Polyethylene glycol improves current methods for circulating extracellular vesicle-derived DNA isolation

Applications of plant-derived extracellular vesicles in medicine

Plant-derived extracellular vesicles (EVs) are promising therapeutic agents owing to their natural abundance, accessibility, and unique biological properties. This review provides a comprehensive exploration of the therapeutic potential of plant-derived EVs and emphasizes their anti-inflammatory, antimicrobial, and tumor-inhibitory effects. Here, we discussed the advancements in isolation and purification techniques, such as ultracentrifugation and size-exclusion chromatography, which are critical for maintaining the functional integrity of these nanovesicles. Next, we investigated the diverse administration routes of EVs and carefully weighed their respective advantages and challenges related to bioavailability and patient compliance. Moreover, we elucidated the multifaceted mechanisms of action of plant-derived EVs, including their roles in anti-inflammation, antioxidation, antitumor activity, and modulation of gut microbiota. We also discussed the impact of EVs on specific diseases such as cancer and inflammatory bowel disease, highlighting the importance of addressing current challenges related to production scalability, regulatory compliance, and immunogenicity. Finally, we proposed future research directions for optimizing EV extraction and developing targeted delivery systems. Through these efforts, we envision the seamless integration of plant-derived EVs into mainstream medicine, offering safe and potent therapeutic alternatives across various medical disciplines.

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.

Plant-derived exosome-like nanoparticles - from Laboratory to factory, a landscape of application, challenges and prospects

Recent decades have witnessed substantial interest in extracellular vesicles (EVs) due to their crucial role in intercellular communication across various biological processes. Among these, plant-derived exosome-like Nanoparticles (ELNs) have rapidly gained recognition as highly promising candidates. ELNs, characterized by diverse sources, cost-effective production, and straightforward isolation, present a viable option for preventing and treating numerous diseases. Furthermore, ELNs hold significant potential as carriers for natural or engineered drugs, enhancing their attractiveness and drawing considerable attention in science and medicine. However, translating ELNs into clinical applications poses several challenges. This study explores these challenges and offers critical insights into potential research directions. Additionally, it provides a forward-looking analysis of the industrial prospects for ELNs. With their broad applications and remarkable potential, ELNs stand at the forefront of biomedical innovation, poised to revolutionize disease management and drug delivery paradigms in the coming years.

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.

Most recent advances and applications of extracellular vesicles in tackling neurological challenges

Over the past few decades, there has been a notable increase in the global burden of central nervous system (CNS) diseases. Despite advances in technology and therapeutic options, neurological and neurodegenerative disorders persist as significant challenges in treatment and cure. Recently, there has been a remarkable surge of interest in extracellular vesicles (EVs) as pivotal mediators of intercellular communication. As carriers of molecular cargo, EVs demonstrate the ability to traverse the blood-brain barrier, enabling bidirectional communication. As a result, they have garnered attention as potential biomarkers and therapeutic agents, whether in their natural form or after being engineered for use in the CNS. This review article aims to provide a comprehensive introduction to EVs, encompassing various aspects such as their diverse isolation methods, characterization, handling, storage, and different routes for EV administration. Additionally, it underscores the recent advances in their potential applications in neurodegenerative disorder therapeutics. By exploring their unique capabilities, this study sheds light on the promising future of EVs in clinical research. It considers the inherent challenges and limitations of these emerging applications while incorporating the most recent updates in the field.

Development of new techniques and clinical applications of liquid biopsy in lung cancer management

Lung cancer is an exceedingly malignant tumor reported as having the highest morbidity and mortality of any cancer worldwide, thus posing a great threat to global health. Despite the growing demand for precision medicine, current methods for early clinical detection, treatment and prognosis monitoring in lung cancer are hampered by certain bottlenecks. Studies have found that during the formation and development of a tumor, molecular substances carrying tumor-related genetic information can be released into body fluids. Liquid biopsy (LB), a method for detecting these tumor-related markers in body fluids, maybe a way to make progress in these bottlenecks. In recent years, LB technology has undergone rapid advancements. Therefore, this review will provide information on technical updates to LB and its potential clinical applications, evaluate its effectiveness for specific applications, discuss the existing limitations of LB, and present a look forward to possible future clinical applications. Specifically, this paper will introduce technical updates from the prospectives of engineering breakthroughs in the detection of membrane-based LB biomarkers and other improvements in sequencing technology. Additionally, it will summarize the latest applications of liquid biopsy for the early detection, diagnosis, treatment, and prognosis of lung cancer. We will present the interconnectedness of clinical and laboratory issues and the interplay of technology and application in LB today.

Effect of the 35 nm and 70 nm Size Exclusion Chromatography (SEC) Column and Plasma Storage Time on Separated Extracellular Vesicles

The technical difficulty of separating extracellular vesicles (EVs) from plasma proteins in human blood presents a significant hurdle in EV research, particularly during nano ultra-high-performance liquid chromatography-tandem mass spectrometric (UHPLC-MS/MS) analysis, where detecting "vesicular" proteins among abundant plasma proteins is challenging. Standardisation is a pressing issue in EV research, prompting collaborative global efforts to address it. While the MISEV guidelines offer valuable recommendations, unanswered questions remain, particularly regarding sample storage. We compared size exclusion chromatography (SEC) columns with pore sizes of 35 nm and 70 nm to identify fractions with minimal contaminating proteins and the highest concentration of small EVs (sEVs). Following column selection, we explored potential differences in the quality and quantity of sEVs isolated from platelet-free plasma (PFP) after long-term storage at -80 °C (>2.5 years) compared to freshly drawn blood. Our methodologically rigorous study indicates that prolonged storage, under correct storage and processing conditions, does not compromise sEV quality. Both columns effectively isolated vesicles, with the 70 nm column exhibiting a higher abundance of "vesicular" proteins. We propose a relatively rapid and moderately efficient protocol for obtaining a comparatively pure sEV fraction from plasma, facilitating sEV processing in clinical trials.

Cell-specific extracellular vesicle-encapsulated exogenous GABA controls seizures in epilepsy

BACKGROUND

Epilepsy affects ∼60 million people worldwide. Most antiseizure medications in the market act on voltage-gated sodium or calcium channels, indirectly modulating neurotransmitter GABA or glutamate levels or multiple targets. Earlier studies made significant efforts to directly deliver GABA into the brain with varied success. Herein, we have hypothesized to directly deliver exogenous GABA to the brain with epilepsy through extracellular vesicles (EVs) from human GABA-producing cells and their progenitors as EVs largely mimic their parent cell composition.

METHODS

Human neural stem cells (NSCs), medial ganglionic eminence (MGE) cells, and GABAergic interneurons (INs) were generated from induced pluripotent stem cells (iPSCs) and characterized. EVs were isolated from NSCs, MGE cells, and INs and characterized for size and distribution, morphological features, and molecular markers. Exogenous GABA was passively loaded to the isolated EVs as a zwitterion at physiological pH, and the encapsulated dose of GABA was quantified. Epilepsy was developed through status epilepticus induction in Fisher rats by administration of repeated low doses of kainic acid. The extent of the seizures was measured for 10 h/ day for 3-6 months by video recording and its evaluation for stage III, IV and V seizures as per Racine scale. EVs from INs, MGE cells, and NSCs encapsulated with exogenous GABA were sequentially tested in the 4th, 5th, and 6th months by intranasal administration in the rats with epilepsy for detailed seizure, behavioral and synapse analysis. In separate experiments, several controls including exogenic GABA alone and EVs from INs and MGE cells were evaluated for seizure-controlling ability.

