Size and shape characterization of hydrated and desiccated exosomes

A novel hydrogel loaded with plant exosomes and stem cell exosomes as a new strategy for treating diabetic wounds

Diabetic wound healing is constrained by various factors, including chronic inflammation, sustained oxidative stress, impaired angiogenesis, and abnormal wound microenvironments. Exosomes derived from mesenchymal stem cells (MSC-exo) contain a wealth of bioactive substances that play a positive role in promoting diabetic wound healing. Plant-derived exosomes, as a novel therapeutic approach, are continuously being explored. Momordica charantia (MC) has been shown to possess blood glucose-lowering effects, and its exosomes are of significant relevance for treating diabetic wounds. However, direct application of exosomes to wounds faces challenges such as poor stability and short retention time, limiting their therapeutic effectiveness and clinical applicability. Encapsulating exosomes in hydrogels is an effective strategy to preserve their bioactivity. In this study, we fabricated a hydrogel loaded with MSC-exo and MC exosomes (MC-exo) by photopolymerization of methacrylated gelatin (GelMA) and dopamine (MEMC-Gel). The resulting MEMC-Gel exhibited favorable mechanical properties, adhesion, degradability, absorbency, and biocompatibility. In vitro, MEMC-Gel demonstrated the ability to resist inflammation, counter oxidative stress, promote fibroblast migration, support endothelial cell angiogenesis, and regulate macrophage polarization. In a diabetic mouse wound model, MEMC-Gel accelerated wound healing by inhibiting inflammation and oxidative stress, modulating macrophage immune responses and hyperglycemia within the microenvironment, promoting angiogenesis, and enhancing epithelialization. In conclusion, MEMC-Gel is an outstanding hydrogel dressing that synergistically promotes repair by loading MSC-exo and MC-exo, significantly accelerating diabetic wound healing through multiple mechanisms. This multifunctional hydrogel, based on exosomes from two different sources, provides an innovative therapeutic strategy for diabetic wound repair with broad clinical application potential.

Multiparametric functional characterization of individual lipid nanoparticles using surface-sensitive light-scattering microscopy

The most efficient lipid nanoparticles (LNPs) for gene therapeutics rely on specific lipids that protect the oligonucleotide cargo and aid cellular uptake and subsequent endosomal escape. Yet, the efficacy of current state-of-the-art LNP formulations remains low, a few percent at best. A deeper understanding of how LNP cargo, lipid composition, stoichiometry, size, structure, and pH-induced conformational changes influence their efficiency is therefore necessary for improved design. Given the variability of these properties, preferred screening methods should offer single-particle-resolved multiparametric characterization. In this work, we employ combined surface-sensitive fluorescence and label-free scattering microscopy with single LNP resolution, which when integrated with microfluidics for liquid exchange between media of varying refractive index, enables quantification of LNP size, refractive index, and cargo content. We investigate two LNP formulations that, while similar in size and mRNA content, exhibit differences in functional mRNA delivery. Correlating size with the content of Cy5-labeled mRNA revealed that the cargo scaled with LNP volume for both types of LNPs, while the refractive index varied marginally across LNP size. While this multiparametric fingerprinting alone could not distinguish the two LNP formulations, we use the same experimental platform to show that their difference in fusogenicity to a supporting lipid bilayer under early endosomal conditions (drop in pH from 7.4 to 6.0) correlates with observed differences in in vitro cellular data. This highlights a limitation of the current state-of-the-art toolbox for in situ LNP characterization, which generally focuses on structural properties of suspended LNPs, which may not adequately capture functional performance.

Comparison of Methods for Isolating Exosomes from Plasma Subjects with Normal and High Fat Percentages

Adipose tissue is responsible for fat storage and is an important producer of extracellular vesicles (EVs). The biological content of exosomes, one kind of EV, provides information on aspects such as immunometabolic alterations. This study aimed to compare three plasma exosome isolation methods-using a commercial kit (CK), size exclusion chromatography (SEC), and differential centrifugation (DC)-and select the best one. Individuals categorized by normal and high body fat percentages were used. The DC and CK were proven to be the most advantageous out of the exosome isolation methods, so we suggest these methods for further protein and molecular analyses, respectively. Still, we emphasize the importance of selecting an appropriate methodology depending on the specific research objectives. At the same time, no statistical differences in exosome quality, morphology, total protein, or microRNA concentration were observed between individuals categorized by body fat percentage, so we suggest that the exosomal cargo varies in individuals with normal and high fat percentages.

Scalable production of anti-inflammatory exosomes from three-dimensional cultures of canine adipose-derived mesenchymal stem cells: production, stability, bioactivity, and safety assessment

BACKGROUND

The therapeutic potential of exosomes derived from mesenchymal stem cells (MSCs) is increasingly recognized in veterinary medicine. This study explored the feasibility of a microcarrier-based three-dimensional (3D) culture system for producing the exosomes (cEXO). Investigations were conducted to enhance production efficiency, ensure stability, and evaluate the therapeutic potential of cEXO for anti-inflammatory applications while assessing their safety profile.

RESULTS

The microcarrier-based 3D culture system improved efficient production of cEXO, yielding exosomes with acceptable profiles, including a size of approximately 81.22 nm, negative surface charge, and high particle concentration (1.32 × 109 particles/mL). Confocal imaging proved dynamic changes in cell viability across culture phases, highlighting the challenges of maintaining cell viability during repeated exosome collection cycles. Characterization via transmission electron microscopy, nanoparticle tracking analysis, and zeta-potential measurements confirmed the stability and functionality of cEXO, particularly when stored at -20 °C. Functional assays showed that cEXO exerted significant anti-inflammatory activity in RAW264.7 macrophages in an inverse dose-dependent manner, with no observed cytotoxicity to fibroblasts or macrophages. Acute toxicity testing in rats revealed no adverse effects on clinical parameters, organ health, or body weight, supporting the safety of cEXO for therapeutic use.

CONCLUSIONS

This study highlights the potential of a microcarrier-based 3D culture system for scalable cEXO production with robust anti-inflammatory activity, stability, and safety profiles. These findings advance the development of cEXO-based therapies and support their application in veterinary regenerative medicine.

Human breast milk-derived exosomes attenuate lipopolysaccharide-induced activation in microglia

Microglia mediate the immune response in the central nervous system to many insults, including lipopolysaccharide (LPS), a bacterial endotoxin that initiates neuroinflammation in the neonatal population, especially preterm infants. The synthesis of the proinflammatory proteins CD40 and NLRP3 depends on the canonical NF-κB cascade as the genes encoding CD40 and NLRP3 are transcribed by the phosphorylated NF-κB p50/p65 heterodimer in LPS-induced microglia. Exosomes, which are nanosized vesicles (40-150 nm) involved in intercellular communication, are implicated in many pathophysiological processes. Human breast milk, which is rich in exosomes, plays a vital role in neonatal immune system maturation and adaptation. Activated microglia may cause brain-associated injuries or disorders; therefore, we hypothesize that human breast milk-derived exosomes (HBME) attenuate LPS-induced activation of CD40 and NLRP3 by decreasing p38 MAPK and NF-κB p50/p65 activation/phosphorylation downstream of TLR4 in murine microglia (BV2). Human microglia (HMC3) showed a significant decrease in p65 phosphorylation. We isolated purified HBME and characterized them using nanoparticle tracking analysis, transmission electron microscopy, fluorescence-activated cell sorting, and western blots. Analysis of microglia exposed to LPS and HBME indicated that HBME modulated the expression of signaling molecules in the canonical NF-κB pathway, including MyD88, IκBα, p38 MAPK, NF-κB p65, and their products CD40, NLRP3, and cytokines IL-1β and IL-10. Thus, HBMEs have great potential for attenuating the microglial response to LPS.

Plant-Derived Exosome-like Nanoparticles: A Comprehensive Overview of Their Composition, Biogenesis, Isolation, and Biological Applications

Plant-derived exosome-like nanoparticles (PELNs) are a type of membranous vesicle isolated from plant tissues. They contain proteins, lipids, nucleic acids, and other components. PELNs are involved in the defensive response to pathogen attacks by exerting anti-inflammatory, antiviral, antifibrotic, and antitumor effects through the substances they contain. Most PELNs are edible and can be used as carriers for delivering specific drugs without toxicity and side effects, making them a hot topic of research. Sources of PELNs are abundantly, and they can be produced in high yields, with a low risk of developing immunogenicity in vivo. This paper summarizes the formation, isolation, and purification methods; physical properties; and composition of PELNs through a comprehensive literature search. It also analyzes the biomedical applications of PELNs, as well as future research directions. This paper provides new ideas and methods for future research on PELNs.

