Biomedical Engineering Reference
In-Depth Information
Fig. 6.7
SEM images of pine wood (
a
,
b
,
c
,
f
) and rattan (
d
,
e
): (
a
,
d
)nativeforms;(
b
,
e
)
pyrolyzed; wood-derived hydroxyapatite: (
c
) parallel fastened hydroxyapatite microtubes; (
f
)
needle-like hydroxyapatite nuclei grown on the microtube surface. Reproduced with permission
of The Royal Society of Chemistry [
246
], Figs. 1(a, b, c, d) and 10
the pinewood scaffold, measured parallel to the channels ranges from 2.5 to 4 MPa,
perpendicular to the channels 0.5-1 MPa. The pore size of the rattan-derived scaf-
fold is 100-300
m. Pinewood
processing resulted in a bimorphic hydroxyapatite: ordered parallel microtubes 100-
150
m together with sizes ranging form 0.01 to 100
m wide with a hollow core and, as shown in the insert
of f, needle-like nuclei grown crystals, typical aspect of a dissolution/precipitation
crystallization process (Fig.
6.7
). The pores were proved to have a high degree of
interconnectivity.
The authors do not report any in vitro or in vivo or clinical testing. This fabrica-
tion technique, however, was discussed into some detail because it is a stimulating
topic: using Nature as template. It is not unthinkable to use a plant structure, forced
into a mechanically desired morphology during growth, as bone scaffold template.
Following the same biomimicking philosophy, cell-produced aligned collagenous
matrices have been proposed as scaffolding material to enhance ligament and tendon
healing [
247
]. Phantasy, for the time being yes but part of a bioengineer's dream.
m long and 15-30
