Confinement effect on thermal properties of cryoprotective solutions

Vitrification of biological tissues requires the use of highly concentrated cycloprotective solutions in conjunction with fast rater; to avoid the formation of ice crystals. The lowest rates necessary are evaluated by differential scanning calorimetry. They have been calculated in several samples of biological tissue previously impregnated with a cryoprotective solution, and are lon;er than the corresponding rates of the bulk solution To verify the confinement effect, we have conducted a more systematic study in a number of porous and inert materials (pore size from 2 nm to 100 mu m). In each of these materials, we observed a systematic decrease of the critical rates, but did not find a correlation between this decrease and the size of the pores In addition, our measurements also showed a systematic increase in the vitreous transition temperature T-g. which contradicts most of the latest work on this subject involving pure liquids. We wish to continue this work with a more in-depth study on a porous material with which we can control and change the porosity and the hydrophilic characteristics.