Therapeutic applications of extracellular vesicles: clinical promise and open questions

Neural stem cell-derived exosomes and regeneration: cell-free therapeutic strategies for traumatic brain injury

Regenerative repair of the brain after traumatic brain injury (TBI) remains an extensive clinical challenge, inspiring intensified interest in therapeutic approaches to explore superior repair strategies. Exosome therapy is another research hotspot following stem cell alternative therapy. Prior research verified that exosomes produced by neural stem cells can participate in the physiological and pathological changes associated with TBI and have potential neuroregulatory and repair functions. In comparison with their parental stem cells, exosomes have superior stability and immune tolerance and lower tumorigenic risk. In addition, they can readily penetrate the blood‒brain barrier, which makes their treatment efficiency superior to that of transplanted stem cells. Exosomes secreted by neural stem cells present a promising strategy for the development of novel regenerative therapies. Their tissue regeneration and immunomodulatory potential have made them encouraging candidates for TBI repair. The present review addresses the challenges, applications and potential mechanisms of neural stem cell exosomes in regenerating damaged brains.

Extracellular vesicles arising from apoptosis: forms, functions, and applications

Extracellular vesicles (EVs) are lipid bilayer-enclosed subcellular bodies produced by most, if not all cells. Research over the last two decades has recognised the importance of EVs in intercellular communication and horizontal transfer of biological material. EVs range in diameter from tens of nanometres up to several micrometres and are able to transfer a spectrum of biologically active cargoes - from whole organelles, through macromolecules including nucleic acids and proteins, to metabolites and small molecules - from their cells of origin to recipient cells, which may consequently become physiologically or pathologically altered. Based on their modes of biogenesis, the most renowned EV classes are (1) microvesicles, (2) exosomes (both produced by healthy cells), and (3) EVs from cells undergoing regulated death by apoptosis (ApoEVs). Microvesicles bud directly from the plasma membrane, while exosomes are derived from endosomal compartments. Current knowledge of the formation and functional properties of ApoEVs lags behind that of microvesicles and exosomes, but burgeoning evidence indicates that ApoEVs carry manifold cargoes, including mitochondria, ribosomes, DNA, RNAs, and proteins, and perform diverse functions in health and disease. Here we review this evidence, which demonstrates substantial diversity in the luminal and surface membrane cargoes of ApoEVs, permitted by their very broad size range (from around 50 nm to >5 μm; the larger often termed apoptotic bodies), strongly suggests their origins through both microvesicle- and exosome-like biogenesis pathways, and indicates routes through which they interact with recipient cells. We discuss the capacity of ApoEVs to recycle cargoes and modulate inflammatory, immunological, and cell fate programmes in normal physiology and in pathological scenarios such as cancer and atherosclerosis. Finally, we provide a perspective on clinical applications of ApoEVs in diagnostics and therapeutics. © 2023 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

Antitumor mechanism of cannabidiol hidden behind cancer hallmarks

Cannabinoids have been utilized for recreational and therapeutic purposes for over 4,000 years. As the primary ingredient in exogenous cannabinoids, Cannabidiol (CBD) has drawn a lot of interest from researchers due to its negligible psychotropic side effects and potential tumor-suppressing properties. However, the obscure mechanisms that underlie them remain a mystery. Complex biological mechanisms are involved in the progression of cancer, and malignancies have a variety of acquired biological capabilities, including sustained proliferation, death evasion, neovascularization, tissue invasion and metastasis, immune escape, metabolic reprogramming, induction of tumor-associated inflammation, cancerous stemness and genomic instability. Nowadays, the role of CBD hidden in these hallmarks is gradually revealed. Nevertheless, flaws or inconsistencies in the recent studies addressing the anti-cancer effects of CBD still exist. The purpose of this review is to evaluate the potential mechanisms underlying the role of CBD in a range of tumor-acquired biological capabilities. We propose potential drugs that may have a synergistic effect with CBD and provide optional directions for future research.

A tale of exosomes and their implication in cancer

Cancer is a cause of high deaths worldwide and also a huge burden for the health system. Cancer cells have unique properties such as a high rate of proliferation, self-renewal, metastasis, and treatment resistance, therefore, the development of novel diagnoses of cancers is a tedious task. Exosomes are secreted by virtually all cell types and have the ability to carry a multitude of biomolecules crucial for intercellular communication, hence, contributing a crucial part in the onset and spread of cancer. These exosomal components can be utilized in the development of markers for diagnostic and prognostic purposes for various cancers. This review emphasized primarily the following topics: exosomes structure and functions, isolation and characterization strategies of exosomes, the role of exosomal contents in cancer with a focus in particular on noncoding RNA and protein, exosomes, and the cancer microenvironment interactions, cancer stem cells, and tumor diagnosis and prognosis based on exosomes.

A Tale of Two: When Neural Stem Cells Encounter Hypoxia

Normoxia is defined as an oxygen concentration of 20.9%, as in room air, whereas hypoxia refers to any oxygen concentration less than this. Any physiological oxygen deficiency or tissue oxygen deficiency relative to demand is called hypoxia. Neural stem cells (NSCs) are multipotent stem cells that can differentiate into multiple cell lines such as neurons, oligodendrocytes, and astrocytes. Under hypoxic conditions, the apoptosis rate of NSCs increases remarkably in vitro or in vivo. However, some hypoxia promotes the proliferation and differentiation of NSCs. The difference is related to the oxygen concentration, the duration of hypoxia, the hypoxia tolerance threshold of the NSCs, and the tissue source of the NSCs. The main mechanism of hypoxia-induced proliferation and differentiation involves an increase in cyclin and erythropoietin concentrations, and hypoxia-inducible factors play a key role. Multiple molecular pathways are activated during hypoxia, including Notch, Wnt/β-catenin, PI3K/Akt, and altered microRNA expression. In addition, we review the protective effect of exogenous NSCs transplantation on ischemic or anoxic organs, the therapeutic potential of hypoxic preconditioning on exogenous NSCs and clinical application of NSCs.

Advances in Therapeutic Applications of Extracellular Vesicles

Extracellular vesicles (EVs) are nanoscale bilayer phospholipid membrane vesicles released by cells. Contained large molecules such as nucleic acid, protein, and lipid, EVs are an integral part of cell communication. The contents of EVs vary based on the cell source and play an important role in both pathological and physiological conditions. EVs can be used as drugs or targets in disease treatment, and changes in the contents of EVs can indicate the progression of diseases. In recent years, with the continuous exploration of the structure, characteristics, and functions of EVs, the potential of engineered EVs for drug delivery and therapy being constantly explored. This review provides a brief overview of the structure, characteristics and functions of EVs, summarizes the advanced application of EVs and outlook on the prospect of it. It is our hope that this review will increase understanding of the current development of medical applications of EVs and help us overcome future challenges.

Biogenesis, Composition and Potential Therapeutic Applications of Mesenchymal Stem Cells Derived Exosomes in Various Diseases

Exosomes are nanovesicles with a wide range of chemical compositions used in many different applications. Mesenchymal stem cell-derived exosomes (MSCs-EXOs) are spherical vesicles that have been shown to mediate tissue regeneration in a variety of diseases, including neurological, autoimmune and inflammatory, cancer, ischemic heart disease, lung injury, and liver fibrosis. They can modulate the immune response by interacting with immune effector cells due to the presence of anti-inflammatory compounds and are involved in intercellular communication through various types of cargo. MSCs-EXOs exhibit cytokine storm-mitigating properties in response to COVID-19. This review discussed the potential function of MSCs-EXOs in a variety of diseases including neurological, notably epileptic encephalopathy and Parkinson's disease, cancer, angiogenesis, autoimmune and inflammatory diseases. We provided an overview of exosome biogenesis and factors that regulate exosome biogenesis. Additionally, we highlight the functions and potential use of MSCs-EXOs in the treatment of the inflammatory disease COVID-19. Finally, we covered a strategies and challenges of MSCs-EXOs. Finally, we discuss conclusion and future perspectives of MSCs-EXOs.

