Exosome Isolation Research Articles

Diagnosis and Biomarker Screening of Endometrial Cancer Enabled by a Versatile Exosome Metabolic Fingerprint Platform.

Exosomes have emerged as a revolutionary tool for liquid biopsy (LB), as they carry specific cargo from cells. Profiling the metabolites of exosomes is crucial for cancer diagnosis and biomarker discovery. Herein, we propose a versatile platform for exosomal metabolite assay of endometrial cancer (EC). The platform is based on a nanostructured composite material comprising gold nanoparticle-coated magnetic COF with aptamer modification (Fe3O4@COF@Au-Apt). The unique design and novel synthesis strategy of Fe3O4@COF@Au-Apt provide the material with a large specific surface area, enabling the efficient and specific isolation of exosomes. The exosomes captured Fe3O4@COF@Au-Apt can be directly used as the laser desorption/ionization mass spectrometry (LDI-MS) matrix for rapid exosomal metabolic patterns. By integrating these functionalities into a single platform, the analytical process is simplified, eliminating the need for additional elution steps and minimizing potential sample loss, resulting in large-scale exosomal metabolic fingerprints. Combining with machine learning algorithms on the metabolic patterns, accurate discrimination between endometrial patients (EGs) and benign controls (CGs) was achieved, and the area under the receiver operating characteristic curve of the blind test cohort was 0.924. Confusion matrix analysis of important metabolic fingerprint features further demonstrates the high accuracy of the proposed approach toward EC diagnosis, with an overall accuracy of 94.1%. Moreover, four metabolites, namely, hydroxychalcone, l-acetylcarnitine, elaidic acid, and glutathione, have been identified as potential biomarkers of EC. These results highlight the great value of the integrated exosome metabolic fingerprint platform in facilitating low-cost and high-throughput characterization of exosomal metabolites for cancer diagnosis and biomarker discovery.

Isolation and Characterization of Exosomes from Ocular Samples.

Exosomes are microsize vesicles secreted by nearly all cells to the extracellular space. The vesicles transport cell signaling and communicate with other cells. Ultracentrifugation is the standard method to isolate exosomes from culture media or body fluid. Without ultracentrifuge, exosomes can be precipitated by polyethylene glycol or separated by size exclusion chromatography. After isolation, nanoparticle tracking analysis can help to estimate the size and concentration of exosome samples. Transmission electron microscopy can directly show the size and morphology of exosomes. Moreover, the sample should be characterized by the expression of several exosome biomarker proteins. Exosomal contents such as proteins and miRNAs could be profiled using appropriate technologies.

Insights on the Characteristics and Therapeutic Potential of Mesenchymal Stem Cell-derived Exosomes for Mitigation of Alzheimer's Disease's Pathogenicity: A Systematic Review.

Alzheimer's disease (AD) remains a progressive neurodegenerative disease with no cure. Treatment of AD relies on administering drugs that only subside the symptoms. In recent studies, mesenchymal stem cell (MSC)-exosomes have been marked to possess therapeutic potential for treating AD. This study aims to systematically review and analyse findings that focus on the isolation, characterisation, and sources of MSC-derived exosomes used to unravel the therapeutic potential of these exosomes targeting AD using in vitro and in vivo models. It is hypothesised that MSC-exosomes exhibit high therapeutic potential for AD treatment by exerting various modes of action. PubMed, Scopus, and Medline were used to find relevant published works from January 2016 until December 2020, using assigned keywords including "Alzheimer's disease", "secretome", and "exosomes". Only research articles meeting the predefined inclusion/exclusion criteria were selected and analysed. The risk of bias was assessed using the Office of Health Assessment and Translation tool (OHAT). A total of 17 eligible in vivo and in vitro studies were included in this review. Bone marrow-derived stem cells (BMSCs) were the most used source for exosome isolation, even though studies on exosomes from adipose-derived stem cells (ADSCs) and human umbilical cord stem cells (HUCSCs) provide more information on the characteristics. When the risk of bias was assessed, the studies presented various levels of biases. Notably, the in vitro and in vivo studies revealed neuroprotective properties of MSC-exosomes through different modes of action to alleviate AD pathology. Our review discovered that most MSC exosomes could degrade Aβ plaques, enhance neurogenesis, extenuate neuroinflammatory response through microglial activation, regulate apoptosis and reduce oxidative stress. Delivery of exosomal micro-RNAs was also found to reduce neuroinflammation. Findings from this review provided convincing systematic evidence highlighting the therapeutic properties of MSC-derived exosomes as a prospective source for cell-free (acellular) therapy in treating AD.