Exploring the manganese-dependent interaction between a transcription factor and its corresponding DNA: insights from gas-phase electrophoresis on a nES GEMMA instrument

Manganese ion homeostasis is vital for bacteria and is achieved via manganese-dependent transcription factors. Manganese mediation of transcription factor attachment to the corresponding oligonucleotide sequences can be investigated, e.g. via electrophoretic mobility shift assays (EMSA). Formation of specific biocomplexes leads to differences in the migration pattern upon gel electrophoresis. Focusing on electrophoresis in the gas-phase, applying a nano electrospray gas-phase electrophoretic mobility molecular analyzer (nES GEMMA) also known as nES differential mobility analyzer (nES DMA), and on transcription factors (MntR proteins) from Bacillus subtilis and Mycobacterium tuberculosis, we took interest in the gas-phase electrophoresis of the corresponding biospecific complexes. We compared nES GEMMA, separating analytes in the nanometer regime (a few to several hundred nm in diameter) in the gas-phase in their native state according to particle size, to EMSA data. Indeed we were able to demonstrate manganese-mediated attachment of MntR to target genomic sequences with both analytical techniques. Despite some inherent pitfalls of the nES GEMMA method like analyte/instrument surface interactions, we were able to detect the target complexes. Moreover, we were able to calculate the molecular weight (MW) of the obtained species by application of a correlation function based on nES GEMMA obtained data. As gas-phase electrophoresis also offers the possibility of offline hyphenation to orthogonal analysis techniques, we are confident that nES GEMMA measurements are not just complementary to EMSA, but will offer the possibility of further in-depth characterization of biocomplexes in the future.

Exosomal transcript cargo and functional correlation with HNSCC patients' survival

BACKGROUND

HPV status in a subset of HNSCC is linked with distinct treatment outcomes. Present investigation aims to elucidate the distinct clinicopathological features of HPV-positive and HPV-negative HNSCC and investigate their association with the HNSCC patient survival.

MATERIALS AND METHODS

The total RNA of exosomes from HPV-positive (93VU147T) and HPV-negative (OCT-1) HNSCC cells was isolated, and the transcripts were estimated using Illumina HiSeq X. The expression of altered transcripts and their clinical relevance were further analyzed using publicly available cancer transcriptome data from The Cancer Genome Atlas (TCGA).

RESULTS

Transcriptomic analyses identified 3785 differentially exported transcripts (DETs) in HPV-positive exosomes compared to HPV-negative exosomes. DETs that regulate the protein machinery, cellular redox potential, and various neurological disorder-related pathways were over-represented in HPV-positive exosomes. TCGA database revealed the clinical relevance of altered transcripts. Among commonly exported abundant transcripts, SGK1 and MAD1L1 showed high expression, which has been correlated with poor survival in HNSCC patients. In the top 20 DETs of HPV-negative exosomes, high expression of FADS3, SGK3, and TESK2 correlated with poor survival of the HNSCC patients in the TCGA database.

CONCLUSION

Overall, our study demonstrates that HPV-positive and HPV-negative cells' exosomes carried differential transcripts cargo that may be related to pathways associated with neurological disorders. Additionally, the altered transcripts identified have clinical relevance, correlating with patient survival in HNSCC, thereby highlighting their potential as biomarkers and as therapeutic targets.

Stem cell-derived exosomes as a potential therapy for schistosomal hepatic fibrosis in experimental animals

Schistosomiasis is a neglected tropical disease. Egg-induced granuloma formation and tissue fibrosis are the main causes of the high morbidity and mortality of schistosomiasis. Mesenchymal stem cells (MSCs)-derived exosomes play an important role with a superior safety profile than MSCs in the treatment of liver fibrosis. Therefore, the aim of this study was to investigate the potential therapeutic effect of MSCs-derived exosomes on schistosomal hepatic fibrosis. Exosomes were isolated from bone marrow MSCs and characterized. A total of 85 mice were divided into four groups: group I (control group), group II (PZQ group) infected and treated with PZQ, group III (EXO group) infected and treated with MSCs-derived exosomes and group IV (PZQ+EXO group) infected and treated with both PZQ and MSCs-derived exosomes. Assessment of treatment efficacy was evaluated by histopathological and immunohistochemical examination of liver sections by proliferating cell nuclear antigen (PCNA) and nuclear factor-κB (NF-κB). The results showed significant reduction of the number and diameter of hepatic granulomas, hepatic fibrosis, upregulation of PCNA expression and reduction of NF-κB expression in EXO and PZQ+EXO groups as compared to other groups at all durations post infection. Additionally, more improvement was observed in PZQ+EXO group. In conclusion, MSCs-derived exosomes are a promising agent for the treatment of schistosomal hepatic fibrosis, and their combination with PZQ shows a synergistic action including antifibrotic and anti-inflammatory effects. However, further studies are required to establish their functional components and their mechanisms of action.

Biomechanics of circulating cellular and subcellular bioparticles: beyond separation

Biomechanical attributes have emerged as novel markers, providing a reliable means to characterize cellular and subcellular fractions. Numerous studies have identified correlations between these factors and patients' medical status. However, the absence of a thorough overview impedes their applicability in contemporary state-of-the-art therapeutic strategies. In this context, we provide a comprehensive analysis of the dimensions, configuration, rigidity, density, and electrical characteristics of normal and abnormal circulating cells. Subsequently, the discussion broadens to encompass subcellular bioparticles, such as extracellular vesicles (EVs) enriched either from blood cells or other tissues. Notably, cell sizes vary significantly, from 2 μm for platelets to 25 μm for circulating tumor cells (CTCs), enabling the development of size-based separation techniques, such as microfiltration, for specific diagnostic and therapeutic applications. Although cellular density is relatively constant among different circulating bioparticles, it allows for reliable density gradient centrifugation to isolate cells without altering their native state. Additionally, variations in EV surface charges (-6.3 to -45 mV) offer opportunities for electrophoretic and electrostatic separation methods. The distinctive mechanical properties of abnormal cells, compared to their normal counterparts, present an exceptional opportunity for diverse medical and biotechnological approaches. This review also aims to provide a holistic view of the current understanding of popular techniques in this domain that transcend conventional boundaries, focusing on early harvesting of malignant cells from body fluids, designing effective therapeutic options, cell targeting, and resonating with tissue and genetic engineering principles.

Exosomes in asthma: Underappreciated contributors to the pathogenesis and novel therapeutic tools

OBJECTIVE

Asthma, a chronic inflammatory disease with diverse pathomechanisms, presents challenges in developing personalized diagnostic and therapeutic approaches. This review aims to provide a comprehensive overview of the role of exosomes, small extracellular vesicles, in asthma pathophysiology and explores their potential as diagnostic biomarkers and therapeutic tools.

METHODS

A literature search was conducted to identify recent studies investigating the involvement of exosomes in asthma. The retrieved articles were analyzed to extract relevant information on the role of exosomes in maintaining lung microenvironment homeostasis, regulating inflammatory responses, and their diagnostic and therapeutic potential for asthma.

RESULTS

Exosomes secreted by various cell types, have emerged as crucial mediators of intercellular communication in healthy and diseased conditions. Evidence suggest that exosomes play a significant role in maintaining lung microenvironment homeostasis and contribute to asthma pathogenesis by regulating inflammatory responses. Differential exosomal content between healthy individuals and asthmatics holds promise for the development of novel asthma biomarkers. Furthermore, exosomes secreted by immune and nonimmune cells, as well as those detected in biofluids, demonstrate potential in promoting or regulating immune responses, making them attractive candidates for designing new treatment strategies for inflammatory conditions such as asthma.

CONCLUSION

Exosomes, with their ability to modulate immune responses and deliver therapeutic cargo, offer potential as targeted therapeutic tools in asthma management. Further research and clinical trials are required to fully understand the mechanisms underlying exosome-mediated effects and translate these findings into effective diagnostic and therapeutic strategies for asthma patients.