RESULTS

Exogenic GABA could enter the brain through EVs. Treatment with EVs from INs and MGE cells encapsulated with GABA significantly reduced total seizures, stage V seizures, and total time spent in seizure activity. EVs from NSCs encapsulated with GABA demonstrated limited seizure control. Exogenic GABA alone and EVs from INs and MGE cells individually failed to control seizures. Further, exogenic GABA with EVs from MGE cells improved depressive behavior while partially improving memory functions. Co-localization studies confirmed exogenous GABA with presynaptic vesicles in the hippocampus, indicating the interaction of exogenous GABA in the brain with epilepsy.

CONCLUSION

For the first time, the study demonstrated that exogenous GABA could be delivered to the brain through brain cell-derived EVs, which could regulate seizures in temporal lobe epilepsy. It is identified that the cellular origin of EVs plays a vital role in seizure control with exogenous GABA.

Extracellular Vesicle-Related Non-Coding RNAs in Hepatocellular Carcinoma: An Overview

Hepatocellular carcinoma (HCC) is the most common primary liver cancer. It is a major public health problem worldwide, and it is often diagnosed at advanced stages, when no effective treatment options are available. Extracellular vesicles (EVs) are nanosized double-layer lipid vesicles containing various biomolecule cargoes, such as lipids, proteins, and nucleic acids. EVs are released from nearly all types of cells and have been shown to play an important role in cell-to-cell communication. In recent years, many studies have investigated the role of EVs in cancer, including HCC. Emerging studies have shown that EVs play primary roles in the development and progression of cancer, modulating tumor growth and metastasis formation. Moreover, it has been observed that non-coding RNAs (ncRNAs) carried by tumor cell-derived EVs promote tumorigenesis, regulating the tumor microenvironment (TME) and playing critical roles in the progression, angiogenesis, metastasis, immune escape, and drug resistance of HCC. EV-related ncRNAs can provide information regarding disease status, thus encompassing a role as biomarkers. In this review, we discuss the main roles of ncRNAs present in HCC-derived EVs, including micro(mi) RNAs, long non-coding (lnc) RNAs, and circular (circ) RNAs, and their potential clinical value as biomarkers and therapeutic targets.

Extracellular vesicle biomarkers in ocular fluids associated with ophthalmic diseases

Extracellular vesicles (EVs) are released as highly stable lipid bilayer particles carrying proteins, lipids, glycans and miRNAs. The contents of EVs vary based on the cellular origin, biogenesis route and the functional state of the cell suggesting certain diseased conditions. A growing body of evidence show that EVs carry important molecules implicated in the development and progression of ophthalmic diseases. EVs associated with ophthalmic diseases are mainly carried by one of the three ocular biofluids which include tears, aqueous humor and vitreous humor. This review summarizes the list of EV derived biomarkers identified thus far in ocular fluids for ophthalmic disease diagnosis. Further, the methods used for sample collection, sample volume and the sample numbers used in these studies have been highlighted. Emphasis has been given to describe the EV isolation and the characterization methods used, EV size profiled and the EV concentrations analyzed by these studies, thus providing a roadmap for future EV biomarker studies in ocular fluids.

Combinatorial effect of calcium chloride and polyethylene glycol on efficient isolation of small extracellular vesicles

Small extracellular vesicles (sEVs) are cargo-carrying cellular nano-vesicles that have been explored for developing organic drug delivery modalities (DVM), an alternative to synthetic liposomes. However, scaled-up production of sEVs is a notable challenge in bringing sEV-based DVMs from the bench to the clinic. Ultracentrifugation is the most accepted isolation approach, but the cumbersome logistical issues and aftereffects of intense 'g' force hinder their applicability. In this study, we developed a new amenable isolation strategy for sEVs using a combinatorial treatment of calcium chloride and polyethylene glycol (PEG). An equivalent volume of cell culture medium from growing lung cancer A549 and H1299 cells was incubated overnight at 4 °C with different formulations (0.1 M CaCl2, 8% PEG, 12% PEG, 0.1 M CaCl2 + 8% PEG, and 0.1 M CaCl2 + 12% PEG) and centrifuged at 4000g to purify the precipitated sEVs as a pellet. Next, the extra CaCl2 was chelated out and the buffer was exchanged with PBS. The sEV number and protein content were assessed using the NTA (nanoparticle tracking analysis) and the BCA assay, respectively. Finally, transmission electron microscopy (TEM) was used to visualize the sEVs. The data from the present study demonstrated that the combination of 8% PEG and 0.1 M CaCl2 produced comparable numbers of sEVs with the ultracentrifugation technique. The sEV characteristics and structural integrity also remained intact, as evident from the TEM images and western blot assay. Thus, here we report an efficient technique for sEV isolation that can be easily scaled up.

Polyethylene Glycol -Mediated Exosome Isolation: A Method for Exosomal RNA Analysis

Background

: Exosomal RNAs (ExoRNAs) offer valuable insights into their cellular origin. ExoRNA studies were faced with challenges in obtaining sufficient amounts of high-quality RNA. Herein, we aimed to compare three traditional exosome isolation methods to introduce an appropriate strategy to extract RNA from cancer-derived exosomes for further RNA analysis.

Methods

Exosomes were isolated through ultracentrifugation, precipitation kit, and size exclusion column chromatography, and then characterized by dynamic light scattering and transmission electron microscopy, followed by extracting total RNA. The quality and quantity of the extracted RNAs were assessed by a NanoDrop and 2.5% agarose gel electrophoresis.

Results

Extracted exosomes displayed a similar range of size and morphology. We found that polyethylene glycol-precipitation method resulted in a higher RNA yield with a 260/280 ratio of 1.9. The obtained exoRNA appeared as a smear in the agarose gel, indicative of small exoRNAs.

Conclusion

We provide researchers a suitable approach to isolate exosomes based on yield and purity of exoRNA.

Exploring the Potential of Plant-Derived Exosome-like Nanovesicle as Functional Food Components for Human Health: A Review

Plant-derived exosome-like nanovesicles (PELNs) are bilayer membrane-enclosed nanovesicles secreted by plant cells, serving as carriers of various substances such as proteins, RNA, and metabolites. The mounting evidence suggests that PELN plays a crucial role in transmembrane signaling, nutrient transportation, apoptosis, and regulation of gut microbiota composition. This makes it a promising "dark nutrient" for plants to modulate human physiology and pathogenesis. A comprehensive understanding of PELN formation, uptake, and functional mechanisms can offer novel insights into plant nutrition and functional properties, thereby facilitating the precise development of plant-based foods and drugs. This article provides a summary of PELN extraction and characterization, as well as absorption and delivery processes. Furthermore, it focuses on the latest discoveries and underlying physiological mechanisms of PELN's functions while exploring future research directions.

Comparison of Three Methods to Extract Plasmodium falciparum DNA from Whole Blood and Dried Blood Spots

This study aimed to compare the effectiveness of three DNA extraction methods: the GF-1 Blood DNA Extraction Kit (GF-1 BD Kit), which employs a spin column along with lysing and washing buffers; the tris-ethylenediaminetetraacetic acid and proteinase K (TE-pK) method, which utilizes a combination of TE buffer and proteinase K for cell lysis; and DNAzol® Direct (DN 131), a single reagent combined with heating for the extraction process. Plasmodium falciparum DNA was extracted from both whole blood and dried blook spots (DBSs), with consideration of DNA concentration, purity, cost, time requirement, and limit of parasite detection (LOD) for each method. The target gene in this study was 18S rRNA, resulting in a 395-bp product using specific primers. In the comparative analysis, the DN 131 method yielded significantly higher DNA quantities from whole blood and DBSs than the GF-1 BD Kit and TE-pK methods. In addition, the DNA purity obtained from whole blood and DBSs using the GF-1 BD Kit significantly exceeded that obtained using the TE-pK and DN 131 methods. For LOD, the whole blood extracted using the DN 131, GF-1 BD Kit, and TE-pK methods revealed 0.012, 0.012, and 1.6 parasites/µL, respectively. In the case of DBSs, the LODs for the DN 131, GF-1 BD Kit, and TE-pK methods were 1.6, 8, and 200 parasites/µL, respectively. The results revealed that the TE-pK method was the most cost-effective, whereas the DN 131 method showed the simplest protocol. These findings offer alternative approaches for extracting Plasmodium DNA that are particularly well-suited for large-scale studies conducted in resource-limited settings.

