Natasa Zarovni

The stall in clinical translation of extracellular vesicle (EV) therapeutics requires addressing critical and hidden causes of attrition and delays. Despite more than 150 registered clinical trials and fifteen years of clinical investigation, small EV (sEV) therapeutics have yielded zero FDA approvals—a translational deficit that has received remarkably little quantitative scrutiny. We systematically evaluated 783 EV-related clinical trials (152 of which therapeutic) registered through December 2025, benchmarking the sEV pipeline against 1,131 CAR-T cell therapy trials (ex-China) that share the “process is the product” manufacturing constraint, yet have delivered six FDA-approved products. A quality–failure paradox emerges, in which industry-sponsored sEV trials exhibit 39% higher composite methodological quality (quality index 2.49 vs. 1.79) yet fail at approximately five-fold the rate of academic programmes (28.6% vs. 5.1%; OR=7.40, 95% CI 2.5–22.3, p=0.0004). Cross-modality replication in CAR-T trials confirms the direction of this association (OR=2.51, p<0.001; Cochran– Mantel–Haenszel pooled OR=2.76, p<0.001). Registry abandonment—affecting 24% of academic sEV trials—constitutes a hidden failure mode that, when reclassified, dissolves the apparent paradox. Premature clinical entry of incompletely defined products, rather than insufficient methodological rigour, represents the central constraint on sEV translational progress. The opacity of research data, inadequate pre clinical evaluation, and failure to report negative (null) findings in clinical trials create a hidden crisis that drains hundreds of millions invested by public and private sector—eroding the return on investment—and traps progress in cycles of duplicated effort, wasteful resource allocation, and missed learning opportunities.

Extracellular vesicles (EVs) of human origin show promise for regenerative medicine and wound healing. However, they have limitations regarding scalability, variability, safety, and costs. Plant-derived EVs may represent a valid alternative. This study investigated the regenerative potential of EVs extracted from orange juice (oEVs). oEVs obtained by standard ultracentrifugation were compared with oEVs purified by tangential flow filtration (TFF), a scalable technique suitable for large-scale and regulatory-compliant manufacturing. Comparisons included size, morphology, pH, Zeta potential, protein and RNA content, Raman spectroscopy, and proteomic, metabolomic, and RNA sequencing. The regenerative potential of oEVs was tested in vitro, with cell migration, endothelial tube formation, and proliferation assays performed. Antioxidant ability was tested on endothelial cells stressed by hyperglycemia or pro-inflammatory cytokine cocktails. Next, oEVs were formulated with different hydrogels and tested at different doses on skin ulcers on healthy and diabetic mice. TFF oEVs showed the same physio-chemical characteristics and a comparable molecular content as those isolated by ultracentrifugation, confirming the path to scalability. In vitro oEVs promoted cell migration, formation of capillary-like structures, cell proliferation, and strong antioxidant activity. Moreover, oEVs effectively accelerated in vivo wound closure in healthy and diabetic mice. Thus, oEVs may provide a useful and cost-effective ingredient for improved and effective wound treatment strategies.

Plant-derived extracellular vesicles (EVs) have shown numerous health benefits, including modulation of the human gut microbiota. Hereby, we employed isothermal microcalorimetry (IMC) to explore the effects of ginger-derived nanovesicles (G-NVs) on the growth and metabolic activity of Bacteroides thetaiotaomicron ( Bt ), a dominant saccharolytic commensal with promising next-generation probiotic potential. Bt was exposed to either G-NVs or the ginger extract separated from G-NVs (G-CTL) in defined media under anaerobic conditions. Both ginger samples enhanced bacterial specific growth rate and maximum metabolic activity, inducing the latter earlier. However, higher biomass production and greater secretion of acetic, succinic, and propionic acids occurred only in response to the G-CTL. Complete sugar depletion and unchanged FAA levels indicated preferential carbohydrate utilization by Bt . Overall, these findings revealed that Bt ′s metabolic state is shaped by both G-NVs and G-CTL, yet through distinct mechanisms, with G-NVs inducing rapid stimulation without increasing total metabolic output and G-CTL providing a sustained, dose-dependent effect. To our knowledge, this is the first study applying IMC to monitor real-time the impact of EVs on microbial growth and metabolism, underscoring IMC′s utility for mechanistic studies of EV-microbe interactions. Furthermore, this research sets the ground for innovative strategies in nutraceutical and microbiome-targeted therapy development.

Extracellular Vesicles (EVs) from seminal plasma have achieved attention due to their potential physiopathological role in male reproductive systems. This study employed a comprehensive proteomic and transcriptomic approach to investigate the composition and molecular signatures of EVs isolated from human seminal plasma. EVs from Normozoospermic (NORMO), OligoAsthenoTeratozoospermic (OAT), and Azoospermic (AZO) subjects were isolated using a modified polymer precipitation-based protocol and characterized for size and morphology. Comprehensive proteomic analysis, using both gel-free and gel-based approaches, revealed distinct protein profiles in each group (p<0.01), highlighting potential molecules and pathways involved in sperm function and fertility. The data are available via ProteomeXchange with identifiers PXD051361 and PXD051390, respectively. Transcriptomic analysis confirmed the trend of a general downregulation of AZO and OAT compared to NORMO shedding light on regulatory mechanisms of sperm development. Bioinformatic tools were applied for functional omics analysis; the integration of proteomic and transcriptomic data provided a comprehensive understanding of the cargo content and regulatory networks present in EVs. This study contributes to elucidating the key role of EVs in the paracrine communication regulating spermatogenesis. A full understanding of these pathways not only suggests potential mechanisms regulating male fertility but also offers new insights into the development of diagnostic tools targeting male reproductive disorders.

