Elucidation of Exosome Migration across the Blood-Brain Barrier Model In Vitro

Involvement of Astrocytes in the Formation, Maintenance, and Function of the Blood-Brain Barrier

The blood-brain barrier (BBB) is a fundamental structure that protects the composition of the brain by determining which ions, metabolites, and nutrients are allowed to enter the brain from the blood or to leave it towards the circulation. The BBB is structurally composed of a layer of brain capillary endothelial cells (BCECs) bound to each other through tight junctions (TJs). However, its development as well as maintenance and properties are controlled by the other brain cells that contact the BCECs: pericytes, glial cells, and even neurons themselves. Astrocytes seem, in particular, to have a very important role in determining and controlling most properties of the BBB. Here, we will focus on these latter cells, since the comprehension of their roles in brain physiology has been continuously expanding, even including the ability to participate in neurotransmission and in complex functions such as learning and memory. Accordingly, pathological conditions that alter astrocytic functions can alter the BBB's integrity, thus compromising many brain activities. In this review, we will also refer to different kinds of in vitro BBB models used to study the BBB's properties, evidencing its modifications under pathological conditions.

Therapeutic potential of HUC-MSC-exos primed with IFN-γ against LPS-induced acute lung injury

Objectives

Human umbilical cord mesenchymal stem cells (HUC-MSCs) are pluripotent stem cells with anti-inflammatory and immunomodulatory properties used in the treatment of acute lung injury (ALI). However, the treatment of ALI using exosomes derived from HUC-MSCs (HUC-MSC-exos) primed with interferon-gamma (IFN-γ-exos) has not been described. This study investigated the effects of IFN-γ-exos on ALI.

Materials and Methods

IFN-γ primed and unprimed HUC-MSC-exos (IFN-γ-exos and CON-exos, respectively) were extracted, identified, and traced. A549 cells and mice subjected to lipopolysaccharide (LPS)-induced inflammation were treated with IFN-γ-exos or CON-exos. Viability; interleukin (IL)-1β, IL-6, tumor necrosis factor (TNF)-α, and reactive oxygen species (ROS) levels; NF-κB p65, and NLRP3 expression and histology and lung injury scores were measured in cell, supernatant or lung tissue.

Results

Indoleamine 2,3-dioxygenase (IDO) mRNA expression was elevated in HUC-MSCs primed with 5 ng/mL IFN-γ (P<0.001), and IFN-γ-exos and CON-exos were successfully extracted. LPS-induced inflammation resulted in decreased cell viability in A549 cells, and increased IL-1β, IL-6, TNF-α and ROS levels and NF-κB p65 and NLRP3 expression in A549 cells and mice(P<0.05 to P<0.001). Treatment with IFN-γ-exos and CON-exos increased cell viability and decreased the concentrations of IL-1β, and ROS, expression of NF-κB p65 and NLRP3, and the lung injury score, and these effects were more obvious for IFN-γ-exos(P<0.05 to P<0.001).

Conclusion

IFN-γ-exos reduced oxidative stress and inflammatory responses in LPS-induced A549 cells and mice. The result demonstrated the therapeutic potential of IFN-γ-exos in LPS-induced ALI.

Entry and exit of extracellular vesicles to and from the blood circulation

Extracellular vesicles (EVs) are biological nanoparticles that promote intercellular communication by delivering bioactive cargo over short and long distances. Short-distance communication takes place in the interstitium, whereas long-distance communication is thought to require transport through the blood circulation to reach distal sites. Extracellular vesicle therapeutics are frequently injected systemically, and diagnostic approaches often rely on the detection of organ-derived EVs in the blood. However, the mechanisms by which EVs enter and exit the circulation are poorly understood. Here, the lymphatic system and transport across the endothelial barrier through paracellular and transcellular routes are discussed as potential pathways for EV entry to and exit from the blood circulatory system.

Pathological and therapeutic effects of extracellular vesicles in neurological and neurodegenerative diseases

Extracellular vesicles are released by all cell types and contain proteins, microRNAs, mRNAs, and other bioactive molecules. Extracellular vesicles play an important role in intercellular communication and in the modulation of the immune system and neuroinflammation. The cargo of extracellular vesicles (e.g., proteins and microRNAs) is altered in pathological situations. Extracellular vesicles contribute to the pathogenesis of many pathologies associated with sustained inflammation and neuroinflammation, including cancer, diabetes, hyperammonemia and hepatic encephalopathy, and other neurological and neurodegenerative diseases. Extracellular vesicles may cross the blood-brain barrier and transfer pathological signals from the periphery to the brain. This contributes to inducing neuroinflammation and cognitive and motor impairment in hyperammonemia and hepatic encephalopathy and in neurodegenerative diseases. The mechanisms involved are beginning to be understood. For example, increased tumor necrosis factor α in extracellular vesicles from plasma of hyperammonemic rats induces neuroinflammation and motor impairment when injected into normal rats. Identifying the mechanisms by which extracellular vesicles contribute to the pathogenesis of these diseases will help to develop new treatments and diagnostic tools for their easy and early detection. In contrast, extracellular vesicles from mesenchymal stem cells have therapeutic utility in many of the above pathologies, by reducing inflammation and neuroinflammation and improving cognitive and motor function. These extracellular vesicles recapitulate the beneficial effects of mesenchymal stem cells and have advantages as therapeutic tools: they are less immunogenic, may not differentiate to malignant cells, cross the blood-brain barrier, and may reach more easily target organs. Extracellular vesicles from mesenchymal stem cells have beneficial effects in models of ischemic brain injury, Alzheimer's and Parkinson's diseases, hyperammonemia, and hepatic encephalopathy. Extracellular vesicles from mesenchymal stem cells modulate the immune system, promoting the shift from a pro-inflammatory to an anti-inflammatory state. For example, extracellular vesicles from mesenchymal stem cells modulate the Th17/Treg balance, promoting the anti-inflammatory Treg. Extracellular vesicles from mesenchymal stem cells may also act directly in the brain to modulate microglia activation, promoting a shift from a pro-inflammatory to an anti-inflammatory state. This reduces neuroinflammation and improves cognitive and motor function. Two main components of extracellular vesicles from mesenchymal stem cells which contribute to these beneficial effects are transforming growth factor-β and miR-124. Identifying the mechanisms by which extracellular vesicles from mesenchymal stem cells induce the beneficial effects and the main molecules (e.g., proteins and mRNAs) involved may help to improve their therapeutic utility. The aims of this review are to summarize the knowledge of the pathological effects of extracellular vesicles in different pathologies, the therapeutic potential of extracellular vesicles from mesenchymal stem cells to recover cognitive and motor function and the molecular mechanisms for these beneficial effects on neurological function.

