Advances in exosomes technology

Mesenchymal stem cell-derived extracellular vesicles in joint diseases: Therapeutic effects and underlying mechanisms

Joint diseases greatly impact the daily lives and occupational functioning of patients globally. However, conventional treatments for joint diseases have several limitations, such as unsatisfatory efficacy and side effects, necessitating the exploration of more efficacious therapeutic strategies. Mesenchymal stem cell (MSC)-derived EVs (MSC-EVs) have demonstrated high therapeutic efficacyin tissue repair and regeneration, with low immunogenicity and tumorigenicity. Recent studies have reported that EVs-based therapy has considerable therapeutic effects against joint diseases, including osteoarthritis, tendon and ligament injuries, femoral head osteonecrosis, and rheumatoid arthritis. Herein, we review the therapeutic potential of various types of MSC-EVs in the aforementioned joint diseases, summarise the mechanisms underlying specific biological effects of MSC-EVs, and discuss future prospects for basic research on MSC-EV-based therapeutic modalities and their clinical translation. In general, this review provides an in-depth understanding of the therapeutic effects of MSC-EVs in joint diseases, as well as the underlying mechanisms, which may be beneficial to the clinical translation of MSC-EV-based treatment. The translational potential of this article: MSC-EV-based cell-free therapy can effectively promote regeneration and tissue repair. When used to treat joint diseases, MSC-EVs have demonstrated desirable therapeutic effects in preclinical research. This review may supplement further research on MSC-EV-based treatment of joint diseases and its clinical translation.

Exploring novel circulating biomarkers for liver cancer through extracellular vesicle characterization with infrared spectroscopy and plasmonics

BACKGROUND

Hepatocellular carcinoma (HCC) is the most common form of liver cancer, with cirrhosis being a major risk factor. Traditional blood markers like alpha-fetoprotein (AFP) demonstrate limited efficacy in distinguishing between HCC and cirrhosis, underscoring the need for more effective diagnostic methodologies. In this context, extracellular vesicles (EVs) have emerged as promising candidates; however, their practical diagnostic application is restricted by the current lack of label-free methods to accurately profile their molecular content. To address this gap, our study explores the potential of mid-infrared (mid-IR) spectroscopy, both alone and in combination with plasmonic nanostructures, to detect and characterize circulating EVs.

RESULTS

EVs were extracted from HCC and cirrhotic patients. Mid-IR spectroscopy in the Attenuated Total Reflection (ATR) mode was utilized to identify potential signatures for patient classification, highlighting significant changes in the Amide I-II region (1475-1700 cm-1). This signature demonstrated diagnostic performance comparable to AFP and surpassed it when the two markers were combined. Further investigations utilized a plasmonic metasurface suitable for ultrasensitive spectroscopy within this spectral range. This device consists of two sets of parallel rod-shaped gold nanoantennas (NAs); the longer NAs produced an intense near-field amplification in the Amide I-II bands, while the shorter NAs were utilized to provide a sharp reflectivity edge at 1800-2200 cm-1 for EV mass-sensing. A clinically relevant subpopulation of EVs was targeted by conjugating NAs with an antibody specific to Epithelial Cell Adhesion Molecule (EpCAM). This methodology enabled the detection of variations in the quantity of EpCAM-presenting EVs and revealed changes in the Amide I-II lineshape.

SIGNIFICANCE

The presented results can positively impact the development of novel laboratory methods for the label-free characterization of EVs, based on the combination between mid-IR spectroscopy and plasmonics. Additionally, data obtained by using HCC and cirrhotic subjects as a model system, suggest that this approach could be adapted for monitoring these conditions.

Future embracing: exosomes driving a revolutionary approach to the diagnosis and treatment of idiopathic membranous nephropathy

Membranous nephropathy (MN) is a leading cause of nephrotic syndrome in adults and is associated with high rates of end-stage renal disease. Early detection and precise interventions are crucial for improving patient prognosis and quality of life. However, the current diagnosis primarily relies on renal biopsies and traditional biomarkers, which have limitations. Additionally, targeted therapeutic strategies are lacking. Exosomes, small vesicles that facilitate intercellular communication, have emerged as potential noninvasive diagnostic markers due to their stability, diverse cargo, and rapid detectability. They also hold promise as carriers for gene and drug delivery, presenting innovative opportunities in renal disease prognosis and treatment. However, research on exosomes in the context of idiopathic membranous nephropathy (IMN) remains limited, with a focus on exploring urinary exosomes as IMN markers. In this review, we summarize the current status of MN diagnosis and treatment, highlight the fundamental characteristics of exosomes, and discuss recent advancements in their application to IMN diagnosis and therapy. We provide insights into the clinical prospects of exosomes in IMN and acknowledge potential challenges. This article aims to offer forward-looking insights into the future of exosome-mediated IMN diagnosis and treatment, indicating a revolutionary transformation in this field.

Studying the small extracellular vesicle capture efficiency of magnetic beads coated with tannic acid

The isolation of small extracellular vesicles (sEVs), including those secreted by pathological cells, with high efficiency and purity is highly demanded for research studies and practical applications. Conventional sEV isolation methods suffer from low yield, presence of contaminants, long-term operation and high costs. Bead-assisted platforms are considered to be effective for trapping sEVs with high recovery yield and sufficient purity for further molecular profiling. In this study, magnetically responsive beads made of calcium carbonate (CaCO3) particles impregnated with iron oxide (Fe3O4) nanoparticles are fabricated using a freezing-induced loading (FIL) method. The developed magnetic beads demonstrate sufficient magnetization and can be collected by a permanent magnet, ensuring their rapid and gentle capture from an aqueous solution. The tannic acid on the surface of magnetic beads is formed by a layer-by-layer (LbL) method and is used to induce coupling of sEVs with the surface of magnetic beads. These tannic acid coated magnetic beads (TAMB) were applied to capture sEVs derived from MCF7 and HCT116 cell lines. Quantitative data derived from nanoparticle tracking analysis (NTA) and BCA methods revealed the capture efficiency and recovery yield of about 60%. High-resolution transmission electron microscopy (HRTEM) imaging of sEVs on the surface of TAMBs indicated their structural integrity. Compared with the size exclusion chromatography (SEC) method, the proposed approach demonstrated comparable efficiency in terms of recovery yield and purity, while offering a relatively short operation time. These results highlight the high potential of the TAMB approach for the enrichment of sEVs from biological fluids, such as cell culture media.

