DEPARTMENT OF LOW-TEMPERATURE PRESERVATION

HISTORY OF THE DEPARTMENT

The Department of Low-Temperature Preservation exists as a structural unit since the very first days of the Institute for Problems of Cryobiology and Cryomedicine of the National Academy of Sciences of Ukraine establishing in 1972.
>>Learn more about the history

From 1972 to 1995, the Department was headed by one of the founders of the Institute and its first director, corresponding member of the National Academy of Sciences of Ukraine and the Academy of Medical Sciences of Ukraine, Prof., MD, Mykola S. Pushkar. The Department initiated the studies on creating approaches and methods for exploring the cryobiological processes. There was designed a  cryomicroscopic assembly and the studies of crystallization processes in biological systems began. This was developed by Leonid F. Rozanov and Larisa G. Kuleshova. The Department  has developed theoretical approaches and creates physical and mathematical theories and models of the phenomenon of transmembrane mass transfer and other processes that occur at different stages of the low-temperature preservation cycle. Theoretical modeling formed the basis for the development of new research methods: determining the permeability coefficients of cell membranes for water molecules and CPAs, determining optimal cryopreservation modes. The direction of research on the cryopreservation of fish sperm was also actively developing. Expeditions were organized to different parts of the country to carry out work in fish breeding sites. One of the main performers of this topic was Yevhen F. Kopeika. Other employees of the Department also took an active part in the expeditions (Novikov O.M., Gordienko E.O., Bronshtein V.L., etc.). The core of the low-temperature preservation Department later became the Laboratory of Theoretical Foundations of Low-Temperature Preservation, established in the department in 1985, consisting of: Rozanov L.F. (head of the laboratory), Gordiyenko E.O., Bronshtein V.L., Iserovych P.G., Ishkov G.S., Kuleshova L.G., Gordienko O.I., Kuleshova L.G., Stus L.K., Nekoz I.O., Krykunov V.V., Kuraksa V.M., Smolyaninova Ye.I., Kovalenko I.F., Makedonska V.O.. The laboratory conducted consistent theoretical studies of the mechanisms of cryodamage of biological objects, developed theoretical approaches to solving the problems of preserving living cells at low temperatures. Since 1995, the Department of Low-Temperature Preservation has been headed by Doctor of Biological Sciences, Prof. Yevhen  O. Gordiyenko. The main areas of scientific research under the leadership of Yevhen O. Gordienko were as follows:  theoretical analysis and experimental study of the causes and mechanisms of cryodamage and cryoprotection of cells for the development and improvement of technologies for long-term storage of biological objects in a viable state. Physical and mathematical theories and models of the transmembrane mass transfer, processes occurring at different stages of the low-temperature preservation cycle are being developed and investigated: inhibition of activation-type processes in environments with high viscosity; lateral separation of components of the cell membrane deformed by bending or isotropic tension; hypertonic cryohemolysis and post-hypertonic hemolysis; mechanical interaction of growing ice crystals with cells in a freezing suspension. Theoretical modeling of biological processes formed the basis for the development of new research methods. Based on the created theoretical models, experimental methods were developed for determining the permeability coefficients of cell membranes for electrically neutral substances, the distribution of erythrocytes by the sphericity index, and the coefficient of thermal expansion of erythrocyte membranes.  In 2007, within the framework of the state program for the modernization of the scientific equipment park of the NAS of Ukraine, an LSM 510 META microscope was purchased, on the basis of which a shared facility center was created. >> learn more about the center.  All the studies with the microscope is supervised by senior researcher of the Department, Ihor F. Kovalenko, PhD (Biology), Senior Researcher. Since 2015, the Department has been headed by Doctor of Physical and Mathematical Sciences, Prof. Olga I. Gordiyenko. Since 2021 the Department is performing researches on  theoretical and experimental study of the electrical characteristics of cell membranes at the stages of cryopreservation and their relationship with the ability of cells to adhere to flat surfaces and in volumetric structures.

