Aging in 3D: Organoid Systems as Models to Uncover Cellular Senescence and Therapeutic Targets Across Diseases

Aging is a complex biological process characterized by progressive loss of cellular homeostasis, impaired regenerative capacity, and accumulation of senescent cells that collectively predispose tissues to disease. Traditional two-dimensional culture systems and animal models have provided valuable insights but fail to fully recapitulate the spatial organization, cellular heterogeneity, and microenvironmental cues of aging human tissues. Organoid technology—three-dimensional self-organizing structures derived from adult stem cells or pluripotent stem cells has emerged as a transformative platform to model aging in vitro. These mini-tissues retain the architecture, signaling dynamics, and lineage hierarchy of native organs, making them powerful systems to interrogate age-associated cellular phenotypes, DNA damage responses, and senescence programs. This review discusses how organoid models are advancing our understanding of aging biology across multiple organ systems, from the intestines and liver to the brain and lung. We highlighted key molecular pathways driving cellular senescence within organoids—including p16INK4a/p21CIP1 signaling, SASP activation, mitochondrial dysfunction, and epigenetic drift—and how these can be targeted to restore tissue homeostasis. We further discussed how organoids derived from aged tissues, induced pluripotent stem cells, and engineered oncogene systems reveal new therapeutic opportunities to modulate senescence in age-related disorders, cancer, and regenerative medicine. Finally, we discussed emerging integrative tools such as organoid co-cultures, single-cell omics, and senolytics drug screening that are expanding the potential of organoids as translational platforms for anti-aging and disease intervention.