Safety evaluation of exosomes derived from human umbilical cord mesenchymal stromal cell

Enhancing precision targeting of ovarian cancer tumor cells in vivo through extracellular vesicle engineering

Extracellular vesicles (EVs) function as natural mediators of intercellular communication, secreted by cells to facilitate cell-cell signaling. Due to their low toxicity, immunogenicity, biodegradability, and potential to encapsulate therapeutic drugs, EVs hold significant therapeutic promise. Nevertheless, their limited targeting ability often diminishes their therapeutic impact. Therefore, enhancing EVs by incorporating targeting units onto their membranes could bolster their targeting capabilities, enabling them to accumulate in specific cells and tissues. In this study, we engineered EVs to fuse ephrin-B2 with the EV membrane protein LAMP2b. This modification aimed to direct the engineered EVs toward the ephrin-B4 receptor expressed on the surface of ovarian cancer cells. The engineered EVs retained their inherent properties, including size, expression of EV membrane proteins, and morphology, upon isolation. In vitro experiments using real-time imaging revealed that EVs engineered with the ephrin-B2 ligand exhibited substantial internalization and uptake by ovarian cancer cells, in stark contrast to native EVs. In vivo, the engineered EVs carrying the ephrin-B2 ligand effectively targeted ovarian cancer cells, surpassing the targeting efficiency of control EVs. This innovative approach establishes a novel targeting system, enhancing the uptake of EVs by ovarian cancer cells. Our findings underscore the potential of using EVs to target cancer cells, thereby enhancing the effectiveness of anti-cancer therapies while minimizing off-target effects and toxicity in normal cells and organs.

Recent progress in gene therapy for familial hypercholesterolemia treatment

Familial hypercholesterolemia (FH) is a genetic disorder that affects 1 in 300 people, leading to high cholesterol levels and significantly increased cardiovascular risk. The limitations of existing FH treatments underscore the need for innovative therapeutics, and gene therapy offers a promising alternative to address FH more effectively. In this review, we survey approved gene therapy drugs first and then delve into the landscape of gene addition, gene inactivation, and gene editing therapies for hypercholesterolemia, highlighting both approved interventions and those in various stages of development. We also discussed recent advancements in gene editing tools that are essential for their application in gene therapy. Safety considerations inherent to gene therapy are also discussed, emphasizing the importance of mitigating potential risks associated with such treatments. Overall, this review highlights the progress and prospects of gene therapies for FH treatments, underscoring their potential to revolutionize the management of this prevalent and challenging condition.

Advancements in extracellular vesicle targeted therapies for rheumatoid arthritis: insights into cellular origins, current perspectives, and emerging challenges

Rheumatoid arthritis (RA) remains a challenging chronic autoimmune disorder characterized by persistent joint inflammation and damage. While modern regenerative strategies, encompassing cell/stem cell-based therapies, gene therapy, and tissue engineering, have advanced tissue repair efforts, a definitive cure for RA remains elusive. Consequently, there is growing interest in developing targeted therapies that directly address the underlying mechanisms driving RA pathogenesis, such as extracellular vesicles (EVs). These small membrane-bound particles can modulate immune responses within the inflammatory microenvironment of damaged cartilage. To launch the clinical potential of EVs, they can be isolated from various cell types through several techniques. EVs can carry various bioactive molecules and anti-inflammatory or pro-regenerative drugs, deliver them directly to the affected joints, and affect the behavior of injured cells, making them a compelling choice for targeted therapy and drug delivery in RA patients. However, there are still several challenges and limitations associated with EV-based therapy, including the absence of standardized protocols for EV isolation, characterization, and delivery. This review provides a comprehensive overview of the cellular sources of EVs in RA and delves into their therapeutic potential and the hurdles they must overcome.

GMP-compliant extracellular vesicles derived from umbilical cord mesenchymal stromal cells: manufacturing and pre-clinical evaluation in ARDS treatment

BACKGROUND AIMS

Extracellular vesicles (EVs) represent a new axis of intercellular communication that can be harnessed for therapeutic purposes, as cell-free therapies. The clinical application of mesenchymal stromal cell (MSC)-derived EVs, however, is still in its infancy and faces many challenges. The heterogeneity inherent to MSCs, differences among donors, tissue sources, and variations in manufacturing conditions may influence the release of EVs and their cargo, thus potentially affecting the quality and consistency of the final product. We investigated the influence of cell culture and conditioned medium harvesting conditions on the physicochemical and proteomic profile of human umbilical cord MSC-derived EVs (hUCMSC-EVs) produced under current good manufacturing practice (cGMP) standards. We also evaluated the efficiency of the protocol in terms of yield, purity, productivity, and expression of surface markers, and assessed the biodistribution, toxicity and potential efficacy of hUCMSC-EVs in pre-clinical studies using the LPS-induced acute lung injury model.

METHODS

hUCMSCs were isolated from a cord tissue, cultured, cryopreserved, and characterized at a cGMP facility. The conditioned medium was harvested at 24, 48, and 72 h after the addition of EV collection medium. Three conventional methods (nanoparticle tracking analysis, transmission electron microscopy, and nanoflow cytometry) and mass spectrometry were used to characterize hUCMSC-EVs. Safety (toxicity of single and repeated doses) and biodistribution were evaluated in naive mice after intravenous administration of the product. Efficacy was evaluated in an LPS-induced acute lung injury model.

RESULTS

hUCMSC-EVs were successfully isolated using a cGMP-compliant protocol. Comparison of hUCMSC-EVs purified from multiple harvests revealed progressive EV productivity and slight changes in the proteomic profile, presenting higher homogeneity at later timepoints of conditioned medium harvesting. Pooled hUCMSC-EVs showed a non-toxic profile after single and repeated intravenous administration to naive mice. Biodistribution studies demonstrated a major concentration in liver, spleen and lungs. HUCMSC-EVs reduced lung damage and inflammation in a model of LPS-induced acute lung injury.

CONCLUSIONS

hUCMSC-EVs were successfully obtained following a cGMP-compliant protocol, with consistent characteristics and pre-clinical safety profile, supporting their future clinical development as cell-free therapies.

Immunogenicity of Extracellular Vesicles

Extracellular vesicles (EVs) are promising next-generation therapeutics and drug delivery systems due to demonstrated safety and efficacy in preclinical models and early-stage clinical trials. There is an urgent need to address the immunogenicity of EVs (beyond the apparent lack of immunotoxicity) to advance clinical development. To date, few studies have assessed unintended immunological recognition of EVs. An in-depth understanding of EV-induced immunogenicity and clearance is necessary to develop effective therapeutic strategies, including approaches to mitigate immunological recognition when undesired. This article summarizes various factors involved in the potential immunogenicity of EVs and strategies to reduce immunological recognition for improved therapeutic benefit.

Exosome prospects in the diagnosis and treatment of non-alcoholic fatty liver disease

The growing prevalence of NAFLD and its global health burden have provoked considerable research on possible diagnostic and therapeutic options for NAFLD. Although various pathophysiological mechanisms and genetic factors have been identified to be associated with NAFLD, its treatment remains challenging. In recent years, exosomes have attracted widespread attention for their role in metabolic dysfunctions and their efficacy as pathological biomarkers. Exosomes have also shown tremendous potential in treating a variety of disorders. With increasing evidence supporting the significant role of exosomes in NAFLD pathogenesis, their theragnostic potential has become a point of interest in NAFLD. Expectedly, exosome-based treatment strategies have shown promise in the prevention and amelioration of NAFLD in preclinical studies. However, there are still serious challenges in preparing, standardizing, and applying exosome-based therapies as a routine clinical option that should be overcome. Due to the great potential of this novel theragnostic agent in NAFLD, further investigations on their safety, clinical efficacy, and application standardization are highly recommended.

