Minimal information for studies of extracellular vesicles 2018 (MISEV2018): a position statement of the International Society for Extracellular Vesicles and update of the MISEV2014 guidelines

Enhancing cardiac regeneration: direct reprogramming of fibroblasts into myocardial-like cells using extracellular vesicles secreted by cardiomyocytes

To investigate the promoting effect of extracellular vesicles derived from myocardial cells (CM-EVs) on the reprogramming of cardiac fibroblasts (CFs) into cardiomyocyte-like cells (iCMs) and their therapeutic effect on myocardial infarction (MI) in rats. Cell experiments: The differential adhesion method was used to obtain Sprague Dawley (SD) suckling rat CFs and cardiomyocytes (CMs), while the ultracentrifugation method was used to obtain CM-EVs. Transmission electron microscopy and nanoparticle tracking technology were used to analyze and determine the morphology and particle size of CM-EVs. Western blotting was used to identify the expression of EV markers CD9, CD63, and Alix proteins. Small molecule combination of CHIR99021, Forskolin, Dorsomorphin, SB431542, and Valproic acid (CFDSV) and CFDSV + CM-EVs combination were used to induce CFs to differentiate into cardiomyocytes. The expression of cellular morphological changes, myocardial-specific protein cardiac troponin T (cTnT), and α-actinin were detected on the 3rd, 6th, 9th, and 15th day of reprogramming, respectively. After transfection and inhibition of miRNA-133, immunofluorescence, RT-qPCR, and Western blotting techniques were used to detect the expression of cTnT and α-actinin of induced CFs in the CMs group (CM-EVs), miRNA-133 high expression group (133H), and miRNA-133 inhibition group (133I). Animal experiment: CM-EVs were injected into the margin of myocardial infarction in rats. Cardiac function was detected by echocardiography before and 4 weeks after infarction, and the pathological changes were detected by HE and Masson staining, while Tunel and CD31 fluorescence staining were used to detect myocardial cell apoptosis and angiogenesis. CFs in the CM-EVs group expressed cTnT and α-actinin after induction, and the expression intensity gradually increased with the extension of induction time. On the 15th day after induction, cTnT-positive cells accounted for 85.6% of the total cell count, while the CFDSV group accounted for 48.8%. The majority of cells expressed GATA-binding protein 4 (GATA4), NK2 homeobox 5 (Nkx-2.5), and connexin 43 (Cx43). The RT-qPCR analysis showed the induced CFs expressed mature cardiomyocyte markers, including cTnT, Ryr2, Nkx-2.5, and GATA, which were similar to those of CMs (P < 0.05). Upon induction of CFs into iCMs, iCMs expressed cardiac precursor cell markers, such as source domain transcription factor-1 (Isl-1), mesodermal posterior spiral transcription factor-1 (Mesp-1), GATA4, and fetal liver kinase-1 (Flk-1). RT-qPCR, Western blotting, and immunofluorescence results showed that cTnT and α-actinin were highly expressed in CFs induced by CM-EVs group and 133H group until the 15th day, while the expression levels were low in cont group and 133I group. In animal in vivo experiments, injection of CM-EVs was found to alleviate myocardial fibrosis and reduce apoptosis of myocardial cells in the infarcted area compared to the MI group (P < 0.001). Moreover, there was an increase in capillary density. Results showed a significant improvement in left ventricular ejection fraction and fractional shortening after 4 weeks of CM-EVs injection (P < 0.01). CM-EVs can enhance the reprogramming efficiency of CFs into iCMs, effectively alleviate myocardial fibrosis, resist cell apoptosis, increase angiogenesis, and improve heart function after myocardial infarction. MiRNA-133 plays an important regulatory role in this process.

Advances in the study of extracellular vesicles of Naegleria fowleri and their role in contact-independent pathogenic mechanisms

BACKGROUND

Extracellular vesicles (EVs) are spherical membrane particles released by prokaryotic and eukaryotic cells. EVs produced by pathogenic organisms are known to play a role in host-pathogen interactions; however, despite some reports on Naegleria fowleri EVs, their potential role in inducing cytopathic effects remains poorly understood. In this study, we evaluated the role of N. fowleri EVs in contact-independent pathogenic mechanisms.

METHODS

Extracellular vesicles were characterized via transmission electron microscopy, nanoparticle tracking analysis, SDS-PAGE, mass spectrometry, Western blotting, and zymography. EVs internalization by trophozoites and MDCK epithelial cells was also determined. Finally, mammalian cells were coincubated with EVs to evaluate haemolytic activity, epithelial paracellular ionic permeability alterations, and necrosis.

RESULTS

Naegleria fowleri extracellular vesicles, ranging from 82.5 to 576.5 nm in size, were isolated, with a mean of 216.8 nm and a mode of 165.3 nm. Proteomic analysis identified 1006 proteins in the EVs, including leishmanolysin, a protein associated with pathogenic mechanisms such as adhesion and enzymatic processes. The proteolytic activity of EVs was found to be primarily due to serine protease. Furthermore, EVs were internalized by both trophozoites and MDCK cells. Additionally, EVs exhibited haemolytic activity in erythrocytes as well as increased ionic permeability and necrosis in MDCK cells 24 h postinteraction.

CONCLUSIONS

Naegleria fowleri EVs exhibit proteolytic and haemolytic activity and are internalized by trophozoites and MDCK epithelial cell monolayers, increasing the ionic permeability of the monolayer and inducing necrosis. Furthermore, these vesicles contain molecules associated with pathogenic processes such as leishmanolysin. Our results suggest that EVs facilitate paracellular invasion, migration, and damage caused by trophozoites and play a significant role in pathogenic processes as part of a contact-independent mechanism, which, in conjunction with a contact-dependent mechanism, enhances our understanding of the pathogenicity exhibited by this amphizoic amoeba during its invasion of target tissues.

Acute respiratory distress vs healthy lung environments differently affect mesenchymal stromal cell extracellular vesicle miRNAs

The acute respiratory distress syndrome (ARDS) inflammatory environment alters mesenchymal stromal cell (MSC) gene and protein expression but effects on microRNA (miRNA) content of MSC-extracellular vesicle (EVs) remain unknown. To assess this, sequencing analysis of EV-miRNAs prepared from human bone marrow-derived MSCs (hMSCs) exposed ex vivo to bronchoalveolar lavage fluid (BALF) from ARDS patients or healthy volunteers (HV) identified a number of differentially expressed miRNAs. Discriminant, differential expression, and functional enrichment analyses identified 14 miRNAs significantly changed following ARDS versus HV BALF exposure. Network analysis showed 4 (miR-760, miR-3175, miR-885-3p, and miR-766-3p) of the 14 EV-miRNAs formed a regulatory "hub", suggesting co-targeting of specific gene pathways. In silico prediction identified a number of pathways important in lung injury. Two miRNAs involved in regulation of the cystic fibrosis transmembrane conductance regulator (CFTR), miRNA-145-5p and miRNA-138-5p, were also significantly increased in ARDS BALF-exposed hMSCs EVs. Functionally, EVs from hMSCs exposed to either ARDS or HV BALF had differential effects on CFTR Cl- secretion by cultured primary human bronchial epithelial cells, an effect predicted to reduce mucociliary clearance. The potential clinical impact of these finding highlights the need for further studies assessing the role of hMSC-EV miRNAs in regulating lung inflammation and mucociliary clearance.

Tissue Engineering and Regenerative Medicine: Perspectives and Challenges

From the pioneering days of cell therapy to the achievement of bioprinting organs, tissue engineering, and regenerative medicine have seen tremendous technological advancements, offering solutions for restoring damaged tissues and organs. However, only a few products and technologies have received United States Food and Drug Administration approval. This review highlights significant progress in cell therapy, extracellular vesicle-based therapy, and tissue engineering. Hematopoietic stem cell transplantation is a powerful tool for treating many diseases, especially hematological malignancies. Mesenchymal stem cells have been extensively studied. The discovery of induced pluripotent stem cells has revolutionized disease modeling and regenerative applications, paving the way for personalized medicine. Gene therapy represents an innovative approach to the treatment of genetic disorders. Additionally, extracellular vesicle-based therapies have emerged as rising stars, offering promising solutions in diagnostics, cell-free therapeutics, drug delivery, and targeted therapy. Advances in tissue engineering enable complex tissue constructs, further transforming the field. Despite these advancements, many technical, ethical, and regulatory challenges remain. This review addresses the current bottlenecks, emphasizing novel technologies and interdisciplinary research to overcome these hurdles. Standardizing practices and conducting clinical trials will balance innovation and regulation, improving patient outcomes and quality of life.

