Application of Chitosan-Based Biomaterials in Tissue Engineering - Chitosan Based Hydrogels: Functions and Applications - page 443

Figure 9.33
SEM micrographs of the osteoblasts/scaffold construct. The osteoblasts were well attached to the pore wall, and
surrounded by an excreted interlaced fibrous network. (From Zhao, F. et al. 2002. Biomaterials 23: 3227-3234.
With permission.)
interactions between HA and COO − groups of collagen or gelatin. Moreover, the size of
HAp particles could be modulated via adjusting the polymer matrix. More gelatin or
collagen may result in the formation of small HAp particles [176]. This stable structure
endows the composite scaffold with excellent bioactivity.
9.5.5 Nerve
Nerve injuries are common in trauma surgery. Today, even under excellent conditions,
nerve regeneration can never achieve complete histological and clinical recovery. In the
peripheral nervous system, the proximal segment may be able to regenerate and reestab-
lish nerve function. However, the gap between the nerve stumps is too large (>2 mm), a
device is needed to bridge the gap in order to guide outgrowing nerve fibers and to pre-
vent the formation of neuroma. For the central nervous system, axons do not regenerate
appreciably in their native environment. The autologous nerve graft, although the gold
Figure 9.34
CT 3D reconstruction of repairing bone defect by chitosan-collagen-HA for 4 (a), 8 (b), and 12 (c) weeks. (d) The
bone defect site; (e) the newly formed bone in the bone defect site. (From Wang, Y. et al. 2008. J Biomed Mater Res
86A: 244-252. With permission.)