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Hyaluronic acid (HA) is one kind of polysaccharides composed of
repeat disaccharide units of N-acetylglucosamine and glucuronic acid
Commercial HA is commonly its sodium salt form. Sodium hyaluronate
is the key water maintaining substances in human skin. Bad living
environment and aging can cause the decrease of HA content in skin,
and as a result the water maintaining ability of the skin is
weakened and the akin looks dry and rough .One of the main causes of
skin senility is also the decrease of polysaccharides, such as HA.
The special structure characteristic of HA makes it has high
moisturizing and water content reguating function and its solution
has high viscoelasticity and lubricity. When HA solution is applied
on the surface of skin, it can form an air permeable layer and keep
the skin moist and smooth. Small molecular weight HA can penetrate
into dermis layer, fully combine with water, promote skin blood
microcirculation and nutrient absorption and maintain normal
metabolism, and as a result it plays a role of wrinkle removing,
look improving and health protecting.
Topical grade
HA can be used in many kinds of cosmetics, such as cream, milk,
water shampoo, lotion, etc. HA is one of the best natural
moisturzing components used in cosmetics.
Hyaluronic Acid with MSM is not just for arthritis patients, either.
Many are taking the supplements as a preventative measure.
Hyaluronic Acid lubricates not just the joints, but the whole body -
the eyes, the organs, tissues, and skin. It is often referred to as
"nature's moisturizer" and is found in many cosmetic creams.
Hyaluronic acid is known to reduce wrinkles. We advise taking
Vitamin C separately. HA works more effectively alone.Taking
Hyaluronic Acid with MSM and keeping an active lifestyle should help
prevent from arthritis symptoms.
About
Hyaluronic Acid:
Hyaluronic acid (HA, hyaluronan) is a special protein that exists
naturally in all living organisms. In the human body, it is found in
greatest concentrations in the synovial fluid of articular joints
for lubrication, the vitreous humor (fluid) of the eye, and most
abundantly in the skin. As we age, the body produces less Hyaluronic
Acid. The joints become stiff and the movement painful, the skin
becomes dry and wrinkly.
Hyaluronic acid exists naturally in all living organisms and is a
universal component of the spaces between the cells of body tissues
(extracellular space). It is a mucopolysacharide that has an
identical chemical structure whether it is found in simple bacteria
or in human beings.
HA is a double molecule, glucosamine combined with glucuronic acid.
Glucosamine is only one-half of the HA molecule, which is why
glucosamine yields results much slower and much less dramatic than
HA. Chondroitin raises the production of HA in the body, and thus
for those on large doses, there may be some of the same anti-ageing
benefits.
Hyaluronic Acid in the Skin:
In the skin, the extracellular matrix is composed of hyaluronic
acid and other sulfated GAGs, combined with collagen and elastin.
Large amounts of water are held in the ECM. When elastin is not
bathed in water, it becomes dry and brittle, thus the look of dry,
brittle, wrinkled skin.1
Half-life is defined as the time required for one half of the total
amount of a particular substance to be consumed, broken down, or
depleted. The half-life of hyaluronic acid in the cartilage is 2-3
weeks. But the half-life of hyaluronic acid in the skin is less
than 1 day! Hyaluronic acid is present in both the dermis and the
epidermis. 50% of the body’s naturally produced hyaluronic acid
that is found in the epidermis is metabolized and excreted in less
than 24 hours. Like hyaluronic acid produced in the body, hyleronic
acid taken as a nutritional supplement moisturizes from the dermis
to the epidermis - from deeper layers of the skin to the outer
layer.
The extracellular matrix fills up the space between the skin
cells. This makes the skin soft, smooth and elastic. But as we
age, hyaluronic content in the skin changes due to two separate
clinically proven factors.
1.
There is a decrease in synthesis of hyaluronic acid.
2.
Recompartmentalization – from the epidermis to the dermis.
Both changes leave
the epidermis depleted in hyaluronic acid resulting in thinning,
aging, and decreased moisture in the skin.
Hyaluronic
acid injection can be used to improve the skin's contour and reduce
depressions in the skin due to acne, scars, injury or lines.