Non-Specific Particle Formation During Extracellular Vesicle Labelling With the Lipophilic Membrane Dye PKH26

Current approaches for the fluorescent labelling of extracellular vesicles (EVs) have been reported to produce widely variable and controversial results, highlighting a significant need for validated, reproducible labelling methods to advance the field of EV research. Lipophilic membrane dyes are commonly used but have been shown to produce non-specific fluorescent particles that are indistinguishable from labelled EVs, confounding experimental results. We aimed to distinguish conditions that can either promote or reduce the formation of non-specific dye particles when using the prototypical lipophilic membrane dye PKH26. We optimised a labelling approach that minimises the production of non-specific dye particles by altering buffer conditions during staining and validated this method across cell-based and in vivo systems of EV biodistribution. To do this, we specifically isolated small EVs using ultrafiltration and size exclusion chromatography and validated sample purity and post-isolation processing steps. We then used single-EV spectral flow cytometry and transmission electron microscopy to investigate the impact of four different buffer conditions on PKH26 non-specific particle formation. We also determined the extent to which non-specific PKH26 particles were detectable in cell-based assays and in vivo within mouse lymph nodes using flow cytometry, immunofluorescence, and intravital imaging. By optimising buffer conditions to eliminate additional protein, we were able to minimise the formation of dye aggregates while maintaining efficient EV labelling, producing a much higher signal-to-noise ratio both in vitro and in vivo. We also demonstrate that failure to include proper vehicle controls can have significant implications on experimental results, leading to false positive data. This work emphasizes the importance of adequately benchmarking EV labelling approaches as it is essential for accurate evaluation of EV trafficking in physiologic and pathologic states.

Nano-Flow Cytometry-Guided Discrimination and Separation of Human Cytomegalovirus Virions and Extracellular Vesicles

Accurate quantification and physical separation of viral particles and extracellular vesicles (EVs) produced by virus-infected cells presents a significant challenge due to their overlapping physical and biochemical properties. Most analytical methods provide information on a particle mixture as a whole, without distinguishing viral particles from EVs. By utilising nano-flow cytometry (nFC), a specialised form of flow cytometry adapted for the investigation of nanoparticles, we developed a simple, nucleic acid staining-based method for discrimination and simultaneous quantification of the human cytomegalovirus (HCMV) virions, dense bodies and EVs, within extracellular particle mixtures produced by HCMV-infected cells. We show that nucleic acid staining allows for discrimination of the individual particle types based on their distinct fluorescence/side scatter profiles, assessed at single-particle level by nFC. Following this, we optimised a method for physical separation of EVs from viral particles, based on high-speed centrifugation through density cushions, using nFC as a tool to evaluate the purity of the isolated EVs. The methods introduced here have the capacity to circumvent common difficulties associated with the co-investigation of EVs and viruses.

The biological roles of exosome-encapsulated traditional Chinese medicine monomers in neuronal disorders

A traditional Chinese medicine (TCM) monomer is a bioactive compound extracted from Chinese herbal medicines possessing determined biological activity and pharmacological effects, and has gained much attention for treating neuronal diseases. However, the application of TCM monomers is limited by their low solubility and poor ability to cross the blood-brain barrier (BBB). Exosomes are small extracellular vesicles (EVs) ranging in size from 30 to 150 nm in diameter and can be used as drug delivery carriers that directly target cells or tissues with unique advantages, including low toxicity, low immunogenicity, high stability in blood, and the ability to cross the BBB. This review discusses the biogenesis, components, stability, surface modification, isolation technology, advantages, and disadvantages of exosomes as drug carriers and compares exosomes and other similar drug delivery systems. Furthermore, exosome-encapsulated TCM monomers exert neuroprotective roles, such as anti-inflammation, anti-apoptosis, anti-mitophagy, and anti-oxidation, in various neuronal diseases, including Alzheimer's disease (AD), Parkinson's disease (PD), multiple sclerosis (MS), and cerebral ischemia and reperfusion (CI/R) injury, as well as anti-drug resistance, anti-tumorigenesis, anti-angiogenesis, and promotion of apoptosis in brain tumors, providing more inspiration to promote the development of an exosome-based delivery tool in targeted therapy for neuronal diseases.

Development of a Recombinant Outer Membrane Vesicles (OMVs)-Based Vaccine Against Helicobacter pylori Infection in Mice

The current vaccine development for Helicobacter pylori (H. pylori) still faces challenges of weak immune responses stimulated by existing antigens and a lack of safe adjuvants. The modification of the lipopolysaccharide (LPS) structure by H. pylori is an important mechanism involved in its immune escape. In this study, we developed a novel recombinant vaccine candidate against H. pylori infection by knocking down the key genes (lpxE, lpxF and futB) of LPS modification and employing the bacterial outer membrane vesicles (OMVs) as a vector for delivering UreB, VacA and CagA antigens, and then evaluated its safety and immune protective efficacy in vitro and in vivo mouse model. We measured the antibody and cytokine productions, detected the subtypes of immune cells, and examined the histopathological changes in mice from the control and various experimental groups. We revealed that this OMV-based recombinant vaccine candidate could induce specific humoral immune responses and a Th1/Th2/Th17 mixed immune response, with Th17 being predominant, and markedly protect the mice from H. pylori infection. Our findings suggest that the OMVs with the genetically engineered LPS may function as a vector for delivering recombinant antigens and safe adjuvants for the development of novel vaccine candidates against H. pylori infection.

Exosomes: the next-generation therapeutic platform for ischemic stroke

Current therapeutic strategies for ischemic stroke fall short of the desired objective of neurological functional recovery. Therefore, there is an urgent need to develop new methods for the treatment of this condition. Exosomes are natural cell-derived vesicles that mediate signal transduction between cells under physiological and pathological conditions. They have low immunogenicity, good stability, high delivery efficiency, and the ability to cross the blood-brain barrier. These physiological properties of exosomes have the potential to lead to new breakthroughs in the treatment of ischemic stroke. The rapid development of nanotechnology has advanced the application of engineered exosomes, which can effectively improve targeting ability, enhance therapeutic efficacy, and minimize the dosages needed. Advances in technology have also driven clinical translational research on exosomes. In this review, we describe the therapeutic effects of exosomes and their positive roles in current treatment strategies for ischemic stroke, including their anti-inflammation, anti-apoptosis, autophagy-regulation, angiogenesis, neurogenesis, and glial scar formation reduction effects. However, it is worth noting that, despite their significant therapeutic potential, there remains a dearth of standardized characterization methods and efficient isolation techniques capable of producing highly purified exosomes. Future optimization strategies should prioritize the exploration of suitable isolation techniques and the establishment of unified workflows to effectively harness exosomes for diagnostic or therapeutic applications in ischemic stroke. Ultimately, our review aims to summarize our understanding of exosome-based treatment prospects in ischemic stroke and foster innovative ideas for the development of exosome-based therapies.

CD9-enriched extracellular vesicles from chemically reprogrammed basal progenitors of salivary glands mitigate salivary gland fibrosis

Extracellular vesicles (EVs) derived from stem cells offer promising potential for cell-free therapy. However, refining their cargo for precise disease targeting and delivery remains challenging. This study employed chemical reprogramming via dual inhibition of transforming growth factor beta (TGFβ) and bone morphogenetic protein (BMP) to expand salivary gland basal progenitor cells (sgBPCs). CD9-enriched (CD9+) EVs were then isolated from the sgBPC secretome concentrate using a dual microfluidic chip. Notably, CD9+ EVs demonstrated superior uptake by salivary epithelial cells compared to CD9-depleted (CD9-) EVs and total EVs. In vivo studies using a salivary gland (SG) obstruction mouse model and ex vivo studies in SG fibrosis organoids revealed that CD9+ EVs significantly enhanced anti-fibrotic effects over CD9- EVs and control treatments. The presence of miR-3162 and miR-1290 in CD9+ EVs supported their anti-fibrotic properties by downregulating ACVR1 expression. The chemical reprogramming culture method effectively expanded sgBPCs, enabling consistent and scalable EV production. Utilizing microfluidic chip-isolated CD9+ EVs and ductal delivery presents a targeted and efficient approach for anti-fibrotic SG regeneration.

Characterization of Extracellular Vesicles Derived From Human Precision-Cut Liver Slices in Metabolic Dysfunction-Associated Steatotic Liver Disease

Extracellular vesicles (EVs) are cell-produced, membrane-surrounded vesicles that harbour the biological features of donor cells. In the current study, we are the first to isolate and characterize EVs isolated from human precision-cut liver slices (PCLS), obtained from both healthy and metabolic dysfunction-associated steatohepatitis (MASH) cirrhotic livers. PCLS derived from patients can faithfully represent disease conditions in humans. EVs were isolated from human PCLS after incubating in normal medium or modified medium that mimics the pathophysiological environment of metabolic dysfunction associated liver disease (MASLD). MASH PCLS produced higher amounts of EVs compared to healthy PCLS (p < 0.001). Mass spectrometry revealed that around 300 proteins were significantly different in EVs derived from MASH PCLS versus healthy PCLS (FDR < 0.05), irrespective of the type of medium. Significantly changed EV proteins were largely involved in signalling receptor binding function and showed potential in promoting fibrosis. In the liver, these ligand-associated receptors are highly expressed in hepatic stellate cells, and the MASH EVs functionally promoted the activation of hepatic stellate cells. Furthermore, the amounts of EpCAM and ITGA3 in EVs were positively associated with the progression of MASLD, which suggests the use of liver-derived EVs as potential biomarkers for MASLD. Characterization of EVs derived from human PCLS may assist future studies in investigating the pathogenesis and identifying liver-specific EVs as biomarkers of MASLD.

