(327d) Understanding The Effects Of Trehalose On Dehydrated Domain-Exhibiting Supported Bilayers: An Atomic Force Microscopy And Fluorescent Microscopy Study

Atomic force microscopy (AFM) and fluorescent microscopy FRAP experiments have been applied to characterize hydrated, dried and rehydrated supported bilayers of coexisting fluid and gel phase phosphatidylcholines, either in the absence or in the presence of trehalose. The micron scale domain structure appears to be preserved in both cases as characterized by AFM and fluorescence microscopy. We show evidence of stronger mixing of high and low transition temperature lipids in mixed bilayers dried without trehalose. Mobility of the lipids evaluated through FRAP, shows recovery in bilayers after drying and rehydrating in the presence of trehalose. In correspondence, phase separation was correlated with height difference between the low (gel phase) and high (fluid phase) transition temperature lipid, showing a similar distribution of the difference of heights for rehydrated bilayers with trehalose with the hydrated lipid bilayers height distribution. We suggest that the strong effect of trehalose to stabilize the lipid bilayer is related to trehalose maintaining phase separation between lipid components of the lipid bilayer mixtures.