Interaction of Human Osteoblast-Like Saos-2 and MG-63 Cells with Thermally Oxidized Surfaces of a Titanium-Niobium Alloy

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.

Cytocompatibility assessment of Ti‐Zr‐Pd‐Si‐(Nb) alloys with low Young's modulus, increased hardness, and enhanced osteoblast differentiation for biomedical applications

“…Also on pure Ti, a standard clinically used material for bone implantation, particularly in stomatological surgery, the proliferation of human osteoblast‐like cells of the Saos‐2 and MG‐63 lines was lower than on a TiNb alloy. At the same time, the cell growth on the TiNb alloy was significantly higher than on control cell culture polystyrene dishes, while on Ti, this number was similar or even lower in comparison with PS . Thus, it seems that the presence of β‐Ti phase in an alloy is excellent to obtain biocompatible materials.…”

“…Moreover, the protein conformation once adsorbed to the surface of both alloys is unknown, and it is a key point in the subsequent cell response. 15 Conversely, cell adhesion and spreading was lower on the glass coverslip, where more rounded cells were observed and lower levels of vinculin were quantified compared with both alloys. The higher contact angle of the glass coverslip (808) compared with that of the two alloys (57.68 and 64.88) can explain the differences in cell adhesion and spreading between the two different surfaces.…”

“…A possible explanation is that although fibronectin and albumin are components of the serum, they compete to be adsorbed on the same surface and the increase in fibronectin adsorption is balanced by the increase in albumin adsorption. Moreover, the protein conformation once adsorbed to the surface of both alloys is unknown, and it is a key point in the subsequent cell response …”

“…Osteoblast differentiation and extracellular matrix mineralization play an important role in osseointegration. OC, OPN, ON, and BSP are osteogenic genes expressed by Saos‐2 cells during the extracellular matrix maturation and mineralization . COLI is the major component of organic bone extracellular matrix, representing 90% of extracellular matrix proteins, and it is considered an early marker of osteoblast differentiation .…”

THE INTERACTION OF HUMAN OSTEOBLAST-LIKE Saos-2 CELLS WITH STAINLESS STEEL AND Si(100) COATED BY SILICALITE 1 FILMS

“…The human osteoblast-like Saos-2 cells were seeded on the sample surfaces as described in our earlier study [5]. Briefly, the samples were sterilized in a hot air sterilizer (2 hours, 120°C), inserted into 24-well cell culture plates, and seeded with the cells at a density of 15,000 cells/cm 2 and in 1 mL of McCoy s 5A medium with 15 % fetal bovine serum and 40 µg/mL of gentamicin.…”