Antibodies and aptamers as affinity ligands for exosome isolation, detection, and targeted delivery: A review

Exosomes, key mediators of intercellular communication, are emerging as promising tools for disease diagnosis and therapy. Realizing this potential depends on technologies that can isolate, detect, and deliver exosomes with high specificity and efficiency. Affinity-based strategies that exploit the molecular recognition of antibodies and aptamers are central to this effort. In this review, we analyze how these ligands are advancing exosome research. We first examine isolation methods, benchmarking affinity capture against conventional techniques and weighing trade-offs among yield, purity, and vesicle integrity. We next explore detection technologies, in which antibody- and aptamer-based biosensors enable ultrasensitive, multiplexed, and point-of-care assays. Finally, we discuss the therapeutic frontier, where ligand-mediated surface functionalization creates targeted delivery vehicles. In preclinical models, engineered exosomes can traverse biological barriers and deliver multimodal payloads, indicating potential therapeutic avenues for cancer as well as neurodegenerative and metabolic disorders. Taken together, we highlight the synergy between affinity ligands and exosome science and outline key challenges for clinical translation.