Untangling the Interactions between Anionic Polystyrene Nanoparticles and Lipid Membranes Using Laurdan Fluorescence
Laura A Kesner1, Zeke A Piskulich2, Qiang Cui2
1Department of Chemistry and Biochemistry, University of Maryland Baltimore County, Baltimore, Maryland 21250, United States.
Journal of the American Chemical Society
|April 3, 2023
Summary
Anionic polystyrene nanoparticles significantly rearrange model cell membranes by penetrating lipid bilayers. This interaction creates a hybrid gel, altering membrane structure and function.
Area of Science:
- Nanotechnology
- Biophysics
- Materials Science
Background:
- Synthetic nanoparticles (NPs) can alter cell membrane function through induced rearrangements.
- Liposomes serve as valuable model systems for studying polymer-membrane interactions.
Purpose of the Study:
- To investigate the interactions between polystyrene nanoparticles (NPs) and liposomes.
- To elucidate the mechanisms by which NPs induce membrane rearrangements.
Main Methods:
- Laurdan fluorescence spectroscopy to quantify membrane lipid packing.
- Coarse-grained molecular dynamics (MD) simulations to visualize NP-membrane interactions.
Main Results:
- Anionic, non-cross-linked polystyrene NPs induced significant liposome membrane rearrangement compared to other NPs.
- MD simulations showed polymer chains penetrating the liposome membrane, forming a hybrid gel with lipids.
- Lipid packing decreased in both leaflets, indicating local membrane rearrangement.
Conclusions:
- Significant NP-induced membrane rearrangement requires a negative surface charge, a hydrophobic core, and the ability of non-cross-linked polymer chains to penetrate the membrane.
- The formation of a polystyrene-lipid hybrid gel is key to the observed membrane alterations.