Novel insights into the roles of migrasome in cancer

Cell migration, a hallmark of cancer malignancy, plays a critical role in cancers. Improperly initiated or misdirected cell migration can lead to invasive metastatic cancer. Migrasomes are newly discovered vesicular cellular organelles produced by migrating cells and depending on cell migration. Four marker proteins [NDST1 (bifunctionalheparan sulfate N-deacetylase/N-sulfotransferase 1), EOGT (Epidermal growth factor domains pecific O-linked N-acetylglucosaminetransferase), CPQ (carboxypeptidase Q), and PIGK (phosphatidylinositol glycan anchor biosynthesis, class K)] of migrasomes were successfully identified. There are three marker proteins (NDST1, PIGK, and EOGT) of migrasome expressed in cancer. In this review, we will discuss the process of migrasome discovery, the formation of migrasome, the possible functions of migrasome, and the differences between migrasomes and exosomes, especially, the biological functions of migrasome marker proteins in cancer, and discuss some possible roles of migrasomes in cancer. We speculate that migrasomes and migracytosis can play key roles in regulating the development of cancer.

Milk-Derived Extracellular Vesicles: Biomedical Applications, Current Challenges, and Future Perspectives

Extracellular vesicles (EVs) are nano to-micrometer-sized sacs that are released by almost all animal and plant cells and act as intercellular communicators by transferring their cargos between the source and target cells. As a safe and scalable alternative to conditioned medium-derived EVs, milk-derived EVs (miEVs) have recently gained a great deal of popularity. Numerous studies have shown that miEVs have intrinsic therapeutic actions that can treat diseases and enhance human health. Additionally, they can be used as natural drug carriers and novel classes of biomarkers. However, due to the complexity of the milk, the successful translation of miEVs from benchtop to bedside still faces several unfilled gaps, especially a lack of standardized protocols for the isolation of high-purity miEVs. In this work, by comprehensively reviewing the bovine miEVs studies, we provide an overview of current knowledge and research on miEVs while highlighting their challenges and enormous promise as a novel class of theranostics. It is hoped that this study will pave the way for clinical applications of miEVs by addressing their challenges and opportunities.

Effectiveness of extracellular vesicles derived from hiPSCs in repairing hyperoxia-induced injury in a fetal murine lung explant model

BACKGROUND

Despite advances in neonatal care, the incidence of Bronchopulmonary Dysplasia (BPD) remains high among preterm infants. Human induced pluripotent stem cells (hiPSCs) have shown promise in repairing injury in animal BPD models. Evidence suggests they exert their effects via paracrine mechanisms. We aim herein to assess the effectiveness of extracellular vesicles (EVs) derived from hiPSCs and their alveolar progenies (diPSCs) in attenuating hyperoxic injury in a preterm lung explant model.

METHODS

Murine lung lobes were harvested on embryonic day 17.5 and maintained in air-liquid interface. Following exposure to 95% O2 for 24 h, media was supplemented with 5 × 106 particles/mL of EVs isolated from hiPSCs or diPSCs by size-exclusion chromatography. On day 3, explants were assessed using Hematoxylin-Eosin staining with mean linear intercept (MLI) measurements, immunohistochemistry, VEGFa and antioxidant gene expression. Statistical analysis was conducted using one-way ANOVA and Multiple Comparison Test. EV proteomic profiling was performed, and annotations focused on alveolarization and angiogenesis signaling pathways, as well as anti-inflammatory, anti-oxidant, and regenerative pathways.

RESULTS

Exposure of fetal lung explants to hyperoxia induced airspace enlargement, increased MLI, upregulation of anti-oxidants Prdx5 and Nfe2l2 with decreased VEGFa expression. Treatment with hiPSC-EVs improved parenchymal histologic changes. No overt changes in vasculature structure were observed on immunohistochemistry in our in vitro model. However, VEGFa and anti-oxidant genes were upregulated with diPSC-EVs, suggesting a pro-angiogenic and cytoprotective potential. EV proteomic analysis provided new insights in regard to potential pathways influencing lung regeneration.

CONCLUSION

This proof-of-concept in vitro study reveals a potential role for hiPSC- and diPSC-EVs in attenuating lung changes associated with prematurity and oxygen exposure. Our findings pave the way for a novel cell free approach to prevent and/or treat BPD, and ultimately reduce the global burden of the disease.

Minimal information for studies of extracellular vesicles (MISEV2023): From basic to advanced approaches

Extracellular vesicles (EVs), through their complex cargo, can reflect the state of their cell of origin and change the functions and phenotypes of other cells. These features indicate strong biomarker and therapeutic potential and have generated broad interest, as evidenced by the steady year-on-year increase in the numbers of scientific publications about EVs. Important advances have been made in EV metrology and in understanding and applying EV biology. However, hurdles remain to realising the potential of EVs in domains ranging from basic biology to clinical applications due to challenges in EV nomenclature, separation from non-vesicular extracellular particles, characterisation and functional studies. To address the challenges and opportunities in this rapidly evolving field, the International Society for Extracellular Vesicles (ISEV) updates its 'Minimal Information for Studies of Extracellular Vesicles', which was first published in 2014 and then in 2018 as MISEV2014 and MISEV2018, respectively. The goal of the current document, MISEV2023, is to provide researchers with an updated snapshot of available approaches and their advantages and limitations for production, separation and characterisation of EVs from multiple sources, including cell culture, body fluids and solid tissues. In addition to presenting the latest state of the art in basic principles of EV research, this document also covers advanced techniques and approaches that are currently expanding the boundaries of the field. MISEV2023 also includes new sections on EV release and uptake and a brief discussion of in vivo approaches to study EVs. Compiling feedback from ISEV expert task forces and more than 1000 researchers, this document conveys the current state of EV research to facilitate robust scientific discoveries and move the field forward even more rapidly.

Specific expression and blood kinetics for relaxin 2, lipocalin 2, and tissue factor pathway inhibitor 2 at the canine placenta and pregnant bloods

In general, humoral factors released from the placenta influence pregnancy progression, but the involvement of the canine placenta is often unidentified. We investigated specific genes in canine placentas and analyzed the blood dynamics of the translated proteins. Furthermore, RNAs are known to be released from placentas embedding in exosomes, a type of extracellular vesicles. Here, the presence of cell-free RNAs in pregnant serums was also confirmed. RNA specimens were purified from the normal healthy dog placentas and applied to RNA-Seq analysis. Expressions of frequent genes were confirmed by RT-PCR using placentas from other individuals and breeds. Relaxin (RLN) 2, lipocalin (LCN) 2, and tissue factor pathway inhibitor (TFPI) 2 were selected as high-expressed and placenta-specific genes. By western blot, the three factors were clearly detected in the pregnant serums. Quantitative analysis revealed that the amount of RLN2 increased significantly from non-pregnancy to day 41 of pregnancy. Regarding LCN2 and TFPI2, the protein serum levels elevated during pregnancy, but the statistical differences were not detected. Exosomes were found in all pregnant serums; however, the percentage was less than 6% in total extracellular vesicles. The cell-free RNA related to RLN2 was detected, but no elevation was confirmed during pregnancy. We found specific genes in the canine placenta and the transition of their translated protein into the blood. These factors may become useful tools for research on canine pregnancy and monitoring of reproductive management. Exosomes and cell-free RNA could not be found to be valid in canine reproduction.

Exosomes: Methods for Isolation and Characterization in Biological Samples

Exosomes are small lipid bilayer-encapsulated nanosized extracellular vesicles of endosomal origin. Exosomes are secreted by almost all cell types and are a crucial player in intercellular communication. Exosomes transmit cellular information from donor to recipient cells in the form of proteins, lipids, and nucleic acids and influence several physiological and pathological responses. Due to their capacity to carry a variety of cellular cargo, low immunogenicity and cytotoxicity, biocompatibility, and ability to cross the blood-brain barrier, these nanosized vesicles are considered excellent diagnostic tools and drug-delivery vehicles. Despite their tremendous potential, the progress in therapeutic applications of exosomes is hindered by inadequate isolation techniques, poor characterization, and scarcity of specific biomarkers. The current research in the field is focused on overcoming these limitations. In this chapter, we have reviewed conventional exosome isolation and characterization methods and recent advancements, their advantages and limitations, persistent challenges in exosome research, and future directions.