Plasma exosome proteomics reveals the pathogenesis mechanism of post-stroke cognitive impairment

Exploration and utilization of exosome biomarkers and their related functions provide the possibility for the diagnosis and treatment of post-stroke cognitive impairment (PSCI). To identify the new diagnostic and prognostic biomarkers of plasma exosome were uzed label-free quantitative proteomics and biological information analysis in PSCI patients. Behavioral assessments were performed, including the Mini-Mental Status Examination (MMSE), the Montreal Cognitive Assessment (MoCA), the Barthel index, the Morse Fall Seale (MFS) between control group (n = 10) and PSCI group (n = 10). The blood samples were collected to analyse the biomarker and differentially expressed proteins of plasma exosome using label-free quantitative proteomics and biological information. The exosomes marker proteins were determined by Western blot. The exosome morphology was observed by transmission electron microscopy. The scores of MMSE and MoCA were significantly decreased in the PSCI group. The PT% and high-density lipoprotein decreased and the INR ratio increased in PSCI group. The mean size of exosome was approximately 71.6 nm and the concentration was approximately 6.8E+7 particles/mL. Exosome proteomics identified 259 differentially expressed proteins. The mechanisms of cognitive impairment are related to regulate the degradation of ubiquitinated proteins, calcium dependent protein binding, cell adhesive protein binding, formation of fibrin clot, lipid metabolism and ATP-dependent degradation of ubiquitinated proteins in plasma exosome of PSCI patients. Plasma levels of YWHAZ and BAIAP2 were significantly increased while that of IGHD, ABCB6 and HSPD1 were significantly decreased in PSCI patients. These proteins might be target-related proteins and provide global insights into pathogenesis mechanisms of PSCI at plasma exosome proteins level.

Emerging role of bacterial outer membrane vesicle in gastrointestinal tract

Bacteria form a highly complex ecosystem in the gastrointestinal (GI) tract. In recent years, mounting evidence has shown that bacteria can release nanoscale phospholipid bilayer particles that encapsulate nucleic acids, proteins, lipids, and other molecules. Extracellular vesicles (EVs) are secreted by microorganisms and can transport a variety of important factors, such as virulence factors, antibiotics, HGT, and defensive factors produced by host eukaryotic cells. In addition, these EVs are vital in facilitating communication between microbiota and the host. Therefore, bacterial EVs play a crucial role in maintaining the GI tract's health and proper functioning. In this review, we outlined the structure and composition of bacterial EVs. Additionally, we highlighted the critical role that bacterial EVs play in immune regulation and in maintaining the balance of the gut microbiota. To further elucidate progress in the field of intestinal research and to provide a reference for future EV studies, we also discussed the clinical and pharmacological potential of bacterial EVs, as well as the necessary efforts required to understand the mechanisms of interaction between bacterial EVs and gut pathogenesis.

Melatonin and TGF-β-Mediated Release of Extracellular Vesicles

The immune system, unlike other systems, must be flexible and able to "adapt" to fully cope with lurking dangers. The transition from intracorporeal balance to homeostasis disruption is associated with activation of inflammatory signaling pathways, which causes modulation of the immunology response. Chemotactic cytokines, signaling molecules, and extracellular vesicles act as critical mediators of inflammation and participate in intercellular communication, conditioning the immune system's proper response. Among the well-known cytokines allowing for the development and proper functioning of the immune system by mediating cell survival and cell-death-inducing signaling, the tumor necrosis factor α (TNF-α) and transforming growth factor β (TGF-β) are noteworthy. The high bloodstream concentration of those pleiotropic cytokines can be characterized by anti- and pro-inflammatory activity, considering the powerful anti-inflammatory and anti-oxidative stress capabilities of TGF-β known from the literature. Together with the chemokines, the immune system response is also influenced by biologically active chemicals, such as melatonin. The enhanced cellular communication shows the relationship between the TGF-β signaling pathway and the extracellular vesicles (EVs) secreted under the influence of melatonin. This review outlines the findings on melatonin activity on TGF-β-dependent inflammatory response regulation in cell-to-cell communication leading to secretion of the different EV populations.

Exosomes derived from EphB2-overexpressing bone marrow mesenchymal stem cells regulate immune balance and repair barrier function

BACKGROUND

Disruption of intestinal barrier function and an imbalance in intestinal immunity are crucial for the occurrence and development of ulcerative colitis. Because of their important roles in regulating inflammation and immunity, exosomes (Exos) released from bone marrow mesenchymal stem cells (BMSCs) may be useful for treating ulcerative colitis. The EphB/EphrinB signaling pathway plays a crucial role in the inflammatory process and the development and function of immune cells, and can mediate long-distance intercellular communication through extracellular vesicles. This study was conducted to explore the effects of pre-modified BMSC-Exos expressing EphB2 (EphB2-Exos) on immunoregulation in vitro.

METHODS

We transfected a lentivirus vector encoding EphB2 into BMSCs and isolated EphB2-Exos from the culture supernatant. Inflammation and oxidative damage in the human colon adenocarcinoma cell line (Caco-2) were induced by dextran sulfate sodium/hydrogen peroxide. In addition, spleen CD4⁺ T lymphocytes of rats were sorted in vitro. We conducted a series of experiments to explore the biological functions of EphB2-Exos.

RESULTS

EphB2-Exos were successfully isolated and were found to significantly protect the activity, proliferation, and migration of Caco-2 cells that were inhibited by dextran sulfate sodium. EphB2-Exos alleviated inflammation and apoptosis and increased the activity of antioxidant enzymes while inhibiting oxidative stress in Caco-2 cells. EphB2-Exos restored intestinal barrier function by inhibiting the RhoA/ROCK pathway and regulated the polarization of CD4⁺T cells.

CONCLUSION

EphB2-Exos enhanced intestinal barrier function and regulated the immune balance by inhibiting the RhoA/ROCK pathway in vitro. These findings suggest that EphB2-Exos can be applied as a cell-free therapy for ulcerative colitis.

Extracellular Vesicles as Delivery Shippers for Noncoding RNA-Based Modulation of Angiogenesis: Insights from Ischemic Stroke and Cancer

Ischemic stroke and systemic cancer are two of the leading causes of mortality. Hypoxia is a central pathophysiological component in ischemic stroke and cancer, representing a joint medical function. This function includes angiogenesis regulation. Vascular remodeling coupled with axonal outgrowth following cerebral ischemia is critical in improving poststroke neurological functional recovery. Antiangiogenic strategies can inhibit cancer vascularization and play a vital role in impeding cancer growth, invasion, and metastasis. Although there are significant differences in the cause of angiogenesis across both pathophysiological conditions, emerging evidence states that common signaling structures, such as extracellular vesicles (EVs) and noncoding RNAs (ncRNAs), are involved in this context. EVs, heterogeneous membrane vesicles encapsulating proteomic genetic information from parental cells, act as multifunctional regulators of intercellular communication. Among the multifaceted roles in modulating biological responses, exhaustive evidence shows that ncRNAs are selectively sorted into EVs, modulating common specific aspects of cancer development and stroke prognosis, namely, angiogenesis. This review will discuss recent advancements in the EV-facilitated/inhibited progression of specific elements of angiogenesis with a particular concern about ncRNAs within these vesicles. The review is concluded by underlining the clinical opportunities of EV-derived ncRNAs as diagnostic, prognostic, and therapeutic agents.

