Solute-solvent interaction strength of disaccharide aqueous solutions:: Trehalose primate

Results of density, ultrasonic velocity, and DSC measurements performed on aqueous solutions of the homologous disaccharides trehalose, maltase and sucrose, are reported. To get some insight into the mechanisms of cryopreservation that characterize these systems, and to clarify the reasons that make trehalose the most effective bioprotector, we investigate the volumetric and thermic properties of trehalose, maltose and sucrose aqueous solutions as a function of concentration and temperature. What conclusively emerges is the presence of a more collapsed conformation for trehalose in respect with the other disaccharides, indicative of a much more marked solute-solvent interaction strength. Moreover, DSC findings indicate a greater effectiveness of trehalose in destroying the tetrahedral network of water compatible with the formation of ice and support the hypothesis of a higher "fragile" thermodynamic character of the trehalose-water system at high dilution.