Biomedical Engineering Reference
In-Depth Information
OH
OH
O
O
*
*
O
O
O
O
OH
+
OH
*
*
NH
2
NH
2
n
n
Chitosan
O
O
O
n
80
°
C/H
2
O/24 h
OH
OH
O
O
*
*
O
O
O
O
OH
OH
*
*
NH
NH
n
n
O
OH
OH
O
n
Figure 4.10
Reaction of cross-linked PEG hydrogel. (From Kiuchi, H., Kai, W. H., and Inoue, Y. 2008.
J Appl Polym Sci
107:
3823-3380. With permission.)
stomach and intestinal solutions, which can be a better biomaterial than chitosan in the
development of orally sustained drug delivery devices.
4.3 Multiple Component Network
4.3.1 Hybrid Cross-linking Network
4.3.1.1 Chitosan/Protein Cross-Linking Network
4.3.1.1.1 Chitosan/Collagen Hybrid Cross-Linking Network
As a tissue-engineering scaffold, chitosan/collagen hybrid cross-linking networks show
several advantages, including uniform and porous ultrastructure, less water absorption,
small interval porosity, and high resistance to collagenase digestion. Incorporation of
collagen into a chitosan matrix tends to increase the pore size and density and improve the
structural homogeneity, which is due to the improvement of the structural stability of the
matrices by chitosan in the chitosan/collagen cocross-linking network. The large number
of amino groups on the chains of chitosan functions as a cross-linking bridge to increase
overall matrix integrity by reinforcing the structure and cross-linking efficiency of GA in
the scaffolds [112,113]. Gao and coworkers [114] found that the GA treatment has an influ-
ence on the morphology of the chitosan/collagen network scaffold. After cross-linking, the
Search WWH ::
Custom Search