High antioxidant activity of gadolinium-yttrium orthovanadate nanoparticles in cell-free and biological milieu.

Oxidative stress caused by an overproduction of reactive oxygen species (ROS) is the key factor in developing a variety of pathological conditions. Recently various nanomaterials have attracted growing interest as nanoantioxidants with ROS-regulating ability. Here, for the first time, we report on high antioxidant behavior (enzyme-like activity) of GdYVO4:Eu3+nanoparticles (GdYVO NPs) revealed by spectroscopic methods both in cell-free and biological milieu using various ROS sensors. It was revealed that GdYVO NPs (d= 2 nm) effectively scavenge hydroxyl radicals·OH,superoxide anionsO2·-,hydrogen peroxideH2O2,peroxyl radicalsROO·,and remarkably reduce the lipopolysaccharide-induced ROS generation in rat leukocytes. The antioxidant activity of GdYVO NPs is ascribed to high amount of V4+and V3+ions in the structure of the NPs and the reversible switchingV3+↔V4+andV4+↔V5+vanadium oxidation states.