Dynamics of trehalose molecules in confined solutions

The dynamics of trehalose molecules in aqueous solutions confined in silica gel have been studied by quasielastic neutron scattering (QENS). Small-angle neutron scattering measurements confirmed the absence of both sugar clustering and matrix deformation of the gels, indicating that the results obtained are representative of homogeneous trehalose solutions confined in a uniform matrix. The pore size in the gel is estimated to be 18 nm, comparable to the distances in cell membranes. For the QENS measurements, the gel was prepared from D2O in order to accentuate the scattering from the trehalose. Values for the translational diffusion constant and effective jump distance were derived from model fits to the scattering function. Comparison with QENS and NMR results in the literature for bulk trehalose shows that confinement on a length scale of 18 nm has no significant effect on the translational diffusion of trehalose molecules.