A multi-scaled hybrid orthopedic implant: bone ECM-shaped Sr-HA nanofibers on the microporous walls of a macroporous titanium scaffold

Nanotechnology. 2011 Jul 8;22(27):275603. doi: 10.1088/0957-4484/22/27/275603. Epub 2011 May 20.

Abstract

We report here, for the first time, a novel multi-scaled hybrid orthopedic implant material consisting of a macroporous Ti scaffold, whose macropores' walls have a microporous titania layer which is fully covered with nanofibers of Sr-doped hydroxyapatite (Sr-HA). The microporous titania layer is formed on and within the Ti scaffold by micro-arc oxidation, which firmly binds to the Ti substrate and contains Ca2+, Sr2+ and PO4(3-) ions. It is then hydrothermally treated to form Sr-HA nanofibers. During the hydrothermal treatment, Sr-HA nanoprisms nucleate from Ca0.5Sr0.5TiO3 pre-formed on the TiO2 and grow in length to nanofibers at the expense of Ca2+, Sr2+ and PO4(3-) ions that migrate from the TiO2. These Sr-HA nanofibers construct a network structure similar to the hierarchical organization of bone extracellular matrix (ECM), and the resulting nanofibrous surface displays a firm adhesion to substrate, superhydrophilicity and apatite-inducing ability. The induced apatite prefers to nucleate on the basal-faceted surfaces of Sr-HA nanofibers. The nanofiber-walled scaffold has a great potential for load-bearing orthotopic use.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acoustics
  • Bone and Bones / chemistry*
  • Calcium / analysis
  • Durapatite / chemistry*
  • Extracellular Matrix / chemistry*
  • Hydrophobic and Hydrophilic Interactions
  • Nanofibers / chemistry*
  • Nanofibers / ultrastructure
  • Oxidation-Reduction
  • Phosphorus / analysis
  • Porosity
  • Prostheses and Implants*
  • Strontium / analysis
  • Strontium / chemistry*
  • Temperature
  • Tissue Scaffolds / chemistry
  • Titanium / chemistry*
  • Water / chemistry
  • Wettability
  • X-Ray Diffraction

Substances

  • Water
  • Phosphorus
  • Durapatite
  • Titanium
  • Calcium
  • Strontium