title: Demonstration of the interactions between aromatic compound-loaded lipid nanocapsules and Acinetobacter baumannii bacterial membrane.
abstract: Acinetobacter baumannii is an important nosocomial pathogen that is resistant to many commonly-used antibiotics. One strategy for treatment is the use of aromatic compounds (carvacrol, cinnamaldehyde) against A. baumannii. The aim of this study was to determine the interactions between bacteria and lipid nanocapsules (LNCs) over time based on the fluorescence of 3,3'-Dioctadecyloxacarbocyanine Perchlorate-LNCs (DiO-LNCs) and the properties of trypan blue to analyse the physicochemical mechanisms occurring at the level of the biological membrane. The results demonstrated the capacity of carvacrol-loaded LNCs to interact with and penetrate the bacterial membrane in comparison with cinnamaldehyde-loaded LNCs and unloaded LNCs. Modifications of carvacrol after substitution of hydroxyl functional groups by fatty acids demonstrated the crucial role of hydroxyl functions in antibacterial activity. Finally, after contact with the efflux pump inhibitor, carbonylcyanide-3-chlorophenyl hydrazine (CCCP), the results indicated the total synergistic antibacterial effect with Car-LNCs, showing that CCCP is associated with the action mechanism of carvacrol, especially at the level of the efflux pump mechanism.
authors.affiliation: LUNAM Université, F-49933 Angers, France; INSERM U1066, Micro et Nanomédecines Biomimétiques, IBS-CHU, 4 Rue Larrey, 49933 Angers, France. Electronic address: angelique.montagu@gmail.com.
authors.forename: A
authors.initials: A
authors.lastname: Montagu
authors.affiliation: ATOMycA, INSERM Atip-Avenir Team, CRCNA, INSERM U892, 6299 CNRS, University of Angers, 4 Rue Larrey, 49933 Angers, France. Electronic address: mljoly-guillou@chu-angers.fr.
authors.forename: M-L
authors.initials: ML
authors.lastname: Joly-Guillou
authors.affiliation: Service Commun de Cytometrie et d'analyse Nucleotidique (SCCAN), IFR 132, IBS - CHU, 4 Rue Larrey, 49933 Angers, France. Electronic address: catherine.guillet@univ-angers.fr.
authors.forename: C
authors.initials: C
authors.lastname: Guillet
authors.affiliation: LUNAM Université, F-49933 Angers, France; INSERM U1066, Micro et Nanomédecines Biomimétiques, IBS-CHU, 4 Rue Larrey, 49933 Angers, France. Electronic address: jerome.bejaud@univ-angers.fr.
authors.forename: J
authors.initials: J
authors.lastname: Bejaud
authors.affiliation: Eydopharma, 41 Rue Noel Ballay, 28000 Chartres, France. Electronic address: e.rossines@eydo.eu.
authors.forename: E
authors.initials: E
authors.lastname: Rossines
authors.affiliation: LUNAM Université, F-49933 Angers, France; INSERM U1066, Micro et Nanomédecines Biomimétiques, IBS-CHU, 4 Rue Larrey, 49933 Angers, France. Electronic address: patrick.saulnier@univ-angers.fr.
authors.forename: P
authors.initials: P
authors.lastname: Saulnier
mesh_terms: D000151:Acinetobacter Infections / Q000188:drug therapy; D040981:Acinetobacter baumannii / Q000187:drug effects*; D000171:Acrolein / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000494:pharmacology; D000900:Anti-Bacterial Agents / Q000008:administration & dosage / Q000494:pharmacology; D002232:Carbocyanines / Q000737:chemistry*; D002258:Carbonyl Cyanide m-Chlorophenyl Hydrazone / Q000378:metabolism; D000081007:Cymenes; D008055:Lipids / Q000737:chemistry; D039821:Monoterpenes / Q000008:administration & dosage* / Q000494:pharmacology; D053769:Nanocapsules
chemical_list: D000900:Anti-Bacterial Agents; D002232:Carbocyanines; D000081007:Cymenes; D008055:Lipids; D039821:Monoterpenes; D053769:Nanocapsules; D002258:Carbonyl Cyanide m-Chlorophenyl Hydrazone; C098044:3,3'-dioctadecyloxacarbocyanine; D000171:Acrolein; C073316:carvacrol; C012843:cinnamaldehyde
keywords: Aromatic compounds; DiO-lipid nanocapsules; Hydroxyl functions; Multi-drug resistant bacteria; Pump mechanism