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Composition effects...
Composition effects on photooxidative membrane destabilization by TiO2 nanoparticles
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- Malekkhaiat Häffner, S. (author)
- University of Copenhagen
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- Parra-Ortiz, E. (author)
- University of Copenhagen
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- Skoda, M. W.A. (author)
- Rutherford Appleton Laboratory
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- Saerbeck, T. (author)
- Institut Laue Langevin
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- Browning, Kathryn Louise (author)
- University of Copenhagen
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- Malmsten, M. (author)
- Lund University,Lunds universitet,Fysikalisk kemi,Enheten för fysikalisk och teoretisk kemi,Kemiska institutionen,Institutioner vid LTH,Lunds Tekniska Högskola,Physical Chemistry,Physical and theoretical chemistry,Department of Chemistry,Departments at LTH,Faculty of Engineering, LTH,University of Copenhagen
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(creator_code:org_t)
- Elsevier BV, 2021
- 2021
- English 15 s.
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In: Journal of Colloid and Interface Science. - : Elsevier BV. - 0021-9797. ; 584, s. 19-33
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http://dx.doi.org/10...
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Abstract
Subject headings
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- 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.
Subject headings
- NATURVETENSKAP -- Kemi -- Fysikalisk kemi (hsv//swe)
- NATURAL SCIENCES -- Chemical Sciences -- Physical Chemistry (hsv//eng)
Keyword
- Neutrons
- Oxidation
- Phospholipids
- Supported lipid bilayers
- Titanium dioxide nanoparticles
Publication and Content Type
- art (subject category)
- ref (subject category)
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