Biomedical Engineering Reference
In-Depth Information
carboxylic groups of unmodified hyaluronan molecules with the
hydroxyl groups on the other hyalunonic acid has been performed
to fabricate the sponge form. And then, bone marrow-derived mes-
enchymal progenitor cells were seeded to induce chondrogenesis
and osteogenesis on this scaffold, resulting in successfully sup-
ported mesenchymal stem cell proliferation and differentiation for
osteochondral application. Also, sulfation reaction onto hyaluronan
gel has been investigated to create a variety of sulfated derivates
ranging from one to four sulfate groups per disaccharide subunit.
A cross-linking network, hydrogel, can be formed using diamines
of individual hyaluronic acid chains together. Chondrocytes were
seededontosulfatedhyaluronicacidhydrogelandshowedgoodcell
compatibility for the tissue-engineered cartilage.
1.2.4.7 Chitosan
Chitosan,apolysaccharidederivedfromchitin,iscomposedofasim-
ple glucosamine monomer and is similar in physicochemical prop-
erties to many glycosaminoglycans. It has been widely recognized
thatitisrelativelybiocompatibleandbiodegradable,doesnotevoke
a strong immune response, and is relatively cheap due to its abun-
danceandgoodreactivitywithdiversemethodsofchemicalprocess-
ing. Chitin is typically extracted from arthropod shells by means
of acid/alkali treatment to hydrolyze acetamido groups from N-
acetylglucosamine, resulting in the production of chitosan. It has a
molecular weight of 800,000
∼
1,500,000 g/mole and dissolves eas-
ilycomparedwithnativechitinpolymer.
1
,
5
,
7
,
20
Fortheapplicationof
thetissue-engineeredcartilage,a3Dcomposite,suchaschondroitin
sulfate A/chitosan hydrogel scaffold, was prepared. This hydrogel
supported the differentiated phenotype of seeded articular chon-
drocytesandtypeIIcollagenandproteoglycanproduction.Also,the
organic/inorganic hybrid scaffold as the chitosan/tricalcium phos-
phate scaffold was fabricated for tissue-engineered bone. When
osteoblastic cells collected from rat fetal calvary was seeded
onto a chitosan/tricalcium phosphate scaffold, the cells prolif-
erated in a multiplayer manner and deposited a mineralized
matrix.
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