The emerging role of breast cancer derived extracellular vesicles-mediated intercellular communication in ovarian cancer progression and metastasis

Breast cancer is one of the most occurring cancer types in women worldwide and metastasizes to several organs such as bone, lungs, liver, brain, and ovaries. Extracellular vesicles (EVs) mediate intercellular signaling which has a profound effect on tumor development and metastasis. Recent developments in the field of EVs provide an opportunity to investigate the roles of EVs released from tumor cells in metastasis. In this study, we compared the effects of metastatic breast cancer-derived EVs on both nonluteinized granulosa HGrC1 and ovarian cancer OVCAR-3 cells in terms of proliferation, invasion, apoptosis, and gene expression levels. EVs were isolated from the culture medium of metastatic breast cancer cell line MDA-MB-231 by ultracentrifugation. Cell proliferation, apoptosis, cell cycle, invasion, and cellular uptake analysis were performed to clarify the roles of tumor-derived EVs in both cells. 6.85 × 108 nanoparticles of BCD-EVs were markedly increased cell proliferation as well as invasion capacity. Exposing the cells with BCD-EVs for 24 h, resulted in an accumulation of both cells in G2/M phase as determined by flow cytometry. The apoptosis assay results were consistent with cell proliferation and cell cycle results. The uptake of the BCD-EVs was efficiently internalized by both cells. In addition, marked variations in fatty acid composition between cells were observed. BCD-EVs appeared new fatty acids in HGrC1. Besides, BCD-EVs upregulated epithelial-mesenchymal transition (EMT) and proliferation-related genes. In conclusion, an environment of tumor-derived EVs changes the cellular phenotype of cancer and noncancerous cells and may lead to tumor progression and metastasis.

Filtration-based technologies for isolation, purification and analysis of extracellular vesicles

The involvement of extracellular vesicles (EVs) in cellular communication with multifactorial and multifaceted biological activity has generated significant interest, highlighting their potential diagnostic and therapeutic applications. EVs are found in nearly all biological fluids creating a broad spectrum of where potential disease markers can be found for liquid biopsy development and what subtypes can be used for treatment of diseases. Complexity of biological fluids has generated a variety of different approaches for EV isolation and identification that may in one way or another be most optimal for research studies or clinical use. Each approach has its own advantages and disadvantages, significance of which can be evaluated depending on the end goal of the study. One of the methods is based on filtration which has received attention in the past years due its versatility, low cost and other advantages. Introduction of different approaches for EV capture and analysis that are based on filtration gave rise to new subcategories of filtration techniques which are presented in this overview. Miniaturization and combination of filtration-based approaches with microfluidics is also highlighted due its future prospects in healthcare, especially point-of-need technologies.

Plant-derived nanovesicles: Further exploration of biomedical function and application potential

Extracellular vesicles (EVs) are phospholipid bilayer vesicles actively secreted by cells, that contain a variety of functional nucleic acids, proteins, and lipids, and are important mediums of intercellular communication. Based on their natural properties, EVs can not only retain the pharmacological effects of their source cells but also serve as natural delivery carriers. Among them, plant-derived nanovesicles (PNVs) are characterized as natural disease therapeutics with many advantages such as simplicity, safety, eco-friendliness, low cost, and low toxicity due to their abundant resources, large yield, and low risk of immunogenicity in vivo. This review systematically introduces the biogenesis, isolation methods, physical characterization, and components of PNVs, and describes their administration and cellular uptake as therapeutic agents. We highlight the therapeutic potential of PNVs as therapeutic agents and drug delivery carriers, including anti-inflammatory, anticancer, wound healing, regeneration, and antiaging properties as well as their potential use in the treatment of liver disease and COVID-19. Finally, the toxicity and immunogenicity, the current clinical application, and the possible challenges in the future development of PNVs were analyzed. We expect the functions of PNVs to be further explored to promote clinical translation, thereby facilitating the development of a new framework for the treatment of human diseases.

Exosomes as Novel Diagnostic Biomarkers and Therapeutic Tools in Gliomas

Exosomes constitute small extracellular vesicles that contain lipids, proteins, nucleic acids, and glycoconjugates from the secreted cells and are capable of transmitting signals between cells and coordinating cellular communication. By this means, they are ultimately involved in physiology and disease, including development, homeostasis, and immune system regulation, as well as contributing to tumor progression and neurodegenerative diseases pathology. Recent studies have shown that gliomas secrete a panel of exosomes which have been associated with cell invasion and migration, tumor immune tolerance, potential for malignant transformation, neovascularization, and resistance to treatment. Exosomes have therefore emerged as intercellular communicators, which mediate the tumor-microenvironment interactions and exosome-regulated glioma cell stemness and angiogenesis. They may induce tumor proliferation and malignancy in normal cells by carrying pro-migratory modulators from cancer cells as well as many different molecular cancer modifiers, such as oncogenic transcripts, miRNAs, mutant oncoproteins, etc., which promote the communication of cancer cells with the surrounding stromal cells and provide valuable information on the molecular profile of the existing tumor. Moreover, engineered exosomes can provide an alternative system for drug delivery and enable efficient treatment. In the present review, we discuss the latest findings regarding the role of exosomes in glioma pathogenesis, their utility in non-invasive diagnosis, and potential applications to treatment.

Adeno-Associated Virus-like Particles' Response to pH Changes as Revealed by nES-DMA

Gas-phase electrophoresis on a nano-Electrospray Gas-phase Electrophoretic Mobility Molecular Analyzer (nES GEMMA) separates single-charged, native analytes according to the surface-dry particle size. A volatile electrolyte, often ammonium acetate, is a prerequisite for electrospraying. Over the years, nES GEMMA has demonstrated its unique capability to investigate (bio-)nanoparticle containing samples in respect to composition, analyte size, size distribution, and particle numbers. Virus-like particles (VLPs), being non-infectious vectors, are often employed for gene therapy applications. Focusing on adeno-associated virus 8 (AAV8) based VLPs, we investigated the response of these bionanoparticles to pH changes via nES GEMMA as ammonium acetate is known to exhibit these changes upon electrospraying. Indeed, slight yet significant differences in VLP diameters in relation to pH changes are found between empty and DNA-cargo-filled assemblies. Additionally, filled VLPs exhibit aggregation in dependence on the applied electrolyte's pH, as corroborated by atomic force microscopy. In contrast, cryogenic transmission electron microscopy did not relate to changes in the overall particle size but in the substantial particle's shape based on cargo conditions. Overall, we conclude that for VLP characterization, the pH of the applied electrolyte solution has to be closely monitored, as variations in pH might account for drastic changes in particles and VLP behavior. Likewise, extrapolation of VLP behavior from empty to filled particles has to be carried out with caution.

Technological aspects of manufacturing and analytical control of biological nanoparticles

Extracellular vesicles (EVs) are cell-derived biological nanoparticles that gained great interest for drug delivery. EVs have numerous advantages compared to synthetic nanoparticles, such as ideal biocompatibility, safety, ability to cross biological barriers and surface modification via genetic or chemical methods. On the other hand, the translation and the study of these carriers resulted difficult, mostly because of significant issues in up-scaling, synthesis and impractical methods of quality control. However, current manufacturing advances enable EV packaging with any therapeutic cargo, including DNA, RNA (for RNA vaccines and RNA therapeutics), proteins, peptides, RNA-protein complexes (including gene-editing complexes) and small molecules drugs. To date, an array of new and upgraded technologies have been introduced, substantially improving EV production, isolation, characterization and standardization. The used-to-be "gold standards" of EV manufacturing are now outdated, and the state-of-art requires extensive revision. This review re-evaluates the pipeline for EV industrial production and provides a critical overview of the modern technologies required for their synthesis and characterization.

