Effect of different Ti–6Al–4V surface treatments on osteoblasts behaviour

Abstract

The purpose of the present work was to examine the effect of different Ti-6Al-4V surface treatments on osteoblasts behaviour. Previous work in this laboratory has demonstrated that an ageing treatment reduces metal ion release from this alloy compared to standard passivation procedures. In this study, human osteosarcoma MG-63 were used in short-term in vitro tests to assay for cell viability and cell proliferation at 12, 24 and 72 h while SaOS-2 were used in long-term in vitro tests to assay for osteonectin, osteopontin, osteocalcin gene expression, total protein amount (TP), alkaline phosphatase activity (ALP) and fibronectin production (FN) for 1-4 weeks. Epifluorescence microscopy was used to observe SaOS-2 cell morphology. After 24 h, there was no difference in MG-63 cell viability/proliferation or in SaOS-2 cell morphology between the different surface treatments. For the longterm tests, the aged Ti-6Al-4V induced significantly higher cell proliferation than the control Ti-6Al-4V at 72 h. At week 1, no difference in the osteonectin, osteopontin, and osteocalcin gene expression was found between samples. The peak of ALP activity appeared earlier at week 2 for the control surface compared with the passivated and aged surfaces. The early increase in ALP activity for the control sample could be a compensatory effect of decreased osteoblasts proliferation. There was no difference in the expression of FN for the different surface treatments. Our present results showed that the different surface treatments, which induced different metal ion release kinetics and surface properties, influenced the cell proliferation and ALP activity of osteoblast cells. Aluminium ions release kinetics as well as presence of vanadium ions may play a major role in influencing the osteoblasts behaviour in the present study. r

Large-scale gene expression analysis of osteoblasts cultured on three different Ti–6Al–4V surface treatments

“…By extrapolating the time course of gene expression in the Pathway 1, there should be a decrease of cell proliferation for the samples C and P compared to A. This is what we found in a previous study [14], however using a different cell line rendering direct comparison delicate. This delay in the gene expression time course could be due to the decrease of aluminium ions being released by the surface treatment A [12] as it has been suggested that aluminium may alter the timing/regulation of the proliferation/differentiation transition point [30].…”

“…The hip stems were cut into discs of 10 mm diameter and of 1 mm thickness. The samples were polished following a previously described procedure [14]. The samples were then cleaned in 1% Triton solution for 1 h and rinsed in deionized distilled water.…”

“…We developed a third treatment that we called aged treatment (A), which consisted of the passivated treatment followed by ageing in boiling deionized distilled water for 10 h [11,12]. The samples were then sterilized and tested for endotoxin contamination [14].…”

Development of copper-enriched porous coatings on ternary Ti-Nb-Zr alloy by plasma electrolytic oxidation

“…Some previous papers described the porous and bactericidal coatings on alloys, such as Ti6Al4V [38] and Ti-Nb-Zr-Sn [44] obtained by PEO known also as microarc oxidation (MAO). In those articles, the focal point of analysis was dedicated to the presence of elements displaying a detrimental action in the human body, such as vanadium, aluminum [38, 56,57], and tin [38,58].…”

Anodic oxidation of the Ti–13Nb–13Zr alloy

“…Al has well-documented toxic effects in the serum or urine of the patients who have total hip replacements composed of the titanium alloy [13,14]. In addition, aluminum has a causal relationship with the neurotoxicity and senile dementia of the Alzheimer type [15][16][17]. The increasingly stringent requirements of the long-term implants must be met, and the growing doubts regarding the cytotoxicity of the titanium alloys containing vanadium have triggered investigations on the vanadium-free titanium alloys.…”