Improvement of Cryopreservative Effect of Natural Killer Cell by Increasing Membrane Rigidity Using Static Magnetic Field

The transfusion of natural killer (NK) lymphocytes into patients suffering from malignant diseases is an approach of current interest in the field of immunotherapy. To ensure the resource of NK cell supplement is stable, cryoprotection of health NK cells for future application was proposed. However, until now, addition of cryoprotectant is the major strategy for cryoprotection of sourcing cells. Since cryoprotectants have cytotoxic effects on the protected cells, a removing procedure, which cost time and may result in cell damage, is necessary before transfusion. In our previous reports, we found that static magnetic fields (SMF) has strong effects on the rigidity of cellular membrane. Accordingly this proposal hypothesizes that cells exposed to a strong SMF during cooling stage has positive effects for protecting the frozen cells from damage of ice crystal. It is helpful for increasing the recovery rate of the frozen NK cells after thawing. With this regard, in this proposal, we designed experiments to test this hypothesis. The NK cells will be cryo-preserved with 8000 Gauss SMF. The recovery rate, ultra morphology and cytotoxicity of the SMF-cryopreserved NK cells will be evaluated after they were thawing. After finish all the tests, we will provide more insight into the mechanism and performance of SMF-coupling freezing process, and the results of this study will be a useful guide and reference for future advanced investigations.