Isolation and characterization of extracellular vesicles from Broncho-alveolar lavage fluid: a review and comparison of different methods

Extracellular vesicles: translational research and applications in neurology

Over the past few decades, extensive basic, translational and clinical research has been devoted to deciphering the physiological and pathogenic roles of extracellular vesicles (EVs) in the nervous system. The presence of brain cell-derived EVs in the blood, carrying diverse cargoes, has enabled the development of predictive, diagnostic, prognostic, disease-monitoring and treatment-response biomarkers for various neurological disorders. In this Review, we consider how EV biomarkers can bring us closer to understanding the complex pathogenesis of neurological disorders such as Alzheimer disease, Parkinson disease, stroke, traumatic brain injury, amyotrophic lateral sclerosis and multiple sclerosis. We describe how translational research on EVs might unfold bidirectionally, proceeding from basic to clinical studies but also in the opposite direction, with biomarker findings in the clinic leading to novel hypotheses that can be tested in the laboratory. We demonstrate the potential value of EVs across all stages of the therapeutic development pipeline, from identifying therapeutic targets to the use of EVs as reporters in model systems and biomarkers in clinical research. Finally, we discuss how the cargo and physicochemical properties of naturally occurring and custom-engineered EVs can be leveraged as novel treatments and vehicles for drug delivery, potentially revolutionizing neurotherapeutics.

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.

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.

Development of a Microfluidic System for Mitochondrial Extraction, Purification, and Analysis

Mitochondria, as essential cellular organelles, play a key role in numerous diseases, from neurodegenerative disorders to cancer and rare conditions. The extraction of mitochondria from cells has many applications in disease diagnosis, pathological research, and emerging mitochondrial transplantation therapy (MTT). Recent advancements in microfluidic-on-chip systems offer promising improvements in mitochondrial extraction by enabling high-throughput processing, precise control, and flexibility while facilitating integration with other devices and platforms. Despite growing interest in microfluidic mitochondrial extraction (MME), there is a lack of comprehensive reviews on the latest developments in this field. This review aims to summarize recent advancements as well as the advantages and limitations of MME, providing deeper insights into microfluidic-based approaches for mitochondrial extraction, purification, and analysis.

Elucidation of extracellular vesicles behavior during capillary isoelectric focusing

In this study, we investigated the behavior of extracellular vesicles (EVs), during capillary isoelectric focusing (cIEF). For that, we used different approaches, imaging cIEF with a whole-column imaging detection (WCID) and conventional cIEF as well as different detection methods (LIF after EV labelling, native fluorescence and UV). Our study reveals that EVs exhibit significant aggregation during their migration toward, and upon reaching, their isoelectric point (pI). By optimizing key parameters such as voltage and the addition of solubilizers, we successfully reduced this issue, particularly with bovine milk EVs. Our findings also showed distinct pI regions observed for EVs isolated from different sources: bovine milk EVs shows acidic pI characteristics (4.0-4.1), while pig and human plasma EVs exhibit more basic pI zones (4.7-4.9 and 5.8-6.7, respectively). The study was extended to cIEF coupled to laser induced fluorescence detection (LIF) using intra-vesicular CFDA-labeled EVs, to better understand their susceptibilities. Prolonged mobilization time due to long capillary lengths adversely affected EV's integrity in conventional cIEF. Our study reveals the necessity to specific cIEF optimization for each EV source due to variations in charge distribution and aggregation behavior across different pI regions. The use of a short capillary length (<10 cm), low electric field and solubilizers such as Tween-20 is recommended to preserve EVs integrity during cIEF-EV studies.

Intranasal delivery of extracellular vesicles: A promising new approach for treating neurological and respiratory disorders

BACKGROUND

Extracellular vesicles (EVs) are membrane vesicles secreted by all types of cells, including bacteria, animals, and plants. These vesicles contain proteins, nucleic acids, and lipids from their parent cells and can transfer these components between cells. EVs have attracted attention for their potential use in diagnosis and therapy due to their natural properties, such as low immunogenicity, high biocompatibility, and ability to cross the blood-brain barrier. They can also be engineered to carry therapeutic molecules. EVs can be delivered via various routes. The intranasal route is particularly advantageous for delivering them to the central nervous system, making it a promising approach for treating neurological disorders.

SCOPE OF REVIEW

This review delves into the promising potential of intranasally administered EVs-based therapies for various medical conditions, with a particular focus on those affecting the brain and central nervous system. Additionally, the potential use of these therapies for pulmonary conditions, cancer, and allergies is examined, offering a hopeful outlook for the future of medical treatments.

MAJOR CONCLUSIONS

The intranasal administration of EVs offers significant advantages over other delivery methods. By directly delivering EVs to the brain, specifically targeting areas that have been injured, this administration proves to be highly efficient and effective, providing reassurance about the progress in medical treatments. Intranasal delivery is not limited to brain-related conditions. It can also benefit other organs like the lungs and stimulate a mucosal immune response against various pathogens due to the highly vascularized nature of the nasal cavity and airways. Moreover, it has the added benefit of minimizing toxicity to non-targeted organs and allows the EVs to remain longer in the body. As a result, there is a growing emphasis on conducting clinical trials for intranasal administration of EVs, particularly in treating respiratory tract pathologies such as coronavirus disease.

Prospect of extracellular vesicles in tumor immunotherapy

Extracellular vesicles (EVs), as cell-derived small vesicles, facilitate intercellular communication within the tumor microenvironment (TME) by transporting biomolecules. EVs from different sources have varied contents, demonstrating differentiated functions that can either promote or inhibit cancer progression. Thus, regulating the formation, secretion, and intake of EVs becomes a new strategy for cancer intervention. Advancements in EV isolation techniques have spurred interest in EV-based therapies, particularly for tumor immunotherapy. This review explores the multifaceted functions of EVs from various sources in tumor immunotherapy, highlighting their potential in cancer vaccines and adoptive cell therapy. Furthermore, we explore the potential of EVs as nanoparticle delivery systems in tumor immunotherapy. Finally, we discuss the current state of EVs in clinical settings and future directions, aiming to provide crucial information to advance the development and clinical application of EVs for cancer treatment.

Comparison of nanoLC-MALDI-MS/MS with nanoLC-TIMS-MS/MS in the proteomic analysis of extracellular vesicles of bronchoalveolar lavage fluid

The study aims to evaluate and compare two advanced proteomic techniques, nanoLC-MALDI-MS/MS and nanoLC-TIMS-MS/MS, in characterizing extracellular vesicles (EVs) from the bronchoalveolar lavage fluid (BALF) of patients with asthma and idiopathic pulmonary fibrosis (IPF). Pulmonary diseases, driven by pollutants and infections, often necessitate detailed analysis of BALF to identify diagnostic biomarkers and therapeutic targets. EVs, which include exosomes, microvesicles, and apoptotic bodies, are isolated using filtration and ultracentrifugation, and their morphology, concentration, and size distribution are assessed through transmission electron microscopy (TEM) and nanoparticle tracking analysis (NTA). The proteomic profiles of these EVs are then analyzed using the aforementioned techniques, highlighting their unique and common proteins. The study found that nanoLC-TIMS-MS/MS identified significantly more proteins compared to nanoLC-MALDI-MS/MS. Functional analysis via Gene Ontology revealed pathways related to inflammation and cell signaling, underscoring the role of EVs in disease pathophysiology. The findings suggest that EVs in BALF can serve as valuable biomarkers and therapeutic targets in respiratory diseases, providing a foundation for future research and clinical applications.

Identifying the function of novel cross-species microRNAs from the excretory-secretory products of Angiostrongylus cantonensis fifth-stage larvae

BACKGROUND

Angiostrongylus cantonensis is a significant foodborne zoonotic parasite that causes severe neuropathological damage and symptoms in humans. Excretory-secretory products (ESPs) play a pivotal role in elucidating host-parasite interactions and can aid in penetrating host defensive barriers in helminths. Recently, secreted microRNAs have become important research targets for parasite-host communication. In this study, we determined the expression and function of novel microRNAs from A. cantonensis L5 ESPs and evaluated the effect of target microRNAs on the molecular mechanisms of mouse astrocytes.

METHODS

Here, we employed next-generation sequencing (NGS) to establish the secreted microRNAs dataset. Next, we evaluated the effects of AcESPs-microRNAs in A. cantonensis ESPs treated astrocytes.

