ABSTRACT

In 1934, Meyer and Palmer reported their chemical analysis of bovine vitreous humor and identi cation of its principal compound, an acidic mucopolysaccharide they named hyaluronic acid (Meyer and Palmer 1934). By 1986, it was clear this mucopolysaccharide is synthesized by mammalian cells and certain species of bacteria as a salt (not an acid), rendering the original moniker something of a misnomer. Growing recognition of this compound’s biological properties, together with increasing commercial applications in ophthalmologic and cosmetic formulations, prompted Balazs, Laurent, and Jeanloz (1986) to change the name of this mucopolysaccharide from hyaluronic acid (or “hyaluronate”) to hyaluronan. At the same time, the acronym commonly used for the original name, HA, began to generate confusion in the nascent eld of tissue engineering due to widespread use of

19.1 Prologue: What’s in a Name? ................................................................................................ 331 19.2 Introduction .......................................................................................................................... 332 19.3 Receptor-Mediated Biological Functions ............................................................................. 333

19.3.1 Hyaluronan Contribution to Receptor Binding......................................................... 333 19.3.2 Receptor Contribution to Binding with Hyaluronan ................................................ 334

19.4 Speci c Hyaluronan Biological Functions Mediated by CD44 and RHAMM .................... 336 19.4.1 Cell Motility Chemotaxis, Cell-Cell-Extracellular Matrix Attachment, and

In Vivo Extracellular Matrix Metabolism (Hyaluronan Endocytosis) ...................... 336 19.4.1.1 Basics of Cell Motility ............................................................................... 338 19.4.1.2 Speci cs of Hyaluronan/CD44 Cell Motility Mechanisms ....................... 338 19.4.1.3 Chemotaxic Attraction to Hyaluronan ....................................................... 338 19.4.1.4 Cell Attachment and Migration ................................................................. 339 19.4.1.5 Cell-Extracellular Matrix Proteolysis ........................................................340 19.4.1.6 Endocytosis ................................................................................................340