‘Selected’ Exosomes from Sera of Elderly Severe Obstructive Sleep Apnea Patients and Their Impact on Blood–Brain Barrier Function: A Preliminary Report

Obstructive sleep apnea syndrome (OSAS) affects a large part of the aging population. It is characterized by chronic intermittent hypoxia and associated with neurocognitive dysfunction. One hypothesis is that the blood–brain barrier (BBB) functions could be altered by exosomes. Exosomes are nanovesicles found in biological fluids. Through the study of exosomes and their content in tau and amyloid beta (Aβ), the aim of this study was to show how exosomes could be used as biomarkers of OSAS and of their cognitive disorders. Two groups of 15 volunteers from the PROOF cohort were selected: severe apnea (AHI > 30) and control (AHI < 5). After exosome isolation from blood serum, we characterized and quantified them (CD81, CD9, CD63) by western blot and ELISAs and put them 5 h in contact with an in vitro BBB model. The apparent permeability of the BBB was measured using sodium-fluorescein and TEER. Cell ELISAs were performed on tight junctions (ZO-1, claudin-5, occludin). The amount of tau and Aβ proteins found in the exosomes was quantified using ELISAs. Compared to controls, OSAS patients had a greater quantity of exosomes, tau, and Aβ proteins in their blood sera, which induced an increase in BBB permeability in the model and was reflected by a loss of tight junction’ expression. Elderly patients suffering severe OSAS released more exosomes in serum from the brain compartment than controls. Such exosomes increased BBB permeability. The impact of such alterations on the risk of developing cognitive dysfunction and/or neurodegenerative diseases is questioned.

Exosomal miR-494 Regulates the Biological Behavior of Trophoblasts by Targeting mTOR in Unexplained Recurrent Spontaneous Abortion.

Recurrent spontaneous abortion (RSA) is a pregnancy disorder, and trophoblasts are involved in its complex pathogenesis. This study aimed to identify the functional role of exosomal miR-494 in promoting the development of unexplained RSA (uRSA). 15 uRSA tissues and 15 healthy controls were collected to compare the exosomal miR-494 expression. The ultracentrifugation method was used for serum exosome isolation, and exosome characteristics were examined using transmission electron microscopy (TEM). The affection of exosomal miR-494 on HTR-8/SVneo cells were determined by CCK-8, EdU, Wound healing, and Transwell assays. Our findings demonstrated that miR-494 levels were markedly lower in placental tissue and plasma exosomes from patients with uRSA than in normal pregnant women. Furthermore, treatment with miR-494-overexpressing exosomes reduced the viability, invasion, and migration of HTR-8/SVneo cells. In terms of regulation, exosomal miR-494 downregulated mTOR levels in HTR-8/SVneo cells. Mechanism research suggested that exosomal miR-494 reduces the viability, invasion, and migration of trophoblasts by targeting mTOR. Exosomal miR-494 and mTOR are potential predicative biomarkers and therapeutic targets for uRSA patients.

Preparation of Dysprosium(III)-Metal Organic Framework Nanofiber for Exosome Capture and Biomarker Discovery toward Liver Disease.