Exploring the Impact of Exosomal Cargos on Osteosarcoma Progression: Insights into Therapeutic Potential

Osteosarcoma (OS) is a primary malignant bone tumor with high metastasis. Poor prognosis highlights a clinical need for novel therapeutic strategies. Exosomes, also known as extracellular vesicles, have been identified as essential players in the modulation of cancer. Recent studies have suggested that OS-derived exosomes can drive pro-tumorigenic or anti-tumorigenic phenotypes by transferring specific cargos, including proteins, nucleic acids, and metabolites, to neighboring cells, significantly impacting the regulation of cellular processes. This review discusses the advancement of exosomes and their cargos in OS. We examine how these exosomes contribute to the modulation of cellular phenotypes associated with tumor progression and metastasis. Furthermore, we explore the potential of exosomes as valuable biomarkers for diagnostics and prognostic purposes and their role in shaping innovative therapeutic strategies in OS treatment development.

Simultaneous ischemic regions targeting and BBB crossing strategy to harness extracellular vesicles for therapeutic delivery in ischemic stroke

Extracellular vesicles (EVs) derived from adipose-derived stem cells (ADSC-EVs) hold great promise for ischemic stroke treatment, but their therapeutic efficacy is greatly limited due to insufficient targeting ability. Previous reports focused on single ischemic targeting or blood-brain barrier (BBB) penetration, precise delivery to the brain parenchyma has not been fully considered. This study leveraged the targeting ability of RGD peptide and the cell penetrating ability of Angiopep-2 peptide to deliver ADSC-EVs precisely to the impaired brain parenchyma. We found that dual-modified EVs (RA-EVs) significantly enhanced the transcellular permeability across BBB in vitro, and not only targeted ischemic blood vessels but also achieved rapid accumulation in the ischemic lesion area after intravenous administration in vivo. RA-EVs further decreased the infarct volume, apoptosis, BBB disruption, and neurobehavioral deficits. RNA sequencing revealed the molecular regulation mechanism after administration. These findings demonstrate that dual-modification optimizes brain parenchymal targeting and highlights the significance of recruitment and penetration as a previously unidentified strategy for harnessing EVs for therapeutic delivery in ischemic stroke.

CRISPR-Cas9 delivery strategies with engineered extracellular vesicles

Therapeutic genome editing has the potential to cure diseases by directly correcting genetic mutations in tissues and cells. Recent progress in the CRISPR-Cas9 systems has led to breakthroughs in gene editing tools because of its high orthogonality, versatility, and efficiency. However, its safe and effective administration to target organs in patients is a major hurdle. Extracellular vesicles (EVs) are endogenous membranous particles secreted spontaneously by all cells. They are key actors in cell-to-cell communication, allowing the exchange of select molecules such as proteins, lipids, and RNAs to induce functional changes in the recipient cells. Recently, EVs have displayed their potential for trafficking the CRISPR-Cas9 system during or after their formation. In this review, we highlight recent developments in EV loading, surface functionalization, and strategies for increasing the efficiency of delivering CRISPR-Cas9 to tissues, organs, and cells for eventual use in gene therapies.

The emerging role of exosomes in communication between the periphery and the central nervous system

Exosomes, membrane-enclosed vesicles, are secreted by all types of cells. Exosomes can transport various molecules, including proteins, lipids, functional mRNAs, and microRNAs, and can be circulated to various recipient cells, leading to the production of local paracrine or distal systemic effects. Numerous studies have proved that exosomes can pass through the blood-brain barrier, thus, enabling the transfer of peripheral substances into the central nervous system (CNS). Consequently, exosomes may be a vital factor in the exchange of information between the periphery and CNS. This review will discuss the structure, biogenesis, and functional characterization of exosomes and summarize the role of peripheral exosomes deriving from tissues like the lung, gut, skeletal muscle, and various stem cell types in communicating with the CNS and influencing the brain's function. Then, we further discuss the potential therapeutic effects of exosomes in brain diseases and the clinical opportunities and challenges. Gaining a clearer insight into the communication between the CNS and the external areas of the body will help us to ascertain the role of the peripheral elements in the maintenance of brain health and illness and will facilitate the design of minimally invasive techniques for diagnosing and treating brain diseases.

Extracellular vesicles on the move: Traversing the complex matrix of tissues

Extracellular vesicles are small particles involved in intercellular signaling. They are produced by virtually all cell types, transport biological molecules, and are released into the extracellular space. Studies on extracellular vesicles have become more numerous in recent years, leading to promising research on their potential impact on health and disease. Despite significant progress in understanding the bioactivity of extracellular vesicles, most in vitro and in vivo studies overlook their transport through the extracellular matrix in tissues. The interaction or free diffusion of extracellular vesicles in their environment can provide valuable insights into their efficacy and function. Therefore, understanding the factors that influence the transport of extracellular vesicles in the extracellular matrix is essential for the development of new therapeutic approaches that involve the use of these extracellular vesicles. This review discusses the importance of the interaction between extracellular vesicles and the extracellular matrix and the different factors that influence their diffusion. In addition, we evaluate their role in tissue homeostasis, pathophysiology, and potential clinical applications. Understanding the complex interaction between extracellular vesicles and the extracellular matrix is critical in order to develop effective strategies to target specific cells and tissues in a wide range of clinical applications.

Regulatory T cells: A suppressor arm in post-stroke immune homeostasis

The activation of the immune system and the onset of pro- and anti-inflammatory responses play crucial roles in the pathophysiological processes of ischaemic stroke (IS). CD4+ regulatory T (Treg) cells is the main immunosuppressive cell population that is studied in the context of peripheral tolerance, autoimmunity, and the development of chronic inflammatory diseases. In recent years, more studies have focused on immune modulation after IS, and Treg cells have been demonstrated to be essential in the remission of inflammation, nerve regeneration, and behavioural recovery. However, the exact effects of Treg cells in the context of IS remain controversial, with some studies suggesting a negative correlation with stroke outcomes. In this review, we aim to provide a comprehensive overview of the current understanding of Treg cell involvement in post-stroke homeostasis. We summarized the literature focusing on the temporal changes in Treg cell populations after IS, the mechanisms of Treg cell-mediated immunomodulation in the brain, and the potential of Treg cell-based therapies for treatment. The purposes of the current article are to address the importance of Treg cells and inspire more studies to help physicians, as well as scientists, understand the whole map of immune responses during IS.

