What is a Hyaluronan?
Hyaluronic acid (abbreviated most commonly as HA, sometimes as HY) is a carbohydrate, more specifically a simple glycosaminoglycan (a class of negatively charged polysaccharides) that provides compression strength, lubrication and hydration within the extracellular matrix (ECM) – the tissue that provides structural support to cells. It also regulates cell adhesion and motility and mediates cell proliferation and differentiation making it not only a structural component of tissues, but also an active signalling molecule.
Hyaluronan refers to all physiological forms of HA, the most common of which is the sodium salt. Hyaluronan is a scaffold secreted by cells that surrounds them in vivo.
HA can be several thousands of sugars (carbohydrates) long. When not bound to other molecules, it binds to water giving it a stiff viscous quality like jelly. This viscous gel is one of the most heavily researched substances in medicine today with thousands of trials mostly in the fields of orthopaedics and eye surgery. Its function in the body is, amongst other things, to bind water and to lubricate movable parts of the body, such as joints and muscles. Its consistency and tissue friendliness allows it to be beneficial in skin-care products as an excellent moisturizer. Because HA is one of the most hydrophilic (water-loving) molecules in nature, one molecule can bind to 400 water molecules, with numerous benefits for the human body it can be described as “nature’s moisturizer.
What is Hyaluronic Acid’s Chemical Structure?
HA, C28H44N2O23, is chemically classified as a glycosaminoglycan and presents as a large high molecular weight molecule. The molecule is made up of a repetitive sequence of two modified simple sugars, one called glucuronic acid and the other N acetyl glucosamine. These compounds are both negatively charged and when put together, they repel, producing an exceptionally long stretched out molecule. HA molecules, which are long and large, produce a high viscosity (lubrication) effect which resists compression and allows our joints and skin to bear weight.
When was Hyaluronic Acid discovered?
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. Its discovery was very unique. No other molecule had ever been discovered that has such unique properties to the human body. Balazs went on to become the leading expert on HA, and made most of discoveries concerning hyaluronic acid benefits.
Is Hyaluronic Acid Natural?
HA is a natural glycosaminoglycan (polysaccharides that are an important component of connective tissue) and can be derived from multiple resources, foods, supplements and HA powders. HA is distributed widely throughout connective, neural, and epithelial tissue. It is one of the chief components of the extracellular matrix. In short, HA supports many important areas of the body, with notable benefit to joints and skin. So, the answer is, yes, hyaluronic acid is completely natural.
Where is Hyaluronic Acid located in the body?
HA is found naturally in most every cell in the body and occurs in high concentrations in the connective, epithelial, and neural tissues. In each body location, it serves a different function. Unfortunately, HA also has a half-life (the time it takes for the molecule to get broken down and excreted from the body) of less than 3 days and possibly even as little as one day in the skin. For this reason, it is imperative that the body continually replenish itself with HA. Unfortunately, as we age, we lose the ability to replace HA at the rate required which in part explains why age related symptoms appear.
The extracellular matrix (ECM) is a gelatinous (gel-like) fluid that surrounds almost all living cells and is essential to life. It gives structure and support to the body and without it, we would just be a trillion cells without a shape or function. It is essentially the mortar between the bricks. The skin, bones, cartilage, tendons and ligaments are examples where the ECM is located in the body. The ECM is composed of material (fibrous elements) called elastin and collagen surrounded by a gelatinous substance (Hyaluronic Acid). HA’s roles in the ECM is to help the stretchy fibres in the body from overstretching and drying out by continually bathing them in this nutritious water base gelatinous fluid. It also serves as a wonderful medium through which nutrients and waste are transported to and from the cells of these structures. This fluid would not exist if it was not for the ability of the HA molecule to bind up to 1000 times its weight in water.
Hyaluronic Acid in Skin
The skin is the largest organ in the body comprising about 15% of the body weight. Roughly 50% of the HA in our body is found in the skin. HA 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 fibres that restore the skin back to shape when stretched. Collagen is like a rubber band but stretch that rubber band a million times, as we do with our skin, without any moisture and 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 in need of moisture. 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 HA 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 HA, 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 maintain its hydration.
The surface layers of the skin are supported from below by columns made up mostly of collagen and elastin. This fibrous network forms a ‘molecular sponge’ known as connective tissue and comprises water, protein complexes (e.g. collagen) and HA. This jelly-like complex transports essential nutrients from the blood stream via the capillaries in your skin. HA also acts as a space filler by binding to water and thus keeping the skin wrinkle-free.
HA contributes to skin’s barrier function, slowing down transepidermal water loss (TEWL). HA is utterly hydrophilic (water loving): one molecule can bind to 400 water molecules making its anti-TEWL, hydration and plumping effects truly remarkable.
Hyaluronic Acid in 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 HA and collagen that give the structure (shape) to the lips. The HA 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.
Hyaluronic Acid in Eyes
HA is highly concentrated inside the eyeball. The fluid inside the eye called the vitreous humor is composed almost completely of HA which gives the fluid inside the eye a viscous gel like property. This gel acts as a shock absorber for the eye and serves to transport nutrients into the eye.
Hyaluronic Acid in Scalp Tissue and Hair Follicles
Structurally the scalp is identical to the skin tissue except it also contains about 100,000 hair follicles that give rise to hair. 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.
Hyaluronic Acid in Bones and Cartilage
HA is found in all bones and cartilage structures throughout the body; both structures provide a resilient rigidity to the human body. HA is especially found in various forms of cartilage but none more than the hyaline cartilage. As you’ve probably guessed, hyaline is short for hyaluronic acid. Hyaline cartilage covers the ends of the long bones where articulation (bending) occurs and provides a cushioning effect for the bones. The hyaline cartilage has been called the “gristle cartilage” because its resistance to wear and tear. Hyaline cartilage also supports the tip of the nose, connects the ribs to the sternum and forms most of the larynx and supporting cartilage of the trachea and bronchial tubes in the lungs.
Hyaluronic Acid in Synovial Fluid
Our joints (like the elbows and knees) are surrounded by a membrane called the synovial membrane which forms a capsule around the ends of the two articulating bones. This membrane secretes a liquid called the synovial fluid. Synovial fluid is a viscous fluid with the consistency of motor oil. It has many functions, but none more than providing the elastic shock absorbing properties of the joint. Its second most important function in the joint is to carry nutrients to the cartilage and to also remove waste from the joint capsule.
Hyaluronic Acid in Tendons and Ligaments
Connective tissue is found everywhere in the body. It does much more than connect body parts; it has many forms and functions. Its major functions include binding, support, protection, and insulation. One such example of connective tissue is the cordlike structures that connect muscle to bone (tendons) and bone to bone (ligaments). In all connective tissue there are three structural elements; they are: ground substance (HA), stretchy fibres (collagen and elastin), and a fundamental cell type. Whereas all other primary tissues in the body are composed mainly of living cells, connective tissues are composed largely of a non-living ground substance the hyaluronic acid, which separates and cushions the living cells of the connective tissue. The separation and cushioning allow the tissue to bear weight, withstand great tension and endure abuse that no other body tissue could. All of this is made possible because of the presence of the HA and its ability to form the gelatinous ground substance fluid.