CREATION OF THE ОPTIMAL MEDIA FOR PLACENTAL TISSUE EXPLANTS CRYOPRESERVATION

Phase transitions and vitrification of multicomponent cryoprotective media including NaCl, dimethyl sulfoxide, sucrose, polyvinylpyrrolidone, dextran and hydroxyethylic starch for cryopreservation of explants of placental tissue as well as its morphological integrity after cryopreservation in these media with the aim of adequate selection of the components were studied by differential scanning calorimetry. Analysis of the obtained thermograms has shown that in all multicomponent cryoprotective media, frozen with a high rate, the part of the solution transforms into a vitrified state during warming ice crystallization from amorphous phase and melting of solution area with eutectic composition are absent. Minimal intensity of endothermal effect of ice melting as well as the highest morphological integrity of placental tissue is observed in multicomponent solutions containing 5% dimethyl sulfoxide and 6,8% sucrose or 5% hydroxyethylic starch in physiological solution. These media should be considered as optimal ones for cryopreservation of placental tissue explants, and their composition is recommended to be used when designing complex cryoprotective media.