Slow-freezing cryopreservation of red blood cells under the control of an AC elecric field

It is well known that amorphous ice can be used to cryopreserve biomaterials for transplantation. The main issue in this process is that liquid-solid phase transition of water. Due to the polarization of water, amorphous ice may be induced by AC electric filed. In this paper, AC electric field was applied to cryopreserve red blood cells (RBCs) to improve their viability. First, an electro-controlling apparatus for slow-freezing was established. Chicken RBCs were chosen as the sample because it is nucleated cell and it is convenient to estimate the cell viability. RBCs were cryopreserved under the control of an AC electric field at -30 °C for 24h and cell viability after thawing in a thermostatic waterbath at 37±0.5°C was determined by microscope. The result shows that the survival RBCs maintained the integrity of morphological. In the presence of AC electric field (E_max=1.63×10⁵V/m, f=1MHz), the survival rate is 23.4±1.41%, lower than the effect of cryoprotectant (dimethyl sulfoxide, 3.3wt.%), that is, 33.2%±2.57%. the highest cell viability up to 48.4±1.54% was obtained under the above two conditions together. These results indicate that AC electric field can contribute to the success of slow-freezing cryopreservation.