Effect of Different Anions on 22Na Permeability of Liposomes

1973 ◽  
Vol 51 (11) ◽  
pp. 779-784 ◽  
Author(s):  
M. A. Singer
Keyword(s):  
Zeta Potential ◽  
Dipole Potential ◽  
Sodium Permeability ◽  
Phosphatidylcholine Liposomes ◽  
Solution Interface ◽  
Cation Permeability ◽  
Na Efflux ◽  
Negative Zeta Potential

The 22Na efflux from phosphatidylcholine liposomes was measured in the presence of different anions. Only salicylate significantly increases sodium permeability. Although this anion adsorbs onto the liposomal surface creating a negative zeta potential, evidence is presented that this is not the sole mechanism underlying the enhanced cation permeability. It is proposed that salicylate also alters the dipole potential at the membrane–solution interface.

scholarly journals Adsorption of malic acid at the hydroxyapatite/aqueous NaCl solution interface

2021 ◽  
Author(s):  
Władysław Janusz ◽  
Ewa Skwarek
Keyword(s):  
Zeta Potential ◽  
Malic Acid ◽  
Particle Sizes ◽  
Nacl Solution ◽  
X Ray Diffraction ◽  
Radioisotope Method ◽  
X Ray ◽  
Solution Interface ◽  
Adsorption Desorption ◽  
Kinetics Of

AbstractThe aim of the study was the basic incidence on the phenomenon of adsorption that occurs at the hydroxyapatite/malic acid interface, leading to a change in the surface properties of hydroxyapatite, Analytical methods used in the research: X-ray diffraction (XRD) as well as by the, adsorption–desorption of nitrogen (ASAP), potentiometric titration. The specific adsorption of malic acid ions at the hydroxyapatite interface was investigated by means of the radioisotope method. The zeta potential of hydroxyapatite dispersions was determined by electrophoresis with Zetasizer Nano ZS90 by Malvern. The particle sizes of hydroxyapatite samples were analyzed using Masteriszer 2000 Malvern. Studies on the kinetics of malic acid on hydroxyapatite from a solution with an initial concentration of 1 mmol/dm3 have shown that the adsorption process is initially fast, followed by a slow adsorption step. An increase in the pH of the solution causes a decrease in the malic acid adsorption as a result of competition with hydroxyl ions. The presence of adsorbed malic acid was confirmed by the FTIR measurements. The effect of malic acid adsorption on the zeta potential and particle size distribution of hydroxyapatite in the NaCl solution was investigated.

Influence of Surface Zeta Potential on Adhesion of Chlorella sp. to Substratum Surfaces

2013 ◽  
Vol 690-693 ◽  
pp. 1431-1434
Author(s):  
Xin Ru Zhang ◽  
Ze Yi Jiang ◽  
Hao Yuan ◽  
Yuan Xiang Lu ◽  
Liang Chen ◽  
...  
Keyword(s):  
Zeta Potential ◽  
Cell Surface ◽  
Mass Culture ◽  
Chlorella Sp ◽  
Microalgae Mass Culture ◽  
Negative Zeta Potential

Microalgae, in wet conditions, tend to grow on surfaces and form biofilms. The adhesion of microalgae to surfaces is very important for algal mass culture. The formation and development of microalgal biofims are in large denpend on the properties of cell surface, substratum surface and gowth medium. In this paper, the influence of substratum surface zeta potential on the microalgal biofilms was particularly investigated. We focused on a widely-used microalgal strain, the freshwater autotrophicChlorella sp..The adhesion phenomena ofChlorella sp.to surfaces with different zeta potential were observed microscopically. It was found thatChlorella sp.adhered easily to the surface with a positive zeta potential and difficultly to the surface with a negative zeta potential. We concluded that the surface zeta potential had a greater influence on the adhesion of microalgal cells to substratum surfaces. Our findings have important implications for microalgae mass culture and harvesting.

Enhanced growth and matrix production by human osteoblastic cells cultured on biomaterials with negative zeta potential

Bone ◽  
2009 ◽  
Vol 44 ◽  
pp. S259 ◽  
Author(s):  
J.P. Dillon ◽  
P.J.M. Wilson ◽  
W.D. Fraser ◽  
B.K. Mwaura ◽  
M.J. Hayton ◽  
...  
Keyword(s):  
Zeta Potential ◽  
Osteoblastic Cells ◽  
Matrix Production ◽  
Human Osteoblastic Cells ◽  
Negative Zeta Potential ◽  
Cells Cultured

Bioleaching Solutions Used for the Nanoparticles Biosynthesis for Uranium and Arsenic Immobilization

2020 ◽  
Vol 304 ◽  
pp. 45-50
Author(s):  
Agnieszka Pawlowska ◽  
Zygmunt Sadowski
Keyword(s):  
Zeta Potential ◽  
Solid Waste ◽  
Green Tea ◽  
Camellia Sinensis ◽  
Plant Extract ◽  
Uranium Dioxide ◽  
Electrical Potential ◽  
Nanoparticle Synthesis ◽  
Negative Zeta Potential

