Biomedical Engineering Reference
In-Depth Information
9
Biomaterials and Biotechnology
Schemes Utilizing TiO
2
Nanotube Arrays
Karla S. Brammer
1
, Seunghan Oh
2
, Christine J. Frandsen
1
and Sungho Jin
1
1
Materials Science & Engineering, University of California,
San Diego, La Jolla, California
2
Department of Dental Biomaterials, College of Dentistry,
Wonkwang University, Iksan,
1
USA
2
South Korea
1. Introduction
Ti and Ti alloys are corrosion resistant, light, yet sufficiently strong for utilization as load-
bearing and machinable orthopaedic implant materials. They are one of the few
biocompatible metals which osseo-integrate, provides direct chemical or physical bonding
with the adjacent bone surface without forming a fibrous tissue interface layer. For these
reasons, they have been used successfully as orthopaedic and dental implants (Ratner
2004). To impart even greater bioactivity to the Ti surface and enhance integration
properties, surface treatments such as surface roughening by sand blasting, formation of
anatase phase TiO
2
(Uchida et al. 2003), hydroxyapatite (HAp) coating, or chemical
treatments (Ducheyne et al. 1986; Cooley et al. 1992) have been employed. However, these
treatments are generally on the micron scale. Webster et al. (Webster et al. 2001; Webster,
Siegel, and Bizios 1999) reported that it is even more advantageous to create
nanostructured, in particular in the less than 100nm regime, surface designs for
significantly improved bioactivity at the Ti implant interface and for enhanced cell
adhesion. Since then, advances in biomaterial surface structure and design, specifically on
the nanoscale, have improved tissue engineering in general. This chapter is a report on
titanium dioxide (TiO
2
, or Titania) nanotube surface structuring for optimization of
titanium (Ti) implants utilizing nanotechnology.
The main focus will be on the unique 3-D tube-shaped nanostructure of TiO
2
and its effects
on creating profound impacts on cell behavior. We will also shed light on the effects of
changing the nanotube diameter size and optimizing the geometry for enhanced cell
behavior. This work focuses on the tissue specific areas of cartilage and bone. Specifically,
we will discuss how the desired cell behavior and functionality are enhanced on surfaces
with TiO
2
nanotube surface structuring. Here we reveal how the TiO
2
surface nano-
configurations are advantageous in various tissue engineering and regenerative medicine
applications, for osteo-chondral, orthopedic, and osteo-progenitor implant applications
discussed here and beyond. This chapter will also shed light on future applications and the
direction of nanotube surface structuring.
