Electric birefringence of surfactant vesicles

Asgharian, Niloofar; Wu, Xiaomao; Meline, Ronald L.; Derecskei, Bela; Cheng, Hanlin; Schelly, Z. A.

doi:10.1016/s0167-7322(97)00044-5

Cited by 12 publications

(17 citation statements)

References 12 publications

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“…The underlying electromechanical deformation of vesicles and the rotational relaxation of the dipoles typically occur on the microsecond time scale. 10,11 Not surprisingly, the nature and dynamics of the overall polarization and deformation processes are similar to those observed in other spheroid organized assemblies such as reverse micelles and water-in-oil microemulsions. 12 Although it is generally known that the experimental parameters must be within certain limits for electroporation to occur * Author to whom correspondence should be addressed.…”

Section: Introductionsupporting

confidence: 63%

Dynamics of Electroporation of Synthetic Liposomes Studied Using a Pore-Mediated Reaction, Ag⁺ + Br^- → AgBr

and

Schelly

1998

J. Phys. Chem. B

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The dynamics of electric field-induced transient pore formation (electroporation) is studied in 178 nm diameter synthetic unilamellar bilayer liposomes, prepared from the surfactant dioleoylphosphatidylcholine (DOPC). With Ag + ions entrapped in the interior compartment of the vesicle and Br -ions placed in the bulk medium, details of the poration process are revealed through the pore-mediated production of (AgBr) n clusters which are detected spectrophotometrically in the UV. The field-induced elongation of the spherical bilayer shells to prolate ellipsoids is monitored through the transient birefringence of the system. Effects of the field strength E, pulse length, and number of the high-voltage square pulses applied are investigated, and threshold values of these parameters necessary for electroporation are established. It is found that polarization and elongation of the liposomes precede pore opening by 30 µs, and that 75% of the entrapped Ag + ions are ejected during a single pulse into the bulk solution, where the indicator reaction Ag + + Br -f AgBr takes place.

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Section: Introductionsupporting

confidence: 63%

Dynamics of Electroporation of Synthetic Liposomes Studied Using a Pore-Mediated Reaction, Ag⁺ + Br^- → AgBr

and

Schelly

1998

J. Phys. Chem. B

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“…16,17 Transient electrooptic birefringence (TEB) studies on surfactant vesicles are reported only scarcely. [18][19][20][21][22] These reports deal with this technique as a rapid and sensitive method to measure the size and the optical polarizability of vesicles. The observation that vesiclessalthough spherical in shapesexhibit orientational birefringence is explained by assuming small departures from true sphericity.…”

Section: Introductionmentioning

confidence: 99%

Electrooptic Behavior and Structure of Novel Polymer−Vesicle Hybrids

et al. 1999

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It has been previously shown that polymerization of styrene in DODAB vesicles gives rise to the formation of unique parachute-like structures in which a polymer bead is confined to the bilayer at one pole of the vesicle. In this paper, quantitative data on the size and the shape of these hybrid particles and of the bare DODAB vesicles are obtained by combination of cryo-TEM, transient electrooptic birefringence (Kerr effect), and dynamic light scattering. Also, this study qualitatively assesses the influence of the confined polymer bead on the electrooptic behavior. It turns out that the presence of the bead gives rise to a special response in the transient electrooptic birefringence, typical of the existence of permanent dipoles. Unlike other vesicles, the DODAB vesicles and the polymer/vesicle hybrids do not display a deformation step in their electrooptic response. As such, these particles act as rigid particles under the action of an electric field. The thermal behavior of the DODAB templates and parachutes is investigated and explained in terms of intrinsic vesicle properties.

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“…The monodispersity of the LUV size achieved through this technique was previously checked. [6,7,37] The unilamellar nature of the pure DOPC vesicles prepared by using the extrusion method [37] was previously confirmed [4,5,7,38] by measuring the extent of quenching by Mn + 2 of their 31 P NMR signals. [39] All samples were used immediately after preparation.…”

Section: Methodsmentioning

confidence: 87%

An Alternative Approach to Quantify Partition Processes in Confined Environments: The Electrochemical Behavior of PRODAN in Unilamellar Vesicles

et al. 2010

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Herein, we investigate the behavior of the electroactive molecular probe 6-propionyl-2-dimethyl amino naphthalene (PRODAN) in large unilamellar vesicles (LUV) formed with the phospholipid 1,2-di-oleoyl-sn-glycero-3-phosphatidylcholine (DOPC) by using cyclic voltammetry (CV). The CV studies in pure water confirm our previous spectroscopic results that PRODAN self-aggregates due to its low water solubility. Moreover, the electrochemical results also reveal that the PRODAN aggregated species are non-electroactive within the studied electrochemical potential region. In DOPC LUV media, the redox behavior of PRODAN shows how the LUV bilayer interacts with PRODAN aggregated species to form PRODAN monomer species. Moreover, the electrochemical response of PRODAN allows us to propose a model for explaining the electrochemical experimental results and--in conjunction with our measurements--for calculating the value of the partition constant (K(p)) of PRODAN between the water and LUV bilayer pseudophases. This value coincides with that obtained through an independent technique. Moreover, our electrochemical model allows us to calculate the diffusion coefficient (D) for the DOPC LUV, which coincides with the D value obtained through dynamic light scattering (DLS). Thus, our data clearly show that electrochemical measurements could be a powerful alternative approach to investigate the behavior of nonionic electroactive molecules embed in a confined environment such as the LUV bilayer. Moreover, we believe that this approach can be used to investigate the behavior of non-optical molecular drugs embedded in bilayer media.

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Electric birefringence of surfactant vesicles

Cited by 12 publications

References 12 publications

Dynamics of Electroporation of Synthetic Liposomes Studied Using a Pore-Mediated Reaction, Ag⁺ + Br^- → AgBr

Dynamics of Electroporation of Synthetic Liposomes Studied Using a Pore-Mediated Reaction, Ag⁺ + Br^- → AgBr

Electrooptic Behavior and Structure of Novel Polymer−Vesicle Hybrids

An Alternative Approach to Quantify Partition Processes in Confined Environments: The Electrochemical Behavior of PRODAN in Unilamellar Vesicles

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Electric birefringence of surfactant vesicles

Cited by 12 publications

References 12 publications

Dynamics of Electroporation of Synthetic Liposomes Studied Using a Pore-Mediated Reaction, Ag+ + Br- → AgBr

Dynamics of Electroporation of Synthetic Liposomes Studied Using a Pore-Mediated Reaction, Ag+ + Br- → AgBr

Electrooptic Behavior and Structure of Novel Polymer−Vesicle Hybrids

An Alternative Approach to Quantify Partition Processes in Confined Environments: The Electrochemical Behavior of PRODAN in Unilamellar Vesicles

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Product

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Dynamics of Electroporation of Synthetic Liposomes Studied Using a Pore-Mediated Reaction, Ag⁺ + Br^- → AgBr

Dynamics of Electroporation of Synthetic Liposomes Studied Using a Pore-Mediated Reaction, Ag⁺ + Br^- → AgBr