RESULTS

First, we established the secreted microRNA dataset, and then comprehensively verified the characteristics. Novel microRNAs were initially detected, and their expression was found. Moreover, the prediction results showed that these secreted microRNAs may regulate Wnt and mTOR signaling. Next, the data showed that the AcNOVEL55 microRNA reduced cell apoptosis generation via regulating the RhoA-Rock signaling pathway in A. cantonensis L5 ESPs treated mouse astrocytes. Moreover, we also demonstrated that the AcNOVEL31 microRNA can affect the inflammation activation via regulating the presenilin-1/GSK3B/β-catenin/NF-κB pathway. Finally, the concentrations of secreted IL-6 and IL-12 proteins were downregulated by AcNOVEL31 microRNA by influencing presenilin-1 expression.

CONCLUSION

This is the first study to verify the molecular functions of novel microRNAs secreted by A. cantonensis. The discovery of the microRNA mechanisms by which cross-species parasitic nematodes influence hosts has advanced research on host-parasitic nematode interactions.

Respiratory extracellular vesicle isolation optimization through proteomic profiling of equine samples and identification of candidates for cell-of-origin studies

Growing evidence supports the importance of extracellular vesicle (EV) as mediators of communication in pathological processes, including those underlying respiratory disease. However, establishing methods for isolating and characterizing EVs remains challenging, particularly for respiratory samples. This study set out to address this challenge by comparing different EV isolation methods and evaluating their impacts on EV yield, markers of purity, and proteomic signatures, utilizing equine/horse bronchoalveolar lavage samples. Horses can serve as effective translational animal models for respiratory studies due to similarities with human immune responses, shared environmental exposures, and naturally occurring respiratory diseases including asthma. Further, horses are long-lived large animals that allow for longitudinal sample collection, and provide large sample volume and cell yield, which are particularly useful since EV research is commonly limited by low sample yields. Here, EVs were isolated from horse bronchoalveolar lavage fluid (BALF) using four different methods (ultracentrifugation, microcentrifugation, and two sizes of size exclusion chromatography columns) and characterized by measuring particle counts, EV purity, total protein yield, and proteomic cargo, with a specific focus on vesicle surface marker expression potentially informing cell type of origin. We found that size exclusion chromatography yielded the highest particle counts, greatest EV purity markers and elevated vesicle surface marker expression. Overall proteomic profiles differed across isolation methods, with size exclusion chromatography clustering separately from centrifugation. Taken together, our results demonstrate that different isolation methods impact characteristics of EVs, notably that size exclusion chromatography, compared to centrifugation methods, resulted in higher EV purity and better characterized proteomic diversity, including information on EV cell-of-origin. This is the first study to characterize proteomic profiles of EVs following different isolation methods using equine BALF. The results of this study will pave the way for future studies using equine and human samples to characterize respiratory tract EVs.

Isolation, Characterization, and Proteomic Analysis of Crude and Purified Extracellular Vesicles Extracted from Fusarium oxysporum f. sp. cubense

Extracellular vesicles (EVs) produced by Fusarium oxysporum f. sp. cubense (Foc) play vital roles in plant-pathogen interactions; however, the isolation of purified Foc TR4-EVs and their pathogenicity and proteomic profiles are not well studied. This study aims to isolate and characterize purified Foc TR4-EVs and compare their pathogenic effects and protein profiles with crude TR4-EVs. Foc TR4-EVs were isolated using ultracentrifugation and purified by iodixanol gradient centrifugation. After characterization and evaluation of the pathogenicity effects on banana leaves, LC-MS/MS was performed to conduct the proteomics assay. Results indicated that Fraction 2 EVs exhibited clearer spherical structures (TEM), excessive abundance (1.70 × 109 particles/mL), greater intensity (400 a.u), mean size (154.5 nm), moderate protein content (333.16 ng/µL), and protein profile (25-77 kDa), which were superior to Fractions 1, 3, and crude EVs. Crude EVs displayed significant background interference with EV structures (TEM), highest abundance (2.11 × 109 particles/mL), lower intensity (7.0 a.u), higher protein content (528.33 ng/µL), and higher molecular weight proteins (55-70 kDa) compared to gradient EVs. A non-significant biocontrol effect of Foc-EVs on the growth of TR4 spores was observed. Pathogenicity assays revealed that crude EVs caused the largest (2.805 cm2), while Fraction 2 (1.386 cm2) and Fraction 3 (1.255 cm2) resulted in moderate lesions on banana leaves. Proteomic analysis identified 807 unique proteins in Fraction 2, enriched in pathways related to EV trafficking and signaling. In comparison, crude EVs contained 179 unique non-EV proteins related to metabolism and secondary metabolites, indicating that non-EV proteins of crude EVs also influence the pathogenicity observed in banana leaves. This study emphasizes the importance of EV purification, with Fraction 2 being a critical focus for future research on Foc EV pathogenicity.

Extracellular vesicles in liquid biopsies: there is hope for oral squamous cell carcinoma

Current approaches to oral cancer diagnosis primarily involve physical examination, tissue biopsy, and advanced computer-aided imaging techniques. However, despite these advances, patient survival rates have not significantly improved. Hence, there is a critical need to develop minimally invasive tools with high sensitivity and specificity to improve patient survival and quality of life. Liquid biopsy is a non-invasive, real-time method for predicting cancer status and potentially serves as a biomarker source for treatment response. Liquid biopsy includes rich biologically relevant components, such as circulating tumor cells, circulating tumor DNA, and extracellular vesicles (EVs). EVs are particularly intriguing due to their relatively high abundance in most biofluids, with the potential to identify specific cargo derived from circulating tumor EVs. Moreover, normal cells in lymph nodes can uptake EVs, fostering a pre-metastatic microenvironment that facilitates lymph node metastases - a common occurrence in oral cancers. This review encompasses English language publications over the last twenty years, focusing on methods for isolating EVs from saliva, blood, and lymphatic fluids, as well as the collection methods employed. Seventeen cases met the inclusion criteria according to ISEV guidelines, including 10 saliva cases, 6 blood cases, and 1 lymphatic fluid case. This review also highlighted research gaps in oral squamous cell carcinoma (OSCC) EVs, including a lack of multi-omics studies and the exploration of potential EV markers for drug resistance, as well as a notable underutilization of microfluidic technologies to translate liquid biopsy EV findings into clinical applications.

Extracellular vesicles, including large translating vesicles called midbody remnants, are released during the cell cycle

Extracellular vesicles (EVs) play crucial roles in cell-cell communication, but the biogenesis of large EVs has remained elusive. Here, we show that the biogenesis of large EVs (>800 nm-2 µm) occurs predominantly through the completion of successful cytokinesis, and the majority of large EVs are midbody remnants (MBRs) with translation activity, and the unique marker MKLP1. Blocking the cell cycle or cytokinesis, genetically or chemically, significantly decreases MBRs and large (800 nm-2 µm), medium (500-800 nm), and small (<300 nm) EVs, suggesting that proliferative cells can also generate all sizes of EVs. The canonical EV markers including CD9, CD63, CD81 localize to the spindle midzone, midbody, and MBRs, suggesting that these markers are not specific for detecting EVs exclusively. Importantly, all commonly used EV isolation methods isolate MBRs, confounding previous EV research. Last, isolated MBRs maintain translation activity regardless of the isolation method. We propose a model for the biogenesis of EVs throughout the cell cycle and suggest that some large EVs are primarily generated from mitotic cells. The discovery of MBRs as a unique class of large, translating EVs has implications for using them as cancer diagnostic markers and for engineering them for therapeutic cargo delivery during mitosis.

Immune System-Related Plasma Pathogenic Extracellular Vesicle Subpopulations Predict Osteoarthritis Progression

Certain molecules found on the surface or within the cargo of extracellular vesicles (EVs) are linked to osteoarthritis (OA) severity and progression. We aimed to identify plasma pathogenic EV subpopulations that can predict knee radiographic OA (rOA) progression. We analyzed the mass spectrometry-based proteomic data of plasma EVs and synovial fluid (SF) EVs from knee OA patients (n = 16, 50% female). The identified surface markers of interest were further evaluated in plasma EVs from an independent cohort of knee OA patients (n = 30, 47% female) using flow cytometry. A total of 199 peptides with significant correlation between plasma and SF EVs were identified. Of these, 41.7% were linked to immune system processes, 15.5% to inflammatory responses, and 16.7% to the complement system. Crucially, five previously identified knee rOA severity-indicating surface markers-FGA, FGB, FGG, TLN1, and AMBP-were confirmed on plasma EV subpopulations in an independent cohort. These markers' baseline frequencies on large plasma EVs predicted rOA progression with an AUC of 0.655-0.711. Notably, TLN1 was expressed in OA joint tissue, whereas FGA, FGB, FGG, and AMBP were predominantly liver derived. These surface markers define specific pathogenic EV subpopulations, offering potential OA prognostic biomarkers and novel therapeutic targets for disease modification.

