Biomedical Engineering Reference
In-Depth Information
Figure 10.4
TEM micrograph of multilayered hydroxyapatite/
diamondlike carbon nanocomposite on Si (100), including
hydroxyapatite, diamondlike carbon, diamondlike carbon-
silver, titanium carbide, titanium carbonitride, and titanium
nitride layers [47].
Diamondlike carbon is an ideal surface coating mainly for
prosthetic joints, because it is atomically smooth, low friction,
wear resistant, inert, and immune to scratching by third body wear
particles [34, 47], and it prevents the release of metal ions into the
surrounding tissues. Guglielmotti
et al
. [20] found that DLC-coated
zirconium and zirconium implants exhibited better tissue responses
than titanium or aluminum implants. DLC-coated steel fracture
ixation rods implanted in a human body for 7 months were found to
prevent rod corrosion and metal ion release [67].
10.2 CarbonNanotubes
The new carbon nanotubes are ultra lightweight and have excellent
thermal and chemical stability. Compared with conventional carbon,
carbon nanotubes are stronger and more lexible and have a higher
tensile strength-to-weight ratio [1]. Medical applications of the
carbon nanotubes in biosensors, drug delivery systems, scaffolds, and
biomaterials are very promising. Carbon nanotubes are composed of
the convoluted graphene lattice and can be in the form of a single-
walled carbon nanotube (SWCNT) or multi-walled carbon nanotubes
(MWCNTs), composed of single and multiplanes, respectively
