http://dx.doi.org/10.1021/jz402234c

Giulia Rossi, Jonathan Barnoud, and Luca Monticelli
Polystyrene Nanoparticles Perturb Lipid Membranes
J. Phys. Chem. Lett., 2014, 5 (1), pp 241–246
DOI: 10.1021/jz402234c
Abstract: Polystyrene is abundant in marine debris. Like most synthetic
polymers, it degrades very slowly, producing smaller and smaller
particles easily ingested by wildlife. The presence of plastic
microscopic particles in fish and marine wildlife is massive and well
documented, but its impact on cellular activity is not understood.
Biological activity generally requires interaction with biological
membranes, but this is difficult to study at the molecular scale in
vivo. Here we use coarse-grained molecular simulations to determine the
effect of nanosized polystyrene (PS) particles on the properties of
model biological membranes. We find that PS nanoparticles permeate
easily into lipid membranes. Dissolved in the membrane core, PS chains
alter membrane structure, significantly reduce molecular diffusion, and
soften the membrane. Moreover, PS severely affects membrane lateral
organization by stabilizing raft-like domains. Changes in membrane
properties and lateral organization can severely affect the activity of
membrane proteins and thereby cellular function.
Keywords: lipid membranes; polymers; nanoparticle; coarse-grained
models; molecular dynamics; rafts