To Protect and to Preserve: Novel Preservation Strategies for Extracellular Vesicles

Development of human amniotic epithelial cell-derived extracellular vesicles as cell-free therapy for dry eye disease

PURPOSE

This study aimed to investigate the therapeutic potential of extracellular vesicles (EVs) derived from human amniotic epithelial cells (hAEC-EVs) for Dry Eye Disease (DED) treatment.

METHODS

Highly purified EVs were isolated from the culture supernatants of hAECs, which obtained from term placenta and characterized. Proteomic contents were analyzed for assessing its biological function related to the therapeutic potentials for DED. Subsequently, we examined the therapeutic efficacy of hAEC-EVs on human corneal epithelial cells exposed to hyperosmotic stress and in an experimental DED mouse model induced by desiccation stress.

RESULTS

Proteomic analysis of hAEC-EVs revealed proteins linked to cell proliferation and anti-inflammatory responses. We demonstrated efficient uptake of hAEC-EVs by ocular surface cells. Under DED conditions, EV treatment increased corneal epithelial cell proliferation and migration, and concurrently reducing inflammatory cytokines. In the DED mouse model, hAEC-EVs showed significant improvements in corneal staining score, tear secretion, corneal irregularity, and conjunctival goblet cell density. Additionally, hAEC-EVs exhibited a mitigating effect on ocular surface inflammation induced by desiccation.

CONCLUSIONS

These findings suggest that hAEC-EVs hold potential as a cell-free therapy for corneal epithelial defects and ocular surface diseases, presenting a promising treatment option for DED.

Exosomal therapy is a luxury area for regenerative medicine

Stem cell-based therapies have made significant advancements in tissue regeneration and medical engineering. However, there are limitations to cell transplantation therapy, such as immune rejection and limited cell viability. These limitations greatly impede the translation of stem cell-based tissue regeneration into clinical practice. In recent years, exosomes, which are packaged vesicles released from cells, have shown promising progress. Specifically, exosomes derived from stem cells have demonstrated remarkable therapeutic benefits. Exosomes are nanoscale extracellular vesicles that act as paracrine mediators. They transfer functional cargos, such as miRNA and mRNA molecules, peptides, proteins, cytokines, and lipids, from MSCs to recipient cells. By participating in intercellular communication events, exosomes contribute to the healing of injured or diseased tissues and organs. Studies have shown that the therapeutic effects of MSCs in various experimental paradigms can be solely attributed to their exosomes. Consequently, MSC-derived exosomes can be modified and utilized to develop a unique cell-free therapeutic approach for treating multiple diseases, including neurological, immunological, heart, and other diseases. This review is divided into several categories, including the current understanding of exosome biogenesis, isolation techniques, and their application as therapeutic tools.

Effect of lyophilized exosomes derived from umbilical cord stem cells on chronic anterior cruciate ligament cell injury

BACKGROUND

Facilitating the healing process of injured anterior cruciate ligament (ACL) tissue is crucial for patients to safely return to sports. Stem cell derived exosomes have shown positive effects on enhancing the regeneration of injured tendons/ligaments. However, clinical application of exosomes in terms of storage and pre-assembly is challenging. We hypothesized that lyophilized exosomes derived from human umbilical cord stem cells (hUSC-EX) could enhance the cell activity of chronically injured ACL cells.

MATERIALS AND METHODS

We harvested the 8 weeks injured ACL cells from rabbit under IACUC (No. 110232) approval. The studied exosomes were purified from the culture medium of human umbilical cord stem cells (IRB approval No. A202205014), lyophilized to store, and hydrated for use. We compared exosome treated cells with non-exosome treated cells (control group) from the same rabbits. We examined the cell viability, proliferation, migration capability and gene expression of type I and III collagen, TGFβ, VEGF, and tenogenesis in the 8 weeks injured ACL cells after hUSC-EX treatment.

RESULTS

After hydration, the average size of hUSC-EX was 84.5 ± 70.6 nm, and the cells tested positive for the Alix, TSG101, CD9, CD63, and CD81 proteins but negative for the α-Tubulin protein. After 24 h of treatment, hUSC-EX significantly improved the cell viability, proliferation and migration capability of 8 weeks injured ACL cells compared to that of no exosome treatment group. In addition, the expression of collagen synthesis, TGFβ, VEGF, and tenogenesis gene were all significantly increased in the 8 weeks injured ACL cells after 24 h hUSC-EX delivery.

DISCUSSION

Lyophilized exosomes are easily stored and readily usable after hydration, thereby preserving their characteristic properties. Treatment with lyophilized hUSC-EX improved the activity and gene expression of 8 weeks injured ACL cells.

CONCLUSION

Lyophilized hUSC-EX preserve the characteristics of exosomes and can improve chronically injured (8 weeks) ACL cells. Lyophilized hUSC-EX could serve as effective and safe biomaterials that are ready to use at room temperature to enhance cell activity in patients with partial ACL tears and after remnant preservation ACL reconstruction.

Scalable Purification, Storage, and Release of Plant-Derived Nanovesicles for Local Therapy Using Nanostructured All-Cellulose Composite Membranes

Plant-derived nanovesicles such as bilberries nanovesicles (BNVs) show immense promise as next-generation biotherapeutics and functional food ingredients; however, their isolation, purification, and storage on a large scale remain a challenge. In this study, biocompatible and nanostructured composite all-cellulose membranes are introduced as a scalable and straightforward approach to the isolation of BNV. The membranes consisting of a cellulose acetate matrix infused with anionic or cationic nanocelluloses promoted selective capture of BNVs through electrostatic and size-exclusion-mediated depth filtration. Furthermore, the surface of the composite membrane acted as a storage matrix for BNVs, ensuring their prolonged stability at 4 °C. The BNVs stored in the membrane could be promptly released through elution assisted by low-pressure vacuum filtration or diffusion in liquid media. The morphology, bioactivity, and stability of the extracted BNVs were preserved, and the release rate of BNVs in different cell cultures could be regulated, facilitating their use for local therapy. Consequently, this approach paves the way for the scalable production, purification, and storage of nanovesicles and advances their use in biotherapeutics and functional foods.

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.

Charge-Reversed Exosomes for Targeted Gene Delivery to Cartilage for Osteoarthritis Treatment

Gene therapy has the potential to facilitate targeted expression of therapeutic proteins to promote cartilage regeneration in osteoarthritis (OA). The dense, avascular, aggrecan-glycosaminoglycan (GAG) rich negatively charged cartilage, however, hinders their transport to reach chondrocytes in effective doses. While viral vector mediated gene delivery has shown promise, concerns over immunogenicity and tumorigenic side-effects persist. To address these issues, this study develops surface-modified cartilage-targeting exosomes as non-viral carriers for gene therapy. Charge-reversed cationic exosomes are engineered for mRNA delivery by anchoring cartilage targeting optimally charged arginine-rich cationic motifs into the anionic exosome bilayer by using buffer pH as a charge-reversal switch. Cationic exosomes penetrated through the full-thickness of early-stage arthritic human cartilage owing to weak-reversible ionic binding with GAGs and efficiently delivered the encapsulated eGFP mRNA to chondrocytes residing in tissue deep layers, while unmodified anionic exosomes do not. When intra-articularly injected into destabilized medial meniscus mice knees with early-stage OA, mRNA loaded charge-reversed exosomes overcame joint clearance and rapidly penetrated into cartilage, creating an intra-tissue depot and efficiently expressing eGFP; native exosomes remained unsuccessful. Cationic exosomes thus hold strong translational potential as a platform technology for cartilage-targeted non-viral delivery of any relevant mRNA targets for OA treatment.

