Cerium Oxide Nanoparticles with Entrapped Gadolinium for High T1 Relaxivity and ROS-Scavenging Purposes

• Published in: ACS omega Vol. 7; no. 24; pp. 21337 - 21345
• Main Authors: Eriksson, Peter, Truong, Anh H.T., Brommesson, Caroline, du Rietz, Anna, Kokil, Ganesh R., Boyd, Robert D., Hu, Zhangjun, Dang, Tram T., Persson, Per O. A., Uvdal, Kajsa
• Format: Journal Article
• Language: English
• Published: American Chemical Society 07-06-2022
• ISSN: 2470-1343
• DOI: 10.1021/acsomega.2c03055

Gadolinium chelates
are employed worldwide today as clinical contrast
agents for magnetic resonance imaging. Until now, the commonly used
linear contrast agents based on the rare-earth element gadolinium
have been considered safe and well-tolerated. Recently, concerns regarding
this type of contrast agent have been reported, which is why there
is an urgent need to develop the next generation of stable contrast
agents with enhanced spin–lattice relaxation, as measured by
improved
T
1
relaxivity at lower doses.
Here, we show that by the integration of gadolinium ions in cerium
oxide nanoparticles, a stable crystalline 5 nm sized nanoparticulate
system with a homogeneous gadolinium ion distribution is obtained.
These cerium oxide nanoparticles with entrapped gadolinium deliver
strong
T
1
relaxivity per gadolinium ion
(
T
1
relaxivity,
r
1
= 12.0 mM
–1
s
–1
) with
the potential to act as scavengers of reactive oxygen species (ROS).
The presence of Ce
3+
sites and oxygen vacancies at the
surface plays a critical role in providing the antioxidant properties.
The characterization of radial distribution of Ce
3+
and
Ce
4+
oxidation states indicated a higher concentration
of Ce
3+
at the nanoparticle surfaces. Additionally, we
investigated the ROS-scavenging capabilities of pure gadolinium-containing
cerium oxide nanoparticles by bioluminescent imaging in vivo, where
inhibitory effects on ROS activity are shown.