Experimental evidence and physiological significance of the ascorbate passive diffusion through the lipid bilayer.

The diverse range of functions performed by ascorbate in many metabolic processes requires its effective redistribution between various aqueous body compartments. It is believed that this hydrophilic molecule needs protein transporters for crossing the biological membrane barriers. Any effective model reflecting the ascorbate distribution within the body requires bi-directional fluxes, but only the ascorbate transporters facilitating its intake by cells have been identified to date.

Effects of electroformation protocol parameters on quality of homogeneous GUV populations.

Giant unilamellar vesicles (GUVs) have become one of extensively studied biological bilayer models especially when investigating topological and mechanical properties of cell membranes. They are also used to visualize membrane-related phenomena. However, the method of preparation and the effects of parameters of preparation on the vesicular structure are extensively varied.

Alterations of biomechanics in cancer and normal cells induced by doxorubicin.

Mechanical properties of biological structures play an important role in regulating cellular activities and are critical for understanding metabolic processes in cancerous cells and the effects of drugs. For some cancers, such as acute myeloid leukaemia, chemotherapy is one of preferential methods. However, due to the lack of selectivity to cancer cells, cytostatic agents cause toxicity to normal tissues.

Changes in lipid membrane mechanics induced by di- and tri-phenyltins.

Organotin compounds, being biologically active, affect a variety of cellular functions due to their ability to accumulate in and penetrate biological membranes. These compounds influence the distribution of electrostatic charges, alter organization, disrupt molecular dynamics and change mechanical properties of biological membranes. It was found that the membrane/water partition coefficient equals 4, a value significantly higher than octanol/water partition coefficient.

The Effect of a Fluorophore Photo-Physics on the Lipid Vesicle Diffusion Coefficient Studied by Fluorescence Correlation Spectroscopy.

Fluorescence Correlation Spectroscopy (FCS) is a technique, which allows determination of the diffusion coefficient and concentration of fluorescent objects suspended in the solution. The measured parameter is the fluctuation of the fluorescence signal emitted by diffusing molecules. When 100 nm DOPC vesicles labeled with various fluorescent dyes (Fluorescein-PE, NBD-PE, Atto488 DOPE or βBodipy FL) were measured, different values of diffusion coefficients have been obtained.

The modified fluorescence based vesicle fluctuation spectroscopy technique for determination of lipid bilayer bending properties.

Lipid bilayer is the main constitutive element of biological membrane, which confines intracellular space. The mechanical properties of biological membranes may be characterized by various parameters including membrane stiffness or membrane bending rigidity, which can be measured using flicker noise spectroscopy. The flicker noise spectroscopy exploits the spontaneous thermal undulations of the membrane.

Effect of monovalent anions on water transmembrane transport.

Biological structures consist of lipid bilayers immersed in the aqueous phase. They can be considered as a two-phase system where the two phases are separated (connected) by the transition regions (interphases), which properties are affected by both lipid and aqueous phases. Interphase structure and dynamics might influence properties and/or functioning of the lipid bilayer core, including osmotically induced water flow.

The effect of lipid oxidation on the water permeability of phospholipids bilayers.

The effect of lipid oxidation on water permeability of phosphatidylcholine membranes was investigated by means of both scattering stopped flow experiments and atomistic molecular dynamics simulations. Formation of water pores followed by a significant enhancement of water permeability was observed. The molecules of oxidized phospholipids facilitate pore formation and subsequently stabilize water in the membrane interior.

Fluorescence techniques for determination of the membrane potentials in high throughput screening.

The characterization of small molecules requires identification and evaluation of several predictive parameters, when selecting compounds for pharmacological applications and/or determining their toxicity. A number of them are correlated with the compound interaction with biological membranes and/or capacity to cross them. The knowledge of the extent of adsorption, partition coefficient and permeability along with the compound ability to alter membrane properties are critical for such studies.

A method to evaluate a propidium iodide association with oligonucleotides and oligonucleotide-cationic lipid interactions.

Complex molecular ensembles are frequently considered an element of new pharmacological formulations. This is especially evident in the therapies based on genetic information. In order to obtain an effective drug, it is necessary to associate a nucleic acid molecule with the components to ensure the desired aggregate structure and properties.

Application of liposome based sensors in high-throughput screening systems.

High throughout screening is an approach based on the concept which assumes that when sufficiently large library of compounds are tested, the chance of discovering a new active compound is increased. In order to meet this expectation, proper testing criteria need to be devised. Those criteria should be related to the fate of a compound in the organism to have any predictive power.

A fluorescence method for determining transport of charged compounds across lipid bilayer.

There is a constant need for simple, economical and time-efficient methods which allow evaluating a compound's ability to penetrate the biological membrane, one of the key parameters needed to characterize biologically active compounds. In the paper we propose a new method of permeability determination. Instead of detecting the compound's concentration directly, we employ an approach in which the membrane interface is labeled with a fluorescein lipid probe; the probe is sensitive to the presence of charged compounds.