Recent developments in the chemical biology of amyloid-ß oligomer targeting.

Aggregation of amyloid-ß (Aß) peptides is characteristic of Alzheimer's disease (AD), which is the most common neurodegenerative disorder. Increasing evidence shows that Aß oligomers, the intermediates during aggregation, rather than the fully mature fibrils are the most toxic species of Aß and the key contributors to neurodegeneration. Aß oligomers have been considered as both biomarkers and drug targets for the diagnosis and treatment of AD. However, the high heterogeneity and metastability of oligomers make it difficult to determine their exact pathogenic mechanisms. Recent developments in Aß oligomer-targeting agents and techniques have provided great opportunities for overcoming the existing limitations. This review introduces the formation, structure, and toxicity of Aß oligomers and categorizes the Aß oligomer-targeting agents based on their chemical biological applications, including recognition and detection of Aß oligomers for diagnosis, intervention of Aß oligomerization for treatment, and stabilization of Aß oligomers for pathogenic studies. The design strategies and working mechanisms of the representative examples published in the past five years are highlighted. Finally, future development directions and challenges of Aß oligomer targeting are tentatively proposed.