  Oxidative stress, which is one of the main harmful mechanisms of pathologies
including is-chemic stroke, contributes to both neurons and endothelial cell
damages, leading to vascular lesions. Although many antioxidants have been
tested in preclinical studies, no treatment is currently available for stroke
patients. Since cerium oxide nanoparticles (CNPs) exhibit remarkable
antioxidant capacities, our objective is to develop an innovative coating to
enhance CNPs biocompatibility without disrupting their antioxidant capacities
or enhance their toxicity. This study reports the synthesis and
characterization of functional polymers and their impact on the enzyme-like
catalytic activity of CNPs. To study the toxicity and the antioxidant
properties of CNPs for stroke and particularly endothelial damages, in vitro
studies are conducted on a cerebral endothelial cell line (bEnd.3). Despite
their internalization in bEnd.3 cells, coated CNPs are devoid of cytotoxicity.
Microscopy studies report an intracellular localization of CNPs, more precisely
in endosomes. All CNPs reduces glutamate-induced intracellular production of
ROS in endothelial cells but one CNP significantly reduces both the production
of mitochondrial super-oxide anion and DNA oxidation. In vivo studies report a
lack of toxicity in mice. This study there-fore describes and identifies
biocompatible CNPs with interesting antioxidant properties for ischemic stroke
and related pathologies.
