COMPARATIVE ANALYSIS OF TiO2 NANOTUBE LAYERS FORMED BY SINGLE- AND TWO-STEP ANODIZATION: SURFACE MORPHOLOGY, CORROSION RESISTANCE, AND CELLULAR RESPONSE

Abstract

This study examines the influence of anodization procedures on the formation and properties of TiO₂ nanotube layers on commercially pure titanium (cp-Ti) for biomedical implant applications. Both single-step (TiO2 1S) and two-step (TiO2 2S) anodization produced nanotubular structures composed of anatase and rutile phases, with the two-step process yielding more uniform and vertically aligned nanotubes. Mechanical testing indicated an increase in surface hardness, while electrochemical analyses demonstrated enhanced corrosion resistance, particularly for the TiO2 2S sample. Furthermore, TiO2 2S surfaces promoted superior cell adhesion and spreading, with well-developed filopodia and lamellipodia. Overall, the two-step anodization produces a more stable, oxygen-rich oxide layer with improved durability and biocompatibility, highlighting its potential for bone implant applications.