SiO2 loading into polydopamine-functionalized TiO2 nanotubes for biomedical applications

摘要

A recent advancement in bone therapies is the development of advanced implants from arrays of titania nanotubes, which are fabricated with self-ordering electrochemical anodization of a Ti substrate. We have fabricated a novel interface by coating an anodized Ti substrate with polydopamine. This interface is suitable for the efficient incorporation of SiO2 nanoparticles into the porous layer of TiO2 nanotubes formed on the underlying Ti substrate. The results of different characterization tests indicate that the nanoparticles are evenly incorporated into the titania nanotube arrays. Potentiodynamic polarization curves and electrochemical impedance spectra measurements in a solution of simulated body-fluid indicate that the composite layer of SiO2 nanoparticles and the titania-nanotube arrays were more corrosive-resistant than the layer of titania-nanotubes arrays. Its hydrophilic properties and surface roughness are enhanced with the incorporation of SiO2 nanoparticles. As shown by in-vitro cellular assays, cell attachment and alkaline phosphate activity on such composite layer improved. The polydopamine/anodization treatment of Ti substrates allows the quick integration of SiO2 with titania nanotubes to increase corrosive resistance and biocompatibility of the Ti substrate. This could be a new approach to investigating the collective effects of local chemistry of compounds, e.g., SiO2, and of local topography of titania nanotubes.