High-yield and rapid isolation of extracellular vesicles by flocculation via orbital acoustic trapping: FLOAT

Extracellular vesicles (EVs) have been identified as promising biomarkers for the noninvasive diagnosis of various diseases. However, challenges in separating EVs from soluble proteins have resulted in variable EV recovery rates and low purities. Here, we report a high-yield ( > 90%) and rapid ( < 10 min) EV isolation method called FLocculation via Orbital Acoustic Trapping (FLOAT). The FLOAT approach utilizes an acoustofluidic droplet centrifuge to rotate and controllably heat liquid droplets. By adding a thermoresponsive polymer flocculant, nanoparticles as small as 20 nm can be rapidly and selectively concentrated at the center of the droplet. We demonstrate the ability of FLOAT to separate urinary EVs from the highly abundant Tamm-Horsfall protein, addressing a significant obstacle in the development of EV-based liquid biopsies. Due to its high-yield nature, FLOAT reduces biofluid starting volume requirements by a factor of 100 (from 20 mL to 200 µL), demonstrating its promising potential in point-of-care diagnostics.

Isolation of plant-derived exosome-like nanoparticles (PDENs) from Solanum nigrum L. berries and Their Effect on interleukin-6 expression as a potential anti-inflammatory agent

Inflammation is a temporary response of the immune system that can be treated using common anti-inflammatory drugs. However, prolonged use of these drugs increases the risk of adverse side effects. Accordingly, there is an increasing need for alternative treatments for inflammation with fewer side effects. Exosomes are extracellular vesicles secreted by most eukaryotic cells and have been studied as a candidate for cell-free therapy for inflammatory diseases due to their immunomodulatory and anti-inflammatory properties. In recent years, the focus of exosome research has shifted from animal cell-derived exosomes to plant-derived exosome-like nanoparticles (PDENs). Plant-derived exosome-like nanoparticles (PDENs) are easier to obtain, have minimal safety concerns, and can be produced in higher quantities and lower cost than exosomes derived from animal cells. In this study, the isolation and analysis of the anti-inflammatory potential of PDENs from black nightshade berries (Solanum nigrum L.) were carried out. The results of isolation and characterization showed that PDENs had a spherical morphology, measuring around 107 nm with zeta potential of -0.6 mV, and had a protein concentration of 275.38 μg/mL. PDENs were also shown to be internalized by RAW264.7 macrophage cell line after 2 hours of incubation and had no cytotoxicity effect up to the concentration of 2.5 μg/mL. Furthermore, exposure to several doses of PDENs to the LPS-stimulated RAW264.7 cell significantly decreased the expression of pro-inflammatory cytokine gene IL-6, as well as the expression of IL-6 protein up to 97,28%. GC-MS analysis showed the presence of neral, a monoterpene compound with known anti-inflammatory properties, which may contribute to the anti-inflammatory activity of PDENs isolated from Solanum nigrum L. berries. Taken together, the present study was the first to isolate and characterize PDENs from Solanum nigrum L. berries. The results of this study also demonstrated the anti-inflammatory activity of PDEN by suppressing the production of IL-6 in LPS-stimulated RAW264.7 cells.

A protocol for isolating and imaging large extracellular vesicles or midbody remnants from mammalian cell culture

Traditionally, midbody remnants (MBRs) are isolated from cell culture medium using ultracentrifugation, which is expensive and time consuming. Here, we present a protocol for isolating MBRs or large extracellular vesicles (EVs) from mammalian cell culture using either 1.5% polyethylene glycol 6000 (PEG6000) or PEG5000-coated gold nanoparticles. We describe steps for growing cells, collecting media, and precipitating MBRs and EVs from cell culture medium. We then detail characterization of MBRs through immunofluorescent antibody staining and immunofluorescent imaging.

Milk-derived small extracellular vesicles: a new perspective on dairy nutrition

Milk contains bioactive compounds that have multiple essential benefits. Milk-derived small extracellular vesicles (M-sEVs) have emerged as novel bioactive milk components with various beneficial biological functions and broad applications. The M-sEVs from different mammalian sources have similar composition and bioactive functions. The digestive stability and biocompatibility of the M-sEVs provide a good foundation for their physiological functions. Evidence suggests that M-sEVs promote intestinal, immune, bone, neural, liver, and heart health and show therapeutic effects against cancer, indicating their potential for use in functional foods. In addition, M-sEVs can be developed as natural delivery carriers owing to their superior structural characteristics. Further studies are needed to elucidate the relationship between the specific components and functions of M-sEVs, standardize their extraction processes, and refine relevant clinical trials to advance the future applications of M-sEVs. This review summarizes the structure and composition of M-sEVs isolated from different milk sources and discusses several common extraction methods. Since the introduction of M-sEVs for digestion and absorption, studies have been conducted on their biological functions. Furthermore, we outline the theoretical industrial production route, potential application scenarios of M-sEVs, and the future perspectives of M-sEV research.

Harnessing the therapeutic potential of mesenchymal stem cell-derived exosomes in cardiac arrest: Current advances and future perspectives

BACKGROUND

Cardiac arrest (CA), characterized by sudden onset and high mortality rates, is one of the leading causes of death globally, with a survival rate of approximately 6-24%. Studies suggest that the restoration of spontaneous circulation (ROSC) hardly improved the mortality rate and prognosis of patients diagnosed with CA, largely due to ischemia-reperfusion injury.

MAIN BODY

Mesenchymal stem cells (MSCs) exhibit self-renewal and strong potential for multilineage differentiation. Their effects are largely mediated by extracellular vesicles (EVs). Exosomes are the most extensively studied subgroup of EVs. EVs mainly mediate intercellular communication by transferring vesicular proteins, lipids, nucleic acids, and other substances to regulate multiple processes, such as cytokine production, cell proliferation, apoptosis, and metabolism. Thus, exosomes exhibit significant potential for therapeutic application in wound repair, tissue reconstruction, inflammatory reaction, and ischemic diseases.

CONCLUSION

Based on similar pathological mechanisms underlying post-cardiac arrest syndrome involving various tissues and organs in many diseases, the review summarizes the therapeutic effects of MSC-derived exosomes and explores the prospects for their application in the treatment of CA.

