Biomedical Engineering Reference
In-Depth Information
Its major composition is calcium orthophosphate nanoparticles, which mimics the nanostructure,
composition, and performance of human bone. nanOss
is remodeled over time into human bone
with applications in sports medicine, trauma, spine, and general orthopedics [25] . Ostim
s
(Osartis
GmbH & Co. KG, Obernburg, Germany) is another popular commercial formulation. It is a ready-
to-use injectable paste that received CE (Conformite Europeans) approval in 2002. Ostim
s
s
is a
suspension of synthetic nano-HA in water, prepared by a wet chemical reaction [26] . Ostim
can
be used to treat metaphyseal fracture and cysts, alveolar ridge augmentation, osteotomies, etc.
[25,27
s
37] .
Although inorganic and organic substances show potential to promote bone regeneration, they
have inferior mechanical properties. Bone is composed of both collagen (mainly type I) and miner-
alized substance (mainly HA), therefore, a biomimetic scaffold should contain both inorganic and
organic components. Kim et al. [38] demonstrated that a rapid screening tool for potential biomi-
metic analogs of collagen mineralization and the nanoscopic protocol could accelerate the applica-
tion of Collagen-HA in bone regeneration. Recently, another study showed that chondroitin sulfate
(CS) combined with nano-HA exhibited the potential to mimick native bone extracellular matrix
(ECM) to promote bone regeneration [39] . These findings show that tissue engineering based on
the nanotechnology can become a breakthrough approach to reconstructing bone deformities in a
more effective and less traumatic way.
As it relates to craniofacial reconstruction, the design of polymer scaffolds with defined
mechanical and degradative properties has opened a new avenue to cartilage reconstruction.
Cartilage destruction is associated with trauma and with degenerative articular cartilage destruction
at the temporomandibular joint. The limited capacity of cartilaginous tissue to regenerate and the
lack of inductive molecules have focused interest among researchers and manufacturers in develop-
ing engineered cartilage. Cartilage itself is avascular and has relatively limited ability for intrinsic
repair. A pilot clinical study showed that a newly developed biomimetic osteochondral scaffold
with nucleating collagen fibrils along with HA nanoparticles could be used to repair femoral con-
dyle defects of knee joints. Magnetic resonance imaging (MRI) demonstrated good short-term
stability of the scaffold. Histologic analysis showed the formation of subchondral bone without the
presence of biomaterials. This result is encouraging and should be a cue for TMJ defects repair
[40] . Gene therapy approaches based on nanotechnology are promising for growth factor signaling
mediated cartilage regeneration. As shown by Erisken et al. [41] , osteochondral tissue regeneration
could be induced with nanofibrous scaffolds fabricated with two different layers that were respec-
tively conjugated with insulin (for chondrogenic differentiation) or with A-glycerophosphate
(for osteogenic differentiation). After being seeded on this mimetic scaffold, adipose-derived stem
cells could be induced to chondrogenic cells at insulin-rich location and to osteogenic cells at a
A-glycerophosphate-released region. This approach may also be applied for regenerating complex
craniofacial tissues such as TMJ [41] .
20.3 Nanotechnology for periodontal regeneration
Periodontal disease leads to destruction of the periodontium: alveolar bone, cementum,
the
periodontal
ligament, and gingiva. Effective treatment
for periodontal
tissue regeneration
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