Titanium Nanosurface Modification by Anodization for Orthopedic Applications

Abstract

Titanium is broadly used in orthopedic and dental applications mainly because of its optimal mechanical properties in load-bearing applications. However, insufficient new bone formation is frequently observed on titanium which sometimes leads to implant loosening and failure. For this reason, the objective of the present in vitro study was to modify the surface of conventional titanium to include nanostructured surface features that promote the functions of osteoblasts (bone-forming cells). This study focused on creating nanostructured titanium surfaces since bone itself has a large degree of nanostructured roughness that bone cells are accustomed to interacting with. In this study, the surface of titanium was modified by anodic oxidation techniques. The electrolyte used for anodization was hydrofluoric acid. Depending on acid concentration and anodization time, two kinds of different nano-architectures, either particulate or tube-like structures, were formed on the titanium surface. X-ray diffraction results confirmed that the titanium oxide formed on the surface of titanium was amorphous. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) were used to characterize the surface morphology. Cell adhesion studies showed that the anodized nanostructured titanium surface promoted osteoblast adhesion compared to non-anodized titanium. This result indicated that anodization may be a simple method to modify the surface of titanium implants to enhance bone-forming cell function thereby increasing orthopedic implant efficacy.

Application of anodized titanium for enhanced recruitment of endothelial progenitor cells

“…This process leads to the formation of protective TiO 2 nanostructures on the surface, which provides a natural environment for cell growth [ 5 ]. The increased thickness and stability of this formed oxide layer on titanium protect it from uncontrolled oxidation, chemical reactions and corrosion [ 6 ]. Topography of metal surface is easily changed by anodization [ 6 ].…”

“…The increased thickness and stability of this formed oxide layer on titanium protect it from uncontrolled oxidation, chemical reactions and corrosion [ 6 ]. Topography of metal surface is easily changed by anodization [ 6 ]. In this way, bioactivity and biocompatibility of the underlying metal is enhanced.…”

Microstructure analysis and wear behavior of titanium cermet femoral head with hard TiC layer

“…However, a main limit of titanium alloys is their poor tribological behavior, characterized by high coefficients of friction, severe adhesive wear with a strong tendency to seizing and low abrasion resistance (Abkowitz et al, 2005;Ceschini et al, 2008). Thus, a number of different surface modification techniques, such as ion implantation, physical vapor deposition, chemical vapor deposition, micro arc oxidation and plasma spraying, have been developed to improve the tribological properties of titanium alloy over the past 4 decades (Braceras et al, 2005;Krupa et al, 2007;Szymanowski et al, 2005;Kwon et al, 2007;Yao et al, 2005;Huang et al, 2004;Uzumaki et al, 2008;Beck et al, 2007;Stoch et al, 2005). It is believed that TiC coating has an ability to form strong bonds with the titanium substrate which could provide a superior hardness and wear resistance, and it can induce carbon atoms into the metal matrix to enhance the biocompatibility (Brama et al, 2002;Brama et al, 2007).…”

Nanometer‐scale surface modification of Ti6Al4V alloy for orthopedic applications

“…Surface roughness on the nanometer‐scale has been shown to favor promoting smooth connection between bone and the implants and reducing fibrous tissue encapsulation 5. However, conventionally processed (e.g., cast, forged, etc) titanium currently used for orthopedic and dental applications exhibits roughness only on a micrometer level but is smooth on a nanometer scale 7. An approach was therefore attempted to design the next‐generation of implants focusing on creating unique nanometer‐topography (or roughness) on the implant surface, simulating the nano‐structures such as collagen and hydroxyapatite in natural bone.…”