Immediately or within a few hours after injection the site may be
red and swollen. This usually disappears within a week. Another one
or two treatments (at least a week apart) may be necessary to
achieve the desired correction. Hyaluronic acid implantation is not
permanent. Like natural hyaluronic acid, manufactured hyaluronic
acid once injected into the skin will gradually break down and be
absorbed by the body. In most cases, the hyaluronic acid
augmentation usually lasts between 6-9 months. Compared to collagen
implants hyaluronic acid appears to have a longer augmentation
effect, possibly lasting 2 to 3 times longer than the average
collagen implant. To maintain the initial results, repeat hyluronic
acid injections or top-up treatments will be necessary. Most people
following this protocol have 2 to 3 treatments per year.
Hyaluronic Acid is present in all living organisms. In your skin it
creates volume, resulting in a healthy and vital appearance.
Identified biochemically as a glycosaminoglycan (GAG), hyaluronic
acid was isolated about sixty years ago. Its name is derived from
the Greek word for glass (hyalos) which accurately describes its
transparent, glassy appearance.
The surface layers of the skin are supported from below by columns
of fibers made up mostly of collagen and elastin. This network of
fibers form the molecular sponge known as connective tissue. The
spaces within this sponge are filled with a composition of water,
protein complexes and hyaluronic acid. This jelly-like complex is
necessary for transportation of essential nutrients from the
bloodstream, via the capillary network, to the living cells of the
skin.
A Significant Innovation With Many Clinical Applications:
The dermal tissue contains collagen fibre bundles which support the
tissue and hyaluronic acid molecules that bind water and create
volume. Biodegradable. implants are usually composed of one of these
two components. Both can be extracted from animal tissues. Collagen
fibres are often extracted from bovine skin and hyaluronic acid
from rooster combs. The hyaluronic acid in Restylane, however, is
derived from a very defined non-animal source.
The interstitial volume is composed of water bound by hyaluronic
acid. Restylane is fully biodegradable and the metabolism turns it
into water and carbon dioxide. The metabolism of Restylane has two
phases. The first phase consists of slow, local degradation with a
half life of about a year. The second phase consists of quick
degradation in the blood with a half life of just a few minutes.
This means that the product has an extremely low systemic impact.
The normal daily metabolism of hyaluronic acid in man corresponds to
3 g, that is 200 Restylane 0.7 cc syringes.
Hyaluronic acid
plays a vital role in connective tissues such as the skin.
Approximately 56% of the hyaluronic acid concentration in the body
is found here. The elastic properties of hyaluronic acid offer
resistance to compression, so that the skin protects underlying
structures from damage. At the same time, the non-Newtonian
properties of hyaluronic acid allow the collagen fibres 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 the 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 hyaluronic acid decreases 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 ability of the skin to restore itself
is reduced. The reduction in volume then leads to wrinkles.
Structure
of Hyaluronic Acid:
Hyaluronic acid is a glycosaminoglycan (GAG). GAGs are giant
molecules (macromolecules) made up of repeating disaccharide units.
Although glycosaminoglycans are complex molecules in their own
right, individual GAGs can be used as building blocks in the
formation of larger, even more complex proteoglycan molecules. A
proteoglycan comprises a core protein with attached GAG side chains,
and almost any combination of protein and polysaccharide is
possible. However, many of the important biological proteoglycans
use hyaluronic acid as their backbone.
Molecular size:
The molecular length of hyaluronic acid varies between different
tissues and species. It may also vary depending on the condition of
the tissue. For example, the molecular size of hyaluronic acid in
synovial fluid is often lower than normal in joint diseases.
A hyaluronic acid molecule of 10,000 disaccharide units could extend
to 10 Mym if stretched out straight, a length approximately equal to
the diameter of a human red blood cell. This may not seem very
large, but in comparison with most chemical substances, it is a very
large molecule indeed.
Metabolism:
Hyaluronic acid is produced inside the cell membrane. The
metabolism of hyaluronic acid is very dynamic and synthesis is
usually balanced by catabolism. The catabolism or turnover of
hyaluronic acid is very fast compared to other biological molecules
(e.g. its half-life is less than one day in the skin).
Structure In The Solution:
The hyaluronic acid molecule is hydrophilic and attracts water
molecules. This means that hyaluronic acid is readily soluble in
water. In solution, the very long and thin hyaluronic acid chain
molecules kink and bend and adopt the shape of an expanded random
coil. These hyaluronic acid coils are so large that, even at a low
concentration of about 0.1% (1 mg/ml), the hyaluronic acid molecules
fill up the whole solution. At higher concentrations, the hyaluronic
acid coils intertwine and entangle, forming a flexible molecular
network of entangled molecules. This entangled network of hyaluronic
acid molecules is able to hold large amounts of water, while
permitting the passage of metabolites to and from the cells.
