Development of hydrophilic NbCuSi(N) &TiAlNb(N) coatings as a new strategy for medical implants modification

Herein we report the results of multi-element nitride and intermetallic coatings obtained by the arc-PVD method based on non-trivial elements combinations (Nb - 75.5, Si - 9.65, Cu - 14.85 at% and Ti - 81.8, Nb - 11.8, Al - 6.4 at%). Our experiments examine the development and evolution of biocompatible coatings for metal implants and medical devices. The elemental composition of the surface, microstructure, contact angle and biocompatibility of the coatings were studied. XRD results demonstrated that in the intermetallic TiAlNb samples, a multiphase state is formed between γ-TiAl, TiAl2, and α-Nb5Si3, since only a small part of Nb atoms occupy the same lattice sites as Ti atoms, which leads to the formation of a competing phase α-Nb5Si3. The NbCuSi coatings predominantly consist of Nbss with inclusions of silicon silicide. The human umbilical cord mesenchymal stem cells (MSC) were used for biocompatibility assessment using resazurin reduction assay and fluorescent DAPI staining. We show the high biocompatibility and ability to stimulate cell proliferation and distribution over the intermetallic coatings, especially when compared to nitrides ones. Although intermetallic coatings exhibit a higher surface contact angle due to uneven morphology, all samples exhibit hydrophilic properties, which favourably affect cell adhesion and proliferation.