Neat DODAB vesicles: Effect of sonication time on the phase transition thermodynamic parameters and its relation with incomplete chain freezing

• Type: Article in International Scientific Journal
• Date: 2005

Authors

Brito, RO (Author) Other; Marques, EF (Author) FCUP

Journal

Title: Chemistry and Physics of Lipids

Vol. 137

Pages: 18-28

ISSN: 0009-3084

Publisher: Elsevier

Indexing

ISI Web of Knowledge - 47 Citations

Scopus - 48 Citations

Scientific classification

FOS: Natural sciences > Biological sciences

Other information

Authenticus ID: P-000-10A

DOI: 10.1016/j.chemphyslip.2005.05.001

Abstract (EN): Vesicle solutions formed by the cationic lipid dioctadecyldimethylammonium bromide have been extensively used in the past 20 years as model membrane systems. Often, discrepancies are found in the literature for the thermodynamic parameters of the gel-to-liquid crystal (gel-lc) phase transition of these vesicles. In this work we present a systematic DSC investigation on the influence of the sonication method on the main temperature and enthalpy of the transition for DODAB vesicles, prepared both in normal and deuterated water. It is shown that as the sonication time increases, the T-m and enthalpy values decrease until a plateau value is reached. This effect is associated with incomplete chain crystallization in the highly curved vesicles (produced by sonication) when they are cooled below the transition temperature. The effect of aging on the sonicated solutions has also been monitored by DSC.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 11