Bioleaching solutions from uranium and arsenic solid waste served as a source of U(VI) and As (V) ions, while plant extract from green tea (Camellia sinensis) – as a reductor for nanoparticle synthesis. Uranium dioxide and As (III) nanoparticles were formed as a product of bioreduction on the hematite and schwertmannite surfaces respectively, which resulted in an increase in the negative zeta potential with an increase in pH. It suggests, that the electrical potential depends on the presence of nanoparticles. The SEM microphotographs revealed the UO2 nanoparticles on the hematite surface.

scholarly journals Studies of Some Properties and the Structure of Polyethylene Glycol (PEG) Macromolecules Adsorbed on a TiO2 Surface

2001 ◽  
Vol 19 (5) ◽  
pp. 397-407 ◽  
Author(s):  
S. Chibowski ◽  
M. Paszkiewicz
Keyword(s):  
Molecular Weight ◽  
Polyethylene Glycol ◽  
Zeta Potential ◽  
Surface Charge ◽  
Adsorption Layer ◽  
Bulk Solution ◽  
Ionic Structure ◽  
Solution Interface ◽  
Main Factors ◽  
Presence And Absence

In the studies presented, the influence of the molecular weight of polyethylene glycol (PEG) on the adsorption and electrical properties at the metal oxide/polymer solution interface has been determined. The main factors responsible for the observed changes in the zeta potential and surface charge of titania were determined on the basis of the data obtained. It was demonstrated that changes in the ionic structure of the Stern layer depend on the molecular weight of PEG and its conformation. A possible mechanism for the changes in zeta potential both with pH and molecular weight was proposed on the basis of values of the surface charge difference (Δσ0) and the diffuse layer charge difference (Δσd) as determined in the presence and absence of the polymer. The thickness of the adsorption layer (δ) on the surface of titania was calculated from the zeta potential changes, both in the presence and absence of the polymer. A distinct influence of the PEG molecular weight was noted on the values of the adsorption layer thickness (δ) determined. The structures of the macromolecules in solution and at the solid/solution interface were compared and from the dependencies obtained some changes in the shape and dimensions of the polymer coils on passing from the bulk solution to the interface were proposed.

Tumor Targeting of Plasmid DNA by Dextran Conjugation Based on Metal Coordination

2005 ◽  
Vol 288-289 ◽  
pp. 109-112
Author(s):  
H. Hosseinkhani ◽  
T. Aoyama ◽  
O. Ogawa ◽  
Yasuhiko Tabata
Keyword(s):  
Gene Expression ◽  
Zeta Potential ◽  
Plasmid Dna ◽  
Tumor Targeting ◽  
Metal Coordination ◽  
Hydroxyl Groups ◽  
Negative Zeta Potential

Tumor targeting of plasmid DNA was achieved through the conjugation of dextran derivative with chelate residue based on metal coordination. Spermine (Sm) was chemically introduced to the hydroxyl groups of dextran to obtain dextran-Sm derivative. A negative zeta potential of plasmid DNA became almost 0 mV by the Zn2+-coordinated conjugation with the dextran-Sm When the dextran-Sm-plasmid DNA conjugate with Zn2+ coordination was intravenously injected to mice subcutaneously bearing Meth-AR-1 fibrosarcoma, the dextran- Sm-plasmid DNA conjugate significantly enhanced the level of gene expression in the tumor, in contrast to free plasmid DNA..

Ion movements in membrane vesicles: a new fluorescence method and application to smooth muscle

1985 ◽  
Vol 248 (3) ◽  
pp. C372-C378 ◽  
Author(s):  
A. K. Grover ◽  
A. P. Singh ◽  
P. K. Rangachari ◽  
P. Nicholls
Keyword(s):  
Membrane Potential ◽  
Membrane Permeability ◽  
Membrane Vesicles ◽  
Liposomal Membrane ◽  
Phosphatidylcholine Liposomes ◽  
Permeability Characteristics ◽  
Cation Permeability ◽  
Ion Movements ◽  
Rate Of Dissipation ◽  
Very High