As an emerging source for liquid biopsy, exosomes hold significant promise for clinical diagnosis. However, commonly used exosome isolation methods (e.g., ultracentrifugation) suffer from low throughput for a large number of clinical samples. Herein, a dysprosium-metal organic framework was synthesized and doped with nanofibers by electrospinning for efficient capture of exosomes from body fluid. With the integration of multichannel of pipet or robot automatic workstation, high throughput exosome isolation can be achieved with clinical samples with high reproducibility. To evaluate the clinical value of the developed method, urinary exosomes were enriched from 34 liver disease samples of different stages for the profiling of metabolites by mass spectrometry. The results showed that HCC, cirrhosis, and healthy controls can be significantly differentiated by the Random Forest classification model. The dysprosium-metal organic framework has promising applications in exosome-based liquid biopsy for large-scale clinical disease diagnosis.

Co-delivery of temozolomide and quercetin with folic acid-conjugated exosomes in glioblastoma treatment.

Aim: The study aims to improve glioblastoma multiforme (GBM) treatment by combining temozolomide (TMZ) and quercetin (Qct), using folic acid (FA)-conjugated exosomes to overcome TMZ resistance and enhance blood-brain barrier (BBB) penetration.Methods: Exosomes were isolated and after characterizing and modifying their surfaces with FA, drug loading of TMZ and Qct into exosomes was done. In vitro assays, including cell viability tests, RT-PCR, Western-blotting and flow-cytometry, were performed using U87MG and U251MG GBM cell lines. In vivo analysis included administering exosome-drug formulations to glioblastoma-bearing Wistar rats, monitored through optical imaging and PET scans, followed by post-mortem immunohistochemistry and histological examination.Results: The results showed successful exosome isolation and FA conjugation, with drug release studies indicating accelerated release of TMZ and Qct in acidic conditions, enhancing cytotoxicity. Immunofluorescence indicated greater exosome uptake in GBM cells due to FA conjugation. Cell viability assays demonstrated increased toxicity of the combination therapy, correlating with elevated apoptosis. In vivo studies revealed significant tumor size reduction, alongside increased apoptosis and reduced angiogenesis, particularly in the TMZ-Qct-Exo-FA group.Conclusion: FA-conjugated exosomes loaded with TMZ and Qct represent a promising strategy to enhance GBM treatment efficacy by improving drug delivery, apoptosis induction and inhibiting the PI3K/Akt/mTOR pathway.

Investigating the Suitability of Mare's Milk-Derived Exosomes as Potential Drug Carriers.

Exosomes are cell-derived, membrane-surrounded particles that deliver bioactive molecules to various cells. Due to their small size, low immunogenicity, extended blood circulation, and involvement in cellular communication, they hold potential as effective drug carriers. Exosomes are present in various biological fluids, including mare's milk, a traditional drink in Central Asia. This study aims to compare exosome isolation methodologies and determine the stability of mare's milk-derived exosomes as potential therapeutic carriers. Three extraction methods-immunoprecipitation, size exclusion chromatography, and total exosome isolation-were compared in terms of exosome characteristics, purity, and content. The isolated exosomes were then loaded with quercetin, and their ability to increase its bioavailability was tested in vitro and in vivo. Total exosome isolation was identified as the most efficient method for producing high-quality exosomes. These exosomes were loaded with quercetin and compared to free quercetin and exosomes alone. Exosomes loaded with 80 µM quercetin significantly restored β-galactosidase activity and cellular viability in doxorubicin-treated cells, exhibiting similar potency to 160 µM free quercetin. In aged model animals, treatment with quercetin-loaded exosomes resulted in significantly less acute and subacute damage to the myocardium, kidneys, and liver compared to untreated control animals. This study provides a proof-of-concept that mare's milk-derived exosomes can be effectively absorbed by cells and animal tissues, supporting their potential use as drug carriers.

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

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

Association of Elevated Exosomal miR-21 Levels with Nonunion in Clavicular Fractures Post-ORIF: A Prospective Analysis

