Use of lactulose in the composition of blood cell cryopreservatives

Introduction . Cryopreservation allows for long-term conservation of biomaterials. The insufficient efficacy of available cryopreservatives and the toxicity of a number of cryocomponents renders the search for low-toxic biocompatible cryoagents highly relevant. Objective . Assessment of morphological and functional features of blood cells in a lactulose-based cryopreservative for storing whole blood at moderately low temperatures (minus 20 °C) using leukocyte, platelet, and erythrocytes parameters. Materials and methods. The study was conducted using peripheral venous blood of 30 female donor volunteers aged 18–23 years. Samples of peripheral venous blood were stabilized by 3-substituted potassium salt of ethylenediaminetetraacetic acid. The cryopreservative was prepared using a 0.9 % sodium chloride solution to maintain the isotonic concentration. Glycerin and dimethyl sulfoxide were used as cell-penetrating cryoprotectors; lactulose disaccharide was used as a non-penetrating cryoprotector. The composition of the obtained cryopreservative was optimized by varying the mass fractions of the components. Clinical blood tests were performed using a Gemalite 1270 automatic hematology analyzer. A computer cytomorphometric study was performed in the MEKOS-C2 hardware and software environment. Results . The conservation of blood samples using the developed cryopreservative for 24 h at a temperature of minus 20 °C increased the percentage of preserved leukocytes, erythrocytes, and platelets to 88.6±0.41 %, 92.1±0.31 %, and 91.4±0.52 %, respectively. The blood cells retained their physiological activity after thawing compared to blood samples stored at room temperature. Conclusions . The morphological and functional safety of blood cells in samples stored with the developed cryopreservative was revealed after 24 h of storage at minus 20°C. The advantages of this cryopreservative include the possibility of its long-term storage without loss of cryoprotective properties, stabilizing blood cells to the effects of sub-moderate low temperatures of minus 20 °C, the use of non-toxic lactulose disaccharide that does not penetrate into the cell. The developed cryopreservative proves effective in freezing conditions at minus 20 °C, being affordable in terms of cost (all components are manufactured in the Russian Federation). Further research in this direction will contribute to the development of safer blood donation approaches and reducing complications during transfusion of blood components.