Evidence for this form of damage is derived partly from experimental observation that inclusion of cryoprotectants
such as glycerol, which break up the extreme rigidity of pure water ice, correlate with better retention of DNA quality after freezing.
toxicity is probably reduced by lowering the temperature of exposure.
Fahy and his colleagues were able to develop a vitrifying cryoprotectant
solution that is nontoxic enough for preserving large organs.
After centrifugation, the pellet was divided in three parts, one with and one without cryoprotectants
respectively (2% w/w glycerol or 5% w/w maltodextrine) [3, 4]) and freeze-dried in a low freeze-drier (LOUW KOELTECHNIEK BVBA) with a standard program by increasing the temperature gradually from - 25[degrees]C to 25[degrees]C at 0,9 mbar pressure during 48h.
toxicity may cause cell injury in association with distinct ultrastructural changes, especially in the plasma membranes .
Embryos were moved through three increasing levels of cryoprotectant
to help remove water from the cells.
In a few exceptional cases, a single cryoprotectant
usually DMSO is effective, however, a cryoprotectant
mixture consisting of DMSO, glycerol, and the third component such as sucrose, proline, mannitol or sorbitol is usually far more effective (Withers, 1991).
Many workers have used 15 per cent glycerol (1,7,9,11,12) as a cryoprotectant
, while others have used DMSO (2,5,12).
In cold environments, DMSP may act as a cryoprotectant
, keeping the cell from freezing.
It has a membrane stabilization property and acts as a cryoprotectant
(Orthen and Popp, 2000; Hincha and Hagemann, 2004).
For example, a heterogeneous distribution of a cryoprotectant
, such as a sugar, can have important consequences upon the activity of the drug substance when it is a peptide or protein, as a change in tertiary structure and concomitant loss of potency can often be an outcome in its absence.
However, when freeze casting aqueous alumina slurries in bulk the addition of small amounts of glycerol to the slurry mix serves as a cryoprotectant
, effectively disrupting the crystalline behaviour of water contained in the slurry (Sofie and Dogan, 2001).