Therapeutic role of extracellular vesicles from human umbilical cord mesenchymal stem cells and their wide therapeutic implications in inflammatory bowel disease and other inflammatory disorder

The chronic immune-mediated inflammatory condition known as inflammatory bowel disease (IBD) significantly affects the gastrointestinal system. While the precise etiology of IBD remains elusive, extensive research suggests that a range of pathophysiological pathways and immunopathological mechanisms may significantly contribute as potential factors. Mesenchymal stem cells (MSCs) have shown significant potential in the development of novel therapeutic approaches for various medical conditions. However, some MSCs have been found to exhibit tumorigenic characteristics, which limit their potential for medical treatments. The extracellular vesicles (EVs), paracrine factors play a crucial role in the therapeutic benefits conferred by MSCs. The EVs consist of proteins, microRNAs, and lipids, and are instrumental in facilitating intercellular communication. Due to the ease of maintenance, and decreased immunogenicity, tumorigenicity the EVs have become a new and exciting option for whole cell treatment. This review comprehensively assesses recent preclinical research on human umbilical cord mesenchymal stem cell (hUC-MSC)-derived EVs as a potential IBD therapy. It comprehensively addresses key aspects of various conditions, including diabetes, cancer, dermal injuries, neurological disorders, cardiovascular issues, liver and kidney diseases, and bone-related afflictions.

Non-Clinical Safety Evaluation of Exosomes Derived from Human Umbilical Cord Mesenchymal Stem Cells in Cynomolgus Monkeys

Purpose

In recent years, exosomes have been proved to be used to treat many diseases. However, due to the lack of uniform quality control standards for exosomes, the safety of exosomes is still a problem to be solved, especially now more and more exosomes are used in clinical trials, and its non-clinical safety evaluation is particularly important. However, there is no safety evaluation standard for exosomes at present. Therefore, this study will refer to the evaluation criteria of therapeutic biological products, adopt non-human primates to evaluate the non-clinical safety of human umbilical cord mesenchymal stem cell exosomes from the general pharmacology and immunotoxicity, aiming at establishing a safety evaluation system of exosomes and providing reference for the clinical application of exosomes in the future.

Methods

3.85 × 1012 exosomes derived from human umbilical cord mesenchymal stem cells were injected into cynomolgus monkeys intravenously. The changes of general clinical conditions, hematology, immunoglobulin, Th1/Th2 cytokines, T lymphocytes and B lymphocytes, and immune organs were observed before and within 14 days after injection.

Results

The results showed that exosomes did not have obvious pathological effects on the general clinical conditions, blood, coagulation function, organ coefficient, immunoglobulin, Th1/Th2 cytokines, lymphocytes, major organs, and major immune organs (spleen, thymus, bone marrow) of cynomolgus monkeys. However, the number of granulocyte-macrophage colonies in exosomes group was significantly higher than that in control group.

Conclusion

To sum up, the general pharmacological results and immunotoxicity results showed that the injection of 3.85 × 1012 exosomes may have no obvious adverse reactions to cynomolgus monkeys. This dose of exosomes is relatively safe for treatment, which provides basis research for non-clinical safety evaluation of exosomes and provides reliable research basis for future clinical application of exosomes.

The Role of Extracellular Vesicles in the Treatment of Prostate Cancer

Prostate cancer (PCa) has become a public health concern in elderly men due to an ever-increasing number of estimated cases. Unfortunately, the available treatments are unsatisfactory because of a lack of a durable response, especially in advanced disease states. Extracellular vesicles (EVs) are lipid-bilayer encircled nanoscale vesicles that carry numerous biomolecules (e.g., nucleic acids, proteins, and lipids), mediating the transfer of information. The past decade has witnessed a wide range of EV applications in both diagnostics and therapeutics. First, EV-based non-invasive liquid biopsies provide biomarkers in various clinical scenarios to guide treatment; EVs can facilitate the grading and staging of patients for appropriate treatment selection. Second, EVs play a pivotal role in pathophysiological processes via intercellular communication. Targeting key molecules involved in EV-mediated tumor progression (e.g., proliferation, angiogenesis, metastasis, immune escape, and drug resistance) is a potential approach for curbing PCa. Third, EVs are promising drug carriers. Naïve EVs from various sources and engineered EV-based drug delivery systems have paved the way for the development of new treatment modalities. This review discusses the recent advancements in the application of EV therapies and highlights EV-based functional materials as novel interventions for PCa.

Exosomes Derived from Bone Marrow Mesenchymal Stem Cells Alleviate Rheumatoid Arthritis Symptoms via Shuttling Proteins

Our prior investigations have evidenced that bone marrow mesenchymal stem cell (BMSC) therapy can significantly improve the outcomes of rheumatoid arthritis (RA). This study aims to conduct a comprehensive analysis of the proteomics between BMSCs and BMSCs-Exos, and to further elucidate the potential therapeutic effect of BMSCs-Exos on RA, so as to establish a theoretical framework for the prevention and therapy of BMSCs-Exos on RA. The 4D label-free LC-MS/MS technique was used for comparative proteomic analysis of BMSCs and BMSCs-Exos. Collagen-induced arthritis (CIA) rat model was used to investigate the therapeutic effect of BMSCs-Exos on RA. Our results showed that some homology and differences were observed between BMSCs and BMSCs-Exos proteins, among which proteins highly enriched in BMSCs-Exos were related to extracellular matrix and extracellular adhesion. BMSCs-Exos can be taken up by chondrocytes, promoting cell proliferation and migration. In vivo results revealed that BMSCs-Exos significantly improved the clinical symptoms of RA, showing a certain repair effect on the injury of articular cartilage. In short, our study revealed, for the first time, that BMSCs-Exos possess remarkable efficacy in alleviating RA symptoms, probably through shuttling proteins related to cell adhesion and tissue repair ability in CIA rats, suggesting that BMSCs-Exos carrying expressed proteins may become a useful biomaterial for RA treatment.

Transcriptome analysis reveals therapeutic potential of NAMPT in protecting against abdominal aortic aneurysm in human and mouse

Abdominal Aortic Aneurysm (AAA) is a life-threatening vascular disease characterized by the weakening and ballooning of the abdominal aorta, which has no effective therapeutic approaches due to unclear molecular mechanisms. Using single-cell RNA sequencing, we analyzed the molecular profile of individual cells within control and AAA abdominal aortas. We found cellular heterogeneity, with increased plasmacytoid dendritic cells and reduced endothelial cells and vascular smooth muscle cells (VSMCs) in AAA. Up-regulated genes in AAA were associated with muscle tissue development and apoptosis. Genes controlling VSMCs aberrant switch from contractile to synthetic phenotype were significantly enriched in AAA. Additionally, VSMCs in AAA exhibited cell senescence and impaired oxidative phosphorylation. Similar observations were made in a mouse model of AAA induced by Angiotensin II, further affirming the relevance of our findings to human AAA. The concurrence of gene expression changes between human and mouse highlighted the impairment of oxidative phosphorylation as a potential target for intervention. Nicotinamide phosphoribosyltransferase (NAMPT, also named VISFATIN) signaling emerged as a signature event in AAA. NAMPT was significantly downregulated in AAA. NAMPT-extracellular vesicles (EVs) derived from mesenchymal stem cells restored NAMPT levels, and offered protection against AAA. Furthermore, NAMPT-EVs not only repressed injuries, such as cell senescence and DNA damage, but also rescued impairments of oxidative phosphorylation in both mouse and human AAA models, suggesting NAMPT supplementation as a potential therapeutic approach for AAA treatment. These findings shed light on the cellular heterogeneity and injuries in AAA, and offered promising therapeutic intervention for AAA treatment.

The role of extracellular vesicles in COPD and potential clinical value

Chronic obstructive pulmonary disease (COPD) is a heterogeneous lung disease and a major health burden worldwide. Extracellular vesicles (EVs) are nanosized vesicles which possess a lipid bilayer structure that are secreted by various cells. They contain a variety of bioactive substances, which can regulate various physiological and pathological processes and are closely related to the development of diseases. Recently, EVs have emerged as a novel tool for intercellular crosstalk, which plays an essential role in COPD development. This paper reviews the role of EVs in the development of COPD and their potential clinical value, in order to provide a reference for further research on COPD.