Current Knowledge and Future Perspectives of Exosomes as Nanocarriers in Diagnosis and Treatment of Diseases

Exosomes, as natural nanocarriers, characterized with low immunogenicity, non-cytotoxicity and targeted delivery capability, which have advantages over synthetic nanocarriers. Recently, exosomes have shown great potential as diagnostic markers for diseases and are also considered as a promising cell-free therapy. Engineered exosomes have significantly enhanced the efficacy and precision of delivering therapeutic agents, and are currently being extensively employed in targeted therapeutic investigations for various ailments, including oncology, inflammatory disorders, and degenerative conditions. Particularly, engineered exosomes enable therapeutic agent loading, targeted modification, evasion of MPS phagocytosis, intelligent control, and bioimaging, and have been developed as multifunctional nano-delivery platforms in recent years. The utilization of bioactive scaffolds that are loaded with exosome delivery has been shown to substantially augment retention, extend exosome release, and enhance efficacy. This approach has advanced from conventional hydrogels to nanocomposite hydrogels, nanofiber hydrogels, and 3D printing, resulting in superior physical and biological properties that effectively address the limitations of natural scaffolds. Additionally, plant-derived exosomes, which can participate in gut flora remodeling via oral administration, are considered as an ideal delivery platform for the treatment of intestinal diseases. Consequently, there is great interest in exosomes and exosomes as nanocarriers for therapeutic and diagnostic applications. This comprehensive review provides an overview of the biogenesis, composition, and isolation methods of exosomes. Additionally, it examines the pathological and diagnostic mechanisms of exosomes in various diseases, including tumors, degenerative disorders, and inflammatory conditions. Furthermore, this review highlights the significance of gut microbial-derived exosomes. Strategies and specific applications of engineered exosomes and bioactive scaffold-loaded exosome delivery are further summarized, especially some new techniques such as large-scale loading technique, macromolecular loading technique, development of multifunctional nano-delivery platforms and nano-scaffold-loaded exosome delivery. The potential benefits of using plant-derived exosomes for the treatment of gut-related diseases are also discussed. Additionally, the challenges, opportunities, and prospects of exosome-based nanocarriers for disease diagnosis and treatment are summarized from both preclinical and clinical viewpoints.

Extracellular vesicles: a rising star for therapeutics and drug delivery

Extracellular vesicles (EVs) are nano-sized, natural, cell-derived vesicles that contain the same nucleic acids, proteins, and lipids as their source cells. Thus, they can serve as natural carriers for therapeutic agents and drugs, and have many advantages over conventional nanocarriers, including their low immunogenicity, good biocompatibility, natural blood-brain barrier penetration, and capacity for gene delivery. This review first introduces the classification of EVs and then discusses several currently popular methods for isolating and purifying EVs, EVs-mediated drug delivery, and the functionalization of EVs as carriers. Thereby, it provides new avenues for the development of EVs-based therapeutic strategies in different fields of medicine. Finally, it highlights some challenges and future perspectives with regard to the clinical application of EVs.

Bioavailability of orally administered small extracellular vesicles from bovine milk in C57BL/6J mice

Small extracellular vesicles (sMEVs) from bovine milk are studied for delivering therapeutics. Here, we estimated sMEV bioavailability of an oral dose of sMEVs. Bovine sMEVs were labeled covalently with HiLyteTM 750 (MEV-750) and administered by oral gavage to C57BL/6J mice. Plasma, urine, feces, and tissues were harvested at timed intervals for up to 24 h and fluorescence was assessed. Fecal excretion amounted to approximately 55% of the oral MEV-750 dose in males and females. The levels of MEV-750 peaked in the intestinal mucosa and plasma approximately 6 h after oral gavage and returned to baseline at time point 24 h. MEV-750 were detectable in peripheral tissues approximately 12 h after gavage. MEV-750 excretion in urine peaked approximately 6 h after oral gavage and returned to background levels after 24 h. Analysis by size exclusion chromatography suggested that HiLyteTM detached from sMEVs in artificial gastric fluid but not in plasma, i.e., HiLyteTM allows to estimate sMEV bioavailability with comparably high confidence. We conclude that the apparent bioavailability of sMEVs is 45%, and sMEVs are transported to peripheral tissues in C57BL/6J mice; excretion in feces and urine are the main routes of sMEV elimination.

Exosomes: Nomenclature, Isolation, and Biological Roles in Liver Diseases

The biogenesis and biological roles of extracellular vesicles (EVs) in the progression of liver diseases have attracted considerable attention in recent years. EVs are membrane-bound nanosized vesicles found in different types of body fluids and contain various bioactive materials, including proteins, lipids, nucleic acids, and mitochondrial DNA. Based on their origin and biogenesis, EVs can be classified as apoptotic bodies, microvesicles, and exosomes. Among these, exosomes are the smallest EVs (30-150 nm in diameter), which play a significant role in cell-to-cell communication and epigenetic regulation. Moreover, exosomal content analysis can reveal the functional state of the parental cell. Therefore, exosomes can be applied to various purposes, including disease diagnosis and treatment, drug delivery, cell-free vaccines, and regenerative medicine. However, exosome-related research faces two major limitations: isolation of exosomes with high yield and purity and distinction of exosomes from other EVs (especially microvesicles). No standardized exosome isolation method has been established to date; however, various exosome isolation strategies have been proposed to investigate their biological roles. Exosome-mediated intercellular communications are known to be involved in alcoholic liver disease and nonalcoholic fatty liver disease development. Damaged hepatocytes or nonparenchymal cells release large numbers of exosomes that promote the progression of inflammation and fibrogenesis through interactions with neighboring cells. Exosomes are expected to provide insight on the progression of liver disease. Here, we review the biogenesis of exosomes, exosome isolation techniques, and biological roles of exosomes in alcoholic liver disease and nonalcoholic fatty liver disease.

Extracellular vesicles: Emerged as a promising strategy for regenerative medicine

Cell transplantation therapy has certain limitations including immune rejection and limited cell viability, which seriously hinder the transformation of stem cell-based tissue regeneration into clinical practice. Extracellular vesicles (EVs) not only possess the advantages of its derived cells, but also can avoid the risks of cell transplantation. EVs are intelligent and controllable biomaterials that can participate in a variety of physiological and pathological activities, tissue repair and regeneration by transmitting a variety of biological signals, showing great potential in cell-free tissue regeneration. In this review, we summarized the origins and characteristics of EVs, introduced the pivotal role of EVs in diverse tissues regeneration, discussed the underlying mechanisms, prospects, and challenges of EVs. We also pointed out the problems that need to be solved, application directions, and prospects of EVs in the future and shed new light on the novel cell-free strategy for using EVs in the field of regenerative medicine.

Exosomes and exosome-loaded scaffolds: Characterization and application in modern regenerative medicine

Exosomes (EXOs) are extracellular vesicles derived from the endosome. These heterogeneous nanoparticles (30-150 nm) are secreted from various cells and play important biological roles in intercellular communication. EXOs have received much attention for application in regenerative therapies and tissue repair due to their stability, biosafety, and functional versatility. However, in their free forms, "EXOs have poor bioavailability" at the site of action and are devoid of controlled-release mechanisms. These issues have been largely remedied by scaffolding EXOs with appropriate biomaterials such as hydrogels to create EXOs -loaded scaffold (ELS). These biomaterial-based scaffolds can be rationally designed and functionalized to enhance various aspects of ELS including bioavailability, biocompatibility, and loading/release control. Additionally, the ELS are superior to free EXOs due to reduced injection-related side effects. This review article provides a comprehensive and updated account of EXOs and ELS isolation, characterization, and application in regenerative medicine with a focus on soft tissue repair. We also offer insights into the advantages of ELS therapy compared to stem cell therapy towards application in wound healing, cardiac and bone repair. ELS promotes cell migration to the scaffold and will cause better homing of exosomes. Different types of scaffolds are made and each one can be modified based on the repair in the target tissues so that the reactions between the scaffold and exosome take place properly and effective signals are created for tissue repair.

Extracellular Vesicles as New Players in Drug Delivery: A Focus on Red Blood Cells-Derived EVs

The article is divided into several sections, focusing on extracellular vesicles' (EVs) nature, features, commonly employed methodologies and strategies for their isolation/preparation, and their characterization/visualization. This work aims to give an overview of advances in EVs' extensive nanomedical-drug delivery applications. Furthermore, considerations for EVs translation to clinical application are summarized here, before focusing the review on a special kind of extracellular vesicles, the ones derived from red blood cells (RBCEVs). Generally, employing EVs as drug carriers means managing entities with advantageous properties over synthetic vehicles or nanoparticles. Besides the fact that certain EVs also reveal intrinsic therapeutic characteristics, in regenerative medicine, EVs nanosize, lipidomic and proteomic profiles enable them to pass biologic barriers and display cell/tissue tropisms; indeed, EVs engineering can further optimize their organ targeting. In the second part of the review, we focus our attention on RBCEVs. First, we describe the biogenesis and composition of those naturally produced by red blood cells (RBCs) under physiological and pathological conditions. Afterwards, we discuss the current procedures to isolate and/or produce RBCEVs in the lab and to load a specific cargo for therapeutic exploitation. Finally, we disclose the most recent applications of RBCEVs at the in vitro and preclinical research level and their potential industrial exploitation. In conclusion, RBCEVs can be, in the near future, a very promising and versatile platform for several clinical applications and pharmaceutical exploitations.

