Superior in vitro biocompatibility in NbTaTiVZr(O) high-entropy metallic glass coatings for biomedical applications

• Published in: Applied surface science 2022-09, Vol.596, p.153615, Article 153615
• Main Authors: Cemin, Felipe, Luís Artico, Leonardo, Piroli, Vanessa, Andrés Yunes, José, Alejandro Figueroa, Carlos, Alvarez, Fernando
• Format: Article
• Language: English
• Subjects: Biocompatibility; Biomaterials; Coatings; High-entropy alloys; Surface characterization; Thin films
• ISSN: 0169-4332; 1873-5584
• DOI: 10.1016/j.apsusc.2022.153615

[Display omitted] •The degree of disorder in high-entropy alloys (HEA) is extended, by developing amorphous coatings.•A novel NbTaTiVZr(O) high-entropy metallic glass (HEMG) is synthetized.•NbTaTiVZr(O) HEMG showed superior cytocompatibility than its HEA counterpart.•The HEMG exhibits stable surface chemical states, hydrophilicity, and enhanced corrosion resistance.•These findings may open up for innovative design strategies for biocoatings. This study combines the brand new concept of high-entropy designed materials with the superior properties of metallic glasses to obtain a NbTaTiVZr high-entropy metallic glass (HEMG) coating for biomedical applications. The amorphous structure is achieved by a room temperature magnetron sputtering deposition, whereas a bcc crystalline phase, typical of high-entropy alloys (HEA), is obtained at 400 °C. X-ray photoelectron spectroscopy showed that the oxygen concentration on the coatings surface is > 50% and significantly higher than in the bulk (∼ 5%). The NbTaTiVZr(O) HEMG surface is completely passivated, in contrast to the metallic + oxide outermost layer found for the HEA. Potentiodynamic polarization tests attested an improved corrosion resistance of the HEMG surface, which showed also increased hydrophilicity compared to the crystalline sample. In vitro biocompatibility investigations using both the hTERT-immortalized bone marrow mesenchymal cells and MG-63 osteosarcoma cells showed excellent viability (∼ 98% and ∼ 96%, respectively) and adhesion onto the HEMG coating after 96 h of incubation, indicating the integrity and biosafety of this surface. The cell viability and proliferation on the HEA and Ti (used as a benchmark) surfaces were much inferior. The enhanced surface protection and the superior biocompatibility makes the HEMG promising to be employed as a biocoating on orthopedic implants.