The relation between cryoprotective and physicochemical properties of oxyethylated methyl cellosolve-based media

Oxyethyl derivatives of polyol class members such as glycerol and ethylene glycol with various polymerization degrees possess low toxicity and cryoprotective properties via an exocellular mechanism. To develop the cryoprotective media based on non-penetrating cryoprotectants, we studied cryoprotective and physico-chemical properties of oxyethylated methyl cellosolve (OEMC)-based media. Media containing 20% and 30% OEMC were prepared with 50 mmol/l and 150 mmol/l NaCl. In some media, NaCl content was reduced, and sucrose, mannitol or glucose was added to attain the isotonic media. Cryopreservation of red blood cells depends on the media composition and physico-chemical properties. The increases in dynamic viscosity due to higher OEMC concentration and in ionic strength resulted from higher NaCl concentration lead to greater erythrocytes dehydration prior to freezing, and lower red blood cell preservation upon freezing. Salt substitution with carbohydrates in 20% OEMC media reduces ionic strength and increases OEMC distribution coefficient. The correlation of red blood cell protection upon freezing is discussed in terms of the media physico-chemical properties (ionic strength, viscosity and surface tension), cryoprotectant distribution coefficient, and cell dehydration.