Novel β-Ti35Zr28Nb alloy scaffolds manufactured using selective laser melting for bone implant applications

Abstract

Titanium (Ti) based tissue engineering scaffolds can be used to repair damaged bone. However, successful orthopedic applications of these scaffolds rely on their ability to mimic the mechanical properties of trabecular bone. Selective laser melting (SLM) was used to manufacture scaffolds of a new β-Ti35Zr28Nb alloy for biomedical applications. Porosity values of the scaffolds were 83% for the FCCZ structure (face centered cubic unit cell with longitudinal struts) and 50% for the FBCCZ structure (face and body centered cubic unit cell with longitudinal struts). The scaffolds had an elastic modulus of ∼1 GPa and a plateau strength of 8-58 MPa, which fall within the values of trabecular bone (0.2-5 GPa for elastic modulus and 4-70 MPa for compressive strength). The SLM-manufactured β-Ti35Zr28Nb alloy showed good corrosion properties. MTS assay revealed that both the FCCZ and FBCCZ scaffolds had a cell viability similar to the control. SEM observation indicated that the osteoblast-like cells adhered, spread and grew healthily on the surface of both scaffolds after culture for 7, 14 and 28 d, demonstrating good biocompatibility. Overall, the SLM-manufactured Ti35Zr28Nb scaffolds possess promising potential as hard-tissue implant materials due to their appropriate mechanical properties, good corrosion behavior and biocompatibility. STATEMENT OF SIGNIFICANCE: Novel β Ti35Zr28Nb alloy scaffolds with FCCZ and FBCCZ structures were successfully fabricated by selective laser melting (SLM) for biomedical applications. The scaffolds showed values of elastic modulus of ∼1 GPa and plateau strength of 8-58 MPa, which fall within the ranges of the mechanical properties of trabecular bone. The SLM-manufactured β Ti35Zr28Nb alloy showed good corrosion properties. Both SLM-manufactured FCCZ and FBCCZ scaffolds exhibited good biocompatibility, with osteoblast-like cells attaching, growing, and spreading in a healthy way on their surfaces after culturing for different periods up to 28 d.

Keywords: Biocompatibility; Corrosion; Mechanical property; Selective laser melting; β-Titanium alloy.