Exosomal miR-552-3p isolated from BALF of patients with silicosis induces fibroblast activation

BACKGROUND

Silica particles can cause silicosis, a disease characterized by diffuse fibrosis of the lungs. Various signaling pathways composed of different types of cells and cytokines are involved in the development of silicosis. Exosomes have become a research hotspot recently. However, the role of exosomal microRNA (miRNA) in silicosis remains unclear.

METHODS

In this study, we generated exosomal miRNA sequences from exosomes isolated from bronchoalveolar lavage fluid (BALF) of silicosis patients and the control group by high-throughput sequencing. Functional annotation and analysis of miRNA identified key target miRNAs. Levels of target miRNAs were analyzed in patient and animal samples and cells. Effects of increased miRNA were assessed through protein levels in target signaling pathways in cells treated with silica, miRNA mimics, and inhibitors.

RESULTS

Our study identified 40 up-regulated and 70 down-regulated miRNAs, with miR-552-3p and its putative target gene Caveolin 1 (CAV1) as targets for further research. We found that the levels of exosomal miR-552-3p increased in silicosis patients' BALF samples, silicosis model mice, and A549 cells exposed to silica. Inhibition of miR-552-3p suppressed the expression of fibrosis markers. The increased miR-552-3p leads to the up-regulation of fibronectin and α-smooth muscle actin (α-SMA) and the suppression of caveolin 1 in fibroblast cells. Mitogen-activated protein kinase (MAPK) signaling pathways are activated in cells treated with silica and miR-552-3p mimics.

CONCLUSIONS

These results help to understand exosomal miRNA-mediated intercellular communication and its key role in fibroblast activation and silicosis.

A deep learning method to integrate extracelluar miRNA with mRNA for cancer studies

MOTIVATION

Extracellular miRNAs (exmiRs) and intracellular mRNAs both can serve as promising biomarkers and therapeutic targets for various diseases. However, exmiR expression data is often noisy, and obtaining intracellular mRNA expression data usually involves intrusive procedures. To gain valuable insights into disease mechanisms, it is thus essential to improve the quality of exmiR expression data and develop noninvasive methods for assessing intracellular mRNA expression.

RESULTS

We developed CrossPred, a deep-learning multi-encoder model for the cross-prediction of exmiRs and mRNAs. Utilizing contrastive learning, we created a shared embedding space to integrate exmiRs and mRNAs. This shared embedding was then used to predict intracellular mRNA expression from noisy exmiR data and to predict exmiR expression from intracellular mRNA data. We evaluated CrossPred on three types of cancers and assessed its effectiveness in predicting the expression levels of exmiRs and mRNAs. CrossPred outperformed the baseline encoder-decoder model, exmiR or mRNA-based models, and variational autoencoder models. Moreover, the integration of exmiR and mRNA data uncovered important exmiRs and mRNAs associated with cancer. Our study offers new insights into the bidirectional relationship between mRNAs and exmiRs.

AVAILABILITY AND IMPLEMENTATION

The datasets and tool are available at https://doi.org/10.5281/zenodo.13891508.

Enhancing Extracellular Vesicle Detection via Cotargeting Tetraspanin Biomarkers

Extracellular vesicles (EVs) are emerging as key diagnostic biomarkers due to their widespread presence in body fluids and the proteins on their surfaces, which reflect the identity and condition of their parent cells. Research has focused on detecting EVs with biosensors that target individual transmembrane proteins (TMPs) like tetraspanins. However, due to TMP heterogeneity and the formation of tetraspanin-enriched microdomains (TEMs), cotargeting multiple TMPs is a promising strategy for enhancing EV detection. In this work, we introduce a dual-antibody surface functionalization approach using surface plasmon resonance (SPR) biosensors to cotarget tetraspanins on EVs derived from mouse macrophages. The expression of EV tetraspanin markers followed the trend of CD9 > CD63 > CD81, which was consistent with the EV detection targeting their nontetraspanin partners, exhibiting LFA-1 > ICAM-1 > VCAM-1, and suggesting a differential role of tetraspanins with their associated TMPs. Cotargeting EV tetraspanins via CD81/CD63, CD81/CD9, and CD63/CD9 dual monoclonal antibody surfaces resulted in higher EV detection compared to predictions based on binding with two monoclonal antibodies against tetraspanins without cotargeting. Furthermore, the optimization of dual monoclonal antibody surface ratios to improve cotargeting effect yielded a statistically significant enhancement in the sensitivity of EV detection. These findings underscore the importance of TEMs in designing EV-based biosensing platforms to achieve optimized sensitivity in EV detection.

Harmonising cellular conversations: decoding the vital roles of extracellular vesicles in respiratory system intercellular communications

Extracellular vesicles (EVs) released by various cells play crucial roles in intercellular communication within the respiratory system. This review explores the historical context and significance of research into extracellular vesicles. Categorised into exosomes (sized 30-150 nm), microvesicles (sized 50-1000 nm) and apoptotic bodies (sized 500-2000nm), based on their generation mechanisms, extracellular vesicles carry diverse cargoes of biomolecules, including proteins, lipids and nucleic acids. Respiratory ailments are the primary contributors to both mortality and morbidity across various populations globally, significantly impacting public health. Recent studies have underscored the pivotal role of extracellular vesicles, particularly their cargo content, in mediating intercellular communication between lung cells in respiratory diseases. This comprehensive review provides insights into extracellular vesicle mechanisms and emphasises their significance in major respiratory conditions, including acute lung injury, COPD, pulmonary hypertension, pulmonary fibrosis, asthma and lung cancer.

Bacterial Extracellular Vesicles: Potential Therapeutic Applications, Challenges, and Future Prospects

Almost all cell types naturally secret extracellular vesicles (EVs) in the extracellular space with variable metabolic cargo facilitating intracellular communication, posing immune-modulation capacity. Thus, "bacterial extracellular vesicles" (BEVs), with their great immunoregulatory, immune response stimulation and disease condition-altering potential, have gained importance in the medical and therapeutic industry. Various subtypes of BEVs were observed and reported in the literature, such as exosomes (30-150 nm), microvesicles (100-1000 nm), apoptotic bodies (1000-5000 nm), and oncosomes (1000-10,000 nm). As biological systems are complex entities, inserting BEVs requires extra high purity. Various techniques for BEV isolation have been employed alone or with other strategies, such as ultracentrifugation, precipitation, size-exclusion chromatography, affinity-based separation, ultrafiltration, and field-flow fractionation. But to date, no BEV isolation method is considered perfect as the lack of standard protocols limits their scale-up. Medical research has focused on BEVs to explore their diverse therapeutic potential. This review particularly focused on the recent advancements in the potential medical application of BEVs, current challenges, and prospects associated with their scale-up.

Unveiling exosomes: Cutting-edge isolation techniques and their therapeutic potential

Exosomes are one type of nanosized membrane vesicles with an endocytic origin. They are secreted by almost all cell types and play diverse functional roles. It is essential for research purposes to differentiate exosomes from microvesicles and isolate them from other components in a fluid sample or cell culture medium. Exosomes are important mediators in cell-cell communication. They deliver their cargos, such as mRNA transcripts, microRNA, lipids, cytosolic and membrane proteins and enzymes, to target cells with or without physical connections between cells. They are highly heterogeneous in size, and their biological functions can vary depending on the cell type, their ability to interact with recipient cells and transport their contents, and the environment in which they are produced. This review summarized the recent progress in exosome isolation and characterization techniques. Moreover, we review the therapeutic approaches, biological functions of exosomes in disease progression, tumour metastasis regulation, immune regulation and some ongoing clinical trials.

