Hyaluronic Acid-based Scaffolds for Brain Tissue Engineering - Hyaluronic Acid for Biomedical and Pharmaceutical Applications - page 126

studied to evaluate their abilities to induce neural regeneration in vivo .
Stem/progenitor cells can be collected from many tissues including
the brain, spinal cord, olfactory system, bone marrow or blood.
Each of these cell populations can be propagated in cell culture and
transplanted into the injured area to produce functional factors, or
differentiated into specific cells.
6.4 Research using Hyaluronic Acid-based Scaffolds
for Brain Regeneration
HA is a popular material for brain tissue regeneration because it is
normally present in high levels in the ECM of connective, epithelial
and neural tissues [31, 32]. HA is known to play roles in cellular
processes like cell proliferation, morphogenesis, inflammation, and
wound repair [33]. It has also been reported that HA scaffolds
could reduce glial scar formation after implantation [34]. The recent
progress on HA-based scaffolds for brain regeneration is briefly
summarised in the following section.
6.4.1 Modification of Hyaluronic Acid-based Scaffolds for
Brain Regeneration
HA possesses excellent biodegradability and biocompatibility
and therefore has been widely applied as a biomaterial for drug
delivery, tissue engineering and regenerative medicine. However,
its extreme hydrophilicity and limited bioactivity preclude many
direct applications in the biomedical field. Therefore, many chemical
modification strategies including crosslinking and conjugation have
been developed to obtain insoluble HA hydrogels with optimised
mechanical, chemical, and biological properties. Among the
modification strategies, the carboxyl and hydroxyl groups are two
principal targeting sites for synthesising diverse HA derivatives,
e.g., amidated HA, esterified HA, and etherified HA. Further
crosslinking reactions between HA or HA derivatives can be achieved