In this study, we anodized a TiNbSn alloy with low Young’s modulus in an electrolyte of sodium tartrate with and without hydrogen peroxide (H2O2). The photo-induced characteristics of the anodized alloy were analyzed for crystallinity and electrochemical conditions with comparisons to the effect with the addition of H2O2. The antibacterial activity was evaluated using methicillin-resistant Staphylococcus aureus and other pathogenic bacteria according to ISO 27447, and time decay antibacterial tests were also conducted. The anodized oxide had a porous microstructure with anatase- and rutile-structured titanium dioxide (TiO2). In contrast, the peaks of rutile-structured TiO2 were accelerated in the anodized TiNbSn alloy with H2O2. The formation of hydroxyl radicals and methylene blue breaching performance under ultraviolet irradiation was confirmed in the anodic oxide on TiNbSn alloy with and without H2O2. The anodic oxide on TiNbSn alloy had a robust antibacterial activity, and no significant difference was detected with or without H2O2. We conclude that anodized TiNbSn alloy with sodium tartrate electrolyte may be a functional biomaterial with a low Young’s modulus and an antibacterial function.

ABSTRACT. Six strains of feline immunodeficiency virus (FIV) classified into subtypes A, B and D were examined by cross-neutralization test using Kumi-1 cells (CD4 + , CD8 -, and CD9 + ), an interleukin-2 dependent feline T-lymphocyte cell line. Neutralizing activities against these six FIV strains were also investigated in 50 FIV-antibody-positive serum samples collected from different geographical regions in Japan. The cross-neutralization test revealed that antisera against the six strains tended to possess high neutralizing activity against the homologous strain. These antisera were also capable of neutralizing viral strains of the same subtype. However, some of the antisera were broadly crossreactive with all six FIV strains. Serum samples collected from naturally infected cats in the field showed various neutralization patterns for the six FIV strains. These observations reflect the antigenic diversity in FIV strains prevailing in the field. There were also broadly crossreactive serum samples, and 36% (18/50 samples) showed neutralization for all six FIV strains. -KEY WORDS: cross-neutralization test, FIV, subtype.

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.