Formation of Hydroxyapatite on Ti-Coated Ti-Zr-Cu-Pd Bulk Metallic Glass

Abstract

In this research, Ti coating was conducted on Ti 40 Zr 10 Cu 36 Pd 14 bulk metallic glass (BMG) in order to increase the formation rate of hydroxyapatite layer. The formation behavior of bone-like hydroxyapatite on Ti-coated and uncoated Ti 40 Zr 10 Cu 36 Pd 14 bulk metallic glasses (BMGs) was studied. The surface morphology of Ti-coated and uncoated Ti 40 Zr 10 Cu 36 Pd 14 BMG was investigated by scanning electron microscopy and energy dispersive X-ray spectroscopy. The results revealed that the alkali pretreatment in 5 M NaOH solution at 60 C for 24 h had a beneficial effect on the formation of porous sodium titanate on Ti-coated Ti 40 Zr 10 Cu 36 Pd 14 BMG. A bone-like hydroxyapatite layer was able to form on the alkali-treated Ti-coated Ti 40 Zr 10 Cu 36 Pd 14 BMG after a short-time immersion in simulated body fluid (SBF). On the contrary, hydroxyapatite formation was not observed on the uncoated Ti 40 Zr 10 Cu 36 Pd 14 BMG after the same chemical treatments.

Bioactivity of a Ni-Free Ti-Based Metallic Glass

“…The previous work 6) revealed that simple alkali soaking at 60 C even for one day, can't induce the formation of apatite on the surface of Ti-based BMGs due to high concentration of Cu, Pd and Zr elements. The effect of the hydrothermalelectrochemical treatment can increase the surface roughness as well as the Ti concentration on the outer layer of metallic glass.…”

“…1) Recently, the developments of Ni-free Ti-Zr-Cu-Pd and TiZr-Cu-Pd-Sn BMGs with high glass-forming ability, high strength and good corrosion resistance and their composites make it possible to create novel Ti-based BMG implants with superior mechanical properties and excellent bioactivity. [2][3][4][5] On the other hand, the bioactivity on Ti-based BMGs in previous works, 6) is not good enough to be applied as implant materials. Hydroxyapatite can't be formed on the surface of Ti-based BMGs after simple immersion in 5 M NaOH solution followed by immersion in SBF.…”

“…Hydroxyapatite can't be formed on the surface of Ti-based BMGs after simple immersion in 5 M NaOH solution followed by immersion in SBF. 6) Some apatite particles were deposited only physically and covered on the surface of Ti-based BMGs with hydrothermal hot-pressing treatment. 7) The formation and growth rate of bone-like apatite on metallic implants in SBF before implant are usually regarded as a criterion in evaluating bioactivity of metallic implants.…”

Recent Progress in Ti-Based Metallic Glasses for Application as Biomaterials

“…A bone-like hydroxyapatite layer was formed on the alkali-treated Ti-coated Ti 40 Zr 10 Cu 36 Pd 14 BMGs after a short-time immersion in simulated body fluid (SBF). 102) After the samples were immersed only for one day, a few white nuclei were observed, demonstrating that the initiation of nucleation was fulfilled within a short immersion time. With an increase of the immersion time, the particles gradually proliferated and spread all over the surface during a 15-day immersion.…”

“…In order to improve apatite-forming ability of Ti-based BMGs, some methods such as Ti coating on Ti-based BMG substrates by physical vapor deposition (PVD) technique, 102,111) and a two-step method consisting of hydrothermal-electrochemical treatment followed by pre-calcification treatment, 112) have been developed. The Ti 40 Zr 10 Cu 36 Pd 14 BMG samples were coated by a PVD method using magnetron-sputtering of pure Ti metal cathode in a nitrogen protective atmosphere at 473 K, then were treated in 5 M NaOH solution at 333 K for 24 h, which was demonstrated that sodium titanate layer with a porous structure was formed on the surface of the Ti-coated Ti 40 Zr 10 Cu 36 Pd 14 BMGs.…”