Biology Reference
In-Depth Information
Thermoresponsive chitosan/glycerophosphate salt hydrogel coated with
poly-
D
-lysine immobilized via azidoaniline photocoupling improves cell
adhesion and morphology and neurite outgrowth compared with uncoated
chitosan/glycerophosphate salt hydrogel (
Crompton et al., 2007
). Increasing
poly-
D
-lysine concentration did not alter cell survival but significantly
inhibited neurite outgrowth (
Crompton et al., 2007
).
Laminin is an 180-KDa glycoprotein that plays an important role in neuro-
nal cell adhesion, differentiation, and neurite outgrowth (
Madison, da Silva,
Dikkes, Sidman, & Chiu, 1987; Manthorpe et al., 1983
). Two peptides of
the lamin-1 molecule, namely, YIGSR (Tyr-Ile-Gly-Ser-Arg) and IKVAV
(Ile-Lys-Val-Ala-Val) sequences, mediate receptor-specific neural cell
adhesion and are known to promote cell adhesion and neurite outgrowth,
respectively (
Graf et al., 1987; Kleinman et al., 1988; Pierschbacher &
Ruoslahti, 1984; Sephel, Burrous, & Kleinman, 1989; Tashiro et al., 1989
).
Moreover, these domains enhance SC migration. Surface modification of a
biomaterial may improve its biocompatibility. Matsuda et al. developed a
new biomaterial consisting of molecularly aligned chitosan with IKVAV and
YIGSRpeptides bonded covalently. Briefly, chitosanwas thiolated by reacting
4-thiobutyrolactonewith the chitosan amino group and thiol groupof cysteine
located at the endof the synthetic laminin peptides thatwere reactedchemically
with thiolated chitosan to form chitosan-
S
-
S
-laminin peptide (
Matsuda,
Kobayashi, Itoh, Kataoka, & Tanaka, 2005
).
A novel chitosan gel has been synthesized by reaction of chitosan amine
group with methacrylic anhydride, resulting in methacrylamide chitosan
(
Yu, Kazazian, & Shoichet, 2007
). Maleimide-terminated cell adhesive pep-
tides, mi-GDPGYIGSR and mi-GQASSIKVAV, have been coupled to a
thiolated form of methacrylamide chitosan, resulting in increased neuronal
adhesion and neurite outgrowth (
Yu et al., 2007
).
Synthetic surface modification methods often lead to alterations of the
original material's physical proprieties. The plasma surface modification pro-
cess has been shown to be able tomodify the surface properties of a biomaterial
without affecting its bulk physical properties (
Yeh, Iriyama, Matsuzawa,
Hanson, & Yasuda, 1988
). Compared with the conventional chemical
method, the percentage of laminin incorporated on chitosan films by plasma
treatment is significantly higher (
Huang, Huang, Huang, & Chen, 2007
).
Moreover, laminin-modified chitosan membrane significantly increases SC
adhesion (
Huang et al., 2007
). Carbon nanotube/chitosan fibers coated with
laminin, via an oxygen plasma technique, allowed PC12 cell adhesion,
growth, and guided oriented neurite outgrowth (
Huang et al., 2011
).