EFFECT OF STEROL DERIVATIVES ON NATURAL PHOSPHOLIPID WITHIN LIPID BILAYER MEMBRANE

EFFECT OF STEROL DERIVATIVES ON NATURAL PHOSPHOLIPID WITHIN LIPID BILAYER MEMBRANE

This study investigated the physicochemical characteristics of vesicles that were prepared from two phosphatidylcholines andthree sterol derivatives (SD) with different hydrophilic head groups, by measuring particle size and zeta potential. The aim was tofurther investigate the interaction between saturated and unsaturated phosphatidylcholine mixtures of SD and their storage stability.Results obtained from dynamic light scattering (DLS), zeta potential and transmission electron microscopy (TEM) show thatspherical and/or angular vesicles of phosphatidylcholine/SD can be formed by self-assembly in aqueous solutions. Theexperimental data reveal that the incorporation of SD into lipid vesicles causes significant changes in the size, zeta potential, storagestability, and membrane fluidity of colloids, which may be correlated with the structure of the SD, the degree of saturation of thelipids, and the vesicular composition. The phosphatidylcholine/NaDC vesicles showed a smaller particle size and higher negativezeta potential. Furthermore, characteristics of vesicles dispersed in water were studied by differential scanning calorimetry (DSC)and fluorescence polarization. The phosphatidylcholine/NaDC vesicles showed a lower main transition temperature, enhancedmembrane fluidity, and better storage stability. The information obtained from these studies may be useful for the design of noveldrug carrier systems.