Membrane permeabilization of phosphatidylcholine liposomes induced by cryopreservation and vitrification solutions.

Membranes are the primary site of freezing injury during cryopreservation or vitrification of cells. Addition of cryoprotective agents (CPAs) can reduce freezing damage, but can also disturb membrane integrity causing leakage of intracellular constituents. The aim of this study was to investigate lipid-CPA interactions in a liposome model system to obtain insights in mechanisms of cellular protection and toxicity during cryopreservation or vitrification processing.

Stallion Sperm Cryopreservation Using Various Permeating Agents: Interplay Between Concentration and Cooling Rate.

In this study, modeling and experimental approaches were used to investigate the interplay between cooling rate and protectant concentration for cryopreservation of stallion sperm. Glycerol (GLY), ethylene glycol (EG), dimethylformamide (DMF), propylene glycol (PG), and dimethyl sulfoxide (DMSO) were tested as cryoprotective agents (CPAs), using concentrations up to 1500 mM and cooling rates ranging from 5°C to 55°C min. Modeling of the extent of sperm dehydration during freezing was done using previously determined values of the sperm membrane permeability to water to predict optimal cooling rates for cryopreservation.