Water-binding Ability:
Proteoglycans containing hyaluronic acid are found in most of the
body's connective tissues (e.g. cartilage and the dermis of the
skin), one of their most important functions being to bind water and
thereby maintain a high level of hydration in the tissues. This
ability to bind water is provided by the hyaluronic acid component
of the proteoglycans, which can bind many times their own weight in
water.
The water-binding ability of hyaluronic acid stems from the unusual
three-dimensional structure of the hyaluronic acid molecule, which
(as previously described) occupies a very large volume in proportion
to its molecular weight. The presence of numerous small particles in
the spaces within the hyaluronic acid molecule draws water into the
molecule. As the spaces fill with water molecules, the hyaluronic
acid molecule is forced to expand and becomes fairly resistant to
compression. The longer the hyaluronic acid chain, the more water it
can hold.
Because the gel contains such large amounts of water, hyaluronic
acid can act as a medium through which diffusion can occur. In a
connective tissue without a blood supply of its own, such as
articular cartilage, hyaluronic acid is essential for the transport
of nutrients, gases and metabolites to and from the living cartilage
cells.
Viscoelastic Properties:
The ability of hyaluronic acid to bind water also gives it
viscoelastic properties. This means that it is compressible and will
return to its former shape once the compressing force is removed,
yet it can be poured like a liquid.
Structurally the scalp is identical to the skin tissue located
throughout the body except it also contains about 100,000 hair
follicles that give rise to hair. Actually the hair and the hair
follicle are a derivative of skin tissue. There are two distinctive
skin layers, one, the epidermis (outer layer) which gives rise to
the protective shield of the body and the other, the dermal layer
(deep layer) which makes up the bulk of the skin and is where the
hair follicle is located. This dermal layer is composed of
connective tissue and the connective tissue, with its gelatinous
fluid like characteristics provides support, nourishes and hydrates
the deep layers of the scalp. The result is healthy lustrous hair
and a moisturized scalp. Again, all of this is made possible because
of the presence of HA in the scalp tissue and its ability to form
this fluid and hold water.
Lips:
The lips are a core of skeletal muscle covered by skin tissue.
The dermal layer of the lips is composed primarily of connective
tissue and its components hyaluronic acid and collagen that give the
structure (shape) and plumpness to the lips. The hyaluronic acid
binds to water creating a gelatinous fluid that hydrates the
surrounding tissue and keeps the collagen (responsible for keeping
the skin tight) nourished and healthy. The result is healthy well
hydrated and plump lips that are well protected from the
environment.
Although Hyaluronic Acid (HA) can be found naturally in most every
cell in the body, it is found in the greatest concentrations in the
skin tissue. Almost 50% of the bodies HA is found here. It is found
in both the deep underlying dermal areas as well as the visible
epidermal top layers.
Young skin is smooth and elastic and contains large amounts of HA
that helps keep the skin stay young and healthy.
The HA provides continuous moisture to the skin by binding up to
1000 times its weight in water. With age, the ability of the skin to
produce HA decreases leaving the skin unhealthy and wrinkled.
The skin is the largest organ in the body comprising about 15% of
the body weight. Roughly 50% of the Hyaluronic Acid in our body is
found in the skin. Hyaluronic Acid and Collagen are vital to
maintaining the skin’s layers and structure. It is the collagen that
gives the skin its firmness but it is the HA that nourishes and
hydrates the collagen. Imagine the collagen as the stretchy fibers
that restore the skin back to shape when stretched. Collagen is like
a rubber band but stretch that rubber band a million times, like
what we do with our skin and without any moisture. Eventually that
rubber band gets overstretched (saggy) and dried out and will most
likely break. This is much the same way the collagen in our skin
reacts leaving our skin dry and wrinkled. Now imagine that same
rubber band stretched a million times while under water the whole
time. Chances of that rubber band drying out and breaking are
minimal. Consider the Hyaluronic Acid as the water that keeps the
collagen moist and elastic. Collagen is continuously surrounded and
nourished by the gelatinous HA substance. Young skin is smooth and
highly elastic because it contains high concentrations of Hyaluronic
Acid, which helps skin stay healthy. As we grow older, the body
loses its ability to maintain this same concentration in the skin.
With decreasing levels of HA in the skin, so goes the ability of the
skin to hold water. The result, the skin becomes drier and loses its
ability to restore itself. Hyaluronic acid acts as a space filler by
binding to water and thus keeping the skin wrinkle-free.
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玻尿酸.
