On the Formation of Discoidal versus Threadlike Micelles in Dilute Aqueous Surfactant/Lipid Systems
| Autor: | Maria C. Sandström, Magnus Bergström, Katarina Edwards, Emma Johansson |
|---|---|
| Rok vydání: | 2008 |
| Předmět: |
Ether
Polyethylene glycol Mixed micelle Micelle Polyethylene Glycols Surface-Active Agents chemistry.chemical_compound Microscopy Electron Transmission Pulmonary surfactant Sodium sulfate Electrochemistry Organic chemistry General Materials Science Micelles Spectroscopy Phosphatidylethanolamine Aqueous solution Phosphatidylethanolamines technology industry and agriculture Water Surfaces and Interfaces Condensed Matter Physics Lipids chemistry Chemical engineering lipids (amino acids peptides and proteins) |
| Zdroj: | Langmuir. 24:1731-1739 |
| ISSN: | 1520-5827 0743-7463 |
| DOI: | 10.1021/la702637h |
| Popis: | In a recent study, we showed that the surfactant 1,2-distearoyl-sn-glycero-3-phosphatidylethanolamine-N-[methoxy(polyethylene glycol)-2000 (DSPE-PEG2000) induced mixed micelles of either threadlike or discoidal shape when mixed with different types of lipids. In this study, we have exchanged the PEG-lipid for the more conventional surfactants octaethylene glycol monododecyl ether (C12E8), hexadecyltrimethylammonium bromide (CTAB), and sodium dodecyl sulfate (SDS). Cryo-TEM investigations show that also these surfactants are able to induce the formation of long-lived discoidal micelles. Generally, the preference for either discoidal or threadlike micelles can be tuned by the choice of lipids and environmental conditions in much the same way as observed for the lipid/PEG-lipid system. Our investigation showed, furthermore, that the choice of surfactant may influence the type of mixed micelles formed. It is argued that the formation of discoidal rather than threadlike micelles may be rationalized as an effect of increasing bending rigidity. Our detailed theoretical model calculations show that the bending rigidity becomes significantly raised for aggregates formed by an ionic rather than a nonionic surfactant. |
| Databáze: | OpenAIRE |
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