Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2013 May 6;14(5):9722-36.
doi: 10.3390/ijms14059722.

Molecular interaction of a new antibacterial polymer with a supported lipid bilayer measured by an in situ label-free optical technique

Robert Horvath  1 , Balázs Kobzi, Helmut Keul, Martin Moeller, Eva Kiss
Affiliations

Molecular interaction of a new antibacterial polymer with a supported lipid bilayer measured by an in situ label-free optical technique

Robert Horvath et al. Int J Mol Sci. .

Abstract

The interaction of the antibacterial polymer-branched poly(ethylene imine) substituted with quaternary ammonium groups, PEO and alkyl chains, PEI25QI5J5A815-with a solid supported lipid bilayer was investigated using surface sensitive optical waveguide spectroscopy. The analysis of the optogeometrical parameters was extended developing a new composite layer model in which the structural and optical anisotropy of the molecular layers was taken into consideration. Following in situ the change of optical birefringence we were able to determine the composition of the lipid/polymer surface layer as well as the displacement of lipid bilayer by the antibacterial polymer without using additional labeling. Comparative assessment of the data of layer thickness and optical anisotropy helps to reveal the molecular mechanism of antibacterial effect of the polymer investigated.

PubMed Disclaimer

Figures

Figure 1
Figure 1
Optical thickness (Q) as a function of time (t) on the waveguide surface in the course of lipid vesicle/antimicrobial polymer deposition.
Figure 2
Figure 2
Refractive index (ñA) and layer thickness (d̃A) during lipid vesicle/antimicrobial polymer insertion as a function of time (t) using the homogeneous and isotropic layer model (arrows indicate the axis of plotted data).
Figure 3
Figure 3
Birefringence (ne − no) and layer thickness, dA obtained during lipid bilayer formation (a) and adsorption of the antibacterial polymer; (b) using the anisotropic optical adlayer model (arrows indicate the axis of plotted data). The refractive index ellipsoids and the structure of the films are also shown.
Figure 3
Figure 3
Birefringence (ne − no) and layer thickness, dA obtained during lipid bilayer formation (a) and adsorption of the antibacterial polymer; (b) using the anisotropic optical adlayer model (arrows indicate the axis of plotted data). The refractive index ellipsoids and the structure of the films are also shown.
Figure 4
Figure 4
Birefringence (ne − no) and layer thickness, dA during lipid vesicle/antibacterial polymer insertion as a function of time (t) using the anisotropic optical layer model (arrows indicate the axis of plotted data).
Figure 5
Figure 5
Surface coverages of lipid and polymer on the waveguide calculated from the composite model.
Figure 6
Figure 6
Scheme of the interaction of antibacterial polymer with supported lipid bilayer based on structural information obtained from OWLS measurement using the anisotropic model for data evaluation. The antibacterial polymer is adsorbed on top of the lipid bilayer with penetrating alkyl chains (a); antibacterial polymer-lipid complex is leaving the surface (b); lipid bilayer is disintegrated and exchanged by the polymer (c).
See this image and copyright information in PMC

References

    1. Ambroggio E.E., Bagatolli L.A., Goormaghtigh E., Fominaya J., Gasset M. Piercing Lipid Bilayers with Peptides. In: Leitmannova Liu A., editor. Advances in Planar Lipid Bilayers and Liposomes. Vol. 5. Elsevier; Amsterdam, The Netherlands: 2007. pp. 1–23.
    1. Munoz-Bonilla A., Fernandez-Garcia M. Polymeric materials with antimicrobial activity. Progr. Polym. Sci. 2012;37:281–339.
    1. Papareddy P., Mörgelin M., Walse B., Schmidtchen A., Malmsten M.J. Antimicrobial activity of peptides derived from human β-amyloid precursor protein. Pept. Sci. 2012;18:183–191. - PubMed
    1. Pelegrini P.B., Perseghini del Sarto R., Silva O.N., Franco O.L. Grossi-de-Sa1, M.F. Antibacterial peptides from plants: What they are and how they probably work. Biochem. Res. 2011 doi: 10.1155/2011/250349. - DOI - PMC - PubMed
    1. Rossetti F.F., Reviakine I., Csucs G., Assi F., Voros J., Textor M. Interaction of poly(l-lysine)-g-poly(ethylene glycol) with supported phospholipid bilayers. Biophys. J. 2004;87:1711–1721. - PMC - PubMed

Publication types