EVALUATION OF THE CRYOPROTECTIVE EFFECT OF SUGARS ON SURVIVAL OF HUMAN ERYTHROCYTES CRYOPRESERVED AT -80°C

摘要

Sugars can be loaded into erythrocyte cytoplasma by simple incubation, which makes cryopreservation of human erythrocytes without glycerol feasible. The cryoprotective effect of sugars on human erythrocytes was evaluated in this study. Erythrocytes loaded with sugars were frozen in a formulation of polyvinylpyrrolidone, human serum albumin, and corresponding sugars. The data showed the efficiency of sugar loading was dependent on extracellular sugar concentration, incubation temperature and time. Sugars can decrease hemolysis and protect metabolic function of cryopreserved erythrocytes, especially for glucose. However, compared with glucose, trehalose can maintain phosphatidylserine distribution of cryopreserved erythrocytes. Finally, sugars can protect integrity of membrane morphology after freezing, but some cell shape appeared spherocytic or echinocytic. In conclusion, sugar loading benefits the survival of cryopreserved erythrocytes. But trehalose loading causes more cell injuries compared with glucose, and these injuries in turn manifest themselves during subsequent freezing and thawing.