Mesenchymal stem cell-derived exosomes: a promising alternative in the therapy of preeclampsia

Preeclampsia (PE) is a common morbid complication during pregnancy, affecting 2%-8% of pregnancies globally and posing serous risks to the health of both mother and fetus. Currently, the only effective treatment for PE is timely termination of pregnancy, which comes with increased perinatal risks. However, there is no effective way to delay pathological progress and improve maternal and fetal outcomes. In light of this, it is of great significance to seek effective therapeutic strategies for PE. Exosomes which are nanoparticles carrying bioactive substances such as proteins, lipids, and nucleic acids, have emerged as a novel vehicle for intercellular communication. Mesenchymal stem cell-derived exosomes (MSC-Exos) participate in various important physiological processes, including immune regulation, cell proliferation and migration, and angiogenesis, and have shown promising potential in tissue repair and disease treatment. Recently, MSC-Exos therapy has gained popularity in the treatment of ischaemic diseases, immune dysfunction, inflammatory diseases, and other fields due to their minimal immunogenicity, characteristics similar to donor cells, ease of storage, and low risk of tumor formation. This review elaborates on the potential therapeutic mechanism of MSC-Exos in treating preeclampsia, considering the main pathogenic factors of the condition, including placental vascular dysplasia, immunological disorders, and oxidative stress, based on the biological function of MSC-Exos. Additionally, we discuss in depth the advantages and challenges of MSC-Exos as a novel acellular therapeutic agent in preeclampsia treatment.

Effects of exosomes from mesenchymal stem cells on functional recovery of a patient with total radial nerve injury: A pilot study

BACKGROUND

Peripheral nerve injury can result in significant clinical complications that have uncertain prognoses. Currently, there is a lack of effective pharmacological interventions for nerve damage, despite the existence of several small compounds, peptides, hormones, and growth factors that have been suggested as potential enhancers of neuron regeneration. Despite the objective of achieving full functional restoration by surgical intervention, the persistent challenge of inadequate functional recovery remains a significant concern in the context of peripheral nerve injuries.

AIM

To examine the impact of exosomes on the process of functional recovery following a complete radial nerve damage.

METHODS

A male individual, aged 24, who is right-hand dominant and an immigrant, arrived with an injury caused by a knife assault. The cut is located on the left arm, specifically below the elbow. The neurological examination and electrodiagnostic testing reveal evidence of left radial nerve damage. The sural autograft was utilized for repair, followed by the application of 1 mL of mesenchymal stem cell-derived exosome, comprising 5 billion microvesicles. This exosome was split into four equal volumes of 0.25 mL each and delivered microsurgically to both the proximal and distal stumps using the subepineural pathway. The patient was subjected to a period of 180 d during which they had neurological examination and electrodiagnostic testing.

RESULTS

The duration of the patient's follow-up period was 180 d. An increasing Tinel's sign and sensory-motor recovery were detected even at the 10th wk following nerve grafting. Upon the conclusion of the 6-mo post-treatment period, an evaluation was conducted to measure the extent of improvement in motor and sensory functions of the nerve. This assessment was based on the British Medical Research Council scale and the Mackinnon-Dellon scale. The results indicated that the level of improvement in motor function was classified as M5, denoting an excellent outcome. Additionally, the level of improvement in sensory function was classified as S3+, indicating a good outcome. It is noteworthy that these assessments were conducted in the absence of physical therapy. At the 10th wk post-injury, despite the persistence of substantial axonal damage, the nerve exhibited indications of nerve re-innervation as evidenced by control electromyography (EMG). In contrast to the preceding. EMG analysis revealed a significant electrophysiological enhancement in the EMG conducted at the 6th-mo follow-up, indicating ongoing regeneration.

CONCLUSION

Enhanced comprehension of the neurobiological ramifications associated with peripheral nerve damage, as well as the experimental and therapy approaches delineated in this investigation, holds the potential to catalyze future clinical progress.

Preparation of genetically or chemically engineered exosomes and their therapeutic effects in bone regeneration and anti-inflammation

The treatment of bone or cartilage damage and inflammation-related diseases has been a long-standing research hotspot. Traditional treatments such as surgery and cell therapy have only displayed limited efficacy because they can't avoid potential deterioration and ensure cell activity. Recently, exosomes have become a favorable tool for various tissue reconstruction due to their abundant content of proteins, lipids, DNA, RNA and other substances, which can promote bone regeneration through osteogenesis, angiogenesis and inflammation modulation. Besides, exosomes are also promising delivery systems because of stability in the bloodstream, immune stealth capacity, intrinsic cell-targeting property and outstanding intracellular communication. Despite having great potential in therapeutic delivery, exosomes still show some limitations in clinical studies, such as inefficient targeting ability, low yield and unsatisfactory therapeutic effects. In order to overcome the shortcomings, increasing studies have prepared genetically or chemically engineered exosomes to improve their properties. This review focuses on different methods of preparing genetically or chemically engineered exosomes and the therapeutic effects of engineering exosomes in bone regeneration and anti-inflammation, thereby providing some references for future applications of engineering exosomes.

Current progression in application of extracellular vesicles in central nervous system diseases

Early diagnosis and pharmacological treatment of central nervous system (CNS) diseases has been a long-standing challenge for clinical research due to the presence of the blood-brain barrier. Specific proteins and RNAs in brain-derived extracellular vesicles (EVs) usually reflect the corresponding state of brain disease, and therefore, EVs can be used as diagnostic biomarkers for CNS diseases. In addition, EVs can be engineered and fused to target cells for delivery of cargo, demonstrating the great potential of EVs as a nanocarrier platform. We review the progress of EVs as markers and drug carriers in the diagnosis and treatment of neurological diseases. The main areas include visual imaging, biomarker diagnosis and drug loading therapy for different types of CNS diseases. It is hoped that increased knowledge of EVs will facilitate their clinical translation in CNS diseases.

Reconstituted Extracellular Vesicles from Human Platelets Decrease Viral Myocarditis in Mice

Patients with viral myocarditis are at risk of sudden death and may progress to dilated cardiomyopathy (DCM). Currently, no disease-specific therapies exist to treat viral myocarditis. Here it is examined whether reconstituted, lyophilized extracellular vesicles (EVs) from platelets from healthy men and women reduce acute or chronic myocarditis in male mice. Human-platelet-derived EVs (PEV) do not cause toxicity, damage, or inflammation in naïve mice. PEV administered during the innate immune response significantly reduces myocarditis with fewer epidermal growth factor (EGF)-like module-containing mucin-like hormone receptor-like 1 (F4/80) macrophages, T cells (cluster of differentiation molecules 4 and 8, CD4 and CD8), and mast cells, and improved cardiac function. Innate immune mediators known to increase myocarditis are decreased by innate PEV treatment including Toll-like receptor (TLR)4 and complement. PEV also significantly reduces perivascular fibrosis and remodeling including interleukin 1 beta (IL-1β), transforming growth factor-beta 1, matrix metalloproteinase, collagen genes, and mast cell degranulation. PEV given at days 7-9 after infection reduces myocarditis and improves cardiac function. MicroRNA (miR) sequencing reveals that PEV contains miRs that decrease viral replication, TLR4 signaling, and T-cell activation. These data show that EVs from the platelets of healthy individuals can significantly reduce myocarditis and improve cardiac function.