Signaling pathways activated and regulated by stem cell-derived exosome therapy

Stem cell-derived exosomes exert comparable therapeutic effects to those of their parental stem cells without causing immunogenic, tumorigenic, and ethical disadvantages. Their therapeutic advantages are manifested in the management of a broad spectrum of diseases, and their dosing versatility are exemplified by systemic administration and local delivery. Furthermore, the activation and regulation of various signaling cascades have provided foundation for the claimed curative effects of exosomal therapy. Unlike other relevant reviews focusing on the upstream aspects (e.g., yield, isolation, modification), and downstream aspects (e.g. phenotypic changes, tissue response, cellular behavior) of stem cell-derived exosome therapy, this unique review endeavors to focus on various affected signaling pathways. After meticulous dissection of relevant literature from the past five years, we present this comprehensive, up-to-date, disease-specific, and pathway-oriented review. Exosomes sourced from various types of stem cells can regulate major signaling pathways (e.g., the PTEN/PI3K/Akt/mTOR, NF-κB, TGF-β, HIF-1α, Wnt, MAPK, JAK-STAT, Hippo, and Notch signaling cascades) and minor pathways during the treatment of numerous diseases encountered in orthopedic surgery, neurosurgery, cardiothoracic surgery, plastic surgery, general surgery, and other specialties. We provide a novel perspective in future exosome research through bridging the gap between signaling pathways and surgical indications when designing further preclinical studies and clinical trials.

Therapeutic potential of extracellular vesicles derived from human amniotic epithelial cells for perinatal cerebral and pulmonary injury

Lung and brain injury that occurs during the perinatal period leads to lifelong disability and is often driven and/or exacerbated by inflammation. Human amniotic epithelial cells (hAEC), which demonstrate immunomodulatory, anti-fibrotic, and regenerative capabilities, are being explored as a therapeutic candidate for perinatal injury. However, limitations regarding scalable manufacturing, storage, transport, and dose-related toxicity have impeded clinical translation. Isolated therapeutic extracellular vesicles (EVs) from stem and stem-like cells are thought to be key paracrine mediators of therapeutic efficacy. The unique characteristics of EVs suggest that they potentially circumvent the limitations of traditional cell-based therapies. However, given the novelty of EVs as a therapeutic, recommendations around ideal methods of production, isolation, storage, and delivery have not yet been created by regulatory agencies. In this concise review, we discuss the pertinence and limitations of cell-based therapeutics in perinatal medicine. We also review the preclinical evidence supporting the use of therapeutic EVs for perinatal therapy. Further, we summarize the arising considerations regarding adequate cell source, biodistribution, isolation and storage methods, and regulatory roadblocks for the development of therapeutic EVs.

Size-Exclusion Chromatography: A Path to Higher Yield and Reproducibility Compared to Sucrose Cushion Ultracentrifugation for Extracellular Vesicle Isolation in Multiple Myeloma

Small extracellular vesicles (EVs) play a pivotal role in intercellular communication across various physiological and pathological contexts. Despite their growing significance as disease biomarkers and therapeutic targets in biomedical research, the lack of reliable isolation techniques remains challenging. This study characterizes vesicles that were isolated from conditioned culture media (CCM) sourced from three myeloma cell lines (MM.1S, ANBL-6, and ALMC-1), and from the plasma of healthy donors and multiple myeloma patients. We compared the efficacy, reproducibility, and specificity of isolating small EVs using sucrose cushion ultracentrifugation (sUC) vs. ultrafiltration combined with size-exclusion chromatography (UF-SEC). Our results demonstrate that UF-SEC emerges as a more practical, efficient, and consistent method for EV isolation, outperforming sUC in the yield of EV recovery and exhibiting lower variability. Additionally, the comparison of EV characteristics among the three myeloma cell lines revealed distinct biomarker profiles. Finally, our results suggest that HBS associated with Tween 20 improves EV recovery and preservation over PBS. Standardization of small EV isolation methods is imperative, and our comparative evaluation represents a significant step toward achieving this goal.

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.

From biogenesis to aptasensors: advancements in analysis for tumor-derived extracellular vesicles research

Extracellular vesicles (EVs) are enclosed by a nanoscale phospholipid bilayer membrane and typically range in size from 30 to 200 nm. They contain a high concentration of specific proteins, nucleic acids, and lipids, reflecting but not identical to the composition of the parent cell. The inherent characteristics and variety of EVs give them extensive and unique advantages in the field of cancer identification and treatment. Recently, EVs have been recognized as potential tumor markers for the detection of cancer. Aptamers, which are molecules of single-stranded DNA or RNA, demonstrate remarkable specificity and affinity for their targets by adopting distinct tertiary structures. Aptamers offer various advantages over their protein counterparts, such as reduced immunogenicity, the ability for convenient large-scale synthesis, and straightforward chemical modification. In this review, we summarized EVs biogenesis, sample collection, isolation, storage and characterization, and finally provided a comprehensive survey of analysis techniques for EVs detection that are based on aptamers.

Exosomes in the Real World of Medical Aesthetics: A Review

BACKGROUND

Exosomes are cell-derived nanovesicles that transport proteins, nucleic acids, and lipids and play a significant role in almost every physiological process in the human body. They have generated great interest, especially in the field of tissue regeneration. Studies in the last decade support their great regenerating and rejuvenating potential. However, the lack of standardized procedures, limited knowledge regarding their action mechanism, and little clinical evidence impair their implementation and approval in the medical setting. This review aimed to identify published studies and clinical trials using exosomes in human patients for clinical treatments in aesthetic medicine.

MATERIALS AND METHODS

A systematic search was conducted in the PubMed database using the search term "exosomes" and 25 terms related to aesthetic medicine treatments in human patients. Additionally, a search was conducted in the ClinicalTrials.gov database for interventional clinical trials using exosomes for aesthetic treatments in adults 18 to ≥ 65 years of age.

RESULTS

Nine articles were selected after debugging the initial list of published articles in which exosomes were related to Aesthetic Medicine (633 articles). Nine studies were identified from the initial search on ClinicalTrial.gov (104 trials with exosomes).

CONCLUSIONS

There is no doubt about the scientific basis of exosome regenerative potential and the growing interest in exosomes in Aesthetic Medicine. However, companies must spend more on research to develop standardized and reliable procedures to obtain exosomes for their approval and application in clinical practice.

LEVEL OF EVIDENCE III

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 . This review highlights the large amount of published research on exosomes related to aesthetic medicine and, at the same time, the lack of products approved by regulatory agencies. Several issues have been suggested to elucidate a response, such as the need for standardized protocols and more knowledge to ensure safe treatments. It also highlights the few clinical trials conducted to evaluate exosome properties in aesthetic medicine treatments.

