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Abstract
Molecular modeling could serve as a useful technique for
predicting the structure of new materials. Modeling work provides a
complete description for the molecular structure and even leads to the
discovery of a new material without consuming more chemicals or
spending time and efforts.
In the present work molecular modeling was used to provide
complete molecular description for the interaction of chitosan with
hydroxyapatite. There are 9 schemes to describe such interaction by
applying the molecular modeling with personal computer, and using
the physical interaction through active sites between chitosan and
hydroxyapatite.
The obtained results revealed that, there is no electron transfer
and subsequently no ionization, while a change in partial charge took
place which in turn increased the total dipole moment. Applying of
QSAR for proposed structures, indicate that, the scheme 9 (the final
proposed structure) is more biologically active than other schemes.
And hence makes it suitable for biological application.Consequently, chitosan/ hydroxyapatite composites were
synthesized following the wet spinning method. The prepared
composites were characterized by FTIR.
The selected composites were investigated by XRD and SEM
supplemented with EDX.While the biological activity was tested
through immersion in SBF for 7 days of 24 hours intervals. Water
uptake and degradation of the selected composites were performed
for the same time sequence. The developed biolayers were
charactcterized by SEM and EDX.FTIR spectroscopy recorded the occurrence of PO4 bands in
the composites proving its ability to interact with the surrounding
molecules.
The obtained results show that the synthesis of chitosan
/hydroxapatite composites in fibers form posses high surface area,
accordingly they are expected to interact effectively with the
surrounding media.
Biological activity of the selected composites is tested by soaking in
the simulated body fluid (SBF), which is in a good agreement with
the presented model. Accordingly this composite is biologically
active and could be used for bone substitution.
Correlating both modeling and experimental work revealed that the
proposed theoretical structure indicates a composite dimension of
about 1-2 nm. On the other hand, the prepared composite in the form
of fiber having large surface area, which imparts the biological
activity, is in a good agreement with the modeling work. . The
biological activity tested biochemically is a good indicator for the
structural morphology played by its fibers .The other composites
recorded comparatively inferior activity