Innovative preconditioning strategies for improving the therapeutic efficacy of extracellular vesicles derived from mesenchymal stem cells in gastrointestinal diseases

Gastrointestinal (GI) diseases have become a global health issue and an economic burden due to their wide distribution, late prognosis, and the inefficacy of recent available medications. Therefore, it is crucial to search for new strategies for their management. In the recent decades, mesenchymal stem cells (MSCs) therapy has attracted attention as a viable option for treating a myriad of GI disorders such as hepatic fibrosis (HF), ulcerative colitis (UC), acute liver injury (ALI), and non-alcoholic fatty liver disease (NAFLD) due to their regenerative and paracrine properties. Importantly, recent studies have shown that MSC-derived extracellular vesicles (MSC-EVs) are responsible for most of the therapeutic effects of MSCs. In addition, EVs have revealed several benefits over their parent MSCs, such as being less immunogenic, having a lower risk of tumour formation, being able to cross biological barriers, and being easier to store. MSC-EVs exhibited regenerative, anti-oxidant, anti-inflammatory, anti-apoptotic, and anti-fibrotic effects in different experimental models of GI diseases. However, a key issue with their clinical application is the maintenance of their stability and efficacy following in vivo transplantation. Preconditioning of MSC-EVs or their parent cells is one of the novel methods used to improve their effectiveness and stability. Herein, we discuss the application of MSC-EVs in several GI disorders taking into account their mechanism of action. We also summarise the challenges and restrictions that need to be overcome to promote their clinical application in the treatment of various GI diseases as well as the recent developments to improve their effectiveness. A representation of the innovative preconditioning techniques that have been suggested for improving the therapeutic efficacy of MSC-EVs in GI diseases. The pathological conditions in various GI disorders (ALI, UC, HF and NAFLD) create a harsh environment for EVs and their parents, increasing the risk of apoptosis and senescence of MSCs and thereby diminishing MSC-EVs yield and restricting their large-scale applications. Preconditioning with pharmacological agents or biological mediators can improve the therapeutic efficacy of MSC-EVs through their adaption to the lethal environment to which they are subjected. This can result in establishment of a more conducive environment and activation of numerous vital trajectories that act to improve the immunomodulatory, reparative and regenerative activities of the derived EVs, as a part of MSCs paracrine system. ALI, acute liver injury; GI diseases, gastrointestinal diseases; HF, hepatic fibrosis; HSP, heat shock protein; miRNA, microRNA; mRNA, messenger RNA; MSC-EVs, mesenchymal stem cell-derived extracellular vesicles; NAFLD, non-alcoholic fatty liver disease; UC, ulcerative colitis.

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.

Applications of engineered exosomes in drugging noncoding RNAs for cancer therapy

Noncoding RNAs (ncRNAs) are engaged in key cell biological and pathological events, and their expression alteration is connected to cancer progression both directly and indirectly. A huge number of studies have mentioned the significant role of ncRNAs in cancer prevention and therapy that make them an interesting subject for cancer therapy. However, there are several limitations, including delivery, uptake, and short half-life, in the application of ncRNAs in cancer treatment. Exosomes are introduced as promising options for the delivery of ncRNAs to the target cells. In this review, we will briefly discuss the application and barriers of ncRNAs. After that we will focus on exosome-based ncRNAs delivery and their advantages as well as the latest achievements in drugging ncRNAs with exosomes.

Clinical Translation of Extracellular Vesicles

Extracellular vesicles (EVs) occur in a variety of bodily fluids and have gained recent attraction as natural materials due to their bioactive surfaces, internal cargo, and role in intercellular communication. EVs contain various biomolecules, including surface and cytoplasmic proteins; and nucleic acids that are often representative of the originating cells. EVs can transfer content to other cells, a process that is thought to be important for several biological processes, including immune responses, oncogenesis, and angiogenesis. An increased understanding of the underlying mechanisms of EV biogenesis, composition, and function has led to an exponential increase in preclinical and clinical assessment of EVs for biomedical applications, such as diagnostics and drug delivery. Bacterium-derived EV vaccines have been in clinical use for decades and a few EV-based diagnostic assays regulated under Clinical Laboratory Improvement Amendments have been approved for use in single laboratories. Though, EV-based products are yet to receive widespread clinical approval from national regulatory agencies such as the United States Food and Drug Administration (USFDA) and European Medicine Agency (EMA), many are in late-stage clinical trials. This perspective sheds light on the unique characteristics of EVs, highlighting current clinical trends, emerging applications, challenges and future perspectives of EVs in clinical use.

Downregulated circPOKE promotes breast cancer metastasis through activation of the USP10-Snail axis

Breast cancer (BC) is the most commonly diagnosed cancer and the leading cause of cancer-related death among females. Metastasis accounts for the majority of BC related deaths. One feasible strategy to solve this challenging problem is to disrupt the capabilities required for tumor metastasis. Herein, we verified a novel metastasis suppressive circRNA, circPOKE in BC. circPOKE was downregulated in primary and metastatic BC tissues and overexpression of circPOKE inhibited the metastatic potential but not the proliferative ability of BC cells in vitro and in vivo. Mechanistically, circPOKE competitively binds to USP10, and reduces its binding to Snail, a key transcriptional regulator of EMT, thereby inhibiting Snail stability via the protein-ubiquitination degradation pathway. In addition, we found that circPOKE could be secreted into the extracellular space via exosomes and that exosome-carried circPOKE significantly inhibited the invasive capabilities of BC cells in vitro and in vivo. Furthermore, the levels of circPOKE, USP10 and Snail are clinically relevant in BC, suggesting that circPOKE may be used as a potential therapeutic target for patients with BC metastasis.

Enhanced wound healing and hemostasis with exosome-loaded gelatin sponges from human umbilical cord mesenchymal stem cells

BACKGROUND

Rapid wound healing remains a pressing clinical challenge, necessitating studies to hasten this process. A promising approach involves the utilization of human umbilical cord mesenchymal stem cells (hUC-MSCs) derived exosomes. The hypothesis of this study was that these exosomes, when loaded onto a gelatin sponge, a common hemostatic material, would enhance hemostasis and accelerate wound healing.

AIM

To investigate the hemostatic and wound healing efficacy of gelatin sponges loaded with hUC-MSCs-derived exosomes.

METHODS

Ultracentrifugation was used to extract exosomes from hUC-MSCs. Nanoparticle tracking analysis (NTA), transmission electron microscopy (TEM), and western blot techniques were used to validate the exosomes. In vitro experiments were performed using L929 cells to evaluate the cytotoxicity of the exosomes and their impact on cell growth and survival. New Zealand rabbits were used for skin irritation experiments to assess whether they caused adverse skin reactions. Hemolysis test was conducted using a 2% rabbit red blood cell suspension to detect whether they caused hemolysis. Moreover, in vivo experiments were carried out by implanting a gelatin sponge loaded with exosomes subcutaneously in Sprague-Dawley (SD) rats to perform biocompatibility tests. In addition, coagulation index test was conducted to evaluate their impact on blood coagulation. Meanwhile, SD rat liver defect hemostasis model and full-thickness skin defect model were used to study whether the gelatin sponge loaded with exosomes effectively stopped bleeding and promoted wound healing.

RESULTS

The NTA, TEM, and western blot experimental results confirmed that exosomes were successfully isolated from hUC-MSCs. The gelatin sponge loaded with exosomes did not exhibit significant cell toxicity, skin irritation, or hemolysis, and they demonstrated good compatibility in SD rats. Additionally, the effectiveness of the gelatin sponge loaded with exosomes in hemostasis and wound healing was validated. The results of the coagulation index experiment indicated that the gelatin sponge loaded with exosomes had significantly better coagulation effect compared to the regular gelatin sponge, and they showed excellent hemostatic performance in a liver defect hemostasis model. Finally, the full-thickness skin defect healing experiment results showed significant improvement in the healing process of wounds treated with the gelatin sponge loaded with exosomes compared to other groups.

CONCLUSION

Collectively, the gelatin sponge loaded with hUC-MSCs-derived exosomes is safe and efficacious for promoting hemostasis and accelerating wound healing, warranting further clinical application.

Systematic review of exosome treatment in hair restoration: Preliminary evidence, safety, and future directions

BACKGROUND

Exosomes are small extracellular vesicles with potential roles in modulating the hair growth cycle and are an emerging therapy for patients with alopecia. In recent years, researchers have made significant progress in deciphering the network of cellular interactions and signaling pathways mediated by the transfer of exosomes. This has opened the door to a wide range of potential therapeutic applications with an increasing focus on its application in precision medicine.

AIM

To evaluate current published evidence, both preclinical and clinical, on the use of exosomes for hair restoration.

METHODS

In January 2023, a systematic search was conducted using PubMed, Embase, and the Cochrane Library. Records were identified, screened, and assessed for eligibility as per the PRISMA guideline.

RESULTS

We identified 16 studies (15 preclinical and 1 clinical) showing varying degrees of efficacy using exosomes derived from sources including adipose-derived stem cells (ADSCs) and dermal papilla cells (DPCs). Applications of exosomes isolated from ADSCs (ADSC-Exo) and DPCs have shown early promising results in preclinical studies corroborated by results obtained from different model systems. Topical ADSC-Exo has been tried successfully in 39 androgenetic alopecia patients demonstrating significant increases in hair density and thickness. No significant adverse reactions associated with exosome treatment have been reported thus far.

