Membranes trehalose stabilization

Rudolph, A.S., Crowe, J.H. Crowe, L.M. (1986). Effects of three stabilizing agents - proline, betaine and trehalose on membrane phospholipids. Archives of Biochemistry and Biophysics, 245, 134-43. 

Rudolph, A. S., and Crowe, J. H. (1985). Membrane stabilization during freezing The role of two natural cryoprotectants, trehalose and proline, Cryobiology, 22, 367-377. 

Israeli et al. [3.31] found, that trehalose is a very good stabilizer for E, even if the freeze dried suspension of E was stored at 21 °C and 60 % relative humidity, and/or was exposed to visible light. In 3 h, the survival rate decreased without trehalose to 0.01 % under the influence of light and air, with trehalose, 35 % survived. The optimum trehalose concentration was found to be 100 mM. This corresponded with the number of trehalose molecules necessary to replace the water molecules in the outer membrane of the phospholipid molecules. 

The difference in the recovery of cortical neurons in the presence of these additives might be a result of the cryopreservation process that is explained as follows DMSO is taken up into the cell and allows vitrification of the intracellular solution, leading to the stabilization of the cell membrane. However, in the case of trehalose, the molecules may be too large to permeate into the cell they may only contact the membrane extracellularly and protect the cell from freezing damage. To clarify the details of this cryoprotection mechanism, we need to study the process of cell freezing. 

In this work, we have analyzed the phase behavior of various freeze-dried mixtures of DPPE, DPPC, and cholesterol and have examined the effects of trehalose addition to these liposomes. Generally, dehydration leads to increase in transition temperature of the phospholipids and also to phase separation. Addition of trehalose, however, can prevent the increase in transition temperature and phase separation freeze-dried DPPC-cholesterol liposomes exhibit only one transition and their retention capability increases by more than 40%. Further studies on the phase separation and stability of multicomponent model membranes will be required to understand better its relation to the survival of cells to freeze-drying procedures. 

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