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Adsorption of Nanoceria by Phosphocholine Liposomes

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Date

2016-12-13

Authors

Liu, Yibo
Liu, Juewen

Journal Title

Journal ISSN

Volume Title

Publisher

American Chemical Society

Abstract

Nanoceria (CeO2 nanoparticle) possesses a number of enzyme-like activities. In particular, it scavenges reactive oxygen species based on in-vitro and in vivo antioxidation studies. An important aspect of fundamental physical understanding is its interaction with lipid membranes that are the main components of the cell membrane. In this work, adsorption of nanoceria onto phosphocholine (PC) liposomes was performed. PC lipids are the main constituents of the cell outer membrane. Using a fluorescence quenching assay, a nanoceria adsorption isotherm was determined at various pH values and ionic strengths. A non-Langmuir isotherm occurred at pH 4 because of lateral electrostatic repulsion among the adsorbed cationic nanoceria. The phosphate group in the PC lipid is mainly responsible for the interaction, and the adsorbed nanoceria can be displaced by free inorganic phosphate. The tendency of the system to form large aggregates is a function of pH and the concentration of nanoceria, attributable to nanoceria being positively charged at pH 4 and neutral at physiological pH. Calcein leakage tests indicate that nanoceria induces liposome leakage because of transient lipid phase transition, and cryo-transmission electron microscopy indicates that the overall shape of the liposome is retained although deformation is still observed. This study provides fundamental biointerfacial information at a molecular level regarding the interaction of nanoceria and model cell membranes.

Description

This document is the Accepted Manuscript version of a Published Work that appeared in final form in Langmuir, © 2016 American Chemical Society after peer review and technical editing by publisher. To access the final edited and published work see Liu, Y., & Liu, J. (2016). Adsorption of Nanoceria by Phosphocholine Liposomes. Langmuir, 32(49), 13276–13283. https://doi.org/10.1021/acs.langmuir.6b03342

Keywords

Cerium Oxide Nanoparticles, Supported Lipid-Bilayers, Active Nanomaterials, Silica Nanoparticles, Oxidative Stress, Content Release, Mechanism, Delivery, DNA, Interface

LC Keywords

Citation

URI

http://dx.doi.org/10.1021/acs.langmuir.6b03342
 http://hdl.handle.net/10012/11807

Collections

Waterloo Research
Chemistry
Waterloo Institute for Nanotechnology