A method is described for studying ion permeabilities of membrane vesicles based on the principle that when membrane permeability to H+ is very high, the H+ movement is determined by the membrane potential generated by the H+ movement. The rate of H+ movement under these conditions thus gives a measure of the rate of dissipation of this membrane potential by comovement of anions or countermovement of cations present. Thus, by studying the H+ efflux using an impermeant cation and different anions, the membrane permeability to the anions can be assessed. Similarly, the use of an impermeant anion allows the study of the permeation of various cations. H+ movement was followed across the membranes by monitoring a change in the fluorescence intensity of the pH-sensitive dye pyranine trapped inside the membranes. This method when tested using phosphatidylcholine liposomes yielded the expected results, i.e., permeability of the liposomal membrane was: Cl- greater than SO2-4 and K+ greater than Na+. A plasma membrane-enriched fraction loaded with pyranine was isolated from estrogen-dominant rat myometrium. The anion permeability characteristics of this membrane were studied using tetramethylammonium (TMA+) as the poorly permeant cation, and the cation permeability was studied using L-glutamate- as the poorly permeant anion. The anion permeabilities were D-glutamate- less than L-glutamate- less than glutarate2- less than Cl- less than or equal to SO2-4, and the cation permeabilities were TMA+ less than K+ less than Na+. It is hypothesized that the observed anomalously higher Na+ and SO2-4 movements may involve special mechanisms.

scholarly journals In Vitro and Ex Vivo Evaluation of Nepafenac-Based Cyclodextrin Microparticles for Treatment of Eye Inflammation

Nanomaterials ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 709 ◽  
Author(s):  
Blanca Lorenzo-Veiga ◽  
Patricia Diaz-Rodriguez ◽  
Carmen Alvarez-Lorenzo ◽  
Thorsteinn Loftsson ◽  
Hakon Hrafn Sigurdsson
Keyword(s):  
Zeta Potential ◽  
Physicochemical Properties ◽  
Inflammatory Mediators ◽  
Ex Vivo ◽  
Posterior Segment ◽  
Inflammatory Activity ◽  
Commercial Formulation ◽  
Anti Inflammatory ◽  
Negative Zeta Potential

The aim of this study was to design and evaluate novel cyclodextrin (CD)-based aggregate formulations to efficiently deliver nepafenac topically to the eye structure, to treat inflammation and increase nepafenac levels in the posterior segment, thus attenuating the response of inflammatory mediators. The physicochemical properties of nine aggregate formulations containing nepafenac/γ-CD/hydroxypropyl-β (HPβ)-CD complexes as well as their rheological properties, mucoadhesion, ocular irritancy, corneal and scleral permeability, and anti-inflammatory activity were investigated in detail. The results were compared with a commercially available nepafenac suspension, Nevanac® 3 mg/mL. All formulations showed microparticles, neutral pH, and negative zeta potential (–6 to –27 mV). They were non-irritating and nontoxic and showed high permeation through bovine sclera. Formulations containing carboxymethyl cellulose (CMC) showed greater anti-inflammatory activity, even higher than the commercial formulation, Nevanac® 0.3%. The optimized formulations represent an opportunity for topical instillation of drugs to the posterior segment of the eye.

scholarly journals Design of dispersant for highly concentrated one-dimensional Nb2Se9 inorganic molecular chains from bulk crystal

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Sudong Chae ◽  
Akhtar J. Siddiqa ◽  
Seungbae Oh ◽  
Bum Jun Kim ◽  
Kyung Hwan Choi ◽  
...  
Keyword(s):  
Charge Transfer ◽  
Zeta Potential ◽  
Steric Hindrance ◽  
Bulk Crystal ◽  
One Dimensional ◽  
1D Chain ◽  
A Charge ◽  
Negative Zeta Potential ◽  
Octadecyl Amine

Abstract We determined the optimum dispersant to separate bulk Nb2Se9 material into 1D chain units. The Nb2Se9, which had a negative zeta potential (−43.3 mV), showed acidic characteristics and strongly bonded with the amine head of octadecyl amine through a charge transfer (from the amine to Se atoms) reaction. The steric hindrance of the octadecyl tail resulted in excellent dispersion of Nb2Se9 (down to nanometre-sized mono-chains).

Use of Malonic Acid in Chemical-Mechanical Polishing ( CMP ) of Tungsten

1997 ◽  
Vol 477 ◽  
Author(s):  
L. Zhang ◽  
S. Raghavan
Keyword(s):  
Zeta Potential ◽  
Malonic Acid ◽  
Chemical Mechanical Polishing ◽  
Mechanical Polishing ◽  
Small Scale ◽  
Ph Values ◽  
Particulate Contamination ◽  
Principal Objective ◽  
Alumina Particles ◽  
Negative Zeta Potential

ABSTRACTThe use of malonic acid as an additive in alumina slurries used for the chemical mechanical polishing ( CMP ) of tungsten has been explored for the reduction of particulate contamination. The principal objective of this work was to delineate conditions under which alumina contamination on polished surfaces could be reduced.The interaction between malonic acid and alumina particles has been investigated through electrokinetic and adsorption measurements. At suitable malonic acid concentrations and pH values, tungsten and alumina surfaces develop a negative zeta potential resulting in conditions conducive to reduced particulate contamination. Small scale polishing experiments have been carried out to relate electrokinetic results to the level of particulate contamination after polishing.

Sign in / Sign up

Export Citation Format

Share Document