Biomarkers and diagnostic significance of non-coding RNAs in extracellular vesicles of pathologic pregnancy

Intercellular communication is an important mechanism for the development and maintenance of normal biological processes in all organs, including the female reproductive system. Extracellular vesicles, as important carriers of intercellular communication, contain a variety of biologically active molecules, such as mRNAs, miRNAs, lncRNAs, and circRNAs, which are involved in cell-to-cell exchanges as well as in many physiological and pathological processes in the body. Compared with biomarkers found in tissues or body fluids, extracellular vesicles show better stability due to the presence of their envelope membrane which prevents the degradation of the RNA message in their vesicles. Therefore, the genomic and proteomic information contained in extracellular vesicles can serve as important markers and potential therapeutic targets for female reproductive system-related diseases or placental function. Moreover, changes in the expression of non-coding RNAs (mainly miRNAs, lncRNAs, and circRNAs) in maternal extracellular vesicles can accurately and promptly reflect the progress of female reproductive system diseases. The aim of this review is to collect information on different types of non-coding RNAs with key molecular carriers in female pathologic pregnancies (preeclampsia and recurrent spontaneous abortion), so as to explore the relevant molecular mechanisms in female pathologic pregnancies and provide a theoretical basis for clinical research on the pathogenesis and therapeutic approaches of reproductive system diseases. The current state of the art of exosome isolation and extraction is also summarized.

Small Extracellular Vesicles and Oral Mucosa: The Power Couple in Regenerative Therapies?

Although ongoing debates persist over the scope of phenomena classified as regenerative processes, the most up-to-date definition of regeneration is the replacement or restoration of damaged or missing cells, tissues, organs, or body parts to full functionality. Despite extensive research on this topic, new methods in regenerative medicine are continually sought, and existing ones are being improved. Small extracellular vesicles (sEVs) have gained attention for their regenerative potential, as evidenced by existing studies conducted by independent research groups. Of particular interest are sEVs derived from the oral mucosa, a tissue renowned for its rapid regeneration and minimal scarring. While the individual regenerative potential of both sEVs and the oral mucosa is somewhat understood, the combined potential of sEVs derived from the oral mucosa has not been sufficiently explored and highlighted in the existing literature. Serving as a broad compendium, it aims to provide scientists with essential and detailed information on this subject, including the nature of the materials employed, isolation and analysis methodologies, and clinical applications. The content of this survey aims to facilitate the comparison of diverse methods for working with sEVs derived from the oral mucosa, aiding in the planning of research endeavors and identifying potential research gaps.

Circulating biomarkers for diagnosis and response to therapies in cancer patients

Cancer presents a significant challenge to global health, driving worldwide concerted efforts to advance early detection, predict therapeutic response, and identify novel targeted therapies. Liquid biopsies emerge as promising avenues for discerning cancer biomarkers, offering less invasive approaches compared to conventional methods. Utilizing increasingly robust technologies, diverse bodily fluids can unveil genetic variants, epigenetic modifications, transcriptional alterations, and metabolomic signatures associated with cancer, thereby furnishing valuable insights for clinical management. This chapter intends to review the sources of cancer-related biomarkers found in circulation, prevalent techniques utilized for their identification, and the potential implications of different biomarker types on the management of cancer. Certain biomarkers currently used in clinical practice will be addressed, as well as potential biomarkers still in the study phase, and the inherent challenges in their practical implementation.

Bacteriophages and bacterial extracellular vesicles, threat or opportunity?

Emergence of antimicrobial-resistant bacteria (AMR) is one of the health major problems worldwide. The scientists are looking for a novel method to treat infectious diseases. Phage therapy is considered a suitable approach for treating infectious diseases. However, there are different challenges in this way. Some biological aspects can probably influence on therapeutic results and further investigations are necessary to reach a successful phage therapy. Bacteriophage activity can influence by bacterial defense system. Bacterial extracellular vesicles (BEVs) are one of the bacterial defense mechanisms which can modify the results of bacteriophage activity. BEVs have the significant roles in the gene transferring, invasion, escape, and spreading of bacteriophages. In this review, the defense mechanisms of bacteria against bacteriophages, especially BEVs secretion, the hidden linkage of BEVs and bacteriophages, and its possible consequences on the bacteriophage activity as well phage therapy will be discussed.

Eosinophil-derived extracellular vesicles: isolation and classification techniques and implications for disease pathophysiology

Eosinophils are leukocytes characterized by their ability to release granule content that is highly rich in enzymes and proteins. Besides the antihelminthic, bactericidal, and antiviral properties of eosinophils and their secretory granules, these also play a prominent role in the pathophysiology of diseases such as asthma, eosinophilic esophagitis, and other hypereosinophilic conditions by causing tissue damage and airway hyperresponsiveness. Although this cell was first recognized mainly for its capacity to release granule content, nowadays other capabilities such as cytokine secretion have been linked to its physiology, and research has found that eosinophils are not only involved in innate immunity, but also as orchestrators of immune responses. Nearly 10 yr ago, eosinophil-derived extracellular vesicles (EVs) were first described; since then, the EV field has grown exponentially, revealing their vital roles in intracellular communication. In this review, we synthesize current knowledge on eosinophil-derived EVs, beginning with a description of what they are and what makes them important regulators of disease, followed by an account of the methodologies used to isolate and characterize EVs. We also summarize current understanding of eosinophil-derived vesicles functionality, especially in asthma, the disease in which eosinophil-derived EVs have been most widely studied, describing how they modulate the role of eosinophils themselves (through autocrine signaling) and the way they affect airway structural cells and airway remodeling. Deeper understanding of this cell type could lead to novel research in eosinophil biology, its role in other diseases, and possible use of eosinophil-derived EVs as therapeutic targets.

Exploring Synergistic Effects of Bioprinted Extracellular Vesicles for Skin Regeneration

Regenerative medicine represents a paradigm shift in healthcare, aiming to restore tissue and organ function through innovative therapeutic strategies. Among these, bioprinting and extracellular vesicles (EVs) have emerged as promising techniques for tissue rejuvenation. EVs are small lipid membrane particles secreted by cells, known for their role as potent mediators of intercellular communication through the exchange of proteins, genetic material, and other biological components. The integration of 3D bioprinting technology with EVs offers a novel approach to tissue engineering, enabling the precise deposition of EV-loaded bioinks to construct complex three-dimensional (3D) tissue architectures. Unlike traditional cell-based approaches, bioprinted EVs eliminate the need for live cells, thereby mitigating regulatory and financial obstacles associated with cell therapy. By leveraging the synergistic effects of EVs and bioprinting, researchers aim to enhance the therapeutic outcomes of skin regeneration while addressing current limitations in conventional treatments. This review explores the evolving landscape of bioprinted EVs as a transformative approach for skin regeneration. Furthermore, it discusses the challenges and future directions in harnessing this innovative therapy for clinical applications, emphasizing the need for interdisciplinary collaboration and continued scientific inquiry to unlock its full therapeutic potential.

Comparison of the efficiency of ultrafiltration, precipitation, and ultracentrifugation methods for exosome isolation

Extracellular vesicles (EVs) are enclosed by a lipid-bilayer membrane and secreted by all types of cells. They are classified into three groups: apoptotic bodies, microvesicles, and exosomes. Exosomes play a number of important roles in the intercellular communication and crosstalk between tissues in the body. In this study, we use three common methods based on different principles for exosome isolation, namely ultrafiltration, precipitation, and ultracentrifugation. We use field emission scanning electron microscopy (FESEM) and dynamic light scattering (DLS) analyses for characterization of exosomes. The functionality and effect of isolated exosomes on the viability of hypoxic cells was investigated by alamarBlue and Flow-cytometry. The results of the FESEM study show that the ultrafiltration method isolates vesicles with higher variability of shapes and sizes when compared to the precipitation and ultracentrifugation methods. DLS results show that mean size of exosomes isolated by ultrafiltration, precipitation, and ultracentrifugation methods are 122, 89, and 60 nm respectively. AlamarBlue analysis show that isolated exosomes increase the viability of damaged cells by 11%, 15%, and 22%, respectively. Flow-cytometry analysis of damaged cells also show that these vesicles increase the content of live cells by 9%, 15%, and 20%, respectively. This study shows that exosomes isolated by the ultracentrifugation method are characterized by smaller size and narrow size distribution. Furthermore, more homogenous particles isolated by this method show increased efficiency of the protection of hypoxic cells in comparison with the exosomes isolated by the two other methods.

