Self-organized niobium oxide nanocones with nano-sized tips are prepared by anodization of niobium in the presence of an electrolyte such as hydrofluoric acid (HF) (aq.) . Dimensions and integrity of the bulk nanostructures formed are strongly dependent on potential, temperature, electrolyte composition, and, anodization times. Accordingly, the morphology, topology, uniformity and bioactivity of the niobium oxide nanostructures formed can be readily adjusted by adjusting these anodization parameters. A bioactive form of crystalline niobium oxide is formed by anodizing niobium metal in the presence of an , electrolyte that includes HF and at least one salt such as Na2SO4 or NaF. One property of bioactive niobium oxide formed by anodizing niobium metal in the presence of HF (aq. ) is it ability to interact with hydroxylapatite.