[Typical strategy and research progress of efficient isolation methods of exosomes based on affinity interaction]

Exosomes form a subclass of extracellular vesicle that are secreted by most cells and found in nearly all body fluids, including blood, urine, saliva, amniotic fluid, and milk, as well as in various tissues and intercellular spaces. Exosomes have recently been recognized as crucial intercellular communication mediators, and an increasing number of studies have shown that exosomes are important liquid-biopsy tools that play irreplaceable roles in the diagnosis, prognosis, and treatment of diseases. The ability to isolate high-quality exosomes is a prerequisite for diagnosing and subsequently treating diseases in an accurate and repeatable manner. However, efficiently isolating exosomes from complex biological samples is challenging owing to their relatively low abundances and interference from non-vesicular macromolecules (such as cell debris and proteins). To date, various isolation techniques based on the physical, chemical, and biological characteristics of exosomes have been developed. Indeed, efficient affinity-interaction-based methods have recently overcome the limitations and drawbacks of traditional exosome isolation methods and are widely used in scientific research and clinical applications. This review focuses on exosome isolation and enrichment, and systematically reviews recent research progress on efficient isolation methods based on affinity interactions. Developmental prospects of exosome isolation and enrichment directions are analyzed with the aim of providing a reference for the construction and use of new exosome-isolation strategies.

Extracellular Vesicles and Immune Activation in Solid Organ Transplantation: The Impact of Immunosuppression

Recent advances in extracellular vesicle (EV) research in organ transplantation have highlighted the crucial role of donor-derived EVs in triggering alloimmune responses, ultimately contributing to transplant rejection. Following transplantation, EVs carrying donor major histocompatibility complex (MHC) molecules activate recipient antigen-presenting cells (APCs), initiating both alloreactive and regulatory T-cell responses. While immunosuppressive drugs are essential for preventing rejection, they may also influence the biogenesis and release of EVs from donor cells. This review examines the impact of maintenance immunosuppressive therapy on EV biogenesis and release post-transplantation. In addition, EV release and uptake may be influenced by specific factors such as the patient's end-stage organ disease and the transplant procedure itself. In-vitro studies using primary human parenchymal and immune cells-integrated with cutting-edge multi-omics techniques, including genomics, proteomics, lipidomics, and single-EV analysis-will offer deeper insights into EV biology and the mechanisms by which immunosuppressive agents regulate EV-initiated immune processes. A detailed understanding of how organ failure, the transplantation procedure and immunosuppressive drugs affect the biology of EVs may uncover new roles for EVs in immune activation and regulation in patients, ultimately leading to improved immunosuppressive strategies and better transplant outcomes.

Plant-derived nanovesicles and therapeutic application

Plant-derived nanovesicles (PDNVs) are becoming more popular as promising therapeutic tools owing to their diversity, cost-effectiveness, and biocompatibility with very low toxicity. Therefore, this review aims to discuss the methods for isolating and characterizing PDNVs and emphasize their versatile roles in direct therapeutic applications and drug delivery systems. Their ability to effectively encapsulate and deliver large nucleic acids, proteins, and small-molecule drugs was highlighted. Moreover, advanced engineering strategies, such as surface modification and fusion with other vesicles, have been developed to enhance the therapeutic effects of PDNVs. Additionally, we describe key challenges related to this field, encouraging further research to optimize PDNVs for various clinical applications for prevention and therapeutic purposes. The distinctive properties and diverse applications of PDNVs could play a crucial role in the future of personalized medicine, fostering the development of innovative therapeutic strategies.

Trauma and Sensory Systems: Biological Mechanisms Involving the Skin and the 17q21 Gene Cluster

Childhood trauma experience increases risk for neuropsychiatric and neurodevelopmental disorders, including posttraumatic stress disorder, autism spectrum disorder, and attention-deficit/hyperactivity disorder. While the biological mechanisms connecting adverse experiences with later disease presentation are not clear, the concept of gene × environment × development interactions has significant implications for improving our understanding of these diseases. We recently used this approach in a study where we found that women exposed to interpersonal violence trauma (environment) uniquely during adolescence (development), but not childhood or adulthood, had novel protein biomarkers (gene) associated with a sensory cell system in the skin, Merkel cells. Merkel cell mechanosensory signaling is important in gentle and social touch, inflammation-induced pain, and the neuroendocrine stress response of the skin. Further, keratinocyte-derived Merkel cell final maturation occurs during the identified vulnerable period of adolescence. Interestingly, many of the genes identified in our study belong to a known 17q21 gene cluster, suggesting an identifiable location in the genome permanently altered by adolescent trauma. These results form a potential functional link between mechanosensory Merkel cells and the pathology and sensory symptoms in posttraumatic stress disorder. Future research directions could identify specific mechanisms involved in tactile alterations following trauma in hopes of revealing additional biomarkers and potentially leading to novel tactile-involved therapies (e.g., massage, electroacupuncture, or focused ultrasound).

Mesenchymal Stem Cell-Derived Extracellular Vesicles Improve Survival and Enhance Hematopoietic Recovery in Mice Exposed to High-Dose Irradiation

Exposure to high-dose radiation often results in hematopoietic acute radiation syndromes, leading to early mortality, while current therapies for patients exposed to lethal radiation doses are limited. Mesenchymal stem cell-derived extracellular vesicles (MSC-EVs) have shown promise in tissue repair and regeneration but have not been well investigated for mitigating high-dose radiation damage. We previously demonstrated that human or murine MSC-EVs can reverse bone marrow injury caused by mild or moderate radiation. The current study evaluated the therapeutic potential of human MSC-EVs in mice exposed to high-dose total body irradiation (TBI). Mice were exposed to 0, 700, or 950 cGy TBI and subsequently received daily intravenous MSC-EV injections (1 × 109 particles) for 3 days postirradiation. We evaluated survival rates, peripheral blood recovery, bone marrow engraftment, and bone marrow gene expression profiles at various intervals following treatment. MSC-EV administration significantly enhanced survival, with 70% of treated mice surviving 120 days after 950 cGy TBI exposure, compared with 0% survival in untreated controls by day 30. Although early peripheral blood recovery was not observed within 14 days, MSC-EV treatment facilitated substantial recovery at 3 months postirradiation, with significant increases in red blood cell, platelet, white blood cell, and hemoglobin levels, despite white blood cell and hemoglobin levels remaining slightly below normal. Furthermore, the engraftment capacity of bone marrow stem cells was significantly improved. The changes in hematopoietic-related gene expression presented at 14 days postirradiation returned to normal levels by 120 days in MSC-EV-treated mice. These results highlight the potential of MSC-EVs as a therapeutic strategy for high-dose radiation injuries by promoting hematopoietic recovery and improving survival. Our future research will focus on elucidating the radioprotective mechanisms and investigating their integration with existing therapies.

Extracellular Vesicle-Mediated Delivery of 20S Proteasomes Enhances Tau Degradation in Recipient Cells

The 26S proteasome holoenzyme comprises 20S catalytic and 19S regulatory complexes. Accumulating evidence suggests that the majority of proteasomes in the extracellular space exist as free 20S proteasomes; however, their origin and pathophysiological function remain to be determined. Here, we report that cellular proteasomes are effectively packaged into the lumen of extracellular vesicles (EVs) and secreted in a structurally intact and enzymatically active 20S form. We further demonstrate that EV-encapsulated 20S proteasomes are delivered to recipient cells and facilitate the degradation of overexpressed tau proteins without disrupting global proteolytic pathways. These findings highlight a novel cell-to-cell communication system that transports the proteasomes to target cells for the clearance of proteotoxic substrates. Further characterisation of this homeostatic mechanism will improve our understanding of organismal stress response mechanisms and may provide a therapeutic approach to treat various proteinopathies, including Alzheimer's disease.

Proteomics analysis of extracellular vesicles during Vibrio anguillarum infection in lumpfish (Cyclopterus lumpus)

Lumpfish (Cyclopterus lumpus) is a native fish of the North Atlantic Ocean used as sea lice biocontrol in Atlantic salmon farms. Lumpfish also has been used as model for marine infectious diseases and immunity. Lumpfish is susceptible to Vibrio anguillarum infection, and upon infection, lumpfish immunity is activated to preclude the disease progression. Extracellular vesicles (EVs) play an important role in early immune cellular communication. Lumpfish EVs and their potential role in immunity have not been explored. Herein, EVs where isolated from serum of naïve lumpfish and from lumpfish infected with V. anguillarum at 5 and 10 days post infection (dpi). EVs characteristics were studied by electron microscopy and nanoparticle tracking, and protein cargo was analysed by Western blot and proteomic analysis. The isolated EVs showed a spherical shape ranging from ∼30 nm to 300 nm in diameter, but at 5 dpi the size variation was higher. A total of 395 proteins were identified. Upregulated proteins were linked to complement pathway/innate immunity, heme/iron binding, defense response to bacterium, apoptotic signaling pathway, and actin binding. Downregulated proteins were associated with ribonucleoprotein/ribosomal protein, transport and translation elongation factor activity, acute phase, protein phosphorylation and apoptotic process. Upon infection V. anguillarum infection, lumpfish EVs cargo was modified, from transporting metabolic proteins to proteins related to immunity. Characterization of peripheral lumpfish EVs protein profile during V. anguillarum infection provided with potential biomarkers repertoire that could be utilised in the development of novel tools to diagnose and control of V. anguillarum infection in finfish aquaculture.

