Dietary Fe3O4 Nanozymes Prevent the Injury of Neurons and Blood-Brain Barrier Integrity from Cerebral Ischemic Stroke.

Cerebral ischemic stroke stimulates excessive reactive oxygen species, which lead to blood-brain-barrier disruption, neuron death, and aggravated cerebral infarction. Thus, it is critical to develop an antioxidant strategy for stroke treatment. Herein, we report a dietary strategy to promote stroke healing using iron oxide (Fe3O4) nanoparticles with intrinsic enzyme-like activities. We find that Fe3O4 nanozymes exhibit triple enzyme-like activities, peroxidase, catalase, and superoxide dismutase, thus potentially possessing the ability to regulate the ROS level. Importantly, intragastric administration of PEG-modified Fe3O4 nanozymes significantly reduces cerebral infarction and neuronal death in a rodent model following cerebral ischemic stroke. Ex vivo analysis shows that PEG-modified Fe3O4 nanozymes localize in the cerebral vasculature, ameliorate local redox state with decreased malondialdehyde and increased Cu/Zn SOD, and facilitate blood-brain-barrier recovery by elevating ZO-1 and Claudin-5 in the hippocampus. Altogether, our results suggest that dietary PEG-modified Fe3O4 nanozymes can facilitate blood-brain-barrier reconstruction and protect neurons following ischemic stroke.