title: Lipopolysaccharide Density and Structure Govern the Extent and Distance of Nanoparticle Interaction with Actual and Model Bacterial Outer Membranes.
abstract: Design of nanomedicines and nanoparticle-based antimicrobial and antifouling formulations and assessment of the potential implications of nanoparticle release into the environment requires understanding nanoparticle interaction with bacterial surfaces. Here we demonstrate the electrostatically driven association of functionalized nanoparticles with lipopolysaccharides of Gram-negative bacterial outer membranes and find that lipopolysaccharide structure influences the extent and location of binding relative to the outer leaflet-solution interface. By manipulating the lipopolysaccharide content in Shewanella oneidensis outer membranes, we observed the electrostatically driven interaction of cationic gold nanoparticles with the lipopolysaccharide-containing leaflet. We probed this interaction by quartz crystal microbalance with dissipation monitoring (QCM-D) and second harmonic generation (SHG) using solid-supported lipopolysaccharide-containing bilayers. The association of cationic nanoparticles increased with lipopolysaccharide content, while no association of anionic nanoparticles was observed. The harmonic-dependence of QCM-D measurements suggested that a population of the cationic nanoparticles was held at a distance from the outer leaflet-solution interface of bilayers containing smooth lipopolysaccharides (those bearing a long O-polysaccharide). Additionally, smooth lipopolysaccharides held the bulk of the associated cationic particles outside of the interfacial zone probed by SHG. Our results demonstrate that positively charged nanoparticles are more likely to interact with Gram-negative bacteria than are negatively charged particles, and this interaction occurs primarily through lipopolysaccharides.
authors.forename: Kurt H
authors.initials: KH
authors.lastname: Jacobson
authors.affiliation: Department of Chemistry, University of Minnesota , Minneapolis, Minnesota 55455, United States.
authors.forename: Ian L
authors.initials: IL
authors.lastname: Gunsolus
authors.forename: Thomas R
authors.initials: TR
authors.lastname: Kuech
authors.affiliation: Department of Chemistry, Northwestern University , Evanston, Illinois 60208, United States.
authors.forename: Julianne M
authors.initials: JM
authors.lastname: Troiano
authors.forename: Eric S
authors.initials: ES
authors.lastname: Melby
authors.affiliation: Department of Chemistry, University of Illinois at Urbana-Champaign , Urbana, Illinois 61801, United States.
authors.forename: Samuel E
authors.initials: SE
authors.lastname: Lohse
authors.affiliation: Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory , Richland, Washington 99352, United States.
authors.forename: Dehong
authors.initials: D
authors.lastname: Hu
authors.affiliation: Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory , Richland, Washington 99352, United States.
authors.forename: William B
authors.initials: WB
authors.lastname: Chrisler
authors.affiliation: Department of Chemistry, University of Illinois at Urbana-Champaign , Urbana, Illinois 61801, United States.
authors.forename: Catherine J
authors.initials: CJ
authors.lastname: Murphy
authors.affiliation: Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory , Richland, Washington 99352, United States.
authors.forename: Galya
authors.initials: G
authors.lastname: Orr
authors.affiliation: Department of Chemistry, Northwestern University , Evanston, Illinois 60208, United States.
authors.forename: Franz M
authors.initials: FM
authors.lastname: Geiger
authors.affiliation: Department of Chemistry, University of Minnesota , Minneapolis, Minnesota 55455, United States.
authors.forename: Christy L
authors.initials: CL
authors.lastname: Haynes
authors.forename: Joel A
authors.initials: JA
authors.lastname: Pedersen
mesh_terms: D000838:Anions; D001422:Bacterial Adhesion / Q000187:drug effects; D002412:Cations; D002462:Cell Membrane / Q000187:drug effects*; D006046:Gold / Q000737:chemistry; D057446:Hydrodynamics; D008051:Lipid Bilayers / Q000737:chemistry; D008070:Lipopolysaccharides / Q000737:chemistry*; D008567:Membranes, Artificial; D053768:Metal Nanoparticles / Q000633:toxicity*; D010743:Phospholipids / Q000737:chemistry; D058525:Quartz Crystal Microbalance Techniques; D020592:Shewanella / Q000166:cytology / Q000187:drug effects*; D012996:Solutions; D055672:Static Electricity; D013438:Sulfhydryl Compounds / Q000737:chemistry
chemical_list: C112396:2-mercapto-propylamine; D000838:Anions; D002412:Cations; D008051:Lipid Bilayers; D008070:Lipopolysaccharides; D008567:Membranes, Artificial; D010743:Phospholipids; D012996:Solutions; D013438:Sulfhydryl Compounds; D006046:Gold