Exosome-mediated communication between T cells and dendritic cells: Implications for therapeutic strategies

Cell communication is crucial for coordinating physiological functions in multicellular organisms, with exosomes playing a significant role. Exosomes mediate intercellular communication by transporting proteins, lipids, and nucleic acids between cells. These small, membrane-bound vesicles, derived from the endosomal pathway, are integral to various biological processes, including signal transmission and cellular behavior modulation. Recent advances highlight the potential of exosomes, especially dendritic cell-derived exosomes (DEXs), for diagnostic and therapeutic applications, particularly in cancer immunotherapy. DEXs are distinguished by their ability to present antigens and stimulate immune responses more effectively than exosomes from other cell types. They carry a cargo rich in immunostimulatory molecules and MHC-peptide complexes, which facilitate robust T-cell activation and enhance tumor-specific immune responses. The unique properties of DEXs, such as their ability to cross biological barriers and resist tumor-induced immunosuppression, position them as promising candidates for therapeutic applications. Here, I review the reports on the bidirectional interaction between dendritic cells and T cells through exosomes and their role in medicine.

On-treatment dynamics of circulating extracellular vesicles in the first-line setting of patients with advanced non-small cell lung cancer: the LEXOVE prospective study

Extracellular vesicle (EV) monitoring can complement clinical assessment of cancer response. In this study, patients with advanced non-small cell lung cancer (NSCLC) undergoing osimertinib, alectinib, pembrolizumab or platinum-based chemotherapy ± pembrolizumab were enrolled. EVs were characterized using Bradford assay to quantify the circulating cell-free EV protein content (cfEV), and dynamic light scattering to assess Rayleigh ratio excess at 90°, z-averaged hydrodynamic diameter and polydispersity index. A total of 135 plasma samples from 27 patients were collected at baseline (T0) and at the first radiological restaging (T1). A ∆cfEV < 20% was associated with improved median progression-free survival (mPFS) in responders versus non-responders. Specifically, cfEV responders on pembrolizumab had a significantly better mPFS (25.2 months) compared to those on chemotherapy plus pembrolizumab (6.1 months). EGFR-positive cfEV responders also experienced longer mPFS compared to cfEV non-responders (35.1 months, 95% CI: 14.9-35.5 vs. 20.8 months, 95% CI: 11.2-30.4). This study suggested that monitoring circulating EV could provide valuable insights into treatment efficacy in NSCLC, particularly for patients receiving pembrolizumab or osimertinib.

Immune cell-derived exosomal non-coding RNAs in tumor microenvironment: Biological functions and potential clinical applications

The intricate interactions between immune cells and tumors exert a profound influence on cancer progression and therapeutic efficacy. Within the tumor microenvironment, exosomes have emerged as pivotal mediators of intercellular communication, with their cargo of non-coding RNAs (ncRNAs) serving as key regulatory elements. This review examines the multifaceted roles of immune cell-derived exosomal ncRNAs in tumor biology. The involvement of various immune cells, including T cells, B cells, natural killer cells, macrophages, neutrophils, and myeloid-derived suppressor cells, in utilizing exosomal ncRNAs to regulate tumor initiation and progression is explored. Additionally, the biogenesis and delivery mechanisms of these immune cell-derived exosomal ncRNAs are discussed, alongside their potential clinical applications in cancer.

Cross-tissue MiRNA profiling of extracellular vesicles and PBMCs from amyotrophic lateral sclerosis patients

RNA-mediated toxicity, which can be controlled by alteration of gene expression, is considered a key event in Amyotrophic Lateral Sclerosis (ALS). Transcriptomic deregulation of miRNAs expression can spread via "horizontal" RNA transfer through extracellular vesicles (EVs) to act in conjunction with proteins, leading to changes in mRNA, which can provide early signals to indicate forthcoming neuropathological changes in the brain. The aim of this work is to compare expression profiles (obtained by miRNA-seq) from different tissues to highlight commonly expressed and tissue-specific miRNAs. miRNA species from plasma EVs were correlated with miRNA profiles obtained from peripheral blood mononuclear cells (PBMCs). Each tissue from ALS patients was compared to controls, revealing 159 deregulated (DE) miRNAs in Exosomes (EXOs), 247 DE miRNAs in PBMCs and 162 DE miRNAs in Microvesicles (MVs). Next, data were filtered to include only miRNAs expressed in disease samples (not in healthy subjects), to reduce the number of tissue- and ALS- specific miRNAs (EXO n = 22, MV = 11, PBMCs n = 8). We identified specific miRNAs and pathways related to each tissue. Interestingly, in PBMCs we found mainly neuro-linked pathways, such as neurotransmitters, brain and neuron development, while in EXOs, we found miRNAs implicated in MAPK and ERB signaling. In contrast, the altered pathways in MVs were not specific. This study shows that the composition of small RNA differs significantly between blood cells and its respective EVs fraction. Differentially expressed miRNAs can target definite transcripts in different cellular and molecular fractions. It is evident that, in terms of miRNAs cargo, MVs are not specific to ALS. Therefore, future studies will focus on the interaction between cells and EXOs.

Biofunctionalized nanomaterials for Parkinson's disease theranostics: potential for efficient PD biomarker detection and effective therapy

α-Synuclein (α-Syn) is a primary pathological indicator for Parkinson's disease (PD). The α-Syn oligomer is even more toxic and is responsible for PD. Hence, identifying α-Syn and its oligomers is an interesting approach to diagnosing PD. The prevention strategies for oligomer formation could be therapeutic in treating PD. Various conventional strategies have been developed for the management of PD. However, their clinical applications are limited due to toxicity, off-targeting, side effects, and poor bioavailability. Recently, nanomaterials have gained significant attention due to unique physicochemical characteristics such as nanoscale size, large surface area, flexibility of functionalization, and ability to protect and control a loaded payload. Functionalizing the surface of nanoparticles with a desired targeting agent could offer targeted delivery of the payload at the site of action due to specificity and selectivity against complementary molecules. Among various functionalization approaches, biomolecule-functionalized nanomaterials offer benefits such as enhanced bioavailability, improved internalization into target cells through receptor-mediated endocytosis, and delivery of therapeutics across the BBB (blood-brain barrier). In this review, we initially discussed the major milestones related to PD and highlighted the therapeutic strategies focused on clinical trials. The strategies of biomolecule functionalization of nanomaterials and their application in detecting and preventing α-Syn oligomer for the diagnosis and therapy of PD, respectively, have been reviewed comprehensively. Ultimately, we have outlined the conclusions, highlighted the limitations and challenges, and provided insight into future perspectives and alternative approaches that must be investigated.

The Radiosensitizing Effect of Tumor-Derived Microparticles Co-Loaded with Sorafenib and Gold Nanoparticles on Hepatocellular Carcinoma

Objective

Hepatocellular carcinoma (HCC) is a highly heterogeneous tumor with features such as high recurrence, easy metastasis, and poor prognosis, posing significant challenges for clinical treatment. In this study, we introduce a novel approach for treating HCC using tumor cell-derived microparticles (MPs) co-loaded with sorafenib and gold nanoparticles (AuNP) in combination with radiotherapy.

Methods

MPSF@AuNP was prepared by co-incubating AuNP with sorafenib, and was evaluated using dynamic light scattering (DLS), transmission electron microscopy (TEM), ultraviolet-visible spectrophotometry (UV-Vis), inductively coupled plasma optical emission spectrometry (ICP-OES), high-performance liquid chromatography (HPLC), and SDS-PAGE electrophoresis. Subsequently, their targeting ability toward hepatocellular carcinoma cells and their combined antitumor therapeutic effects with radiotherapy were investigated through in vitro and in vivo experiments, while their in vivo safety was also assessed.

Results

Our results demonstrate that co-loaded microparticles (MPSF@AuNP) can effectively deliver therapeutic agents to tumor cells through homologous targeting, improving the bioavailability of therapeutic drugs and enhancing their cytotoxicity against tumor cells. Furthermore, the combination of MPSF@AuNP with radiotherapy shows a synergistic anti-tumor effect by enhancing the inhibition of tumor cell proliferation, promoting tumor cell apoptosis, remodeling the tumor microenvironment, and activating the anti-tumor immune responses.

Conclusion

This study offers a promising treatment approach for malignant tumors such as HCC by using MP co-loaded and delivered with anti-tumor drugs and AuNP in combination with radiotherapy.

Extracellular vesicles in arbovirus infections: from basic biology to potential clinical applications

Arthropod-borne viruses, or arboviruses, are currently considered a global health threat responsible for potentially severe human diseases. The increased population density, changes in land use and climate change are some of the factors that are contributing to the spread of these infections over the last years. The pathogenesis of these diseases and the mechanisms of interaction with the host, especially those leading to the development of severe forms, are yet to be fully understood. In recent years extracellular vesicles (EVs) have emerged as important players in the inter-cellular and host-pathogen interaction arising a lot of interest also in the field of vector-borne viruses. In this context, EVs seem to play a dual role, by either promoting, thus facilitating, or preventing infection. Many studies are showing how viruses can hijack the vesiculation machinery to escape the host immune response and exploit EVs to sustain their replication and propagation, even though EVs shed by immune cells seem essential to promote antiviral responses. In this manuscript we reviewed the current knowledge regarding the association between EVs and vector-borne viruses, paying particular attention to their possible role in disease transmission and dissemination, as well as to their potential as novel tools for clinical applications, spanning from biomarkers of clinical utility to novel therapeutic options.

