Preferential interaction of dimethyl sulfoxide and phosphatidyl choline membranes

Abstract

The interaction free energy of dimethyl sulfoxide (DMSO) and two types phospholipid membranes has been assessed from measurements of vapor pressure. The lipids were phosphatidyl cholines with respectively (14:0/14:0) (DMPC) and (16:0/18:1) (POPC) fatty acid chains. The results were expressed in terms of the iso-osmolal preferential interaction parameter, Gamma(mu1), which remained negative under all experimental conditions investigated here. This shows that water-membrane interactions are more favorable than DMSO-membrane interactions. This condition is known as preferential exclusion of DMSO (or preferential hydration of the membrane), and implies that the local (interfacial) concentration of the solute is reduced compared to the bulk. At room temperature and 1 m DMSO, Gamma(mu1) was -0.3 to -0.4 for both lipids. This corresponds to a sizable reduction in the DMSO concentration in a zone including at least the first two hydration layers of the membrane. Possible origins of the preferential exclusion are discussed. As a direct consequence of the pronounced preferential exclusion, DMSO generates an osmotic stress at the membrane interface. This tends to stabilize lipid phases of low surface areas and to withdraw water from multilamellar stacks of membranes. Based on this, we suggest that the preferential exclusion of DMSO explains both the modulation of phase behavior and the constriction of multilamellar aggregates induced by this solute.

The Effect of an Intramembrane Light-Actuator on the Dynamics of Phospholipids in Model Membranes and Intact Cells

“…Specifically, the effect of DMSO on model membranes has been studied extensively in the last two decades, owing to its large use as cryoprotectant in cellular systems and vehicle solvent for a number of drugs. 44,[46][47][48][49][50][51] It has been observed that if employed at concentrations < 10 mol.%, which is in line with our concentration of 0.3 mol.%, DMSO tends to dehydrate the membrane by disrupting the dynamic hydrogen-bond water near the lipid membrane surface. 50 This causes a drastic decrease in the range of the steric hydration repulsion, leading to a reduction of the solvated volume of the phospholipid head groups.…”

Cryoprotectant Toxicity: Facts, Issues, and Questions

“… 59 At 77°C, DMSO decreases cell membrane thickness at low concentrations (2.5%–7.5%), causes the formation of transient water pores at intermediate concentrations (10%–20%), and destroys the bilayer structure at higher concentrations (25%–30%). 52 Although DMSO can stabilize the gel phase of cell membranes, 60 above concentrations of 40% DMSO causes the gel-phase structure of ceramide bilayers to undergo a phase transition from gel to liquid crystalline. 61 All of these effects should increase with increasing temperature.…”

“…Membranes are more readily “hydrated” by water than by DMSO, and this relative exclusion of DMSO reportedly causes stress at the membrane interface. 60 DMSO hydrophobicity and concentration in the lipid bilayer decreases with increasing temperature, which may help explain the increasing toxicity of DMSO with increasing temperature because DMSO localizes around the polar head groups of cell membranes. 60 , 77 , 78 For temperatures above 5°C, addition of FMD to DMSO increases liposome disruption.…”

Influence of the Membrane Dye R18 and of DMSO on Cell Penetration of Guanidinium‐Rich Peptides

“…Effects of DMSO on the properties of phospholipid bilayers have been extensively studied for decades . The subjects of these investigations were planar bilayers, unilamellar and multilamellar vesicles (liposomes), lipid membranes, and living cell membranes.…”