Exosome Isolation Using Chitosan Oligosaccharide Lactate-1-Pyrenecarboxylic Acid-Based Self-Assembled Magnetic Nanoclusters

Exosomes are small extracellular vesicles that play a crucial role in intercellular communication and offer significant potential for a wide range of biomedical applications. However, conventional methods for exosome isolation have limitations in terms of purity, scalability, and preservation of exosome structural integrity. To address these challenges, an exosome isolation platform using chitosan oligosaccharide lactate conjugated 1-pyrenecarboxylic acid (COL-Py) based self-assembled magnetic nanoclusters (CMNCs), is presented. CMNCs are characterized to optimize their size, stability, and interaction dynamics with exosomes. The efficiency of CMNCs in isolating exosomes is systematically evaluated using various analytical methods to demonstrate their ability to capture exosomes based on amphiphilic lipid bilayers. CMNC-based exosome isolation consistently yields exosomes with structural integrity and purity similar to those obtained using traditional methods. The reusability of CMNCs over multiple exosome isolation cycles underscores their scalability and offers an efficient solution for biomedical applications. These results are supported by western blot analysis, which demonstrated the superiority of CMNC-based isolation in terms of purity compared to conventional methods. By providing a scalable and efficient exosome isolation process that preserves both structural integrity and purity, CMNCs can constitute a new platform that can contribute to the field of exosome studies.

miR-451a was selectively sorted into exosomes and promoted the progression of esophageal squamous cell carcinoma through CAB39

Exosomes are emerging mediators of cell-cell communication, which are secreted from cells and may be delivered into recipient cells in cell biological processes. Here, we examined microRNA (miRNA) expression in esophageal squamous cell carcinoma (ESCC) cells. We performed miRNA sequencing in exosomes and cells of KYSE150 and KYSE450 cell lines. Among these differentially expressed miRNAs, 20 of the miRNAs were detected in cells and exosomes. A heat map indicated that the level of miR-451a was higher in exosomes than in ESCC cells. Furthermore, miRNA pull-down assays and combined exosomes proteomic data showed that miR-451a interacts with YWHAE. Over-expression of YWHAE leads to miR-451a accumulation in the exosomes instead of the donor cells. We found that miR-451a was sorted into exosomes. However, the biological function of miR-451a remains unclear in ESCC. Here, Dual-luciferase reporter assay was conducted and it was proved that CAB39 is a target gene of miR-451a. Moreover, CAB39 is related to TGF-β1 from RNA-sequencing data of 155 paired of ESCC tissues and the matched tissues. Western Blot and qPCR revealed that CAB39 and TGF-β1 were positively correlated in ESCC. Over-expression of CAB39 were cocultured with PBMCs from the blood from healthy donors. Flow cytometry assays showed that apoptotic cells were significantly reduced after CAB39 over-expression and significantly increased after treated with TGF-β1 inhibitors. Thus, our data indicate that CAB39 weakens antitumor immunity through TGF-β1 in ESCC. In summary, YWHAE selectively sorted miR-451a into exosomes and it can weaken antitumor immunity promotes tumor progression through CAB39.

The Exosome-Mediated Bone Regeneration: An Advanced Horizon Toward the Isolation, Engineering, Carrying Modalities, and Mechanisms

Exosomes, nanoparticles secreted by various cells, composed of a bilayer lipid membrane, and containing bioactive substances such as proteins, nucleic acids, metabolites, etc., have been intensively investigated in tissue engineering owing to their high biocompatibility and versatile biofunction. However, there is still a lack of a high-quality review on bone defect regeneration potentiated by exosomes. In this review, the biogenesis and isolation methods of exosomes are first introduced. More importantly, the engineered exosomes of the current state of knowledge are discussed intensively in this review. Afterward, the biomaterial carriers of exosomes and the mechanisms of bone repair elucidated by compelling evidence are presented. Thus, future perspectives and concerns are revealed to help devise advanced modalities based on exosomes to overcome the challenges of bone regeneration. It is totally believed this review will attract special attention from clinicians and provide promising ideas for their future works.

Unveiling the Complex Role of Exosomes in Alzheimer's Disease

Alzheimer's disease (AD) is the most common neurodegenerative illness, characterized by memory loss and cognitive decline, accounting for 60-80% of dementia cases. AD is characterized by senile plaques made up of amyloid β (Aβ) protein, intracellular neurofibrillary tangles caused by hyperphosphorylation of tau protein linked with microtubules, and neuronal loss. Currently, therapeutic treatments and nanotechnological developments are effective in treating the symptoms of AD, but a cure for the illness has not yet been found. Recently, the increased study of extracellular vesicles (EVs) has led to a growing awareness of their significant involvement in neurodegenerative disorders, including AD. Exosomes are small extracellular vesicles that transport various components including messenger RNAs, non-coding RNAs, proteins, lipids, DNA, and other bioactive compounds from one cell to another, facilitating information transmission and material movement. There is growing evidence indicating that exosomes have complex functions in AD. Exosomes may have a dual role in Alzheimer's disease by contributing to neuronal death and also helping to alleviate the pathological progression of the disease. Therefore, the primary aim of this review is to outline the updated understandings on exosomes biogenesis and many functions of exosomes in the generation, conveyance, distribution, and elimination of hazardous proteins related to Alzheimer's disease. This review is intended to provide novel insights for understanding the development, specific treatment, and early detection of Alzheimer's disease.

A comprehensive guide to extract information from extracellular vesicles: a tutorial review towards novel analytical developments

In the medical field, extracellular vesicles (EVs) are gaining importance as they act as cells mediators. These are phospholipid bilayer vesicles and contain crucial biochemical information about their mother cells being carrier of different biomolecules such as small molecules, proteins, lipids, and nucleic acids. After release into the extracellular matrix, they enter the systemic circulation and can be found in all human biofluids. Since EVs reflect the state of the cell of origin, there is exponential attention as potential source of new circulating biomarkers for liquid biopsy. The use of EVs in clinical practice faces several challenges that need to be addressed: these include the standardization of lysis protocols, the availability of low-cost reagents and the development of analytical tools capable of detecting biomarkers. The process of lysis is a crucial step that can impact all subsequent analyses, towards the development of novel analytical strategies. To aid researchers to support the evolution of measurement science technology, this tutorial review evaluates and discuss the most commonly protocols used to characterize the contents of EVs, including their advantages and disadvantages in terms of experimental procedures, time and equipment. The purpose of this tutorial review is to offer practical guide to researchers which are intended to develop novel analytical approaches. Some of the most significant applications are considered, highlighting their main characteristics divided per mechanism of action. Finally, comprehensive tables which provide an overview at a glance are provided to readers.

Unlocking the potential of exosomes: a breakthrough in the theranosis of degenerative orthopaedic diseases

Degenerative orthopaedic diseases pose a notable worldwide public health issue attributable to the global aging population. Conventional medical approaches, encompassing physical therapy, pharmaceutical interventions, and surgical methods, face obstacles in halting or reversing the degenerative process. In recent times, exosome-based therapy has gained widespread acceptance and popularity as an effective treatment for degenerative orthopaedic diseases. This therapeutic approach holds the potential for "cell-free" tissue regeneration. Exosomes, membranous vesicles resulting from the fusion of intracellular multivesicles with the cell membrane, are released into the extracellular matrix. Addressing challenges such as the rapid elimination of natural exosomes in vivo and the limitation of drug concentration can be effectively achieved through various strategies, including engineering modification, gene overexpression modification, and biomaterial binding. This review provides a concise overview of the source, classification, and preparation methods of exosomes, followed by an in-depth analysis of their functions and potential applications. Furthermore, the review explores various strategies for utilizing exosomes in the treatment of degenerative orthopaedic diseases, encompassing engineering modification, gene overexpression, and biomaterial binding. The primary objective is to provide a fresh viewpoint on the utilization of exosomes in addressing bone degenerative conditions and to support the practical application of exosomes in the theranosis of degenerative orthopaedic diseases.