Hydroxychloroquine Enhances Cytotoxic Properties of Extracellular Vesicles and Extracellular Vesicle-Mimetic Nanovesicles Loaded with Chemotherapeutics

Because of their high biocompatibility, biological barrier negotiation, and functionalization properties, biological nanoparticles have been actively investigated for many medical applications. Biological nanoparticles, including natural extracellular vesicles (EVs) and synthetic extracellular vesicle-mimetic nanovesicles (EMNVs), represent novel drug delivery vehicles that can accommodate different payloads. In this study, we investigated the physical, biological, and delivery properties of EVs and EMNVs and analyzed their ability to deliver the chemotherapeutic drug doxorubicin. EMNVs and EVs exhibit similar properties, but EMNVs are more effectively internalized, while EVs show higher intracellular doxorubicin release activity. In addition, these nanotherapeutics were investigated in combination with the FDA-approved drug hydroxychloroquine (HCQ). We demonstrate that HCQ-induced lysosome destabilization and could significantly increase nanoparticle internalization, doxorubicin release, and cytotoxicity. Altogether, these data demonstrate that, from the delivery standpoint in vitro, the internalization of EMNVs and EVs and their payload release were slightly different and both nanotherapeutics had comparable cytotoxic performance. However, the synthesis of EMNVs was significantly faster and cost-effective. In addition, we highlight the benefits of combining biological nanoparticles with the lysosome-destabilizing agent HCQ that increased both the internalization and the cytotoxic properties of the particles.

Comparison of interferometric light microscopy with nanoparticle tracking analysis for the study of extracellular vesicles and bacteriophages

Research on extracellular vesicles (EVs) and bacteriophages (phages) has been steadily expanding over the past decades as many of their roles in medicine, biology, and ecosystems have been unveiled. Such interest has brought about the need for new tools to quantify and determine the sizes of these biological nanoparticles. A new device based on interferometric light microscopy (ILM), the Videodrop, was recently developed for this purpose. Here, we compared this new device to two nanoparticle tracking analysis (NTA) devices, the NanoSight and the ZetaView, for the analysis of EVs and phages. We used EVs isolated from bacteria, fecal samples, bovine milk and human cells, and phages of various sizes and shape, ranging from 30 to 120 nm of diameter. While NTA instruments correctly enumerated most phages, the Videodrop detected only the largest one, indicating a lower sensitivity threshold compared to the NTA devices. Nevertheless, the performance of the Videodrop compared favourably to that of the NTA devices for the determination of the concentration of eukaryotic EV samples. The NanoSight instrument provided the most precise size distributions but the Videodrop was by far the most time-saving device, making it worthy of consideration for studies conducted on a large number of samples composed of nanoparticles larger than 90 nm.

Electrochemical Genosensing of Overexpressed GAPDH Transcripts in Breast Cancer Exosomes

Exosomes are receiving highlighted attention as new biomarkers for the detection of cancer since they are profusely released by tumor cells in different biological fluids. In this paper, the exosomes are preconcentrated from the serum by immunomagnetic separation (IMS) based on a CD326 receptor as a specific epithelial cancer-related biomarker and detected by glyceraldehyde-3-phosphate dehydrogenase (GAPDH) transcripts. Following the lysis of the captured exosomes, the released GAPDH transcripts are amplified by reverse transcription polymerase chain reaction (RT-PCR) with a double-tagging set of primers on poly(dT)-modified-MPs to increase the sensitivity. The double-tagged amplicon is then quantified by electrochemical genosensing. The IMS/double-tagging RT-PCR/electrochemical genosensing approach is first demonstrated for the sensitive detection of exosomes derived from MCF7 breast cancer cells and compared with CTCs in terms of the analytical performance, showing an LOD of 4 × 102 exosomes μL-1. The genosensor was applied to human samples by immunocapturing the exosomes directly from serum from breast cancer patients and showed a higher electrochemical signal (3.3-fold, p < 0.05), when compared with healthy controls, suggesting an overexpression of GAPDH on serum-derived exosomes from breast cancer patients. The detection of GAPDH transcripts is performed from only 1.0 mL of human serum using specific magnetic particles, improving the analytical simplification and avoiding ultracentrifugation steps, demonstrating to be a promising strategy for minimal invasive liquid biopsy.

Exosomes and ultrasound: The future of theranostic applications

Biomaterials and pertaining formulations have been very successful in various diagnostic and therapeutic applications because of its ability to overcome pharmacological limitations. Some of them have gained significant focus in the recent decade for their theranostic properties. Exosomes can be grouped as biomaterials, since they consist of various biological micro/macromolecules and possess all the properties of a stable biomaterial with size in nano range. Significant research has gone into isolation and exploitation of exosomes as potential theranostic agent. However, the limitations in terms of yield, efficacy, and target specificity are continuously being addressed. On the other hand, several nano/microformulations are responsive to physical or chemical alterations and were successfully stimulated by tweaking the physical characteristics of the surrounding environment they are in. Some of them are termed as photodynamic, sonodynamic or thermodynamic therapeutic systems. In this regard, ultrasound and acoustic systems were extensively studied for its ability towards altering the properties of the systems to which they were applied on. In this review, we have detailed about the diagnostic and therapeutic applications of exosomes and ultrasound separately, consisting of their conventional applications, drawbacks, and developments for addressing the challenges. The information were categorized into various sections that provide complete overview of the isolation strategies and theranostic applications of exosomes in various diseases. Then the ultrasound-based disease diagnosis and therapy were elaborated, with special interest towards the use of ultrasound in enhancing the efficacy of nanomedicines and nanodrug delivery systems, Finally, we discussed about the ability of ultrasound in enhancing the diagnostic and therapeutic properties of exosomes, which could be the future of theranostics.

Mesenchymal stromal/stem cell-derived exosomes and genitourinary cancers: A mini review

Mesenchymal stromal/stem cell- (MSC-) derived exosomes are gaining popularity for their involvement in tissue repair and repressing various tumors through extensive patterns. Nevertheless, the impact of extracellular vesicles produced by stem cells on tumor formation and progression is controversial and seems to depend on several factors. The utilization of MSCs' various capabilities in urogenital neoplasms is widely regarded as a potential future therapeutic as well. These genitourinary neoplasms include prostatic neoplasms, ovarian neoplasms, cervical neoplasms, endometrial neoplasms, bladder neoplasms, and renal cell neoplasms. The present study has concentrated on the most recent information on genitourinary neoplasms employing MSCs derived exosomes' many capabilities, such as delivering effective RNAs, extensive tissue compatibility, and specificity with tumor identification without inherent limitations of cell therapy.

Concise review: Current understanding of extracellular vesicles to treat neuropathic pain

Extracellular vesicles (EVs) including exosomes are vesicular vesicles with phospholipid bilayer implicated in many cellular interactions and have the ability to transfer multiple types of cargo to cells. It has been found that EVs can package various molecules including proteins and nucleic acids (DNA, mRNA, and noncoding RNA). The discovery of EVs as carriers of proteins and various forms of RNA, such as microRNAs (miRNA) and long noncoding RNAs (lncRNA), has raised great interest in the field of drug delivery. Despite the underlying mechanisms of neuropathic pain being unclear, it has been shown that uncontrolled glial cell activation and the neuroinflammation response to noxious stimulation are important in the emergence and maintenance of neuropathic pain. Many studies have demonstrated a role for noncoding RNAs in the pathogenesis of neuropathic pain and EVs may offer possibilities as carriers of noncoding RNAs for potential in neuropathic pain treatment. In this article, the origins and clinical application of EVs and the mechanism of neuropathic pain development are briefly introduced. Furthermore, we demonstrate the therapeutic roles of EVs in neuropathic pain and that this involve vesicular regulation of glial cell activation and neuroinflammation.

Dendritic Cell Membrane-Derived Nanovesicles for Targeted T Cell Activation

T cells play an integral role in the generation of an effective immune response and are responsible for clearing foreign microbes that have bypassed innate immune system defenses and possess cognate antigens. The immune response can be directed toward a desired target through the selective priming and activation of T cells. Due to their ability to activate a T cell response, dendritic cells and endogenous vesicles from dendritic cells are being developed for cancer immunotherapy treatment. However, current platforms, such as exosomes and synthetic nanoparticles, are limited by their production methods and application constraints. Here, we engineer nanovesicles derived from dendritic cell membranes with similar properties as dendritic cell exosomes via nitrogen cavitation. These cell-derived nanovesicles are capable of activating antigen-specific T cells through direct and indirect mechanisms. Additionally, these nanovesicles can be produced in large yields, overcoming production constraints that limit clinical application of alternative immunomodulatory vesicle or nanoparticle-based methods. Thus, dendritic cell-derived nanovesicles generated by nitrogen cavitation show potential as an immunotherapy platform to stimulate and direct T cell response.

