3D printing of a titanium-tantalum Gyroid scaffold with superb elastic admissible strain, bioactivity and in-situ bone regeneration capability

• Published in: Additive manufacturing 2021-11, Vol.47, p.102223, Article 102223
• Main Authors: Zhao, Danlei, Liang, Hang, Han, Changjun, Li, Jingjing, Liu, Jie, Zhou, Kun, Yang, Cao, Wei, Qingsong
• Format: Article
• Language: English
• Subjects: 3D printing; Bioactivity; Elastic admissible strain; In-situ bone regeneration; Titanium-tantalum alloy
• ISSN: 2214-8604; 2214-7810
• DOI: 10.1016/j.addma.2021.102223

The simultaneous achievement of admirable mechanical compatibility and osteoinduction in metallic implants can avoid stress shielding and facilitate osseointegration and osteogenesis. Herein, we reported a titanium-tantalum (Ti-Ta) Gyroid scaffold in-situ fabricated with selective laser melting (SLM), a powder-bed-fusion three-dimensional (3D) printing process, enabling superb elastic admissible strain (EAS), bioactivity and in-situ bone regeneration capability. The printed scaffold with 90% porosity exhibited a good combination of low elastic modulus (1.8 GPa) and high compressive yield strength (55.5 MPa), resulting in a superb EAS (3.03%) that is suitable for the reconstruction of cancellous bone. The mechanisms of the high EAS were ascribed to the formation of β(Ti, Ta) solid solution, ultrafine β grains accompanying with nanocrystalline α' grains, and the existence of dislocations and stacking faults. Bone-like apatite was spontaneously induced on the surface of the printed Ti-Ta alloy due to the generation of self-passivating Ta2O5 film, indicating a good biomineralization ability. Compared to pure Ti, the printed Ti-Ta alloy exhibited enhanced expression of vinculin, earlier cell extension, increased nuclei density, better cell proliferation, and the up-regulated expression of osteogenesis genes. Animal studies further validated that the printed Ti-Ta scaffold was capable to reinforce bone integration and accelerate bone regeneration. These findings provided a promising strategy for treating bone defects through 3D printing of metallic scaffolds. The schematic diagram of bone has been adapted from Servier Medical Art under a Creative Commons Attribution 3.0 Unported License. [Display omitted] •A Ti-Ta Gyroid scaffold with superb mechanical and biological performance was developed by 3D printing.•High elastic admissible strain and bioactivity of the scaffold were achieved.•3D-printed Ti-Ta scaffold was able to reinforce bone integration and accelerate bone regeneration.•The mechanisms of high elastic admissible strain and in situ bone regeneration were elucidated.