Hypoxia-Challenged Pancreatic Adenocarcinoma Cell-Derived Exosomal circR3HCC1L Drives Tumor Growth Via Upregulating PKM2 Through Sequestering miR-873-5p

Pancreatic adenocarcinoma (PAAD) is a fatal disease with poor survival. Increasing evidence show that hypoxia-induced exosomes are associated with cancer progression. Here, we aimed to investigate the function of hsa_circ_0007678 (circR3HCC1L) and hypoxic PAAD cell-derived exosomal circR3HCC1L in PAAD progression. Through the exoRBase 2.0 database, we screened for a circular RNA circR3HCC1L related to PAAD. Changes of circR3HCC1L in PAAD samples and cells were analyzed with real-time quantitative polymerase chain reaction (RT-qPCR). Cell proliferation, migration, invasion were analyzed by colony formation, cell counting, and transwell assays. Measurements of glucose uptake and lactate production were done using corresponding kits. Several protein levels were detected by western blotting. The regulation mechanism of circR3HCC1L was verified by dual-luciferase reporter, RNA immunoprecipitation, and RNA pull-down assays. Exosomes were separated by differential ultracentrifugation. Animal experiments were used to verify the function of hypoxia-derived exosomal circR3HCC1L. CircR3HCC1L was upregulated in PAAD samples and hypoxic PAAD cells. Knockdown of circR3HCC1L decreased hypoxia-driven PAAD cell proliferation, migration, invasion, and glycolysis. Hypoxic PAAD cell-derived exosomes had higher levels of circR3HCC1L, hypoxic PAAD cell-derived exosomal circR3HCC1L promoted normoxic cancer cell malignant transformation and glycolysis in vitro and xenograft tumor growth in mouse models in vivo. Mechanistically, circR3HCC1L regulated pyruvate kinase M2 (PKM2) expression via sponging miR-873-5p. Also, PKM2 overexpression or miR-873-5p silencing offset circR3HCC1L knockdown-mediated effects on hypoxia-challenged PAAD cell malignant transformation and glycolysis. Hypoxic PAAD cell-derived exosomal circR3HCC1L facilitated PAAD progression through the miR-873-5p/PKM2 axis, highlighting the contribution of hypoxic PAAD cell-derived exosomal circR3HCC1L in PAAD.

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

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

Non-stem cell-derived exosomes: a novel therapeutics for neurotrauma

Neurotrauma, encompassing traumatic brain injuries (TBI) and spinal cord injuries (SCI) impacts a significant portion of the global population. While spontaneous recovery post-TBI or SCI is possible, recent advancements in cell-based therapies aim to bolster these natural reparative mechanisms. Emerging research indicates that the beneficial outcomes of such therapies might be largely mediated by exosomes secreted from the administered cells. While stem cells have garnered much attention, exosomes derived from non-stem cells, including neurons, Schwann cells, microglia, and vascular endothelial cells, have shown notable therapeutic potential. These exosomes contribute to angiogenesis, neurogenesis, and axon remodeling, and display anti-inflammatory properties, marking them as promising agents for neurorestorative treatments. This review provides an in-depth exploration of the current methodologies, challenges, and future directions regarding the therapeutic role of non-stem cell-derived exosomes in neurotrauma.

Osteogenically committed hUCMSCs-derived exosomes promote the recovery of critical-sized bone defects with enhanced osteogenic properties

Low viability of seed cells and the concern about biosafety restrict the application of cell-based tissue-engineered bone (TEB). Exosomes that bear similar bioactivities to donor cells display strong stability and low immunogenicity. Human umbilical cord mesenchymal stem cells-derived exosomes (hUCMSCs-Exos) show therapeutic efficacy in various diseases. However, little is known whether hUCMSCs-Exos can be used to construct TEB to repair bone defects. Herein, PM-Exos and OM-Exos were separately harvested from hUCMSCs which were cultured in proliferation medium (PM) or osteogenic induction medium (OM). A series of in-vitro studies were performed to evaluate the bioactivities of human bone marrow mesenchymal stem cells (hBMSCs) when co-cultured with PM-Exos or OM-Exos. Differential microRNAs (miRNAs) between PM-Exos and OM-Exos were sequenced and analyzed. Furthermore, PM-Exos and OM-Exos were incorporated in 3D printed tricalcium phosphate scaffolds to build TEBs for the repair of critical-sized calvarial bone defects in rats. Results showed that PM-Exos and OM-Exos bore similar morphology and size. They expressed representative surface markers of exosomes and could be internalized by hBMSCs to promote cellular migration and proliferation. OM-Exos outweighed PM-Exos in accelerating the osteogenic differentiation of hBMSCs, which might be attributed to the differentially expressed miRNAs. Furthermore, OM-Exos sustainably released from the scaffolds, and the resultant TEB showed a better reparative outcome than that of the PM-Exos group. Our study found that exosomes isolated from osteogenically committed hUCMSCs prominently facilitated the osteogenic differentiation of hBMSCs. TEB grafts functionalized by OM-Exos bear a promising application potential for the repair of large bone defects.

Small extracellular vesicles purification and scale-up

Exosomes are small extracellular vesicles (sEVs) secreted by cells. With advances in the study of sEVs, they have shown great potential in the diagnosis and treatment of disease. However, sEV therapy usually requires a certain dose and purity of sEVs to achieve the therapeutic effect, but the existing sEV purification technology exists in the form of low yield, low purity, time-consuming, complex operation and many other problems, which greatly limits the application of sEVs. Therefore, how to obtain high-purity and high-quality sEVs quickly and efficiently, and make them realize large-scale production is a major problem in current sEV research. This paper discusses how to improve the purity and yield of sEVs from the whole production process of sEVs, including the upstream cell line selection and cell culture process, to the downstream isolation and purification, quality testing and the final storage technology.

DNA Logical Device Combining an Entropy-Driven Catalytic Amplification Strategy for the Simultaneous Detection of Exosomal Multiplex miRNAs In Situ

Exosomal miRNAs are considered promising biomarkers for cancer diagnosis, but their accuracy is severely compromised by the low content of miRNAs and the large amount of exosomal miRNAs released from normal cells. Here, we presented a dual-specific miRNA's logical recognition triggered by an entropy-driven catalysis (EDC)-enhanced system in exosomes for accurate detection of liver cancer-cell-derived exosomal miR-21 and miR-122. Taking advantage of the accurate analytical performance of the logic device, the excellent membrane penetration of gold nanoparticles, and the outstanding amplification ability of the EDC reaction, this method exhibits high sensitivity and selectivity for the detection of tumor-derived exosomal miRNAs in situ. Moreover, due to its excellent performance, this logic device can effectively distinguish liver cancer patients from healthy donors by determining the amount of cancer-cell-derived exosomal miRNAs. Overall, this strategy has great potential for analyzing various types of exosomes and provides a viable tool to improve the accuracy of cancer diagnosis.