Extracellular Vesicles: Therapeutic Potential in Central Nervous System Trauma by Regulating Cell Death

CNS (central nervous system) trauma, which is classified as SCI (spinal cord injury) and TBI (traumatic brain injury), is gradually becoming a major cause of accidental death and disability worldwide. Many previous studies have verified that the pathophysiological mechanism underlying cell death and the subsequent neuroinflammation caused by cell death are pivotal factors in the progression of CNS trauma. Simultaneously, EVs (extracellular vesicles), membrane-enclosed particles produced by almost all cell types, have been proven to mediate cell-to-cell communication, and cell death involves complex interactions among molecules. EVs have also been proven to be effective carriers of loaded bioactive components to areas of CNS trauma. Therefore, EVs are promising therapeutic targets to cure CNS trauma. However, the link between EVs and various types of cell death in the context of CNS trauma remains unknown. Therefore, in this review, we summarize the mechanism underlying EV effects, the relationship between EVs and cell death and the pathophysiology underlying EV effects on the CNS trauma based on information in published papers. In addition, we discuss the prospects of applying EVs to the CNS as feasible therapeutic strategies for CNS trauma in the future.

miRNAs in the prognosis of triple-negative breast cancer: A review

Triple-Negative Breast Cancer (TNBC) is a highly aggressive and invasive type of breast cancer (BC) with high mortality rate wherein effective target medicaments are lacking. It is a very heterogeneous group with several subtypes that account for 10-20% of cancer among women globally, being negative for three most important receptors (estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2)), with an early and high recurrence resulting in poor survival rate. Therefore, a more thorough knowledge on carcinogenesis of TNBC is required for the development of personalized treatment options. miRNAs can either promote or suppress tumorigenesis and have been linked to a number of features of cancer progression, including proliferation, metastasis, apoptosis, and epithelial-mesenchymal transition (EMT). Recent miRNA research shows that there is great potential for the development of novel biomarkers as they have emerged as drivers of tumorigenesis and provide opportunities to target various components involved in TNBC, thus helping to solve this difficult-to-treat disease. In this review, we summarize the most relevant miRNAs that play an essential role in TNBC biology. Their role with regard to molecular mechanisms underlying TNBC progression has been discussed, and their potential use as therapeutic or prognostic markers to unravel the intricacy of TNBC based on the pieces of evidence obtained from various works of literature has been briefly addressed.

Anti-inflammatory effects of antenatal administration of stem cell derived extracellular vesicles in the brain of rat fetuses with congenital diaphragmatic hernia

PURPOSE

Congenital diaphragmatic hernia (CDH) survivors may experience neurodevelopmental impairment, whose etiology remains elusive. Preclinical evidence indicates that amniotic fluid stem cell extracellular vesicle (AFSC-EV) administration promotes lung development but their effects on other organs are unknown. Herein, we investigated the brain of rat fetuses with CDH for signs of inflammation and response to AFSC-EVs.

METHODS

CDH was induced by maternal nitrofen administration at E9.5. At E18.5, fetuses were injected intra-amniotically with saline or AFSC-EVs (isolated by ultracentrifugation, characterized as per MISEV guidelines). Fetuses from vehicle-gavaged dams served as controls. Groups were compared for: lung hypoplasia, TNFa and IL-1B brain expression, and activated microglia (Iba1) density in the subgranular zone (SGZ).

RESULTS

CDH lungs had fewer airspaces compared to controls, whereas AFSC-EV-treated lungs had rescued branching morphogenesis. Fluorescently labeled AFSC-EVs injected intra-amniotically into CDH fetuses had fluorescent signal in the brain. Compared to controls, the brain of CDH fetuses had higher TNFa and IL-1B levels, and increased activated microglia density. Conversely, the brain of AFSC-EV treated fetuses had inflammatory marker expression levels and microglia density similar to controls.

CONCLUSION

This study shows that the brain of rat fetuses with CDH has signs of inflammation that are abated by the intra-amniotic administration of AFSC-EVs.

Engineering CAR-NK cell derived exosome disguised nano-bombs for enhanced HER2 positive breast cancer brain metastasis therapy

HER2-positive breast cancer brain metastasis (HER2+ BCBM) is a refractory malignancy with a high recurrence rate and poor prognosis. The efficacies of conventional treatments, including radiation and the FDA-approved drug trastuzumab, are compromised due to their significant obstacles, such as limited penetration through the blood-brain barrier (BBB), off-target effects on HER2+ tumor cells, and systemic adverse reactions, ultimately resulting in suboptimal therapeutic outcomes. In order to address these challenges, a novel biomimetic nanoplatform was created, which consisted of a combination of chimeric antigen receptor-natural killer (CAR-NK) cell-derived exosomes (ExoCAR), and a nanobomb (referred to as Micelle). This nanoplatform, known as ExoCAR/T7@Micelle, was designed to enhance the effectiveness of antitumor treatment by disrupting ferroptosis defense mechanisms. Due to the transferrin receptor binding peptide (T7) modification and CAR expression on the exosome surface, the nanoplatform successfully traversed the blood-brain barrier and selectively targeted HER2+ breast cancer cells. Moreover, integration of the reactive oxygen species (ROS) -amplified and photodynamic therapy (PDT)-based nanobomb facilitated the spatiotemporal release of the cargos at specific sites. Upon systemic administration of ExoCAR/T7@Micelle, mice with orthotopic HER2+ BCBM demonstrated a robust antitumor response in vivo, leading to a significant extension in survival time. Furthermore, histological analyses and blood index studies revealed no discernible side effects. Collectively, this study is the first to indicate the possibility of HER2+ BCBM therapy with a CAR-NK cell-derived biomimetic drug delivery system.

Extracellular Vesicles as Possible Plasma Markers and Mediators in Patients with Sepsis-Associated Delirium-A Pilot Study

Patients with sepsis-associated delirium (SAD) show severe neurological impairment, often require an intensive care unit (ICU) stay and have a high risk of mortality. Hence, useful biomarkers for early detection of SAD are urgently needed. Extracellular vesicles (EVs) and their cargo are known to maintain normal physiology but also have been linked to numerous disease states. Here, we sought to identify differentially expressed proteins in plasma EVs from SAD patients as potential biomarkers for SAD. Plasma EVs from 11 SAD patients and 11 age-matched septic patients without delirium (non-SAD) were isolated by differential centrifugation, characterized by nanoparticle tracking analysis, transmission electron microscopy and Western blot analysis. Differential EV protein expression was determined by mass spectrometry and the resulting proteomes were characterized by Gene Ontology term and between-group statistics. As preliminary results because of the small group size, five distinct proteins showed significantly different expression pattern between SAD and non-SAD patients (p ≤ 0.05). In SAD patients, upregulated proteins included paraoxonase-1 (PON1), thrombospondin 1 (THBS1), and full fibrinogen gamma chain (FGG), whereas downregulated proteins comprised immunoglobulin (IgHV3) and complement subcomponent (C1QC). Thus, plasma EVs of SAD patients show significant changes in the expression of distinct proteins involved in immune system regulation and blood coagulation as well as in lipid metabolism in this pilot study. They might be a potential indicator for to the pathogenesis of SAD and thus warrant further examination as potential biomarkers, but further research is needed to expand on these findings in longitudinal study designs with larger samples and comprehensive polymodal data collection.

