Biomedical Engineering Reference
In-Depth Information
37.4.2
Applications and Development of
Nano-HA/Collagen Scaffolds for Bone Tissue
Engineering
We have already developed osteogenic cells/nano-HA/collagen-
based scaffold composites, and
in vitro
cellular functions of these
materials have demonstrated that the scaffolds support cellular
growthandrelatedfunctionswellandleadtonewboneformation.
47
More recently, a three-dimensional bone-resembling scaffold pre-
pared using nano-HA/collagen/PLA/osteoblasts composites has
been developed.
58
This system supports cellular adhesion, prolif-
eration, and migration. Interestingly, cells grown on this mater-
ial were observed to penetrate deep into the matrix, to a depth
of about 200-400 mm. Within a short period, probably due to
both the compositional and structural similarity to natural bone,
this material can provide a promising cell/scaffold for bone tissue
engineering.
22
Scaffolds loaded with growth factor have been shown to reg-
ulate cellular growth and related functions in a better way.
59
Growth factors can be effectively delivered to a bone defect through
nanocomposites, and
in vivo
the e
cacy of such methods has been
evaluated.
56
The
in vivo
performance of the nanocomposite with
recombinant human bone morphogenetic protein-2 (rhBMP-2) is
better than that of the nanocomposite without rhBMP-2, which
implies its e
cacy as a good bone graft. The e
cacy in bone regen-
eration of such a scaffold combined with bone marrow mesenchy-
malstemcellswasalsoevaluated.
60
Itwasfoundthattheimplanted
scaffold could enhance and accelerate bone formation in segmen-
tal defects in rabbits. These experimental results indicate that an
effective bone graft should consist of an osteoconductive matrix in
conjunctionwithosteogeniccellsandosteoinductivegrowthfactors
withastructure,compositionandphysicochemical,mechanical,and
biologicalfeatures analogousto natural bone.
22
Bone tissue engineering using nano-HA/collagen composites is
still, however, in its infancy, although our knowledge in this area
is expanding. Although
in vitro
and
in vivo
evidence strongly sup-
ports the effective use of the biomimetic nanocomposites as bone
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