Self-organized Titania Nanotubes on Curved Surfaces for Bioimplant Applications
摘要
Free-form and curved titanium surfaces have broad applications in orthopedic implants due to their adaptability and biocompatibility. Enhancing cell adhesion and proliferation on curved surfaces can be achieved by engineering a controlled surface roughness and enhancing wettability. To achieve this goal, the fabrication of TiO2 nanotube arrays (TNTs) on a curved surface may be considered a promising solution. In this study, TNTs were fabricated on curved Ti-6Al-4 V surfaces using an anodization process assisted by a conformal cathodic counterpart. The influence of electrode geometry, anodization voltage, and time on nanotube morphology was systematically analyzed. Results revealed that increasing the anodization voltage from 40 to 80 V increased nanotube diameter (62 to 188 nm) and wall thickness (6 nm to 28 nm). Anodizing time significantly affected nanotube stability at higher voltages, with 80 V and 90-min yielding crack-free, stable nanotubes. The contact angle decreased from 49 to 17° with increasing nanotube diameter due to enhanced surface area and capillary forces. Comprehensive analyses, including SEM, EDX, XRD, profilometry, nanoindentation, and goniometry, revealed that surface morphology, roughness, and wettability play crucial roles in osseointegration. Mineralization studies in simulated body fluid, mimicking human blood plasma, demonstrated variations in apatite deposition based on electrolyte composition and surface properties. It can be concluded that TiO2 nanotube fabrication is influenced by the electrode's geometry, with the resulting surface morphology playing a significant role in surface roughness, enhancing the wettability, and surface energy, all of which are critical factors for achieving successful osseointegration of orthopedic implants.