Exosomes Interactions with the Blood-Brain Barrier: Implications for Cerebral Disorders and Therapeutics

The Blood-Brain Barrier (BBB) is a selective structural and functional barrier between the circulatory system and the cerebral environment, playing an essential role in maintaining cerebral homeostasis by limiting the passage of harmful molecules. Exosomes, nanovesicles secreted by virtually all cell types into body fluids, have emerged as a major mediator of intercellular communication. Notably, these vesicles can cross the BBB and regulate its physiological functions. However, the precise molecular mechanisms by which exosomes regulate the BBB remain unclear. Recent research studies focused on the effect of exosomes on the BBB, particularly in the context of their involvement in the onset and progression of various cerebral disorders, including solid and metastatic brain tumors, stroke, neurodegenerative, and neuroinflammatory diseases. This review focuses on discussing and summarizing the current knowledge about the role of exosomes in the physiological and pathological modulation of the BBB. A better understanding of this regulation will improve our understanding of the pathogenesis of cerebral diseases and will enable the design of effective treatment strategies.

Role of exosomes in the development, diagnosis, prognosis and treatment of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the most common primary liver cancer. It is characterized by occult onset resulting in most patients being diagnosed at advanced stages and with poor prognosis. Exosomes are nanoscale vesicles with a lipid bilayer envelope released by various cells under physiological and pathological conditions, which play an important role in the biological information transfer between cells. There is growing evidence that HCC cell-derived exosomes may contribute to the establishment of a favorable microenvironment that supports cancer cell proliferation, invasion, and metastasis. These exosomes not only provide a versatile platform for diagnosis but also serve as a vehicle for drug delivery. In this paper, we review the role of exosomes involved in the proliferation, migration, and metastasis of HCC and describe their application in HCC diagnosis and treatment. We also discuss the prospects of exosome application in HCC and the research challenges.

Progress and Challenges in the Diagnosis and Treatment of Brain Cancer Using Nanotechnology

Primary brain cancer or brain cancer is the overgrowth of abnormal or malignant cells in the brain or its nearby tissues that form unwanted masses called brain tumors. People with malignant brain tumors suffer a lot, and the expected life span of the patients after diagnosis is often only around 14 months, even with the most vigorous therapies. The blood-brain barrier (BBB) is the main barrier in the body that restricts the entry of potential chemotherapeutic agents into the brain. The chances of treatment failure or low therapeutic effects are some significant drawbacks of conventional treatment methods. However, recent advancements in nanotechnology have generated hope in cancer treatment. Nanotechnology has shown a vital role starting from the early detection, diagnosis, and treatment of cancer. These tiny nanomaterials have great potential to deliver drugs across the BBB. Beyond just drug delivery, nanomaterials can be simulated to generate fluorescence to detect tumors. The current Review discusses in detail the challenges of brain cancer treatment and the application of nanotechnology to overcome those challenges. The success of chemotherapeutic treatment or the surgical removal of tumors requires proper imaging. Nanomaterials can provide imaging and therapeutic benefits for cancer. The application of nanomaterials in the diagnosis and treatment of brain cancer is discussed in detail by reviewing past studies.

Stem cells-derived exosomes alleviate neurodegeneration and Alzheimer's pathogenesis by ameliorating neuroinflamation, and regulating the associated molecular pathways

Amyloid beta (Aβ) aggregation and tau hyper phosphorylation (p-tau) are key molecular factors in Alzheimer's disease (AD). The abnormal formation and accumulation of Aβ and p-tau lead to the formation of amyloid plaques and neurofibrillary tangles (NFTs) which ultimately leads to neuroinflammation and neurodegeneration. β- and γ-secretases produce Aβ peptides via the amyloidogenic pathway, and several kinases are involved in tau phosphorylation. Exosomes, a recently developed method of intercellular communication, derived from neuronal stem cells (NSC-exos), are intriguing therapeutic options for AD. Exosomes have ability to cross the BBB hence highly recommended for brain related diseases and disorders. In the current study, we examined how NSC-exos could protect human neuroblastoma cells SH-SY5Y (ATCC CRL-2266). NSC-exos were derived from Human neural stem cells (ATCC-BYS012) by ultracentrifugation and the therapeutic effects of the NSC-exos were then investigated in vitro. NSC-exos controlled the associated molecular processes to drastically lower Aβ and p-tau. A dose dependent reduction in β- and γ-secretase, acetylcholinesterase, GSK3β, CDK5, and activated α-secretase activities was also seen. We further showed that BACE1, PSEN1, CDK5, and GSK-3β mRNA expression was suppressed and downregulated, while ADAM10 mRNA was increased. NSC- Exos downregulate NF-B/ERK/JNK-related signaling pathways in activated glial cells HMC3 (ATCC-CRL-3304) and reduce inflammatory mediators such iNOS, IL-1β, TNF-α, and IL-6, which are associated with neuronal inflammation. The NSC-exos therapy ameliorated the neurodegeneration of human neuroblastoma cells SH-SY5Y by enhancing viability. Overall, these findings support that exosomes produced from stem cells can be a neuro-protective therapy to alleviate AD pathology.

Clinical Theragnostic Signature of Extracellular Vesicles in Traumatic Brain Injury (TBI)

Traumatic brain injury (TBI) is a common cause of disability and fatality worldwide. Depending on the clinical presentation, it is a type of acquired brain damage that can be mild, moderate, or severe. The degree of patient's discomfort, prognosis, therapeutic approach, survival rates, and recurrence can all be strongly impacted by an accurate diagnosis made early on. The Glasgow Coma Scale (GCS), along with neuroimaging (MRI (Magnetic Resonance Imaging) and CT scan), is a neurological assessment tools used to evaluate and categorize the severity of TBI based on the patient's level of consciousness, eye opening, and motor response. Extracellular vesicles (EVs) are a growing domain, explaining neurological complications in a more detailed manner. EVs, in general, play a role in cellular communication. Its molecular signature such as DNA, RNA, protein, etc. contributes to the status (health or pathological stage) of the parental cell. Brain-derived EVs support more specific screening (diagnostic and prognostic) in TBI research. Therapeutic impact of EVs are more promising for aiding in TBI healing. It is nontoxic, biocompatible, and capable of crossing the blood-brain barrier (BBB) to transport therapeutic molecules. This review has highlighted the relationships between EVs and TBI theranostics, EVs and TBI-related clinical trials, and related research domain-associated challenges and solutions. This review motivates further exploration of associations between EVs and TBI and develops a better approach to TBI management.

