Dynamic surface tension parameters of protein–lipid–salt solutions as a system simulating blood plasma

Abstract

Measurements of the dynamic surface tension (DST) of liquids is one of the simplest and fastest methods for the analysis of various chemical solutions and biological liquids. Solutions of the three-component systems on the basis of bovine serum albumin (BSA), natural phosphatidylcholine (PC), and sodium chloride are investigated. It is found that the salt content (especially at high concentrations) exerts a major impact during short time periods (0.1–1.0 s); and the BSA concentration, in intermediate and long time periods (over 1.0 s); however, changes in the PC concentration (in the range of concentrations typical for blood) insignificantly affect most of the DST parameters. The changes (by 22–68%) of the tensiogram slope values, λ₀, λ₁, and λ₂, are most informative among the seven studied DST parameters. This has allowed us to determine the optimal concentrations ranges for BSA (60–80 g/L), PC (1–4 mM), and NaCl (130–150 mM) in the mixture, which correspond to their content in the blood plasma of humans and animals. For four parameters, σ₁…σ₄, only small correlations with changes in the proportion of the three components in the mixture are found. The obtained relationships are important for both supplementing fundamental databases and prognostic modeling in biology and medicine.