BackgroundThis study investigates the relationship between plasma exosomal miRNAs and nonunion risk following open reduction and internal fixation (ORIF) of clavicle fractures, aiming to identify predictive molecule to enhance patient management and personalized orthopedic care. MethodsConducted as a prospective cohort study at Taian City Central Hospital, participants included individuals with unilateral, closed clavicle fractures who underwent ORIF (n = 763, 546 males and 217 females). Plasma samples were collected preoperatively for exosome isolation and miRNA extraction, specifically analyzing miR-100, miR-124, miR-125b, and miR-21 using quantitative polymerase chain reaction (qPCR). Patients were classified into union and nonunion groups based on follow-up outcomes at a minimum of three months post-surgery. ResultsOut of 763 patients, 720 achieved union while 43 developed nonunion. Notably, the nonunion group exhibited significantly elevated exosomal miR-21 expression levels. Univariate analysis demonstrated a significant association between high miR-21 expression and nonunion occurrence (Relative Risk [RR] = 1.82, P = 0.0004). Multivariate logistic regression analysis corroborated this association (RR > 1.8, P < 0.05), adjusting for covariates. High miR-21 levels (3.12 to 7.89) were robustly associated with nonunion outcomes (RR > 4), independent of other factors. Receiver operating characteristic (ROC) curve analysis indicated certain clinical diagnostic value of miR-21 for predicting nonunion (Area Under the Curve [AUC] = 0.7885). ConclusionsThe elevated preoperative levels of exosomal miR-21 were significantly associated with an increased risk of bone nonunion at three months ORIF in patients with clavicle fractures, indicating that miR-21 holds potential as a non-specific predictive molecule.

Extract from Falcaria vulgaris loaded with exosomes for the treatment of hypertension in pregnant mice: In vitro and In vivo investigations.

Hypertensive disorders during pregnancy pose significant risks to both maternal and fetal health, necessitating safe and effective therapeutic interventions. This study aimed to investigate the potential of an extract derived from Falcaria vulgaris (FV), loaded with exosomes to form the Exo/FV complex, as a novel therapeutic agent for the management of hypertension in pregnant mice: antioxidants, antimicrobials, and phenolic compounds present in FV lower blood pressure. The isolation of exosomes was done by ultracentrifugation methods and the FV was loaded into the exosomes by electroporation method. The Exo/FV was found to be spherical with diameter ranges from 20 to 30nm and they were tested for biocompatibility in NHI 3T3 cell lines and found to be effective. This research investigated invivo hypertension in mice induced by L-NAME and treated with FV and Exo/FV and found that AChE and MAO determine mice's redox state tends to reduce blood pressure. Increased non-protein thiol (NP-SH) and decreased lipid peroxidation were also found, and PDE-5, ACE, Arginase, and MDA activity has also been tested. This analysis showed that Exo/FV effectively treated hypertension during pregnancy.

Specific isolation and quantification of PD-L1 positive tumor derived exosomes for accurate breast cancer discrimination via aptamer-functionalized magnetic composites and SERS immunoassay

PD-L1 positive tumor derived exosomes (TEXsPD−L1) play a significant role in disease progression, tumor metastasis and cancer immunotherapy. However, the overlap of PD-L1 between TEXs and non-tumor derived exosomes (non-TEXs) restricts the specific isolation and quantification of TEXPD−L1 from clinical samples. Herein, a new aptamer-functionalized and hydrophilic immunomagnetic substrate was designed by decorating generation 5 polyamidoamine dendrimers (G5 PAMAM), zwitterionic trimethylamine N-oxide (TMAO) and EpCAM (Epithelial cell adhesion molecule) aptamers on magnetic cores sequentially (Fe3O4@PAMAM@TMAO@Aptamer, named as FPTA) for rapid target and efficient capture of TEXs. The FPTA substrate gathered excellent characters of strong magnetic responsiveness of Fe3O4, abundant affinity sites of PAMAM, strong hydrophilicity of TMAO and enhanced affinity properties of EpCAM aptamers. Because of these advantages, FPTA can isolate TEXs quickly within 30min with high capture efficiency of 90.5 % ± 3.0 % and low nonspecific absorption of 8.2 % ± 2.0 % for non-TEXs. Furthermore, PD-L1 (Programmed cell death-ligand 1) positive TEXs (TEXsPD−L1) from the captured TEXs were recognized and quantitatively analyzed by utilizing SERS (surface-enhanced Raman spectroscopy) reporter molecules 4-NTP (4-Nitrothiophenol) on PD-L1 aptamers-functionalized gold immunoaffinity probe. The signal of TEXsPD−L1 was converted to SERS signal of 4-NTP at 1344 cm−1 which exhibited a linear correlation to concentration of TEXsPD−L1(R2 = 0.9905). With these merits, this strategy was further applied to clinical plasma samples from breast cancer (BC) patients and healthy controls (HC), exhibited an excellent diagnosis accuracy with area under curve (AUC) of receiver operating characteristic (ROC) curve reaching 0.988. All these results demonstrate that the FPTA immunomagnetic substrate combined with SERS immunoaffinity probe may become a generic tool for specific isolation and quantitative analysis of PD-L1 positive tumor-derived exosomes in clinics.