The emerging role of exosomes in Schizophrenia

Schizophrenia (SCZ), a serious mental disorder, is one of the leading causes of disease burden worldwide. Exosomes, as a natural nanocarrier, are able to cross the blood-brain barrier (BBB) and play a key bridging role in central nervous system (CNS) communication, participating in important physiological processes such as neural regeneration, prominent plasticity, axonal support, and neuroinflammation. In recent years, exosomes have received widespread attention in the field of neurodegenerative diseases and mental disorders, especially Alzheimer's disease. However, there are few reviews on exosomes and SCZ. Therefore, we conducted a literature search in PubMed and Web of Science using the following search terms: "schizophrenia", "mental disorder", "central system", "exosome", "extracellular vesicles" to identify publications from January 2010 to December 2022. Our review summarized exosomes secreted by different cell types in the CNS and the double-edged role of exosomes in the development of SCZ, and discussed their future potential as biomarkers and therapeutic targets. In conclusion, this article provides an up-to-date overview of the current research on the involvement of exosomes in SCZ, while also highlighting the challenges that are currently faced in this field.

Extracellular vesicle-mediated targeting strategies for long-term health benefits in gestational diabetes

Extracellular vesicles (EVs) are critical mediators of cell communication, playing important roles in regulating molecular cross-talk between different metabolic tissues and influencing insulin sensitivity in both healthy and gestational diabetes mellitus (GDM) pregnancies. The ability of EVs to transfer molecular cargo between cells imbues them with potential as therapeutic agents. During pregnancy, the placenta assumes a vital role in metabolic regulation, with multiple mechanisms of placenta-mediated EV cross-talk serving as central components in GDM pathophysiology. This review focuses on the role of the placenta in the pathophysiology of GDM and explores the possibilities and prospects of targeting the placenta to address insulin resistance and placental dysfunction in GDM. Additionally, we propose the use of EVs as a novel method for targeted therapeutics in treating the dysfunctional placenta. The primary aim of this review is to comprehend the current status of EV targeting approaches and assess the potential application of these strategies in placental therapeutics, thereby delivering molecular cargo and improving maternal and fetal outcomes in GDM. We propose that EVs have the potential to revolutionize GDM management, offering hope for enhanced maternal-fetal health outcomes and more effective treatments.

Roles and therapeutic potential of different extracellular vesicle subtypes on traumatic brain injury

Traumatic brain injury (TBI) is a leading cause of injury-related disability and death around the world, but the clinical stratification, diagnosis, and treatment of complex TBI are limited. Due to their unique properties, extracellular vesicles (EVs) are emerging candidates for being biomarkers of traumatic brain injury as well as serving as potential therapeutic targets. However, the effects of different extracellular vesicle subtypes on the pathophysiology of traumatic brain injury are very different, or potentially even opposite. Before extracellular vesicles can be used as targets for TBI therapy, it is necessary to classify different extracellular vesicle subtypes according to their functions to clarify different strategies for EV-based TBI therapy. The purpose of this review is to discuss contradictory effects of different EV subtypes on TBI, and to propose treatment ideas based on different EV subtypes to maximize their benefits for the recovery of TBI patients. Video Abstract.

Potential Epigenetic Effects of Human Milk on Infants' Neurodevelopment

The advantages of human milk feeding, especially in preterm babies, are well recognized. Infants' feeding with breast milk lowers the likelihood of developing a diverse range of non-communicable diseases later in life and it is also associated with improved neurodevelopmental outcomes. Although the precise mechanisms through which human milk feeding is linked with infants' neurodevelopment are still unknown, potential epigenetic effects of breast milk through its bioactive components, including non-coding RNAs, stem cells and microbiome, could at least partly explain this association. Micro- and long-non-coding RNAs, enclosed in milk exosomes, as well as breast milk stem cells, survive digestion, reach the circulation and can cross the blood-brain barrier. Certain non-coding RNAs potentially regulate genes implicated in brain development and function, whereas nestin-positive stem cells can possibly differentiate into neural cells or/and act as epigenetic regulators in the brain. Furthermore, breast milk microbiota contributes to the establishment of infant's gut microbiome, which is implicated in brain development via epigenetic modifications and key molecules' regulation. This narrative review provides an updated analysis of the relationship between breast milk feeding and infants' neurodevelopment via epigenetics, pointing out how breast milk's bioactive components could have an impact on the neurodevelopment of both full-term and preterm babies.

Mesenchymal Stem Cell-Derived Extracellular Vesicles: An Emerging Diagnostic and Therapeutic Biomolecules for Neurodegenerative Disabilities

Mesenchymal stem cells (MSCs) are a type of versatile adult stem cells present in various organs. These cells give rise to extracellular vesicles (EVs) containing a diverse array of biologically active elements, making them a promising approach for therapeutics and diagnostics. This article examines the potential therapeutic applications of MSC-derived EVs in addressing neurodegenerative disorders such as Alzheimer's disease (AD), multiple sclerosis (MS), Parkinson's disease (PD), amyotrophic lateral sclerosis (ALS), and Huntington's disease (HD). Furthermore, the present state-of-the-art for MSC-EV-based therapy in AD, HD, PD, ALS, and MS is discussed. Significant progress has been made in understanding the etiology and potential treatments for a range of neurodegenerative diseases (NDs) over the last few decades. The contents of EVs are carried across cells for intercellular contact, which often results in the control of the recipient cell's homeostasis. Since EVs represent the therapeutically beneficial cargo of parent cells and are devoid of many ethical problems connected with cell-based treatments, they offer a viable cell-free therapy alternative for tissue regeneration and repair. Developing innovative EV-dependent medicines has proven difficult due to the lack of standardized procedures in EV extraction processes as well as their pharmacological characteristics and mechanisms of action. However, recent biotechnology and engineering research has greatly enhanced the content and applicability of MSC-EVs.

The role of exercise parameters on small extracellular vesicles and microRNAs cargo in preventing neurodegenerative diseases

Physical activity (PA), which includes exercise, can reduce the risk of developing various non-communicable diseases, including neurodegenerative diseases (NDs), and mitigate their adverse effects. However, the mechanisms underlying this ability are not yet fully understood. Among several possible mechanisms proposed, such as the stimulation of brain-derived neurotrophic factor (BDNF), endothelial nitric oxide synthase (eNOS), insulin-like growth factor-1 (IGF-1), vascular endothelial growth factor (VEGF), and nerve growth factor (NGF), the possible involvement of particular vesicular structures enclosed in lipid membranes known as extracellular vesicles (EVs) has recently been investigated. These EVs would appear to exert a paracrine and systemic action through their ability to carry various molecules, particularly so-called microRNAs (miRNAs), performing a function as mediators of intercellular communication. Interestingly, EVs and miRNAs are differentially expressed following PA, but evidence on how different exercise parameters may differentially affect EVs and the miRNAs they carry is still scarce. In this review we summarized the current human findings on the effects of PA and different exercise parameters exerted on EVs and their cargo, focusing on miRNAs molecules, and discussing how this may represent one of the biological mechanisms through which exercise contributes to preventing and slowing NDs.

