**Background:** The International Society for Extracellular Vesicles (ISEV) is the premier professional organization for EV research, with nearly 2000 members globally. The ISEV2023 annual meeting, held with over 1,000 anticipated attendees, covers the latest research on exosomes, microvesicles, and other extracellular vesicles. EVs are lipid membrane-bound nanoscale particles secreted by cells that carry proteins, nucleic acids, and lipids, mediating intercellular communication in both normal physiology and pathology. The field is rapidly advancing toward clinical applications, including diagnostics and therapeutics.
**Methods:** The abstract book contains hundreds of studies employing diverse methodologies. EV isolation methods include ultracentrifugation, size exclusion chromatography (SEC), tangential flow filtration (TFF), density gradient centrifugation, and precipitation. Characterization techniques include nanoparticle tracking analysis (NTA), transmission electron microscopy (TEM), cryo-TEM, atomic force microscopy (AFM), dynamic light scattering (DLS), western blotting, flow cytometry (including imaging flow cytometry and nano-flow cytometry), mass spectrometry, and single-vesicle analysis methods such as dSTORM and TIRF microscopy. Functional studies utilize in vitro assays (cell proliferation, migration, invasion, angiogenesis) and in vivo models (mouse models of cancer, myocardial infarction, lung injury, kidney disease, stroke, and neurodegenerative diseases).
**Key Results:** Featured abstracts highlight several major advances. FA01 shows that only 30% of vesicles are DNA-positive, with EV-DNA uniquely chromatinized, and that tumor-derived EV-DNA activates anti-tumor immunity in Kupffer cells to prevent metastatic progression in colorectal cancer. FA02 presents a method for single EV sizing and phenotyping using TIRF microscopy with viscous-enhanced medium. FA03 demonstrates that engineering EVs to present the Notch ligand Jagged1 (JAG1-Fc) at approximately 6 molecules per EV can treat LPS-induced lung injury in mice, while liposomes cannot. OT01 reports a global inter-laboratory comparison study showing that flow cytometer calibration reduces the coefficient of variation for platelet EV concentration from 72% to 40%. In cancer biomarkers (OT02), sEV-GCC2 shows an AUC of 0.856 for lung adenocarcinoma diagnosis, and a 26-protein panel identifies 96.5% of breast cancer patients. In therapeutics (OT04), iPSC-derived EVs tracked by MRI/MPI show detectability of approximately 4 × 10^7 EVs in mouse hearts post-myocardial infarction. In single EV analysis (OT05), multiplexed analysis (MASEV) using bioorthogonal click chemistry enables 12-plex biomarker profiling, revealing that 39% of EVs have no tetraspanins. In cancer immunology (OT06), extravesicular CD147 is identified as a mediator of tumor progression, and pancreatic tumors with impaired EV secretion show a pro-tumorigenic immune response sensitive to immunotherapy. In upscaling (OT07), MSC culture at low glucose concentration increases EV yield by 1.4-fold, and Raman spectroscopy enables continuous glucose monitoring (R² = 0.923). In kidney disease (OT08), spatial transcriptomics reveals that AFSC-EVs restore glomerular homeostasis pathways in Alport syndrome. In cancer pathogenesis (OF09), sEV-associated ITGB2 from the lung pro-thrombotic niche drives cancer-associated thromboembolism and metastasis. In tissue injury and repair (OF10), wound macrophage-derived exosomes carrying TOMM70 enable keratinocyte migration for functional wound closure. In bacteria studies (OF11), probiotic-derived outer membrane vesicles reduce allergic airway inflammation in a TLR4-dependent manner. In fundamental biology (OF12), the ATPase activity of the phosphatidylethanolamine flippase TAT-5 inhibits EV budding, and cellular cholesterol levels regulate EV RNA contents via ORP1L. In metastasis (OF13), brain-seeking breast cancer EVs alter BBB endothelial cell metabolism, and angiocrine EVs impose a mesenchymal phenotype on proneural glioma stem cells. In neurodegenerative diseases (OF14), exophers (novel large EVs) in mammalian neurons are highly responsive to tauopathy, and ATP1A3 is identified as a novel marker for isolating neuron-specific EVs from biofluids.
**Clinical Implications:** The research presented at ISEV2023 demonstrates that EVs are rapidly moving toward clinical translation. Key applications include: (1) liquid biopsy biomarkers for early cancer detection (breast cancer, lung adenocarcinoma, colorectal cancer, ovarian cancer, prostate cancer); (2) therapeutic agents for tissue repair (myocardial infarction, lung injury, kidney disease, tendon healing, wound healing, stroke); (3) drug delivery vehicles for RNA therapeutics, CRISPR/Cas9 systems, and chemotherapeutic agents; (4) engineered EV platforms for targeted therapy; and (5) biomarkers for neurodegenerative diseases (Alzheimer's disease, Parkinson's disease). Standardization efforts, including calibration of flow cytometers and development of GMP-compliant production methods, are critical for clinical translation. The field is addressing key challenges including EV heterogeneity, scalable production, and reproducible characterization methods.