Antimicrobial Properties of TiNbSn Alloys Anodized in a Sulfuric Acid Electrolyte

Abstract

TiNbSn alloy is a high-performance titanium alloy which is biosafe, strong, and has a low Young’s modulus. TiNbSn alloy has been clinically applied as a material for orthopedic prosthesis. Anodized TiNbSn alloys with acetic and sulfuric acid electrolytes have excellent biocompatibility for osseointegration. Herein, TiNbSn alloy was anodized in a sulfuric acid electrolyte to determine the antimicrobial activity. The photocatalytic activities of the anodic oxide alloys were investigated based on their electronic band structure and crystallinity. In addition, the cytotoxicity of the anodized TiNbSn alloy was evaluated using cell lines of the osteoblast and fibroblast lineages. The antimicrobial activity of the anodic oxide alloy was assessed according to the ISO 27447 using methicillin-susceptible Staphylococcus aureus, methicillin-resistant Staphylococcus aureus, and Escherichia coli. The anodic oxide comprised rutile and anatase titanium dioxide (TiO2) and exhibited a porous microstructure. A well-crystallized rutile TiO2 phase was observed in the anodized TiNbSn alloy. The methylene blue degradation tests under ultraviolet illumination exhibited photocatalytic activity. In antimicrobial tests, the anodized TiNbSn alloy exhibited robust antimicrobial activities under ultraviolet illumination for all bacterial species, regardless of drug resistance. Therefore, the anodized TiNbSn alloy can be used as a functional biomaterial with low Young’s modulus and excellent antimicrobial activity.

TiNbSn stems with gradient changes of Young’s modulus and stiffness reduce stress shielding compared to the standard fit-and-fill stems

“…Osteoblast progenitor cells are expressed in the endosteum of the bone marrow [ 42 ]. The TNS alloy after anodic oxidation treatment promotes bone formation by proliferating and activating osteoblasts in the endosteum of the bone and exerts an antibacterial effect through photocatalytic performance owing to sodium tartrate and sulfuric acid [ 53 – 55 ]. The TNS alloy is considered to be a promising orthopaedic implant material owing to the low Young’s modulus and functional improvement by surface modification.…”

Silver-Doped Titanium Oxide Layers for Improved Photocatalytic Activity and Antibacterial Properties of Titanium Implants

“…Electrolytes A and B have been previously documented to produce phosphorus-doped anatase phase and mixed phase oxides on commercially pure titanium substrates [ 3 , 15 , 26 ]. Electrolyte C is 1 M sulfuric acid, which has been commonly used in other titanium anodization studies [ 34 , 35 , 36 ]. Silver nitrate (99.85%, Thermo Fisher Scientific, Waltham, MA, USA) was added to its saturation limit in each of these electrolytes to create the remaining A + Ag, B + Ag, and C + Ag electrolytes ( Table 1 ) used in this study.…”

“…Two of these anodization processes produced phosphorus-doped oxides due to phosphoric acid being an electrolyte component. The third anodization process involved a 1M sulfuric acid electrolyte that has been commonly used in other titanium anodization studies [ 34 , 35 , 36 ]. The primary study objective was to assess the benefits of silver-doping additions to established anodization processes that have already been shown to exhibit beneficial PCA and bacterial responses.…”