Increased plasma levels of circPTP4A2 and circTLK2 are associated with stroke injury

OBJECTIVE

Accumulating studies have shown that circulating circular RNAs (circRNAs) represent novel biomarkers for many human diseases. We investigated whether plasma circPTP4A2 and circTLK2 levels are associated with stroke severity, infarct volume, stroke etiology, and functional outcome in acute ischemic stroke (AIS) patients.

METHODS

We applied quantitative real-time PCR (qPCR) to measure plasma circPTP4A2 and circTLK2 levels of 236 AIS patients within 72 h of symptoms onset and 136 healthy controls. We further assessed the National Institutes of Health Stroke Scale (NIHSS), infarct size, the Trial of Org 10172 in Acute Stroke Treatment (TOAST) classification and the 90-day modified Rankin scale (mRS) for each patient.

RESULTS

At admission, plasma circPTP4A2 and circTLK2 levels in patients with moderate to severe stroke were significantly higher compared to those with mild stroke. Logistic regression and receiver-operating characteristic (ROC) curve analyses indicated that they might function as predictive biomarkers for moderate to severe stroke. We also observed a medium positive correlation between these two circRNAs and NIHSS. Plasma circPTP4A2 and circTLK2 levels were slight positively correlated with cerebral infarct volume only in anterior circulation infarction (ACI) patients. Levels of both circPTP4A2 and circTLK2 were closely related with large artery atherosclerosis (LAA) stroke. Moreover, changes within 7 days after admission in circPTP4A2 and circTLK2 were able to predict unfavorable clinical outcome 90 days after AIS.

INTERPRETATION

These results demonstrate that plasma circPTP4A2 and circTLK2 strongly correlated with severity, subtypes and prognosis of AIS, and they could serve as promising biomarkers.

The role of Extracellular Genomic Materials (EGMs) in psychiatric disorders

Extracellular Genomic Materials (EGMs) are the nucleic acids secreted or released from all types of cells by endogenous or exogenous stimuli through varying mechanisms into the extracellular region and inevitably to all biological fluids. EGMs could be found as free, protein-bound, and/ or with vesicles. EGMs can potentially have immunophenotypic and/or genotypic characteristics of a cell of origin, travel to distant organs, and interact with the new microenvironment. To achieve all, EGMs might bi-directionally transit through varying membranes, including the blood-brain barrier. Such ability provides the transfer of any information related to the pathophysiological changes in psychiatric disorders in the brain to the other distant organ systems or vice versa. In this article, many aspects of EGMs have been elegantly reviewed, including their potential in diagnosis as biomarkers, application in treatment modalities, and functional effects in the pathophysiology of psychiatric disorders. The psychiatric disorders were studied under subgroups of Schizophrenia spectrum disorders, bipolar disorder, depressive disorders, and an autism spectrum disorders. EGMs provide a robust and promising tool in clinics for prognosis and diagnosis. The successful application of EGMs into treatment modalities might further provide encouraging outcomes for researchers and clinicians in psychiatric disorders.

The Long Journey of Extracellular Vesicles towards Global Scientific Acclamation

Extracellular vesicles (EVs) are a heterogeneous class of cell-derived vesicles that are responsible for eliciting a wide array of biological processes. After decades of intense investigation, the therapeutic potential of EVs will be finally explored in a series of upcoming clinical trials. EVs are rapidly changing the understanding of human physiology and will undoubtedly transform the field of medicine. The applicability of EVs as diagnostic biomarkers and treatment vectors has captured the attention of the scientific community and investors, facilitating the rapid progression of numerous EVs-based platforms. This mini-review provides an outline of the pioneering discoveries, and their respective significances, on progressing EVs toward clinical use. We focus the attention of the readers on several promising classes of EVs that hold major opportunities to translate in clinical practice. Market analysis and future challenges facing EVs-based therapies are also discussed.

Running from stress: a perspective on the potential benefits of exercise-induced small extracellular vesicles for individuals with major depressive disorder

Aerobic exercise promotes beneficial effects in the brain including increased synaptic plasticity and neurogenesis and regulates neuroinflammation and stress response via the hypothalamic-pituitary-adrenal axis. Exercise can have therapeutic effects for numerous brain-related pathologies, including major depressive disorder (MDD). Beneficial effects of aerobic exercise are thought to be mediated through the release of "exerkines" including metabolites, proteins, nucleic acids, and hormones that communicate between the brain and periphery. While the specific mechanisms underlying the positive effects of aerobic exercise on MDD have not been fully elucidated, the evidence suggests that exercise may exert a direct or indirect influence on the brain via small extracellular vesicles which have been shown to transport signaling molecules including "exerkines" between cells and across the blood-brain barrier (BBB). sEVs are released by most cell types, found in numerous biofluids, and capable of crossing the BBB. sEVs have been associated with numerous brain-related functions including neuronal stress response, cell-cell communication, as well as those affected by exercise like synaptic plasticity and neurogenesis. In addition to known exerkines, they are loaded with other modulatory cargo such as microRNA (miRNA), an epigenetic regulator that regulates gene expression levels. How exercise-induced sEVs mediate exercise dependent improvements in MDD is unknown. Here, we perform a thorough survey of the current literature to elucidate the potential role of sEVs in the context of neurobiological changes seen with exercise and depression by summarizing studies on exercise and MDD, exercise and sEVs, and finally, sEVs as they relate to MDD. Moreover, we describe the links between peripheral sEV levels and their potential for infiltration into the brain. While literature suggests that aerobic exercise is protective against the development of mood disorders, there remains a scarcity of data on the therapeutic effects of exercise. Recent studies have shown that aerobic exercise does not appear to influence sEV size, but rather influence their concentration and cargo. These molecules have been independently implicated in numerous neuropsychiatric disorders. Taken together, these studies suggest that concentration of sEVs are increased post exercise, and they may contain specifically packaged protective cargo representing a novel therapeutic for MDD.

Alternating Magnetic Field-Promoted Nanoparticle Mixing: The On-Chip Immunocapture of Serum Neuronal Exosomes for Parkinson's Disease Diagnostics

The analysis of cargo proteins in exosome subpopulations has considerable value in diagnostics but a translatable impact has been limited by lengthy or complex exosome extraction protocols. We describe herein a scalable, fast, and low-cost exosome extraction using an alternating (AC) magnetic field to support the dynamic mixing of antibody-coated magnetic beads (MBs) with serum samples within 3D-printed microfluidic chips. Zwitterionic polymer-coated MBs are, specifically, magnetically agitated and support ultraclean exosome capture efficiencies >70% from <50 μL of neat serum in 30 min. Applied herein to the immunocapture of neuronal exosomes using anti-L1CAM antibodies, prior to the array-based assaying of α-synuclein (α-syn) content by a standard duplex electrochemical sandwich ELISA, sub pg/mL detection was possible with an excellent coefficient of variation and a sample-to-answer time of ∼75 min. The high performance and semiautomation of this approach hold promise in underpinning low-cost Parkinson's disease diagnostics and is of value in exosomal biomarker analyses more generally.