Choroid Plexus Modulates Subventricular Zone Adult Neurogenesis and Olfaction Through Secretion of Small Extracellular Vesicles

The choroid plexus (CP) in brain ventricles secrete cerebrospinal fluid (CSF) that bathes the adjacent subventricular zone (SVZ); the latter is the largest neurogenic region in adult brain harboring neural stem/progenitor cells (NSPCs) and supplies newborn neurons to the olfactory bulb (OB) for normal olfaction. We discovered the presence of a CP-SVZ regulatory (CSR) axis in which the CP, by secreting small extracellular vesicles (sEVs), regulated adult neurogenesis in the SVZ and maintained olfaction. The proposed CSR axis was supported by 1) differential neurogenesis outcomes in the OB when animals treated with intracerebroventricular (ICV) infusion of sEVs collected from the CP of normal or manganese (Mn)-poisoned mice, 2) progressively diminished SVZ adult neurogenesis in mice following CP-targeted knockdown of SMPD3 to suppress CP sEV secretion, and 3) compromised olfactory performance in these CP-SMPD3-knockdown mice. Collectively, our findings demonstrate the biological and physiological presence of this sEV-dependent CSR axis in adult brains.

HIGHLIGHTS

CP-secreted sEVs regulate adult neurogenesis in the SVZ.CP-secreted sEVs modulate newborn neurons in the OB.Suppression of sEV secretion from the CP deteriorates olfactory performance.

Extracellular Vesicles and MicroRNA in Myelodysplastic Syndromes

The bone marrow niche plays an increasing role in the pathophysiogenesis of myelodysplastic syndromes. More specifically, mesenchymal stromal cells, which can secrete extracellular vesicles and their miRNA contents, modulate the fate of hematopoietic stem cells leading to leukemogenesis. Extracellular vesicles can mediate their miRNA and protein contents between nearby cells but also in the plasma of the patients, being potent tools for diagnosis and prognostic markers in MDS. They can be targeted by antisense miRNA or by modulators of the secretion of extracellular vesicles and could lead to future therapeutic directions in MDS.

Expanding therapeutic strategies for intracellular bacterial infections through conjugates of apoptotic body-antimicrobial peptides

Macrophage intracellular infections are difficult to treat because conventional antibiotics tend to have poor penetration of mammalian cells. As a consequence, the immune response is affected and bacteria remain protected inside macrophages. The use of antimicrobial peptides (AMPs) is one of the alternatives developed as new treatments because of their broad spectrum of action. To improve drug delivery into the intracellular space, extracellular vesicles (EVs) have emerged as an innovative strategy for drug delivery. In particular, apoptotic bodies (ApoBDs) are EVs that exhibit attraction to macrophages, which makes them a promising means of improving AMP delivery to treat macrophage intracellular infections. Here, we review important aspects that should be taken into account when developing ApoBD-AMP conjugates.

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

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

Nucleic acid drug vectors for diagnosis and treatment of brain diseases

Nucleic acid drugs have the advantages of rich target selection, simple in design, good and enduring effect. They have been demonstrated to have irreplaceable superiority in brain disease treatment, while vectors are a decisive factor in therapeutic efficacy. Strict physiological barriers, such as degradation and clearance in circulation, blood-brain barrier, cellular uptake, endosome/lysosome barriers, release, obstruct the delivery of nucleic acid drugs to the brain by the vectors. Nucleic acid drugs against a single target are inefficient in treating brain diseases of complex pathogenesis. Differences between individual patients lead to severe uncertainties in brain disease treatment with nucleic acid drugs. In this Review, we briefly summarize the classification of nucleic acid drugs. Next, we discuss physiological barriers during drug delivery and universal coping strategies and introduce the application methods of these universal strategies to nucleic acid drug vectors. Subsequently, we explore nucleic acid drug-based multidrug regimens for the combination treatment of brain diseases and the construction of the corresponding vectors. In the following, we address the feasibility of patient stratification and personalized therapy through diagnostic information from medical imaging and the manner of introducing contrast agents into vectors. Finally, we take a perspective on the future feasibility and remaining challenges of vector-based integrated diagnosis and gene therapy for brain diseases.

Human macrophage-engineered vesicles for utilization in ovarian cancer treatment

Background

Ovarian cancer is a deadly female malignancy with a high rate of recurrent and chemotherapy-resistant disease. Tumor-associated macrophages (TAMs) are a significant component of the tumor microenvironment and include high levels of M2-protumor macrophages that promote chemoresistance and metastatic spread. M2 macrophages can be converted to M1 anti-tumor macrophages, representing a novel therapeutic approach. Vesicles engineered from M1 macrophages (MEVs) are a novel method for converting M2 macrophages to M1 phenotype-like macrophages.

Methods

Macrophages were isolated and cultured from human peripheral blood mononuclear cells. Macrophages were stimulated to M1 or M2 phenotypes utilizing LPS/IFN-γ and IL-4/IL-13, respectively. M1 MEVs were generated with nitrogen cavitation and ultracentrifugation. Co-culture of ovarian cancer cells with macrophages and M1 MEVs was followed by cytokine, PCR, and cell viability analysis. Murine macrophage cell line, RAW264.7 cells were cultured and used to generate M1 MEVs for use in ovarian cancer xenograft models.

Results

M1 MEVs can effectively convert M2 macrophages to an M1-like state both in isolation and when co-cultured with ovarian cancer cells in vitro, resulting in a reduced ovarian cancer cell viability. Additionally, RAW264.7 M1 MEVs can localize to ovarian cancer tumor xenografts in mice.

Conclusion

Human M1 MEVs can repolarize M2 macrophages to a M1 state and have anti-cancer activity against ovarian cancer cell lines. RAW264.7 M1 MEVs localize to tumor xenografts in vivo murine models.

Engineering Human Mesenchymal Bodies in a Novel 3D-Printed Microchannel Bioreactor for Extracellular Vesicle Biogenesis

Human Mesenchymal Stem Cells (hMSCs) and their derived products hold potential in tissue engineering and as therapeutics in a wide range of diseases. hMSCs possess the ability to aggregate into "spheroids", which has been used as a preconditioning technique to enhance their therapeutic potential by upregulating stemness, immunomodulatory capacity, and anti-inflammatory and pro-angiogenic secretome. Few studies have investigated the impact on hMSC aggregate properties stemming from dynamic and static aggregation techniques. hMSCs' main mechanistic mode of action occur through their secretome, including extracellular vesicles (EVs)/exosomes, which contain therapeutically relevant proteins and nucleic acids. In this study, a 3D printed microchannel bioreactor was developed to dynamically form hMSC spheroids and promote hMSC condensation. In particular, the manner in which dynamic microenvironment conditions alter hMSC properties and EV biogenesis in relation to static cultures was assessed. Dynamic aggregation was found to promote autophagy activity, alter metabolism toward glycolysis, and promote exosome/EV production. This study advances our knowledge on a commonly used preconditioning technique that could be beneficial in wound healing, tissue regeneration, and autoimmune disorders.

