A Set of Fluorescent Probes to Study the Influence of Low Molecular Weight Cryoprotectants on Human Erythrocyte Membranes

Abstract

A set of fluorescent probes, which consists of 2-(2'-OH-phenyl)-5-phenyl-1,3-oxazole, 2-(2'-OH-phenyl)-5-(4'-phenyl-phenyl)-1,3-oxazole and 2-(2'-OH-phenyl)-9,10-phenantr-1,3-oxazole, has been suggested to study the influence of low molecular weight cryoprotectants, such as glycerol, dimethylsulfoxide and 1,2-propanediol, on human erythrocyte membranes. Using a set of fluorophores with different locations in lipid bilayer enabled to show that under the action of the cryoprotectants the increase in the membrane hydration occurs in polar regions of the erythrocyte membrane, while no changes in hydration have been observed in the most hydrophobic regions of the erythrocyte lipid bilayer. The minimal concentration of the cryoprotectant, which causes the perturbation of the erythrocyte membrane, has been estimated to be 0.5, 1.5 and 5.0 % vol. for glycerol, dimethylsulfoxide, and 1,2-propanediol, correspondingly. The suggested set of fluorescent probes can be used to monitor the changes of physico-chemical properties in different regions of erythrocyte lipid bilayer under the action of cryoprotectants and to determine optimal concentrations of cryoprotectants for low-temperature storage of the cells.