Multifunctional TaCu-nanotubes coated titanium for enhanced bacteriostatic, angiogenic and osteogenic properties

In this study, multifunctional tantalum copper composite nanotubes (TaCu-NTs) were coated on titanium for enhanced bacteriostatic, angiogenic and osteogenic properties. Three coatings of Ta, TaCu1 (Ta: Cu = 4:1 at.%), and TaCu2 (Ta: Cu = 1:1 at.%) were deposited on titanium by magnetron sputtering. The bare titanium and the three coatings were subsequently anodized into four kinds of nanotubes (NT) of TNT, Ta-NT, TaCu1-NT, and TaCu2-NT, respectively. The released copper ions measured by inductively coupled plasma atomic emission spectroscopy (ICP/AES) presented that TaCu2-NT coating released the highest amount of copper ions, which led to the best bacteriostasis against Escherichia coli and Staphylococcus aureus. Potentiodynamic polarization tests clarified that Ta-NT showed the highest corrosion resistance, followed by TaCu1-NT and TaCu2-NT. TaCu2-NT showed not only the best angiogenic property in terms of cell migration, tube formation, and real-time quantitative polymerase chain reaction (RT-qPCR) of human umbilical vein endothelial cells (HUVECs), but also the best osteogenic property in terms of cell viability, alkaline phosphatase activity, and mineralization of MC3T3-E1 cells. Therefore, TaCu2-NT coating has a greater potential than the other coatings of TNT, Ta-NT and TaCu1-NT in promoting bacteriostasis, angiogenesis and osteointegration for titanium implants.