Extracellular vesicle biomarkers redefine prostate cancer radiotherapy

Radiotherapy (RT) remains a cornerstone in the treatment of prostate cancer (PCa). Extracellular vesicles (EVs), nano-sized particles secreted by cells, play important roles in intercellular communication within the tumour microenvironment (TME) and contribute to tumour growth, metastasis, and therapy resistance. Recent advancements demonstrate the potential of EVs as biomarkers for cancer diagnosis, prognosis, and treatment monitoring. Accumulating evidence supports the role of EVs in modulating RT outcomes by shaping the TME, mediating radioresistance, and influencing cancer metastasis. Despite substantial progress, challenges remain, including the heterogeneity of EV biogenesis, variability in cargo composition, and the absence of standardised methods for EV isolation and characterisation. While the therapeutic and diagnostic prospects of EVs in PCa management are promising, further research is needed to clarify the mechanisms through which EVs impact RT and to translate these findings into clinical practice. Incorporating EV research into PCa treatment paradigms could enhance diagnostic accuracy, enable real-time monitoring of RT responses, and support the development of new targeted therapeutic strategies. This review discusses recent progress in understanding EVs in the context of RT for PCa, focuses on their roles in modulating tumour growth, contributing to radioresistance within the TME, and facilitating the monitoring of RT efficacy and recurrence. In addition, the potential of EVs as biomarkers for liquid biopsy and their applications in enhancing radiosensitivity or overcoming radioresistance is also explored.

First trimester extravillous trophoblast secretes HLA class I molecules via small extracellular vesicles

INTRODUCTION

Human pregnancy requires acceptance and support for the semi-allogeneic embryo and effective protection of both mother and fetus. A failure to adapt, from either side, may cause abortion. The placenta-derived extracellular vesicles (EVs) have a crucial role in human implantation and pregnancy. These are lipid bilayer membrane-delimited, nano-to-micro sized extracellular microvesicles of endosomal origin, containing diverse signaling molecules, and functioning as short and long-distance messengers. We have already shown that first-trimester placenta releases the soluble HLA-C and HLA-G KIR ligands to modulate maternal cytotoxicity via the KIR/HLA axis. This study is to find whether extravillous trophoblast (EVT) secretes these HLA class I molecules via small EVs.

METHODS

sEVs were isolated by ultrafiltration or precipitation from serum-free conditioned media from primary trophoblast-derived EVT, and non-tumor EVT-like model Sw71 cell line, cultured as monolayer and spheroids. sEVs from cultured placental explants served as a positive control. Combined data from several methods was used for their characterization including BCA, DLS, TEM, IEM, Dot blot, and FACS.

RESULTS

Primary trophoblast-derived EVT and Sw71 EVT-like cells produced intact and well-visible CD63+, HLA-G- and HLA-C-bearing sEVs, regardless of culture mode and type of isolation. Both methods yielded sEVs sized 30-100 nm.

DISCUSSION

We show original data on the HLA-C secretion via sEVs by early pregnancy EVT and confirm the production of HLA-G-positive sEVs. A new asset to the usefulness of the Sw71 spheroid model as an implanting blastocyst surrogate is added as a tool to elucidate the sEV-based signalization in the implantation.

Platelet-derived extracellular vesicles: emerging players in hemostasis and thrombosis

Platelets, long recognized for their role in hemostasis and thrombosis, have emerged as key players in a wide array of physiological and pathological processes through the release of platelet-derived extracellular vesicles (PEVs). These nanoscale vesicles, rich in bioactive molecules such as proteins, lipids, and nucleic acids, facilitate intercellular communication and influence processes ranging from angiogenesis and inflammation to immune modulation and tissue repair. PEVs, the most abundant extracellular vesicles in circulation, display procoagulant activity 50-100 times greater than activated platelets, underscoring their pivotal role in hemostasis and thrombosis. Recent research has unveiled their dual role in health and disease, highlighting their potential as diagnostic biomarkers and therapeutic vehicles. PEVs are implicated in cancer progression, autoimmune diseases, and infectious diseases, where they modulate tumor microenvironments, immune responses, and inflammatory pathways. Moreover, their ability to deliver therapeutic agents with high specificity and biocompatibility positions them as promising tools in regenerative medicine, drug delivery, and targeted therapies. This review comprehensively explores PEV biogenesis, cargo composition, and their multifaceted roles in hemostasis and thrombosis, as well as their broader implications in disease. It also explores the potential of PEVs as diagnostic markers and innovative therapeutic strategies, offering insights into their application in treating thrombotic disorders, cancer, and inflammatory diseases. Despite significant advancements, challenges remain in standardizing isolation protocols and translating preclinical findings into clinical applications. Unlocking the full potential of PEVs promises to revolutionize diagnostics and therapeutics, paving the way for novel approaches to managing complex diseases.

A machine-learning approach for pancreatic neoplasia classification based on plasma extracellular vesicles

Introduction

Pancreatic cancer (PC) is a lethal disease developing from either exocrine or endocrine cells. Efforts to assist early diagnosis focus on liquid biopsy methods, and especially on the detection of Extracellular Vesicles (EVs) secreted from cancer cells in their microenvironment and accumulated in systemic circulation. Multiple studies explore how EVs size, surface biomarkers or content can determine their unique role and function in the recipient cell's gene expression, metabolism and behavior affecting cancer development. This study aimed to develop a machine learning-driven (ML) pipeline utilizing clinical variables and EV-based features to predict the presence of pancreatic tumors of different nature (exocrine/endocrine) in patients' plasma compared to patients with benign lesions or age-matched non-oncological patients.

Methods

All available plasma samples (N=126) and variables were collected prior to surgery. EVs were detected and characterized by flow cytometry-immunostaining. Data including size and a unique set of biomarkers (CD45, CD63 and EphA2) were combined with hematological/biochemical data and processed under two use cases, each formulated as a 3-class classification problem for patient risk stratification. The first use case aimed at classifying patients as with benign lesions or exocrine/endocrine neoplasms. The second use case aimed to distinguish patients with exocrine/endocrine neoplasms from non-oncological patients. Various ML methods were applied, including Logistic Regression, Random Forest, Support Vector Machines, and Extreme Gradient Boosting. Evaluation metrics, as area under the receiver operating characteristic curve (AUC-ROC), were computed, and Shapley values were utilized to determine features with the greatest impact on the discrimination of outcome groups.

Results

Analyses identified hematological and biochemical features, among significant predictors. Models demonstrated substantial accuracy and AUC-ROC values based on plasma EVs subpopulations, which scored over 0.90 in accuracy of the Random Forest and XGBoost algorithms, presenting 0.96 +/- 0.03 accuracy in the first use case and 0.93 +/- 0.04 in the second.

Discussion

By leveraging advanced analytical ML-driven approaches and integrating diverse data types, this study achieved significant accuracy, assisting patient's risk estimation and supporting the feasibility for early detection of pancreatic cancer. Going beyond currently used biomarkers such as CEA, or CA19.9, EV-based features represent an added value offering increased diagnostic capacity.

Advancing Leukemia Management Through Liquid Biopsy: Insights into Biomarkers and Clinical Utility

Liquid biopsy is classically defined as the detection of biomarkers in bodily fluids. One of these biomarkers can be circulating cell-free DNA (cfDNA) released by healthy or cancer cells during apoptosis. These fragments can be quantified and molecularly characterized by techniques like digital droplet PCR (ddPCR) or next-generation sequencing (NGS). By identifying common genetic and epigenetic alterations associated with specific cancer types, cfDNA or circulating tumor DNA (ctDNA) can serve as robust biomarkers for monitoring tumor initiation and progression. Other biomarkers, such as circulating microRNAs (miRNAs), extracellular vesicles, or circulating tumor cells (CTCs) are also applied in this context. Liquid biopsy has gained attention as a versatile tool for cancer diagnostics, prognosis, therapeutic monitoring, and minimal residual disease (MRD) detection across various malignancies, including hematological cancers like myeloid and lymphoid leukemias. Herein, we present a comprehensive review of liquid biopsy usage in leukemia, with a specific focus on the clinical utility of ctDNA, miRNAs, and exosomes in monitoring treatment response, tracking clonal evolution, and detecting minimal residual disease. Our review emphasizes the translational implications of these tools for improving patient outcomes and outlines current challenges in their integration into clinical practice.

Unlocking the Secrets of Human Milk: Isolation and Characterization of Extracellular Vesicles

Extracellular vesicles from human milk (HMEVs) are crucial for neonatal development, immune modulation, and protection against pathogens. However, the lack of standardized isolation and characterization protocols poses significant challenges. This review aims to evaluate and compare various methods for the isolation and characterization of HMEVs, highlighting their effectiveness and potential applications. Preliminary purification steps, including the removal of cells, fat globules, and casein micelles, enhance the purity of isolated HMEVs. We categorized isolation methods into density-based, size-based, and affinity-based techniques. Density-based methods include differential and density gradient ultracentrifugation. Size-based methods encompass polymer precipitation, membrane filtration, electrophoretic filtration, size exclusion chromatography, and microfluidics. Affinity-based methods involve immunoisolation using antibodies specific to HMEV surface proteins. Characterization techniques discussed include flow cytometry, dynamic light scattering, nanoparticle tracking analysis, tunable resistive pulse sensing, electron microscopy, atomic force microscopy, confocal microscopy, western blotting, ELISA, and lateral flow immunoassay systems. Differential ultracentrifugation, considered the "gold standard," provides high purity but is time-consuming. Density gradient ultracentrifugation offers precise separation. Size-based methods like polyethylene glycol precipitation and membrane filtration are simple and fast. Electrophoretic filtration and microfluidics provide precise control of sample flow. Affinity-based methods are highly specific but costly. Advanced characterization techniques provide comprehensive insights into HMEV properties and functions. Standardizing isolation protocols and employing advanced characterization techniques are essential for advancing HMEV research. Future studies should focus on understanding the molecular mechanisms of HMEVs, exploring the impact of maternal health, and developing targeted delivery technologies. These efforts will enhance the therapeutic potential of HMEVs in neonatal care and contribute to personalized nutritional interventions.

