Sucrose solutions alter the electric capacitance and dielectric permittivity of lipid bilayers

Vitkova, Victoria; Mitkova, Denitsa; Antonova, K.; Popkirov, G.; Dimova, Rumiana

doi:10.1016/j.colsurfa.2018.05.011

Cited by 24 publications

(15 citation statements)

References 46 publications

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“…Above this critical frequency, the shape becomes oblate. For

{\overset{C}{true}}_{normalm} ≫ 1

, a condition that is typically satisfied for membranes, the critical frequency can be approximated as [36]

ω_{c} = \frac{λ_{in}}{R C_{normalm}} \frac{1}{\sqrt{(() 1 - Λ) (() 3 + Λ)}} .

Thus, the membrane capacitance can be obtained from the experimentally measured critical frequency for prolate–oblate transition [26, 37]. The frequency‐dependent shape is described by

s false(\overset{ω}{true} false) = \frac{ε E_{0}^{2} R}{σ_{0}} \frac{p^{el} false(\overset{ω}{true} false)}{\exp (\frac{64 κ}{5 k_{B} T} s^{2} (\bar{ω}))} .

Figure 5 shows frequency‐sweep experimental data for the same vesicle analyzed in Fig.…”

Section: Resultsmentioning

confidence: 99%

Electromechanical characterization of biomimetic membranes using electrodeformation of vesicles

2021

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We describe a facile method to simultaneously measure the bending rigidity and capacitance of biomimetic lipid bilayers. Our approach utilizes the ellipsoidal deformation of quasi‐spherical giant unilamellar vesicles induced by a uniform AC electric field. Vesicle shape depends on the electric field frequency and amplitude. Membrane bending rigidity can be obtained from the variation of the vesicle elongation on either field amplitude at fixed frequency or frequency at fixed field amplitude. Membrane capacitance is determined from the frequency at which the vesicle shape changes from prolate to oblate ellipsoid as the frequency is increased at a given field amplitude.

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“…Above this critical frequency, the shape becomes oblate. For

{\overset{C}{true}}_{normalm} ≫ 1

, a condition that is typically satisfied for membranes, the critical frequency can be approximated as [36]

ω_{c} = \frac{λ_{in}}{R C_{normalm}} \frac{1}{\sqrt{(() 1 - Λ) (() 3 + Λ)}} .

Thus, the membrane capacitance can be obtained from the experimentally measured critical frequency for prolate–oblate transition [26, 37]. The frequency‐dependent shape is described by

s false(\overset{ω}{true} false) = \frac{ε E_{0}^{2} R}{σ_{0}} \frac{p^{el} false(\overset{ω}{true} false)}{\exp (\frac{64 κ}{5 k_{B} T} s^{2} (\bar{ω}))} .

Figure 5 shows frequency‐sweep experimental data for the same vesicle analyzed in Fig.…”

Section: Resultsmentioning

confidence: 99%

Electromechanical characterization of biomimetic membranes using electrodeformation of vesicles

2021

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“…Despite the different tension range in [58], it can be concluded that membrane thinning associated to tension only partially explains the differences in the capacitance data acquired from GUVs and from planar lipid membranes. In our previous study [16] providing the first experimental evidence about the influence of sucrose on the electrical properties of lipid bilayers, we explored the possibility of changes in membrane dielectric constant as a factor affecting the capacitance. Here, we relate the reported increase of the electric capacitance of the bilayer and the corresponding increase in its dielectric permittivity [16] in the presence of ≥200 mmol/L sucrose to possible alterations in membrane structure and organization induced by membrane-sugar interactions [64].…”

Section: Discussionmentioning

confidence: 99%

“…The ratios 0.87 ≤ Λ ≤ 0.95 correspond to a more conductive suspending solution. We perform data analysis following the original approach of Salipante et al [16,38].…”

Section: Electrodeformation Of Guvsmentioning

confidence: 99%

“…The quantification of the lipid bilayer capacitance and the estimation of its dependence on external factors allows for evaluating the charging time of membranes and membrane-field interactions, including transmembrane potential difference [15]. The alteration of the bilayer electrical capacitance in sucrose-containing solutions reported recently [16] emerged various questions regarding the effect on membrane electrical properties of dissolving simple carbohydrates in the aqueous surroundings.…”

