In alternative embodiments, the invention provides products (articles) of manufacture comprising nanostructures such as nanotubes having a surface comprising tantalum. In alternative embodiments, products of manufacture of the invention include nanostructures, e.g., nanotubes, nanowire, nanopore, and the like comprising a surface layer of tantalum. In alternative embodiments, products or articles of manufacture of the invention are bioimplants, and the tantalum-surface-coated nanostructures of the invention provide increased bioactivity and bone forming ability. In alternative embodiments, products or articles of manufacture of the invention, e.g., bioimplants, comprising the tantalum-surface-coated nanostructures of the invention are used for in vitro, ex vivo and in vivo testing, implants, biomedical devices and therapeutics.
