Hyaluronan and the process of aging in skin

Abstract

The process of aging of human skin is not well understood. However, loss of apparent moisture is one of the hallmarks of aging skin, with its attendant wrinkling and deterioration in appearance. Hyaluronan (HA, hyaluronic acid) is the predominant mechanism for skin moisture, and must be involved in the aging process. Hyaluronan has an enormous volume of associated water-of-hydration. The water that surrounds the HA molecule is not in equilibrium with the remaining water of the body, but comprises its own compartment. A 70 kg individual has 15 g of HA, half of which is contained in skin. There is also rapid turnover of HA, with a half-life in skin of 1-2 days [1, 2]. However, the biology of skin HA and its bound water has never been thoroughly studied as a function of age. Understanding the metabolism of HA, its reactions within skin, and the interactions of HA with other skin components will facilitate understanding of skin aging as well as decrease in skin hydration. © Springer-Verlag Berlin Heidelberg 2010.