In this study, ordered and uniform TiO 2 nanotubular structures were obtained on the surface of the Ti15Mo alloy by anodic oxidation. The amorphous state of TiO 2 nanotubes formed under different anodization conditions was investigated. Crystallization of TiO 2 into anatase phase occurs during annealing at temperatures of around 400°C, whereas anatase to rutile transformation starts around 500°C and is completed at 800°C. Phase transformations in annealed samples led to morphological changes of tubular nanostructures, suggesting that the oxide layer formed at the nanotube/substrate interface serves as nucleation sites for more stable phases of TiO 2. The proliferation of fibroblasts cells under annealing conditions of 450°C, and of untreated samples (control group), was evaluated after 1, 4, and 7 days in cell culture using fluorescence microscopy images. A gradual increase in the number and size of cells was observed, indicating a nontoxic alloy. There was also better surface coverage on anodized samples compared with the untreated group; as well as increased development of the cytoskeleton in samples after anodization. The results of this study showed that the growth of TiO 2 nanotubular structures associated with annealing allow better cell adhesion on the Ti15Mo alloy surface.
Ligas de titânio são utilizadas para aplicações biomédicas devido às excelentes propriedades mecânicas, resistência à corrosão e biocompatibilidade. No presente trabalho foram analisadas a microestrutura e as propriedades mecânicas da liga Ti-30Ta com diferentes níveis de compressão. A liga foi obtida por fundição em forno a arco voltaico com atmosfera inerte de argônio, homogeneizada, forjada e solubilizada. Para caracterização da liga Ti30Ta foram utilizadas técnicas de difração de raios-X (DRX) em temperatura ambiente e com aquecimento, calorimetria diferencial de varredura (DSC), microscopia eletrônica de transmissão (TEM) e compressão. As amostras deformadas em 19%, 22% e 44% foram avaliadas usando as técnicas de DRX, microscopia óptica e microdureza. A liga apresentou transformação alotrópica a uma temperatura próxima de 650 °C e microestrutura do tipo α''. A compressão resultou no cisalhamento da amostra de 44% e valores de dureza próximos para as demais amostras analisadas.Descritores: Ligas; Titânio; Propriedades Físicas e Químicas; Difração de Raios-X.
Bulk and surface properties are very important for materials used in biomedical applications. The development of new surface treatments, such as antibacterial coatings can directly affect the response of the surface. The purpose of this study was the development of antibacterial coating on the Ti7.5Mo alloy surface combining TiO 2 nanotubes with silver nanoparticles incorporation using polydopamine assisted immobilization technique. Surface characterization analysis showed that silver nanoparticles were successfully immobilized. The concentration established was bactericidal, i.e., no bacteria grew after incubation. In vivo results showed that silver incorporation on the surface containing TiO 2 nanotubes did not cause altered locomotor activity in zebrafish. On the other hand, it affected the cell adhesion on the surface. Thus, these results confirm the hypothesis that silver nanoparticles were totally incorporated to polydopamine on the surface containing TiO 2 nanotubes and acted as the main mechanism the death of the bacteria by contact. The antibacterial activity of the coating was investigated on Escherichia
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.