Case Study 2: Hyaluronic Acid
Outline
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Structure
Tissue and Cell distribution
Biological Function
Sources
Biomedical Applications
Structure & Function
HA is a non-sulphated GAG and is composed of
repeating polymeric disaccharides of D-glucuronic
acid and N-acetyl-D-glucosamine linked by a
glucuronidic β (1→3) bond.
• forms H-bonds with H2 O
molecules
• helps maintain hydration
of skin
Tissue and Cell distribution
In humans, HA is most abundant in the skin,
accounting for 50% of the total body HA, the vitreous
of the eye, the umbilical cord, and synovial fluid, but it
is also present in all tissues and fluids of the body, such
as skeletal tissues, heart valves, the lung, the aorta, the
prostate, tunica albuginea, corpora cavernosa and
corpus spongiosum of the penis.
Biological Function
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hydration, lubrication of joints, a space filling capacity, and
the framework through which cells migrate
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regulates several aspects of tissue repair, including activation
of inflammatory cells to enhance immune response and the
response to injury of fibroblasts and epithelial cells.
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provides the framework for blood vessel formation and
fibroblast migration, that may be involved in tumor
progression.
Sources
Biomedical Applications
Biomedical Applications
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In tissue engineering. Chemical crosslinking of HA combines
desirable biological and mechanical properties, even for
bone or cartilage tissue engineering. Moreover, crosslinking
extends the HA degradation process in vivo and provides
long-term stability. Crosslinking HA at various densities has
been used for multiple applications including orthopedics,
cardiovascular medicine, and dermatology.
Biomedical Applications

As a dermal filler. To address age-related changes in skin
quality and appearance, several treatments have been
proposed. They may be classified based on their composition
with primary ingredients such as collagen (bovine, porcine, or
human), animal or synthetic hyaluronic acid, poly-L-lactic
acid, calcium hydroxyapatite, polymethyl methacrylate, and
polyacrylamide gel.
Biomedical Applications

HA as dermal filler and some of the commercially available
products
Material
Hyaluronic acid
Brand name
Description
Duration
Restylene®
Crosslinked HA
(20 mg/mL)
Temporary 6–12
months
Prelane®
Crosslinked HA
(20 mg/mL)
Temporary 6–12
months
Juvéderm™
Crosslinked HA
(24 mg/mL)
Temporary up
to 12 months
Elevess®
Crosslinked HA
(28 mg/mL)
Temporary
months
Hylaform®
Crosslinked HA
(5 mg/mL)
Temporary 3–6
months
Biodegradability
Biodegradable
Biomedical Applications

In osteoarthritis treatment. After damage or aging, synovial
fluid cannot provide the required viscoelastic response to
compression and tangential forces arising in everyday life,
allowing cartilage-cartilage contact and increasing wear of
the joint surface. Intra-articular treatment with HA and hylans
(uncrosslinked HA and crosslinked HA, respectively) has
recently been accepted as a common therapy for reducing
pain associated with OA. Currently, products such as
Hyalgan® (HA), Orthovisc® (HA) and Synvisc® (hylan GF 20)
are available as viscosupplements for intra-synovial injection
in osteoarthritis treatment
References

Fakhari, A. & Berkland, C. (2013). Applications and Emerging Trends of Hyaluronic Acid in Tissue
Engineering, as a Dermal Filler, and in Osteoarthritis Treatment. Acta Biomater. 2013 Jul; 9(7):
7081–7092. <10.1016/j.actbio.2013.03.005>

Papakonstantinou, E., Roth, M. & Karakiulakis, G. (2012). Hyaluronic acid: A key molecule in skin
aging. Dermato-Endocrinology 4:3, 253–258; July–December 2012; © 2012 Landes Bioscience.
<http://dx.doi.org/10.4161/derm.21923>