Extracellular vesicle isolation methods identify distinct HIV-1 particles released from chronically infected T-cells

The current study analyzed the intersecting biophysical, biochemical, and functional properties of extracellular particles (EPs) with the human immunodeficiency virus type-1 (HIV-1) beyond the currently accepted size range for HIV-1. We isolated five fractions (Frac-A through Frac-E) from HIV-infected cells by sequential differential ultracentrifugation (DUC). All fractions showed a heterogeneous size distribution with median particle sizes greater than 100 nm for Frac-A through Frac-D but not for Frac-E, which contained small EPs with an average size well below 50 nm. Synchronized and released cultures contained large infectious EPs in Frac-A, with markers of amphisomes and viral components. Additionally, Frac-E uniquely contained EPs positive for CD63, HSP70, and HIV-1 proteins. Despite its small average size, Frac-E contained membrane-protected viral integrase, detectable only after SDS treatment, indicating that it is enclosed in vesicles. Single particle analysis with dSTORM further supported these findings as CD63, HIV-1 integrase, and the viral surface envelope (Env) glycoprotein (gp) colocalized on the same Frac-E particles. Surprisingly, Frac-E EPs were infectious, and infectivity was significantly reduced by immunodepleting Frac-E with anti-CD63, indicating the presence of this protein on the surface of infectious small EPs in Frac-E. To our knowledge, this is the first time that extracellular vesicle (EV) isolation methods have identified infectious small HIV-1 particles (smHIV-1) that are under 50 nm. Collectively, our data indicate that the crossroads between EPs and HIV-1 potentially extend beyond the currently accepted biophysical properties of HIV-1, which may have further implications for viral pathogenesis.

The potential mechanisms and treatment effects of stem cell-derived exosomes in cardiac reengineering

Exosomes are extracellular vesicles of diverse compositions that are secreted by numerous cell types. Exosomes contain significant bioactive components, including lipids, proteins, mRNA, and miRNA. Exosomes play an important role in regulating cellular signaling and trafficking under both normal physiological and pathological circumstances. A multitude of factors, including thermal stress, ribosomal stress, endoplasmic reticulum stress, and oxidative stress influence the concentrations of exosomal mRNA, miRNA, proteins, and lipids. It has been stated that exosomes derived from stem cells (SCs) modulate a range of stresses by preventing or fostering cell balance. Exosomes derived from SCs facilitate recovery by facilitating cross-cellular communication via the transmission of information in the form of proteins, lipids, and other components. For this reason, exosomes are used as biomarkers to diagnose a wide variety of diseases. The focus of this review is the bioengineering of artificial exosomal cargoes. This process encompasses the control and transportation of particular exosomal cargoes, including but not limited to small molecules, recombinant proteins, immune modulators, and therapeutic medications. Therapeutic approaches of this nature have the potential to deliver therapeutic medications precisely to the intended site for the cure of a variety of disorders. Notably, our attention has been directed towards the therapeutic implementations of exosomes derived from SCs in the cure of cardiovascular ailments, including but not limited to ischemic heart disease, myocardial infarction, sepsis, heart failure, cardiomyopathy, and cardiac fibrosis. In general, researchers employ two methodologies when it comes to exosomal bioengineering. This review aims to explain the function of exosomes derived from SCs in the regulation of stress and present a novel therapeutic approach for cardiovascular disorders.

Macromolecules with predominant β-pleated sheet proteins in extracellular vesicles released from Raphanus sativus L. var. caudatus Alef microgreens induce DNA damage-mediated apoptosis in HCT116 colon cancer cells

Plant-derived bioactive macromolecules (i.e., proteins, lipids, and nucleic acids) were prepared as extracellular vesicles (EVs). Plant-derived EVs are gaining pharmaceutical research interest because of their bioactive components and delivery properties. The spherical nanosized EVs derived from Raphanus sativus L. var. caudatus Alef microgreens previously showed antiproliferative activity in HCT116 colon cancer cells from macromolecular compositions (predominantly proteins). To understand the mechanism of action, the biological activity studies, i.e., antiproliferation, cellular biochemical changes, DNA conformational changes, DNA damage, apoptotic nuclear morphological changes, apoptosis induction, and apoptotic pathways, were determined by neutral red uptake assay, synchrotron radiation-based Fourier transform infrared microspectroscopy, circular dichroism spectroscopy, comet assay, 4',6-diamidino-2-phenylindole (DAPI) staining, flow cytometry, and caspase activity assay, respectively. EVs inhibited HCT116 cell growth in concentration- and time-dependent manners, with a half-maximal inhibitory concentration of 675.4 ± 33.8 μg/ml at 48 h and a selectivity index of 1.5 ± 0.076. HCT116 treated with EVs mainly changed the cellular biochemical compositions in the nucleic acids and carbohydrates region. The DNA damage caused no changes in DNA conformation. The apoptotic nuclear morphological changes were associated with the increased apoptotic cell population. The apoptotic cell death was induced by both extrinsic and intrinsic pathways. EVs have potential as antiproliferative bioparticles.

Applications of Stem Cell-Derived Extracellular Vesicles in Nerve Regeneration

Extracellular vesicles (EVs), including exosomes, microvesicles, and other lipid vesicles derived from cells, play a pivotal role in intercellular communication by transferring information between cells. EVs secreted by progenitor and stem cells have been associated with the therapeutic effects observed in cell-based therapies, and they also contribute to tissue regeneration following injury, such as in orthopaedic surgery cases. This review explores the involvement of EVs in nerve regeneration, their potential as drug carriers, and their significance in stem cell research and cell-free therapies. It underscores the importance of bioengineers comprehending and manipulating EV activity to optimize the efficacy of tissue engineering and regenerative therapies.

Insight into the Functional Dynamics and Challenges of Exosomes in Pharmaceutical Innovation and Precision Medicine

Of all the numerous nanosized extracellular vesicles released by a cell, the endosomal-originated exosomes are increasingly recognized as potential therapeutics, owing to their inherent stability, low immunogenicity, and targeted delivery capabilities. This review critically evaluates the transformative potential of exosome-based modalities across pharmaceutical and precision medicine landscapes. Because of their precise targeted biomolecular cargo delivery, exosomes are posited as ideal candidates in drug delivery, enhancing regenerative medicine strategies, and advancing diagnostic technologies. Despite the significant market growth projections of exosome therapy, its utilization is encumbered by substantial scientific and regulatory challenges. These include the lack of universally accepted protocols for exosome isolation and the complexities associated with navigating the regulatory environment, particularly the guidelines set forth by the U.S. Food and Drug Administration (FDA). This review presents a comprehensive overview of current research trajectories aimed at addressing these impediments and discusses prospective advancements that could substantiate the clinical translation of exosomal therapies. By providing a comprehensive analysis of both the capabilities and hurdles inherent to exosome therapeutic applications, this article aims to inform and direct future research paradigms, thereby fostering the integration of exosomal systems into mainstream clinical practice.

