Enzyme-Mediated Mineralization of TiO₂ Nanotubes Subjected to Different Heat Treatments

Abstract

Surface-modified titanium (Ti) and titanium alloys with physical topography and bioactive components mimicking those of bone tissues have attracted increasing interest as biomaterials for accelerating osseointegration. In this study, an enzyme-mediated mineralization system containing an organic phosphate is used to form a coating of calcium phosphate on titanium dioxide (TiO 2 ) nanotubes heat-treated at different temperatures (350, 450, and 550 °C). Surface characterization using analytical techniques shows that this system can lead to the deposition of an amorphous calcium phosphate layer on the TiO 2 nanotube (TNT) surface while preserving the original nanotopography. In this respect, the heat treatment of TNT plays an essential role in the formation of the calcium phosphate layer, with TNT annealed at 450 °C having the best mineralization results. The synergistic effect of the TNT topography and chemical cues of the calcium phosphate layer improves adhesion, proliferation, and differentiation of pre-osteoblasts in vitro when compared with surfaces with only one of these features. This hybrid coating can thus potentially enhance the osseointegration of titanium-based implants.

A biomimetic approach to evaluate mineralization of bioactive glass-loaded resin composites

“…Moreover, MEM used in this study contained several enzymes, such as alkaline phosphatase. Previous study suggested that this enzyme may slow down the formation of HA [41] and stabilize the minerals in the precursor phases, such as ACP or OCP. However, HEPES in SHARP solution could keep the pH stable at 7.4 as seen from Figure 4.…”

Tubular nanomaterials for bone tissue engineering

“…Yun et al used an enzyme-mediated mineralization system to form a calcium phosphate (CaP) coating on a titanium modified surface annealed at high temperature. 126 The combination of the TNT's nanotopography as a physical cue and a bioactive CaP layer as a chemical cue endowed synergistically improved preosteoblast proliferation and differentiation in comparison to surfaces with only TNT topography or CaP coating. Bartkowiak et al reported that surface functionalization with an HA coating improved the performance of current titanium-based implants.…”