The role and application of small extracellular vesicles in glioma

Small extracellular vesicles (sEVs) are cell-derived, nanometer-sized particles enclosed by a lipid bilayer. All kinds of biological molecules, including proteins, DNA fragments, RNA, lipids, and metabolites, can be selectively loaded into sEVs and transmitted to recipient cells that are near and distant. Growing shreds of evidence show the significant biological function and the clinical significance of sEVs in cancers. Numerous recent studies have validated that sEVs play an important role in tumor progression and can be utilized to diagnose, stage, grading, and monitor early tumors. In addition, sEVs have also served as drug delivery nanocarriers and cancer vaccines. Although it is still infancy, the field of basic and translational research based on sEVs has grown rapidly. In this review, we summarize the latest research on sEVs in gliomas, including their role in the malignant biological function of gliomas, and the potential of sEVs in non-invasive diagnostic and therapeutic approaches, i.e., as nanocarriers for drug or gene delivery and cancer vaccines.

Cargo exchange between human and bacterial extracellular vesicles in gestational tissues: a new paradigm in communication and immune development

Host-bacteria and bacteria-bacteria interactions can be facilitated by extracellular vesicles (EVs) secreted by both human and bacterial cells. Human and bacterial EVs (BEVs) propagate and transfer immunogenic cargos that may elicit immune responses in nearby or distant recipient cells/tissues. Hence, direct colonization of tissues by bacterial cells is not required for immunogenic stimulation. This phenomenon is important in the feto-maternal interface, where optimum tolerance between the mother and fetus is required for a successful pregnancy. Though the intrauterine cavity is widely considered sterile, BEVs from diverse sources have been identified in the placenta and amniotic cavity. These BEVs can be internalized by human cells, which may help them evade host immune surveillance. Though it appears logical, whether bacterial cells internalize human EVs or human EV cargo is yet to be determined. However, the presence of BEVs in placental tissues or amniotic cavity is believed to trigger a low-grade immune response that primes the fetal immune system for ex-utero survival, but is insufficient to disrupt the progression of pregnancy or cause immune intolerance required for adverse pregnancy events. Nevertheless, the exchange of bioactive cargos between human and BEVs, and the mechanical underpinnings and health implications of such interactions, especially during pregnancy, are still understudied. Therefore, while focusing on the feto-maternal interface, we discussed how human cells take up BEVs and whether bacterial cells take up human EVs or their cargo, the exchange of cargos between human and BEVs, host cell (feto-maternal) inflammatory responses to BEV immunogenic stimulation, and associations of these interactions with fetal immune priming and adverse reproductive outcomes such as preeclampsia and preterm birth.

Extracellular Vesicles: An Emerging Clinical Opportunity in Musculoskeletal Disease

Extracellular vesicles (EVs) are important mediators of cell-to-cell communication in the extracellular space. These membranous nanoparticles carry various molecules, often referred to as "cargo," which are delivered to nearby target cells. In the past decade, developments in nanotechnology have allowed for various new laboratory techniques for the increased utilization of EVs in cellular and animal studies. Such techniques have evolved for the isolation, characterization, and delivery of EVs to biological tissues. This emerging technology has immense clinical potential for both diagnostic and therapeutic applications. Various EV cargo molecules, including DNA, RNA, and proteins, can act as pathological biomarkers. Furthermore, EVs derived from certain cell sources have shown therapeutic benefit in certain pathologies. In addition to their native therapeutic benefit, EVs can be engineered to carry and selectively deliver therapeutic agents. While EVs have gained increasing interest in various pathologies, few studies have compiled their clinical potential in musculoskeletal pathologies. To bridge this gap, we present an overview of EVs, introduce current laboratory preparation techniques, and outline the most recent literature regarding the potential therapeutic applications of EVs in musculoskeletal pathologies.

Decreased serpin C1 in extracellular vesicles predicts response to methotrexate treatment in patients with pulmonary sarcoidosis

BACKGROUND

Sarcoidosis is a systemic granulomatous disease of unknown etiology primarily affecting the lungs. Treatment is needed when disease symptoms worsen and organ function deteriorates. In pulmonary sarcoidosis, prednisone and methotrexate (MTX) are the most common anti-inflammatory therapies. However, there is large inter-patient variability in response to treatment, and predictive response markers are currently lacking.

OBJECTIVE

In this study, we investigated the predictive potential of biomarkers in extracellular vesicles (EVs) isolated from biobanked serum of patients with pulmonary sarcoidosis stored prior to start of therapy.

METHODS

Protein concentrations of a four-protein test panel of inflammatory proteins were measured in a discovery (n = 16) and replication (n = 129) cohort of patients with sarcoidosis and 47 healthy controls. Response to therapy was defined as an improvement of the absolute score of > 5% forced vital capacity (FVC) and/or > 10% diffusion lung of carbon monoxide (DLCO) after 24 weeks compared to baseline (before treatment).

RESULTS

Serum protein levels differed between EV fractions and serum, and between sarcoidosis cases and controls. Serpin C1 concentrations in the low density lipid particle EV fraction were lower at baseline in the group of patients with a good response to MTX treatment in both the discovery cohort (p = 0.059) and in the replication cohort (p = 0.032). EV Serpin C1 showed to be a significant predictor for response to treatment with MTX (OR 0.4; p = 0.032).

CONCLUSION

This study shows that proteins isolated from EVs harbor a distinct signal and have potential as new predictive therapy response biomarkers in sarcoidosis.

Targeted drug delivery of engineered mesenchymal stem/stromal-cell-derived exosomes in cardiovascular disease: recent trends and future perspectives

In recent years, stem cells and their secretomes, notably exosomes, have received considerable attention in biomedical applications. Exosomes are cellular secretomes used for intercellular communication. They perform the function of intercellular messengers by facilitating the transport of proteins, lipids, nucleic acids, and therapeutic substances. Their biocompatibility, minimal immunogenicity, targetability, stability, and engineerable characteristics have additionally led to their application as drug delivery vehicles. The therapeutic efficacy of exosomes can be improved through surface modification employing functional molecules, including aptamers, antibodies, and peptides. Given their potential as targeted delivery vehicles to enhance the efficiency of treatment while minimizing adverse effects, exosomes exhibit considerable promise. Stem cells are considered advantageous sources of exosomes due to their distinctive characteristics, including regenerative and self-renewal capabilities, which make them well-suited for transplantation into injured tissues, hence promoting tissue regeneration. However, there are notable obstacles that need to be addressed, including immune rejection and ethical problems. Exosomes produced from stem cells have been thoroughly studied as a cell-free strategy that avoids many of the difficulties involved with cell-based therapy for tissue regeneration and cancer treatment. This review provides an in-depth summary and analysis of the existing knowledge regarding exosomes, including their engineering and cardiovascular disease (CVD) treatment applications.

The efficacy of extracellular vesicles for acute lung injury in preclinical animal models: a meta-analysis

BACKGROUND

With the increasing research on extracellular vesicles (EVs), EVs have received widespread attention as biodiagnostic markers and therapeutic agents for a variety of diseases. Stem cell-derived EVs have also been recognized as a new viable therapy for acute lung injury (ALI) and acute respiratory distress syndrome (ARDS). To assess their efficacy, we conducted a meta-analysis of existing preclinical experimental animal models of EVs for ALI treatment.

METHODS

The database was systematically interrogated for pertinent data encompassing the period from January 2010 to April 2022 concerning interventions involving extracellular vesicles (EVs) in animal models of acute lung injury (ALI). The lung injury score was selected as the primary outcome measure for statistical analysis. Meta-analyses were executed utilizing RevMan 5.3 and State15.1 software tools.

RESULTS

The meta-analyses comprised 31 studies, exclusively involving animal models of acute lung injury (ALI), categorized into two cohorts based on the presence or absence of extracellular vesicle (EV) intervention. The statistical outcomes from these two study groups revealed a significant reduction in lung injury scores with the administration of stem and progenitor cell-derived EVs (SMD = -3.63, 95% CI [-4.97, -2.30], P < 0.05). Conversely, non-stem cell-derived EVs were associated with an elevation in lung injury scores (SMD = -4.34, 95% CI [3.04, 5.63], P < 0.05). EVs originating from stem and progenitor cells demonstrated mitigating effects on alveolar neutrophil infiltration, white blood cell counts, total cell counts in bronchoalveolar lavage fluid (BALF), lung wet-to-dry weight ratios (W/D), and total protein in BALF. Furthermore, pro-inflammatory mediators exhibited down-regulation, while anti-inflammatory mediators demonstrated up-regulation. Conversely, non-stem cell-derived EVs exacerbated lung injury.

