Scientific Results

Influence of Dimethyl Sulfoxide on the Low-Temperature Behavior of Cholesterol-Loaded Palmitoyl-oleyl-phosphatidylcholine Membranes

Year: 2018

Authors: Gironi B., Paolantoni M., Morresi A., Foggi P., Sassi P.

Autors Affiliation: [Gironi, Beatrice; Paolantoni, Marco; Morresi, Assunta; Foggi, Paolo; Sassi, Paola] Univ Perugia, Dipartimento Chim Biol & Biotecnol, Via Elce Sotto 8, I-06123 Perugia, Italy.
[Foggi, Paolo] Univ Firenze, European Lab Non Linear Spect LENS, Via Nello Carrara 1, I-50019 Florence, Italy and CNR, INO, Via Nello Carrara 1, I-50019 Florence, Italy and CNR, ICCOM, Via Madonna del Piano 10, I-50019 Florence, Italy.
[Sassi, Paola] Univ Perugia, CEMIN, Via Elce Sotto 8, I-06123 Perugia, Italy

Abstract: The properties of lipid membranes at low temperature are important for a number of biomedical and biotechnological applications, and the success of these applications depends on understanding the effects of temperature changes on intermolecular lipid-lipid and lipid-water interactions. Here, we use Fourier transform infrared spectroscopy to study lipid suspensions in water/dimethyl sulfoxide (DMSO) solutions in the -60 to 30 degrees C range. DMSO is a cryopreservative agent of cellular systems, and its action is largely related to its interaction with the lipid membrane, especially in the low- temperature regime. In the present work, we analyze the effects of solvent composition on the structural and thermotropic properties of cholesterol (chol)-loaded liposomes of palmitoyl-oleylphosphatidylcholine (POPC) because POPC/chol liposomes are suitable models of the plasmatic membrane. To this extent, we compare the properties of lipid vesicles suspended in water and water/DMSO solution at 0.10 DMSO mole fraction and we observe that the gel phase of the membrane has an increased thermal stability on DMSO addition. We estimate that the amount of unfrozen water at T = -60 degrees C is much reduced by the presence of DMSO, both in the gel- and the liquid-ordered phase of the membrane. Interestingly, we also evidence a reduced hydration of the lipid heads in the presence of DMSO when the vesicles are dispersed in a liquid solution, whereas the addition of DMSO does not alter the hydration state of phosphate and carbonyl groups in the frozen state of the membrane.

Journal/Review: JOURNAL OF PHYSICAL CHEMISTRY B

Volume: 122 (24)      Pages from: 6396  to: 6402

More Information: AQUEOUS-SOLUTIONS; PHASE-TRANSITION; CELL-MEMBRANES; WATER; CRYOPRESERVATION; LIQUID; BILAYERS; RAFTS; VITRIFICATION; LIPOSOMES
KeyWords: aqueous-solutions; phase-transition; cell-membranes; water; cryopreservation
DOI: 10.1021/acs.jpcb.8b02333

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