Plant-derived extracellular vesicles: Recent advancements and current challenges on their use for biomedical applications

Extracellular vesicles (EVs) represent a diverse class of lipid bilayer membrane vesicles released by both animal and plant cells. These ubiquitous vesicles are involved in intercellular communication and transport of various biological cargos, including proteins, lipids, and nucleic acids. In recent years, interest in plant-derived EVs has increased tremendously, as they serve as a scalable and sustainable alternative to EVs derived from mammalian sources. In vitro and in vivo findings have demonstrated that these plant-derived vesicles (PDVs) possess intrinsic therapeutic activities that can potentially treat diseases and improve human health. In addition, PDVs can also act as efficient and biocompatible drug carriers. While preclinical studies have shown promising results, there are still several challenges and knowledge gaps that have to be addressed for the successful translation of PDVs into clinical applications, especially in view of the lack of standardised protocols for material handling and PDV isolation from various plant sources. This review provides the readers with a quick overview of the current understanding and research on PDVs, critically analysing the current challenges and highlighting the immense potential of PDVs as a novel class of therapeutics to treat human diseases. It is expected that this work will guide scientists to address the knowledge gaps currently associated with PDVs and promote new advances in plant-based therapeutic solutions.

Exosome RNA Sequencing as a Tool in the Search for Cancer Biomarkers

Numerous noninvasive methods are currently being used to determine biomarkers for diseases such as cancer. However, these methods are not always precise and reliable. Thus, there is an unmet need for better diagnostic and prognostic biomarkers that will be used to diagnose cancer in early, more treatable stages of the disease. Exosomes are extracellular vesicles of endocytic origin released by the majority of cells. Exosomes contain and transport nucleic acids, proteins, growth factors, and cytokines from their parent cells to surrounding or even distant cells via circulation in biofluids. Exosomes have attracted the interest of researchers, as recent data indicate that exosome content may be indicative of disease stages and may contribute to disease progression via exosome-mediated extracellular communication. Therefore, the contents of these vesicles are being investigated as possible biomarkers for disease diagnosis and prognosis. The functions of exosomes and their contents in disease development are becoming clearer as isolation and analytical methods, such as RNA sequencing, advance. In this review, we discuss current advances and challenges in exosomal content analyses with emphasis on information that can be generated using RNA sequencing. We also discuss how the RNA sequencing of exosomes may be used to discover novel biomarkers for the detection of different stages for various cancers using specific microRNAs that were found to be differentially expressed between healthy controls and cancer-diagnosed subjects.

Artificial Cells: Past, Present and Future

Artificial cells are constructed to imitate natural cells and allow researchers to explore biological process and the origin of life. The construction methods for artificial cells, through both top-down or bottom-up approaches, have achieved great progress over the past decades. Here we present a comprehensive overview on the development of artificial cells and their properties and applications. Artificial cells are derived from lipids, polymers, lipid/polymer hybrids, natural cell membranes, colloidosome, metal-organic frameworks and coacervates. They can be endowed with various functions through the incorporation of proteins and genes on the cell surface or encapsulated inside of the cells. These modulations determine the properties of artificial cells, including producing energy, cell growth, morphology change, division, transmembrane transport, environmental response, motility and chemotaxis. Multiple applications of these artificial cells are discussed here with a focus on therapeutic applications. Artificial cells are used as carriers for materials and information exchange and have been shown to function as targeted delivery systems of personalized drugs. Additionally, artificial cells can function to substitute for cells with impaired function. Enzyme therapy and immunotherapy using artificial cells have been an intense focus of research. Finally, prospects of future development of cell-mimic properties and broader applications are highlighted.

Advances of engineered extracellular vesicles-based therapeutics strategy

Extracellular vesicles (EVs) are a heterogeneous population of lipid bilayer membrane-bound vesicles which encapsulate bioactive molecules, such as nucleic acids, proteins, and lipids. They mediate intercellular communication through transporting internally packaged molecules, making them attractive therapeutics carriers. Over the last decades, a significant amount of research has implied the potential of EVs servings as drug delivery vehicles for nuclear acids, proteins, and small molecular drugs. However, several challenges remain unresolved before the clinical application of EV-based therapeutics, including lack of specificity, stability, biodistribution, storage, large-scale manufacturing, and the comprehensive analysis of EV composition. Technical development is essential to overcome these issues and enhance the pre-clinical therapeutic effects. In this review, we summarize the current advancements in EV engineering which demonstrate their therapeutic potential.

Update on the application of mesenchymal stem cell-derived exosomes in the treatment of Parkinson's disease: A systematic review

Parkinson's disease (PD) has become the second largest neurodegenerative disease after Alzheimer's disease, and its incidence is increasing year by year. Traditional dopamine replacement therapy and deep brain stimulation can only alleviate the clinical symptoms of patients with PD but cannot cure the disease. In recent years, stem cell therapy has been used to treat neurodegenerative diseases. Many studies have shown that stem cell transplantation has a therapeutic effect on PD. Here, we review recent studies indicating that exosomes derived from mesenchymal stem cells also have the potential to treat PD in animal models, but the exact mechanism remains unclear. This article reviews the mechanisms through which exosomes are involved in intercellular information exchange, promote neuroprotection and freely cross the blood-brain barrier in the treatment of PD. The increase in the incidence of PD and the decline in the quality of life of patients with advanced PD have placed a heavy burden on patients, families and society. Therefore, innovative therapies for PD are urgently needed. Herein, we discuss the mechanisms underlying the effects of exosomes in PD, to provide new insights into the treatment of PD. The main purpose of this article is to explore the therapeutic potential of exosomes derived from mesenchymal stem cells and future research directions for this degenerative disease.

How Does Lifestyle Affect Hematopoiesis and the Bone Marrow Microenvironment?

Lifestyle factors are modifiable behavioral factors that have a significant impact on health and longevity. Diet-induced obesity and physical activity/exercise are two prevalent lifestyle factors that have strong relationships to overall health. The mechanisms linking obesity to negative health outcomes and the mechanisms linking increased participation in physical activity/exercise to positive health outcomes are beginning to be elucidated. Chronic inflammation, due in part to overproduction of myeloid cells from hematopoietic stem cells (HSCs) in the bone marrow, is an established mechanism responsible for the negative health effects of obesity. Recent work has shown that exercise training can reverse the aberrant myelopoiesis present in obesity in part by restoring the bone marrow microenvironment. Specifically, exercise training reduces marrow adipose tissue, increases HSC retention factor expression, and reduces pro-inflammatory cytokine levels in the bone marrow. Other, novel mechanistic factors responsible for these exercise-induced effects, including intercellular communication using extracellular vesicles (EVs), is beginning to be explored. This review will summarize the recent literature describing the effects of exercise on hematopoiesis in individuals with obesity and introduce the potential contribution of EVs to this process.