CONCLUSIONS

Although current clinical evidence supporting the use of exosome treatment is limited, there is a growing body of evidence suggesting its therapeutic potential. Further studies are warranted to define its mechanism of action, optimize its delivery and efficacy, and to address important safety concerns.

A roadmap from research to clinical testing of mesenchymal stromal cell exosomes in the treatment of psoriasis

The most clinically trialed cells, mesenchymal stromal cells (MSCs), are now known to mainly exert their therapeutic activity through paracrine secretions, which include exosomes. To mitigate potential regulatory concerns on the scalability and reproducibility in the preparations of MSC exosomes, MSC exosomes were produced using a highly characterized MYC-immortalized monoclonal cell line. These cells do not form tumors in athymic nude mice or exhibit anchorage-independent growth, and their exosomes do not carry MYC protein or promote tumor growth. Unlike intra-peritoneal injections, topical applications of MSC exosomes in a mouse model of IMQ-induced psoriasis alleviate interleukin (IL)-17, IL-23 and terminal complement complex, C5b9 in psoriatic skin. When applied on human skin explants, fluorescence from covalently labeled fluorescent MSC exosomes permeated and persisted in the stratum corneum for about 24 hours with negligible exit out of the stratum corneum into the underlying epidermis. As psoriatic stratum corneums are uniquely characterized by activated complements and Munro microabscesses, we postulated that topically applied exosomes permeate the psoriatic stratum corneum to inhibit C5b9 complement complex through CD59, and this inhibition attenuated neutrophil secretion of IL-17. Consistent with this, we demonstrated that assembly of C5b9 on purified human neutrophils induced IL-17 secretion and this induction was abrogated by MSC exosomes, which was in turn abrogated by a neutralizing anti-CD 59 antibody. We thus established the mechanism of action for the alleviation of psoriatic IL-17 by topically applied exosomes.

Therapeutic potentials of mesenchymal stromal cells-derived extracellular vesicles in liver failure and marginal liver graft rehabilitation: a scoping review

Liver failure includes distinct subgroups of diseases: Acute liver failure (ALF) without preexisting cirrhosis, acute-on-chronic liver failure (ACLF) (severe form of cirrhosis associated with organ failures and excess mortality), and liver fibrosis (LF). Inflammation plays a key role in ALF, LF, and more specifically in ACLF for which we have currently no treatment other than liver transplantation (LT). The increasing incidence of marginal liver grafts and the shortage of liver grafts require us to consider strategies to increase the quantity and quality of available liver grafts. Mesenchymal stromal cells (MSCs) have shown beneficial pleiotropic properties with limited translational potential due to the pitfalls associated with their cellular nature. MSC-derived extracellular vesicles (MSC-EVs) are innovative cell-free therapeutics for immunomodulation and regenerative purposes. MSC-EVs encompass further advantages: pleiotropic effects, low immunogenicity, storage stability, good safety profile, and possibility of bioengineering. Currently, no human studies explored the impact of MSC-EVs on liver disease, but several preclinical studies highlighted their beneficial effects. In ALF and ACLF, data showed that MSC-EVs attenuate hepatic stellate cells activation, exert antioxidant, anti-inflammatory, anti-apoptosis, anti-ferroptosis properties, and promote regeneration of the liver, autophagy, and improve metabolism through mitochondrial function recovery. In LF, MSC-EVs demonstrated anti-fibrotic properties associated with liver tissue regeneration. Normothermic-machine perfusion (NMP) combined with MSC-EVs represents an attractive therapy to improve liver regeneration before LT. Our review suggests a growing interest in MSC-EVs in liver failure and gives an appealing insight into their development to rehabilitate marginal liver grafts through NMP.

Stem cell-derived exosomal MicroRNAs: Potential therapies in diabetic kidney disease

The diabetic kidney disease (DKD) is chronic kidney disease caused by diabetes and one of the most common comorbidities. It is often more difficult to treat end-stage renal disease once it develops because of its complex metabolic disorders, so early prevention and treatment are important. However, currently available DKD therapies are not ideal, and novel therapeutic strategies are urgently needed. The potential of stem cell therapies partly depends on their ability to secrete exosomes. More and more studies have shown that stem cell-derived exosomes take part in the DKD pathophysiological process, which may offer an effective therapy for DKD treatment. Herein, we mainly review potential therapies of stem cell-derived exosomes mainly stem cell-derived exosomal microRNAs in DKD, including their protective effects on mesangial cells, podocytes and renal tubular epithelial cells. Using this secretome as possible therapeutic drugs without potential carcinogenicity should be the focus of further research.

Mesenchymal stem cell-derived exosomes in cardiovascular and cerebrovascular diseases: From mechanisms to therapy

Cardiovascular and cerebrovascular diseases (CVDs) remain an intractable problem and have high morbidity and mortality worldwide, as well as substantial health and economic burdens, representing an urgent clinical need. In recent years, the focus of research has shifted from the use of mesenchymal stem cells (MSCs) for transplantation to the use of their secretory exosomes (MSC-exosomes) for the treatment of numerous CVDs, including atherosclerosis, myocardial infarction (MI), heart failure (HF), ischemia/reperfusion (I/R), aneurysm, and stroke. MSCs are pluripotent stem cells with multiple differentiation pathways that exert pleiotropic effects by producing soluble factors, the most effective components of which are exosomes. MSC-exosomes are considered to be an excellent and promising cell-free therapy for CVDs due to their higher circulating stability, improved biocompatibility, reduced toxicity, and immunogenicity. In addition, exosomes play critical roles in repairing CVDs by inhibiting apoptosis, regulating inflammation, ameliorating cardiac remodeling, and promoting angiogenesis. Herein, we describe knowledge about the biological characteristics of MSC-exosomes, investigate the mechanism by which MSC-exosomes mediate therapeutic repair, and summarize recent advances in the efficacy of MSC-exosomes in CVDs, with a view toward future clinical applications.

Exosomes in Cardiovascular Disease: From Mechanism to Therapeutic Target

Cardiovascular disease (CVD) is the leading cause of morbidity and mortality globally. In recent decades, clinical research has made significant advances, resulting in improved survival and recovery rates for patients with CVD. Despite this progress, there is substantial residual CVD risk and an unmet need for better treatment. The complex and multifaceted pathophysiological mechanisms underlying the development of CVD pose a challenge for researchers seeking effective therapeutic interventions. Consequently, exosomes have emerged as a new focus for CVD research because their role as intercellular communicators gives them the potential to act as noninvasive diagnostic biomarkers and therapeutic nanocarriers. In the heart and vasculature, cell types such as cardiomyocytes, endothelial cells, vascular smooth muscle, cardiac fibroblasts, inflammatory cells, and resident stem cells are involved in cardiac homeostasis via the release of exosomes. Exosomes encapsulate cell-type specific miRNAs, and this miRNA content fluctuates in response to the pathophysiological setting of the heart, indicating that the pathways affected by these differentially expressed miRNAs may be targets for new treatments. This review discusses a number of miRNAs and the evidence that supports their clinical relevance in CVD. The latest technologies in applying exosomal vesicles as cargo delivery vehicles for gene therapy, tissue regeneration, and cell repair are described.

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

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

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

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

Reduced graphene oxide-embedded nerve conduits loaded with bone marrow mesenchymal stem cell-derived extracellular vesicles promote peripheral nerve regeneration

We previously combined reduced graphene oxide (rGO) with gelatin-methacryloyl (GelMA) and polycaprolactone (PCL) to create an rGO-GelMA-PCL nerve conduit and found that the conductivity and biocompatibility were improved. However, the rGO-GelMA-PCL nerve conduits differed greatly from autologous nerve transplants in their ability to promote the regeneration of injured peripheral nerves and axonal sprouting. Extracellular vesicles derived from bone marrow mesenchymal stem cells (BMSCs) can be loaded into rGO-GelMA-PCL nerve conduits for repair of rat sciatic nerve injury because they can promote angiogenesis at the injured site. In this study, 12 weeks after surgery, sciatic nerve function was measured by electrophysiology and sciatic nerve function index, and myelin sheath and axon regeneration were observed by electron microscopy, immunohistochemistry, and immunofluorescence. The regeneration of microvessel was observed by immunofluorescence. Our results showed that rGO-GelMA-PCL nerve conduits loaded with BMSC-derived extracellular vesicles were superior to rGO-GelMA-PCL conduits alone in their ability to increase the number of newly formed vessels and axonal sprouts at the injury site as well as the recovery of neurological function. These findings indicate that rGO-GelMA-PCL nerve conduits loaded with BMSC-derived extracellular vesicles can promote peripheral nerve regeneration and neurological function recovery, and provide a new direction for the curation of peripheral nerve defect in the clinic.

