Mixed monolayer of DPPC and lysine-based cationic surfactants: An investigation into the antimicrobial activity

In this paper, we report studies which aim to elucidate the mechanisms involved in the antimicrobial activity of three cationic lysine-based surfactants: LLM, LALM, and C6 (LL)2. To this end, a simple membrane model (i.e., 1,2-dipalmitoyl-sn-phosphatidylcholine, DPPC) was used to explore the monolay...

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Detalles Bibliográficos
Autores: Colomer, Aurora, Pérez, Lourdes, Pons Pons, Ramon, Infante, María Rosa, Pérez-Clos, Daniel, Manresa, Ángeles, Espuny, María José, Pinazo Gassol, Aurora
Tipo de recurso: artículo
Estado:Versión aceptada para publicación
Fecha de publicación:2013
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/128681
Acceso en línea:http://hdl.handle.net/10261/128681
Access Level:acceso abierto
Palabra clave:Anti-microbial activity
Cell destruction
Hydrophobic interactions
Membrane models
Mixed monolayers
Staphylococcus aureus
Structural alterations
Surfactant structure
Descripción
Sumario:In this paper, we report studies which aim to elucidate the mechanisms involved in the antimicrobial activity of three cationic lysine-based surfactants: LLM, LALM, and C6 (LL)2. To this end, a simple membrane model (i.e., 1,2-dipalmitoyl-sn-phosphatidylcholine, DPPC) was used to explore the monolayer properties at the air/liquid interface. Compression π-A isotherms of mixtures of DPPC/lysine surfactants at different pH showed an expansion of the DPPC monolayer, suggesting cationic lysine surfactant/DPPC interactions, which strongly depend on surfactant structure and hydrophobic interactions. Antimicrobial activity of the three surfactants has also been assessed with transmission electron microscopy, observing the effects on Staphylococcus aureus and Escherichia coli. The three surfactants caused various kinds of damage to the bacteria tested, such as structural alterations, leakage of internal material, and cell destruction.