Biological Cardiac Patch Based on Extracellular Vesicles and Extracellular Matrix for Regulating Injury-Related Microenvironment and Promoting Cardiac Tissue Recovery

Cardiac patches are widely investigated to repair or regenerate diseased and aging cardiac tissues. While numerous studies looked into engineering the biochemical/biomechanical/cellular microenvironment and components in the heart tissue, the changes induced by cardiac patches and how they should be controlled to promote cardiac tissue repair/regeneration remains an important yet untapped direction, especially immunological responses. In this study, we designed and fabricated a bilaminated cardiac patch based on extracellular matrix (ECM) materials loaded with the extracellular vesicles (EVs) derived from mesenchymal stromal cells. The function of the biological material to modulate the injury-related microenvironment in a cardiac infarction model in mice was investigated. The study showed that the treatment of EV-ECM patches to the infarcted area increased the level of immunomodulatory major histocompatibility complex class II^lo macrophages in the early stage of myocardial injury to mitigate excessive inflammatory responses due to injury. The intensity of the acquired proinflammatory immune response in systemic immune organs was reduced. Further analyses indicated that the EV-ECM patches exhibited proangiogenic functions and decreased the infarct size with improved cardiac recovery in mice. The study provided insights into shaping the injury-related microenvironment through the incorporation of extracellular vesicles into cardiac patches, and the EV-ECM material is a promising design paradigm to improve the function of cardiac patches to treat myocardial injuries and diseases.

Targeting the Structural Integrity of Extracellular Vesicles via Nano Electrospray Gas-Phase Electrophoretic Mobility Molecular Analysis (nES GEMMA)

Extracellular vesicles (EVs) are in the scientific spotlight due to their potential application in the medical field, ranging from medical diagnosis to therapy. These applications rely on EV stability during isolation and purification-ideally, these steps should not impact vesicle integrity. In this context, we investigated EV stability and particle numbers via nano electrospray gas-phase electrophoretic mobility molecular analysis (nES GEMMA) and nanoparticle tracking analysis (NTA). In nES GEMMA, native, surface-dry analytes are separated in the gas-phase according to the particle size. Besides information on size and particle heterogeneity, particle number concentrations are obtained in accordance with recommendations of the European Commission for nanoparticle characterization (2011/696/EU, 18 October 2011). Likewise, and in contrast to NTA, nES GEMMA enables detection of co-purified proteins. On the other hand, NTA, yielding data on hydrodynamic size distributions, is able to relate particle concentrations, omitting electrolyte exchange (and resulting EV loss), which is prerequisite for nES GEMMA. Focusing on EVs of different origin, we compared vesicles concentrations and stability, especially after electrolyte exchange and size exclusion chromatography (SEC). Co-isolated proteins were detected in most samples, and the vesicle amount varied in dependence on the EV source. We found that depletion of co-purified proteins was achievable via SEC, but was associated with a loss of EVs and-most importantly-with decreased vesicle stability, as detected via a reduced nES GEMMA measurement repeatability. Ultimately, we propose the repeatability of nES GEMMA to yield information on EV stability, and, as a result, we propose that nES GEMMA can yield additional valuable information in EV research.

Brownian Motion Influence on AFM Exosomes' Size Measurements

Extracellular vesicles are evaluated by nanoparticle tracking analysis (NTA), providing information on their hydrodynamic diameters, and by atomic force microscopy (AFM) to calculate their geometric diameters. The aim of this study is to explore the influence of Brownian movements in a sample drop and preparation time on imaging-based measurements and to determine the relationship between the geometric and hydrodynamic sizes of the extracellular vesicles measured by the AFM and the NTA, respectively. Exosomes derived from the human prostate cancer cell line PC3 were evaluated by NTA and AFM, and those results were compared with Monte Carlo simulations. The mean size, evaluated by AFM shortly after application on the mica substrate, is less than its real value. It obtains the correct value faster for a thinner sample drop. Fitting the log-normal distribution to the geometric and hydrodynamic diameters leads to the conclusion that the latter could arise from the former by linear scaling by a factor that could be used to characterize the analyzed extracellular vesicles. The size of the vesicles attached to the mica substrate depends on time. The effect of Brownian motion and stretch of the lipid bilayer should be considered in the context of exosome AFM studies.

Exosomes in the visual system: New avenues in ocular diseases

Exosomes are a subgroup of membrane-bound extracellular vesicles secreted by all cell types and present virtually in all biological fluids. The composition of exosomes in the same cell type varies in healthy and disease conditions. Hence, exosomes research is a prime focus area for clinical research in cancer and numerous age-related metabolic syndromes. Functions of exosomes include crucial cell-to-cell communication that mediates complex cellular processes, such as antigen presentation, stem cell differentiation, and angiogenesis. However, very few studies reported the presence and role of exosomes in normal physiological and pathological conditions of specialized ocular tissues of the eye and ocular cancers. The eye being a protected sense organ with unique connectivity with the rest of the body through the blood and natural passages, we believe that the role of exosomes in ocular tissues will significantly improve our understanding of ocular diseases and their interactions with the rest of the body. We present a review that highlights the existence and function of exosomes in various ocular tissues, their role in the progression of some of the neoplastic and non-neoplastic conditions of the eyes.

Asymmetric depth-filtration: A versatile and scalable method for high-yield isolation of extracellular vesicles with low contamination

We developed a novel asymmetric depth filtration (DF) approach to isolate extracellular vesicles (EVs) from biological fluids that outperforms ultracentrifugation and size-exclusion chromatography in purity and yield of isolated EVs. By these metrics, a single-step DF matches or exceeds the performance of multistep protocols with dedicated purification procedures in the isolation of plasma EVs. We demonstrate the selective transit and capture of biological nanoparticles in asymmetric pores by size and elasticity, low surface binding to the filtration medium, and the ability to cleanse EVs held by the filter before their recovery with the reversed flow all contribute to the achieved purity and yield of preparations. We further demonstrate the method's versatility by applying it to isolate EVs from different biofluids (plasma, urine, and cell culture growth medium). The DF workflow is simple, fast, and inexpensive. Only standard laboratory equipment is required for its implementation, making DF suitable for low-resource and point-of-use locations. The method may be used for EV isolation from small biological samples in diagnostic and treatment guidance applications. It can also be scaled up to harvest therapeutic EVs from large volumes of cell culture medium.

Dynamic surface tension probe for measuring the concentration of extracellular vesicles

The concentration of extracellular vesicles (EVs) is an essential attribute of biofluids and EV preparations. EV concentration in body fluids was correlated with health status. The abundance of EV secreted by cultured cells into growth medium is vital in signaling studies, tissue and disease models, and biomanufacturing of acellular therapeutic secretome. A limited number of physical principles sensitive to EV concertation have been discovered so far. Particle-by-particle counting methods enumerate individual particles scattering light, modulating the Coulter current, or appearing in EM images. The available ensemble techniques in current use rely on the concentration-dependent signal intensity, as in the case of ELISA. In this study, we propose for the first-time the ensemble-based characterization of EV concentration by dynamic surface tension (DST) probe and demonstrate its implementation. We show that DST measurements agree with the widely used NTA measurements of EV concertation. The proposed method is low-cost and requires only basic laboratory equipment for implementation.

Quantification of Desiccated Extracellular Vesicles by Quartz Crystal Microbalance

Extracellular vesicle (EV) quantification is a procedure through which the biomedical potential of EVs can be used and their biological function can be understood. The number of EVs isolated from cell culture media depends on the cell status and is especially important in studies on cell-to-cell signaling, disease modeling, drug development, etc. Currently, the methods that can be used to quantify isolated EVs are sparse, and each have limitations. In this report, we introduce the application of a quartz crystal microbalance (QCM) as a biosensor for quantifying EVs in a small drop of volatile solvent after it evaporates and leaves desiccated EVs on the surface of the quartz crystal. The shifts in the crystal’s resonant frequency were found to obey Sauerbrey’s relation for EV quantities up to 6 × 10⁷, and it was determined that the biosensors could resolve samples that differ by at least 2.7 × 10⁵ EVs. A ring-shaped pattern enriched in EVs after the samples had dried on the quartz crystal is also reported and discussed. QCM technology is highly sensitive and only requires small sample volumes and is significantly less costly compared with the approaches that are currently used for EV quantification.