Isolation and characterization of extracellular vesicles and future directions in diagnosis and therapy

Extracellular vesicles (EVs) are a unique and heterogeneous class of lipid bilayer nanoparticles secreted by most cells. EVs are regarded as important mediators of intercellular communication in both prokaryotic and eukaryotic cells due to their ability to transfer proteins, lipids and nucleic acids to recipient cells. In addition to their physiological role, EVs are recognized as modulators in pathological processes such as cancer, infectious diseases, and neurodegenerative disorders, providing new potential targets for diagnosis and therapeutic intervention. For a complete understanding of EVs as a universal cellular biological system and its translational applications, optimal techniques for their isolation and characterization are required. Here, we review recent progress in those techniques, from isolation methods to characterization techniques. With interest in therapeutic applications of EVs growing, we address fundamental points of EV-related cell biology, such as cellular uptake mechanisms and their biodistribution in tissues as well as challenges to their application as drug carriers or biomarkers for less invasive diagnosis or as immunogens. This article is categorized under: Diagnostic Tools > Biosensing Therapeutic Approaches and Drug Discovery > Nanomedicine for Oncologic Disease Therapeutic Approaches and Drug Discovery > Nanomedicine for Infectious Disease.

Small extracellular vesicle-loaded bevacizumab reduces the frequency of intravitreal injection required for diabetic retinopathy

Diabetic retinopathy (DR) is associated with retinal neovascularization, hard exudates, inflammation, oxidative stress and cell death, leading to vision loss. Anti-vascular endothelial growth factor (Anti-VEGF) therapy through repeated intravitreal injections is an established treatment for reducing VEGF levels in the retina for inhibiting neovascularization and leakage of hard exudates to prevent vision loss. Although anti-VEGF therapy has several clinical benefits, its monthly injection potentially causes devastating ocular complications, including trauma, intraocular hemorrhage, retinal detachment, endophthalmitis, etc. Methods: As mesenchymal stem cells (MSCs) and MSC-derived extracellular vesicles (MSC-EVs) demonstrated safety in clinical studies, we have tested the efficacy of MSC-derived small EVs (MSC-sEVs) loaded anti-VEGF drug bevacizumab in a rat model of DR. Results: The study identified a clinically significant finding that sEV loaded with bevacizumab reduces the frequency of intravitreal injection required for treating diabetic retinopathy. The sustained effect is observed from the reduced levels of VEGF, exudates and leukostasis for more than two months following intravitreal injection of sEV loaded with bevacizumab, while bevacizumab alone could maintain reduced levels for about one month. Furthermore, retinal cell death was consistently lower in this period than only bevacizumab. Conclusion: This study provided significant evidence for the prolonged benefits of sEVs as a drug delivery system. Also, EV-mediated drug delivery systems could be considered for clinical application of retinal diseases as they maintain vitreous clarity in the light path due to their composition being similar to cells.

Extracellular vesicles as source for the identification of minimally invasive molecular signatures in glioblastoma

The analysis of extracellular vesicles (EVs) as a source of cancer biomarkers is an emerging field since low-invasive biomarkers are highly demanded. EVs constitute a heterogeneous population of small membrane-contained vesicles that are present in most of body fluids. They are released by all cell types, including cancer cells and their cargo consists of nucleic acids, proteins and metabolites and varies depending on the biological-pathological state of the secretory cell. Therefore, EVs are considered as a potential source of reliable biomarkers for cancer. EV biomarkers in liquid biopsy can be a valuable tool to complement current medical technologies for cancer diagnosis, as their sampling is minimally invasive and can be repeated over time to monitor disease progression. In this review, we highlight the advances in EV biomarker research for cancer diagnosis, prognosis, and therapy monitoring. We especially focus on EV derived biomarkers for glioblastoma. The diagnosis and monitoring of glioblastoma still relies on imaging techniques, which are not sufficient to reflect the highly heterogenous and invasive nature of glioblastoma. Therefore, we discuss how the use of EV biomarkers could overcome the challenges faced in diagnosis and monitoring of glioblastoma.

Extracellular-Vesicle-Based Drug Delivery Systems for Enhanced Antitumor Therapies through Modulating the Cancer-Immunity Cycle

Although immunotherapy harnessing activity of the immune system against tumors has made great progress, the treatment efficacy remains limited in most cancers. Current anticancer immunotherapy is primarily based on T-cell-mediated cellular immunity, which highly relies on efficiency of triggering the cancer-immunity cycle, namely, tumor antigen release, antigen presentation by antigen presenting cells, T cell activation, recruitment and infiltration of T cells into tumors, and recognition and killing of tumor cells by T cells. Unfortunately, these immunotherapies are restricted by inefficient drug delivery and acting on only a single step of the cancer-immunity cycle. Due to high biocompatibility, low immunogenicity, intrinsic cell targeting, and easy chemical and genetic manipulation, extracellular vesicle (EV)-based drug delivery systems are widely used to amplify anticancer immune responses by serving as an integrated platform for multiple drugs or therapeutic strategies to synergistically activate several steps of cancer-immunity cycle. This review summarizes various mechanisms related to affecting cancer-immunity cycle disorders. Meanwhile, preparation and application of EV-based drug delivery systems in modulating cancer-immunity cycle are introduced, especially in the improvement of T cell recruitment and infiltration into tumors. Finally, opportunities and challenges of EV-based drug delivery systems in translational clinical applications are briefly discussed.

Optimizing Concentration of Polyethelene Glycol for Exosome Isolation from Plasma for Downstream Application

BACKGROUND

Exosomes are ubiquitous extracellular nanovesicles secreted from almost all living cells that are thought to be involved in several important cellular processes, including cell-cell communication and signaling. Exosomes serve as a liquid biopsy tool for clinical and translational research. Although many techniques have been used to isolate exosomes, including ultracentrigation, size-exclusion chromatography, and immunocapturing-based techniques, these techniques are not convenient, they require expensive instrumentation, and they are unhandy for clinical samples. Precipitation techniques from available commercial kits that contain polyethelene glycol (PEG) are now widely used, but these kits are expensive, especially if a large number of biological samples are to be processed.

OBJECTIVE

the purpose of this study is to compare and optimize the efficacy of different concentrations of PEG with two commercial kits ExoQuick (SBI) and Total Exosome Isolation (TEI) from Invitrogen in human plasma.

METHODS AND MATERIALS

we determined exosome quantity, size distribution, marker expression, and downstream application.

RESULTS

among the precipitation methods, we found the size of particles and concentrations with 10-20% PEG are similar to ExoQuick and better than TEI. Interestingly, we detected cfDNA with ExoQuick and 10-20% PEG but not TEI and 5% PEG. Moreover, 10% PEG detection of miR-122 and miR-16 expression was superior to ExoQuick and TEI. Furthermore, in proteomics results it also found the identified proteins better than commercial kits but there was a high level of contamination of other proteins in serum.

CONCLUSIONS

together, these findings show that an optimal concentration of 10% PEG serves as a guide for use with clinical samples in exosome isolation for downstream applications.