Extracellular Vesicles: The Next Generation Theranostic Nanomedicine for Inflammatory Bowel Disease

The recent rapid development in the field of extracellular vesicles (EVs) based nanotechnology has provided unprecedented opportunities for nanomedicine platforms. As natural nanocarriers, EVs such as exosomes, exosome-like nanoparticles and outer membrane vesicles (OMVs), have unique structure/composition/morphology characteristics, and show excellent physical and chemical/biochemical properties, making them a new generation of theranostic nanomedicine. Here, we reviewed the characteristics of EVs from the perspective of their formation and biological function in inflammatory bowel disease (IBD). Moreover, EVs can crucially participate in the interaction and communication of intestinal epithelial cells (IECs)-immune cells-gut microbiota to regulate immune response, intestinal inflammation and intestinal homeostasis. Interestingly, based on current representative examples in the field of exosomes and exosome-like nanoparticles for IBD treatment, it is shown that plant, milk, and cells-derived exosomes and exosome-like nanoparticles can exert a therapeutic effect through their components, such as proteins, nucleic acid, and lipids. Moreover, several drug loading methods and target modification of exosomes are used to improve their therapeutic capability. We also discussed the application of exosomes and exosome-like nanoparticles in the treatment of IBD. In this review, we aim to better and more clearly clarify the underlying mechanisms of the EVs in the pathogenesis of IBD, and provide directions of exosomes and exosome-like nanoparticles mediated for IBD treatment.

Functional Intercellular Transmission of miHTT via Extracellular Vesicles: An In Vitro Proof-of-Mechanism Study

Huntington's disease (HD) is a fatal neurodegenerative disorder caused by GAG expansion in exon 1 of the huntingtin (HTT) gene. AAV5-miHTT is an adeno-associated virus serotype 5-based vector expressing an engineered HTT-targeting microRNA (miHTT). Preclinical studies demonstrate the brain-wide spread of AAV5-miHTT following a single intrastriatal injection, which is partly mediated by neuronal transport. miHTT has been previously associated with extracellular vesicles (EVs), but whether EVs mediate the intercellular transmission of miHTT remains unknown. A contactless culture system was used to evaluate the transport of miHTT, either from a donor cell line overexpressing miHTT or AAV5-miHTT transduced neurons. Transfer of miHTT to recipient (HEK-293T, HeLa, and HD patient-derived neurons) cells was observed, which significantly reduced HTT mRNA levels. miHTT was present in EV-enriched fractions isolated from culture media. Immunocytochemical and in situ hybridization experiments showed that the signal for miHTT and EV markers co-localized, confirming the transport of miHTT within EVs. In summary, we provide evidence that an engineered miRNA-miHTT-is loaded into EVs, transported across extracellular space, and taken up by neighboring cells, and importantly, that miHTT is active in recipient cells downregulating HTT expression. This represents an additional mechanism contributing to the widespread biodistribution of AAV5-miHTT.

Comparison of characteristics and tumor targeting properties of extracellular vesicles derived from primary NK cells or NK-cell lines stimulated with IL-15 or IL-12/15/18

NK cell-based therapies have shown promise for hematological cancer forms, but their use against solid tumors is hampered by their poor ability to infiltrate the tumor. NK cells release extracellular vesicles (EVs) containing cytolytic proteins, indicating that NK-cell derived EVs may have therapeutic potential. In this study, we compared the tumor-targeting potential of EVs derived from either primary NK cells or the NK cell lines NK-92 and KHYG-1 cultured in IL-15 alone or in combination with IL-12 and IL-18. Primary NK cells were also stimulated through the activating receptor CD16. Tumor cell apoptosis was measured using a panel of human colon, melanoma, glioblastoma, prostate, breast, and ovarian tumor cell line spheroids. NK cells or NK-92 cells stimulated with IL-12, IL-15, and IL-18 generated EVs with higher efficiency than EVs from resting cells, although similar amounts of EVs were produced under both conditions. Proteomic analysis indicated similar distribution of cytolytic proteins in EVs from primary NK cells and NK-92, but lower levels in KHYG-1 EVs that translated into poor capacity for KHYG-1 EVs at targeting tumor cell lines. Further, we show that CD16-stimulated NK cells release low amounts of EVs devoid of cytolytic proteins. Importantly, EVs from cytokine-stimulated NK cells penetrate into the spheroid core, and tumor spheroid susceptibility to NK-cell derived EVs was linked to differential expression of the NKG2D ligands MICA/B, which was blocked with an anti-NKG2D antibody. We conclude that EVs from activated primary NK cells or NK-92 cells has the best potential to infiltrate and target solid tumors.

Mesenchymal Stem Cell-Derived Extracellular Vesicles as Idiopathic Pulmonary Fibrosis Microenvironment Targeted Delivery

Idiopathic pulmonary fibrosis (IPF) affects an increasing number of people globally, yet treatment options remain limited. At present, conventional treatments depending on drug therapy do not show an ideal effect in reversing the lung damage or extending the lives of IPF patients. In recent years, more and more attention has focused on extracellular vesicles (EVs) which show extraordinary therapeutic effects in inflammation, fibrosis disease, and tissue damage repair in many kinds of disease therapy. More importantly, EVs can be modified or used as a drug or cytokine delivery tool, targeting injury sites to enhance treatment efficiency. In light of this, the treatment strategy of mesenchymal stem cell-extracellular vesicles (MSC-EVs) targeting the pulmonary microenvironment for IPF provides a new idea for the treatment of IPF. In this review, we summarized the inflammation, immune dysregulation, and extracellular matrix microenvironment (ECM) disorders in the IPF microenvironment in order to reveal the treatment strategy of MSC-EVs targeting the pulmonary microenvironment for IPF.

The potential use of mesenchymal stem cells and their exosomes in Parkinson's disease treatment

Parkinson's disease (PD) is the second most predominant neurodegenerative disease worldwide. It is recognized clinically by severe complications in motor function caused by progressive degeneration of dopaminergic neurons (DAn) and dopamine depletion. As the current standard of treatment is focused on alleviating symptoms through Levodopa, developing neuroprotective techniques is critical for adopting a more pathology-oriented therapeutic approach. Regenerative cell therapy has provided us with an unrivalled platform for evaluating potentially effective novel methods for treating neurodegenerative illnesses over the last two decades. Mesenchymal stem cells (MSCs) are most promising, as they can differentiate into dopaminergic neurons and produce neurotrophic substances. The precise process by which stem cells repair neuronal injury is unknown, and MSC-derived exosomes are suggested to be responsible for a significant portion of such effects. The present review discusses the application of mesenchymal stem cells and MSC-derived exosomes in PD treatment.

Stem cells for treatment of liver fibrosis/cirrhosis: clinical progress and therapeutic potential

Cost-effective treatment strategies for liver fibrosis or cirrhosis are limited. Many clinical trials of stem cells for liver disease shown that stem cells might be a potential therapeutic approach. This review will summarize the published clinical trials of stem cells for the treatment of liver fibrosis/cirrhosis and provide the latest overview of various cell sources, cell doses, and delivery methods. We also describe the limitations and strengths of various stem cells in clinical applications. Furthermore, to clarify how stem cells play a therapeutic role in liver fibrosis, we discuss the molecular mechanisms of stem cells for treatment of liver fibrosis, including liver regeneration, immunoregulation, resistance to injury, myofibroblast repression, and extracellular matrix degradation. We provide a perspective for the prospects of future clinical implementation of stem cells.

Therapeutic efficacy of extracellular vesicles to suppress allograft rejection in preclinical kidney transplantation models: A systematic review and meta-analysis

BACKGROUND

Kidney transplantation is the optimal treatment of end-stage renal disease. Extracellular vesicles (EVs) have tremendous therapeutic potential, but their role in modulating immune responses in kidney transplantation remains unclear.

METHODS

We performed a systematic review and meta-analysis to investigate the therapeutic efficacy of EVs in preclinical kidney transplant models. Outcomes for meta-analysis were graft survival and renal function. Subgroup analysis was conducted between immune cell derived EVs (immune cell-EVs) and mesenchymal stromal cell derived EVs (MSC-EVs).

