Cellular behavior on TiO2 nanonodular structures in a micro-to-nanoscale hierarchy model

Biomaterials. 2009 Oct;30(29):5319-29. doi: 10.1016/j.biomaterials.2009.06.021. Epub 2009 Jul 9.

Abstract

Biological tissues involve hierarchical organizations of structures and components. We created a micropit-and-nanonodule hybrid topography of TiO(2) by applying a recently reported nanonodular self-assembly technique on acid-etch-created micropit titanium surfaces. The size of the nanonodules was controllable by changing the assembly time. The created micro-nano-hybrid surface rendered a greater surface area and roughness, and extensive geographical undercut on the existing micropit surface and resembled the surface morphology of biomineralized matrices. Rat bone marrow-derived osteoblasts were cultured on titanium disks with either micropits alone, micropits with 100-nm nodules, micropits with 300-nm nodules, or micropits with 500-nm nodules. The addition of nanonodules to micropits selectively promoted osteoblast but not fibroblast function. Unlike the reported advantages of microfeatures that promote osteoblast differentiation but inhibit its proliferation, micro-nano-hybrid topography substantially enhanced both. We also demonstrated that these biological effects were most pronounced when the nanonodules were tailored to a diameter of 300nm within the micropits. An implant biomechanical test in a rat femur model revealed that the strength of bone-titanium integration was more than three times greater for the implants with micropits and 300-nm nanonodules than the implants with micropits alone. These results suggest the establishment of functionalized nano-in-microtitanium surfaces for improved osteoconductivity, and may provide a biomimetic micro-to-nanoscale hierarchical model to study the nanofeatures of biomaterials.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Biocompatible Materials / chemistry*
  • Cell Differentiation
  • Cell Proliferation
  • Cells, Cultured
  • Male
  • Mesenchymal Stem Cells / cytology*
  • Mesenchymal Stem Cells / physiology
  • Nanostructures / chemistry*
  • Nanostructures / ultrastructure*
  • Osseointegration / physiology*
  • Osteoblasts / cytology*
  • Osteoblasts / physiology
  • Rats
  • Rats, Sprague-Dawley
  • Surface Properties
  • Titanium / chemistry*

Substances

  • Biocompatible Materials
  • titanium dioxide
  • Titanium