Contrasting effects of albumin and hydroxyethyl starch solutions on physical properties of sodium hyaluronate solution.

Hydroxyethyl starch (HES) solution reportedly sheds the endothelial surface layer (ESL) consisting of polysaccharide glycosaminoglycans, whereas albumin stabilizes the ESL. Here we compared the effects of albumin and HES (MW 130,000) solutions on the physical properties of sodium hyaluronate (NaHA, MW 1.3 × 106 ) solution, a constituent of the ESL. Partial specific volumes (v) and intrinsic viscosities ([η]) of NaHA in 0.15 M NaCl solution containing albumin or HES (1-3%) were calculated from densities and viscosities extrapolated at infinite dilutions. Flow activation energy (E) of 0.2% NaHA in phosphate-buffered saline containing albumin or HES was obtained from the temperature-dependence of viscosities. A 3% albumin solution decreased v of NaHA by 3% compared to HES. A 3% HES solution, but not albumin, decreased [η] of NaHA by 34%, and decreased E values by 11% compared to albumin. These findings suggest that HES locally restricts NaHA dispersion, whereas albumin contracts NaHA structure.