Cells electric charge analyses define specific properties for cancer cells activity.

The surface electrical charge of cells is conditioned by the ionic medium in which they are immersed. This charge is specific for each cell type and is especially important in tumour cells because it determines their state of aggregation and their adhesion in the different organs. This study analyses the variations in surface charge of cells when pH, electrolytes, and their concentration are modified. The modification of these factors leads to changes in the surface charge of tumour cells; therefore, their states of aggregation and behaviour can be modified. This may even have a use in the prognosis and treatment of various tumours. Some studies conclude that the activity associated with the glycolysis process is accompanied by a change in the surface charge of cells. Notably, there is a high rate of glycolysis in tumours. Our results show that surface charge of cells strongly depends on nature of ionic medium in which they are found, with the valence of the majority ion being the most important factor. When ionic strength was high, the charge decreased dramatically. On the other hand, charge becomes zero or positive in an acidic pH, while in a basic pH, the negative charge increases.

On the structure of electrical double layer of IgG immobilized on polystyrene microspheres.

Latex particles used in the development of immunoassays usually present stability problems when the antibody is attached to the surface. This work is an attempt to know the potential distribution parameters around these complexes by electrokinetic measurements. The conversion of mobility data into zeta-potential was carried out by different theoretical approaches developed by Smoluchowski (classical equation), O'Brien and White, and Dukhin and Semenikhin. The zeta-potential calculated with allowance for electrical double layer (e.d.l.) polarization was substantially greater than zeta calculated according to the classical electrokinetic theory. The greater values of zeta D-S in comparison with zeta O-W were readily explained on the basis that in the first theory, the contribution to polarization from all ions of the diffuse layer was taken into account, whereas O'Brien and White accounted for only the ions of the hydrodynamically mobile part of the e.d.l. This is an indication that the anomalous surface conductance of latex particles coated by IgG molecules is much higher than that of bare latex particles.