Advancements in Mid-Infrared spectroscopy of extracellular vesicles

Extracellular vesicles (EVs) are lipid vesicles secreted by all cells into the extracellular space and act as nanosized biological messengers among cells. They carry a specific molecular cargo, composed of lipids, proteins, nucleic acids, and carbohydrates, which reflects the state of their parent cells. Due to their remarkable structural and compositional heterogeneity, characterizing EVs, particularly from a biochemical perspective, presents complex challenges. In this context, mid-infrared (IR) spectroscopy is emerging as a valuable tool, providing researchers with a comprehensive and label-free spectral fingerprint of EVs in terms of their specific molecular content. This review aims to provide an up-to-date critical overview of the major advancements in mid-IR spectroscopy of extracellular vesicles, encompassing both fundamental and applied research achievements. We also systematically emphasize the new possibilities offered by the integration of emerging cutting-edge IR technologies, such as tip-enhanced and surface-enhanced spectroscopy approaches, along with the growing use of machine learning for data analysis and spectral interpretation. Additionally, to assist researchers in navigating this intricate subject, our manuscript includes a wide and detailed collection of the spectral peaks that have been assigned to EV molecular constituents up to now in the literature.

Orange-spotted grouper nervous necrosis virus-encoded protein A induces interferon expression via RIG-I/MDA5-MAVS-TBK1-IRF3 signaling in fish cells

IMPORTANCE

As a major pathogen, nervous necrosis virus (NNV) infects more than 120 fish species worldwide and is virulent to larvae and juvenile fish, hampering the development of the fish fry industry. Understanding virus-host interaction and underlying mechanisms is an important but largely unknown issue in fish virus studies. Here, using channel catfish ovary and fathead minnow cells as models for the study of innate immunity signaling, we found that NNV-encoded ProA activated interferon signaling via the retinoic acid-inducible gene I (RIG-I)-like receptor (RLR) pathway which was still suppressed by the infection of wild-type NNV. This finding has important implications for the comprehension of NNV protein function and the immune response from different cells. First, RIG-I is the key node for anti-NNV innate immunity. Second, the response intensity of RLR signaling determines the degree of NNV proliferation. This study expands our knowledge regarding the overview of signal pathways affected by NNV-encoded protein and also highlights potential directions for the control of aquatic viruses.

Prostate cancer-derived small extracellular vesicle proteins: the hope in diagnosis, prognosis, and therapeutics

Current diagnostic tools for prostate cancer (PCa) diagnosis and risk stratification are insufficient. The hidden onset and poor efficacy of traditional therapies against metastatic PCa make this disease a heavy burden in global men's health. Prostate cancer-derived extracellular vesicles (PCDEVs) have garnered attention in recent years due to their important role in communications in tumor microenvironment. Recent advancements have demonstrated PCDEVs proteins play an important role in PCa invasion, progression, metastasis, therapeutic resistance, and immune escape. In this review, we briefly discuss the applications of sEV proteins in PCa diagnosis and prognosis in liquid biopsy, focus on the roles of the PCa-derived small EVs (sEVs) proteins in tumor microenvironment associated with cancer progression, and explore the therapeutic potential of sEV proteins applied for future metastatic PCa therapy.

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

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

Engineered exosomes for tissue regeneration: from biouptake, functionalization and biosafety to applications

Exosomes are increasingly recognized as important effector molecules that regulate intercellular signaling pathways. Notably, certain types of exosomes can induce therapeutic responses, including cell proliferation, angiogenesis, and tissue repair. The use of exosomes in therapy is a hot spot in current research, especially in regenerative medicine. Despite the therapeutic potential, problems have hindered their success in clinical applications. These shortcomings include low concentration, poor targeting and limited loading capability. To fully realize their therapeutic potential, certain modifications are needed in native exosomes. In the present review, we summarize the exosome modification and functionalization strategies. In addition, we provide an overview of potential clinical applications and highlight the issues associated with the biosafety and biocompatibility of engineered exosomes in applications.

Extracellular vesicle biomarkers for prostate cancer diagnosis: A systematic review and meta-analysis

Extracellular vesicle (EV) biomarkers have promising diagnostic and screening capabilities for several cancers, and growing evidence indicates that EV biomarkers can be used as diagnostic markers for prostate cancer (CaP). However, data on the diagnostic accuracy of EV biomarkers for CaP diagnosis are conflicting. We performed a systematic review and meta-analysis, aimed to summarize the diagnostic performance of EV biomarkers for CaP. We systematically searched PubMed, Medline, and Web of Science from inception to 12 September 2022 for studies that assessed the diagnostic accuracy of EV biomarkers for CaP. We summarized the pooled sensitivity and specificity calculated using a random-effects model. We identified 19 studies involving 976 CaP patients and 676 noncancerous controls; one study conducted independent validation tests. Ten studies emphasized EV RNAs, 6 on EV proteins, and 9 on biomarker panels. MiR-141, miR-221, and PSMA were the most frequently reported RNAs and proteins for CaP diagnosis. For individual RNAs and proteins, the pooled sensitivity and specificity were 70% (95% CI: 68%-71%), 79% (95% CI: 77%-80%), 85% (95% CI: 81%-87%), and 83% (95% CI: 80%-86%), respectively. The pooled sensitivity and specificity of the EV panels were 84% (95% CI: 82%-86%) and 86% (95% CI: 84%-88%), respectively. The studies may have been somewhat limited by the EV isolation and detection techniques. EV biomarkers showed promising diagnostic capability for CaP. Addressing deficiencies in EV isolation and detection techniques has important implications for the application of these novel noninvasive biomarkers in clinical practice.

Lipid bilayer-based biological nanoplatforms for sonodynamic cancer therapy

Sonodynamic therapy (SDT) has been developed as a promising alternative therapeutic modality for cancer treatment, involving the synergetic application of sonosensitizers and low-intensity ultrasound. However, the antitumor efficacy of SDT is significantly limited due to the poor performance of conventional sonosensitizers in vivo and the constrained tumor microenvironment (TME). Recent breakthroughs in lipid bilayer-based nanovesicles (LBBNs), including multifunctional liposomes, exosomes, and isolated cellular membranes, have brought new insights into the advancement of SDT. Despite their distinct sources and preparation methods, the lipid bilayer structure in common allows them to be functionalized in many comparable ways to serve as ideal nanocarriers against challenges arising from the tumor-specific sonosensitizer delivery and the complicated TME. In this review, we provide a comprehensive summary of the recent advances in LBBN-based SDT, with particular attention on how LBBNs can be engineered to improve the delivery efficiency of sonosensitizers and overcome physical, biological, and immune barriers within the TME for enhanced sonodynamic cancer therapy. We anticipate that this review will offer valuable guidance in the construction of LBBN-based nanosonosensitizers and contribute to the development of advanced strategies for next-generation sonodynamic cancer therapy.

Exosomes in Cancer Progression and Therapy Resistance: Molecular Insights and Therapeutic Opportunities

The development of therapy resistance still represents a major hurdle in treating cancers, leading to impaired treatment success and increased patient morbidity. The establishment of minimally invasive liquid biopsies is a promising approach to improving the early diagnosis, as well as therapy monitoring, of solid tumors. Because of their manifold functions in the tumor microenvironment, tumor-associated small extracellular vesicles, referred to as exosomes, have become a subject of intense research. Besides their important roles in cancer progression, metastasis, and the immune response, it has been proposed that exosomes also contribute to the acquisition and transfer of therapy resistance, mainly by delivering functional proteins and RNAs, as well as facilitating the export of active drugs or functioning as extracellular decoys. Extensive research has focused on understanding the molecular mechanisms underlying the occurrence of resistance and translating these into strategies for early detection. With this review, we want to provide an overview of the current knowledge about the (patho-)biology of exosomes, as well as state-of-the-art methods of isolation and analysis. Furthermore, we highlight the role of exosomes in tumorigenesis and cancer treatment, where they can function as therapeutic agents, biomarkers, and/or targets. By focusing on their roles in therapy resistance, we will reveal new paths of exploiting exosomes for cancer diagnosis and treatment.

