What is Hyaluronic Acid?
Hyaluronic Acid (sodium hyaluronate, hyaluronan, HA)
is a fluid that exists in every single living organism.
It is "nature's moisturizer" in that it keeps the entire body
moisturized. In humans, the greatest amounts of hyaluronic acid are
found in the joint areas. It is responsible for lubricating the
cartilage in the joint areas. The cartilage keeps the bones from
rubbing together. With hyaluronic acid, our joints have the
mobility to bend with ease. Hyaluronic acid also aids in
lubrication of the eyes.
What is the History of Hyaluronic Acid?
In 1934, Karl Meyer and his colleague John Palmer isolated a
previously unknown chemical substance from the vitreous body of
cows’ eyes. They found that the substance contained two sugar
molecules, one of which was uronic acid. As a result, they proposed
“for convenience, the name ‘hyaluronic acid’, from hyaloid
(vitreous) + uronic acid.” At the time, they did not know that the
substance which they had discovered would prove to be one of the
most interesting and useful natural macromolecules.
Hyaluronic
acid (HA) was first used commercially in 1942 when Endre Balazs
applied for a patent to use it as a substitute for egg white in
bakery products. He went on to become the leading expert on
Hyaluronic Acid, and made the majority of discoveries concerning
Hyaluronic Acid during the next 50 years.
Where is Hyaluronic Acid in the body?
The upper layers of skin are supported by two major columns made up
of collagen and Elastin. These two substances make up connective
tissue, and the spaces created are filled with a combination of
Hyaluronic Acid, water, and protein complexes. This area is
normally used for the transportation of essential nutrients from
the bloodstream to the skin.
Hyaluronic Acid is found in great quantities in young skin and the
synovial fluids of both humans and animals. Unfortunately
pollutants and sunlight break down the Hyaluronic acid over time by
creating oxy radicals. Studies say that by the age of 50 you will
have approximately half the Hyaluronic Acid of childhood.
Hyaluronic Acid in the body?
Hyaluronic acid exists naturally in all living
organisms and is a universal component of the spaces between the cells
of body tissues (extra cellular space). It is a polysaccharide that has
an identical chemical structure whether it is found in simple bacteria
or in human beings. HA can be found in many places in the human body,
including:
- Skin - where it creates volume (without
hyaluronic acid, the skin would appear dry, withered and wrinkled)
- The Vitreous Body - where it gives volume
and shape to the eyes.
-
Cartilage, Bone and Synovial
Fluid - where it acts as a lubricant, shock absorber and
filter, amongst other things.
-
Blood Vessels
-
The Umbilical Cord -
where its function is to ensure that the contact between the mother
and the fetus is never broken.
Hyaluronic acid and skin?
Hyaluronic acid plays a vital role in connective tissues such as the skin. The
dermis of the skin comprises a network of collagen fibers within an
interstitial substance composed largely of hyaluronic acid. The
elastic properties of hyaluronic acid offer resistance to compression,
so that the skin protects underlying structures against damage. At the
same time, the non-Newtonian properties of hyaluronic acid allow the
collagen fibers to move easily through the interstitial substance.
This lubrication by hyaluronic acid allows the skin to accommodate the
changes in shape and volume that occur when the underlying bones and
joints move.
The hyaluronic acid gel in the skin also inhibits movement of foreign
particles, such as bacteria. This makes an important contribution to
the skin’s defensive function as a barrier to infection. The barrier
also affects the free passage of other exogenous material, such as
some drugs. This is the reason why some subcutaneous injections and
drugs in creams or ointments include a small amount of the enzyme
hyaluronidase. The enzyme degrades the hyaluronic acid gel around it,
so that the drug is able to pass more freely through the tissues of
the skin.
When we get older, the amount of
hyaluronic acid in the skin diminishes as the skin cells lose their
ability to produce hyaluronic acid. In addition, the molecular weight
of the HA is decreased with age, so that it does not hold water as
well as before. This can be demonstrated by squeezing the skin between
the fingers. In young people, the skin rapidly restores itself to its
original volume. However, as we get older, the skin’s ability to
restore itself is reduced.
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