Mixed monolayers involving DPPC, DODAB and oleic acid and their interaction with nicotinic acid at the air–water interface
| Autor: | Amélia M.P.S. Gonçalves da Silva, Rute I. S. Romão |
|---|---|
| Rok vydání: | 2005 |
| Předmět: |
1
2-Dipalmitoylphosphatidylcholine Surface Properties Air water interface Analytical chemistry Niacin Biochemistry Miscibility chemistry.chemical_compound symbols.namesake Mixed systems Bromide Monolayer Molecular Biology Microscopy Brewster's angle Air Organic Chemistry Water Membranes Artificial Cell Biology Quaternary Ammonium Compounds Oleic acid Crystallography chemistry Dipalmitoylphosphatidylcholine symbols Thermodynamics lipids (amino acids peptides and proteins) Oleic Acid |
| Zdroj: | Chemistry and Physics of Lipids. 137:62-76 |
| ISSN: | 0009-3084 |
| DOI: | 10.1016/j.chemphyslip.2005.06.004 |
| Popis: | The behaviour of binary mixtures involving dipalmitoylphosphatidylcholine (DPPC), dioctadecyldimethylammonium bromide (DODAB) and oleic acid (OA) was investigated at the air–water interface by surface pressure–area (π–A) measurements and by Brewster angle microscopy (BAM). Thermodynamic analysis indicates for the system DPPC/DODAB miscibility with strong negative deviations from the ideal behaviour, from low to high surface pressures over all the composition range. For systems DODAB/OA and DPPC/OA, thermodynamic analysis and BAM observation indicate miscibility from low to intermediate surface pressures, and phase separation in a limited range of composition at high surface pressures. The interaction of nicotinic acid (NA) with pure lipids and with selected compositions of mixed systems was investigated. Significant positive deviations of π–A isotherms in the presence of NA indicate attractive interactions between NA and the polar groups of DPPC and DODAB. NA easily penetrates in expanded regimes while it tends to be segregated from condensed regimes in mixed monolayers. |
| Databáze: | OpenAIRE |
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