Abstract
An investigation was made of the adhesion, growth and differentiation of osteoblast-like MG-63 and Saos-2 cells on titanium (Ti) and niobium (Nb) supports and on TiNb alloy with surfaces oxidized at 165°C under hydrothermal conditions and at 600°C in a stream of air. The oxidation mode and the chemical composition of the samples tuned the morphology, topography and distribution of the charge on their surfaces, which enabled us to evaluate the importance of these material characteristics in the interaction of the cells with the sample surface. Numbers of adhered MG-63 and Saos-2 cells correlated with the number of positively-charged (related with the Nb2O5 phase) and negatively-charged sites (related with the TiO2 phase) on the alloy surface. Proliferation of these cells is correlated with the presence of positively-charged (i.e. basic) sites of the Nb2O5 alloy phase, while cell differentiation is correlated with negatively-charged (acidic) sites of the TiO2 alloy phase. The number of charged sites and adhered cells was substantially higher on the alloy sample oxidized at 600°C than on the hydrothermally treated sample at 165°C. The expression values of osteoblast differentiation markers (collagen type I and osteocalcin) were higher for cells grown on the Ti samples than for those grown on the TiNb samples. This was more particularly apparent in the samples treated at 165°C. No considerable immune activation of murine macrophage-like RAW 264.7 cells on the tested samples was found. The secretion of TNF-α by these cells into the cell culture media was much lower than for either cells grown in the presence of bacterial lipopolysaccharide, or untreated control samples. Thus, oxidized Ti and TiNb are both promising materials for bone implantation; TiNb for applications where bone cell proliferation is desirable, and Ti for induction of osteogenic cell differentiation.
Highlights
Titanium (Ti) - niobium (Nb) alloys have attracted much attention in recent times as promising materials for fabrication of bone implants because their non-toxicity, high corrosion resistance and beneficial mechanical properties [1,2,3], and because of their high biocompatibility, i.e. improved cell adhesion and proliferation, on their oxidized surfaces [4]
We have found that oxidized Ti, TiNb and Nb samples supported the attachment, spreading, proliferation and osteogenic differentiation of human osteoblast-like Saos-2 and MG-63 cells
The proliferation was most pronounced on the TiNb samples, while the Ti samples supported cell differentiation, manifested by a higher expression of collagen I and osteocalcin
Summary
Titanium (Ti) - niobium (Nb) alloys have attracted much attention in recent times as promising materials for fabrication of bone implants because their non-toxicity, high corrosion resistance and beneficial mechanical properties [1,2,3], and because of their high biocompatibility, i.e. improved cell adhesion and proliferation, on their oxidized surfaces [4]. As proteins can simultaneously carry charged sites at physiological pH, the surface characteristics related with the surface charge, chemical composition, topography and morphology of the solid sample, are essential for understanding the ECM molecules-surface interaction [4,5,6]. Two modes of heat-treatment were adopted: in deionized water (dei-H2O) under hydrothermal conditions at 165uC, and in a stream of air at 600uC The first of these two series of samples is referred to below as the Low Temperature (LT) series, while the second is referred to as the High Temperature (HT) series. These dramatically different treatment temperatures should produce oxidized alloy surfaces with substantially different surface characteristics. While the nanocrystalline form of rutile and T-Nb2O5 oxides together with a portion of amorphous TiO2 (Nb2O5) oxides were found on the surfaces of the samples of HT series [4], other crystalline form(s) of
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