CONCLUSION

In preclinical animal models of acute lung injury (ALI), the administration of extracellular vesicles (EVs) originating from stem and progenitor cells demonstrably enhances pulmonary function. This ameliorative effect is attributed to the mitigation of pulmonary vascular permeability and the modulation of immune homeostasis, collectively impeding the progression of inflammation. In stark contrast, the utilization of EVs derived from non-stem progenitor cells exacerbates the extent of lung injury. These findings substantiate the potential utility of EVs as a novel therapeutic avenue for addressing acute lung injury.

Cell Type-Specific Extracellular Vesicles and Their Impact on Health and Disease

Extracellular vesicles (EVs), a diverse group of cell-derived exocytosed particles, are pivotal in mediating intercellular communication due to their ability to selectively transfer biomolecules to specific cell types. EVs, composed of proteins, nucleic acids, and lipids, are taken up by cells to affect a variety of signaling cascades. Research in the field has primarily focused on stem cell-derived EVs, with a particular focus on mesenchymal stem cells, for their potential therapeutic benefits. Recently, tissue-specific EVs or cell type-specific extracellular vesicles (CTS-EVs), have garnered attention for their unique biogenesis and molecular composition because they enable highly targeted cell-specific communication. Various studies have outlined the roles that CTS-EVs play in the signaling for physiological function and the maintenance of homeostasis, including immune modulation, tissue regeneration, and organ development. These properties are also exploited for disease propagation, such as in cancer, neurological disorders, infectious diseases, autoimmune conditions, and more. The insights gained from analyzing CTS-EVs in different biological roles not only enhance our understanding of intercellular signaling and disease pathogenesis but also open new avenues for innovative diagnostic biomarkers and therapeutic targets for a wide spectrum of medical conditions. This review comprehensively outlines the current understanding of CTS-EV origins, function within normal physiology, and implications in diseased states.

Bacteria-derived extracellular vesicles: endogenous roles, therapeutic potentials and their biomimetics for the treatment and prevention of sepsis

Sepsis is one of the medical conditions with a high mortality rate and lacks specific treatment despite several years of extensive research. Bacterial extracellular vesicles (bEVs) are emerging as a focal target in the pathophysiology and treatment of sepsis. Extracellular vesicles (EVs) derived from pathogenic microorganisms carry pathogenic factors such as carbohydrates, proteins, lipids, nucleic acids, and virulence factors and are regarded as "long-range weapons" to trigger an inflammatory response. In particular, the small size of bEVs can cross the blood-brain and placental barriers that are difficult for pathogens to cross, deliver pathogenic agents to host cells, activate the host immune system, and possibly accelerate the bacterial infection process and subsequent sepsis. Over the years, research into host-derived EVs has increased, leading to breakthroughs in cancer and sepsis treatments. However, related approaches to the role and use of bacterial-derived EVs are still rare in the treatment of sepsis. Herein, this review looked at the dual nature of bEVs in sepsis by highlighting their inherent functions and emphasizing their therapeutic characteristics and potential. Various biomimetics of bEVs for the treatment and prevention of sepsis have also been reviewed. Finally, the latest progress and various obstacles in the clinical application of bEVs have been highlighted.

Extracellular vesicles from BALF of pediatric cystic fibrosis and asthma patients increase epithelial sodium channel activity in small airway epithelial cells

Extracellular Vesicles (EVs) are nanosized vesicles derived from all cell types. EV cargo allows for intercellular communication, intracellular signaling, and regulation of proteins in recipient cells. We tested the hypothesis that EVs isolated from the bronchoalveolar-lavage fluid (BALF) of pediatric cystic fibrosis (CF) or pediatric asthma patients increase epithelial sodium channel (ENaC) activity in normal human small airway epithelial cells (SAECs) and the mechanism involves specific EV lipids. We characterized EVs from BALF of pediatric CF and pediatric asthma patients by nanoparticle tracking analysis, transmission electron microscopy, and Western blotting. The CF and asthma pediatric groups were similar in BALF electrolytes concentration and cell count, except for neutrophils, which were higher in the CF group. Lipidomic analyses for each group of EVs were performed using targeted mass spectrometry. Phosphatidylethanolamine, sphingomyelins, and triacylglycerol were enriched in both groups, but phosphatidylcholine and phosphatidylinositol concentrations were greater in the CF group compared to the asthma group, and the opposite trend was found for phosphatidylserine. Endogenous ENaC activity, measured by the single-channel patch-clamp technique, increased in normal human SAECs after challenging SAEC with EVs from either the CF or asthma groups compared to control EVs. In conclusion, EVs isolated from BALF of pediatric patients with CF or asthma have unique lipid profiles. Despite the differences, both types of EVs increase ENaC activity in normal human SAECs compared to control EVs isolated from the conditioned media of these cells.

Bronchoalveolar lavage fluid assessment facilitates precision medicine for lung cancer

Lung cancer is the most common and fatal malignant disease worldwide and has the highest mortality rate among tumor-related causes of death. Early diagnosis and precision medicine can significantly improve the survival rate and prognosis of lung cancer patients. At present, the clinical diagnosis of lung cancer is challenging due to a lack of effective non-invasive detection methods and biomarkers, and treatment is primarily hindered by drug resistance and high tumor heterogeneity. Liquid biopsy is a method for detecting circulating biomarkers in the blood and other body fluids containing genetic information from primary tumor tissues. Bronchoalveolar lavage fluid (BALF) is a potential liquid biopsy medium that is rich in a variety of bioactive substances and cell components. BALF contains information on the key characteristics of tumors, including the tumor subtype, gene mutation type, and tumor environment, thus BALF may be used as a diagnostic supplement to lung biopsy. In this review, the current research on BALF in the diagnosis, treatment, and prognosis of lung cancer is summarized. The advantages and disadvantages of different components of BALF, including cells, cell-free DNA, extracellular vesicles, and microRNA are introduced. In particular, the great potential of extracellular vesicles in precision diagnosis and detection of drug-resistant for lung cancer is highlighted. In addition, the performance of liquid biopsies with different body fluid sources in lung cancer detection are compared to facilitate more selective studies involving BALF, thereby promoting the application of BALF for precision medicine in lung cancer patients in the future.

Mesenchymal Stem Cells‐Derived Extracellular Vesicles in Orthopedic Diseases: Recent Advances and Therapeutic Potential

Ever since the first application of mesenchymal stem cell (MSC) transplantation treating human hematologic malignancies in 1995, MSC‐based treatments have demonstrated great therapeutic potential in clinical settings. However, only a few MSC‐based cell therapy products have been clinically approved. Accumulating evidence suggests that the beneficial effects of MSCs are mainly attributed to the release of paracrine factors or extracellular vesicles (EVs) rather than their mesodermal differentiation potential. Therefore, MSC‐derived EVs (MSC‐EVs), such as exosomes and microvesicles, have merged as promising alternatives to traditional cell‐based therapeutics in clinical practice. They offer several advantages such as better safety, lower immunogenicity, protection of cargoes from degradation, and the ability to overcome biological barriers. Moreover, there have been multiple clinical studies exploring the potential of MSC‐EVs for treating various diseases, including orthopedic disorders. However, there is no definitive “cure” for conditions such as osteoporosis and other bone disorders, but MSC‐EVs have displayed significant therapeutic potential for these orthopedic ailments. Therefore, the objective of this study is to conduct a systematic review of current knowledge related to MSC‐EVs and emphasize their potential application in treating orthopedic diseases, such as bone defects, osteoarthritis, osteoporosis, intervertebral disc degeneration, osteosarcoma, and osteoradionecrosis.