RESULTS

Seven studies published from 2013 to 2021 were included. The overall effects showed that EVs had a positive role in prolonging allograft survival (standardized mean difference (SMD) = 2.00; 95% confidence interval (CI), 0.79 to 3.21; P < 0.01; I² = 94%), reducing serum creatinine (SCr) (SMD = -2.19; 95%CI, -3.35 to -1.04; P < 0.01; I² = 93%) and blood urea nitrogen (BUN) concentrations (SMD = -1.69; 95%CI, -2.98 to -0.40; P = 0.01; I² = 94%). Subgroup analyses indicated that only immune cell-EVs significantly prolonged graft survival and improve renal function but not MSC-EVs.

CONCLUSIONS

EVs are promising candidates to suppress allograft rejection and improve kidney transplant outcome. Immune cell-EVs showed their superiority over MSC-EVs in prolonging graft survival and improving renal function. For interpretation of the outcomes, additional studies are needed to validate these findings.

Mesenchymal stem cells derived extracellular vesicles: A promising nanomedicine for drug delivery system

An ideal drug delivery system should selectively deliver incorporated therapeutics to the target site, escape from immune cells recognition and degradation, and act controlled release of incorporated therapeutics in the site targeted. Extracellular vesicles (EVs) have gained great attention for their potential application as a drug delivery system in nanomedicine. EVs such as exosomes are membrane-bound vesicles that contribute to intracellular communication by transferring various biomolecules including RNAs, proteins, and lipids. EVs derived from mesenchymal stem cells (MSCs-EVs) have several advantages such as low immunogenicity, high biocompatibility, and stability against conventional synthetic carriers, opening new avenues for delivering theaputic agents to target cells. To obtain modified MSCs-EVs, several loading methods are used to incorporate different therapeutic agents including proteins, RNAs, and chemotherapeutic drugs into MSCs-EVs. In addition, modification of MSCs-EVs surface may improve their potential in targeted therapies. Modified MSCs-EVs have been shown to improve many diseases including, cancer, cardiovascular diseases, and diabetes mellitus. While land greatly potential, the application of MSCs-EVs as a drug-delivery system has been hampered by several challenges. Clinical translation of modified-EVs needs further scrutiny. In this review, we discuss the biogenesis and production of EVs along with the loading and modification methods of MSCs-EVs. We also describe numerous MSCs-EVs based delivery studies with a focus on advantages and challenges when using them as a drug delivery system.

New insights of engineering plant exosome-like nanovesicles as a nanoplatform for therapeutics and drug delivery

Plant exosome-like nanovesicles (PELNVs) are membrane-encapsulated nanostructures released from cells into their surroundings. PELNVs have an important role in intercellular and interspecies communication in all three domains of life. They act as protective compartments for the long-distance transit of signal molecules like proteins, nucleic acids, lipids, and other metabolites. A range of plants and vegetables can emit PELNVs. The importance of PELNVs in interspecies communication stems from their concentration in biomolecules (lipids, proteins, and miRNAs), lack of toxicity, ease of internalization by cells, and anti-inflammatory, immune-modulatory, and regenerative characteristics. PELNVs derived from numerous fruits and vegetables are biocompatible, biodegradable, and abundant in various plant species. Moreover, their convincing physicochemical characteristics underpin their modulative role in physiological and pathological processes, all of which have fueled speculation that these nanovesicles could be particularly adept at developing future-generation bio-therapeutic platforms. The goal of this review was not only to present an overview of the identified roles of PELNVs in physiology and pathology, but also to provide new insight toward their engineering for effective therapeutics and drug delivery nanoplatforms, a clue for future direction to the ongoing research gaps.

64Cu-labeling of small extracellular vesicle surfaces via a cross-bridged macrocyclic chelator for pharmacokinetic study by positron emission tomography imaging

We developed a method of labeling the surfaces of small extracellular vesicles (sEVs) with ⁶⁴Cu using a cross-bridged, macrocyclic chelator (CB-TE1A1P) and applied to pharmacokinetics study with positron emission tomography (PET). After incubation in 20% plasma for 10 min, approximately a half of the ⁶⁴Cu was desorbed from ⁶⁴Cu-labeled sEVs purified by phosphate-buffered saline wash, suggesting partly weak interaction without coordinating to CB-TE1A1P. After subsequent purification with albumin, ⁶⁴Cu desorption was greatly reduced, resulting in a radiochemical stability of 95.7%. Notably, labeling did not alter the physicochemical and biological properties of sEVs. After intravenous injection, ⁶⁴Cu-labeled sEVs rapidly disappeared from the systemic blood circulation and accumulated mainly in the liver and spleen of macrophage-competent mice. In macrophage-depleted mice, ⁶⁴Cu-labeled sEVs remained in the blood circulation for a longer period and gradually accumulated in the liver and spleen, suggesting mechanisms of hepatic and splenic accumulation other than macrophage-dependent phagocytosis. The comparison of tissue uptake clearance between macrophage-competent and macrophage-depleted mice suggests that macrophages contributed to 67% and 76% of sEV uptake in the liver and spleen, respectively. The application of this method in pharmacokinetics PET studies can be useful in preclinical and clinical research and the development of sEV treatment modalities.

Low-Stiffness Hydrogels Promote Peripheral Nerve Regeneration Through the Rapid Release of Exosomes

A hydrogel system loaded with mesenchymal stem cell–derived exosome (MSC-Exos) is an attractive new tool for tissue regeneration. However, the effect of the stiffness of exosome-loaded hydrogels on tissue regeneration is unclear. Here, the role of exosome-loaded hydrogel stiffness, during the regeneration of injured nerves, was assessed in vivo. The results showed that the photocrosslinkable hyaluronic acid methacrylate hydrogel stiffness plays an important role in repairing nerve injury. Compared with the stiff hydrogels loaded with exosomes, soft hydrogels loaded with exosomes showed better repair of injured peripheral nerves. The soft hydrogel promoted nerve repair by quickly releasing exosomes to inhibit the infiltration of macrophages and the expression of the proinflammatory factors IL-1β and TNF-α in injured nerves. Our work revealed that exosome-loaded hydrogel stiffness plays an important role in tissue regeneration by regulating exosome release behavior and provided important clues for the clinical application of biological scaffold materials.

Diabetes complications and extracellular vesicle therapy

Diabetes is a chronic disorder characterized by dysregulated glycemic conditions. Diabetic complications include microvascular and macrovascular abnormalities and account for high morbidity and mortality rates in patients. Current clinical approaches for diabetic complications are limited to symptomatic treatments and tight control of blood sugar levels. Extracellular vesicles (EVs) released by somatic and stem cells have recently emerged as a new class of potent cell-free therapeutic delivery packets with a great potential to treat diabetic complications. EVs contain a mixture of bioactive molecules and can affect underlying pathological processes in favor of tissue healing. In addition, EVs have low immunogenicity and high storage capacity while maintaining nearly the same regenerative and immunomodulatory effects compared to current cell-based therapies. Therefore, EVs have received increasing attention for diabetes-related complications in recent years. In this review, we provide an outlook on diabetic complications and summarizes new knowledge and advances in EV applications. Moreover, we highlight recommendations for future EV-related research.

