Variations in the Size and zeta-Potential of Phosphatidylcholine Liposomes with Incorporated Nutriceuticals in the Course of their Initiated Oxidation

摘要

Phosphatidylcholine (PC) liposomes are widely used as models of living cell biomembranes for studying various biochemical processes proceeding in them, in particular, lipid peroxidation (LPO) and effects of different substances on this process. In this work, dynamic light scattering has been employed to study the dynamics of variations in the sizes and zeta-potentials of soybean PC liposomes during their oxidation at 37 degrees C initiated by 2,2'-azobis(amidinopropane) dihydrochloride. The effects of alpha-linoleic acid and carnation essential oil incorprated into the liposomes, as well as the encapsulation of the liposomes with sodium caseinate, on these parameters have been investigated. It has been found that the average size of PC liposomes increases by 6-7% in the course of oxidation; however, no correlation between their sizes and accumulation of LPO products has been revealed. By the end of the oxidation, the absolute value of the zeta potential increases by three times. The inclusion of alpha-linoleic acid into liposomes substantially changes the dynamics of variations in their sizes and zeta potential. The presence of carnation essential oil in liposomes decreases the accumulation of conjugated dienes during the oxidation and stabilizes the sizes and zeta-potentials by the end of oxidation for both original liposomes and liposomes containing alpha-linoleic acid. Encapsulation of liposomes with sodium caseinate stabilizes the sizes and zeta-potentials of complex structures formed in the course of oxidation.