Recent Progress in Nanomedicine for the Diagnosis and Treatment of Alzheimer's Diseases.

Alzheimer's disease (AD) is a neurodegenerative disease that causes memory loss and progressive and permanent deterioration of cognitive function. The most challenging issue in combating AD is its complicated pathogenesis, which includes the deposition of amyloid β (Aβ) plaques, intracellular hyperphosphorylated tau protein, neurofibrillary tangles (NFT), etc. Despite rapid advancements in mechanistic research and drug development for AD, the currently developed drugs only improve cognitive ability and temporarily relieve symptoms but cannot prevent the development of AD. Moreover, the blood-brain barrier (BBB) creates a huge barrier to drug delivery in the brain. Therefore, effective diagnostic tools and treatments are urgently needed. In recent years, nanomedicine has provided opportunities to overcome the challenges and limitations associated with traditional diagnostics or treatments. Various types of nanoparticles (NPs) play an essential role in nanomedicine for the diagnosis and treatment of AD, acting as drug carriers to improve targeting and bioavailability across/bypass the BBB or acting as drugs directly on AD lesions. This review categorizes different types of NPs and summarizes their applications in nanomedicine for the diagnosis and treatment of AD. It also discusses the challenges associated with clinical applications and explores the latest developments and prospects of nanomedicine for AD.