Raman Microspectroscopy Imaging Analysis of Extracellular Vesicles Biogenesis by Filamentous Fungus Penicilium chrysogenum

The mechanism of production of extracellular vesicles (EVs) and their molecular contents are of great interest due to their diverse roles in biological systems and are far from being completely understood. Even though cellular cargo releases mediated by EVs have been demonstrated in several cases, their role in secondary metabolite production and release remains elusive. In this study, this aspect is investigated in detail using Raman microspectroscopic imaging. Considerable evidence is provided to suggest that the release of antibiotic penicillin by the filamentous fungus Penicillium chrysogenum involves EVs. Further, the study also reveals morphological modifications of the fungal body during biogenesis, changes in cell composition at the locus of biogenesis, and major molecular contents of the released EVs. The results suggest a possible general role of EVs in the release of antibiotics from the producing organisms.

Engineering extracellular vesicles by three-dimensional dynamic culture of human mesenchymal stem cells

Human mesenchymal stem cell (hMSC) derived extracellular vesicles (EVs) have shown therapeutic potential in recent studies. However, the corresponding therapeutic components are largely unknown, and scale-up production of hMSC EVs is a major challenge for translational applications. In the current study, hMSCs were grown as 3D aggregates under wave motion to promote EV secretion. Results demonstrate that 3D hMSC aggregates promote activation of the endosomal sorting complexes required for transport (ESCRT)-dependent and -independent pathways. mRNA sequencing revealed global transcriptome alterations for 3D hMSC aggregates. Compared to 2D-hMSC-EVs, the quantity of 3D-hMSC-EVs was enhanced significantly (by 2-fold), with smaller sizes, higher miR-21 and miR-22 expression, and an altered protein cargo (e.g., upregulation of cytokines and anti-inflammatory factors) uncovered by proteomics analysis, possibly due to altered EV biogenesis. Functionally, 3D-hMSC-EVs rejuvenated senescent stem cells and exhibited enhanced immunomodulatory potentials. In summary, this study provides a promising strategy for scalable production of high-quality EVs from hMSCs with enhanced therapeutic potential.

MicroRNAs: Novel players in the diagnosis and treatment of cancer cachexia (Review)

Cachexia denotes a complex metabolic syndrome featuring severe loss of weight, fatigue and anorexia. In total, 50-80% of patients suffering from advanced cancer are diagnosed with cancer cachexia, which contributes to 40% of cancer-associated mortalities. MicroRNAs (miRNAs) are non-coding RNAs capable of regulating gene expression. Dysregulated miRNA expression has been observed in muscle tissue, adipose tissue and blood samples from patients with cancer cachexia compared with that of samples from patients with cancer without cachexia or healthy controls. In addition, miRNAs promote and maintain the malignant state of systemic inflammation, while inflammation contributes to cancer cachexia. The present review discusses the role of miRNAs in the progression of cancer cachexia, and assess their diagnostic value and potential therapeutic value.

Characterizing Extracellular Vesicles and Particles Derived from Skeletal Muscle Myoblasts and Myotubes and the Effect of Acute Contractile Activity

Extracellular vesicles (EVs), released from all cells, are essential to cellular communication and contain biomolecular cargo that can affect recipient cell function. Studies on the effects of contractile activity (exercise) on EVs usually rely on plasma/serum-based assessments, which contain EVs from many different cells. To specifically characterize skeletal muscle−derived vesicles and the effect of acute contractile activity, we used an in vitro model where C2C12 mouse myoblasts were differentiated to form myotubes. EVs were isolated from conditioned media from muscle cells at pre-differentiation (myoblasts) and post-differentiation (myotubes) and also from acutely stimulated myotubes (1 h @ 14 V, C-Pace EM, IonOptix, Westwood, MA, USA) using total exosome isolation reagent (TEI, ThermoFisher (Waltham, MA, USA), referred to as extracellular particles [EPs]) and differential ultracentrifugation (dUC; EVs). Myotube-EPs (~98 nm) were 41% smaller than myoblast-EPs (~167 nm, p < 0.001, n = 8−10). Two-way ANOVA showed a significant main effect for the size distribution of myotube vs. myoblast-EPs (p < 0.01, n = 10−13). In comparison, myoblast-EPs displayed a bimodal size distribution profile with peaks at <200 nm and 400−600, whereas myotube-Eps were largely 50−300 nm in size. Total protein yield from myotube-EPs was nearly 15-fold higher than from the myoblast-EPs, (p < 0.001 n = 6−9). Similar biophysical characteristics were observed when EVs were isolated using dUC: myotube-EVs (~195 nm) remained 41% smaller in average size than myoblast-EVs (~330 nm, p = 0.07, n = 4−6) and had comparable size distribution profiles to EPs isolated via TEI. Myotube-EVs also had 4.7-fold higher protein yield vs. myoblast EVs (p < 0.05, n = 4−6). Myotube-EPs exhibited significantly decreased expression of exosomal marker proteins TSG101, CD63, ALIX and CD81 compared with myoblast-EPs (p < 0.05, n = 7−12). Conversely, microvesicle marker ARF6 and lipoprotein marker APO-A1 were only found in the myotube-EPs (p < 0.05, n = 4−12). There was no effect of acute stimulation on myotube-EP biophysical characteristics (n = 7) or on the expression of TSG101, ARF6 or CD81 (n = 5−6). Myoblasts treated with control or acute stimulation−derived EPs (13 µg/well) for 48 h and 72 h showed no changes in mitochondrial mass (MitoTracker Red, ThermoFisher, Waltham, MA, USA), cell viability or cell count (n = 3−4). Myoblasts treated with EP-depleted media (72 h) exhibited ~90% lower cell counts (p < 0.01, n = 3). Our data show that EVs differed in size, distribution, protein yield and expression of subtype markers pre vs. post skeletal muscle−differentiation into myotubes. There was no effect of acute stimulation on biophysical profile or protein markers in EPs. Acute stimulation−derived EPs did not alter mitochondrial mass or cell count/viability. Further investigation into the effects of chronic contractile activity on the biophysical characteristics and cargo of skeletal muscle−specific EVs are warranted.

Update on the role and utility of extracellular vesicles in hematological malignancies

Extracellular vesicles (EVs) are membrane-surrounded cellular particles released by virtually any cell type, containing numerous bioactive molecules, including lipids, proteins, and nucleic acids. EVs act as a very efficient intercellular communication system by releasing their content into target cells, thus affecting their fate and influencing several biological processes. EVs are released both in physiological and pathological conditions, including several types of cancers. In hematological malignancies (HM), EVs have emerged as new critical players, contributing to tumor-to-stroma, stroma-to-tumor, and tumor-to-tumor cell communication. Therefore, EVs have been shown to play a crucial role in the pathogenesis and clinical course of several HM, contributing to tumor development, progression, and drug resistance. Furthermore, tumor EVs can reprogram the bone marrow (BM) microenvironment and turn it into a sanctuary, in which cancer cells suppress both the normal hematopoiesis and the immunological anti-tumor activity, conferring a therapy-resistant phenotype. Due to their physicochemical characteristics and pro-tumor properties, EVs have been suggested as new diagnostic biomarkers, therapeutic targets, and pharmacological nanocarriers. This review aims to provide an update on the pathogenetic contribution and the putative therapeutic utility of EVs in hematological diseases.

