The Preparation Temperature Influences the Physicochemical Nature and Activity of Nanoceria

Authors

Robert A. Yokel, University of KentuckyFollow
Wendel Wohlleben, BASF, GermanyFollow
Johannes Georg Keller, BASF, GermanyFollow
Matthew L. Hancock, University of KentuckyFollow
Jason M. Unrine, University of KentuckyFollow
D. Allan Butterfield, University of KentuckyFollow
Eric A. Grulke, University of KentuckyFollow

Abstract

Cerium oxide nanoparticles, so-called nanoceria, are engineered nanomaterials prepared by many methods that result in products with varying physicochemical properties and applications. Those used industrially are often calcined, an example is NM-212. Other nanoceria have beneficial pharmaceutical properties and are often prepared by solvothermal synthesis. Solvothermally synthesized nanoceria dissolve in acidic environments, accelerated by carboxylic acids. NM-212 dissolution has been reported to be minimal. To gain insight into the role of high-temperature exposure on nanoceria dissolution, product susceptibility to carboxylic acid-accelerated dissolution, and its effect on biological and catalytic properties of nanoceria, the dissolution of NM-212, a solvothermally synthesized nanoceria material, and a calcined form of the solvothermally synthesized nanoceria material (ca. 40, 4, and 40 nm diameter, respectively) was investigated. Two dissolution methods were employed. Dissolution of NM-212 and the calcined nanoceria was much slower than that of the non-calcined form. The decreased solubility was attributed to an increased amount of surface Ce⁴⁺ species induced by the high temperature. Carboxylic acids doubled the very low dissolution rate of NM-212. Nanoceria dissolution releases Ce³⁺ ions, which, with phosphate, form insoluble cerium phosphate in vivo. The addition of immobilized phosphates did not accelerate nanoceria dissolution, suggesting that the Ce³⁺ ion release during nanoceria dissolution was phosphate-independent. Smaller particles resulting from partial nanoceria dissolution led to less cellular protein carbonyl formation, attributed to an increased amount of surface Ce³⁺ species. Surface reactivity was greater for the solvothermally synthesized nanoceria, which had more Ce³⁺ species at the surface. The results show that temperature treatment of nanoceria can produce significant differences in solubility and surface cerium valence, which affect the biological and catalytic properties of nanoceria.

Document Type

Article

Publication Date

6-4-2021

Notes/Citation Information

Published in Beilstein: Journal of Nanotechnology, v. 12.

© 2021 Yokel et al.; licensee Beilstein-Institut.

This is an Open Access article under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0). Please note that the reuse, redistribution and reproduction in particular requires that the author(s) and source are credited and that individual graphics may be subject to special legal provisions.

The license is subject to the Beilstein Journal of Nanotechnology terms and conditions: (https://www.beilstein-journals.org/bjnano/terms).

Digital Object Identifier (DOI)

https://doi.org/10.3762/bjnano.12.43

Funding Information

The research leading to these results received funding from the National Institutes of Health [grant agreement No R01GM109195] and the PATROLS project, as part of European Union’s Horizon 2020 research and innovation program [grant agreement No 760813].

Repository Citation

Yokel, Robert A.; Wohlleben, Wendel; Keller, Johannes Georg; Hancock, Matthew L.; Unrine, Jason M.; Butterfield, D. Allan; and Grulke, Eric A., "The Preparation Temperature Influences the Physicochemical Nature and Activity of Nanoceria" (2021). Pharmaceutical Sciences Faculty Publications. 164.
https://uknowledge.uky.edu/ps_facpub/164