Role of trehalose in prevention of giant vesicle adsorption and encapsulated solute leakage in anhydrobiotic preservation

Anhydrobiotic preservation has the potential to allow the processing and storage of mammalian cells in a state of suspended animation at ambient conditions in trehalose glasses; however, stresses--particularly to the lipid bilayer--during desiccation and rehydration have thus far prevented the full realization of the promise of this technique. Giant gel-phase 1,2-distearoyl-sn-glycero-3-phosphocholine (DSPC) and liquid-crystalline-phase 1,2-dilauroyl-sn-glycero-3-phosphocholine (DLPC) vesicles provide a model cell system with which to elucidate the role of trehalose in surface-lipid bilayer interactions, as well as the part played by lipid phase. In the absence of trehalose, DSPC liposomes adsorbed to polystyrene, producing irreversible structural changes and apparent leakage of all intravesicular solute upon drying and rehydration. Addition of trehalose significantly reduced vesicle adsorption with only transient intravesicular solute leakage for the rehydrated vesicles; however, at very low moisture contents, the vesicles underwent permanent structural changes. In contrast to the results with DSPC vesicles, DLPC vesicles largely avoided adsorption and exhibited high intravesicular solute retention when dried and rehydrated even in the absence of trehalose, despite significant internal structural changes.