Hyaluronic acid, or hyaluronan, is a water soluble, anionic extracellular matrix glycosaminoglycan polymer with variable molecular weight that determines its physiological role, rheological properties and applications. Since its discovery in the early 1930s, there has been an increased awareness concerning the biology of hyaluronic acid, its signaling pathways and its role in the biomedical and cosmeceutical industry. Being an endogenous molecule, hyaluronic acid is biocompatible, biodegradable, and has strong mucoadhesive, viscoelastic properties. The authors provide chemical modification approaches to hyaluronic acid, as well as address the magnitude of applications of hyaluronic acid-based targeted drug vectors and patents. The closing study discusses glycosaminoglycans, a specialized group of unbranched, anionic disaccharide polymers attached by a covalent linkage to the membrane proteins via sulphate groups in their sugar moieties.