Porous Ti-10Mo alloy fabricated by powder metallurgy for promoting bone regeneration

Abstract

Porous Ti-10Mo alloys were fabricated by powder metallurgy using a space-holder method. The pore characteristics, microstructure, mechanical properties, in vitro biocompatibility, and in vivo osseointegration of the fabricated alloys were systematically investigated. The results show that with different weight ratios of the space-holder (NH 4 HCO 3 ) added, all of the porous Ti-10Mo alloys sintered at 1,300°C exhibited a typical Widmanstatten microstructure. The porosity and average pore size of the porous structures can be controlled in the range of 50.8%66.9% and 70.1381.4 μm, respectively. The Ti-10Mo alloy with 63.4% porosity exhibited the most suitable mechanical properties for implant applications with an elastic modulus of 2.9 GPa and a compressive yield strength of 127.5 MPa. In vitro, the alloyconditioned medium showed no deleterious effect on the cell proliferation. The cell viability in this medium was higher than that of the reference group, suggesting non-toxicity and good biological characteristics of the alloy specimens. In vivo, after eight weeks implantation, new bone tissue formed surrounding the alloy implants, and no noticeable inflammation was observed at the implantation site. The bone bonding strength of the porous Ti-10Mo alloy increased over time from 46.6 N at two weeks to 176.4 N at eight weeks. Suitable mechanical properties together with excellent biocompatibility in vitro and osteointegration in vivo make the porous Ti-10Mo fabricated by powder metallurgy an attractive orthopedic implant alloy.