Abstract

Purpose: To study the micelle-to-vesicle transformation by detergent removal using adsorption onto polystyrene bio-beads SM2. Methods: A mixed micelle solution (egg yolk phosphatidylcholine (EggPC)-detergent) was passed through a column packed with bio-beads SM2. After each passage, the apparent particle size, turbidity, and freeze-fracture electron microscopy image of aggregates of EggPC-detergent were examined. Results: The turbidity and apparent particle size patterns of the EggPC-3-[(3-cholamidopropyl)dimethylammonio]-1-propanesulfonate (CHAPS) system were significantly increased compared with those of the EggPC-sodium taurocholate (TC) system during detergent removal. The worm-like micelles and rod-like micelles were predominant intermediate structures during TC removal. The rod-like micelles accounted for the majority of intermediate structures during CHAPS removal. The removal of TC led to the formation of small unilamellar vesicles (SUVs). However, large unilamellar vesicles (LUVs) were obtained when CHAPS was removed. Conclusion: The type of detergent is one of the factors determining the ultimate size of vesicles during micelle-to-vesicle transformation.


Keywords:  Micelle-to-vesicle transformation   Vesicle formation   CHAPS   EggPC   Sodium taurocholate   Bio-beads SM2