Theoretical And Experimental Study Of Cryopreservation Of Umbilical Cord Blood By Vitrification

The idea of cryopreservation umbilical cord blood by vitrification was put forword in this paper firstly. The corresponding theoretical and experimental research was studied.In the presence of dimethyl sulfoxide (DMSO), a three-part, coupled model cell dehydration, nucleation and crystal growth was used to study intracellular ice formation (IIP) in umbilical cord blood during the cooling and warming process. The model correctly predicted and explained the effect of cooling rate and warming rate on the intracellular ice formation during the cooling and warming process. The cooling and warming rate which can realize vitrification and avoid devitrification was gained. This is to say, when the cooling rate is not less than 400℃/min and the warming rate is not less than 500℃/min, intracellular ice formation can be avoided. The above gotten result can provide the use for reference to the experimental study.Experimental study of cryopreservation of umbilical cord blood by vitrification was investigated by 2-step. The umbilical cord blood solution, which the DMSO concentration is 1.0M, 1.5M and 1.75M,was confected. The solution was in equilibrium for 20 minutes. Then, the umbilical cord blood was completely immerged in liquid nitrogen for about 24 hours. Then, the umbilical cord blood was taken out and was warming in the thermostat water bath for 20 minutes. The fraction surviving of the umbilical cord blood was more than 80%. The cooling rate and the warming rate were morethan 800℃/min in the range from -100℃ to 0℃ . Intracellular ice formation almost occurred during the cooling and warming process. Cryopreservation umbilical cord blood by vitrification realized successfully. The result was in well agreement with the theoretical conclusion.This dissertation was support by sustentation fund for science (Authorized number: 50076039).