Freezing under pressure: a new method for cryopreservation.

The ability to preserve cells, tissues, and organs with minimal damage for an extended period of time is essential for advancements in medicine and research. Current methods for cryopreservation are based on using high concentrations (up to 60% v/v) of cryoprotective agents (CPAs) which are toxic to living cells. The effect of pressure and a low concentration of dimethyl sulfoxide (Me2SO) or glycerol, on hemolysis of human red blood cells (RBCs) after freezing and thawing were investigated. Pressure was applied during cooling and freezing the RBCs and a minimum in hemolysis was reached at approximately 120 MPa. Either 5% v/v Me2SO or 8% v/v glycerol concentration in combination with 120 MPa pressure was sufficient to obtain 8% or less hemolysis of RBCs after cooling at a 35 °C/min or a 160 °C/min rate. The preliminary results suggest that the method may help to solve the CPAs toxicity problem.