The University of Southampton
University of Southampton Institutional Repository

Silica nanoparticles permeabilize lipid bilayers

Silica nanoparticles permeabilize lipid bilayers
Silica nanoparticles permeabilize lipid bilayers
Potential toxic effects of synthetic nanoparticles are of great public concern. Presently, the impact of nanoparticles at a cellular level is assessed by adding nanoparticles to cell cultures and subsequent evaluation of particle uptake by confocal fluorescence microscopy and of cell viability by conventional (fluorescence) assays. Cytotoxic effects of nanoparticles have been reported but a correlation between nanoparticle properties (e.g. size, shape, surface chemistry) and cell viability remains elusive. However, cellular uptake of nanoparticles is almost universally observed. Membrane translocation of nanoparticles is generally considered to be an active process, requiring the presence of receptors that mediate encapsulation of the nanoparticles into an intracellular vesicle, from which the particles may or may not escape into the cytosol. Using electrophysiological methods we have demonstrated that spherical silica nanoparticles, under development for intracellular drug delivery, are able to permeabilize protein-free lipid bilayers as a function of size and surface charge. Single channel-like conductances, similar to those induced by membrane-disrupting ?-amyloid peptides, are observed for rigid sterol-containing bilayers. For more fluid bilayers of DOPC the conductance gradually increases until the bilayer disintegrates, which has also been observed for cytotoxic amyloid oligomers. The most disruptive nanospheres were shown by confocal fluorescence microscopy to accumulate at the bilayer surface, and we demonstrated that a fraction of these particles translocate across the lipid bilayer, suggesting that passive uptake of nanoparticles may contribute to cellular uptake. Our combined electrophysiology and fluorescence microscopy approach is experimentally straightforward and enables rapid systematic investigation of the interactions between nanoparticles and the lipid components of the cell membrane. These model studies will aid in the rational design of safe nanoparticles -for drug delivery and subcellular labeling- that traverse the plasma membrane without adverse effects on membrane integrity.
401a-402a
Aghdaei, Sara
6bb71f1d-c8be-458c-a787-35336308282e
Morgan, Hywel
de00d59f-a5a2-48c4-a99a-1d5dd7854174
de Planque, Maurits R.R.
a1d33d13-f516-44fb-8d2c-c51d18bc21ba
Aghdaei, Sara
6bb71f1d-c8be-458c-a787-35336308282e
Morgan, Hywel
de00d59f-a5a2-48c4-a99a-1d5dd7854174
de Planque, Maurits R.R.
a1d33d13-f516-44fb-8d2c-c51d18bc21ba

Aghdaei, Sara, Morgan, Hywel and de Planque, Maurits R.R. (2010) Silica nanoparticles permeabilize lipid bilayers At 54th Annual Meeting of the Biophysical Society, United States. 20 - 24 Feb 2010. , 401a-402a.

Record type: Conference or Workshop Item (Poster)

Abstract

Potential toxic effects of synthetic nanoparticles are of great public concern. Presently, the impact of nanoparticles at a cellular level is assessed by adding nanoparticles to cell cultures and subsequent evaluation of particle uptake by confocal fluorescence microscopy and of cell viability by conventional (fluorescence) assays. Cytotoxic effects of nanoparticles have been reported but a correlation between nanoparticle properties (e.g. size, shape, surface chemistry) and cell viability remains elusive. However, cellular uptake of nanoparticles is almost universally observed. Membrane translocation of nanoparticles is generally considered to be an active process, requiring the presence of receptors that mediate encapsulation of the nanoparticles into an intracellular vesicle, from which the particles may or may not escape into the cytosol. Using electrophysiological methods we have demonstrated that spherical silica nanoparticles, under development for intracellular drug delivery, are able to permeabilize protein-free lipid bilayers as a function of size and surface charge. Single channel-like conductances, similar to those induced by membrane-disrupting ?-amyloid peptides, are observed for rigid sterol-containing bilayers. For more fluid bilayers of DOPC the conductance gradually increases until the bilayer disintegrates, which has also been observed for cytotoxic amyloid oligomers. The most disruptive nanospheres were shown by confocal fluorescence microscopy to accumulate at the bilayer surface, and we demonstrated that a fraction of these particles translocate across the lipid bilayer, suggesting that passive uptake of nanoparticles may contribute to cellular uptake. Our combined electrophysiology and fluorescence microscopy approach is experimentally straightforward and enables rapid systematic investigation of the interactions between nanoparticles and the lipid components of the cell membrane. These model studies will aid in the rational design of safe nanoparticles -for drug delivery and subcellular labeling- that traverse the plasma membrane without adverse effects on membrane integrity.

Full text not available from this repository.

More information

Accepted/In Press date: 22 February 2010
Additional Information: Event Dates: 20th - 24th February 2010
Venue - Dates: 54th Annual Meeting of the Biophysical Society, United States, 2010-02-20 - 2010-02-24
Organisations: Nanoelectronics and Nanotechnology

Identifiers

Local EPrints ID: 271842
URI: http://eprints.soton.ac.uk/id/eprint/271842
PURE UUID: a20b32ab-4645-44ae-985e-661e61595ae5
ORCID for Hywel Morgan: ORCID iD orcid.org/0000-0003-4850-5676
ORCID for Maurits R.R. de Planque: ORCID iD orcid.org/0000-0002-8787-0513

Catalogue record

Date deposited: 23 Dec 2010 18:19
Last modified: 18 Jul 2017 06:38

Export record

Contributors

Author: Sara Aghdaei
Author: Hywel Morgan ORCID iD

University divisions

Download statistics

Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.

View more statistics

Atom RSS 1.0 RSS 2.0

Contact ePrints Soton: eprints@soton.ac.uk

ePrints Soton supports OAI 2.0 with a base URL of http://eprints.soton.ac.uk/cgi/oai2

This repository has been built using EPrints software, developed at the University of Southampton, but available to everyone to use.

We use cookies to ensure that we give you the best experience on our website. If you continue without changing your settings, we will assume that you are happy to receive cookies on the University of Southampton website.

×