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.

Evaluation of cytotoxicity, immune compatibility and antibacterial activity of biogenic silver nanoparticles

“…Silver nanoparticles can be responsible for release of lipopolysaccharides and membrane proteins, collapsing of bacterial membrane potential induced by drop of ATP level by nano-Ag [52, 53]. Researches propose many mechanisms of AgNPs antibacterial activity, but still exact mechanism has not been confirmed and needs further studies.…”

Textiles Funcionales Como Barrera De Protección Ante Infecciones Asociadas a La Atención en Salud

“…Los mecanismos relacionados con la actividad antibacteriana de NP-Au comienzan con las fuerzas electrostáticas presentes tanto en la NP como en la bacteria, las cuales permiten la atracción y posterior unión a la pared celular que modifica el potencial de membrana, disminuye los niveles de ATP e induce a la muerte celular (Jacobson et al, 2015) (Cui et al, 2012.…”

Probing the Interaction between Nanoparticles and Lipid Membranes by Quartz Crystal Microbalance with Dissipation Monitoring

“…More realistic SLBs incorporating sterols such as cholesterols (Melby et al, 2016) and lipopolysaccharides (Jacobson et al, 2015) have been successfully formed and characterized using QCM-D. A recent study also reports the formation of phase segregated lipid rafts on a silica coated QCM-D crystal (Melby et al, 2016; Figure 1C). …”

“…Incorporation of lipopolysaccharides (LPS) and phase segregated lipid rafts are among these complex structures. Jacobson et al (2015) investigated the effect of LPS content on the interaction of anionic and cationic gold NPs with POPC SLBs. The outer membrane of Gram negative bacteria contains LPS; hence, incorporating it with POPC will increase the resemblance of the model membrane to that of Gram-negative bacteria.…”