Biomedical Engineering Reference
In-Depth Information
9.5.6 Carbonated Hydroxyapatite-Gelatin Composite
Low interfacial bonding and ineffective stress transfer between the ceramic
filler and polymer matrix imposes limitations on the mechanical properties
of composite scaffolds. In an attempt to circumvent this problem, Arafat
et al.
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modified TCP using 3-glycidoxypropyl trimethoxysilane (GPTMS),
covalently-bonded the modified TCP with PCL by annealing at 120 1C for 2 h
and fabricated 3D composite scaffolds utilising FDM technology. The scaf-
folds were coated with CHA-gelatin with the aim of improving their osteo-
conductive properties. It was shown that the covalently bonded PCL-TCP
scaffolds had significantly higher compressive moduli and compressive yield
compared to non-covalently bonded PCL-TCP scaffolds. In vitro studies in-
dicated that CHA-gelatin composite coating on PCL-TCP scaffolds improved
the proliferation and osteoconductive
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capability
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9.5.7 Phlorotannin Conjugations
Further investigations into PCL-TCP scaffolds have examined the in vitro
response to the addition of phlorotannin conjugations (at 1, 3 and 5 wt%)
into 80 : 20 wt% PCL-TCP scaffolds.
60
The subsequent effects on physical
characteristics such as surface roughness, water absorption ability and
mechanical properties were analysed. The viability and differentiation of
osteoblast-like cells (MG63) was also investigated. A greater than four-fold
increase in cell attachment was observed in the phlorotannin treated groups.
Additionally, cell viability was also increased dramatically in the phloro-
tannin groups. Energy dispersive spectroscopy was used to examine the
amounts of elemental calcium and phosphorus. A marked increase was
shown in the phlorotannin 5 wt% group compared with the plain PCL-TCP
controls.
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.
9.6 Polycaprolactone-based Scaffolds as Drug
Carriers
9.6.1 Antibiotics
Teo et al.
61
explored the suitability of FDM fabricated PCL-TCP (80 : 20 wt%)
scaffolds as carriers for gentamicin sulfate (GS) to treat infected wounds. It
was demonstrated through in vivo studies that a PCL-TCP-GS scaffolds with
5 wt% of GS had inadequate bacterial-elimination ability while scaffolds
with 25 wt% of GS were shown to decrease cell viability due to the levels
being possibly toxic. An effective middle ground appeared to be scaffolds
with 15 wt% of GS, which were shown to eciently eliminate both Gram-
positive and Gram-negative bacteria within 2 h and had good biocompati-
bility with dermal fibroblasts.
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Murine full thickness wounds treated with
scaffolds containing 15 wt% GS showed greater healing rates than the
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