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.

Recent advances on strategies and technologies for isolation of bovine milk-derived exosomes: An overview

Exosomes are small extracellular vesicles that play an important role in intercellular communication by facilitating the transfer of cell-specific constituents of the source cell to the recipient cell. They are secreted by various cell types and are available in all body fluids. Milk has been a part of the human diet since ages and is known to contain diverse bioactive components, including exosomes. Milk-derived exosomes (MDE) contain specific cargo with proteins, lipids, nucleic acids and other bioactive molecules that help in cell-to-cell communication and can alter the biological and physical processes of the recipient cells. These MDE can act as excellent nanocarriers for the delivery of drugs due to their stability and low immunogenicity. In this comprehensive review, the conventional isolation strategies based on ultracentrifugation, immunocapture, polymer-based precipitation, and chromatography and also the emerging technologies like microfluidic chips are discussed in detail. These provide functionally intact exosomes with high recovery rate. The available methods have one or the other limitations which pose challenges for the downstream analysis. Hence, integration of different methods is the most effective way to isolate exosomes with high recovery rate, purity and intact biological functions that open new avenues for exploring the therapeutic potential of MDE improving health and developing innovative medical interventions.

Isolation and Characterization of Exosomes Derived from Mouse Spleen Tissues.

Exosomes (Exo) are lipid-bilayer structures secreted by various cells, including those of animals, plants, and prokaryotes. Previous studies have revealed that Exo derived from humoral or cell-supernatant are promising targets for novel diagnostic or prognostic biomarkers, underscoring their significant role in disease pathogenesis. Tissue-derived Exo (Ti-Exo) have attracted increasing attention due to its ability to accurately reflect tissue specificity and the microenvironment. Ti-Exo, present in interstitial space, play crucial roles in intercellular communication and cross-organ signaling. Despite their recognized value in elucidating disease mechanisms, isolating Ti-Exo remains challenging due to the complexity of tissue matrices and variability in extraction methods. In this study, we developed a practical protocol for isolating exosomes from mice spleen tissue, providing a reproducible technique for subsequent identification analysis and functional studies. We used Type I collagenase digestion combined with differential ultracentrifugation to isolate spleen-derived Exo. The characteristics of isolated Exo were determined through electron microscopy, the nano-flow cytometer, and the western blot. The isolated spleen-derived Exo displayed the typical morphology of lipid bilayer vesicles, with particle sizes ranging from 30 nm to 150 nm. In addition, the expression profile of exosome markers confirmed the presence and purity of exosomes. Taken together, we successfully established a practical protocol for isolating spleen-derived Exo in mice.

A biocompatible nanoformulation of curcumin analogue and curd exosomes targeting EphA2 signalling cascade in head and neck cancer