Comprehensive characterization of pathogenic synovial fluid extracellular vesicles from knee osteoarthritis

Synovial fluid (SF) extracellular vesicles (EVs) play a pathogenic role in osteoarthritis (OA). However, the surface markers, cell and tissue origins, and effectors of these EVs are largely unknown. We found that SF EVs contained 692 peptides that were positively associated with knee radiographic OA severity; 57.4% of these pathogenic peptides were from 46 proteins of the immune system, predominantly the innate immune system. CSPG4, BGN, NRP1, and CD109 are the major surface markers of pathogenic SF EVs. Genes encoding surface marker CSPG4 and CD109 were highly expressed by chondrocytes from damaged cartilage, while VISG4, MARCO, CD163 and NRP1 were enriched in the synovial immune cells. The frequency of CSPG4+ and VSIG4+ EV subpopulations in OA SF was high. We conclude that pathogenic SF EVs carry knee OA severity-associated proteins and specific surface markers, which could be developed as a new source of diagnostic biomarkers or therapeutic targets in OA.

Innovative preconditioning strategies for improving the therapeutic efficacy of extracellular vesicles derived from mesenchymal stem cells in gastrointestinal diseases

Gastrointestinal (GI) diseases have become a global health issue and an economic burden due to their wide distribution, late prognosis, and the inefficacy of recent available medications. Therefore, it is crucial to search for new strategies for their management. In the recent decades, mesenchymal stem cells (MSCs) therapy has attracted attention as a viable option for treating a myriad of GI disorders such as hepatic fibrosis (HF), ulcerative colitis (UC), acute liver injury (ALI), and non-alcoholic fatty liver disease (NAFLD) due to their regenerative and paracrine properties. Importantly, recent studies have shown that MSC-derived extracellular vesicles (MSC-EVs) are responsible for most of the therapeutic effects of MSCs. In addition, EVs have revealed several benefits over their parent MSCs, such as being less immunogenic, having a lower risk of tumour formation, being able to cross biological barriers, and being easier to store. MSC-EVs exhibited regenerative, anti-oxidant, anti-inflammatory, anti-apoptotic, and anti-fibrotic effects in different experimental models of GI diseases. However, a key issue with their clinical application is the maintenance of their stability and efficacy following in vivo transplantation. Preconditioning of MSC-EVs or their parent cells is one of the novel methods used to improve their effectiveness and stability. Herein, we discuss the application of MSC-EVs in several GI disorders taking into account their mechanism of action. We also summarise the challenges and restrictions that need to be overcome to promote their clinical application in the treatment of various GI diseases as well as the recent developments to improve their effectiveness. A representation of the innovative preconditioning techniques that have been suggested for improving the therapeutic efficacy of MSC-EVs in GI diseases. The pathological conditions in various GI disorders (ALI, UC, HF and NAFLD) create a harsh environment for EVs and their parents, increasing the risk of apoptosis and senescence of MSCs and thereby diminishing MSC-EVs yield and restricting their large-scale applications. Preconditioning with pharmacological agents or biological mediators can improve the therapeutic efficacy of MSC-EVs through their adaption to the lethal environment to which they are subjected. This can result in establishment of a more conducive environment and activation of numerous vital trajectories that act to improve the immunomodulatory, reparative and regenerative activities of the derived EVs, as a part of MSCs paracrine system. ALI, acute liver injury; GI diseases, gastrointestinal diseases; HF, hepatic fibrosis; HSP, heat shock protein; miRNA, microRNA; mRNA, messenger RNA; MSC-EVs, mesenchymal stem cell-derived extracellular vesicles; NAFLD, non-alcoholic fatty liver disease; UC, ulcerative colitis.

Exploring the Versatility of Exosomes: A Review on Isolation, Characterization, Detection Methods, and Diverse Applications

Extracellular vesicles (EVs) are crucial mediators of intercellular communication and can be classified based on their physical properties, biomolecular structure, and origin. Among EVs, exosomes have garnered significant attention due to their potential as therapeutic and diagnostic tools. Exosomes are released via fusion of multivesicular bodies on plasma membranes and can be isolated from various biofluids using methods such as differential ultracentrifugation, immune affinity capture, ultrafiltration, and size exclusion chromatography. Herein, an overview of different techniques for exosome characterization and isolation, as well as the diverse applications of exosome detection, including their potential use in drug delivery and disease diagnosis, is provided. Additionally, we discuss the emerging field of exosome detection by sensors, which offers an up-and-coming avenue for point-of-care diagnostic tools development. Overall, this review aims to provide a exhaustive and up-to-date summary of the current state of exosome research.

Recent engineering advances of EVs for compounds, nucleic acids, and TCM delivery

Extracellular vesicles (EVs) are phospholipid bilayer nano-vesicles that were originally identified to deliver signals for intercellular communications. Based on the dynamic contents including proteins, nucleic acids and metabolites, EVs have been developed into diagnostic and therapeutic fields including cardiovascular diseases, neurological disorders and infectious diseases. A growing number of investigations revealed that EVs are also powerful carriers of loaded compounds and nucleic acids as enhanced treatments. Herein, we summarized the recent engineering advances related to three major issues when applying EVs in drug delivery systems: EVs isolation, drug loading strategies and targeting delivery approaches. Moreover, current applications of traditional Chinese medicine (TCM), in composition or compound form, are searched and listed as unique combinations with EVs. Further, we discuss emerging challenges and consider future directions of drug-loading EVs in therapeutic opportunities. This review discusses pros and cons of collecting, drug loading and delivery strategies of EVs as delivery systems, and highlights the promising combination with traditional Chinese medicine to help us advance its clinical application.

Extracellular vesicles and their non-coding RNA cargos: Emerging players in cardiovascular disease

Extracellular vesicles (EVs), including exosomes, microvesicles and apoptotic bodies, have recently received attention as essential mechanisms for cell-to-cell communication in cardiovascular disease. EVs can be released from different types of cells, including endothelial cells, smooth muscle cells, cardiac cells, fibroblasts, platelets, adipocytes, immune cells and stem cells. Non-coding (nc)RNAs as EV cargos have recently been investigated in the cardiovascular system. Up- or downregulated ncRNAs in EVs have been shown to play a crucial role in various cardiovascular diseases. Communication via EV-derived ncRNAs can occur between cells of the same type and between different types of cells involved in the pathophysiology of cardiovascular disease. In the present review, we highlight the important aspects of diverse cell-derived EVs and their ncRNA cargos as disease mediators and potential therapeutic targets in atherosclerosis, coronary artery disease, ischaemic heart disease and cardiac fibrosis. In addition, we summarize the potential of EV-derived ncRNAs in the treatment of cardiovascular disease. Finally, we discuss the different methods for EV isolation and characterization. A better understanding of the specific role of EVs and their ncRNA cargos in the regulation of cardiovascular (dys)function will be of importance for the development of diagnostic and therapeutic tools for cardiovascular disease.

Engineered Exosomes as Theranostic Platforms for Cancer Treatment

Tremendous progress in nanotechnology and nanomedicine has made a significant positive effect on cancer treatment by integrating multicomponents into a single multifunctional nanosized delivery system for combinatorial therapies. Although numerous nanocarriers developed so far have achieved excellent therapeutic performance in mouse models via elegant integration of chemotherapy, photothermal therapy, photodynamic therapy, sonodynamic therapy, and immunotherapy, their synthetic origin may still cause systemic toxicity, immunogenicity, and preferential detection or elimination by the immune system. Exosomes, endogenous nanosized particles secreted by multiple biological cells, could be absorbed by recipient cells to facilitate intercellular communication and content delivery. Therefore, exosomes have emerged as novel cargo delivery tools and attracted considerable attention for cancer diagnosis and treatment due to their innate stability, biological compatibility, and biomembrane penetration capacity. Exosome-related properties and functions have been well-documented; however, there are few reviews, to our knowledge, with a focus on the combination of exosomes and nanotechnology for the development of exosome-based theranostic platforms. To make a timely review on this hot subject of research, we summarize the basic information, isolation and functionalization methodologies, diagnostic and therapeutic potential of exosomes in various cancers with an emphasis on the description of exosome-related nanomedicine for cancer theranostics. The existing appealing challenges and outlook in exosome clinical translation are finally introduced. Advanced biotechnology and nanotechnology will definitely not only promote the integration of intrinsic advantages of natural nanosized exosomes with traditional synthetic nanomaterials for modulated precise cancer treatment but also contribute to the clinical translations of exosome-based nanomedicine as theranostic nanoplatforms.