Advances in exosome biomarkers for cervical cancer

Cervical cancer (CC) ranks as the fourth most frequently diagnosed malignancy in females worldwide. Exosomes are a subclass of extracellular vesicles released by nearly all types of cells that act as cargo transport vehicles, carrying proteins, and genetic material (such as miRNAs, long noncoding RNAs, and mRNAs) derived from their parent cells may affect receiving cells and thus have emerged as key players in several biological processes, including inflammatory pathways. In this review, we concentrated on the findings of exosome investigations in CC, particularly their components. They direct the actions of CC cells by inducing surface molecules associated with various biological pathways. We summarized the current knowledge of exosomal RNAs and proteins from CC cells and discussed the feasibility of exosomes as potential biomarkers for CC. We suggest that cancer-derived exosomes promote metastasis in CC by supporting EMT, controlling the proliferation, invasion, or migration of cancer cells, as well as influencing immune escape and aiding angiogenesis. Overall, cancer-derived exosomes are critical in the progression of CC, and further studies are necessary to advance our understanding of the clinical value of exosomes in CC.

Extracellular vesicles as natural therapeutic agents and innate drug delivery systems for cancer treatment: Recent advances, current obstacles, and challenges for clinical translation

As cancer poses a significant threat to the well-being of humans on a global scale, many researchers have embarked on the search for effective anticancer therapeutic agents. In recent years, many drugs have been shown to have extraordinary anticancer effects. However, in a lot of cases the treatment is accompanied by undesirable side effects due to some intrinsic properties linked to the therapeutic agents, such as poor targeting selectivity and short half-life in the circulation. In this regard, extracellular vesicles (EVs), a diverse family of natural cell-derived vesicles, steal the show as potential anticancer immunotherapy or delivery vectors of anticancer agents since they are an innate mechanism of intercellular communication. Here, we describe some of the most hotly-debated issues regarding the use of EVs as anticancer therapeutics. First, we review the biology of EVs providing the most up-to-date definition of EVs as well as highlighting their circulation kinetics and homing properties. Next, we share our views on popular methods reported for EV isolation, characterization, and functional analysis. Pioneering and innovative reports along with emerging challenges in the field of EV imaging and EV drug loading strategies are then discussed. Finally, we examine in detail the therapeutic application of EVs in cancer treatment, including their role in cancer immunotherapy and as natural delivery systems for anticancer agents including natural compounds such as paclitaxel and doxorubicin. We consider standardised protocols and proper analytical approaches to be crucial in improving the reproducibility and rigor in EV research and ensuring the successful translation of EVs as anticancer therapeutics.

Circadian regulation of protein cargo in extracellular vesicles

The circadian clock controls many aspects of physiology, but it remains undescribed whether extracellular vesicles (EVs), including exosomes, involved in cell-cell communications between tissues are regulated in a circadian pattern. We demonstrate a 24-hour rhythmic abundance of individual proteins in small EVs using liquid chromatography-mass spectrometry in circadian-synchronized tendon fibroblasts. Furthermore, the release of small EVs enriched in RNA binding proteins was temporally separated from those enriched in cytoskeletal and matrix proteins, which peaked during the end of the light phase. Last, we targeted the protein sorting mechanism in the exosome biogenesis pathway and established (by knockdown of circadian-regulated flotillin-1) that matrix metalloproteinase 14 abundance in tendon fibroblast small EVs is under flotillin-1 regulation. In conclusion, we have identified proteomic time signatures for small EVs released by tendon fibroblasts, which supports the view that the circadian clock regulates protein cargo in EVs involved in cell-cell cross-talk.

Research progress on the role and mechanism of action of exosomes in autoimmune thyroid disease

Exosomes are widely distributed extracellular vesicles (EVs), which are currently a major research hotspot for researchers based on their wide range of sources, stable membrane structure, low immunogenicity, and containing a variety of biomolecules. A large number of literatures have shown that exosomes and exosome cargoes (especially microRNAs) play an important role in the activation of inflammation, development of tumor, differentiation of cells, regulation of immunity and so on. Studies have found that exosomes can stimulate the immune response of the body and participate in the occurrence and development of various diseases, including autoimmune diseases. Furthermore, the potential of exosomes as therapeutic tools in various diseases has also attracted much attention. Autoimmune thyroid disease (AITD) is one of the most common autoimmune diseases, mainly composed of Graves' disease (GD) and Hashimoto's thyroiditis (HT), which affects the health of many people and has a genetic predisposition, but its pathogenesis is still being explored. Starting from the relevant biological characteristics of exosomes, this review summarizes the current research status of exosomes and the association between exosomes and some diseases, with a focus on the situation of AITD and the potential role of exosomes (including substances in their vesicles) in AITD in combination with the current published literature, aiming to provide new directions for the pathogenesis, diagnosis or therapy of AITD.Supplemental data for this article is available online at.

Extracellular Vesicles as an Emerging Treatment Option for Intervertebral Disc Degeneration: Therapeutic Potential, Translational Pathways, and Regulatory Considerations

Emergent approaches in regenerative medicine look toward the use of extracellular vesicles (EVs) as a next-generation treatment strategy for intervertebral disc (IVD) degeneration (IVDD) because of their ability to attenuate chronic inflammation, reduce apoptosis, and stimulate proliferation in a number of tissue systems. Yet, there are no Food and Drug Administration (FDA)-approved EV therapeutics in the market with an indication for IVDD, which motivates this article to review the current state of the field and provide an IVD-specific framework to assess its efficacy. In this systematic review, 29 preclinical studies that investigate EVs in relation to the IVD are identified, and additionally, the regulatory approval process is reviewed in an effort to accelerate emerging EV-based therapeutics toward FDA submission and timeline-to-market. The majority of studies focus on nucleus pulposus responses to EV treatment, where the main findings show that stem cell-derived EVs can decelerate the progression of IVDD on the molecular, cellular, and organ level. The findings also highlight the importance of the EV parent cell's pathophysiological and differentiation state, which affects downstream treatment responses and therapeutic outcomes. This systematic review substantiates the use of EVs as a promising cell-free strategy to treat IVDD and enhance endogenous repair.

Lung cell membrane-coated nanoparticles capable of enhanced internalization and translocation in pulmonary epithelial cells

Cell membrane-coated nanoparticles (CMCNP), which involve coating a core nanoparticle (NP) with cell membranes, have been gaining attention due to their ability to mimic the properties of the cells, allowing for enhanced delivery and efficacy of therapeutics. Two CMCNP systems comprised of an acetalated dextran-based NP core loaded with curcumin (CUR) coated with cell membranes derived from pulmonary epithelial cells were developed. The NP were approximately 200 nm and their surface charges varied based on their coating, where CMCNP systems exhibited negative surface charge like natural cell membranes. The NP were smooth, spherical, and homogeneous with distinct coatings on their cores. Minimal in vitro toxicity was observed for the NP and controlled release of CUR was observed. The CMCNP internalized into and translocated across an in vitro pulmonary epithelial monolayer significantly more than the control NP. Blocking endocytosis pathways reduced the transcytosis of NP, indicating a relationship between endocytosis and transcytosis. These newly developed CMCNP have the potential to be used in pulmonary drug delivery applications to potentially enhance NP internalization and transport into and across the pulmonary epithelium.

Calcium ion effect on phospholipid bilayers as cell membrane analogues

Ion attachment can modify stability and structure of phospholipid bilayers. Of particular importance is the interaction of phospholipids with divalent cations, such as calcium ions playing an important role in numerous cellular processes. The aim of our study was to determine effects of calcium ions on phospholipid membranes employing two cell membrane analogues, liposomes and planar lipid bilayers, and for the first time the combination of two instrumental setups: gas-phase electrophoresis (nES GEMMA instrumentation) and electrical (capacitance and resistance) measurements. Liposomes and planar lipid bilayers consisted of phosphatidylcholine, cholesterol and phosphatidylethanolamine. Liposomes were prepared from dried lipid films via hydration while planar lipid bilayers were formed using a Mueller-Rudin method. Calcium ions were added to membranes from higher concentrated stock solutions. Changes in phospholipid bilayer properties due to calcium presence were observed for both studied cell membrane analogues. Changes in liposome size were observed, which might either be related to tighter packing of phospholipids in the bilayer or local distortions of the membrane. Likewise, a measurable change in planar lipid bilayer resistance and capacitance was observed in the presence of calcium ions, which can be due to an increased rigidity and tighter packing of the lipid molecules in the bilayer.