Development of a Sampling and Storage Protocol of Extracellular Vesicles (EVs)-Establishment of the First EV Biobank for Polytraumatized Patients

In the last few years, several studies have emphasized the existence of injury-specific EV "barcodes" that could have significant importance for the precise diagnosis of different organ injuries in polytrauma patients. To expand the research potential of the NTF (network trauma research) biobank of polytraumatized patients, the NTF research group decided to further establish a biobank for EVs. However, until now, the protocols for the isolation, characterization, and storage of EVs for biobank purposes have not been conceptualized. Plasma and serum samples from healthy volunteers (n = 10) were used. Three EV isolation methods of high relevance for the work with patients' samples (ultracentrifugation, size exclusion chromatography, and immune magnetic bead-based isolation) were compared. EVs were quantified using nanoparticle tracking analysis, EV proteins, and miRNAs. The effects of different isolation solutions; the long storage of samples (up to 3 years); and the sensibility of EVs to serial freezing-thawing cycles and different storage conditions (RT, 4/-20/-80 °C, dry ice) were evaluated. The SEC isolation method was considered the most suitable for EV biobanking. We did not find any difference in the quantity of EVs between serum and plasma-EVs. The importance of particle-free PBS as an isolation solution was confirmed. Plasma that has been frozen for a long time can also be used as a source of EVs. Serial freezing-thawing cycles were found to affect the mean size of EVs but not their amount. The storage of EV samples for 5 days on dry ice significantly reduced the EV protein concentration.

Stem Cell Derived Extracellular Vesicle Therapy for Multiple Sclerosis, A Systematic Review and Meta-Analysis of Preclinical Studies

Stem cell therapy holds promise for multiple sclerosis (MS), with efficacy of different stem cell types reported across a range of preclinical MS animal models. While stem cell therapy has been approved for a small number of diseases in humans, extracellular vesicles (EVs) may provide an efficacious, cost-effective, and safer alternative to stem cell therapy. To this end, we conducted a systematic review with meta-analysis to assess the effectiveness of stem cell-derived secretome (EV and conditioned media (CM)) in animal models of MS. The data were extracted to calculate standardized mean differences for primary outcome measure of disease severity, using a random effect model. Additionally, several subgroup analyses were conducted to assess the impact of various study variables such as stem cell type and source, stem cell modification, route and time of administration, number of animals and animal's age, and EV isolation methods on secondary outcome. Publication quality and risk of bias were assessed. Overall, 19 preclinical studies were included in the meta-analysis where stem cell EV/CM was found to significantly reduce disease severity in EV-treated (SMD = 2, 95% CI: 1.18-2.83, P < .00001) and CM-treated animals (SMD = 2.58, 95% CI: 1.34-3.83, P < .00001) compared with controls. Our analysis indicated that stem cell secretome has a positive effect on reducing demyelination, systemic neuroinflammation, and disease severity in preclinical models of MS. These findings indicate a potential therapeutic effect that merits investigation and validation in clinical settings.

The novel insights of epithelial-derived exosomes in various fibrotic diseases

The characteristics of fibrosis include the abnormal accumulation of extracellular matrix proteins and abnormal tissue repair caused by injury, infection, and inflammation, leading to a significant increase in organ failure and mortality. Effective and precise treatments are urgently needed to halt and reverse the progression of fibrotic diseases. Exosomes are tiny vesicles derived from endosomes, spanning from 40 to 160 nanometers in diameter, which are expelled into the extracellular matrix environment by various cell types. They play a crucial role in facilitating cell-to-cell communication by transporting a variety of cargoes, including proteins, RNA, and DNA. Epithelial cells serve as the primary barrier against diverse external stimuli that precipitate fibrotic diseases. Numerous research suggests that exosomes from epithelial cells have a significant impact on several fibrotic diseases. An in-depth comprehension of the cellular and molecular mechanisms of epithelial cell-derived exosomes in fibrosis holds promise for advancing the exploration of novel diagnostic biomarkers and clinical drug targets. In this review, we expand upon the pathogenic mechanisms of epithelium-derived exosomes and highlight their role in the fibrotic process by inducing inflammation and activating fibroblasts. In addition, we are particularly interested in the bioactive molecules carried by epithelial-derived exosomes and their potential value in the diagnosis and treatment of fibrosis and delineate the clinical utility of exosomes as an emerging therapeutic modality, highlighting their potential application in addressing various medical conditions.

Immune system-related plasma extracellular vesicles in healthy aging

Objectives

To identify age-related plasma extracellular vehicle (EVs) phenotypes in healthy adults.

Methods

EV proteomics by high-resolution mass spectrometry to evaluate EV protein stability and discover age-associated EV proteins (n=4 with 4 serial freeze-thaws each); validation by high-resolution flow cytometry and EV cytokine quantification by multiplex ELISA (n=28 healthy donors, aged 18-83 years); quantification of WI-38 fibroblast cell proliferation response to co-culture with PKH67-labeled young and old plasma EVs. The EV samples from these plasma specimens were previously characterized for bilayer structure, intra-vesicle mitochondria and cytokines, and hematopoietic cell-related surface markers.

Results

Compared with matched exo-EVs (EV-depleted supernatants), endo-EVs (EV-associated) had higher mean TNF-α and IL-27, lower mean IL-6, IL-11, IFN-γ, and IL-17A/F, and similar mean IL-1β, IL-21, and IL-22 concentrations. Some endo-EV and exo-EV cytokine concentrations were correlated, including TNF-α, IL-27, IL-6, IL-1β, and IFN-γ, but not IL-11, IL-17A/F, IL-21 or IL-22. Endo-EV IFN-γ and exo-EV IL-17A/F and IL-21 declined with age. By proteomics and confirmed by flow cytometry, we identified age-associated decline of fibrinogen (FGA, FGB and FGG) in EVs. Age-related EV proteins indicated predominant origins in the liver and innate immune system. WI-38 cells (>95%) internalized similar amounts of young and old plasma EVs, but cells that internalized PKH67-EVs, particularly young EVs, underwent significantly greater cell proliferation.

Conclusion

Endo-EV and exo-EV cytokines function as different biomarkers. The observed healthy aging EV phenotype reflected a downregulation of EV fibrinogen subpopulations consistent with the absence of a pro-coagulant and pro-inflammatory condition common with age-related disease.

Small extracellular vesicles purification and scale-up

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

Exosome-based delivery strategies for tumor therapy: an update on modification, loading, and clinical application

Malignancy is a major public health problem and among the leading lethal diseases worldwide. Although the current tumor treatment methods have therapeutic effect to a certain extent, they still have some shortcomings such as poor water solubility, short half-life, local and systemic toxicity. Therefore, how to deliver therapeutic agent so as to realize safe and effective anti-tumor therapy become a problem urgently to be solved in this field. As a medium of information exchange and material transport between cells, exosomes are considered to be a promising drug delivery carrier due to their nano-size, good biocompatibility, natural targeting, and easy modification. In this review, we summarize recent advances in the isolation, identification, drug loading, and modification of exosomes as drug carriers for tumor therapy alongside their application in tumor therapy. Basic knowledge of exosomes, such as their biogenesis, sources, and characterization methods, is also introduced herein. In addition, challenges related to the use of exosomes as drug delivery vehicles are discussed, along with future trends. This review provides a scientific basis for the application of exosome delivery systems in oncological therapy.

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.

