Gurina T. Designing the optimisation algorithm for cryopreservation protocols of cell suspensions with regard to physical effects within subzero temperature range.

Research object - cryopreservation of cell suspension. Aim - theoretical and experimental study of freezing-thawing regimes for which the cooling-warming rate have different meaning in various temperature ranges and development of the algorithm for determining the values of these temperature ranges and cooling-warming rates in them. Research method - thermography, thermomechanical analysis, physical and mathematical modeling, cryopreservation, radioimmunoassay, flow cytometry,histological analysis,statistical analysis. Basing on theoretical analysis and specially designed experiments there were emphasized the physical phenomena and processes, occurring in cryoprotective medium within the range of subzero temperatures, which caused cell cryodamages during bioobjects' low temperature preservation. Using thermomechanical analysis there was designed the technique to determine the temperature intervals, corresponding to phase transition in cryoprotective solution, the general principles of selecting numerical values of controlled colling and warming rates within the mentioned temperature intervals were formulated. There was proposed the optimisation algorithm for cell suspension cooling-heating regimens, based on the coordination of freeze-thawing regimen parameters both with biophysical, transport and geometric characteristics of cryopreserved cells and with peculiarities of phase-structure transformation in cryoprotective medium.