Solubilization of phospholipid/triacylglycerol aggregates by non-ionic surfactants

The aggregates formed by sonication of mixtures of triacylglycerols (trigly cerides) (TG) and egg phosphatidylcholine (EPC) have been examined at 25 de grees C at 6 [TG]/[EPC] ratios ranging from 0 to approximate to 1 (mol/mol) by gel exclusion chromatography and quasi-elastic light scattering. The so lubilization by Triton X-100 of the aggregates formed has been followed at 25 degrees C for different lipid concentrations at each of the 6 [TG]/[EPC] ratios by continuous turbidity monitoring and quasi-elastic light scatteri ng. Analysis of the four steps, separated by three break points, observed o n turbidity curves during the partial solubilization of mixed aggregates in dicated the formation of two types of aggregates, vesicles and emulsion par ticles. These structures were confirmed by cryotransmission electron micros copy. The solubility limit of TG in phosphatidylcholine vesicles was found to be about 3.8 mol%. (C) 1998 Elsevier Science Ireland Ltd. All rights res erved.