Clinical applications of stem cell-derived exosomes

Although stem cell-based therapy has demonstrated considerable potential to manage certain diseases more successfully than conventional surgery, it nevertheless comes with inescapable drawbacks that might limit its clinical translation. Compared to stem cells, stem cell-derived exosomes possess numerous advantages, such as non-immunogenicity, non-infusion toxicity, easy access, effortless preservation, and freedom from tumorigenic potential and ethical issues. Exosomes can inherit similar therapeutic effects from their parental cells such as embryonic stem cells and adult stem cells through vertical delivery of their pluripotency or multipotency. After a thorough search and meticulous dissection of relevant literature from the last five years, we present this comprehensive, up-to-date, specialty-specific and disease-oriented review to highlight the surgical application and potential of stem cell-derived exosomes. Exosomes derived from stem cells (e.g., embryonic, induced pluripotent, hematopoietic, mesenchymal, neural, and endothelial stem cells) are capable of treating numerous diseases encountered in orthopedic surgery, neurosurgery, plastic surgery, general surgery, cardiothoracic surgery, urology, head and neck surgery, ophthalmology, and obstetrics and gynecology. The diverse therapeutic effects of stem cells-derived exosomes are a hierarchical translation through tissue-specific responses, and cell-specific molecular signaling pathways. In this review, we highlight stem cell-derived exosomes as a viable and potent alternative to stem cell-based therapy in managing various surgical conditions. We recommend that future research combines wisdoms from surgeons, nanomedicine practitioners, and stem cell researchers in this relevant and intriguing research area.

Bone Marrow Mesenchymal Stem Cell-derived Exosomal microRNA-99b-5p Promotes Cell Growth of High Glucose-treated Human Umbilical Vein Endothelial Cells by Modulating THAP Domain Containing 2 Expression

INTRODUCTION

Bone marrow mesenchymal stem cell-derived exosomes (BMSC-exos) may function as novel candidates for treating diabetic wounds due to their ability to promote angiogenesis.

MATERIALS AND METHODS

This study investigated the effects of BMSC-exos on the growth and metastasis of human umbilical vein endothelial cells (HUVECs) treated with high glucose (HG). The exosomes were separated from BMSCs and identified. The cell phenotype was detected by 3-(4,5- dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide and 5-ethynyl-2'-deoxyuridine, wound healing, and transwell assays, while the number of tubes was measured via tube formation assay.

RESULT

The RNA and protein expression levels were studied using reverse transcription-quantitative polymerase chain reaction and western blotting, whereas integration of microRNA-99b-5p (miR-99b-5p) with THAP domain containing 2 (THAP2) was confirmed via dual-luciferase reporter and RNA pull-down assays. Results of transmission electron microscopy, nanoparticle tracking analysis, and laser scanning confocal microscopy revealed that exosomes were successfully separated from BMSCs and endocytosed into the cytoplasm by HUVECs. Similarly, BMSC-exos were found to promote the growth of HG-treated HUVECs, while their growth was inhibited by suppressing miR-99b-5p. THAP2 was found to bind to miR-99b-5p, where THAP2 inhibition reversed the miR-99b-5p-induced effects on cell growth, migration, and tube numbers.

CONCLUSION

In conclusion, miR-99b-5p in BMSC-exo protects HUVECs by negatively regulating THAP2 expression.

Extracellular vesicles derived from monomeric α-synuclein-treated microglia ameliorate neuroinflammation by delivery of miRNAs targeting PRAK

Parkinson's disease (PD) is characterized by the formation of Lewy body, which mainly contains misfolded α-synuclein. Microglial activation plays a role in neurodegeneration. The pathologically oligomeric α-synuclein promotes inflammatory microglia, while physiologically monomeric α-synuclein induces anti-inflammatory microglia, the relationship between these two forms in activating microglia and the molecular mechanism is essentially unknown. In this study, using in vivo and in vitro models, we challenged primary or BV2 microglia with exogenous stimuli including α-synuclein. We examined microglial activation and the underlying mechanism by Western blot, RT-PCR, ELISA, IF, FCM, miRNA sequencing and bioinformatic analysis. Oligomeric α-synuclein activatedmicroglia via theinvolvement of the PRAK/MK5 pathway. The specific PRAK inhibitor GLPG0259 could mitigate microglial activation insulted by oligomeric α-synuclein. Monomeric α-synuclein regulated theanti-inflammatory microglia by delivering microglia-derived extracellular vesicles (EVs) in vitro and in vivo. Furthersequencingand bioinformatic analysis of microglial EVs-associated miRNAs indicatedthatmost of these miRNAs targeted PRAK. These results suggest that PRAK serves as an intersection in microglial activation when challenged with conformationally different α-synuclein. EVs derived from microglia treated with monomeric α-synuclein promote anti-inflammatory microglia by delivering miRNAs that target PRAK into recipient microglia.

Treatment with Exosomes Derived from Mesenchymal Stem Cells: A New Window of Healing Science in Regenerative Medicine

Many studies have been conducted on the potential applications of mesenchymal stem cells (MSCs) over recent years due to their growing importance in regenerative medicine. Exosomes are considered cargos capable of transporting proteins, peptides, lipids, mRNAs, and growth factors. MSCsderived exosomes are also involved in the prevention or treatment of a variety of diseases, including cardiovascular diseases, neurological diseases, skin disorders, lung diseases, osteoarthritis, damaged tissue repair, and other diseases. This review attempted to summarize the importance of employing MSCs in regenerative medicine by gathering and evaluating information from current literature. The role of MSCs and the potential applications of MSCs-derived exosomes have also been discussed.

Exploring the role of polymers to overcome ongoing challenges in the field of extracellular vesicles

Extracellular vesicles (EVs) are naturally occurring nanoparticles released from all eucaryotic and procaryotic cells. While their role was formerly largely underestimated, EVs are now clearly established as key mediators of intercellular communication. Therefore, these vesicles constitute an attractive topic of study for both basic and applied research with great potential, for example, as a new class of biomarkers, as cell-free therapeutics or as drug delivery systems. However, the complexity and biological origin of EVs sometimes complicate their identification and therapeutic use. Thus, this rapidly expanding research field requires new methods and tools for the production, enrichment, detection, and therapeutic application of EVs. In this review, we have sought to explain how polymer materials actively contributed to overcome some of the limitations associated to EVs. Indeed, thanks to their infinite diversity of composition and properties, polymers can act through a variety of strategies and at different stages of EVs development. Overall, we would like to emphasize the importance of multidisciplinary research involving polymers to address persistent limitations in the field of EVs.

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.

Proteomics provides insights into the theranostic potential of extracellular vesicles

Extracellular vesicles (EVs) encompass a diverse range of membranous structures derived from cells, including exosomes and microvesicles. These vesicles are present in biological fluids and play vital roles in various physiological and pathological processes. They facilitate intercellular communication by enabling the exchange of proteins, lipids, and genetic material between cells. Understanding the cellular processes that govern EV biology is essential for unraveling their physiological and pathological functions and their potential clinical applications. Despite significant advancements in EV research in recent years, there is still much to learn about these vesicles. The advent of improved mass spectrometry (MS)-based techniques has allowed for a deeper characterization of EV protein composition, providing valuable insights into their roles in different physiological and pathological conditions. In this chapter, we provide an overview of proteomics studies conducted to identify the protein contents of EVs, which contribute to their therapeutic and pathological features. We also provided evidence on the potential of EV proteome contents as biomarkers for early disease diagnosis, progression, and treatment response, as well as factors that influence their composition. Additionally, we discuss the available databases containing information on EV proteome contents, and finally, we highlight the need for further research to pave the way toward their utilization in clinical settings.