Hybrid exosomes, exosome-like nanovesicles and engineered exosomes for therapeutic applications

Exosomes are endosome-derived nanovesicles involved in cellular communication. They are natural nanocarriers secreted by various cells, making them suitable candidates for diverse drug delivery and therapeutic applications from a material standpoint. They have a phospholipid bilayer decorated with functional molecules and an enclosed parental matrix, which has attracted interest in developing designer/hybrid engineered exosome nanocarriers. The structural versatility of exosomes allows the modification of their original configuration using various methods, including genetic engineering, chemical procedures, physical techniques, and microfluidic technology, to load exosomes with additional cargo for expanded biomedical applications. Exosomes show enormous potential for overcoming the limitations of conventional nanoparticle-based techniques in targeted therapy. This review highlights the exosome sources, characteristics, state of the art in the field of hybrid exosomes, exosome-like nanovesicles and engineered exosomes as potential cargo delivery vehicles for therapeutic applications.

A review on exosomes application in clinical trials: perspective, questions, and challenges

BACKGROUND

Exosomes are progressively known as significant mediators of cell-to-cell communication. They convey active biomolecules to target cells and have vital functions in several physiological and pathological processes, and show substantial promise as novel treatment strategies for diseases.

METHODS

In this review study, we studied numerous articles over the past two decades published on application of exosomes in different diseases as well as on perspective and challenges in this field.

RESULTS

The main clinical application of exosomes are using them as a biomarker, cell-free therapeutic agents, drug delivery carriers, basic analysis for exosome kinetics, and cancer vaccine. Different exosomes from human or plant sources are utilized in various clinical trials. Most researchers used exosomes from the circulatory system for biomarker experiments. Mesenchymal stem cells (MSCs) and dendritic cells (DCs) are two widely held cell sources for exosome use. MSCs-derived exosomes are commonly used for inflammation treatment and drug delivery, while DCs-exosomes are used to induce inflammation response in cancer patients. However, the clinical application of exosomes faces various questions and challenges. In addition, translation of exosome-based clinical trials is required to conform to specific good manufacturing practices (GMP). In this review, we summarize exosomes in the clinical trials according to the type of application and disease. We also address the main questions and challenges regarding exosome kinetics and clinical applications.

CONCLUSIONS

Exosomes are promising platforms for treatment of many diseases in clinical trials. This exciting field is developing hastily, understanding of the underlying mechanisms that direct the various observed roles of exosomes remains far from complete and needs further multidisciplinary research in working with these small vesicles. Video Abstract.

Donors for nerve transplantation in craniofacial soft tissue injuries

Neural tissue is an important soft tissue; for instance, craniofacial nerves govern several aspects of human behavior, including the expression of speech, emotion transmission, sensation, and motor function. Therefore, nerve repair to promote functional recovery after craniofacial soft tissue injuries is indispensable. However, the repair and regeneration of craniofacial nerves are challenging due to their intricate anatomical and physiological characteristics. Currently, nerve transplantation is an irreplaceable treatment for segmental nerve defects. With the development of emerging technologies, transplantation donors have become more diverse. The present article reviews the traditional and emerging alternative materials aimed at advancing cutting-edge research on craniofacial nerve repair and facilitating the transition from the laboratory to the clinic. It also provides a reference for donor selection for nerve repair after clinical craniofacial soft tissue injuries. We found that autografts are still widely accepted as the first options for segmental nerve defects. However, allogeneic composite functional units have a strong advantage for nerve transplantation for nerve defects accompanied by several tissue damages or loss. As an alternative to autografts, decellularized tissue has attracted increasing attention because of its low immunogenicity. Nerve conduits have been developed from traditional autologous tissue to composite conduits based on various synthetic materials, with developments in tissue engineering technology. Nerve conduits have great potential to replace traditional donors because their structures are more consistent with the physiological microenvironment and show self-regulation performance with improvements in 3D technology. New materials, such as hydrogels and nanomaterials, have attracted increasing attention in the biomedical field. Their biocompatibility and stimuli-responsiveness have been gradually explored by researchers in the regeneration and regulation of neural networks.

Acellular nerve grafts supplemented with induced pluripotent stem cell-derived exosomes promote peripheral nerve reconstruction and motor function recovery

Peripheral nerve injury is a great challenge in clinical work due to the restricted repair gap and weak regrowth ability. Herein, we selected induced pluripotent stem cells (iPSCs) derived exosomes to supplement acellular nerve grafts (ANGs) with the aim of restoring long-distance peripheral nerve defects. Human fibroblasts were reprogrammed into iPSCs through non-integrating transduction of Oct3/4, Sox2, Klf4, and c-Myc. The obtained iPSCs had highly active alkaline phosphatase expression and expressed Oct4, SSEA4, Nanog, Sox2, which also differentiated into all three germ layers in vivo and differentiated into mature peripheral neurons and Schwann cells (SCs) in vitro. After isolation and biological characteristics of iPSCs-derived exosomes, we found that numerous PKH26-labeled exosomes were internalized inside SCs through endocytotic pathway and exhibited a proliferative effect on SCs that were involved in the process of axonal regeneration and remyelination. After that, we prepared ANGs via optimized chemical extracted process to bridge 15 mm long-distance peripheral nerve gaps in rats. Owing to the promotion of iPSCs-derived exosomes, satisfactory regenerative outcomes were achieved including gait behavior analysis, electrophysiological assessment, and morphological analysis of regenerated nerves. Especially, motor function was restored with comparable to those achieved with nerve autografts and there were no significant differences in the fiber diameter and area of reinnervated muscle fibers. Taken together, our combined use of iPSCs-derived exosomes with ANGs demonstrates good promise to restore long-distance peripheral nerve defects, and thus represents a cell-free strategy for future clinical applications.

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IPSCs-derived exosomes provide a novel cell-free strategy with the regenerative power of iPSCs.

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ANGs supplemented with iPSCs-derived exosomes show enhanced peripheral repair and accelerated motor functional recovery.

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IPSCs-derived exosomes provide equivalent histological morphology to autologous nerve transplantation.

Safety and biodistribution of exosomes derived from human induced pluripotent stem cells

As a new cell-free therapy, exosomes have provided new ideas for the treatment of various diseases. Human induced pluripotent stem cells (hiPSCs) cannot be used in clinical trials because of tumorigenicity, but the exosomes derived from hiPSCs may combine the advantages of iPSC pluripotency and the nanoscale size of exosomes while avoiding tumorigenicity. Currently, the safety and biodistribution of hiPSC-exosomes in vivo are unclear. Here, we investigated the effects of hiPSC-exosomes on hemolysis, DNA damage, and cytotoxicity through cell experiments. We also explored the safety of vein injection of hiPSC-exosomes in rabbits and rats. Differences in organ distribution after nasal administration were compared in normal and Parkinson’s disease model mice. This study may provide support for clinical therapy and research of intravenous and nasal administration of hiPSC-exosomes.