[Mechanism of extracellular vesicles in the repair of intervertebral disc degeneration]

Extracellular vesicles (EVs), defined as cell-secreted nanoscale vesicles that carry bioactive molecules, have emerged as a promising therapeutic strategy in tumor and tissue regeneration. Their potential in repairing intervertebral disc degeneration (IDD) through multidimensional regulatory mechanisms is a rapidly advancing field of research. This paper provided an overview of the mechanisms of EVs in IDD repair, thoroughly reviewed recent literature on EVs for IDD, domestically and internationally, and summarized their therapeutic mechanisms. In IDD repair, EVs could act through different mechanisms at the molecular, cellular, and tissue levels. At the molecular level, EVs could treat IDD by inhibiting inflammatory reactions, suppressing oxidative stress, and regulating the synthesis and decomposition of extracellular matrix. At the cellular level, EVs could treat IDD by inhibiting cellular pyroptosis, ferroptosis, and apoptosis and promoting cell proliferation and differentiation. At the tissue level, EVs could treat IDD by inhibiting neovascularization. EVs have a strong potential for clinical application in the treatment of IDD and deserve more profound study.

Comparison of in-vitro immunomodulatory capacity between large and small apoptotic bodies from human bone marrow mesenchymal stromal cells

BACKGROUND

Mesenchymal stromal cell (MSC) apoptosis is essential for their therapeutic effects, including immunomodulation. Previous studies have shown that MSC-derived apoptotic bodies (ApoBDs) also possess immunomodulatory properties. However, compared to small extracellular vesicles, the preparation, characterization, and biological properties of ApoBDs remain underexplored.

RESULTS

ApoBDs were isolated from the conditioned medium of staurosporine-induced apoptotic human MSCs and categorized into large (∼700 nm) and small (∼500 nm) groups. Both types expressed CD90, CD44, and CD73, with low levels of PD-L1, CD11b, and HLA-DR, mirroring their parental MSCs. Functional assays revealed that both ApoBDs inhibited allogeneic T-cell proliferation, with large ApoBDs demonstrating superior efficacy. In macrophage co-culture experiments, both ApoBDs polarized M1 macrophages toward an M2-like phenotype, with large ApoBDs more effectively upregulating CD163 expression. Additionally, both ApoBDs suppressed the proliferation of murine primary T cells. Furthermore, large ApoBDs exhibited enhanced macrophage uptake, as confirmed by flow cytometry and immunocytochemistry. Importantly, no cytotoxicity was observed for either ApoBD type following staurosporine treatment.

CONCLUSIONS

Staurosporine-induced ApoBDs are non-cytotoxic and exhibit significant immunomodulatory potential in vitro. Large ApoBDs are more effective than small ApoBDs in T-cell suppression and M2 macrophage polarization, suggesting their potential as an alternative to MSC-based therapies in future studies.

Extracellular membrane particles en route to the nucleus - exploring the VOR complex

Intercellular communication is an essential hallmark of multicellular organisms for their development and adult tissue homeostasis. Over the past two decades, attention has been focused on communication mechanisms based on various membrane structures, as illustrated by the burst of scientific literature in the field of extracellular vesicles (EVs). These lipid bilayer-bound nano- or microparticles, as vehicle-like devices, act as regulators in various biological and physiological processes. When EVs are internalized by recipient cells, their membrane and cytoplasmic cargoes can interfere with cellular activities, affecting pathways that regulate cell proliferation, differentiation, and migration. In cancer, EVs can transfer oncogenic factors, stimulate neo-angiogenesis and immunosuppression, reprogram stromal cells, and confer drug resistance traits, thereby remodeling the surrounding microenvironment. Although the mechanisms underlying EV biogenesis and uptake are now better understood, little is known about the spatiotemporal mechanism(s) of their actions after internalization. In this respect, we have shown that a fraction of endocytosed EVs reaches the nuclear compartment via the VOR (VAP-A-ORP3-Rab7) complex-mediated docking of late endosomes to the outer nuclear membrane in the nucleoplasmic reticulum, positioning and facilitating the transfer of EV cargoes into the nucleoplasm via nuclear pores. Here, we highlight the EV heterogeneity, the cellular pathways governing EV release and uptake by donor and recipient cells, respectively, and focus on a novel intracellular pathway leading to the nuclear transfer of EV cargoes. We will discuss how to intercept it, which could open up new avenues for clinical applications in which EVs and other small extracellular particles (e.g., retroviruses) are implicated.

Mesenchymal stem cells and their extracellular vesicles: new therapies for cartilage repair

Cartilage is crucial for joints, and its damage can lead to pain and functional impairment, causing financial burden to patients. Due to its weak self-repair, cartilage injury control is a research focus. Cartilage injury naturally with age, but mechanical trauma, lifestyle factors and certain genetic abnormalities can increase the likelihood of symptomatic disease progression. Current treatments for cartilage injury include pharmacological and surgical interventions, but these lack the ability to stop the progression of disease and restore the regeneration of the cartilage. Biological therapies have been evaluated but show varying degrees of efficacy in cartilage regeneration long-term. The mesenchymal stem cell (MSC) therapy attracts attention as it is easily harvested and expanded. Once thought to repair via differentiation, MSCs are now known to secrete extracellular vesicles (EVs) paracrinely. These EVs, rich in bioactive molecules, enable cell communication, boost growth factor secretion, regulate the synthesis and degradation of extracellular matrix (ECM), and modulate inflammation, vital for cartilage repair. However, further research and clinical validation are still required for the application of MSC and MSC-EVs. This review highlights the current state of research on the use of MSC and MSC-EVs in the treatment of cartilage injury. It is hoped that the review in this paper will provide valuable references and inspiration for future researchers in therapeutic studies of cartilage repair.

Continuous collection of human mesenchymal-stromal-cell-derived extracellular vesicles from a stirred tank reactor operated under xenogeneic-free conditions for therapeutic applications

BACKGROUND

Mesenchymal-stromal-cell-derived extracellular vesicles (MSC-EVs) play a key role in the paracrine effects of MSC and have demonstrated therapeutic potential in various preclinical models. However, clinical translation is hindered by manufacturing practices relying on planar culture systems, fetal bovine serum (FBS)-supplemented media, and non-scalable, low-purity EV isolation methods that fail to meet dose and safety requirements, underscoring the need for innovative approaches. In this study, we developed a scalable platform to manufacture human MSC-EVs at clinically relevant numbers, integrating continuous collection of EV-enriched conditioned media (CM) using a stirred-tank reactor (STR) under xenogeneic-free conditions and a scalable downstream process.

METHODS

Wharton's jelly-derived MSC (MSC(WJ)) were expanded using microcarriers in a controlled STR using human platelet lysate (hPL)-supplemented medium. Then, a 3-day EV production stage, featuring continuous harvesting of the CM, was established using a novel serum-/xeno(geneic)-free exosome depleted-hPL supplement. For the isolation of MSC-EVs, a scalable process was implemented by pairing tangential flow filtration and anion exchange chromatography. Isolated MSC-EVs were characterised using nanoparticle tracking analysis, protein and zeta potential quantification, western blot analysis of EV protein markers, transmission electron microscopy and uptake studies of fluorescently labelled-EVs.

RESULTS

The system sustained the efficient expansion of MSC(WJ), reaching a total of (6.03 ± 0.181) x 107 cells after 7 days, which corresponds to a 30.1 ± 0.740-fold expansion. Upon a 3-day continuous CM harvesting, a total of (2.13 ± 0.301) x 1012 EVs were isolated corresponding to a particle yield factor of (1.26 ± 0.186) x 104 EVs/cell/day. MSC-EVs presented high purity levels ((5.53 ± 1.55) x 109 particles/µg), a homogeneous small size distribution (mean diameter of 115 ± 4.88 nm), a surface charge of -23.4 ± 6.23 mV, positive detection of tetraspanins CD9 and CD63 and syntenin-1 and displayed a typical cup-shaped morphology. MSC-EVs were readily incorporated by endothelial cells and two human breast cancer cell lines.

CONCLUSIONS

Overall, the scalable and Good Manufacturing Practices (GMP)-compliant platform established herein enabled the reproducible manufacturing of MSC-EVs with high purity and generally accepted characteristics concerning size, protein markers, surface charge, morphology, and cellular internalization, validating its potential for future clinical applications.