Comparative Studies of Different Preservation Methods and Relative Freeze-Drying Formulations for Extracellular Vesicle Pharmaceutical Applications

Extracellular vesicles (EVs) have been studied for years for their role as effectors and mediators of cell-to-cell communication and their potential application to develop new and increasingly performing nanotechnological systems for the diagnosis and/or treatment of many diseases. Given all the EVs applications as just isolated, functionalized, or even engineered cellular-derived pharmaceuticals, the standardization of reliable and reproducible methods for their preservation is urgently needed. In this study, we isolated EVs from a healthy blood cell line, B lymphocytes, and compared the effectiveness of different storage methods and relative freeze-drying formulations to preserve some of the most important EVs' key features, i.e., concentration, mean size, protein content, and surface antigen's expression. To develop a preservation method that minimally affects the EVs' integrity and functionality, we applied the freeze-drying process in combination with different excipients. Since EVs are isolated not only from body fluids but also from culture media conditioned by the cells growing there, we decided to test both the effects of the traditional pharmaceutical excipient and of biological media to develop EVs solidified products with desirable appearance and performance properties. Results showed that some of the tested excipients, i.e., sugars in combination with dextran and glycine, successfully maintained the stability and integrity of EVs upon lyophilization. In addition, to evaluate the preservation of the EVs' biological activity, we assessed the cytotoxicity and internalization ability of the reconstituted EVs in healthy (B lymphocytes) and tumoral (Burkitt's lymphoma) cells. Reconstituted EVs demonstrated toxicity only toward the cancerous cells, opening new therapeutic opportunities for the oncological field. Furthermore, our study showed how some biological or cellular-conditioned fluids, commonly used in the field of cell cultures, can act not only as cryoprotectants but also as active pharmaceutical ingredients, significantly tuning the therapeutic effect of EVs, even increasing their cellular internalization.

Seminar: Extracellular Vesicles as Mediators of Environmental Stress in Human Disease

BACKGROUND

Extracellular vesicles (EVs), membrane-bound particles containing a variety of RNA types, DNA, proteins, and other macromolecules, are now appreciated as an important means of communication between cells and tissues, both in normal cellular physiology and as a potential indicator of cellular stress, environmental exposures, and early disease pathogenesis. Extracellular signaling through EVs is a growing field of research for understanding fundamental mechanisms of health and disease and for the potential for biomarker discovery and therapy development. EVs are also known to play important roles in mediating the effects of exposure to environmental stress.

OBJECTIVES

This seminar addresses the application of new tools and approaches for EV research, developed in part through the National Institutes of Health (NIH) Extracellular RNA Communication Program, and reflects presentations and discussions from a workshop held 27-28 September 2021 by the National Institute of Environmental Health Sciences (NIEHS) and the National Center for Advancing Translational Sciences (NCATS) on "Extracellular Vesicles, Exosomes, and Cell-Cell Signaling in Response to Environmental Stress." The panel of experts discussed current research on EVs and environmental exposures, highlighted recent advances in EV isolation and characterization, and considered research gaps and opportunities toward identifying and characterizing the roles for EVs in environmentally related diseases, as well as the current challenges and opportunities in this field.

DISCUSSION

The authors discuss the application of new experimental models, particularly organ-on-chip (OOC) systems and in vitro approaches and how these have the potential to extend findings in population-based studies of EVs in exposure-related diseases. Given the complex challenges of identifying cell-specific EVs related to environmental exposures, as well as the general heterogeneity and variability in EVs in blood and other accessible biological samples, there is a critical need for rigorous reporting of experimental methods and validation studies. The authors note that these efforts, combined with cross-disciplinary approaches, would ensure that future research efforts in environmental health studies on EV biomarkers are rigorous and reproducible. https://doi.org/10.1289/EHP12980.

In Vivo Electroporation Improves Retinal Delivery of Intravitreally Injected Exosomes

Purpose: Mesenchymal stem cell (MSC)-derived exosomes are promising therapeutic agents and natural nanoscale delivery platforms for treating degenerative retinal diseases. This study investigated the effect of electroporation on the retinal delivery of intravitreally administered MSC-derived exosomes in a murine model. Methods: Exosomes isolated from adipose tissue-derived MSCs were stained with ExoGlow exosome-specific dye and administered to the right eyes of 40 Sprague-Dawley rats. Electroporation was performed in 20 rats immediately after intravitreal injection (electroporation group); 5 square pulses of 40 V/cm for 50 ms each with 950-ms intervals were administered. The remaining 20 rats were assigned to the no-electroporation group. The eyeballs were harvested 24 h later for evaluation. The total number of fluorescent particles per hyperfield was counted from the retinal flat mounts to quantify the retinal delivery of exosomes. Tissue damage after electroporation was evaluated using retinal histological sections and a terminal deoxynucleotidyl transferase-mediated deoxyuridine nick end labeling (TUNEL) assay. Results: A significantly higher number of fluorescent particles per hyperfield were observed in the retinal flat mounts of the electroporation group compared with that in the no-electroporation group (599.0 ± 307.5 vs. 376.9 ± 175.4; P = 0.013). Retinal histological sections and TUNEL assays showed no signs of tissue damage after electroporation. Conclusions: In vivo electroporation can improve the retinal delivery of intravitreally injected exosomes.

Therapeutic Potential of Extracellular Vesicles from Different Stem Cells in Chronic Wound Healing

Wound healing has long been a complex problem, especially in chronic wounds. Although debridement, skin grafting, and antimicrobial dressings have been used to treat chronic wounds, their treatment period is long, expensive, and has specific rejection reactions. The poor treatment results of traditional methods have caused psychological stress to patients and a substantial economic burden to society. Extracellular vesicles (EVs) are nanoscale vesicles secreted by cells. They play an essential role in intercellular communication. Numerous studies have confirmed that stem cell-derived extracellular vesicles (SC-EVs) can inhibit overactive inflammation, induce angiogenesis, promote re-epithelization, and reduce scar formation. Therefore, SC-EVs are expected to be a novel cell-free strategy for chronic wound treatment. We first summarize the pathological factors that hinder wound healing and discuss how SC-EVs accelerate chronic wound repair. And then, we also compare the advantages and disadvantages of different SC-EVs for chronic wound treatment. Finally, we discuss the limitations of SC-EVs usage and provide new thoughts for future SC-EVs research in chronic wound treatment.

New strategies of neurodegenerative disease treatment with extracellular vesicles (EVs) derived from mesenchymal stem cells (MSCs)

Neurodegenerative diseases are characterized by the progressive loss of neurons and intricate interactions between different cell types within the affected regions. Reliable biomarkers that can accurately reflect disease activity, diagnose, and monitor the progression of neurodegenerative diseases are crucial for the development of effective therapies. However, identifying suitable biomarkers has been challenging due to the heterogeneous nature of these diseases, affecting specific subsets of neurons in different brain regions. One promising approach for promoting brain regeneration and recovery involves the transplantation of mesenchymal stem cells (MSCs). MSCs have demonstrated the ability to modulate the immune system, promote neurite outgrowth, stimulate angiogenesis, and repair damaged tissues, partially through the release of their extracellular vesicles (EVs). MSC-derived EVs retain some of the therapeutic characteristics of their parent MSCs, including their ability to regulate neurite outgrowth, promote angiogenesis, and facilitate tissue repair. This review aims to explore the potential of MSC-derived EVs as an emerging therapeutic strategy for neurodegenerative diseases, highlighting their role in modulating disease progression and promoting neuronal recovery. By elucidating the mechanisms by which MSC-derived EVs exert their therapeutic effects, we can advance our understanding and leverage their potential for the development of novel treatment approaches in the field of neurodegenerative diseases.

