Ni ion release, osteoblast–material interactions, and hemocompatibility of hafnium‐implanted NiTi alloy

Abstract

Hafnium ion implantation was applied to NiTi alloy to suppress Ni ion release and enhance osteoblast-material interactions and hemocompatibility. The auger electron spectroscopy, x-ray photoelectron spectroscopy, and atomic force microscope results showed that a composite TiO(2)/HfO(2) nanofilm with increased surface roughness was formed on the surface of NiTi, and Ni concentration was reduced in the superficial surface layer. Potentiodynamic polarization tests displayed that 4 mA NiTi sample possessed the highest E(br) - E(corr), 470 mV higher than that of untreated NiTi, suggesting a significant improvement on pitting corrosion resistance. Inductively coupled plasma mass spectrometry tests during 60 days immersion demonstrated that Ni ion release rate was remarkably decreased, for example, a reduction of 67% in the first day. The water contact angle increased and surface energy decreased after Hf implantation. Cell culture and methyl-thiazol-tetrazolium indicated that Hf-implanted NiTi expressed enhanced osteoblasts adhesion and proliferation, especially after 7 days culture. Hf implantation decreased fibrinogen adsorption, but had almost no effect on albumin adsorption. Platelets adhesion and activation were suppressed significantly (97% for 4 mA NiTi) and hemolysis rate was decreased by at least 57% after Hf implantation. Modified surface composition and morphology and decreased surface energy should be responsible for the improvement of cytocompatibility and hemocompatibility.

Nano-hardness, wear resistance and pseudoelasticity of hafnium implanted NiTi shape memory alloy

“…Composite HfO 2 /TiO 2 nano-film formed by Hf implantation (Zhao et al, 2011b), Hf implantation causes remarkable changes on the surface element distributions of NiTi alloy. It is seen from Fig.…”

“…Therefore, it is used as an ion source element for surface implantation on NiTi alloy to enhance its biocompatibility and corrosion and wear resistance. In our previous work, it was demonstrated that Hf implantation improved the corrosion resistance, suppressed Ni ion release and favored cell-materials interaction and hemocompatibility of NiTi alloy (Zhao et al, 2011b). However, the mechanical behavior of Hf implanted NiTi is not well understood.…”

A new design of a Nitinol ring-like wire for suturing in deep surgical field

“…e l s e v i e r . c o m / l o c a t e / m s e c modifications, such as coating, oxidation treatment, biochemistry method and ion implantation, cause the lowering of the amount of Ni ion release below the critical values that induce allergy and below the daily dietary intake level [9][10][11][12][13][14].…”

Corrosion Behavior of Fe/Zr Composite Coating on ZK60 Mg Alloy by Ion Implantation and Deposition

“…phases by MDI Jade 6.0, which correspond to the standard PDF #17-0385 and #17-0559, respectively. As a result of the non-ultra-high vacuum condition in the chamber [31], the energetic Zr ions reacted with the residual oxygen to form ZrO 0.35 incomplete oxide in the Zr II&D process and the subsequent incident Fe ions bombarded into the Zr-modified surface to produce Zr 6 Fe 3 O and α-Fe phases in the Fe II&D process. The Zr 6 Fe 3 O phase has a similar crystalline structure (cubic) with α-Fe phase, leading to the overlap of certain diffraction peaks.…”