Engineered Exosomes as Theranostic Platforms for Cancer Treatment

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

Exosomes: a potential diagnostic and treatment modality in the quest for counteracting cancer

BACKGROUND

Exosomes are nanosized bio vesicles formed when multivesicular bodies and the plasma membrane merge and discharge into bodily fluids. They are well recognized for facilitating intercellular communication by transporting numerous biomolecules, including DNA, RNAs, proteins, and lipids, and have been implicated in varied diseases including cancer. Exosomes may be altered to transport a variety of therapeutic payloads, including as short interfering RNAs, antisense oligonucleotides, chemotherapeutic drugs, and immunological modulators, and can be directed to a specific target. Exosomes also possess the potential to act as a diagnostic biomarker in cancer, in addition to their therapeutic potential.

CONCLUSION

In this review, the physiological roles played by exosomes were summarized along with their biogenesis process. Different isolation techniques of exosomes including centrifugation-based, size-based, and polymer precipitation-based techniques have also been described in detail with a special focus on cancer therapeutic applications. The review also shed light on techniques of incubation of drugs with exosomes and their characterization methods covering the most advanced techniques. Myriad applications of exosomes in cancer as diagnostic biomarkers, drug delivery carriers, and chemoresistance-related issues have been discussed at length. Furthermore, a brief overview of exosome-based anti-cancer vaccines and a few prominent challenges concerning exosomal delivery have been concluded at the end.

Plant-Derived Exosome-Like Nanovesicles: Current Progress and Prospects

Exosomes are small extracellular vesicles, ranging in size from 30-150nm, which can be derived from various types of cells. In recent years, mammalian-derived exosomes have been extensively studied and found to play a crucial role in regulating intercellular communication, thereby influencing the development and progression of numerous diseases. Traditional Chinese medicine has employed plant-based remedies for thousands of years, and an increasing body of evidence suggests that plant-derived exosome-like nanovesicles (PELNs) share similarities with mammalian-derived exosomes in terms of their structure and function. In this review, we provide an overview of recent advances in the study of PELNs and their potential implications for human health. Specifically, we summarize the roles of PELNs in respiratory, digestive, circulatory, and other diseases. Furthermore, we have extensively investigated the potential shortcomings and challenges in current research regarding the mechanism of action, safety, administration routes, isolation and extraction methods, characterization and identification techniques, as well as drug-loading capabilities. Based on these considerations, we propose recommendations for future research directions. Overall, our review highlights the potential of PELNs as a promising area of research, with broad implications for the treatment of human diseases. We anticipate continued interest in this area and hope that our summary of recent findings will stimulate further exploration into the implications of PELNs for human health.

Neural stem cell-derived exosomal FTO protects neuron from microglial inflammatory injury by inhibiting microglia NRF2 mRNA m6A modification

Ischemic stroke (IS) can cause neuronal cell loss and function defects. Exosomes derived from neural stem cells (NSC-Exos) improve neural plasticity and promote neural function repair following IS. However, the potential mechanism remains unclear. In this study, NSC-Exos were characterized and co-cultured with microglia. We found that NSC-Exos increased NRF2 expression in oxygen-glucose deprivation/reoxygenation and LPS-induced microglia and converted microglia from M1 pro-inflammatory phenotype to M2 anti-inflammatory phenotype. NSC-Exos reduced m6A methylation modification of nuclear factor erythroid 2-related factor 2 (NRF2) mRNA via obesity-associated gene (FTO). Furthermore, NSC-Exos reduced the damage to neurons caused by microglia's inflammatory response. Finally, the changes in microglia polarization and neuron damage caused by FTO knockdown in NSE-Exos were attenuated by NRF2 overexpression in microglia. These findings revealed that NSC-Exos promotes NRF2 expression and M2 polarization of microglial via transferring FTO, thereby resulting in neuroprotective effects.

Modeling and optimization of parallelized immunomagnetic nanopore sorting for surface marker specific isolation of extracellular vesicles from complex media

The isolation of specific subpopulations of extracellular vesicles (EVs) based on their expression of surface markers poses a significant challenge due to their nanoscale size (< 800 nm), their heterogeneous surface marker expression, and the vast number of background EVs present in clinical specimens (1010-1012 EVs/mL in blood). Highly parallelized nanomagnetic sorting using track etched magnetic nanopore (TENPO) chips has achieved precise immunospecific sorting with high throughput and resilience to clogging. However, there has not yet been a systematic study of the design parameters that control the trade-offs in throughput, target EV recovery, and ability to discard background EVs in this approach. We combine finite-element simulation and experimental characterization of TENPO chips to elucidate design rules to isolate EV subpopulations from blood. We demonstrate the utility of this approach by reducing device background > 10× relative to prior published designs without sacrificing recovery of the target EVs by selecting pore diameter, number of membranes placed in series, and flow rate. We compare TENPO-isolated EVs to those of gold-standard methods of EV isolation and demonstrate its utility for wide application and modularity by targeting subpopulations of EVs from multiple models of disease including lung cancer, pancreatic cancer, and liver cancer.

Biogenesis, Isolation, and Detection of Exosomes and Their Potential in Therapeutics and Diagnostics

The increasing research and rapid developments in the field of exosomes provide insights into their role and significance in human health. Exosomes derived from various sources, such as mesenchymal stem cells, cardiac cells, and tumor cells, to name a few, can be potential therapeutic agents for the treatment of diseases and could also serve as biomarkers for the early detection of diseases. Cellular components of exosomes, several proteins, lipids, and miRNAs hold promise as novel biomarkers for the detection of various diseases. The structure of exosomes enables them as drug delivery vehicles. Since exosomes exhibit potential therapeutic applications, their efficient isolation from complex biological/clinical samples and precise real-time analysis becomes significant. With the advent of microfluidics, nano-biosensors are being designed to capture exosomes efficiently and rapidly. Herein, we have summarized the history, biogenesis, characteristics, functions, and applications of exosomes, along with the isolation, detection, and quantification techniques. The implications of surface modifications to enhance specificity have been outlined. The review also sheds light on the engineered nanoplatforms being developed for exosome detection and capture.

Natural killer cell-derived exosomes for cancer immunotherapy: innovative therapeutics art

Chimeric antigen receptor natural killer cells (CAR-NK) promote off-the-shelf cellular therapy for solid tumors and malignancy.However,, the development of CAR-NK is due to their immune surveillance uncertainty and cytotoxicity challenge was restricted. Natural killer cell-derived exosome (NK-Exo) combine crucial targeted cellular therapies of NK cell therapies with unique non-toxic Exo as a self-origin shuttle against cancer immunotherapy. This review study covers cytokines, adoptive (autologous and allogenic) NK immunotherapy, stimulatory and regulatory functions, and cell-free derivatives from NK cells. The future path of NK-Exo cytotoxicity and anti-tumor activity with considering non-caspase-independent/dependent apoptosis and Fas/FasL pathway in cancer immunotherapy. Finally, the significance and implication of NK-Exo therapeutics through combination therapy and the development of emerging approaches for the purification and delivery NK-Exo to severe immune and tumor cells and tissues were discussed in detail.

