What is Sodium Hyaluronate? A Comprehensive Guide to its Structure and Function

Sodium hyaluronate is the sodium salt of hyaluronic acid, widely found in human connective tissue, skin, synovial fluid, and eye tissue. Hyaluronic acid was first discovered in 1934 by American scientist Karl Meyer in the vitreous humor of bovine eyes. Due to its excellent water retention and biocompatibility, sodium hyaluronate is widely used in medicine, aesthetic medicine, and cosmetics.

Structurally, sodium hyaluronate is a linear high-molecular-weight polysaccharide composed of D-glucuronic acid and N-acetylglucosamine linked alternately by β-1,3 and β-1,4 glycosidic bonds. Its long-chain molecular structure allows it to form a three-dimensional network in water. This structure gives it extremely strong hydrophilicity; one gram of sodium hyaluronate can theoretically bind hundreds or even thousands of times its own weight in water, thus demonstrating outstanding moisturizing properties.

Based on molecular weight, sodium hyaluronate can be classified into high-molecular-weight, medium-molecular-weight, and low-molecular-weight types. High-molecular-weight sodium hyaluronate primarily forms a protective film on the skin surface, reducing moisture loss; low-molecular-weight sodium hyaluronate penetrates more easily into the stratum corneum, hydrating and conditioning the skin barrier. In the medical field, sodium hyaluronate can also be cross-linked to create fillers for soft tissue filling and shaping.

In the human body, sodium hyaluronate performs multiple physiological functions. First, it is an important component of the extracellular matrix, helping to maintain tissue stability. Second, in joints, sodium hyaluronate is a key component of synovial fluid, providing lubrication and cushioning to reduce joint friction. In ophthalmology, sodium hyaluronate is commonly used in artificial tears or surgical aids to maintain ocular surface moisture and protect tissues.

Sodium hyaluronate is a naturally occurring high-molecular-weight substance derived from the human body, with a well-defined structure and diverse functions. Its excellent safety profile and wide applicability make it an important basic raw material in the pharmaceutical and skincare fields.