Advances in Antioxidant Nanomedicines for Imaging and Therapy of Alzheimer's Disease.

Reactive oxygen species (ROS) are crucial signaling molecules in the regulation of numerous physiological activities including the formation and function of the central nervous system (CNS). So far, many functional antioxidant nanomedicines with ROS scavenging capability to reduce oxidative stress in Alzheimer's disease (AD) have been developed for both imaging and therapy of AD. This review focuses on the most recent advances in antioxidant nanomedicines such as ROS-scavenging nanoparticles (NPs), NPs with intrinsic antioxidant activity, and drug-loaded antioxidant NPs for AD theranostics. In addition to antioxidant nanomedicines, the emerging phototherapy treatment paradigms and the promising preclinic drug carriers, such as exosomes and liposomes, are also introduced. In general, excessive generation of ROS can cause lipid peroxidation, oxidative DNA, as well as protein damage, aggravating pathogenic alterations, accumulation of amyloid-beta plaques and neurofibrillary tangles in the brain. These negative factors further cause cell death, which is the beginning of AD. We anticipate that this review will help researchers in the area of preclinical research and clinical translation of antioxidant nanomedicines for AD imaging and therapy.