Problems of Radiation Medicine and Radiobiology

D. I. Bilko¹, R. V. Boiko¹, I. Z. Russu¹, I. S. Dyagil², N. M. Bilko¹

¹National University of Kyiv-Mohyla Academy, 2 Grygoriya Skovorody St., Kyiv, 04070, Ukraine
²State Institution «National Research Center for Radiation Medicine of the National Academy of Medical
Sciences of Ukraine», 53 Yuriia Illienka St., Kyiv, 04050, Ukraine

ANALYSIS OF THE INFLUENCE OF PROLONGED IRRADIATION ON HEMATOPOIETIC PROGENITOR CELLS IN GEL DIFFUSION CHAMBERS USING MATHEMATICAL MODELLING

Objective: determining of the functional activity of mice bone marrow hematopoietic progenitor cells, cultivated in gel diffusion chambers, on the stages of hematopoiesis recovery after their prolonged irradiation in the lethal dose in a comparative aspect with the method of colony forming in spleen using mathematical model.
Materials and methods. The method of cell cultivation in gel diffusion chambers, cytological methods, mathematical modeling, and statistical methods of research were used. Bone marrow samples extracted from the femur of mice irradiated with a total dose of 8 Gy with a power 0.0028 Gy/min were cultivated in diffusion chambers with semisolid agar in the abdominal cavity of CBA recipient mice.
Results. Comparative analysis of the colony-forming efficiency of progenitor cells (CFU) was carried out during cultivation in gel diffusion chambers in the process of hematopoiesis recovery for 30 days, as well as in the spleen of lethally irradiated animals, in accordance with the mathematical model. Analysis of colony forming kinetics in gel diffusion chambers after prolonged exposure to ionizing radiation indicated the biphasic nature of hematopoiesis recovery. Thus, in the first few days after the irradiation a drop in the number of CFU is observed compared to the control, which continues until the 9^th day. Subsequently there is a sharp increase in the number of CFU in cell culture, which continues until the complete recovery of hematopoiesis. The obtained data, recalculated per mouse femur, correspond to the results of colony forming in the spleen of irradiated animals, described by K. S. Chertkov and taken as a basis while developing our mathematical model, as well as to its parameters, which describe the process of hematopoiesis recovery.
Conclusions. Conformity of the indices obtained during the cultivation using the method of gel diffusion chambers of mice bone marrow prolongedly irradiated at a total dose of 8 Gy with a power 0.0028 Gy/min, to the results of colony forming in spleen of lethally irradiated mice, which were the basis for mathematical model development, is the evidence of the feasibility of using a mathematical model to assess the process of hematopoiesis recovery by progenitor cells of different maturation levels, and the experimental approach of CFU growing in gel diffusion chambers can be considered as an additional method of researching the hematopoiesis recovery along with the spleen colony method.
Key words: hematopoietic progenitor cells, external prolonged irradiation, cell culture in gel diffusion chambers, kinetics of hematopoiesis recovery, mathematical modelling.

Problems of Radiation Medicine and Radiobiology.
2022;27:203-215. doi: 10.33145/2304-8336-2022-27-203-215

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