Beyond Macromolecules: Extracellular Vesicles as Regulators of Inflammatory Diseases

Inflammation is the defense mechanism of the immune system against harmful stimuli such as pathogens, toxic compounds, damaged cells, radiation, etc., and is characterized by tissue redness, swelling, heat generation, pain, and loss of tissue functions. Inflammation is essential in the recruitment of immune cells at the site of infection, which not only aids in the elimination of the cause, but also initiates the healing process. However, prolonged inflammation often brings about several chronic inflammatory disorders; hence, a balance between the pro- and anti-inflammatory responses is essential in order to eliminate the cause while producing the least damage to the host. A growing body of evidence indicates that extracellular vesicles (EVs) play a major role in cell-cell communication via the transfer of bioactive molecules in the form of proteins, lipids, DNA, RNAs, miRNAs, etc., between the cells. The present review provides a brief classification of the EVs followed by a detailed description of how EVs contribute to the pathogenesis of various inflammation-associated diseases and their implications as a therapeutic measure. The latter part of the review also highlights how EVs act as a bridging entity in blood coagulation disorders and associated inflammation. The findings illustrated in the present review may open a new therapeutic window to target EV-associated inflammatory responses, thereby minimizing the negative outcomes.

Systematic Assessment of Small RNA Profiling in Human Extracellular Vesicles

MOTIVATION

Extracellular vesicles (EVs) are produced and released by most cells and are now recognized to play a role in intercellular communication through the delivery of molecular cargo, including proteins, lipids, and RNA. Small RNA sequencing (small RNA-seq) has been widely used to characterize the small RNA content in EVs. However, there is a lack of a systematic assessment of the quality, technical biases, RNA composition, and RNA biotypes enrichment for small RNA profiling of EVs across cell types, biofluids, and conditions.

METHODS

We collected and reanalyzed small RNA-seq datasets for 2756 samples from 83 studies involving 55 with EVs only and 28 with both EVs and matched donor cells. We assessed their quality by the total number of reads after adapter trimming, the overall alignment rate to the host and non-host genomes, and the proportional abundance of total small RNA and specific biotypes, such as miRNA, tRNA, rRNA, and Y RNA.

RESULTS

We found that EV extraction methods varied in their reproducibility in isolating small RNAs, with effects on small RNA composition. Comparing proportional abundances of RNA biotypes between EVs and matched donor cells, we discovered that rRNA and tRNA fragments were relatively enriched, but miRNAs and snoRNA were depleted in EVs. Except for the export of eight miRNAs being context-independent, the selective release of most miRNAs into EVs was study-specific.

CONCLUSION

This work guides quality control and the selection of EV isolation methods and enhances the interpretation of small RNA contents and preferential loading in EVs.

Circulating extracellular vesicles promote recovery in a preclinical model of intracerebral hemorrhage

Circulating extracellular vesicles (EVs) are proposed to participate in enhancing pathways of recovery after stroke through paracrine signaling. To verify this hypothesis in a proof-of-concept study, blood-derived allogenic EVs from rats and xenogenic EVs from humans who experienced spontaneous good recovery after an intracerebral hemorrhage (ICH) were administered intravenously to rats at 24 h after a subcortical ICH. At 28 days, both treatments improved the motor function assessment scales score, showed greater fiber preservation in the perilesional zone (diffusion tensor-fractional anisotropy MRI), increased immunofluorescence markers of myelin (MOG), and decreased astrocyte markers (GFAP) compared with controls. Comparison of the protein cargo of circulating EVs at 28 days from animals with good vs. poor recovery showed down-expression of immune system activation pathways (CO4, KLKB1, PROC, FA9, and C1QA) and of restorative processes such as axon guidance (RAC1), myelination (MBP), and synaptic vesicle trafficking (SYN1), which is in line with better tissue preservation. Up-expression of PCSK9 (neuron differentiation) in xenogenic EVs-treated animals suggests enhancement of repair pathways. In conclusion, the administration of blood-derived EVs improved recovery after ICH. These findings open a new and promising opportunity for further development of restorative therapies to improve the outcomes after an ICH.

CD11b Deficiency Favors Cartilage Calcification via Increased Matrix Vesicles, Apoptosis, and Lysyl Oxidase Activity

Pathological cartilage calcification is a hallmark feature of osteoarthritis, a common degenerative joint disease, characterized by cartilage damage, progressively causing pain and loss of movement. The integrin subunit CD11b was shown to play a protective role against cartilage calcification in a mouse model of surgery-induced OA. Here, we investigated the possible mechanism by which CD11b deficiency could favor cartilage calcification by using naïve mice. First, we found by transmission electron microscopy (TEM) that CD11b KO cartilage from young mice presented early calcification spots compared with WT. CD11b KO cartilage from old mice showed progression of calcification areas. Mechanistically, we found more calcification-competent matrix vesicles and more apoptosis in both cartilage and chondrocytes isolated from CD11b-deficient mice. Additionally, the extracellular matrix from cartilage lacking the integrin was dysregulated with increased collagen fibrils with smaller diameters. Moreover, we revealed by TEM that CD11b KO cartilage had increased expression of lysyl oxidase (LOX), the enzyme that catalyzes matrix crosslinks. We confirmed this in murine primary CD11b KO chondrocytes, where Lox gene expression and crosslinking activity were increased. Overall, our results suggest that CD11b integrin regulates cartilage calcification through reduced MV release, apoptosis, LOX activity, and matrix crosslinking. As such, CD11b activation might be a key pathway for maintaining cartilage integrity.

Extracellular vesicle-mediated intercellular and interorgan crosstalk of pancreatic islet in health and diabetes

Diabetes mellitus (DM) is a systemic metabolic disease with high mortality and morbidity. Extracellular vesicles (EVs) have emerged as a novel class of signaling molecules, biomarkers and therapeutic agents. EVs-mediated intercellular and interorgan crosstalk of pancreatic islets plays a crucial role in the regulation of insulin secretion of β-cells and insulin action in peripheral insulin target tissues, maintaining glucose homeostasis under physiological conditions, and it's also involved in pathological changes including autoimmune response, insulin resistance and β-cell failure associated with DM. In addition, EVs may serve as biomarkers and therapeutic agents that respectively reflect the status and improve function and viability of pancreatic islets. In this review, we provide an overview of EVs, discuss EVs-mediated intercellular and interorgan crosstalk of pancreatic islet under physiological and diabetic conditions, and summarize the emerging applications of EVs in the diagnosis and treatment of DM. A better understanding of EVs-mediated intercellular and interorgan communication of pancreatic islets will broaden and enrich our knowledge of physiological homeostasis maintenance as well as the development, diagnosis and treatment of DM.

Bioprinting extracellular vesicles as a "cell-free" regenerative medicine approach

Regenerative medicine involves the restoration of tissue or organ function via the regeneration of these structures. As promising regenerative medicine approaches, either extracellular vesicles (EVs) or bioprinting are emerging stars to regenerate various tissues and organs (i.e., bone and cardiac tissues). Emerging as highly attractive cell-free, off-the-shelf nanotherapeutic agents for tissue regeneration, EVs are bilayered lipid membrane particles that are secreted by all living cells and play a critical role as cell-to-cell communicators through an exchange of EV cargos of protein, genetic materials, and other biological components. 3D bioprinting, combining 3D printing and biology, is a state-of-the-art additive manufacturing technology that uses computer-aided processes to enable simultaneous patterning of 3D cells and tissue constructs in bioinks. Although developing an effective system for targeted EVs delivery remains challenging, 3D bioprinting may offer a promising means to improve EVs delivery efficiency with controlled loading and release. The potential application of 3D bioprinted EVs to regenerate tissues has attracted attention over the past few years. As such, it is timely to explore the potential and associated challenges of utilizing 3D bioprinted EVs as a novel "cell-free" alternative regenerative medicine approach. In this review, we describe the biogenesis and composition of EVs, and the challenge of isolating and characterizing small EVs - sEVs (< 200 nm). Common 3D bioprinting techniques are outlined and the issue of bioink printability is explored. After applying the following search strategy in PubMed: "bioprinted exosomes" or "3D bioprinted extracellular vesicles", eight studies utilizing bioprinted EVs were found that have been included in this scoping review. Current studies utilizing bioprinted sEVs for various in vitro and in vivo tissue regeneration applications, including angiogenesis, osteogenesis, immunomodulation, chondrogenesis and myogenesis, are discussed. Finally, we explore the current challenges and provide an outlook on possible refinements for bioprinted sEVs applications.