Electrochemical Investigation of the Stability of Poly-Phosphocholinated Liposomes.

Poly[2-(methacryloyloxy)ethyl phosphorylcholine] liposomes (pMPC liposomes) gained attention during the last few years because of their potential use in treating osteoarthritis. pMPC liposomes that serve as boundary lubricants are intended to restore the natural lubrication properties of articular cartilage. For this purpose, it is important that the liposomes remain intact and do not fuse and spread as a lipid film on the cartilage surface.

Change in Osmotic Pressure Influences the Absorption Spectrum of Hemoglobin inside Red Blood Cells.

Absorption spectra of red blood cell (RBC) suspensions are investigated in an osmolarity range in the medium from 200 mOsm to 900 mOsm. Three spectral parameters are used to characterize the process of swelling or shrinkage of RBC-the absorbance at 700 nm, the Soret peak height relative to the spectrum background, and the Soret peak wavelength. We show that with an increase in the osmolarity, the absorbance at 700 nm increases and the Soret peak relative height decreases.

Hemolysis by Saponin Is Accelerated at Hypertonic Conditions.

Saponins are a large group of organic amphiphilic substances (surfactants) mainly extracted from herbs with biological activity, considered as one of the main ingredients in numerous remedies used in traditional medicine since ancient times. Anti-inflammatory, antifungal, antibacterial, antiviral, antiparasitic, antitumor, antioxidant and many other properties have been confirmed for some. There is increasing interest in the elucidation of the mechanisms behind the effects of saponins on different cell types at the molecular level.

Effects of divalent cations on the formation and structure of solid supported lipid films.

The interaction of glassy carbon-supported thin wetting films of lecithin with some divalent cations is investigated by impedimetry and voltammetry. The influence of Ca2+, Mg2+, and Mn2+ on the film structure is explored in two different cases--the divalent cations are added to the electrolyte either before or after the formation of the film. When the film has been previously formed, the addition of divalent cations in millimolar concentrations leads to changes in the passive electrical parameters and the blocking properties of the films.

Interaction of thin wetting films of lecithin with some divalent cations.

The impact of some divalent cations on the structure of a model membrane system, comprising wetting lipid films, is assayed in this work. The results from impedimetry suggest prominent structural changes upon the addition of the discussed ions to the electrolyte solution contacting the film. These changes are manifested by the increase of resistivity of the films as well as by the decrease of capacitance dispersion.

Evaluation of chlorophyll fluorescence and membrane injury in the leaves of barley cultivars under osmotic stress.

Two physiological tests for screening drought tolerance of barley (Hordeum vulgare, L.) plants are compared in this work. Water deficit is induced by treating the plants' roots with polyethylene glycol (PEG 8000).

Wetting films of lipids in the development of sensitive interfaces. An electrochemical approach.

Solid-supported thin liquid films of lipids, contacting an electrolyte phase, turned out to be a dependable system in the field of bosensors. The investigations of these objects during the past decade reveal some of their intriguing features enabling the application in constructions of receptor part with 'two-dimensional' arrangement. As a model system, complementary to the other artificial analogs of biomembranes, the wetting films of lipids offer certain advantages concerning the compromise between the stability and flexibility of the molecular structures involved in sensing.

Electrochemical investigations of cholesterol enriched glassy carbon supported thin lipid films.

The formation and study of stable cholesterol enriched thin lipid layers onto the surface of glassy carbon electrode is reported in this work. The method of formation relies on additional thinning of wetting films by electrostriction. Electrochemical techniques based on the concepts of impedance and voltammetry are used to explore the films' features.