrical potential/work function, suggesting a significant role of surface charge in improving biocompatibility, particularly cell attachment to coating's surface. Replacement of either Ti or Ta by Si in the (TiZrNbTaHf)C coating led to an enhanced surface electrical charge, as well as to superior biocompatible properties, with best results for the (TiZrNbSiHf)C coating.

Synergistic Effect of Cold Plasma Treatment and RGD Peptide Coating on Cell Proliferation over Titanium Surfaces

“…RGD groups. Previous studies have correlated decreased surface potential with increased negative charge on the surface which could be considered as a sign of increased number of hydroxyl groups on the surface of titanium discs treated with CAP, coated with RGD and their combination [71]. Such findings show consistency with cellular adhesion results as shown in Fig.…”

High-entropy ceramics: Present status, challenges, and a look forward

“…5.12. Si-containing coatings can further improve cell attachment and viability, with (HfNbSiTiZr)C being the most biocompatible material until now [262].…”

Processing and Properties of High-Entropy Ultra-High Temperature Carbides

“…As well as the diborides, “multi-principle component carbides” based on 5 or more near-equiatomic transition metal elements have also been successfully fabricated in the form of coatings. (Ti-Zr-Nb-Ta-Hf)C (with either Ti or Ta exchanged for Si) have been fabricated as biocompatible coatings for metal implants 8 and (Ti-Zr-Hf-V-Nb-Ta)C coatings with improved tribological behaviour have also been produced 9 . The (Ti-Zr-Hf-V-Nb-Ta)C coating exhibited an elastic modulus of 337 GPa, similar to that of the monocarbides; yet an extremely high hardness of 43–48 GPa, which is markedly higher than any of the component monocarbides.…”