Lactiplantibacillus plantarum -derived extracellular vesicles alleviate acute lung injury by inhibiting ferroptosis of macrophages

Despite considerable advancements in understanding the mechanisms of ALI, the therapeutic options available in clinical practice remain predominantly supportive, highlighting the urgent need for innovative treatments. In this study, we investigated the potential protective benefits of extracellular vehicles from the probiotic strain Lactiplantibacillus plantarum (LpEVs) in ALI mouse model. We revealed that LpEVs administration attenuated LPS-induced ALI, as evidenced by reduced lung pathology, decreased inflammatory markers, and mitigated ferroptosis. In vitro experiments demonstrated that LpEVs restrained ferroptosis and promoted a shift towards an anti-inflammatory macrophage phenotype. Moreover, LpEVs increased the expression of NRF2, resulting in the promotion of HO1 and strengthening anti-ferroptotic System Xc-/GPX4 axis. Our analysis revealed that LpEVs alleviated ALI through the suppression of macrophages ferroptosis by delivering cbn-let-7 targeting ferroptosis-related gene Acsl4. These findings propose LpEVs as a promising therapeutic approach for preventing and treating ALI, highlighting the potential of leveraging probiotic-derived biomolecules to develop novel therapeutic strategies.

Force spectroscopy reveals membrane fluctuations and surface adhesion of extracellular nanovesicles impact their elastic behavior

The elastic properties of nanoscale extracellular vesicles (EVs) are believed to influence their cellular interactions, thus having a profound implication in intercellular communication. However, accurate quantification of their elastic modulus is challenging due to their nanoscale dimensions and their fluid-like lipid bilayer. We show that the previous attempts to develop atomic force microscopy-based protocol are flawed as they lack theoretical underpinning as well as ignore important contributions arising from the surface adhesion forces and membrane fluctuations. We develop a protocol comprising a theoretical framework, experimental technique, and statistical approach to accurately quantify the bending and elastic modulus of EVs. The method reveals that membrane fluctuations play a dominant role even for a single EV. The method is then applied to EVs derived from human embryonic kidney cells and their genetically engineered classes altering the tetraspanin expression. The data show a large spread; the area modulus is in the range of 4 to 19 mN/m and the bending modulus is in the range of 15 to 33 [Formula: see text], respectively. Surprisingly, data for a single EV, revealed by repeated measurements, also show a spread that is attributed to their compositionally heterogeneous fluid membrane and thermal effects. Our protocol uncovers the influence of membrane protein alterations on the elastic modulus of EVs.

Proteomic signatures of retinal pigment epithelium-derived exosomes in myopic and non-myopic tree shrew eyes

Purpose

The retinal pigment epithelium (RPE) transmits growth signals from the neural retina to the choroid in the emmetropization pathway, but the underlying molecular mechanisms remain poorly understood. Here, we compared the proteomic profiles of RPE-derived exosomes between myopic and non-myopic eyes of tree shrews, dichromatic mammals closely related to primates.

Methods

Four myopic (159-210 days of visual experience, DVE) and seven non-myopic eyes (156-210 DVE) of tree shrews were included. Non-cycloplegic refractive error was measured with Nidek autorefractor, and axial ocular component dimensions were recorded with LenStar. Tissue was collected, yielding RPE-lined eyecups, which were subsequently incubated in L-15 culture media for 2 h. The RPE-derived exosomes were then enriched and purified from the incubation media by double ultracentrifugation and characterized by imaging and molecular methods. Exosomal proteins were identified and quantified with mass spectrometry, examined using GO and KEGG analyses, and compared between myopic and non-myopic samples.

Results

Out of 506 RPE exosomal proteins identified, 48 and 41 were unique to the myopic and non-myopic samples, respectively. There were 286 differentially expressed proteins in the myopic samples, including 79 upregulated and 70 downregulated. The top three upregulated proteins were Histone H4 (Fold Change, FC = 3.04, p = 0.09), PTB 1 (FC = 2.59, p = 0.08) and Histone H3.1 (FC = 2.59, p = 0.13), while the top three downregulated proteins were RPS5 (FC = -2.41, p=0.004), ACOT7 (FC=-2.15, p = 0.04) and CRYBB2 (FC = -2.14, p = 0.05). Other differentially expressed proteins included LUM, VCL, SEPTIN11, GPX3, SPTBN1, SEPTIN7, RPL10A, KCTD12, FGG, and FMOD. Proteomic analysis revealed a low abundance of ATP6V1B2 and crystallin beta B2, and a significant depletion of the crystallin protein family (crystallin A2, A3, and B3 subunits) in the myopic samples. The enrichment analyses showed extracellular matrix, cytoskeletal dynamic, and cell-matrix adhesion as the primary components associated with the RPE exosomal proteins in myopic eyes.

Conclusion

Using standard molecular and imaging techniques, this study provides the first demonstration of the ex-vivo RPE exosome biogenesis from tree shrew eyes. The results showed distinct differential expressions of the RPE exosomal proteins between the myopic and non-myopic eyes, with several proteins unique to each group. Future targeted proteomic studies of identified candidate exosomal protein signatures could elucidate the molecular mechanism of RPE exosome-mediated growth signal transmission in the emmetropization pathway.

Exosomes in Systemic Autoimmune Diseases: Recent Advances in Diagnostic Biomarkers and Therapeutic Applications

Systemic autoimmune diseases (SADs) encompass a spectrum of organ involvement, clinical heterogeneity, and therapeutic challenges meriting significant research. These conditions involve the immune system mistakenly attacking and damaging multiple body tissues and organs, leading to chronic inflammation and damage. Exosomes are nanoscale extracellular vesicles secreted by cells that modulate intercellular communication and immunity. Accumulating evidence indicates that exosomes have multifaceted roles in the pathogenesis of SADs through processes like cellular signaling, immune modulation, antigen presentation, and inflammatory response. The cargo of exosomes, such as proteins, miRNAs, and lipids, are vital determinants of cellular and humoral immunity. This review examines key signaling pathways in four common SADs, rheumatoid arthritis, systemic lupus erythematosus, systemic sclerosis, and Sjögren's syndrome, and explores exosome as non-invasive biomarkers for diagnosis, disease monitoring, and therapeutic response prediction. Additionally, the therapeutic potential of mesenchymal stromal cells (MSCs) or various type of mesenchymal stem cells derived exosomes as cell-free immunotherapies for SADs is highlighted. Engineered exosomes, with enhanced targeting, bioavailability, low toxicity, are emerging as promising drug delivery vehicles. However, challenges such as high production costs, technical complexity, and inefficiency, along with the lack of standardized protocols, limit clinical implementation in SADs. A deeper understanding of exosome roles in SADs pathogenesis and innovative immunotherapies may provide valuable theoretical support for the diagnosis and treatment of these challenging conditions.

Decoding Complex Biological Milieus: SHINER's Approach to Profiling and Functioning of Extracellular Vesicle Subpopulations

Extracellular vesicles (EVs) are celebrated for their pivotal roles in cellular communication and their potential in disease diagnosis and therapeutic applications. However, their inherent heterogeneity acts as a double-edged sword, complicating the isolation of specific EV subpopulations. Conventional EV isolation methods often fall short, relying on biophysical properties, while affinity-based techniques may compromise EV integrity and utility with harsh recovery conditions. To address these limitations, the SHINER (subpopulation homogeneous isolation and nondestructive EV release) workflow is introduced, which redefines how EVs are isolated and recoverd, featuring the innovative SWITCHER (switchable extracellular vesicle releaser) tool. The SHINER workflow facilitates the precise purification and gentle recovery of target EV subpopulations from complex biological mixtures, preserving their structural integrity and biological functionality. Importantly, SHINER demonstrates exceptional adaptability to multiple markers and clinical applications. It not only enhances the ability to trace EV origins for accurate disease diagnosis but also advances fundamental EV research and provides standardized EV materials for therapeutic innovations. By improving the understanding of EVs and enabling the development of personalized diagnostics and treatments, SHINER propels EV-based science into new frontiers of advanced medicine, offering transformative potential for healthcare.

Preserving Blood-Brain Barrier Integrity in Ischemic Stroke: a Review on MSCs-sEVs Content and Potential Molecular Targets

Ischemic stroke (IS) is a life-threatening condition that constitutes the second leading cause of death globally. Despite its high impact on public health, there is a shortage of treatments due to the complexity of the cellular and molecular mechanisms implicated. One main limiting factor for successful IS therapeutic intervention is stroke-induced blood-brain barrier (BBB) damage, particularly over tight junction proteins (TJs). BBB disruption is a well-established feature of IS, accelerating ischemic tissue damage and worsening prognosis. In recent years, mesenchymal stem cells (MSCs) and their small extracellular vesicles (MSCs-sEVs) have emerged as promising therapeutic interventions for several neurological disorders, including IS. However, its effects on BBB repair after IS are not completely understood. In this review, we will discuss novel experimental evidence of MSCs-sEVs effects in BBB protection and highlight the relevance of molecules reported in MSCs-sEVs, their potential cellular and molecular targets, and putative mechanisms implicated in BBB repair, providing a promising research avenue that may translate into effective therapeutic strategies for IS.

