In vivo stability of biomaterial-based bone scaffolds often present a significant drawback in the development of materials
for tissue engineering purpose. Previously developed nanobiocomposite bone scaffold using alginate and nano cockle shell
powder has shown ideal characteristics. However, it showed high degradation rate and reduced stability in an in vivo
setting. In this study, we aim to observe the effect of cross-linking glutaraldehyde (GA) in three different concentrations
of 0.5%, 1% and 2% during the fabrication process as a potential factor in increasing scaffold stability. Microstructure
observations of scaffolds using scanning electron microscope (SEM) showed all scaffolds crossed linked with GA and
control had an ideal pore size ranging from 166.8-203.5 µm. Increase in porosity compared to the control scaffolds
was observed in scaffolds cross-linked with 2% GA which also presented better structural integrity as scored through
semi-quantitative methods. Tested pH values during the degradation period showed that scaffolds from all groups
remained within the range of 7.73-8.76. In vitro studies using osteoblast showed no significant changes in cell viability
but a significant increase in ALP enzyme levels in scaffold cross-linked with 2% GA. The calcium content released from
all scaffold showed significant differences within and between the groups. It can be concluded that the use of GA in the
preparation stage of the scaffold did not affect the growth and proliferation of osteoblast and use of 2% GA showed
improved scaffold structural integrity and porosity.
Biocompatibility and growth of osteoblast on bone scaffolds play an important role towards their therapeutic application.
The presence of oxidative stress generated by bone scaffolds highly influences osteoblast growth and its functional
performance. In this study in-vitro interaction of developed Alginate/Cockle Shell powder nanobiocomposite bone scaffold
on osteoblast with regards to cytotoxicity and oxidative stress are evaluated. Cytotoxicity studies using MTT assays
revealed a significant increase in viability of cultured osteoblast in the presences of the scaffold extracts. The growth of
osteoblast on the scaffold were not deterred with the presence of any major oxidative stress factors as determined through
oxidative stress profile studies using SOD, GSH and ROS assays. The nanobiocomposite scaffold evaluated in this study
shows promising use in regards to facilitating osteoblast proliferation, growth and viability.
Calcium carbonate (CaCO3
) plays a crucial role in influencing the growth of osteoblast. This study was conducted
to compare the performance of alginate/cockle shell powder nanobiocomposite (nCP) bone scaffold developed from
naturally occurring CaCO3 with alginate/calcium carbonate (CC) bone scaffold developed using synthetic CaCO3. The
study compares the performance of the scaffold in supporting the growth of osteoblast through in vitro evaluations as
well as initial biocompatibility observations through in vivo methods. Both scaffolds were developed using the mixture
of 40% alginate solution with either 60% of nano cockle shell powder or synthetic CaCO3 to obtain a three dimensional
scaffold structure. In vitro evaluation on calcium release and ALP enzyme activity was conducted on both scaffolds seeded
with osteoblast on day’s three, five and seven using commercial kits. In vivo observations using histological methods
were further conducted by implanting osteoblast seeded scaffold subcutaneously at the dorsum of 8 albino mice for 21
days. Findings from in vitro studies showed a significant increase (p < 0.05) in the release of calcium and ALP enzyme
activity in nCP scaffolds on day seven compared to days three and five of CC scaffold. Histological observations using
H&E and von Kossa staining showed infiltration and proliferation of osteoblast on both scaffolds as well as early stage
bone tissue formation. Formation of new blood vessels within the scaffolds was also observed in nCP scaffold. Both the
developed scaffolds were noted to support osteoblast growth and new tissue formation with better potentials displayed by
nCP scaffolds comparatively. This study shows that naturally occurring CaCO3 obtained from cockle shells in the form
of nano powder has good potentials to be used as a biomaterial for bone tissue engineering applications.