Skip to main content

Lund University Publications

LUND UNIVERSITY LIBRARIES

Composition effects on photooxidative membrane destabilization by TiO2 nanoparticles

Malekkhaiat Häffner, S. ; Parra-Ortiz, E. ; Skoda, M. W.A. ; Saerbeck, T. ; Browning, Kathryn Louise and Malmsten, M. LU (2021) In Journal of Colloid and Interface Science 584. p.19-33
Abstract

Membrane interactions and photooxidative membrane destabilization of titanium dioxide (TiO2) nanoparticles were investigated, focusing on the effects of membrane composition, notably phospholipid headgroup charge and presence of cholesterol. For this, we employed a battery of state-of-the-art methods for studies of bilayers formed by zwitterionic palmitoyloleoylphosphatidylcholine (POPC) containing also polyunsaturated palmitoylarachidonoylphosphocholine (PAPC), as well as its mixtures with anionic palmitoyloleoylphosphatidylglycerol (POPG) and cholesterol. It was found that the TiO2 nanoparticles display close to zero charge at pH 7.4, resulting in aggregation. At pH 3.4, in contrast, the 6 nm TiO2... (More)

Membrane interactions and photooxidative membrane destabilization of titanium dioxide (TiO2) nanoparticles were investigated, focusing on the effects of membrane composition, notably phospholipid headgroup charge and presence of cholesterol. For this, we employed a battery of state-of-the-art methods for studies of bilayers formed by zwitterionic palmitoyloleoylphosphatidylcholine (POPC) containing also polyunsaturated palmitoylarachidonoylphosphocholine (PAPC), as well as its mixtures with anionic palmitoyloleoylphosphatidylglycerol (POPG) and cholesterol. It was found that the TiO2 nanoparticles display close to zero charge at pH 7.4, resulting in aggregation. At pH 3.4, in contrast, the 6 nm TiO2 nanoparticles are well dispersed due to a strongly positive ζ-potential. Mirroring this pH dependence, TiO2 nanoparticles were observed to bind to negatively charged lipid bilayers at pH 3.4, but much less so at pH 7.4. While nanoparticle binding has some destabilizing effect alone, illumination with ultraviolet (UV) light accentuates membrane destabilization, a result of oxidative stress caused by generated reactive oxygen species (ROS). Neutron reflectivity (NR), quartz crystal microbalance (QCM), and small-angle X-ray scattering (SAXS) results all demonstrate that membrane composition strongly influences membrane interactions and photooxidative destabilization of lipid bilayers. In particular, the presence of anionic POPG makes the bilayers more sensitive to oxidative destabilization, whereas a stabilizing effect was observed in the presence of cholesterol. Also, structural aspects of peroxidation were found to depend strongly on membrane composition, notably the presence of anionic phospholipids. The results show that membrane interactions and UV-induced ROS generation act in concert and need to be considered together to understand effects of lipid membrane composition on UV-triggered oxidative destabilization by TiO2 nanoparticles, e.g., in the context of oxidative damage of bacteria and cells.

(Less)
Please use this url to cite or link to this publication:
author
; ; ; ; and
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Neutrons, Oxidation, Phospholipids, Supported lipid bilayers, Titanium dioxide nanoparticles
in
Journal of Colloid and Interface Science
volume
584
pages
15 pages
publisher
Elsevier
external identifiers
  • pmid:33039680
  • scopus:85092223576
ISSN
0021-9797
DOI
10.1016/j.jcis.2020.09.046
language
English
LU publication?
yes
id
4a7df98c-797a-4118-83cd-4eab3b19a95b
date added to LUP
2020-10-26 09:06:52
date last changed
2024-03-20 17:09:33
@article{4a7df98c-797a-4118-83cd-4eab3b19a95b,
  abstract     = {{<p>Membrane interactions and photooxidative membrane destabilization of titanium dioxide (TiO<sub>2</sub>) nanoparticles were investigated, focusing on the effects of membrane composition, notably phospholipid headgroup charge and presence of cholesterol. For this, we employed a battery of state-of-the-art methods for studies of bilayers formed by zwitterionic palmitoyloleoylphosphatidylcholine (POPC) containing also polyunsaturated palmitoylarachidonoylphosphocholine (PAPC), as well as its mixtures with anionic palmitoyloleoylphosphatidylglycerol (POPG) and cholesterol. It was found that the TiO<sub>2</sub> nanoparticles display close to zero charge at pH 7.4, resulting in aggregation. At pH 3.4, in contrast, the 6 nm TiO<sub>2</sub> nanoparticles are well dispersed due to a strongly positive ζ-potential. Mirroring this pH dependence, TiO<sub>2</sub> nanoparticles were observed to bind to negatively charged lipid bilayers at pH 3.4, but much less so at pH 7.4. While nanoparticle binding has some destabilizing effect alone, illumination with ultraviolet (UV) light accentuates membrane destabilization, a result of oxidative stress caused by generated reactive oxygen species (ROS). Neutron reflectivity (NR), quartz crystal microbalance (QCM), and small-angle X-ray scattering (SAXS) results all demonstrate that membrane composition strongly influences membrane interactions and photooxidative destabilization of lipid bilayers. In particular, the presence of anionic POPG makes the bilayers more sensitive to oxidative destabilization, whereas a stabilizing effect was observed in the presence of cholesterol. Also, structural aspects of peroxidation were found to depend strongly on membrane composition, notably the presence of anionic phospholipids. The results show that membrane interactions and UV-induced ROS generation act in concert and need to be considered together to understand effects of lipid membrane composition on UV-triggered oxidative destabilization by TiO<sub>2</sub> nanoparticles, e.g., in the context of oxidative damage of bacteria and cells.</p>}},
  author       = {{Malekkhaiat Häffner, S. and Parra-Ortiz, E. and Skoda, M. W.A. and Saerbeck, T. and Browning, Kathryn Louise and Malmsten, M.}},
  issn         = {{0021-9797}},
  keywords     = {{Neutrons; Oxidation; Phospholipids; Supported lipid bilayers; Titanium dioxide nanoparticles}},
  language     = {{eng}},
  month        = {{02}},
  pages        = {{19--33}},
  publisher    = {{Elsevier}},
  series       = {{Journal of Colloid and Interface Science}},
  title        = {{Composition effects on photooxidative membrane destabilization by TiO<sub>2</sub> nanoparticles}},
  url          = {{http://dx.doi.org/10.1016/j.jcis.2020.09.046}},
  doi          = {{10.1016/j.jcis.2020.09.046}},
  volume       = {{584}},
  year         = {{2021}},
}