0000000000061761
AUTHOR
Marian Podolak
showing 7 related works from this author
ESR study of the liposome membrane physical parameters in the heating-cooling cycles.
1998
Abstract Changes of dynamic and structural parameters of egg yolk lecithin (EYL) liposome membranes in the heating-cooling cycles have been studied using the E S R spin probe method. The investigations were conducted in the range of temperatures from -18 °C to +60 °C. It has been found that in the range of temperatures -15 °C to +45 °C in both the heating and the cooling run the spectroscopic parameters changed practically along the same curve (reversible changes). However, after exceeding this range of temperatures one of the parameters (partition coefficient of the spin probe 2,2,6,6 -tetramethylpiperidine -1-oxyl; TEMPO) changed along a closed curve, showing the phenomenon of thermal h…
Effect of Chlorotriphenyl Derivatives of Sn and Pb upon Biophysical Properties of Membranes
2009
Biophysical activity of two twin organometallic compounds Triphenyltin chloride (TPhT) and Triphenyllead chloride (TPhL) in their interreaction with model membranes, as well as with yeast cellsSaccharomyces cerevisiae, was investigated. Four measurement methods were used in the experiments: two physical methods (spin probes method and the electric method); two biological methods (minimal inhibitory concentration /MIC/ and yeast survival test). It has been found that the activity of TPhT in interaction with model membranes and yeast cells is distinctly greater than that of TPhL. The activity manifests itself by considerable increase in the fluidity of the middle part of liposome bilayer, cha…
Tin compounds interaction with membranes of egg lecithin liposomes.
2007
This work is a continuation of earlier research concerning the influence of tin compounds on the dynamic properties of liposome membranes produced with lecithin hen egg yolks (EYL). The experiments were carried out at room temperature (about 25 ∞C). Four tin compounds were chosen, including three organic ones, (CH3)4Sn, (C2H5)4Sn and (C3H7)3SnCl, and one inorganic, SnCl2. The investigated compounds were admixed to water dispersions of liposomes. The content of the admixture changed within the range 0 mol-% to 11mol-% in proportion to EYL. Two spin probes were used in the experiment: 2,2,6,6-tetramethylpiperidine- 1-oxyl (TEMPO) and 2-ethyl-2-(15-methoxy-15-oxopentadecyl)-4,4-dimethyl-3-oxaz…
Effect of Organic Tin Compounds on Electric Properties of Model Membranes
2006
The objective of the present work was to investigate the effect of selected organic tin compounds and potassium chloride (used as a reference substance) on the trans-membrane electric voltage and electric resistance of model membranes, the latter being nitrocellulose filters impregnated with butylene ester of lauric acid. The increasing KCl concentration (in the measurement chambers) caused a rapid rise of the negative trans-membrane voltage, whose value stabilized afterwards. In the case of (C3H7)3SnCl an abrupt maximum of the negative voltage was observed followed by a monotonic drop to zero. In the case of highest concentrations of this compound the voltages, after having reached zero, c…
Bimodal Effect of Amphiphilic Biocide Concentrations on Fluidity of Lipid Membranes
1996
Abstract Using the spin label method (ESR) it has been shown that biologically active, amphiphilic compounds (quaternary ammonium salts -AS) containing polar heads with single and double positive charge caused, at low concentrations, decrease fluidity of liposome membranes formed with egg yolk lecithin (EYL). At higher concentrations an increase in fluidity was observed. With compounds having a single positive charge minimum fluidity of membrane structure occurs in the range of 1 to 3%, with compounds containing double positive charge -in the range of 4 -6 % . That effect does not depend on polar head size and length of alkyl chains of the AS used. Analysis of the electrostatic interaction …
The influence of tin compounds on the dynamic properties of liposome membranes: A study using the ESR method
2005
AbstractThe influence of organic and inorganic compounds of tin on the dynamic properties of liposome membranes obtained in the process of dipalmitoylphosphatidylcholine (DPPC) sonication in distilled water was investigated. This was carried out by means of the spin ESR probe method. The probes were selected in such a way as to penetrate different areas of the membrane (a TEMPO probe, 5-DOXYL stearic acid, 16-DOXYL stearic acid). Four compounds of tin were chosen: three organic ones, (CH3)4Sn, (C2H5)4Sn and (C3H7)3SnCl, and one inorganic one, SnCl2. The investigated compounds were added to a liposome dispersion, which was prepared prior to that. The concentration of the admixture was change…
Computer Simulations of the Electric Interactions between the Phospholipid Head-Groups and Ionic Admixtures in the Membrane Surface
2001
Some phospholipids (e.g. lecithin) form a system of electric dipoles on the membrane surface layer. In the case of lecithin the positive dipole charge is located on the choline and the negative one on the phosphoric molecule group. These dipoles are arranged almost parallel to the membrane surface. Taking the dipole membrane structure as a base for further investigations, a computer model of the electrostatic interaction between the dipole system and the ionic admixture was investigated. The model presumes hexagonal centered or a rectangular flat geometry of the 121 dipoles distribution. The dipoles may rotate freely around round the motionless symmetry axis perpendicular to the system surf…