Investigations on Cellular Uptake Mechanisms and Immunogenicity Profile of Novel Bio-Hybrid Nanovesicles

In drug delivery, the development of nanovesicles that combine both synthetic and cellular components provides added biocompatibility and targeting specificity in comparison to conventional synthetic carriers such as liposomes. Produced through the fusion of U937 monocytes' membranes and synthetic lipids, our nano-cell vesicle technology systems (nCVTs) showed promising results as targeted cancer treatment. However, no investigation has been conducted yet on the immunogenic profile and the uptake mechanisms of nCVTs. Hence, this study was aimed at exploring the potential cytotoxicity and immune cells' activation by nCVTs, as well as the routes through which cells internalize these biohybrid systems. The endocytic pathways were selectively inhibited to establish if the presence of cellular components in nCVTs affected the internalization route in comparison to both liposomes (made up of synthetic lipids only) and nano-cellular membranes (made up of biological material only). As a result, nCVTs showed an 8-to-40-fold higher cellular internalization than liposomes within the first hour, mainly through receptor-mediated processes (i.e., clathrin- and caveolae-mediated endocytosis), and low immunostimulatory potential (as indicated by the level of IL-1α, IL-6, and TNF-α cytokines) both in vitro and in vivo. These data confirmed that nCVTs preserved surface cues from their parent U937 cells and can be rationally engineered to incorporate ligands that enhance the selective uptake and delivery toward target cells and tissues.

Innovative Treatment Strategies to Accelerate Wound Healing: Trajectory and Recent Advancements

Wound healing is highly specialized dynamic multiple phase process for the repair of damaged/injured tissues through an intricate mechanism. Any failure in the normal wound healing process results in abnormal scar formation, and chronic state which is more susceptible to infections. Chronic wounds affect patients’ quality of life along with increased morbidity and mortality and are huge financial burden to healthcare systems worldwide, and thus requires specialized biomedical intensive treatment for its management. The clinical assessment and management of chronic wounds remains challenging despite the development of various therapeutic regimens owing to its painstakingly long-term treatment requirement and complex wound healing mechanism. Various conventional approaches such as cell therapy, gene therapy, growth factor delivery, wound dressings, and skin grafts etc., are being utilized for promoting wound healing in different types of wounds. However, all these abovementioned therapies are not satisfactory for all wound types, therefore, there is an urgent demand for the development of competitive therapies. Therefore, there is a pertinent requirement to develop newer and innovative treatment modalities for multipart therapeutic regimens for chronic wounds. Recent developments in advanced wound care technology includes nanotherapeutics, stem cells therapy, bioengineered skin grafts, and 3D bioprinting-based strategies for improving therapeutic outcomes with a focus on skin regeneration with minimal side effects. The main objective of this review is to provide an updated overview of progress in therapeutic options in chronic wounds healing and management over the years using next generation innovative approaches. Herein, we have discussed the skin function and anatomy, wounds and wound healing processes, followed by conventional treatment modalities for wound healing and skin regeneration. Furthermore, various emerging and innovative strategies for promoting quality wound healing such as nanotherapeutics, stem cells therapy, 3D bioprinted skin, extracellular matrix-based approaches, platelet-rich plasma-based approaches, and cold plasma treatment therapy have been discussed with their benefits and shortcomings. Finally, challenges of these innovative strategies are reviewed with a note on future prospects.

New Approaches for Enhancement of the Efficacy of Mesenchymal Stem Cell-Derived Exosomes in Cardiovascular Diseases

Cardiovascular diseases (CVDs) remain a major health concern worldwide, where mesenchymal stem cells (MSCs) therapy gives great promise in their management through their regenerative and paracrine actions. In recent years, many studies have shifted from the use of transplanted stem cells to their secreted exosomes for the management of various CVDs and cardiovascular-related diseases including atherosclerosis, stroke, myocardial infarction, heart failure, peripheral arterial diseases, and pulmonary hypertension. In different models, MSC-derived exosomes have shown beneficial outcomes similar to cell therapy concerning regenerative and neovascular actions in addition to their anti-apoptotic, anti-remodeling, and anti-inflammatory actions. Compared with their parent cells, exosomes have also demonstrated several advantages, including lower immunogenicity and no risk of tumor formation. However, the maintenance of stability and efficacy of exosomes after in vivo transplantation is still a major concern in their clinical application. Recently, new approaches have been developed to enhance their efficacy and stability including their preconditioning before transplantation, use of genetically modified MSC-derived exosomes, or their utilization as a targeted drug delivery system. Herein, we summarized the use of MSC-derived exosomes as therapies in different CVDs in addition to recent advances for the enhancement of their efficacy in these conditions.

Comprehensive proteomic analysis of exosome mimetic vesicles and exosomes derived from human umbilical cord mesenchymal stem cells

BACKGROUND

Exosomes derived from mesenchymal stem cells (MSCs) have shown to have effective application prospects in the medical field, but exosome yield is very low. The production of exosome mimetic vesicles (EMVs) by continuous cell extrusion leads to more EMVs than exosomes, but whether the protein compositions of MSC-derived EMVs (MSC-EMVs) and exosomes (MSC-exosomes) are substantially different remains unknown. The purpose of this study was to conduct a comprehensive proteomic analysis of MSC-EMVs and MSC-exosomes and to simply explore the effects of exosomes and EMVs on wound healing ability. This study provides a theoretical basis for the application of EMVs and exosomes.

METHODS

In this study, EMVs from human umbilical cord MSCs (hUC MSCs) were isolated by continuous extrusion, and exosomes were identified after hUC MSC ultracentrifugation. A proteomic analysis was performed, and 2315 proteins were identified. The effects of EMVs and exosomes on the proliferation, migration and angiogenesis of human umbilical vein endothelial cells (HUVECs) were evaluated by cell counting kit-8, scratch wound, transwell and tubule formation assays. A mouse mode was used to evaluate the effects of EMVs and exosomes on wound healing.

RESULTS

Bioinformatics analyses revealed that 1669 proteins in both hUC MSC-EMVs and hUC MSC-exosomes play roles in retrograde vesicle-mediated transport and vesicle budding from the membrane. The 382 proteins unique to exosomes participate in extracellular matrix organization and extracellular structural organization, and the 264 proteins unique to EMVs target the cell membrane. EMVs and exosomes can promote wound healing and angiogenesis in mice and promote the proliferation, migration and angiogenesis of HUVECs.

CONCLUSIONS

This study presents a comprehensive proteomic analysis of hUC MSC-derived exosomes and EMVs generated by different methods. The tissue repair function of EMVs and exosomes was herein verified by wound healing experiments, and these results reveal their potential applications in different fields based on analyses of their shared and unique proteins.

Biological Features of Extracellular Vesicles and Challenges

Extracellular vesicles (EVs) are vesicles with a lipid bilayer membrane on the outside, which are widely found in various body fluids and contain biological macromolecules such as DNA, RNA, lipids and proteins on the inside. EVs were once thought to be vesicles for the removal of waste materials, but are now known to be involved in a variety of pathophysiological processes in many diseases. This study examines the advantage of EVs and the challenges associated with their application. A more rational use of the advantageous properties of EVs such as composition specificity, specific targeting, circulatory stability, active penetration of biological barriers, high efficient drug delivery vehicles and anticancer vaccines, oxidative phosphorylation activity and enzymatic activity, and the resolution of shortcomings such as isolation and purification methods, storage conditions and pharmacokinetics and biodistribution patterns during drug delivery will facilitate the clinical application of EVs.

Exosomes from LPS-preconditioned bone marrow MSCs accelerated peripheral nerve regeneration via M2 macrophage polarization: Involvement of TSG-6/NF-κB/NLRP3 signaling pathway

Lipopolysaccharide (LPS)-preconditioned mesenchymal stem cells (MSCs) possessed strong immunomodulatory and anti-inflammatory functions by secreting exosomes as major paracrine effectors. However, the specific effect of exosomes from LPS pre-MSCs (LPS pre-Exos) on peripheral nerve regeneration has yet to be documented. Here, we established a sciatic nerve injury model in rats and an inflammatory model in RAW264.7 cells to explore the potential mechanism between LPS pre-Exos and peripheral nerve repair. The local injection of LPS pre-Exos into the nerve injury site resulted in an accelerated functional recovery, axon regeneration and remyelination, and an enhanced M2 Macrophage polarization. Consistent with the data in vivo, LPS pre-Exos were able to shift the pro-inflammation macrophage into a pro-regeneration macrophage. Notably, TNF stimulated gene-6 (TSG-6) was found to be highly enriched in LPS pre-Exos. We obtained si TSG-6 Exo by the knockdown of TSG-6 in LPS pre-Exos to demonstrate the role of TSG-6 in macrophage polarization, and found that TSG-6 served as a critical mediator in LPS pre-Exos-induced regulatory effects through the inhibition of NF-ΚΒ and NOD-like receptor protein 3 (NLRP3). In conclusion, our findings suggested that LPS pre-Exos promoted macrophage polarization toward an M2 phenotype by shuttling TSG-6 to inactivate the NF-ΚΒ/NLRP3 signaling axis, and could provide a potential therapeutic avenue for peripheral nerve repair.