Morphological characteristics, extracellular vesicle structure and stem-like specificity of human follicular fluid cell subpopulation during osteodifferentiation

Extracellular vesicles can play an important role in the processes occurring after stem cell transplantation, preventing cell apoptosis, stimulating immunological processes, and promoting the synthesis of extracellular matrix. Human follicular fluid (FF) can be a source of a subpopulation of cells with mesenchymal stem cells (MSCs) properties. Moreover these subpopulations of FF cells can differentiate into osteoblasts. In presented studies flow cytometry of ovarian FF cells confirmed positive expression of MSCs markers such as: CD44, CD90, CD105, CD73 and negative expression of a hematopoietic marker: CD45. The CD90+, CD105+, CD45- cell subpopulation has been obtained during magnetic separation using appropriate antibodies conjugated with microbeads. The extracellular vesicles (EVs) secreted by the cells during osteodifferentiation process differed from those secreted by cells culture in the basal medium. Based on the previous and current electron microscopy research, changes in size, number, and shape would support the notion that released EVs could be crucial to the ovarian FF cell subpopulation differentiation process. Osteogenic differentiation has been confirmed via Alizarin red staining. Therefore, follicular fluid (FF) can be a new source of a cell subpopulation with MSC properties, with the cells capable of differentiating into the osteogenic lineage. EVs could play a key role as mediators in tissue regeneration, especially bone tissue regeneration.

Cutting-Edge Progress in the Acquisition, Modification and Therapeutic Applications of Exosomes for Drug Delivery

Exosomes are vesicles secreted by cells, typically ranging from 30 to 150 nm in diameter, and serve as crucial mediators of intercellular communication. Exosomes are capable of loading various therapeutic substances, such as small molecule compounds, proteins, and oligonucleotides, thereby making them an ideal vehicle for drug delivery. The distinctive biocompatibility, high stability, and targeting properties of exosomes render them highly valuable for future treatments of diseases like cancer and cardiovascular diseases. Despite the potential advantage of exosomes in delivering biologically active molecules, the techniques for the preparation, purification, preservation, and other aspects of stem cell exosomes are not yet mature enough. In this paper, we briefly introduce the composition, biogenesis, and benefits of exosomes, and primarily focus on summarizing the isolation and purification methods of exosomes, the preparation of engineered exosomes, and their clinical applications, to better provide new ideas for the development of exosome drug delivery systems.

Extracellular Vesicles and Their Role in Skin Inflammatory Diseases: From Pathogenesis to Therapy

Extracellular vesicles (EVs), including exosomes, microvesicles, and apoptotic bodies, are released into the extracellular space by almost all known cell types. They facilitate communication between cells by transferring bioactive molecules, which impact both physiological processes and the development of diseases. EVs play a crucial role in the pathogenesis of various diseases by participating in multiple pathological processes. They contribute to disease progression by triggering cytokine release, modulating immune cell activity, and inducing inflammatory and immune responses. Beyond their pathological implications, EVs also offer significant therapeutic potential. Both natural and engineered EVs show great potential in the fields of targeted therapy, drug delivery, and immune modulation in dermatological applications. The development of EV-based treatments is showing promise in advancing patient outcomes, particularly in chronic inflammatory and immune-mediated skin conditions. This review comprehensively examined the biogenesis, classification, and functional roles of EVs, including advanced methods for their isolation and characterization. Furthermore, we summarized recent studies highlighting the involvement of EVs in four major inflammatory skin diseases: psoriasis, atopic dermatitis, systemic lupus erythematosus, and wound healing.

The Immunomodulatory mechanism and research progress of mesenchymal stem cells in the treatment of allergic rhinitis

BACKGROUND

Allergic rhinitis (AR) affects 10-40% of the global population, yet current therapies (drugs, immunotherapy) face limitations in efficacy and safety. Mesenchymal stem cells (MSCs) have emerged as a promising alternative due to their immunomodulatory properties.

KEY FINDINGS

Preclinical studies demonstrate that MSCs from adipose, bone marrow, umbilical cord, and tonsils reduce AR symptoms (sneezing, nasal inflammation) and serum IgE (Immunoglobulin E) levels by restoring Th1/Th2 immune equilibrium and enhancing Treg (Regulatory T cells) activity. MSC-derived exosomes and hydrogel-encapsulated formulations further improve targeting and safety. However, clinical translation is hindered by heterogeneous protocols and unresolved long-term risks (e.g., tumorigenicity).

CLINICAL SIGNIFICANCE

MSC-based therapies offer potential for durable AR remission by addressing immune dysregulation at its root. Future efforts must prioritize standardized production, phase I safety trials, and combination strategies (e.g., exosomes + hydrogels) to accelerate clinical adoption.

Neuronally Derived Extracellular Vesicles' Oligomeric and p129-α-Synuclein Levels for Differentiation of Parkinson's Disease from Essential Tremor

Clinical differentiation between Parkinson's disease (PD) and essential tremor (ET) may be challenging, highlighting the need for easily assessable diagnostic biomarkers. Neuronally derived extracellular vesicles (NDEVs) have been proposed as a peripheral matrix that can well recapitulate the cellular composition of neurons. We investigated the clinical usefulness of NDEV oligomeric and p129-α-synuclein levels in discriminating between patients with PD and those with ET. NDEV oligomeric and p129-α-synuclein species were assessed using an ELISA in 43 patients with PD, 21 patients with ET, and 45 healthy controls (HCs). NDEV oligomeric α-synuclein levels were significantly higher in PD in comparison with ET and HCs, while p129-α-synuclein values were significantly lower in HCs compared to other groups. By using a receiver operator characteristic (ROC) analysis, oligomeric-α-synuclein achieved an excellent classification performance in distinguishing PD from both ET and HCs (AUC: 0.976 and 0.997, respectively), while lower performance was obtained in differentiating ET from HCs (AUC: 0.85). On the other hand, p129-α-synuclein accurately discriminated both PD and ET from HCs (AUC: 0.997 and 0.952, respectively) but had very low performance in differentiating PD from ET (AUC: 0.47). Our study suggests that NDEV oligomeric α-synuclein is an accurate blood-derived biomarker to differentiate PD from ET, while p129-α-synuclein may be useful in distinguishing ET from HCs.

Harnessing stem cell-derived exosomes: a promising cell-free approach for spinal cord injury

Spinal cord injury (SCI) is a severe injury to the central nervous system that often results in permanent neurological dysfunction. Current treatments have limited efficacy and face challenges in restoring neurological function after injury. Recently, stem cell-derived exosomes have gained attention as an experimental treatment for SCI due to their unique properties, including superior biocompatibility, minimal immunogenicity and non-tumorigenicity. With their potential as a cell-free therapy, exosomes promote SCI repair by enhancing nerve regeneration, reducing inflammation and stabilizing the blood-spinal cord barrier. This review summarizes advances in stem cell-derived exosome research for SCI over the past years, focusing on their mechanisms and future prospects. Despite their promising therapeutic potential, clinical translation remains challenging due to standardization of exosome isolation protocols, compositional consistency and long-term safety profiles that require further investigation.

Advances in the biochemical diagnostics of primary aldosteronism: from immunoassays to steroidomics and proteomics

Primary aldosteronism is the most common cause of secondary hypertension, yet most cases remain unrecognized and left without optimal treatment. The diagnostic inertia may be attributed to the lack of specific symptoms, insufficient awareness among physicians, still conflicting indications for screening for primary aldosteronism and first and foremost challenging diagnostics. This review describes the current challenges of biochemical diagnostics of primary aldosteronism, including screening, case confirmation and subtyping. It also discusses immunoassays widely used in assessment of suspected autonomous aldosterone secretion - recent advances in the field and limitations of the method in comparison to the gold standard - liquid chromatography -tandem mass spectrometry. The review focuses on the application of novel "omics" strategies in the diagnostics of primary aldosteronism. Steroidomics and proteomics offer a possibility to simultaneously assess steroids and protein/peptides on a large scale. This multianalyte approach in comparison to the selective quantification of a chosen compound has been proved useful in the diagnostics of primary aldosteronism. It also offers a unique insight into the individual characteristics, underlying mechanisms and even reflects the genetic alterations of primary aldosteronism cases. The "omics" techniques are associated with large amounts of generated data, the interpretation of which may be troublesome and often necessitates the use of artificial intelligence. The novel advances in the biochemical diagnostics of primary aldosteronism, including "omics" techniques, presented in this review may help to address the most emerging problems, increase the number of diagnosed patients and facilitate the choice of an optimal treatment.

Neural stem cell-derived small extracellular vesicles: a new therapy approach in neurological diseases

Neural stem cells (NSCs) possess pluripotent characteristics, proliferative capacity, and the ability to self-renew. In the context of neurological diseases, transplantation of NSCs has been shown to facilitate neurological repair through paracrine mechanisms. NSC-derived small extracellular vesicles (NSC-sEVs), a prominent component of the NSC secretome, play a crucial role in modulating various physiological and pathological processes, such as regulating the NSC microenvironment, promoting endogenous NSC differentiation, and facilitating the maturation of neurons and glial cells. Moreover, NSC-sEVs exhibit reduced immunogenicity, decreased tumorigenic potential, and enhanced ability to traverse the blood-brain barrier. Consequently, NSC-sEVs present novel therapeutic approaches as non-cellular treatments for neurological disorders and are poised to serve as a viable alternative to stem cell therapies. Furthermore, NSC-sEVs can be manipulated to enhance production efficiency, improve biological activity, and optimize targeting specificity, thereby significantly advancing the utilization of NSC-sEVs in clinical settings for neurological conditions. This review provides a comprehensive overview of the biological functions of NSC-sEVs, their therapeutic implications and underlying molecular mechanisms in diverse neurological disorders, as well as the potential for engineering NSC-sEVs as drug delivery platforms. Additionally, the limitations and challenges faced by NSC-sEVs in practical applications were discussed in depth, and targeted solutions were proposed.