Treatment of Cardiac Fibrosis with Extracellular Vesicles: What Is Missing for Clinical Translation?

Heart failure is the leading cause of morbidity and mortality and currently affects more than 60 million people worldwide. A key feature in the pathogenesis of almost all forms of heart failure is cardiac fibrosis, which is characterized by excessive accumulation of extracellular matrix components in the heart. Although cardiac fibrosis is beneficial in the short term after acute myocardial injury to preserve the structural and functional integrity of the heart, persistent cardiac fibrosis contributes to pathological cardiac remodeling, leading to mechanical and electrical dysfunction of the heart. Despite its high prevalence, standard therapies specifically targeting cardiac fibrosis are not yet available. Cell-based approaches have been extensively studied as potential treatments for cardiac fibrosis, but several challenges have been identified during clinical translation. The observation that extracellular vesicles (EVs) derived from stem and progenitor cells exhibit some of the therapeutic effects of the parent cells has paved the way to overcome limitations associated with cell therapy. However, to make EV-based products a reality, standardized methods for EV production, isolation, characterization, and storage must be established, along with concrete evidence of their safety and efficacy in clinical trials. This article discusses EVs as novel therapeutics for cardiac fibrosis from a translational perspective.

The mRNA mobileome: challenges and opportunities for deciphering signals from the noise

Organismal communication entails encoding a message that is sent over space or time to a recipient cell, where that message is decoded to activate a downstream response. Defining what qualifies as a functional signal is essential for understanding intercellular communication. In this review, we delve into what is known and unknown in the field of long-distance messenger RNA (mRNA) movement and draw inspiration from the field of information theory to provide a perspective on what defines a functional signaling molecule. Although numerous studies support the long-distance movement of hundreds to thousands of mRNAs through the plant vascular system, only a small handful of these transcripts have been associated with signaling functions. Deciphering whether mobile mRNAs generally serve a role in plant communication has been challenging, due to our current lack of understanding regarding the factors that influence mRNA mobility. Further insight into unsolved questions regarding the nature of mobile mRNAs could provide an understanding of the signaling potential of these macromolecules.

Technological aspects of manufacturing and analytical control of biological nanoparticles

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

A standardized method for plasma extracellular vesicle isolation and size distribution analysis

The following protocol describes our workflow for isolation and quantification of plasma extracellular vesicles (EVs). It requires limited sample volume so that the scientific value of specimens is maximized. These steps include isolation of vesicles by automated size exclusion chromatography and quantification by tunable resistive pulse sensing. This workflow optimizes reproducibility by minimizing variations in processing, handling, and storage of EVs. EVs have significant diagnostic and therapeutic potential, but clinical application is limited by disparate methods of data collection. This standardized protocol is scalable and ensures efficient recovery of physiologically intact EVs that may be used in a variety of downstream biochemical and functional analyses. Simultaneous measurement quantifies EV concentration and size distribution absolutely. Absolute quantification corrects for variations in EV number and size, offering a novel method of standardization in downstream applications.

Mesenchymal Stem Cell-derived Exosomes: Novel Therapeutic Approach for Inflammatory Bowel Diseases

As double membrane-encapsulated nanovesicles (30-150 nm), exosomes (Exos) shuttle between different cells to mediate intercellular communication and transport active cargoes of paracrine factors. The anti-inflammatory and immunomodulatory activities of mesenchymal stem cell (MSC)-derived Exos (MSC-Exos) provide a rationale for novel cell-free therapies for inflammatory bowel disease (IBD). Growing evidence has shown that MSC-Exos can be a potential candidate for treating IBD. In the present review, we summarized the most critical advances in the properties of MSC-Exos, provided the research progress of MSC-Exos in treating IBD, and discussed the molecular mechanisms underlying these effects. Collectively, MSC-Exos had great potential for cell-free therapy in IBD. However, further studies are required to understand the full dimensions of the complex Exo system and how to optimize its effects.

Bax/Bcl-2 Expression Ratio Analysis of Rat Ovary Vitrified with Date Juice Concentrate as a Natural Extracellular Cryoprotectant

Background

The use of extremely low temperatures in vitrification is known to cause cryoinjury so that it can trigger the activation of the intrinsic apoptotic pathway, which can damage the structural integrity of the pre-antral follicle. Based on that, it is necessary to use an appropriate cryoprotectant to protect the preserved cell.

Aims

This study aimed to identify the potential use of date juice concentrate (DJC) as a natural extracellular cryoprotectant to suppress the rate of apoptosis after vitrification.

Settings and Design

This experimental research uses 24 samples of ovarian rats. Rats were fed and drank an ad libitum.

Materials and Methods

Ovaries were isolated in the proestrus phase, then processed into slides for immunohistochemistry (IHC) staining using anti-Bax and anti-Bcl-2 antibodies. IHC results were evaluated for the brown colour using ImageJ IHC Profiler. The results were analysed as an optical density and displayed in the Bax/Bcl-2 ratio.

Statistical Analysis Used

All data were statistically analysed with either parametric (analysis of various) or non-parametric (Kruskal-Wallis) tests.

Results

The combination of EG 7.5% + DJC 15% (KP2) showed the lowest Bax/Bcl-2 ratio in primordial and primary follicles. Meanwhile, the lowest Bax/Bcl-2 ratio in secondary follicles is found in KP4 (EG 15% + DJC 15%). The DJC is known to contain a dominant amount of glucose. The DJC shows antioxidant activity and contains antioxidant compounds, phenols and flavonoids.

Conclusion

The sugar content and antioxidant compounds of DJC can protect against follicle membrane damage, so the rate of intrinsic apoptosis pathway is also suppressed initially with Bax protein suppression in the mitochondrial membrane.

Opportunities and challenges of natural killer cell-derived extracellular vesicles

Extracellular vesicles (EVs) are increasingly recognized as important intermediaries of intercellular communication. They have significant roles in many physiological and pathological processes and show great promise as novel biomarkers of disease, therapeutic agents, and drug delivery tools. Existing studies have shown that natural killer cell-derived EVs (NEVs) can directly kill tumor cells and participate in the crosstalk of immune cells in the tumor microenvironment. NEVs own identical cytotoxic proteins, cytotoxic receptors, and cytokines as NK cells, which is the biological basis for their application in antitumor therapy. The nanoscale size and natural targeting property of NEVs enable precisely killing tumor cells. Moreover, endowing NEVs with a variety of fascinating capabilities via common engineering strategies has become a crucial direction for future research. Thus, here we provide a brief overview of the characteristics and physiological functions of the various types of NEVs, focusing on their production, isolation, functional characterization, and engineering strategies for their promising application as a cell-free modality for tumor immunotherapy.