Applications of Extracellular Vesicles in Abdominal Aortic Aneurysm

Abdominal aortic aneurysm (AAA) is a localized expansion of the abdominal aorta which can lead to lethal complication as the rupture of aortic wall. Currently there is still neither competent method to predict the impending rupture of aneurysm, nor effective treatment to arrest the progression of small and asymptomatic aneurysms. Accumulating evidence has confirmed the crucial role of extracellular vesicles (EVs) in the pathological course of AAA, acting as important mediators of intercellular communication. Given the advantages of intrinsic targeting properties, lower toxicity and fair stability, EVs show great potential to serve as biomarkers, therapeutic agents and drug delivery carriers. However, EV therapies still face several major challenges before they can be applied clinically, including off-target effect, low accumulation rate and rapid clearance by mononuclear phagocyte system. In this review, we first illustrate the roles of EV in the pathological process of AAA and evaluate its possible clinical applications. We also identify present challenges for EV applications, highlight different strategies of EV engineering and constructions of EV-like nanoparticles, including EV display technology and membrane hybrid technology. These leading-edge techniques have been recently employed in multiple cardiovascular diseases and their promising application in the field of AAA is discussed.

Characteristics of Extracellular Vesicles and Preclinical Testing Considerations Prior to Clinical Applications

Cell therapy products have significant limitations, such as storage instability, difficulties with transportation, and toxicity issues such as tumorigenicity and immunogenicity. Extracellular vesicles (EVs) secreted from cells show potential for therapeutic agent development. EVs have not been widely examined as investigational drugs, and non-clinical studies for the clinical approval of EV therapeutic agents are challenging. EVs contain various materials, such as DNA, cellular RNA, cytokines, chemokines, and microRNAs, but do not proliferate or divide like cells, thus avoiding safety concerns related to tumorigenicity. However, the constituents of EVs may induce the proliferation of normal cells; therefore, the suitability of vesicles should be verified through non-clinical safety evaluations. In this review, the findings of non-clinical studies on EVs are summarized. We describe non-clinical toxicity studies of EVs, which should be useful for researchers who aim to develop these vesicles into therapeutic agents. A new method for evaluating the immunotoxicity and tumorigenicity of EVs should also be developed.

Bone Cell Exosomes and Emerging Strategies in Bone Engineering

Bone tissue remodeling is a highly regulated process balancing bone formation and resorption through complex cellular crosstalk between resident bone and microenvironment cells. This cellular communication is mediated by direct cell and cell–matrix contact, autocrine, endocrine, and paracrine receptor mediated mechanisms such as local soluble signaling molecules and extracellular vesicles including nanometer sized exosomes. An impairment in this balanced process leads to development of pathological conditions. Bone tissue engineering is an emerging interdisciplinary field with potential to address bone defects and disorders by synthesizing three-dimensional bone substitutes embedded with cells for clinical implantation. However, current cell-based therapeutic approaches have faced hurdles due to safety and ethical concerns, challenging their clinical translation. Recent studies on exosome-regulated bone homeostasis and regeneration have gained interest as prospective cell free therapy in conjugation with tissue engineered bone grafts. However, exosome research is still in its nascent stages of bone tissue engineering. In this review, we specifically describe the role of exosomes secreted by cells within bone microenvironment such as osteoblasts, osteocytes, osteoclasts, mesenchymal stem cell cells, immune cells, endothelial cells, and even tumor cells during bone homeostasis and crosstalk. We also review exosome-based osteoinductive functionalization strategies for various bone-based biomaterials such as ceramics, polymers, and metals in bone tissue engineering. We further highlight biomaterials as carrier agents for exosome delivery to bone defect sites and, finally, the influence of various biomaterials in modulation of cell exosome secretome.

LncRNA SNHG11 enhances bevacizumab resistance in colorectal cancer by mediating miR-1207-5p/ABCC1 axis

Long noncoding RNAs (lncRNAs) have been reported to serve as vital regulators in the chemoresistance of human cancers, including colorectal cancer (CRC). In this study, we aimed to explore the functions of lncRNA small nucleolar RNA host gene 11 (SNHG11) in the resistance of CRC to bevacizumab. Quantitative real-time PCR, western blot assay or immunohistochemistry assay were performed to examine the expression of SNHG11, microRNA-1207-5p (miR-1207-5p), ATP binding cassette subfamily C member 1 (ABCC1) and Ki67. Cell Counting Kit-8 assay was conducted to evaluate bevacizumab resistance and cell viability. 5'-ethynyl-2'-deoxyuridine analysis, flow cytometry analysis and wound-healing assay were conducted for cell proliferation, apoptosis and migration, respectively. Dual-luciferase reporter assay and RNA immunoprecipitation assay were employed to analyze the relations among SNHG11, miR-1207-5p and ABCC1. Murine xenograft model assay was employed to analyze bevacizumab resistance in vivo. The exosomes were observed under transmission electron microscopy. SNHG11 was overexpressed in bevacizumab-resistant CRC tissues and cells. Knockdown of SNHG11 restrained bevacizumab resistance, repressed cell proliferation and migration, and promoted apoptosis in bevacizumab-resistant CRC cells. MiR-1207-5p served as the target of SNHG11 and SNHG11 regulated bevacizumab resistance by targeting miR-1207-5p. ABCC1 was the target gene of miR-1207-5p. Overexpression of miR-1207-5p inhibited bevacizumab resistance and cell progression in bevacizumab-resistant CRC cells, with ABCC1 elevation abrogated the impacts. SNHG11 silencing repressed bevacizumab resistance in vivo. In addition, exosomal SNHG11 was upregulated in bevacizumab-resistant CRC cells. SNHG11 contributes to bevacizumab resistance in CRC depending on the modulation of miR-1207-5p and ABCC1.

Update on the role of extracellular vesicles in rheumatoid arthritis

Rheumatoid arthritis (RA) is a heterogeneous autoimmune disorder that leads to severe joint deformities, negatively affecting the patient's quality of life. Extracellular vesicles (EVs), which include exosomes and ectosomes, act as intercellular communication mediators in several physiological and pathological processes in various diseases including RA. In contrast, EVs secreted by mesenchymal stem cells perform an immunomodulatory function and stimulate cartilage repair, showing promising therapeutic results in animal models of RA. EVs from other sources, including dendritic cells, neutrophils and myeloid-derived suppressor cells, also influence the biological function of immune and joint cells. This review describes the role of EVs in the pathogenesis of RA and presents evidence supporting future studies on the therapeutic potential of EVs from different sources. This information will contribute to a better understanding of RA development, as well as a starting point for exploring cell-free-based therapies for RA.

New Perspectives to Improve Mesenchymal Stem Cell Therapies for Drug-Induced Liver Injury

Drug-induced liver injury (DILI) is one of the leading causes of acute liver injury. Many factors may contribute to the susceptibility of patients to this condition, making DILI a global medical problem that has an impact on public health and the pharmaceutical industry. The use of mesenchymal stem cells (MSCs) has been at the forefront of regenerative medicine therapies for many years, including MSCs for the treatment of liver diseases. However, there is currently a huge gap between these experimental approaches and their application in clinical practice. In this concise review, we focus on the pathophysiology of DILI and highlight new experimental approaches conceived to improve cell-based therapy by the in vitro preconditioning of MSCs and/or the use of cell-free products as treatment for this liver condition. Finally, we discuss the advantages of new approaches, but also the current challenges that must be addressed in order to develop safer and more effective procedures that will allow cell-based therapies to reach clinical practice, enhancing the quality of life and prolonging the survival time of patients with DILI.