Proliferation and differentiation parameters of human osteoblasts on titanium and steel surfaces

Abstract

Commercially pure titanium (cpTi), titanium alloys, and steel are often used for dental and orthopedic implants. In these applications titanium is considered the "gold standard." However, tissue reactions around titanium implants and the changing trend to leave orthopedic devices in the body have led to a new examination of the preferred material. This in vitro study tested the behavior of osteoblasts on cpTi, Ti-6Al-7Nb, and stainless steel with surface designs similar to clinical implants. After surface characterization by scanning electron microscopy and profilometry, cell proliferation and the differentiation parameters of alkaline phosphatase (ALP) activity and osteocalcin were measured. For all materials tested, the growth curves showed a similar kinetic. On Ti-6Al-7Nb, ALP activity was significantly lower when compared with steel, and cpTi and did not change over the time. ALP activity increased moderately on steel and cpTi. Osteocalcin levels were higher on both titanium materials than on steel. Based on undisturbed cell growth and the relatively high alkaline phosphatase and osteocalcin levels, we suggest that cpTi provides the best biocompatibility with regard to proliferation, in addition to more reliable early and late differentiation markers of human osteoblasts in vitro.

Combining 3D human in vitro methods for a 3Rs evaluation of novel titanium surfaces in orthopaedic applications

“…The in vitro assessment of materials has an advantage of having relatively well‐controlled variables, which enable the investigation of parameters otherwise difficult to study in vivo (Schmidt et al, 2001). The use of human cells is another advantage—here an MG63 osteoblast‐like cell line (Chang et al, 2014; Gittens et al, 2011; Madhankumar et al, 2014; Tan et al, 2011; Yazici et al, 2013; Yeung et al, 2013) and primary human osteoblast cells (Balani et al, 2007; Gough et al, 2004; Jones et al, 2007; Rice et al, 2003) were used.…”

“…The use of human cells is another advantage—here an MG63 osteoblast‐like cell line (Chang et al, 2014; Gittens et al, 2011; Madhankumar et al, 2014; Tan et al, 2011; Yazici et al, 2013; Yeung et al, 2013) and primary human osteoblast cells (Balani et al, 2007; Gough et al, 2004; Jones et al, 2007; Rice et al, 2003) were used. Although the MG63 cell line is immortalized (Schmidt et al, 2001), such cells are suitable for establishing initial experimental conditions. Normal primary human osteoblasts were used thereafter to study markers including differentiation (with the caveat that all human primary cells are inherently variable in the genetic and phenotypic response) to identify whether similar responses were observed across the orthopaedic surfaces.…”

Improved Biocompatibility of Titanium–Zirconium (Ti–Zr) Alloy: Tissue Reaction and Sensitization to Ti–Zr Alloy Compared with Pure Ti and Zr in Rat Implantation Study

“…1,14) Commercially pure Ti has generally good biocompatibility, [14][15][16][17] but its mechanical strength is insufficient for use in artificial hip joints. 16,20) Furthermore, the appearance of increased wear debris from Ti has been associated with tissue inflammation.…”

“…The use of Ti alloys is increasing due to their excellent mechanical strength, corrosion resistance, and good biocompatibility. [14][15][16][17] These properties are attributable mainly to the formation of a stable titanium oxide (TiO 2 ) layer on the surface. 18,19) However, the mechanical/tensile strength of commercially pure Ti is insufficient for its use as an artificial hip joint, pin, or screw, 20) and its wear resistance is also inferior to that of stainless steels and Co-Cr alloys.…”

Untitled

“…Therefore, studies since the late 1980s have also focused on the osteoconductive nature of hydroxyapatite coatings [15]. The significance of surface chemistry is defined by the specific cellular responses to different bulk metals [16,17]. Some of the newer approaches to changing the reactivity of the pure(c.p.)…”