BackgroundMajor therapeutic developments have been made in the prevention of head and neck cancer (HNC), and crucial measures have been implemented for the survival of patients. The advent of cancer nano-theranostic as an effective approach targets cancer by allowing drug aggregation at the tumour site, its proper bioaccessibility, and tumour cell death. Curd exosomes are the cellular interactive nanovesicles, considered a convenient conveyance medium for cargoes still unexplored. Curcumin analogue alanine is primarily recognised for its superior radical scavenging activity and anti-mutagen properties compared with curcumin.MethodsThe current study focussed on the isolation and characterisation of curd exosomes, followed by their interaction with cancer cells to deliver their content conveniently. Herein, we developed a nanoformulation of curd exosomes loaded with curcumin alanine to determine its bioaccessibility and anti-proliferative effect compared with curcumin alanine free drug. In addition, the influence of curcumin alanine and its nanoformulation on cell morphology, nucleus structures, colony formation potential, and tumour cell death was observed. The expression of EphA2 and its associated molecules was determined using western blot and PCR to explore the mechanism at the cellular level.ResultsThe recent investigation revealed the encapsulation of curcumin analogue alanine in curd exosomes enhanced the bioaccessibility in contrast with curcumin alanine. Then, we focussed on the curcumin alanine effect on HNC cells to monitor morphological alterations, a reduction in cell multiplication, and triggering apoptosis. Particularly, we found considerable suppression of EphA2 influencing mitochondrial dynamics with the strengthening of mitochondrial fusion MFN1 and MFN2, whereas fission-associated protein DRP1 was down-regulated by the treatment of curcumin alanine nanoformulation. Furthermore, curcumin alanine nanoformulation activates the apoptotic marker caspase-7 and suppresses the anti-apoptotic marker Bcl-xL.ConclusionHence, these findings have drawn attention to curd exosomes loaded curcumin alanine nanoformulation impairing cell multiplication and mitochondrial fission, leading to apoptotic cell death, as one of the effective approaches for the treatment of HNC.Graphical

Surface protein analysis of breast cancer exosomes using visualized strategy on centrifugal disk chip

Breast cancer, the most common cancer among women worldwide, lacks specific tumor markers for accurate diagnosis. Recent advances have highlighted tumor-derived exosomes as a promising non-invasive biomarker for cancer detection. Continuous monitoring of surface protein markers on exosomes in the blood could offer valuable insights for breast cancer diagnosis. However, integrating the isolation and detection of exosomes from whole blood is bulky, time-consuming, and requires professional operations. To address this difficulty, we developed a method of integrated centrifugal disk chip (CD chip) exosome enrichment directly from whole blood followed by a colorimetric visualization strategy for multiplex analysis. The disc consists of multi-chambers and multi-microchannels with immediate smartphone-enabled processing of colorimetric results. The combination of CEA + CA125 + EGFR on-chip detection could significantly differentiate the different stages of cancer in tumor-bearing mice and successfully distinguish between breast cancer patients and healthy individuals. Crucially, small volumes (100 μL) of blood samples were adequate. In addition, the chip was simple and fast, with results within 10 min, which provides immediate exosomal information through consecutive blood sampling, which could potentially result in a more timely and well-informed clinical breast cancer diagnosis.

Isolation and quantification of human urinary exosomes using a Tween-20 elution solvent from polyester, capillary-channeled polymer fiber columns

BackgroundExosomes, a subset of extracellular vesicles (EVs), are a type of membrane-secreted vesicle essential for intercellular communication. There is a great deal of interest in developing methods to isolate and quantify exosomes to study their role in intercellular processes and as potential therapeutic delivery systems. Polyester, capillary-channeled polymer fiber columns and spin-down tips are highly efficient, low-cost means of exosome isolation. As the methodology evolves, there remain questions as to the optimum elution solvent for specific end-uses of the recovered vesicles; fundamental biochemistry, clinical diagnostics, or therapeutic vectors. ResultsWhile both acetonitrile and glycerol have been proven highly successful in terms of EV recoveries in the hydrophobic interaction chromatography workflow, many biological studies entail the use of the non-ionic detergent, Tween-20, as a working solvent. Here we evaluate the use of Tween-20 as the elution solvent for the recovery of exosomes. A novel 10-min, two-step gradient elution method, employing 0.1 % v/v Tween-20, efficiently isolated EVs at a concentration of ∼1011 EV mL−1 from a 100 μL urine injection. Integration of absorbance and multi-angle light scattering detectors in standard HPLC instrumentation enables a comprehensive single-injection determination of eluted exosome concentration and sizes. Transmission electron microscopy verifies the retention of the vesicular structure of the exosomes. The micro-bicinchoninic acid protein quantification assay confirmed high-purity isolations of exosomes (∼99 % removal of background proteins) SignificanceThe effective use of Tween-20 as an elution solvent for exosome isolation/purification using capillary-channeled polymer fiber columns adds greater versatility to the portfolio of the approach. The proposed method holds promise for a wide range of fundamental biochemistry, clinical diagnostics, and therapeutic applications, marking a significant advancement in EV-based methodologies.

