Please use this identifier to cite or link to this item: https://hdl.handle.net/10216/97185
Author(s): Joao A S Almeida
Eduardo F Marques
Amalia S Jurado
Alberto A C C Pais
Title: The effect of cationic gemini surfactants upon lipid membranes. An experimental and molecular dynamics simulation study
Issue Date: 2010
Abstract: Gemini surfactants possess interesting interfacial and aggregation properties that have prompted comprehensive studies and successful applications in a wide variety of fields. However, a systematic study on the effect of gemini tail and spacer length upon the organization of lipid membranes has not been presented so far. In this study, we analyze the action of dicationic alkylammonium bromide gemini surfactants on DPPC liposomes, the latter employed as a model of lipid membranes. Differential scanning calorimetry results indicate that the surfactants presenting shorter tails (12 carbons) induce a decrease in the overall order of the bilayer, while those with longer tails (16 and 18 carbons) lead to the formation of more ordered structures. The respective influence on the degree of lipid order transverse to the bilayer was additionally studied resorting to a detailed fluorescence anisotropy study. In this case, it is observed that among the shorter tail surfactants, those with longer spacers (6 and 10 carbons) are responsible for a more pronounced disrupting effect upon the membrane, especially close to the lipid polar heads. Molecular dynamics simulation supports the most important findings and provides insight into the mechanism that governs this interaction. Accordingly, the interplay between tail and spacer length accounts for the differential vertical positioning of the gemini molecules and atom-density in the core of the bilayer, that provide a rationale for the experimental observations.
Subject: Química das superfícies, Espectroquímica, Química aplicada, Química computacional, Química
Surface chemistry, Spectrochemistry, Applied chemistry, Computational chemestry, Chemical sciences
Scientific areas: Ciências exactas e naturais::Química
Natural sciences::Chemical sciences
URI: https://repositorio-aberto.up.pt/handle/10216/97185
Document Type: Artigo em Revista Científica Internacional
Rights: restrictedAccess
Appears in Collections:FCUP - Artigo em Revista Científica Internacional

Files in This Item:
File Description SizeFormat 
48209.pdf
  Restricted Access
2.45 MBAdobe PDF    Request a copy from the Author(s)


Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.