Plant-Derived Exosome-like Nanoparticles for Biomedical Applications and Regenerative Therapy

Plant-derived exosome-like nanoparticles (PDENs) comprise various bioactive biomolecules. As an alternative cell-free therapeutic approach, they have the potential to deliver nano-bioactive compounds to the human body, and thus lead to various anti-inflammatory, antioxidant, and anti-tumor benefits. Moreover, it is known that Indonesia is one of the herbal centers of the world, with an abundance of unexplored sources of PDENs. This encouraged further research in biomedical science to develop natural richness in plants as a source for human welfare. This study aims to verify the potential of PDENs for biomedical purposes, especially for regenerative therapy applications, by collecting and analyzing data from the latest relevant research and developments.

Extracellular vesicles as a new horizon in the diagnosis and treatment of inflammatory eye diseases: A narrative review of the literature

Extracellular vesicles include exosomes, microvesicles, and apoptotic bodies. Their cargos contain a diverse variety of lipids, proteins, and nucleic acids that are involved in both normal physiology and pathology of the ocular system. Thus, studying extracellular vesicles may lead to a more comprehensive understanding of the pathogenesis, diagnosis, and even potential treatments for various diseases. The roles of extracellular vesicles in inflammatory eye disorders have been widely investigated in recent years. The term "inflammatory eye diseases" refers to a variety of eye conditions such as inflammation-related diseases, degenerative conditions with remarkable inflammatory components, neuropathy, and tumors. This study presents an overview of extracellular vesicles' and exosomes' pathogenic, diagnostic, and therapeutic values in inflammatory eye diseases, as well as existing and potential challenges.

Microbiota and plant-derived vesicles that serve as therapeutic agents and delivery carriers to regulate metabolic syndrome

The gut is a fundamental organ in controlling human health. Recently, researches showed that substances in the intestine can alter the course of many diseases through the intestinal epithelium, especially intestinal flora and exogenously ingested plant vesicles that can be transported over long distances to various organs. This article reviews the current knowledge on extracellular vesicles in modulating gut homeostasis, inflammatory response and numerous metabolic disease that share obesity as a co-morbidity. These complex systemic diseases that are difficult to cure, but can be managed by some bacterial and plant vesicles. Vesicles, due to their digestive stability and modifiable properties, have emerged as novel and targeted drug delivery vehicles for effective treatment of metabolic diseases.

MiR146a-loaded engineered exosomes released from silk fibroin patch promote diabetic wound healing by targeting IRAK1

Unhealable diabetic wounds need to be addressed with the help of newer, more efficacious strategies. Exosomes combined with biomaterials for sustained delivery of therapeutic agents are expected to bring new hope for chronic wound treatment. Here, the engineered exosomes modified for efficiently loading miR146a and attaching to silk fibroin patch (SFP) were demonstrated to promote diabetic wound healing. Silk fibroin binding peptide (SFBP) was screened through phage display, and SFBP-Gluc-MS2 (SGM) and pac-miR146a-pac fusion protein were constructed. The designed exosomes (SGM-Exos, miR146a-Exos, and SGM-miR146a-Exos) were isolated from the engineered placental mesenchymal stem cells (PMSCs) transduced with SGM or/and pac-miR146a-pac protein. Gluc signals indicated SGM-Exo@SFP markedly increased the binding rate and the stability of SGM-Exo. Moreover, the loading efficiency of miR146a in SGM-miR146a-Exos was ten-fold higher than that in miR146a-Exos. Superior to untreated, SGM-miR146a-Exo-only treated, and SFP-only treated groups, SGM-miR146a-Exo@SFP drived wound healing associated with less inflammation, collagen deposition, and neovascularization. The transcriptomics analysis suggested anti-inflammatory and regenerative effects with SGM-miR146a-Exo@SFP treatment. Here, we show efficient exosome@biomaterial-based miRNA delivery systems for regenerative medicine and tissue engineering.

Stem Cell-derived Extracellular Vesicles: A Promising Nano Delivery Platform to the Brain?

A very important cause of the frustration with drug therapy for central nervous system (CNS) diseases is the failure of drug delivery. The blood-brain barrier (BBB) prevents most therapeutic molecules from entering the brain while maintaining CNS homeostasis. Scientists are keen to develop new brain drug delivery systems to solve this dilemma. Extracellular vesicles (EVs), as a class of naturally derived nanoscale vesicles, have been extensively studied in drug delivery due to their superior properties. This review will briefly present current brain drug delivery strategies, including invasive and non-invasive techniques that target the brain, and the application of nanocarriers developed for brain drug delivery in recent years, especially EVs. The cellular origin of EVs affects the surface protein, size, yield, luminal composition, and other properties of EVs, which are also crucial in determining whether EVs are useful as drug carriers. Stem cell-derived EVs, which inherit the properties of parental cells and avoid the drawbacks of cell therapy, have always been favored by researchers. Thus, in this review, we will focus on the application of stem cell-derived EVs for drug delivery in the CNS. Various nucleic acids, proteins, and small-molecule drugs are loaded into EVs with or without modification and undergo targeted delivery to the brain to achieve their therapeutic effects. In addition, the challenges facing the clinical application of EVs as drug carriers will also be discussed. The directions of future efforts may be to improve drug loading efficiency and precise targeting.

Extracellular Vesicles as Therapeutic Resources in the Clinical Environment

The native role of extracellular vesicles (EVs) in mediating the transfer of biomolecules between cells has raised the possibility to use them as therapeutic vehicles. The development of therapies based on EVs is now expanding rapidly; here we will describe the current knowledge on different key points regarding the use of EVs in a clinical setting. These points are related to cell sources of EVs, isolation, storage, and delivery methods, as well as modifications to the releasing cells for improved production of EVs. Finally, we will depict the application of EVs therapies in clinical trials, considering the impact of the COVID-19 pandemic on the development of these therapies, pointing out that although it is a promising therapy for human diseases, we are still in the initial phase of its application to patients.

Liposomes or Extracellular Vesicles: A Comprehensive Comparison of Both Lipid Bilayer Vesicles for Pulmonary Drug Delivery

The rapid and non-invasive pulmonary drug delivery (PDD) has attracted great attention compared to the other routes. However, nanoparticle platforms, like liposomes (LPs) and extracellular vesicles (EVs), require extensive reformulation to suit the requirements of PDD. LPs are artificial vesicles composed of lipid bilayers capable of encapsulating hydrophilic and hydrophobic substances, whereas EVs are natural vesicles secreted by cells. Additionally, novel LPs-EVs hybrid vesicles may confer the best of both. The preparation methods of EVs are distinguished from LPs since they rely mainly on extraction and purification, whereas the LPs are synthesized from their basic ingredients. Similarly, drug loading methods into/onto EVs are distinguished whereby they are cell- or non-cell-based, whereas LPs are loaded via passive or active approaches. This review discusses the progress in LPs and EVs as well as hybrid vesicles with a special focus on PDD. It also provides a perspective comparison between LPs and EVs from various aspects (composition, preparation/extraction, drug loading, and large-scale manufacturing) as well as the future prospects for inhaled therapeutics. In addition, it discusses the challenges that may be encountered in scaling up the production and presents our view regarding the clinical translation of the laboratory findings into commercial products.