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.

Advances in development of exosomes for ophthalmic therapeutics

Exosomes contain multiple bioactive molecules and maintain the connection between cells. Recent advances in exosome-based therapeutics have witnessed unprecedented opportunities in treating ophthalmic diseases, including traumatic diseases, autoimmune diseases, chorioretinal diseases and others. Utilization of exosomes as delivery vectors to encapsulate both drugs and therapeutic genes could yield higher efficacy and avoid the unnecessary immune responses. However, exosome-based therapies also come with some potential ocular risks. In this review, we first present a general introduction to exosomes. Then we provide an overview of available applications and discuss their potential risks. Moreover, we review recently reported exosomes as delivery vectors for ophthalmic diseases. Finally, we put forward future perspectives to grapple with its translation and underlying issues.

Ultrasensitive detection of exosomes by microchip electrophoresis combining with triple amplification strategies

The analysis of exosomes is significant as they can be used for various pathophysiological processes, especially cancer related intercellular communication. Therefore, a convenient, reliable, and sensitive detection method is urgently needed. Strand displacement amplification (SDA) and catalytic hairpin assembly (CHA) are two kinds of effective isothermal nucleic acid amplification methods. In this article, an efficient quantitative MCE method for detecting human breast cancer cell (MCF-7) exosomes assisted by triple amplification strategies combining cholesterol probe (Chol-probe) with SDA-CHA was first developed. CD63 aptamer was immobilized on the avidin magnetic beads to specifically capture exosomes and then Chol-probe with high affinity was spontaneously inserted into the exosome membrane, which was the first step of amplification strategy to improve detection sensitivity. After magnetic separation, Chol-probe could complement ssDNA and trigger SDA, producing a large number of DNA sequences (Ta) to trigger CHA, achieving SDA-CHA amplification. Under optimal conditions, the detection limit (LOD) for MCF-7 exosomes was as low as 26 particle/μL (S/N = 3). This method provides an effective approach for sensitive and accurate quantification of tumor exosomes, and can be expected to detect exosomes in clinical samples.

Progress in Isolation and Molecular Profiling of Small Extracellular Vesicles via Bead-Assisted Platforms

Tremendous interest in research of small extracellular vesicles (sEVs) is driven by the participation of vesicles in a number of biological processes in the human body. Being released by almost all cells of the body, sEVs present in complex bodily fluids form the so-called intercellular communication network. The isolation and profiling of individual fractions of sEVs secreted by pathological cells are significant in revealing their physiological functions and clinical importance. Traditional methods for isolation and purification of sEVs from bodily fluids are facing a number of challenges, such as low yield, presence of contaminants, long-term operation and high costs, which restrict their routine practical applications. Methods providing a high yield of sEVs with a low content of impurities are actively developing. Bead-assisted platforms are very effective for trapping sEVs with high recovery yield and sufficient purity for further molecular profiling. Here, we review recent advances in the enrichment of sEVs via bead-assisted platforms emphasizing the type of binding sEVs to the bead surface, sort of capture and target ligands and isolation performance. Further, we discuss integration-based technologies for the capture and detection of sEVs as well as future research directions in this field.

Small extracellular vesicles: a novel drug delivery system for neurodegenerative disorders

Neurodegenerative diseases (NDs) have a slow onset and are usually detected late during disease. NDs are often difficult to cure due to the presence of the blood-brain barrier (BBB), which makes it difficult to find effective treatments and drugs, causing great stress and financial burden to families and society. Currently, small extracellular vesicles (sEVs) are the most promising drug delivery systems (DDSs) for targeted delivery of molecules to specific sites in the brain as a therapeutic vehicle due to their low toxicity, low immunogenicity, high stability, high delivery efficiency, high biocompatibility and trans-BBB functionality. Here, we review the therapeutic application of sEVs in several NDs, including Alzheimer's disease, Parkinson's disease, and Huntington's disease, discuss the current barriers associated with sEVs and brain-targeted DDS, and suggest future research directions.

Rapid and simple isolation and detection of exosomes using CaTiO3:Eu3+@Fe3O4 multifunctional nanocomposites

Exosomes are potential biomarkers for disease diagnosis and treatment, as well as drug carriers. However, as their isolation and detection remain critical issues, convenient, rapid, low-cost, and effective methods are necessary. In this study, we present a rapid and simple method for directly capturing and analyzing exosomes from complex cell culture media using CaTiO₃:Eu³⁺@Fe₃O₄ multifunctional nanocomposites. The CaTiO₃:Eu³⁺@Fe₃O₄ nanocomposites were prepared by high-energy ball-milling and used to isolate exosomes by binding CaTiO₃:Eu³⁺@Fe₃O₄ nanocomposites and the hydrophilic phosphate head of the exosome phospholipids. Notably, the developed CaTiO₃:Eu³⁺@Fe₃O₄ multifunctional nanocomposites achieved results comparable with those of commercially available TiO₂ and were separated using a magnet within 10 min. Moreover, we report a surface-enhanced Raman scattering (SERS)-based immunoassay for detecting the exosome biomarker CD81. Gold nanorods (Au NRs) were modified with detection antibodies, and antibody-conjugated Au NRs were labeled with 3, 3, diethylthiatricarbocyanine iodide (DTTC) as the SERS tags. A method combining magnetic separation and SERS was developed to detect exosomal biomarker CD81. The results of this study demonstrate the feasibility of this new technique as a useful tool for exosome isolation and detection.

Exosomes: Promising Delivery Tools for Overcoming Blood-Brain Barrier and Glioblastoma Therapy

Gliomas make up virtually 80% of all lethal primary brain tumors and are categorized based on their cell of origin. Glioblastoma is an astrocytic tumor that has an inferior prognosis despite the ongoing advances in treatment modalities. One of the main reasons for this shortcoming is the presence of the blood-brain barrier and blood-brain tumor barrier. Novel invasive and non-invasive drug delivery strategies for glioblastoma have been developed to overcome both the intact blood-brain barrier and leverage the disrupted nature of the blood-brain tumor barrier to target cancer cells after resection-the first treatment stage of glioblastoma. Exosomes are among non-invasive drug delivery methods and have emerged as a natural drug delivery vehicle with high biological barrier penetrability. There are various exosome isolation methods from different origins, and the intended use of the exosomes and starting materials defines the choice of isolation technique. In the present review, we have given an overview of the structure of the blood-brain barrier and its disruption in glioblastoma. This review provided a comprehensive insight into novel passive and active drug delivery techniques to overcome the blood-brain barrier, emphasizing exosomes as an excellent emerging drug, gene, and effective molecule delivery vehicle used in glioblastoma therapy.

Tumor-Targeting Extracellular Vesicles Loaded with siS100A4 for Suppressing Postoperative Breast Cancer Metastasis

Introduction

S100A4 promotes the establishment of tumor microenvironment for malignant cancer cells, and knockdown of S100A4 can inhibit tumorigenesis. However, there is no efficient way to target S100A4 in metastatic tumor tissues. Here, we investigated the role of siS100A4-loaded iRGD-modified extracellular vesicles (siS100A4-iRGD-EVs) in postoperative breast cancer metastasis.