Organically derived exosomes as carriers of anticancer drugs and imaging agents for cancer treatment

Extracellular vesicles (EVs), is the umbrella term used for different types of vesicles produced by the cells, among which exosomes form the largest group. Exosomes perform intercellular communication by carrying several biologics from donor or parental cells and delivering them to recipient cells. Their unique cargo-carrying capacity has recently been explored for use as delivery vehicles of anticancer drugs and imaging agents. Being naturally produced, exosomes have many advantages over synthetic lipid-based nanoparticles currently being used clinically to treat cancer and other diseases. The finding of the role of exosomes in human diseases has led to numerous preclinical and clinical studies exploring their use as an amenable drug delivery vehicle and a theranostic in cancer diagnosis and treatment. However, there are certain limitations associated with exosomes, with the most important being the selection of the biological source for producing highly biocompatible exosomes on a large scale. This review article explores the various sources from which therapeutically viable exosomes can be isolated for use as drug carriers for cancer treatment. The methods of exosome isolation and the process of loading them with cancer therapeutics and imaging agents are also discussed in the follow-up sections. Finally, the article concludes with future directions for exosome-based applications in cancer diagnosis and treatment.

Assessment of microRNA profiles in small extracellular vesicles isolated from bovine colostrum with different immunoglobulin G concentrations

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The RNA concentration in sEV isolated from bovine colostrum was highest using the combination of the miRCURY Cell/Urine/CSF and miRNeasy Mini kits.

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The top 50 miRNA were the same using miRDeep2 and sRNAbench, predominated by let-7b, let-7a-5p, miR-30a-5p, and miR-148a.

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Predicted target genes of the top 50 miRNA regulate PI3K-Akt and MAPK signaling pathways, axon guidance, and focal adhesion.

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The abundance of miR-27a-3p was higher in colostrum with high IgG concentrations.

The consumption of bovine colostrum by newborn calves during the first days of life is essential to ensure the transfer of passive immunity. In addition to critical IgG, colostrum also contains non-IgG biomolecules, including microRNA (miRNA). The present study investigated the profiles of miRNA in small extracellular vesicles (sEV) isolated from bovine colostrum with high (256.5 ± 5.7 mg/mL, mean ± standard deviation, n = 4) and low (62.8 ± 3.6 mg/mL, n = 4) concentrations of IgG. Different combination of sEV extraction methods and bioinformatic pipelines (miRDeep2 and sRNAbench) for miRNA analysis were evaluated. Results showed that miRCURY exosome Cell/Urine/CSF and miRNeasy Mini kits yielded the highest RNA concentration. The miRNA-seq data analysis showed miRDeep2 yielded more comprehensive miRNAome compared with sRNAbench (527 versus 392 unique miRNA), whereas 389 shared miRNA were identified using both approaches. The profiles of top 50 miRNA were the same using both approaches, and their abundance contributed to 91.7% and 94.3% of total abundance of miRNA using miRDeep2 and sRNAbennch, respectively. These core miRNA were predicted to target 2,655 genes, which regulate 78 KEGG (Kyoto Encyclopedia of Genes and Genomes) level-3 pathways including PI3K-Akt and MAPK signaling pathway, axon guidance, and focal adhesion. The expression profiles of sEV-associated miRNA were similar between high- and low-IgG colostrum samples, despite the fact that the abundance of miR-27a-3p was higher in colostrum with high concentrations of IgG. In conclusion, a core miRNAome in bovine colostrum may play a role in regulating health and developmental stages in neonatal calves, independent of IgG concentration.

Comprehensive insight into endothelial progenitor cell-derived extracellular vesicles as a promising candidate for disease treatment

Endothelial progenitor cells (EPCs), which are a type of stem cell, have been found to have strong angiogenic and tissue repair capabilities. Extracellular vesicles (EVs) contain many effective components, such as cellular proteins, microRNAs, messenger RNAs, and long noncoding RNAs, and can be secreted by different cell types. The functions of EVs depend mainly on their parent cells. Many researchers have conducted functional studies of EPC-derived EVs (EPC-EVs) and showed that they exhibit therapeutic effects on many diseases, such as cardiovascular disease, acute kidney injury, acute lung injury, and sepsis. In this review article, we comprehensively summarized the biogenesis and functions of EPCs and EVs and the potent role of EPC-EVs in the treatment of various diseases. Furthermore, the current problems and future prospects have been discussed, and further studies are needed to compare the therapeutic effects of EVs derived from various stem cells, which will contribute to the accelerated translation of these applications in a clinical setting.

Principles and Problems of Exosome Isolation from Biological Fluids

Exosomes, the subclass of small membrane extracellular vesicles, have great diagnostic and therapeutic potential, but the lack of standardized methods for their efficient isolation and analysis limits the introduction of exosomal technologies into clinical practice. This review discusses the problems associated with the isolation of exosomes from biological fluids, as well as the principles of traditional and alternative methods of isolation. The aim of the presented review is to illustrate the variety of approaches based on the physical and biochemical properties of exosomes that can be used for exosome isolation. The advantages and disadvantages of different methods are discussed.

Exosomal RNAs: Novel Potential Biomarkers for Diseases-A Review

Exosomes are a subset of nano-sized extracellular vesicles originating from endosomes. Exosomes mediate cell-to-cell communication with their cargos, which includes mRNAs, miRNAs, lncRNAs, and circRNAs. Exosomal RNAs have cell specificity and reflect the conditions of their donor cells. Notably, their detection in biofluids can be used as a diagnostic marker for various diseases. Exosomal RNAs are ideal biomarkers because their surrounding membranes confer stability and they are detectable in almost all biofluids, which helps to reduce trauma and avoid invasive examinations. However, knowledge of exosomal biomarkers remains scarce. The present review summarizes the biogenesis, secretion, and uptake of exosomes, the current researches exploring exosomal mRNAs, miRNAs, lncRNAs, and circRNAs as potential biomarkers for the diagnosis of human diseases, as well as recent techniques of exosome isolation.

Isolation, Purification, and Characterization of Membrane Vesicles from Haloarchaea

Membrane vesicles (MVs), also described as extracellular vesicles (EVs), exosomes, or outer membrane vesicles (OMVs), are nano-sized (10-300 nm) spherical, membrane-bound structures deriving from the cell envelope. MVs have been studied extensively in both eukaryotic and prokaryotic systems, revealing a plethora of unique functions including cell-to-cell communication and protection of the cell. They are able to encapsulate specific cargos from nucleic acids to proteins, thereby concentrating cargo and providing protection from the extracellular environment. While MV production has been identified for all domains of life, with extensive investigation particularly for Bacteria and Eukaryota, it has only been studied in a few members of the archaeal domain, leaving a void of information concerning the role of MVs for the majority of Archaea. In addition, several discrepancies exist in the process of MV preparation and analysis between studies of MV production in different archaeal organisms. To further encourage the investigation of MVs in Archaea among the scientific community, we present a standardized method for the isolation, purification, and characterization of MVs based on the archaeal model organism, Haloferax volcanii. However, the described protocol can be applied to other Archaea with the appropriate modifications that are highlighted in Subheading 4.

Improving Isolation of Extracellular Vesicles by Utilizing Nanomaterials

Extracellular vesicles (EVs) as the new form of cellular communication have been demonstrated their potential use for disease diagnosis, prognosis and treatment. EVs are vesicles with a lipid bilayer and are present in various biofluids, such as blood, saliva and urine. Therefore, EVs have emerged as one of the most appealing sources for the discovery of clinical biomarkers. However, isolation of the target EVs from different biofluids is required for the use of EVs as diagnostic and therapeutic entities in clinical settings. Owing to their unique properties and versatile functionalities, nanomaterials have been widely investigated for EV isolation with the aim to provide rapid, simple, and efficient EV enrichment. Herein, this review presents the progress of nanomaterial-based isolations for EVs over the past five years (from 2017 to 2021) and discusses the use of nanomaterials for EV isolations based on the underlying mechanism in order to offer insights into the design of nanomaterials for EV isolations.