Current and Developing Liquid Biopsy Techniques for Breast Cancer

Breast cancer is the most commonly diagnosed cancer and leading cause of cancer mortality among woman worldwide. The techniques of diagnosis, prognosis, and therapy monitoring of breast cancer are critical. Current diagnostic techniques are mammography and tissue biopsy; however, they have limitations. With the development of novel techniques, such as personalized medicine and genetic profiling, liquid biopsy is emerging as the less invasive tool for diagnosing and monitoring breast cancer. Liquid biopsy is performed by sampling biofluids and extracting tumor components, such as circulating tumor cells (CTCs), circulating tumor DNA (ctDNA), cell-free mRNA (cfRNA) and microRNA (miRNA), proteins, and extracellular vehicles (EVs). In this review, we summarize and focus on the recent discoveries of tumor components and biomarkers applied in liquid biopsy and novel development of detection techniques, such as surface-enhanced Raman spectroscopy (SERS) and microfluidic devices.

Extracellular Vesicle Therapy for Type 1 Diabetes

Type 1 diabetes (T1D) is a chronic disorder characterized by immune-mediated destruction of pancreatic insulin-producing β-cells. The primary treatment for T1D is multiple daily insulin injections to control blood sugar levels. Cell-free delivery packets with therapeutic properties, extracellular vesicles (EVs), mainly from stem cells, have recently gained considerable attention for disease treatments. EVs provide a great potential to treat T1D ascribed to their regenerative, anti-inflammatory, and immunomodulatory effects. Here, we summarize the latest EV applications for T1D treatment and highlight opportunities for further investigation.

Extracellular Vesicle-Mediated Delivery of Ultrasmall Superparamagnetic Iron Oxide Nanoparticles to Mice Brain

Extracellular vesicles (EVs) are small lipid membrane-bound vesicles that can pass the blood–brain barrier. Therefore, EVs could be used for the delivery of therapeutics to the brain. Herein, we investigated the biodistribution of intranasal perfusion of ultrasmall superparamagnetic iron oxide (USPIO)-labeled astrocyte-derived EVs (ADEVs) in mice. We used Western blotting, transmission electron microscopy (TEM), and nanoparticle uptake assay to characterize ADEVs. In addition, intranasal perfusion coupled with magnetic resonance imaging (MRI) was employed to determine the distribution of USPIO-labeled ADEVs in mice. Our results showed the uptake of USPIO by mouse astrocytes and ADEVs. In addition, we confirmed the biodistribution of ADEVs in the brain and other internal organs, including the kidneys, liver, and spleen. Our results suggest that USPIO did not affect mouse astrocyte cell survivability and EV release. Therefore, intranasal delivery of therapeutic loaded EVs could be used for the treatment of various brain disorders.

Exosome-Laden Hydrogels: A Novel Cell-free Strategy for In-situ Bone Tissue Regeneration

In-situ bone tissue regeneration, which harnesses cell external microenvironment and their regenerative potential to induce cell functions and bone reconstruction through some special properties of biomaterials, has been deeply developed. In which, hydrogel was widely applied due to its 3D network structure with high water absorption and mimicking native extracellular matrix (ECM). Additionally, exosomes can participate in a variety of physiological processes such as cell differentiation, angiogenesis and tissue repair. Therefore, a novel cell-free tissue engineering (TE) using exosome-laden hydrogels has been explored and developed for bone regeneration in recent years. However, related reviews in this field are limited. Therefore, we elaborated on the shortcomings of traditional bone tissue engineering, the challenges of exosome delivery and emphasized the advantages of exosome-laden hydrogels for in-situ bone tissue regeneration. The encapsulation strategies of hydrogel and exosomes are listed, and the research progress and prospects of bioactive hydrogel composite system for continuous delivery of exosomes for in-situ bone repair are also discussed in this review.

Chemically Modified Extracellular Vesicles and Applications in Radiolabeling and Drug Delivery

Extracellular vesicles (EVs) have been exploited as bio-inspired drug delivery systems (DDS) in the biomedical field. EVs have more advantages than synthetic nanoparticles: they are naturally equipped to cross extra- and intra-cellular barriers. Furthermore, they can deliver functional biomolecules from one cell to another even far away in the body. These advantages, along with obtained promising in vivo results, clearly evidenced the potential of EVs in drug delivery. Nevertheless, due to the difficulties of finding a chemical approach that is coherent with EVs’ rational clinical therapeutic use, those in the drug delivery community are expecting more from EVs’ use. Therefore, this review gathered knowledge of the current chemical approaches dealing with the conjugation of EVs for drugs and radiotracers.

Proteomic Analysis of Plasma-Derived Extracellular Vesicles From Mice With Echinococcus granulosus at Different Infection Stages and Their Immunomodulatory Functions

The globally distributed cystic echinococcosis (CE) is caused by the larval stage of Echinococcus granulosus (E. granulosus), a cosmopolitan and zoonotic disease with potentially life-threatening complications in humans. The emerging roles for extracellular vesicles (EVs) in parasitic infection include transferring proteins and modifying host cell gene expression to modulate host immune responses. Few studies focused on the host-derived EVs and its protein profiles. We focused on the EVs from mouse infected with E. granulosus at different stages. ExoQuick kit was used for isolating EVs from mouse plasma and ExoEasy Maxi kit was used for isolating protoscolex culture supernatant (PCS) and hydatid cyst fluid (HCF). Firstly, EVs were characterized by transmission electron microscopy (TEM), nanoparticle tracking analysis (NTA) and immunoblot. Secondly, the proteins of plasma EVs were identified using liquid chromatography-tandem mass spectrometry (LC–MS/MS). The resulting LC–MS/MS data were processed using Maxquant search engine (v 1.5.2.8). Tandem mass spectra were researched against the mice and E. granulosus proteins database in the NCBI. The differentially expressed proteins are performed by proteomic label-free quantitative analysis and bioinformatics. Thirdly, in vitro experiment, the results of co-culture of plasma EVs and spleen mononuclear cells showed that 7W-EVs can increase the relative abundance of regulatory T (Treg) cells and IL-10. We further verified that EVs can be internalized by CD4⁺ and CD8⁺ T cells, B cells, and myeloid-derived suppressor cells (MDSC). These results implied host-derived EVs are multidirectional immune modulators. The findings can contribute to a better understanding of the role of host-derived EVs which are the optimal vehicle to transfer important cargo into host immune system. In addition, we have found several important proteins associated with E. granulosus and identified in infected mouse plasma at different stages. Furthermore, our study further highlighted the proteomics and immunological function of EVs from mouse infected with E. granulosus protoscoleces at different infection stages. We have laid a solid foundation for the role of EVs in cystic echinococcosis in the future research and supplemented a unique dataset for this E. granulosus.

Vesicle-based artificial cells: materials, construction methods and applications

The construction of artificial cells with specific cell-mimicking functions helps to explore complex biological processes and cell functions in natural cell systems and provides an insight into the origins of life. Bottom-up methods are widely used for engineering artificial cells based on vesicles by the in vitro assembly of biomimetic materials. In this review, the design of artificial cells with a specific function is discussed, by considering the selection of synthetic materials and construction technologies. First, a range of biomimetic materials for artificial cells is reviewed, including lipid, polymeric and hybrid lipid/copolymer materials. Biomaterials extracted from natural cells are also covered in this part. Then, the formation of microscale, giant unilamellar vesicles (GUVs) is reviewed based on different technologies, including gentle hydration, electro-formation, phase transfer and microfluidic methods. Subsequently, applications of artificial cells based on single vesicles or vesicle networks are addressed for mimicking cell behaviors and signaling processes. Microreactors for synthetic biology and cell-cell communication are highlighted here as well. Finally, current challenges and future trends for the development and applications of artificial cells are described.