In vitro Chondrogenic Induction Promotes the Expression Level of IL-10 via the TGF-β/SMAD and Canonical Wnt/β-catenin Signaling Pathways in Exosomes Secreted by Human Adipose Tissue-derived Mesenchymal Stem Cells.

Current treatment approaches cannot exactly regenerate cartilage tissue. Regarding some problems encountered with cell therapy, exosomes are advantageous because of their "cell-free" nature. This study examines the relationship between IL-10 and TGF-β and Canonical Wnt/β-catenin signal pathways in human adipose tissue-derived MSCs exosomes (hAT-MSCs-Exos) after in vitro chondrogenic differentiation. Human adipose tissue-derived mesenchymal stem cells (hAT-MSCs) and, as a control group, human fetal chondroblast cells (hfCCs) were differentiated chondrogenically in vitro. Exosome isolation and characterization analyses were performed. Chondrogenic differentiation was shown by Alcian Blue and Safranin O stainings. The expression levels of IL-10, TGF-β/SMAD signaling pathway genes, and Canonical Wnt/β-catenin signaling pathway genes, which play an essential role in chondrogenesis, were analyzed by RT-qPCR. Conditioned media cytokine levels were measured by using the TGF-β and IL-10 ELISA kits. IL-10 expression was upregulated in both chondrogenic differentiated hAT-MSC-Exos (dhAT-MSC-Exos) (p < 0.0001). In the TGF-β signaling pathway, TGF-β (p < 0.0001), SMAD2 (p < 0.0001), SMAD4 (p < 0.001), ACAN (p < 0.0001), SOX9 (p < 0.05) and COL1A2 (p < 0.0001) expressions were upregulated in dhAT-MSC-Exos. SMAD3 expression was upregulated in non-differentiated hAT-MSC-Exos. In the Canonical Wnt/β-catenin signaling pathway, WNT (p < 0.0001) and CTNNB1(p < 0.0001) expressions were upregulated in dhAT-MSC-Exos. AXIN (p < 0.0001) expression was upregulated in non-differentiated hAT-MSC-Exos. TGF-β and IL-10 levels were higher in dhAT-MSCs) (p < 0.0001). Related to these results, IL-10 may induce TGF-β/SMAD and Canonical Wnt/β-catenin signaling pathways in hAT-MSC exosomes obtained after chondrogenic differentiation. Therefore, using these exosomes for cartilage regeneration can lead to the development of treatment methods.

ISOLATION OF THE EXOSOMES FROM hUC-MSCs

The studies on the potential application of exosomes isolated from stem cells are expanding every year. Researchers and medical clinics are interested in them in the regard that exosomes contain different molecules that have therapeutic and regeneration potential. This study aimed to investigate the exosomes of human umbilical cord-derived mesenchymal stem cells (hUC-MSCs). The hUC-MSCs were isolated from the human umbilical cord using the standard protocol. Obtained cells were cultivated till 3rd passage. Then, the conditioned medium (CM) was collected, centrifuged and ultracentrifuged using the standard protocol for exosome isolation. The isolated exosomes were identified in 63 x magnification in the inverted microscope and the concentration of DNA and RNA was measured by nanodrope equipment. The obtained hUC-MSCs showed typical morphology of MSCs. We isolated exosomes from the CM of UC-MSCs. The obtained exosomes were round-shaped and had a distinct border. The DNA concentration and RNA concentration in obtained exosomes were 13.4 ng/ml and 17.0 ng/ml, respectively. Our hUC-MSCs-derived exosomes demonstrated the initial characteristics of normal exosomes and also contained DNA and RNA. Further study is needed to determine their functional properties.