Biology Reference
In-Depth Information
In another study, a laminin-coated conduit was shown to enable axons to
cross the lesioned area of the spinal cord and to reduce glial scar formation
(
Cheng et al., 2007
). Behavioral analyses evaluating the Basso-Beattie-
Breshnahan motor behavior score, the sensorimotor combined behavior
score, open-field walking scores, and treadmill analyses demonstrated that
following the implantation of the laminin-coated nerve conduit the rats
showed a tendency toward behavior improvement and functional recovery
(
Cheng et al., 2007
). Histological and immunocytochemical analyses indi-
cated that the implanted nerve conduit groups were capable of leading the
damaged axons through the lesioned area without triggering inflammation
or apoptosis (
Cheng et al., 2007
).
Other cell adhesion molecules, such as L1, have been shown to enhance
CNS regeneration, and Xu et al., by using the optic nerve transection animal
model, showed that polyglycolic acid (PGA)-chitosan conduits coated with
recombinant L1-Fc have a potential role in promoting nerve regeneration
by guiding axonal regrowth and remyelination (
Xu et al., 2004
).
3.2. Chitosan conduits combined with cells for CNS repair
NSPCs, bone marrow mesnchymal stem cells (BMSCs), and radial glial cells
have been used in combination with chitosan for SCI repair (
Table 1.3
).
Results showed that, compared to direct NSPCs injection, chitosan channels
improved their survival after implantation (
Bozkurt et al., 2010; Guo et al.,
2012; Kim et al., 2011
). In other studies, NSPCs isolated from the
subependyma of lateral ventricles of adult green fluorescent protein (GFP)
transgenic rat forebrains (
Zahir et al., 2008
) or derived from brain or spinal
cord of transgenic GFP rats (
Nomura, Zahir, et al., 2008
) in combination with
chitosan channels were implanted into the spinal cord after transection injury.
These
in vivo
studies showed excellent survival of NSPCs as well as differen-
tiation into astrocytes and oligodendrocytes (
Nomura,Zahir,etal.,2008;
Zahir et al., 2008
). Moreover, host neurons were identified in the tissue bridge
that formed within the chitosan tubes and bridged the transected cord stumps
(
Zahir et al., 2008
). The excellent
in vivo
survival of the NSPCs coupled with
their differentiation and maintenance of host neurons in the regenerated tissue
bridge demonstrates that the use of three-dimensional chitosan scaffolds com-
bined with adult spinal cord-derived NSPCs is a promising therapeutic strat-
egy for stem cell delivery and enhances regenerative potential restoring spinal
cord function after SCI although functional outcome recovery remains poor
(
Bozkurt et al., 2010; Nomura, Zahir, et al., 2008; Zahir et al., 2008
).