Background: Platelet-derived Extracellular Vesicles, or “Platelet Dust” (PD), are reported as the most-abundant extracellular vesicles in plasma. However, the PD molecular content, especially the small RNA profile, is still poorly characterized. This study aims to characterize PD and other extracellular vesicles (EVs) in patients with non-small-cell lung cancer (NSCLC), focusing on their small RNA signatures and diagnostic potential. Methods: The EVs were isolated directly from the plasma of healthy donors and patients with NSCLC using the surface markers CD9, CD63, CD81 (overall EVs), and CD61 (PD). Small RNA sequencing was then performed to comprehensively profile the miRNAs. Results: Our analysis revealed distinct small RNA profiles in the EVs and the PD from the patients with NSCLC. The EVs (CD9-, CD63-, and CD81-positive) showed the enrichment of four miRNAs and the depletion of ten miRNAs, while the PD (CD61-positive) exhibited a more complex profile, with nineteen miRNAs enriched and nine miRNAs depleted in the patients with NSCLC compared to those of the healthy controls. Conclusions: This exploratory study enhances our understanding of miRNA composition within different plasma vesicle populations, shedding light on the biology of plasma vesicles and their contents. Furthermore, utilizing an extracellular vesicle isolation method with potential clinical applicability offers the prospect of improved cancer characterization and detection by selecting the most informative subpopulation of plasma vesicles.

Due to their intercellular communication properties and involvement in a wide range of biological processes, extracellular vesicles (EVs) are increasingly being studied and exploited for different applications. Nevertheless, their complex nature and heterogeneity, as well as the challenges related to their purification and characterization procedures, require a cautious assessment of the qualitative and quantitative parameters that need to be monitored. This translates into a multitude of choices and putative solutions that any EV researcher must confront in both research and translational environments. In this respect, decision‐making tools may help assess various options, weigh pros and cons, and ultimately arrive at a thought‐out decision that considers both the best fit‐to‐source and fit‐to‐scope EV application(s). Here, we present a multi‐criteria EV decision‐making grid (EV‐DMG) as a novel, efficient, customizable, and easy‐to‐use tool to support EV research and innovation. By identifying and weighing key assessment criteria for comparing distinct EV‐based preparations and related processes, our EV‐DMG may assist any EV community member in making informed, traceable, and reproducible decisions regarding the management of EV sources or samples. Ultimately, this EV‐DMG may guide the adoption of the most suitable EV production and analytical pipelines for targeting a defined aim or application.

Stochiometric issues, encompassing both the quantity and heterogeneity of extracellular vesicles (EVs) derived from tumor or other tissues in blood, pose important challenges across various stages of biomarker discovery and detection, affecting the integrity of data, introducing losses and artifacts during blood processing, EV purification, and analysis. These challenges shape the diagnostic utility of EVs especially within the framework of established and emerging methodologies. By addressing these challenges, we aim to delineate crucial parameters and requirements for tumor-specific EV detection, or more precisely, for tumor identification via EV based assays. Our endeavor involves a comprehensive examination of the layers that mask or confound the traceability of EV markers such as nucleic acids and proteins, and focus on "Low abundance - low occupancy" scenario. Finally, we evaluate the advantages vs. limitations of digital technologies over more conventional bulk assays, suggesting that the combined use of both to capture and interpret the EV signals, in particular the EV surface displayed proteins, may ultimately provide quantitative information on their absolute abundance and distribution.

Current state-of-the-art tools for analyzing extracellular vesicles (EVs) offer either highly sensitive but unidimensional bulk measurements of EV components, or high-resolution multiparametric single particle analyses which lack standardization and appropriate reference materials. This limits the accuracy of assessment of marker abundance and overall marker distribution among individual EVs, and finally, the understanding of true EV heterogeneity. In this study, we aimed to define the standardized operating procedures and reference material for fluorescent characterization of EVs with two commonly used EV analytical platforms - nanoparticle tracking analysis (NTA) and nano-flow cytometry (nFCM). For the first time, we achieved quantitative fluorescence analyses on ZetaView NTA and NanoAnalyzer nFCM instruments, by utilizing yellow-green FluoSpheres (FS) with assigned ERF (equivalent reference fluorophore) values. This standardization technique allowed for fluorescent EV signal to be expressed in ERF units (indicative of bound fluorescent antibodies per EV), thus enabling measurement of target protein marker abundance on individual EVs, and in the whole EV population. The NTA’s and nFCM’s limits of quantification (LoQ) were evaluated at 115 and 75 Alexa Fluor 488 (AF488) molecules, respectively. To complement these shortcomings, in-line bulk fluorescence measurements in a plate reader were performed. This provided absolute marker quantification, and more insightful analyses of EV heterogeneity and marker stoichiometry. The standardization method outlined in this work unlocks the full analytical potential of NTA and nFCM, enabling cross-platform data comparison. At the same time, it highlights some of the technical challenges and considerations, and thus contributes to the ongoing efforts towards development of EV analytical tools.