Hyaluronan(HA) was first purified from the vitreous humor of bovine eyes by Karl Meyer in 1934 [1]. He named the molecule “hyaluronic acid” because of the hyaloid appearance of the substance when swollen in water and the probable presence of hexuronic acid as one of the components. In the 1950s, Meyer and colleagues determined that HA was a linear polysaccharide composed of repeating β-1,4-linked d-glucuronic acid (GlcA) and β-1,3-linked N-acetyl-d-glucosamine (GlcNAc) disaccharide units ( Fig. 1A) [2]. The various names of HA reflect the properties of the molecule under various conditions. When first isolated, HA behaved like a mild acid; therefore, Meyer named it “hyaluronic acid” [1]. Under physiological conditions, HA exists as a polyelectrolyte with associated cations, frequently as a sodium salt; therefore, the name sodium hyaluronate. The name was later amended to “hyaluronate” in reference to its salt form or “hyaluronan,” a term used to encompass all forms of the molecule