hyaluronate

Hyaluronate, the salt form of hyaluronic acid, is a glycosaminoglycan (GAG) distributed widely in connective, epithelial, and neural tissues. It is a linear, non-sulfated polymer composed of repeating disaccharide units of D-glucuronic acid and N-acetyl-D-glucosamine, linked by alternating β-1,4 and β-1,3 glycosidic bonds. In physiological conditions, the carboxyl groups are deprotonated, giving the molecule a high negative charge and strong water-binding capacity, yielding highly hydrated viscous solutions and gels.

Hyaluronate is synthesized at the inner surface of the plasma membrane by hyaluronan synthases HAS1–HAS3 and extruded directly into the extracellular matrix. It is rapidly turned over by hyaluronidases and other clearance pathways; in skin and synovial fluid, half-lives are on the order of hours to days depending on tissue.

Natural function includes hydration and turgor of the extracellular matrix, lubrication of joints, and influence on cell adhesion, migration, proliferation, and differentiation. Receptors such as CD44 and RHAMM mediate signaling linked to development, wound healing, inflammation, and cancer progression.

Hyaluronate commonly exists as salts, notably sodium hyaluronate and potassium hyaluronate, which are used commercially. It is obtained commercially by bacterial fermentation or extraction from animal tissues, followed by purification and, in some applications, chemical modification or cross-linking.

Medical and cosmetic applications include viscosupplementation for osteoarthritis, dermal fillers, and ophthalmic viscoelastic agents. Side effects are generally uncommon but may include local inflammatory or allergic reactions or contamination risks.