# Advanced Ti–Nb–Ta Alloys for Bone Implants with Improved Functionality

## TL;DR

This paper explores new titanium-niobium-tantalum alloys for bone implants, showing they have better mechanical and biological properties than traditional materials.

## Contribution

The study introduces Ti–xNb–6Ta alloys fabricated via laser powder bed fusion with tailored mechanical and biological performance for orthopedic implants.

## Key findings

- Open porous Ti–20Nb–6Ta specimens show significantly reduced elasticity (8.1 ± 1.0 GPa) compared to dense ones.
- Human osteoblasts on Ti–Nb–Ta specimens show improved osteogenesis and reduced inflammation compared to Ti–6Al–4V.
- Build orientation affects cell spreading, with 90° orientation promoting wider cell stretching.

## Abstract

The additive manufacturing of titanium–niobium–tantalum alloys with nominal chemical compositions Ti–xNb–6Ta (x = 20, 27, 35) by means of laser beam powder bed fusion is reported, and their potential as implant materials is elaborated by mechanical and biological characterization. The properties of dense specimens manufactured in different build orientations and of open porous Ti–20Nb–6Ta specimens are evaluated. Compression tests indicate that strength and elasticity are influenced by the chemical composition and build orientation. The minimum elasticity is always observed in the 90° orientation. It is lowest for Ti–20Nb–6Ta (43.2 ± 2.7 GPa) and can be further reduced to 8.1 ± 1.0 GPa for open porous specimens (p < 0.001). Furthermore, human osteoblasts are cultivated for 7 and 14 days on as-printed specimens and their biological response is compared to that of Ti–6Al–4V. Build orientation and cultivation time significantly affect the gene expression profile of osteogenic differentiation markers. Incomplete cell spreading is observed in specimens manufactured in 0° build orientation, whereas widely stretched cells are observed in 90° build orientation, i.e., parallel to the build direction. Compared to Ti–6Al–4V, Ti–Nb–Ta specimens promote improved osteogenesis and reduce the induction of inflammation. Accordingly, Ti–xNb–6Ta alloys have favorable mechanical and biological properties with great potential for application in orthopedic implants.