30 Aug Synthesis of stable cerium oxide nanoparticles coated with phosphonic acid-based functional polymers Back to Sci. Publications
AUTHORS
A. Dhouib, B. Mezghrani, G. Finocchiaro, R. Le Borgne, M. Berthet, B. Daydé-Cazals, A. Graillot, X. Ju, J.-F. Berret
JOURNAL
Langmuir, 39, 23, 8141–8152
ABSTRACT
Functional polymers, such as poly(ethylene glycol) (PEG), terminated with a single phosphonic acid, hereafter PEGik-Ph are often applied to coat metal oxide surfaces during post-synthesis steps but are not sufficient to stabilize sub-10 nm particles in protein-rich biofluids. The instability is attributed to the weak binding affinity of post-grafted phosphonic acid groups, resulting in a gradual detachment of the polymers from the surface. Here, we assess these polymers as coating agents using an alternative route, namely, the one-step wet-chemical synthesis, where PEGik-Ph is introduced with cerium precursors during the synthesis. Characterization of the coated cerium oxide nanoparticles (CNPs) indicates a core–shell structure, where the cores are 3 nm cerium oxide and the shell consists of functionalized PEG polymers in a brush configuration. Results show that CNPs coated with PEG1k-Ph and PEG2k-Ph are of potential interest for applications as nanomedicines due to their high Ce(III) content and increased colloidal stability in cell culture media. We further demonstrate that the CNPs in the presence of hydrogen peroxide show an additional absorbance band in the UV–vis spectrum, which is attributed to Ce–O22– peroxo-complexes and could be used in the evaluation of their catalytic activity for scavenging reactive oxygen species.
KEYWORDS
RELATED PROJECT: SRIC-ON
The ANR-sponsored project STRIC-ON aims to develop antioxidant nanoparticles of cerium oxide coated with innovative polymers and biomolecules to provide neuronal and vascular protection post-stroke. The project’s outcome will be to ascertain the potential of these innovative nanoparticles as therapeutic agents for stroke.
Within this initiative, SPECIFIC POLYMERS focused on synthesizing model macromolecules and biocompatible (co)polymers that combine anchoring groups, biocompatible polymeric chains, and additional functionalities to enable subsequent coupling reactions. Indeed, to achieve optimal efficiency, nanoparticles should be coated to enhance their biocompatibility, cellular uptake, circulation, or kidney clearance prevention. The coating could also be functionalized on their surface with specific moieties to facilitate the attachment of targeting molecules, such as peptides, antibodies, or oligoanilines. The synthesis of various multi-functional polymers for encapsulating nanoparticles and imparting the necessary set of properties was initiated during the ICONS project and will continue within STRIC-ON.