Cell-derived nanovesicle-mediated drug delivery to the brain: Principles and strategies for vesicle engineering

Developing strategies toward safe and effective drug delivery into the central nervous system (CNS) with improved targeting abilities and reduced off-target effects is crucial. CNS-targeted drug carriers made of synthetic molecules raise concerns about their biodegradation, clearance, immune responses, and neurotoxicity. Cell-derived nanovesicles (CDNs) have recently been applied in CNS-targeted drug delivery, because of their intrinsic stability, biocompatibility, inherent homing capability, and the ability to penetrate through biological barriers, including the blood-brain barrier. Among these CDNs, extracellular vesicles and exosomes are the most studied because their surface can be engineered and modified to cater to brain targeting. In this review, we focus on the application of CDNs in brain-targeted drug delivery to treat neurological diseases. We cover recently developed methods of exosome derivation and engineering, including exosome-like particles, hybrid exosomes, exosome-associated adeno-associated viruses, and envelope protein nanocages. Finally, we discuss the limitations and project the future development of the CDN-based brain-targeted delivery systems, and conclude that engineered CDNs hold great potential in the treatment of neurological diseases.

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.

CmPn/CmP Signaling Networks in the Maintenance of the Blood Vessel Barrier

Cerebral cavernous malformations (CCMs) arise when capillaries within the brain enlarge abnormally, causing the blood-brain barrier (BBB) to break down. The BBB serves as a sophisticated interface that controls molecular interactions between the bloodstream and the central nervous system. The neurovascular unit (NVU) is a complex structure made up of neurons, astrocytes, endothelial cells (ECs), pericytes, microglia, and basement membranes, which work together to maintain blood-brain barrier (BBB) permeability. Within the NVU, tight junctions (TJs) and adherens junctions (AJs) between endothelial cells play a critical role in regulating the permeability of the BBB. Disruptions to these junctions can compromise the BBB, potentially leading to a hemorrhagic stroke. Understanding the molecular signaling cascades that regulate BBB permeability through EC junctions is, therefore, essential. New research has demonstrated that steroids, including estrogens (ESTs), glucocorticoids (GCs), and metabolites/derivatives of progesterone (PRGs), have multifaceted effects on blood-brain barrier (BBB) permeability by regulating the expression of tight junctions (TJs) and adherens junctions (AJs). They also have anti-inflammatory effects on blood vessels. PRGs, in particular, have been found to play a significant role in maintaining BBB integrity. PRGs act through a combination of its classic and non-classic PRG receptors (nPR/mPR), which are part of a signaling network known as the CCM signaling complex (CSC). This network couples both nPR and mPR in the CmPn/CmP pathway in endothelial cells (ECs).

Plant-derived nanoparticles and plant virus nanoparticles: Bioactivity, health management, and delivery potential

Natural plants have acquired an increasing attention in biomedical research. Recent studies have revealed that plant-derived nanoparticles (PDNPs), which are nano-sized membrane vesicles released by plants, are one of the important material bases for the health promotion of natural plants. A great deal of research in this field has focused on nanoparticles derived from fresh vegetables and fruits. Generally, PDNPs contain lipids, proteins, nucleic acids, and other active small molecules and exhibit unique biological regulatory activity and editability. Specifically, they have emerged as important mediators of intercellular communication, and thus, are potentially suitable for therapeutic purposes. In this review, PDNPs were extensively explored; by evaluating them systematically starting from the origin and isolation, toward their characteristics, including morphological compositions, biological functions, and delivery potentials, as well as distinguishing them from plant-derived exosomes and highlighting the limitations of the current research. Meanwhile, we elucidated the variations in PDNPs infected by pathogenic microorganisms and emphasized on the biological functions and characteristics of plant virus nanoparticles. After clarifying these problems, it is beneficial to further research on PDNPs in the future and develop their clinical application value.

Astrocyte-Derived Exosomes Differentially Shape T Cells' Immune Response in MS Patients

Astrocytes, the most abundant group of glia cells in the brain, provide support for neurons and indicate multiple various functions in the central nervous system (CNS). Growing data additionally describe their role in the regulation of immune system activity. They exert their function not only by direct contact with other cell types, but also through an indirect method, e.g., by secreting various molecules. One such structure is extracellular vesicles, which are important mediators of crosstalk between cells. In our study, we observed that the impact of exosomes derived from astrocytes with various functional phenotype differently affect the immune response of CD4+ T cells, both from healthy individuals and from patients with multiple sclerosis (MS). Astrocytes, by modulating exosome cargo, impacts the release of IFN-γ, IL-17A and CCL2 in our experimental conditions. Considering the proteins concentration in cell culture supernatants and the cellular percentage of Th phenotypes, it could be stated that human astrocytes, by the release of exosomes, are able to modify the activity of human T cells.

Small Extracellular Vesicles' miRNAs: Biomarkers and Therapeutics for Neurodegenerative Diseases

Neurodegenerative diseases are critical in the healthcare system as patients suffer from progressive diseases despite currently available drug management. Indeed, the growing ageing population will burden the country's healthcare system and the caretakers. Thus, there is a need for new management that could stop or reverse the progression of neurodegenerative diseases. Stem cells possess a remarkable regenerative potential that has long been investigated to resolve these issues. Some breakthroughs have been achieved thus far to replace the damaged brain cells; however, the procedure's invasiveness has prompted scientists to investigate using stem-cell small extracellular vesicles (sEVs) as a non-invasive cell-free therapy to address the limitations of cell therapy. With the advancement of technology to understand the molecular changes of neurodegenerative diseases, efforts have been made to enrich stem cells' sEVs with miRNAs to increase the therapeutic efficacy of the sEVs. In this article, the pathophysiology of various neurodegenerative diseases is highlighted. The role of miRNAs from sEVs as biomarkers and treatments is also discussed. Lastly, the applications and delivery of stem cells and their miRNA-enriched sEVs for treating neurodegenerative diseases are emphasised and reviewed.

