Hyaluronic acid is an abundant extracellular matrix glycosaminoglycan in skin and mesenchymal tissues, where it facilitates cell migration during wound healing, inflammation, and embryonic morphogenesis.

HA is a polysaccharide of the glycosaminoglycans (GAG) family found in the extracellular matrix (ECM) of many tissues. HA is a huge molecule that consists of many repeats of a simple disaccharide stretched end-to-end. HA binds a large amount of water, forming a viscous hydrated gel that gives connective tissue the ability to resist compression forces.

HA helps provide resilience and lubrication to many types of connective tissue, notably for the cartilage in joints. HA is also found in the matrix of migrating and proliferating cells, where it inhibits cell-to-cell adhesion and facilitates cell motility.

CD44 a surface glycoprotein expressed by leukocytes, binds HA. Through such binding, T cells may be retained in tissues and remain bound to endothelium at sites of inflammation.

See also

 glycosaminoglycans (GAG)
 extracellular matrix (ECM)

References

 Toole BP. Hyaluronan: from extracellular glue to pericellular cue. Nat Rev Cancer. 2004 Jul;4(7):528-39. PMID: #15229478#