Methods

siS100A4-iRGD-EVs nanoparticles were engineered and analyzed using TEM and DLS. siRNA protection, cellular uptake, and cytotoxicity of EV nanoparticles were examined in vitro. Postoperative lung metastasis mouse model was created to investigate the tissue distribution and anti-metastasis roles of nanoparticles in vivo.

Results

siS100A4-iRGD-EVs protected siRNA from RNase degradation, enhanced the cellular uptake and compatibility in vitro. Strikingly, iRGD-modified EVs significantly increased tumor organotropism and siRNA accumulation in lung PMNs compared to siS100A4-EVs in vivo. Moreover, siS100A4-iRGD-EVs treatment remarkedly attenuated lung metastases from breast cancer and increased survival rate of mice through suppressing S100A4 expression in lung.

Conclusions

siS100A4-iRGD-EVs nanoparticles show more potent anti-metastasis effect in postoperative breast cancer metastasis mouse model.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12195-022-00757-5.

Tandem enrichment of serum exosomes and exosomal RNA with titanium dioxide

Exosomes have great potential as biomarker carriers for disease diagnosis and prognosis. In recent years, exosomal RNA (exoRNA) has become a promising candidate for the early diagnosis and prognosis of cancers, and its pathophysiological roles in various diseases have been revealed. For example, exosome-derived mRNAs, miRNAs, circRNAs, and lncRNAs function as signalling molecules to regulate tumour growth, angiogenesis, invasion, metastasis, and the response to chemotherapy. However, the isolation of exosomes and exoRNA with high quality and purity remains challenging due to the relatively small size of exosomes and the limited amount of RNA in exosomes. In this work, we developed a novel tandem enrichment method to isolate exoRNA from serum based on the specific interaction between titanium dioxide (TiO₂) and the phosphate groups on the lipid bilayer of exosomes and of the exoRNA. TiO₂-based RNA isolation was first demonstrated and optimized in HeLa cells. A total of 130.9 ± 8.34 µg of RNA was rapidly enriched from approximately 5 × 10⁶ HeLa cells within 10 min. This was a 41.5% higher yield than that using a commercial Ultrapure RNA Kit. TiO₂-based tandem enrichment of exoRNA was then performed using human serum, obtaining 64.53±3.41 ng of exoRNA from 500 µL of human serum within 30 min. A total of 2,137,902 reads, including seven types of exoRNAs, were identified from the exosomes. This method is compatible with various downstream RNA processing techniques and does not use toxic or irritating reagents, such as phenol or chloroform, providing a simple, economical, rapid, and safe approach for exoRNA extraction from biological samples.

A colorimetric and photothermal dual-mode biosensing platform based on nanozyme-functionalized flower-like DNA structures for tumor-derived exosome detection

Tumor-derived exosomes can be served as a kind of promising biomarkers for early diagnosis of cancers. Herein, a colorimetric/photothermal dual-mode exosomes sensing platform is developed for human breast cancer cell (MCF-7)-derived exosomes based on encapsulation of 3,3',5,5'-tetramethylbenzidine-loaded graphene quantum dot nanozymes (TMB-GQDzymes) into DNA flowers (DFs) via rolling circle amplification (RCA). To achieve specific detection, EpCAM aptamer for MCF-7 cell-derived exosomes is immobilized on the well plate, while the complementary sequence of another CD63 aptamer is designed into the circular template to obtain abundant capture probes. Benefitting from the dual-aptamer recognition strategy, a sandwich structure of EpCAM aptamer/exosomes/TMB-GQDzymes@DFs is formed, in which the GQDzymes can catalyze the oxidation of TMB in the presence of H₂O₂. The resulting products of TMB oxidation (oxTMB) can induce not only the absorption changes but also a near-infrared (NIR) laser-driven photothermal effect, achieving dual-mode detection of exosomes with the limit of detection (LOD) of 1027 particles/μL (colorimetry) and 2170 particles/μL (photothermal detection), respectively. In addition, this sensing platform has demonstrated excellent performance to well distinguish breast cancer patients from healthy individuals in serum samples analysis. Overall, the proposed dual-readout biosensor opens promising prospects for exosome detection in biological study and clinical applications.

Progress in research of exosomal circRNAs in colorectal cancer

Exosomes are lipid bilayer vesicles secreted by almost various cell types, including circRNAs, microRNAs (miRNAs), proteins, and nucleic acids. CircRNAs act as molecular sponges of miRNAs and participate in regulating gene transcription. This paper reviews the biogenesis, function, isolation, and identification of exosomal circRNAs and their role in the early diagnosis, prognosis, therapy, and drug resistance of colorectal cancer.

MiR-22-3p in exosomes increases the risk of heart failure after down-regulation of FURIN

Heart failure (HF) is often the inevitable manifestation of myocardial ischemia. Hypoxia can induce cardiomyocytes to express many microRNAs (miRNAs), which are highly expressed in exosomes. In addition, miR-22-3p is a marker in heart failure. Therefore, miR-22-3p was taken as the research object to explore its role and mechanism in HF. HF differentially expressed miRNAs were screened by bioinformatic analysis. The HF rats model was constructed and identified by detecting serum brain natriuretic peptide (BNP) and ultrasound analysis [left ventricular ejection fraction (LVEF) and left ventricular fractional shortening (LVFS)]. The extracted exosomes were identified by transmission electron microscopy, and Western blot was used to detect the expressions of Tsg101 and CD63. Quantitative real-time polymerase chain reaction detected miR-22-3p expression in serum, exosomes, and serum without exosomes, while the cardiomyocytes cytotoxicity was detected by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) and PKH26 staining. After overexpressing/silencing miR-22-3p in cells, cell viability, apoptosis, and apoptosis-associated markers were detected. Bioinformatic analysis screened the target gene of miR-22-3p, which was verified by dual-luciferase assay. Regulation of miR-22-3p on FURIN was measured by rescue tests. In vivo experiments were verified the above results. MiR-22-3p was identified as the research object. BNP was increased in the model group, while LVEF and LVFS were decreased. MiR-22-3p was overexpressed in HF-treated serum and exosomes. Normal exosomes did not affect cardiomyocyte function, while high concentrations of HF-treated exosomes were cytotoxic. By regulating apoptosis-related genes, overexpressed miR-22-3p inhibited cell activity and promoted cell apoptosis. Silenced miR-22-3p with opposite effects counteracted effects of HF-treated exosomes. FURIN, target gene of miR-22-3p, was negatively regulated by miR-22-3p, while overexpressed FURIN promoted cell activity and inhibited apoptosis. In vivo research was consistent with the results of cell experiments. By regulating FURIN, miR-22-3p in exosomes increases the risk of HF damage.