RESEARCH DIRECTIONS

The main research directions of the Department are theoretical analysis and experimental study of the causes and mechanisms of cryodamage and cryoprotection of cells for the development and improvement of techniques for long-term storage of biological objects in a viable state. Physical and mathematical theories as well as models of transmembrane mass transfer, processes occurring at different stages of the low-temperature preservation cycle are being developed and investigated. Theoretical modeling of biological processes formed the basis for the development of new research methods. Based on the created theoretical models, experimental methods were developed for determining the permeability coefficients of cell membranes for electrically neutral substances, the distribution of erythrocytes by the sphericity index, and the coefficient of thermal expansion of erythrocyte membranes. A physical and mathematical model of transmembrane substance transport has been developed, which assumes the transmembrane transfer of basic ions and the related changes in the transmembrane potential. Calculations based on this model provide more accurate values ​​of cell membrane permeability coefficients for water molecules and cryoprotectants. The model allows us to determine the dynamics of the cell transmembrane potential and the duration of the membrane’s stay under the influence of a changed electric potential during equilibration in cryoprotectant solutions. A new approach to solving the problem of optimizing the freezing conditions of biological objects is theoretically substantiated and experimentally confirmed. A quantitative model of cell cryodamage at the crystallization stage is formulated, which makes it possible to determine the optimal conditions for their cooling, based on a small amount of data on the transport and geometric parameters of these cells. An algorithm for estimating the value of the optimal, from the point of view of the two-factor theory of cryodamage, cooling rate of a cell suspension at the stage of its crystallization is constructed. A theoretical approach to cryopreservation of multicellular spheroids using physical and mathematical modeling is proposed. The spheroid is considered as a holistic object in toto, and the integral characteristics that determine the time parameters of mass exchange between the spheroid and the environment are analogs of the permeability coefficients of the membranes of individual cells. Based on the probabilistic physical and mathematical model and taking into account the determined integral characteristics of spheroids, the optimal cooling rate is determined.

Department Topics

The main areas of the Department’s work are fundamental theoretical studies of the causes and mechanisms of cryodamage and cryoprotection at the cellular level. Physical and mathematical theories and models of the phenomenon of transmembrane mass transfer are developed and investigated, as well as processes occurring at different stages of the low-temperature preservation cycle:

• inhibition of activation-type processes in media with high viscosity;
• lateral separation of cell membrane components deformed by bending or isotropic tension;
• hypertonic cryohemolysis; crystallization hydrolysis;
• mechanical interaction of growing ice crystals with cells in a frozen suspension.

CURRENT RESEARCH

• Theoretical justification and experimental confirmation of the methods for increasing the adhesive capacity of cells before and after cryopreservation by modifying the physicochemical characteristics of the substrate and the surface of cell membranes
• To establish mechanisms and create a physical and mathematical theory of cell cryodamage under the influence of electrical voltages that arises during low-temperature preservation of cell suspensions
• Theoretical and experimental study of the electrical characteristics of cell membranes at the stages of cryopreservation and their relationship with the ability of cells to adhere to flat surfaces and in volumetric structures

DEPARTMENT STAFF

• Ihor F.  KOVALENKO, PhD (Biology), Senior Researcher orcid: 0000-0002-7063-6712
• Svitlana Ye. KOVALENKO, PhD (Biology), Senior Researcher orcid: 0000-0001-7351-5767
• Yevheniia I. Smolyaninova, PhD (Biology), Senior Researcher orcid: 0000-0003-4231-8976
• Oleksandr  F. TODRIN, PhD (Biology), Senior Researcher orcid: 0000-0002-3481-282X
• Lyudmila I.  POPIVNENKO , PhD (Physics  and Mathematics), Senior Researcher orcid: 0000-0001-7465-7329
• Valentyna O. MAKEDONSKA, PhD (Medicine), Senior Researcher orcid: 0000-0003-3256-8939
• Olena V. TYMOFEYEVA, PhD (Physics  and Mathematics), Senior Researcher orcid: 0000-0001-9746-3826

CONTACT PERSON

Olga  I. GORDIENKO
e-mail: info@cryonas.org.ua