Comparative Analysis of Cryopreservation Methods for Expanded Ex Vivo Natural Killer Cells: Recommendations for Optimizing Research Technologies
Purpose. On the basis of a comparative analysis of known cryopreservation technologies for expanded ex vivo natural killer cells, to recommend for use the most effective NK cells in terms of preserving the viability. Materials and methods. The study included 10 samples of expanded ex vivo human EK cells, frozen in 4 types of cryoprotective mixtures using various freezing techniques and stored for 30 days in liquid nitrogen vapor. The safety of the samples after thawing was assessed in terms of viability, cytotoxic activity, and phenotypic cell profile. Results. Among the cryoprotective mixtures studied by us, the best results of preserving the viability and cytotoxic activity of expanded ex vivo NK cells after cryostorage were obtained for two variants of mixtures: the key components of the first mixture are FBS (25%) and DMSO (10%); the second components are dextran and DMSO (5%). Conclusion. Among the studied cryoprotectant, the best results of viability and cytotoxic activity of expanded ex vivo EK cells after cryostorage were obtained for two variants of agents: the key components of one of them are ETS (25%) and DMSO (10%); the other components are dextran and DMSO (5%).