Comparative analysis of magnetically activated cell sorting and ultracentrifugation methods for exosome isolation

Mesenchymal stem cell-derived exosomes regulate cell migration, proliferation, differentiation, and synthesis of the extracellular matrix, giving great potential for the treatment of different diseases. The ultracentrifugation method is the gold standard method for exosome isolation due to the simple protocol, and high yield, but presents low purity and requires specialized equipment. Amelioration of technical optimization is required for quick and reliable confinement of exosomes to translate them to the clinic as cell therapeutics In this study, we hypothesized that magnetically activated cell sorting may provide, an effective, reliable, and rapid tool for exosome isolation when compared to ultracentrifugation. We, therefore, aimed to compare the efficiency of magnetically activated cell sorting and ultracentrifugation for human mesenchymal stem cell-derived exosome isolation from culture media by protein quantification, surface biomarker, size, number, and morphological analysis. Magnetically activated cell sorting provided a higher purity and amount of exosomes that carry visible magnetic beads when compared to ultracentrifugation. The particle number of the magnetically activated cell sorting group was higher than the ultracentrifugation. In conclusion, magnetically activated cell sorting presents a quick, and reliable method to collect and present human mesenchymal stem cell exosomes to clinics at high purity for potential cellular therapeutic approaches. The novel isolation and purification method may be extended to different clinical protocols using different autogenic or allogeneic cell sources.

Small Extracellular Vesicles Derived from Induced Pluripotent Stem Cells in the Treatment of Myocardial Injury

Induced pluripotent stem cell (iPSC) therapy brings great hope to the treatment of myocardial injuries, while extracellular vesicles may be one of the main mechanisms of its action. iPSC-derived small extracellular vesicles (iPSCs-sEVs) can carry genetic and proteinaceous substances and mediate the interaction between iPSCs and target cells. In recent years, more and more studies have focused on the therapeutic effect of iPSCs-sEVs in myocardial injury. IPSCs-sEVs may be a new cell-free-based treatment for myocardial injury, including myocardial infarction, myocardial ischemia-reperfusion injury, coronary heart disease, and heart failure. In the current research on myocardial injury, the extraction of sEVs from mesenchymal stem cells induced by iPSCs was widely used. Isolation methods of iPSCs-sEVs for the treatment of myocardial injury include ultracentrifugation, isodensity gradient centrifugation, and size exclusion chromatography. Tail vein injection and intraductal administration are the most widely used routes of iPSCs-sEV administration. The characteristics of sEVs derived from iPSCs which were induced from different species and organs, including fibroblasts and bone marrow, were further compared. In addition, the beneficial genes of iPSC can be regulated through CRISPR/Cas9 to change the composition of sEVs and improve the abundance and expression diversity of them. This review focused on the strategies and mechanisms of iPSCs-sEVs in the treatment of myocardial injury, which provides a reference for future research and the application of iPSCs-sEVs.

Sensitive electrochemical detection of A549 exosomes based on DNA/ferrocene-modified single-walled carbon nanotube complex

Exosome is an emerging tumor marker, whose concentration level can reflect the occurrence and development of tumors. The development of rapid and sensitive exosome detection platform is of great significance for early warning of cancer occurrence. Here, a strategy for electrochemical detection of A549-cell-derived exosomes was established based on DNA/ferrocene-modified single-walled carbon nanotube complex (DNA/SWCNT-Fc). DNA/SWCNT-Fc complexes function as a signal amplification platform to promote electron transfer between electrochemical signal molecules and electrodes, thereby improving sensitivity. At the same time, the exosomes can be attached to DNA/SWCNT-Fc nanocomposites via the established PO₄^3--Ti⁴⁺-PO₄^3- method. Moreover, the application of EGFR antibody, which can specifically capture A549 exosomes, could improve the accuracy of this sensing system. Under optimal experimental conditions, the biosensor showed good linear relationship between the peak current and the logarithm of exosomes concentration from 4.66 × 10⁶ to 9.32 × 10⁹ exosomes/mL with a detection limit of 9.38 × 10⁴ exosomes/mL. Furthermore, this strategy provides high selectivity for exosomes of different cancer cells, which can be applied to the detection of exosomes in serum samples. Thus, owing to its advantages of high sensitivity and good selectivity, this method provides a diversified platform for exosomes identification and has great potential in early diagnosis and biomedical applications.

Extracellular Vesicles Derived From 3D Cultured Antler Stem Cells Serve as a New Drug Vehicle in Osteosarcoma Treatment

Extracellular vesicles (EVs) from antler reserve mesenchymal (RM) cells play an important role in the paracrine regulation during rapid growth of antler without forming a tumor; therefore, RM-EVs become novel materials for anti-tumor studies, such as osteosarcoma treatment. However, the problem of low production of RM-EVs in traditional 2D culture limits its mechanism research and application. In this study, we established an optimal 3D culture system for antler RM cells to produce EVs (3D-RM-EVs). Morphology and property of harvested 3D-RM-EVs were normal compared with EVs from conventional 2D culture, and the miRNA profile in them was basically the same through transcriptome sequencing analysis. Based on the same number of RM cells, the volume of the culture medium collected by 3D cultural system concentrated nearly 30 times, making it more convenient for subsequent purification. In addition, EVs were harvested 30 times in 3D cultural system, greatly increasing the total amount of EVs (harvested a total of 2-3 times in 2D culture). Although 3D-RM-EVs had a limited inhibitory effect on the proliferation of K7M2 cells, the inhibition effect of 3D-RM-EVs loaded drugs (Ifosfamide + Etoposide) were more significant than that of positive drug group alone (P < 0.05). Furthermore, in vivo studies showed that 3D-RM-EVs loaded drugs (Ifosfamide + Etoposide) had the most significant tumor inhibition effect, with decreased tumor size, and could slow down body weight loss compared with Ifosfamide + Etoposide (IFO + ET) group. These results demonstrated that 3D-RM-EVs were efficiently prepared from antler RM cells and were effective as drug vehicles for the treatment of osteosarcoma.

Exosomes in pathogenesis, diagnosis, and therapy of ischemic stroke

Ischemic stroke is one of the major contributors to death and disability worldwide. Thus, there is an urgent need to develop early brain tissue perfusion therapies following acute stroke and to enhance functional recovery in stroke survivors. The morbidity, therapy, and recovery processes are highly orchestrated interactions involving the brain with other tissues. Exosomes are natural and ideal mediators of intercellular information transfer and recognized as biomarkers for disease diagnosis and prognosis. Changes in exosome contents express throughout the physiological process. Accumulating evidence demonstrates the use of exosomes in exploring unknown cellular and molecular mechanisms of intercellular communication and organ homeostasis and indicates their potential role in ischemic stroke. Inspired by the unique properties of exosomes, this review focuses on the communication, diagnosis, and therapeutic role of various derived exosomes, and their development and challenges for the treatment of cerebral ischemic stroke.

Advances in Purification, Modification, and Application of Extracellular Vesicles for Novel Clinical Treatments

Extracellular vesicles (EV) are membrane vesicles surrounded by a lipid bilayer membrane and include microvesicles, apoptotic bodies, exosomes, and exomeres. Exosome-encapsulated microRNAs (miRNAs) released from cancer cells are involved in the proliferation and metastasis of tumor cells via angiogenesis. On the other hand, mesenchymal stem cell (MSC) therapy, which is being employed in regenerative medicine owing to the ability of MSCs to differentiate into various cells, is due to humoral factors, including messenger RNA (mRNA), miRNAs, proteins, and lipids, which are encapsulated in exosomes derived from transplanted cells. New treatments that advocate cell-free therapy using MSC-derived exosomes will significantly improve clinical practice. Therefore, using highly purified exosomes that perform their original functions is desirable. In this review, we summarized advances in the purification, modification, and application of EVs as novel strategies to treat some diseases.