Technological Approaches in the Analysis of Extracellular Vesicle Nucleotide Sequences

Together with metabolites, proteins, and lipid components, the EV cargo consists of DNA and RNA nucleotide sequence species, which are part of the intracellular communication network regulating specific cellular processes and provoking distinct target cell responses. The extracellular vesicle (EV) nucleotide sequence cargo molecules are often investigated in association with a particular pathology and may provide an insight into the physiological and pathological processes in hard-to-access organs and tissues. The diversity and biological function of EV nucleotide sequences are distinct regarding EV subgroups and differ in tissue- and cell-released EVs. EV DNA is present mainly in apoptotic bodies, while there are different species of EV RNAs in all subgroups of EVs. A limited sample volume of unique human liquid biopsy provides a small amount of EVs with limited isolated DNA and RNA, which can be a challenging factor for EV nucleotide sequence analysis, while the additional difficulty is technical variability of molecular nucleotide detection. Every EV study is challenged with its first step of the EV isolation procedure, which determines the EV's purity, yield, and diameter range and has an impact on the EV's downstream analysis with a significant impact on the final result. The gold standard EV isolation procedure with ultracentrifugation provides a low output and not highly pure isolated EVs, while modern techniques increase EV's yield and purity. Different EV DNA and RNA detection techniques include the PCR procedure for nucleotide sequence replication of the molecules of interest, which can undergo a small-input EV DNA or RNA material. The nucleotide sequence detection approaches with their advantages and disadvantages should be considered to appropriately address the study problem and to extract specific EV nucleotide sequence information with the detection using qPCR or next-generation sequencing. Advanced next-generation sequencing techniques allow the detection of total EV genomic or transcriptomic data even at the single-molecule resolution and thus, offering a sensitive and accurate EV DNA or RNA biomarker detection. Additionally, with the processes where the EV genomic or transcriptomic data profiles are compared to identify characteristic EV differences in specific conditions, novel biomarkers could be discovered. Therefore, a suitable differential expression analysis is crucial to define the EV DNA or RNA differences between conditions under investigation. Further bioinformatics analysis can predict molecular cell targets and identify targeted and affected cellular pathways. The prediction target tools with functional studies are essential to help specify the role of the investigated EV-targeted nucleotide sequences in health and disease and support further development of EV-related therapeutics. This review will discuss the biological diversity of human liquid biopsy-obtained EV nucleotide sequences DNA and RNA species reported as potential biomarkers in health and disease and methodological principles of their detection, from human liquid biopsy EV isolation, EV nucleotide sequence extraction, techniques for their detection, and their cell target prediction.

[Extracellular vesicles: Definition, isolation and characterization]

Extracellular vesicles (EVs) originate from eukaryotic and prokaryotic cells and play a crucial role in intercellular communications. They are found in the environment of cells and tissues, and contribute to the complexity of different biological media, in particular biofluids. Due to their high diversity of cell origin, size range, concentration and composition, EVs offer some of the most important challenges in (pre-)analytical fields. To tackle these challenges, many works deal with the development and implementation of a wide variety of approaches, technologies and methodologies to enrich, isolate, quantify and characterize EVs and their subsets. Nevertheless, other components such as lipoproteins or viruses in complex samples, can interfere with EVs qualification, and make difficult, even today, to standardize biochemical and physical approaches for this purpose. The present chapter presents EVs and the mostly used technics for their isolation and characterization. Performances of methods in terms of resolution, discrimination, throughput and also ability to be or not applied in clinics, are also discussed.

Methylation Markers in Cutaneous Melanoma: Unravelling the Potential Utility of Their Tracking by Liquid Biopsy

Malignant melanoma is the most serious, life-threatening form of all dermatologic diseases, with a poor prognosis in the presence of metastases and advanced disease. Despite recent advances in targeted therapy and immunotherapy, there is still a critical need for a better understanding of the fundamental mechanisms behind melanoma progression and resistance onset. Recent advances in genome-wide methylation methods have revealed that aberrant changes in the pattern of DNA methylation play an important role in many aspects of cancer progression, including cell proliferation and migration, evasion of cell death, invasion, and metastasization. The purpose of the current review was to gather evidence regarding the usefulness of DNA methylation tracking in liquid biopsy as a potential biomarker in melanoma. We investigated the key genes and signal transduction pathways that have been found to be altered epigenetically in melanoma. We then highlighted the circulating tumor components present in blood, including circulating melanoma cells (CMC), circulating tumor DNA (ctDNA), and tumor-derived extracellular vesicles (EVs), as a valuable source for identifying relevant aberrations in DNA methylation. Finally, we focused on DNA methylation signatures as a marker for tracking response to therapy and resistance, thus facilitating personalized medicine and decision-making in the treatment of melanoma patients.

A scalable coaxial bioprinting technology for mesenchymal stem cell microfiber fabrication and high extracellular vesicle yield

Mesenchymal stem cell (MSC)-derived extracellular vesicles (EVs) are promising candidates for regenerative medicine; however, the lack of scalable methods for high quantity EV production limits their application. In addition, signature EV-derived proteins shared in 3D environments and 2D surfaces, remain mostly unknown. Herein, we present a platform combining MSC microfiber culture with ultracentrifugation purification for high EV yield. Within this platform, a high quantity MSC solution (∼3 × 10⁸total cells) is encapsulated in a meter-long hollow hydrogel-microfiber via coaxial bioprinting technology. In this 3D core-shell microfiber environment, MSCs express higher levels of stemness markers (Oct4, Nanog, Sox2) than in 2D culture, and maintain their differentiation capacity. Moreover, this platform enriches particles by ∼1009-fold compared to conventional 2D culture, while preserving their pro-angiogenic properties. Liquid chromatography-mass spectrometry characterization results demonstrate that EVs derived from our platform and conventional 2D culturing have unique protein profiles with 3D-EVs having a greater variety of proteins (1023 vs 605), however, they also share certain proteins (536) and signature MSC-EV proteins (10). This platform, therefore, provides a new tool for EV production using microfibers in one culture dish, thereby reducing space, labor, time, and cost.

A method of separating extracellular vesicles from blood shows potential clinical translation, and reveals extracellular vesicle cargo gremlin-1 as a diagnostic biomarker

Extracellular vesicles (EVs) have potential as minimally invasive biomarkers. However, the methods most commonly used for EV retrieval rely on ultracentrifugation, are time-consuming, and unrealistic to translate to standard-of-care. We sought a method suitable for EV separation from blood that could be used in patient care. Sera from breast cancer patients and age-matched controls (n = 27 patients; n = 36 controls) were analysed to compare 6 proposed EV separation methods. The EVs were then characterised on 8 parameters. The selected method was subsequently applied to independent cohorts of sera (n = 20 patients; n = 20 controls), as proof-of-principle, investigating EVs' gremlin-1 cargo. Three independent runs with each method were very reproducible, within each given method. All isolates contained EVs, although they varied in quantity and purity. Methods that require ultracentrifugation were not superior for low volumes of sera typically available in routine standard-of-care. A CD63/CD81/CD9-coated immunobead-based method was most suitable based on EV markers' detection and minimal albumin and lipoprotein contamination. Applying this method to independent sera cohorts, EVs and their gremlin-1 cargo were at significantly higher amounts for breast cancer patients compared to controls. In conclusion, CD63/CD81/CD9-coated immunobeads may enable clinical utility of blood-based EVs as biomarkers.

