The Effects of Sugar Osmolytes on Reverse Micelle Systems

Reverse Micelles (RM) are nanoscopic pools of water encapsulated by an amphipathic surfactant molecule that allows the water pool to be suspended in a nonpolar solvent. We use RM systems because they allow for the study of water and dissolved osmolyte interactions in confinement. Gaining an understanding of how sugars interact with water in confinement has significant implications for biological systems. This project seeks to understand the effects of galactose as an osmolyte on the interactions, loading limits, and size of RMs when compared to RMs containing only water and RMs containing glucose. Galactose and glucose have slight structural differences, varying in the position of the hydroxyl group on the fourth carbon of each molecule allowing us to probe the structural nuances that often have large biochemical effects. RMs prepared using the surfactant Docusate Sodium (AOT) and the nonpolar solvent isooctane (2,2,4- trimethylpentane) were made in sizes of w0=5, 10, and 20 where w0 represents the ratio of the concentration of water to the concentration of surfactant ([water]/[surfactant]). The loading limit of galactose in RMs was determined to be less than that of glucose over a range of RM sizes with the highest loading limit found in w0= 10 RMs. RM systems were also analyzed using Dynamic Light Scattering (DLS) to determine the impact of the osmolyte on RM size. We observed a reduction in the size of RMs when loaded with a sugar osmolyte, which we postulate happens because the interaction of the sugar with AOT headgroups disrupts the shape of RMs and causes a change in AOT surface area