Hyaluronic acid of human skin and post-burn scar: heterogeneity in primary structure and molecular weight.

Hyaluronic acid (HA) was isolated from the dermis and epidermis of normal human skin and from normal and hypertrophic scar tissue, and the molecular properties of this polysaccharide were studied by circular dichroism (CD) and high performance liquid chromatography. The molecular weights of HA of normal skin and post-burn scar tissue range from 62,000 to 180,000. Hexosamine analysis showed no galactosamine contamination and 0.37 to 2.2 w/w% of protein in the HA sample. Uronic acid analysis suggests a heterogeneous distribution of glucuronic and iduronic acids. The CD profiles of these samples are similar, indicating no significant conformational variations among them. These data suggest that the variation in the molecular properties of HA between skin and scar tissue may be due to diversity of embryonic origin between epidermis HA and dermis HA, and to the diversity of the wound-healing process between normal scar HA and hypertrophic scar HA.