Small extracellular vesicles in cancer

Extracellular vesicles (EV) are lipid-bilayer enclosed vesicles in submicron size that are released from cells. A variety of molecules, including proteins, DNA fragments, RNAs, lipids, and metabolites can be selectively encapsulated into EVs and delivered to nearby and distant recipient cells. In tumors, through such intercellular communication, EVs can regulate initiation, growth, metastasis and invasion of tumors. Recent studies have found that EVs exhibit specific expression patterns which mimic the parental cell, providing a fingerprint for early cancer diagnosis and prognosis as well as monitoring responses to treatment. Accordingly, various EV isolation and detection technologies have been developed for research and diagnostic purposes. Moreover, natural and engineered EVs have also been used as drug delivery nanocarriers, cancer vaccines, cell surface modulators, therapeutic agents and therapeutic targets. Overall, EVs are under intense investigation as they hold promise for pathophysiological and translational discoveries. This comprehensive review examines the latest EV research trends over the last five years, encompassing their roles in cancer pathophysiology, diagnostics and therapeutics. This review aims to examine the full spectrum of tumor-EV studies and provide a comprehensive foundation to enhance the field. The topics which are discussed and scrutinized in this review encompass isolation techniques and how these issues need to be overcome for EV-based diagnostics, EVs and their roles in cancer biology, biomarkers for diagnosis and monitoring, EVs as vaccines, therapeutic targets, and EVs as drug delivery systems. We will also examine the challenges involved in EV research and promote a framework for catalyzing scientific discovery and innovation for tumor-EV-focused research.

Rapid Capture of Cancer Extracellular Vesicles by Lipid Patch Microarrays

Extracellular vesicles (EVs) contain various bioactive molecules such as DNA, RNA, and proteins, and play a key role in the regulation of cancer progression. Furthermore, cancer-associated EVs carry specific biomarkers and can be used in liquid biopsy for cancer detection. However, it is still technically challenging and time consuming to detect or isolate cancer-associated EVs from complex biofluids (e.g., blood). Here, a novel EV-capture strategy based on dip-pen nanolithography generated microarrays of supported lipid membranes is presented. These arrays carry specific antibodies recognizing EV- and cancer-specific surface biomarkers, enabling highly selective and efficient capture. Importantly, it is shown that the nucleic acid cargo of captured EVs is retained on the lipid array, providing the potential for downstream analysis. Finally, the feasibility of EV capture from patient sera is demonstrated. The demonstrated platform offers rapid capture, high specificity, and sensitivity, with only a small need in analyte volume and without additional purification steps. The platform is applied in context of cancer-associated EVs, but it can easily be adapted to other diagnostic EV targets by use of corresponding antibodies.

Evidence for the Need to Evaluate More Than One Source of Extracellular Vesicles, Rather Than Single or Pooled Samples Only, When Comparing Extracellular Vesicles Separation Methods

Simple Summary

Extracellular vesicles (EVs) are packages of information released from cells and are often described as mini maps of their cells of origin. EVs have many uses. For example, those found in the blood of cancer patients may inform us about tumor growth, spread, immune suppression, and drug response/resistance. EVs from other sources, inducing certain types of cells grown under laboratory conditions, have potential as therapeutics and drug delivery vehicles. For this reason, a few studies have compared methods of collecting EVs, but typically using only one EV source for the comparison. We had concerns that testing one source and extrapolating to others may not be adequate. To test this, we selected three HER2-positive breast cancer cell lines that grow in exactly the same type of fluid. We collected the fluid and tested two ways of separating the EVs from the fluid. We studied them based on seven characteristics. Both EV separation methods provided reproducible results for any of the given cell lines. However, the characteristics of the EV isolates were cell line- and method-dependent. Thus, we recommend not relying on a single EV source when comparing and selecting separation techniques for fundamental research or exploitation for clinical utility.

Abstract

To study and exploit extracellular vesicles (EVs) for clinical benefit as biomarkers, therapeutics, or drug delivery vehicles in diseases such as cancer, typically we need to separate them from the biofluid into which they have been released by their cells of origin. For cultured cells, this fluid is conditioned medium (CM). Previous studies comparing EV separation approaches have typically focused on CM from one cell line or pooled samples of other biofluids. We hypothesize that this is inadequate and that extrapolating from a single source of EVs may not be informative. Thus, in our study of methods not previous compared (i.e., the original differential ultracentrifugation (dUC) method and a PEG followed by ultracentrifugation (PEG + UC) method), we analyzed CM from three different HER2-positive breast cancer cell lines (SKBR3, EFM192A, HCC1954) that grow in the same culture medium type. CM from each was collected and equally divided between both protocols. The resulting isolates were compared on seven characteristics/parameters including particle size, concentration, structure/morphology, protein content, purity, detection of five EV markers, and presence of HER2. Both dUC and PEG + UC generated reproducible data for any given breast cancer cell lines’ CM. However, the seven characteristics of the EV isolates were cell line- and method-dependent. This suggests the need to include more than one EV source, rather than a single or pooled sample, when selecting an EV separation method to be advanced for either research or clinical purposes.

Characteristics and Clinical Application of Extracellular Vesicle-Derived DNA

Extracellular vesicles (EVs) carry RNA, proteins, lipids, and diverse biomolecules for intercellular communication. Recent studies have reported that EVs contain double-stranded DNA (dsDNA) and oncogenic mutant DNA. The advantage of EV-derived DNA (EV DNA) over cell-free DNA (cfDNA) is the stability achieved through the encapsulation in the lipid bilayer of EVs, which protects EV DNA from degradation by external factors. The existence of DNA and its stability make EVs a useful source of biomarkers. However, fundamental research on EV DNA remains limited, and many aspects of EV DNA are poorly understood. This review examines the known characteristics of EV DNA, biogenesis of DNA-containing EVs, methylation, and next-generation sequencing (NGS) analysis using EV DNA for biomarker detection. On the basis of this knowledge, this review explores how EV DNA can be incorporated into diagnosis and prognosis in clinical settings, as well as gene transfer of EV DNA and its therapeutic potential.

High-grade extracellular vesicles preparation by combined size-exclusion and affinity chromatography

Extracellular vesicles (EVs) have recently gained growing interest for their diagnostic and therapeutic potential. Despite this, few protocols have been reported for the isolation of EVs with preserved biological function. Most EV purification methods include a precipitation step that results in aggregation of vesicles and most available techniques do not efficiently separate the various types of EVs such as exosomes and ectosomes, which are involved in distinct biological processes. For this reason, we developed a new two-step fast performance liquid chromatography (FPLC) protocol for purification of large numbers of EVs. The method comprises size exclusion chromatography followed by immobilized metal affinity chromatography, which is enabled by expression of poly-histidine tagged folate receptor α in the parental cells. Characterisation and comparison of the EVs obtained by this method to EVs purified by differential centrifugation, currently the most common method to isolate EVs, demonstrated higher purity and more selective enrichment of exosomes in EV preparations using our FPLC method, as assessed by comparison of marker proteins and density distribution. Our studies reveal new possibilities for the isolation of defined subpopulations of EVs with preserved biological function that can easily be upscaled for production of larger amounts of EVs.

In-air particle generation by on-chip electrohydrodynamics

Electrohydrodynamic atomization has been emerging as a powerful approach for respiratory treatment, including the generation and delivery of micro/nanoparticles as carriers for drugs and antigens. In this work, we present a new conceptual design in which two nozzles facilitate dual electrospray coexisting with ionic wind at chamfered tips by a direct current power source. Experimental results by a prototype have demonstrated the capability of simultaneously generating-and-delivering a stream of charged reduced particles. The concept can be beneficial to pulmonary nano-medicine delivery since the mist of nanoparticles is migrated without any restriction of either the collector or the assistance of external flow, but is pretty simple in designing and manufacturing devices.