title: Embedded silver ions-containing liposomes in polyelectrolyte multilayers: cargos films for antibacterial agents.
abstract: A new antibacterial coating made of poly(L-lysine)/hyaluronic acid (PLL/HA) multilayer films and liposome aggregates loaded with silver ions was designed. Liposomes filled with an AgNO 3 solution were first aggregated by the addition of PLL in solution. The obtained micrometer-sized aggregates were then deposited on a PLL/HA multilayer film, playing the role of a spacer with the support. Finally, HA/PLL/HA capping layers were deposited on top of the architecture to form a composite AgNO 3 coating. Release of encapsulated AgNO 3 from this composite coating was followed and triggered upon temperature increase over the transition temperature of vesicles, found to be equal to 34 degrees C. After determination of the minimal inhibitory concentration (MIC) of AgNO 3 in solution, the antibacterial activity of the AgNO 3 coating was investigated against Escherichia coli. A 4-log reduction in the number of viable E. coli cells was observed after contact for 120 min with a 120 ng/cm (2) AgNO 3 coating. In comparison, no bactericidal activity was found for PLL/HA films previously dipped in an AgNO 3 solution and for PLL/HA films with liposome aggregates containing no AgNO 3 solution. The strong bactericidal effect could be linked to the diffusion of silver ions out of the AgNO 3 coating, leading to an important bactericidal concentration close to the membrane of the bacteria. A simple method to prepare antibacterial coatings loaded with a high and controlled amount of AgNO 3 is therefore proposed. This procedure is far superior to that soaking AgNO 3 or Ag nanoparticles into a coating. In principle, other small bactericidal chemicals like antibiotics could be encapsulated by this method. This study opens a new route to modify surfaces with small solutes that are not permeating phospholipid membranes below the phase transition temperature.
authors.affiliation: Département de Chimie Bioorganique, Institut Gilbert Laustriat, UMR 7175 CNRS/Université Louis Pasteur, Illkirch, France.
authors.forename: Marta
authors.initials: M
authors.lastname: Malcher
authors.forename: Dmitry
authors.initials: D
authors.lastname: Volodkin
authors.forename: Béatrice
authors.initials: B
authors.lastname: Heurtault
authors.forename: Philippe
authors.initials: P
authors.lastname: André
authors.forename: Pierre
authors.initials: P
authors.lastname: Schaaf
authors.forename: Helmuth
authors.initials: H
authors.lastname: Möhwald
authors.forename: Jean-Claude
authors.initials: JC
authors.lastname: Voegel
authors.forename: Adam
authors.initials: A
authors.lastname: Sokolowski
authors.forename: Vincent
authors.initials: V
authors.lastname: Ball
authors.forename: Fouzia
authors.initials: F
authors.lastname: Boulmedais
authors.forename: Benoit
authors.initials: B
authors.lastname: Frisch
mesh_terms: D015060:1,2-Dipalmitoylphosphatidylcholine / Q000737:chemistry; D000900:Anti-Bacterial Agents / Q000737:chemistry; D000890:Anti-Infective Agents / Q000737:chemistry*; D004058:Diffusion; D004134:Dimyristoylphosphatidylcholine / Q000737:chemistry; D004926:Escherichia coli / Q000378:metabolism; D007477:Ions; D007700:Kinetics; D008081:Liposomes / Q000737:chemistry; D011107:Polylysine / Q000737:chemistry; D012834:Silver / Q000737:chemistry*; D012835:Silver Nitrate / Q000737:chemistry*; D013499:Surface Properties; D013696:Temperature
chemical_list: D000900:Anti-Bacterial Agents; D000890:Anti-Infective Agents; D007477:Ions; D008081:Liposomes; D011107:Polylysine; D015060:1,2-Dipalmitoylphosphatidylcholine; D012834:Silver; D012835:Silver Nitrate; D004134:Dimyristoylphosphatidylcholine