Modeling Alzheimer’s disease with brain organoids: mechanisms, applications, and future directions

Abstract

Human pluripotent stem cell-derived brain organoids have emerged as a transformative platform for modeling Alzheimer’s disease (AD), thus addressing long-standing translational obstacles posed by the disease’s complex etiology and interspecies differences. This review systematically examines methodological advances in brain organoid technology, from basic fabrication and brain-region-specific organoids to multicellular assembloids that incorporate microglia and vascular components, with an emphasis on strategies for overcoming fetal-like phenotypes. We surveyed literature published between 2018 and April 2026 that focused on human iPSC-derived organoid models that recapitulate core AD pathologies, including Aβ plaques, tau tangles, neuroinflammation, and blood–brain barrier dysfunction. Key findings demonstrate that organoids effectively capture genotype–phenotype relationships for major AD genes (APP, PSEN1, PSEN2, and APOEε4), enable the dissection of signaling pathway dysregulation (Wnt/β-catenin), and when combined with CRISPR editing and single-cell multi-omics, reveal cell-type-specific disease mechanisms. Organoids have also been successfully applied to patient-specific “avatar” models and high-throughput drug screening, thus advancing precision medicine approaches. However, current technological bottlenecks—including a lack of functional vascularization, batch-to-batch variability, and insufficient standardization—limit the full recapitulation of chronic, age-dependent AD pathology. This review critically evaluates these limitations, addresses ethical considerations surrounding neural organoids, and looks forward to future integration with artificial intelligence, spatial omics, and multi-organ systems to accelerate the translation of organoid-based discoveries into clinical applications.