Magnetic particle based liquid biopsy chip for isolation of extracellular vesicles and characterization by gene amplification

Extracellular vesicles (EVs) are the cell-derived vesicles which play a critical role in cell-to-cell communication, and disease progression. These vesicles contain a myriad of substances like RNA, DNA, proteins, and lipids from their origin cells, offering a good source of biomarkers. The existing methods for the isolation of EVs are time-consuming, lack yield and purity, and expensive. In this work, we present a magnetic particle based liquid biopsy chip for the isolation of EVs by using a synthetic peptide, Vn96. To ensure capture efficiency, a 3D mixer is integrated in the chip, along with a sedimentation unit, which allows EV-captured magnetic particles to settle in it based on gravity assisted sedimentation. The captured EVs are then isolated for their elution and validation. The EVs are characterized by the scanning electron microscopy (SEM) measurements and the ability of capture and isolation of EVs is validated by the nanoparticle tracking analysis (NTA) and atomic force microscopy (AFM). The DNA content of the EVs is further characterized by the absolute quantification of a housekeeping gene (RNase P) copies using droplet digital PCR (ddPCR). The results show that the chip can capture and isolate the EVs, without affecting their morphology. Thus, the liquid biopsy chip can be considered as a potential point of care device for diagnostics in a clinical setting.

Blood Nanoparticles - Influence on Extracellular Vesicle Isolation and Characterization

Blood is a rich source of disease biomarkers, which include extracellular vesicles (EVs). EVs are nanometer-to micrometer-sized spherical particles that are enclosed by a phospholipid bilayer and are secreted by most cell types. EVs reflect the physiological cell of origin in terms of their molecular composition and biophysical characteristics, and they accumulate in blood even when released from remote organs or tissues, while protecting their cargo from degradation. The molecular components (e.g., proteins, miRNAs) and biophysical characteristics (e.g., size, concentration) of blood EVs have been studied as biomarkers of cancers and neurodegenerative, autoimmune, and cardiovascular diseases. However, most biomarker studies do not address the problem of contaminants in EV isolates from blood plasma, and how these might affect downstream EV analysis. Indeed, nonphysiological EVs, protein aggregates, lipoproteins and viruses share many molecular and/or biophysical characteristics with EVs, and can therefore co-isolate with EVs from blood plasma. Consequently, isolation and downstream analysis of EVs from blood plasma remain a unique challenge, with important impacts on the outcomes of biomarker studies. To help improve rigor, reproducibility, and reliability of EV biomarker studies, we describe here the major contaminants of EV isolates from blood plasma, and we report on how different EV isolation methods affect their levels, and how contaminants that remain can affect the interpretation of downstream EV analysis.

A possible role of gas-phase electrophoretic mobility molecular analysis (nES GEMMA) in extracellular vesicle research

The emerging role of extracellular vesicles (EVs) as biomarkers and their envisioned therapeutic use require advanced techniques for their detailed characterization. In this context, we investigated gas-phase electrophoresis on a nano electrospray gas-phase electrophoretic mobility molecular analyzer (nES GEMMA, aka nES differential mobility analyzer, nES DMA) as an alternative to standard analytical techniques. In gas-phase electrophoresis, single-charged, surface-dry, native, polydisperse, and aerosolized analytes, e.g., proteins or bio-nanoparticles, are separated according to their electrophoretic mobility diameter, i.e., globular size. Subsequently, monodisperse particles are counted after a nucleation step in a supersaturated atmosphere as they pass a focused laser beam. Hence, particle number concentrations are obtained in accordance with recommendations of the European Commission for nanoparticle characterization (2011/696/EU from October 18th, 2011). Smaller sample constituents (e.g., co-purified proteins) can be detected next to larger ones (e.g., vesicles). Focusing on platelet-derived EVs, we compared different vesicle isolation techniques. In all cases, nanoparticle tracking analysis (NTA) confirmed the presence of vesicles. However, nES GEMMA often revealed a significant co-purification of proteins from the sample matrix, precluding gas-phase electrophoresis of less-diluted samples containing higher vesicle concentrations. Therefore, mainly peaks in the protein size range were detected. Mass spectrometry revealed that these main contaminants belonged to the group of globulins and coagulation-related components. An additional size exclusion chromatography (SEC) step enabled the depletion of co-purified, proteinaceous matrix components, while a label-free quantitative proteomics approach revealed no significant differences in the detected EV core proteome. Hence, the future in-depth analysis of EVs via gas-phase electrophoresis appears feasible.

Immunomodulatory effects exerted by extracellular vesicles from Staphylococcus epidermidis and Staphylococcus aureus isolated from bone-anchored prostheses

Staphylococcus aureus and Staphylococcus epidermidis are the bacteria that most frequently cause osteomyelitis. This study aimed to determine whether staphylococci isolated from osteomyelitis associated with septic loosening of orthopedic prostheses release extracellular vesicles (EVs) and, if so, to determine tentative immunomodulatory effects on the human monocytic cell line THP-1. EVs were isolated from bacterial cultures using filtration and ultracentrifugation and characterized by scanning electron microscopy, nanoparticle tracking analysis and Western Blot. The cytotoxic effect of EVs was analyzed by NucleoCounter and lactate dehydrogenase (LDH) analyses. Confocal laser scanning microscopy was employed to visualize the uptake of EVs by THP-1 cells. Activation of the transcription factor nuclear factor-κB (NF-κB) was determined in THP1-Blue™ NF-κB cells, and the gene expression and secretion of cytokines were determined by quantitative polymerase chain reaction and enzyme-linked immunosorbent assay, respectively. All investigated strains, irrespective of their biofilm formation ability, were able to secrete EVs in vitro. The S. aureus strains produced significantly more EVs than the S. epidermidis strains. Both S. aureus-derived EVs and S. epidermidis-derived EVs were internalized by THP-1 cells, upregulated Toll-like receptor 3 (TLR3) gene expression, activated NF-κB, and promoted the gene expression and secretion of interleukin (IL)-8, monocyte chemoattractant protein (MCP)-1, matrix metallopeptidase (MMP)-9 and IL-10. Whereas EVs from both staphylococcal species upregulated the proapoptotic DNA damage-inducible transcript 4 (DDIT4) gene and downregulated the antiapoptotic B-cell lymphoma 2 (Bcl-2) gene, cytolysis was preferentially induced in S. aureus EV-stimulated cells, possibly related to the expression of cytolytic proteins predominantly in S. aureus EVs. In conclusion, staphylococcal EVs possess potent cytolytic and immunomodulatory properties.

Decoration of Squalenoyl-Gemcitabine Nanoparticles with Squalenyl-Hydroxybisphosphonate for the Treatment of Bone Tumors

Therapeutic perspectives of bone tumors such as osteosarcoma remain restricted due to the inefficacy of current treatments. We propose here the construction of a novel anticancer squalene‐based nanomedicine with bone affinity and retention capacity. A squalenyl‐hydroxybisphosphonate molecule was synthetized by chemical conjugation of a 1‐hydroxyl‐1,1‐bisphosphonate moiety to the squalene chain. This amphiphilic compound was inserted onto squalenoyl‐gemcitabine nanoparticles using the nanoprecipitation method. The co‐assembly led to nanoconstructs of 75 nm, with different morphology and colloidal properties. The presence of squalenyl‐hydroxybisphosphonate enhanced the nanoparticles binding affinity for hydroxyapatite, a mineral present in the bone. Moreover, the in vitro anticancer activity was preserved when tested in commercial and patient‐treated derived pediatric osteosarcoma cells. Further in vivo studies will shed light on the potential of these nanomedicines for the treatment of bone sarcomas.