Please use this identifier to cite or link to this item: http://repositorio.unicamp.br/jspui/handle/REPOSIP/55479
Type: Artigo de periódico
Title: Binding of chloroquine to ionic micelles: Effect of pH and micellar surface charge
Author: Santos, MDS
Del Lama, MPFD
Ito, AS
Naal, RMZG
Abstract: The pharmacological action of chloroquine relies on its ability to cross biological membranes in order to accumulate inside lysosomes. The present work aimed at understanding the basis for the interaction between different chloroquine species and ionic micelles of opposite charges, the latter used as a simple membrane model. The sensitivity of absorbance and fluorescence of chloroquine to changes in its local environment was used to probe its interaction with cetyltrimethylammonium micelles presenting bromide (CTAB) and sulfate (CTAS) as counterions, in addition to dodecyl sulfate micelles bearing sodium (SDS) and tetramethylammonium (TMADS) counterions. Counterion exchange was shown to have little effect on drug-micelle interaction. Chloroquine first dissociation constant (pKa(1)) shifted to opposite directions when anionic and cationic micelles were compared. Chloroquine binding constants (K-b) revealed that electrostatic forces mediate charged drug-micelle association, whereas hydrophobic interactions allowed neutral chloroquine to associate with anionic and cationic micelles. Fluorescence quenching studies indicated that monoprotonated chloroquine is inserted deeper into the micelle surface of anionic micelles than its neutral form, the latter being less exposed to the aqueous phase when associated with cationic over anionic assemblies. The findings provide further evidence that chloroquine-micelle interaction is driven by a tight interplay between the drug form and the micellar surface charge, which can have a major effect on the drug biological activity. (C) 2013 Elsevier B.V. All rights reserved.
Subject: Chloroquine
SOS micelles
CTAB micelles
Dissociation constants
Binding constants
Steady-state and time-resolved fluorescence quenching
Country: Holanda
Editor: Elsevier Science Bv
Rights: fechado
Identifier DOI: 10.1016/j.jlumin.2013.10.037
Date Issue: 2014
Appears in Collections:Artigos e Materiais de Revistas Científicas - Unicamp

Files in This Item:
There are no files associated with this item.


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