Section: Introductionmentioning

confidence: 99%

“…Considering the close relation of the specific capacitance to membrane composition, its structure and physical state [17], we probe here the susceptibility of this important electrical parameter of lipid bilayers to the presence of sugar molecules in the aqueous surroundings. The effect of glucose, fructose and sucrose on the degree of hydration and rotational order parameter of lipid molecules is measured with regard to expected alterations of membrane dielectric permittivity [16,[18][19][20]. The specific capacitance of free-standing membranes is measured by frequency-dependent electrodeformation of giant unilamellar lipid vesicles (GUVs) and Fast-Fourier transform electrochemical impedance spectrometry (FFT-EIS) of planar bilayer lipid membranes (BLMs) for acquisition of the impedance spectrum (1 Hz-50 kHz) in a couple of seconds.…”

Section: Introductionmentioning

confidence: 99%

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Dielectric Properties of Phosphatidylcholine Membranes and the Effect of Sugars

et al. 2021

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Simple carbohydrates are associated with the enhanced risk of cardiovascular disease and adverse changes in lipoproteins in the organism. Conversely, sugars are known to exert a stabilizing effect on biological membranes, and this effect is widely exploited in medicine and industry for cryopreservation of tissues and materials. In view of elucidating molecular mechanisms involved in the interaction of mono- and disaccharides with biomimetic lipid systems, we study the alteration of dielectric properties, the degree of hydration, and the rotational order parameter and dipole potential of lipid bilayers in the presence of sugars. Frequency-dependent deformation of cell-size unilamellar lipid vesicles in alternating electric fields and fast Fourier transform electrochemical impedance spectroscopy are applied to measure the specific capacitance of phosphatidylcholine lipid bilayers in sucrose, glucose and fructose aqueous solutions. Alteration of membrane specific capacitance is reported in sucrose solutions, while preservation of membrane dielectric properties is established in the presence of glucose and fructose. We address the effect of sugars on the hydration and the rotational order parameter for 1-palmitoyl-2-oleoyl-sn-glycero-3- phosphocholine (POPC) and 1-stearoyl-2-oleoyl-sn-glycero-3- phosphocholine (SOPC). An increased degree of lipid packing is reported in sucrose solutions. The obtained results provide evidence that some small carbohydrates are able to change membrane dielectric properties, structure, and order related to membrane homeostasis. The reported data are also relevant to future developments based on the response of lipid bilayers to external physical stimuli such as electric fields and temperature changes.

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Photomanipulation of Minimal Synthetic Cells: Area Increase, Softening, and Interleaflet Coupling of Membrane Models Doped with Azobenzene‐Lipid Photoswitches

Aleksanyan,

Grafmüller,

Crea

et al. 2023

Advanced Science

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Light can effectively interrogate biological systems in a reversible and physiologically compatible manner with high spatiotemporal precision. Understanding the biophysics of photo‐induced processes in bio‐systems is crucial for achieving relevant clinical applications. Employing membranes doped with the photolipid azobenzene‐phosphatidylcholine (azo‐PC), a holistic picture of light‐triggered changes in membrane kinetics, morphology, and material properties obtained from correlative studies on cell‐sized vesicles, Langmuir monolayers, supported lipid bilayers, and molecular dynamics simulations is provided. Light‐induced membrane area increases as high as ≈25% and a ten‐fold decrease in the membrane bending rigidity is observed upon trans‐to‐cis azo‐PC isomerization associated with membrane leaflet coupling and molecular curvature changes. Vesicle electrodeformation measurements and atomic force microscopy reveal that trans azo‐PC bilayers are thicker than palmitoyl‐oleoyl phosphatidylcholine (POPC) bilayers but have higher specific membrane capacitance and dielectric constant suggesting an increased ability to store electric charges across the membrane. Lastly, incubating POPC vesicles with azo‐PC solutions results in the insertion of azo‐PC in the membrane enabling them to become photoresponsive. All these results demonstrate that light can be used to finely manipulate the shape, mechanical and electric properties of photolipid‐doped minimal cell models, and liposomal drug carriers, thus, presenting a promising therapeutic alternative for the repair of cellular disorders.

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Sucrose solutions alter the electric capacitance and dielectric permittivity of lipid bilayers

Cited by 24 publications

References 46 publications

Electromechanical characterization of biomimetic membranes using electrodeformation of vesicles

Electromechanical characterization of biomimetic membranes using electrodeformation of vesicles

Dielectric Properties of Phosphatidylcholine Membranes and the Effect of Sugars

Photomanipulation of Minimal Synthetic Cells: Area Increase, Softening, and Interleaflet Coupling of Membrane Models Doped with Azobenzene‐Lipid Photoswitches

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