Biomedical Engineering Reference
In-Depth Information
Figure 6.3
Scanning electron microscopy image of reconstituted
mineralized collagen I fibrils. An example of an organic-
inorganic nanostructural composite, mimicking the
extracellular matrix of bone tissue on the nanometer scale.
Reprinted from Ref. [689] with permission.
Nanodimensional crystals of HA appeared to be suitable for
intra-osseous implantation and offered a potential to formulate
enhanced biocomposites for clinical applications [694]. Thus,
the biocompatibility of chitosan in osteoblast cell culture was
significantly improved by addition of nano-sized HA [695]. Similar
finding is valid for nanodimensional HA/polyamide biocomposites
[630]. Further details on nanodimensional biocomposites might
be found in an excellent review [36]. More to the point, a more
general review on applications of nanodimensional biomaterials in
orthopedics is also available [696], where the interested readers are
referred.
6.4.4
Biocomposites with Collagen
The main constituent of the bioorganic matrix of bones is type I
collagen (Table 6.1) with molecules about 300 nm in length. The
structural and biochemical properties of collagens have been widely
investigated and over 25 collagen subtypes have been identified [697,
698]. This protein is conducive to crystal formation in the associated
inorganic matrix. It is easily degraded and resorbed by the body
and allows good attachment to cells. Collagen alone is not effective
Search WWH ::
Custom Search