title: Interaction of non-aqueous dispersions of silver nanoparticles with cellular membrane models.
abstract: In this work, silver nanoparticles (AgNPs) dispersed in non-aqueous media and stabilized with polyether block polymers amide (PEBA) were incorporated in Langmuir monolayers of dipalmitoylphosphatidylcholine (DPPC), which served as a cell membrane model. The AgNPs presented surface activity, disturbing the viscoelastic properties of the floating film. They expanded the monolayers decreasing their surface elasticity as observed with surface pressure-area isotherms. Polarization modulation reflection-absorption spectroscopy showed that the permanence of AgNPs at the air-water interface is favored by PEBA, affecting both the hydrophilic and the hydrophobic groups of the phospholipid. Brewster angle microscopy showed that the AgNPs lead to the formation of aggregates at the air-water interface, establishing domains that shear with each other due to the low lateral viscosity of irregular and non-monomolecular domains. These data can be correlated to the possible toxicity and microbicide effect of AgNPs in lipidic surfaces such as in mammalian and microbial membranes.
authors.affiliation: Department of Chemistry, Institute of Environmental, Chemical and Pharmaceutical Sciences, Federal University of São Paulo (UNIFESP), Diadema, SP, Brazil.
authors.forename: Gustavo Bonomi
authors.initials: GB
authors.lastname: Soriano
authors.affiliation: Department of Chemistry, Institute of Environmental, Chemical and Pharmaceutical Sciences, Federal University of São Paulo (UNIFESP), Diadema, SP, Brazil.
authors.forename: Roselaine
authors.initials: R
authors.lastname: da Silva Oliveira
authors.affiliation: Department of Chemistry, Institute of Environmental, Chemical and Pharmaceutical Sciences, Federal University of São Paulo (UNIFESP), Diadema, SP, Brazil.
authors.forename: Fernanda Ferraz
authors.initials: FF
authors.lastname: Camilo
authors.affiliation: Department of Chemistry, Institute of Environmental, Chemical and Pharmaceutical Sciences, Federal University of São Paulo (UNIFESP), Diadema, SP, Brazil. Electronic address: lcaseli@unifesp.br.
authors.forename: Luciano
authors.initials: L
authors.lastname: Caseli
mesh_terms: D015060:1,2-Dipalmitoylphosphatidylcholine / Q000737:chemistry*; D000388:Air; D002462:Cell Membrane / Q000737:chemistry*; D057927:Hydrophobic and Hydrophilic Interactions; D053768:Metal Nanoparticles / Q000737:chemistry*; D012834:Silver / Q000737:chemistry*; D013499:Surface Properties; D014867:Water / Q000737:chemistry
chemical_list: D014867:Water; D015060:1,2-Dipalmitoylphosphatidylcholine; D012834:Silver
keywords: Air-water interface; Langmuir monolayers; Membrane models; PEBA; Silver nanoparticles