Insights into Exosome Transport through the Blood-Brain Barrier and the Potential Therapeutical Applications in Brain Diseases

Drug delivery to the central nervous system (CNS) is limited due to the presence of the blood-brain barrier (BBB), a selective physiological barrier located at the brain microvessels that regulates the flow of cells, molecules and ions between the blood and the brain. Exosomes are nanosized extracellular vesicles expressed by all cell types and that function as cargos, allowing for communication between the cells. The exosomes were shown to cross or regulate the BBB in healthy and disease conditions. However, the mechanistic pathways by which exosomes cross the BBB have not been fully elucidated yet. In this review, we explore the transport mechanisms of exosomes through the BBB. A large body of evidence suggests that exosome transport through the BBB occurs primarily through transcytosis. The transcytosis mechanisms are influenced by several regulators. Inflammation and metastasis also enhance exosome trafficking across the BBB. We also shed light on the therapeutical applications of exosomes for treating brain diseases. Further investigations are essential to provide clearer insights related to trafficking of exosomes across the BBB and disease treatment.

Mesenchymal Stem Cell-Derived Exosomes in Ophthalmology: A Comprehensive Review

Over the past decade, the field of mesenchymal stem cell (MSC) therapy has exhibited rapid growth. Due to their regenerative, reparatory, and immunomodulatory capacities, MSCs have been widely investigated as therapeutic agents in the cell-based treatment of chronic ophthalmic pathologies. However, the applicability of MSC-based therapy is limited by suboptimal biocompatibility, penetration, and delivery to the target ocular tissues. An emerging body of research has elucidated the role of exosomes in the biological functions of MSCs, and that MSC-derived extracellular vesicles (EVs) possess anti-inflammatory, anti-apoptotic, tissue repairing, neuroprotective, and immunomodulatory properties similar to MSCs. The recent advances in MSCs-derived exosomes can serve as solutions to the challenges faced by MSCs-therapy. Due to their nano-dimensions, MSC-derived exosomes can rapidly penetrate biological barriers and reach immune-privileged organs, allowing for efficient delivery of therapeutic factors such as trophic and immunomodulatory agents to ocular tissues that are typically challenging to target by conventional therapy and MSCs transplantation. In addition, the use of EVs minimizes the risks associated with mesenchymal stem cell transplantation. In this literature review, we focus on the studies published between 2017 and 2022, highlighting the characteristics of EVs derived from MSCs and their biological functions in treating anterior and posterior segment ocular diseases. Additionally, we discuss the potential use of EVs in clinical settings. Rapid advancements in regenerative medicine and exosome-based drug delivery, in conjunction with an increased understanding of ocular pathology and pharmacology, hold great promise for the treatment of ocular diseases. The potential of exosome-based therapies is exciting and can revolutionize the way we approach these ocular conditions.

Transplantation of Exercise-Induced Extracellular Vesicles as a Promising Therapeutic Approach in Ischemic Stroke

Clinical evidence affirms physical exercise is effective in preventive and rehabilitation approaches for ischemic stroke. This sustainable efficacy is independent of cardiovascular risk factors and associates substantial reprogramming in circulating extracellular vesicles (EVs). The intricate journey of pluripotent exercise-induced EVs from parental cells to the whole-body and infiltration to cerebrovascular entity offers several mechanisms to reduce stroke incidence and injury or accelerate the subsequent recovery. This review delineates the potential roles of EVs as prospective effectors of exercise. The candidate miRNA and peptide cargo of exercise-induced EVs with both atheroprotective and neuroprotective characteristics are discussed, along with their presumed targets and pathway interactions. The existing literature provides solid ground to hypothesize that the rich vesicles link exercise to stroke prevention and rehabilitation. However, there are several open questions about the exercise stressors which may optimally regulate EVs kinetic and boost brain mitochondrial adaptations. This review represents a novel perspective on achieving brain fitness against stroke through transplantation of multi-potential EVs generated by multi-parental cells, which is exceptionally reachable in an exercising body.

Unpacking the Role of Extracellular Vesicles in Ischemic and Hemorrhagic Stroke: Pathophysiology and Therapeutic Implications

Stroke is a leading cause of death and disability worldwide. Inflammation and microvascular dysfunction have been associated with brain injury and long-term disability after both ischemic and hemorrhagic stroke. Recent studies have suggested a potential role of extracellular vesicles (EVs) as a link underlying these pathogenic processes. EVs are cell-derived particles enveloped by a lipid bilayer, containing proteins, lipids, and nucleic acids. From a functional standpoint, EVs can facilitate intercellular communication, including across the blood-brain barrier (BBB). Recent advances in EV research have shown a preferential release of EVs from specific cell types in the context of stroke, some of which were associated with increased neuroinflammation, microvascular dysfunction, and neuronal cytotoxicity while others offered a degree of neuroprotection. However, one historic challenge in the studies of EVs in stroke is the lack of consistent definitions and methods to analyze EVs, only recently updated in the MISEV2018 guidelines. Given limitations and complexity in the treatment of stroke, particularly delivery of therapeutics across the BBB, increasing attention has been paid towards manipulating EVs as one vehicle that can permit targeted therapeutic delivery to the central nervous system. These discoveries point towards a future where a better understanding of EVs will advance our knowledge of stroke-associated mechanisms of cerebral and systemic injury and contribute to the development of novel treatments. Here, we review the role that EVs play in ischemic and hemorrhagic stroke.

Novel Developments to Enable Treatment of CNS Diseases with Targeted Drug Delivery

The blood-brain barrier (BBB) is a major hurdle for the development of systemically delivered drugs against diseases of the central nervous system (CNS). Because of this barrier there is still a huge unmet need for the treatment of these diseases, despite years of research efforts across the pharmaceutical industry. Novel therapeutic entities, such as gene therapy and degradomers, have become increasingly popular in recent years, but have not been the focus for CNS indications so far. To unfold their full potential for the treatment of CNS diseases, these therapeutic entities will most likely have to rely on innovative delivery technologies. Here we will describe and assess approaches, both invasive and non-invasive, that can enable, or at least increase, the probability of a successful drug development of such novel therapeutics for CNS indications.

The role of exosomes in pathogenesis and the therapeutic efficacy of mesenchymal stem cell-derived exosomes against Parkinson's disease

Parkinson's disease (PD) is a chronic, progressive, neurodegenerative disease. The predominant pathology of PD is the loss of dopaminergic cells in the substantia nigra. Cell transplantation is a strategy with significant potential for treating PD; mesenchymal stem cells (MSCs) are a tremendous therapeutic cell source because they are easily accessible. MSC-derived exosomes with potential protective action in lesioned sites serve as an essential promoter of neuroprotection, and neurodifferentiation, by modulating neural stem cells, neurons, glial cells, and axonal growth in vitro and in vivo environments. The biological properties of MSC-derived exosomes have been proposed as a beneficial tool in different pathological conditions, including PD. Therefore, in this review, we assort the current understanding of MSC-derived exosomes as a new possible therapeutic strategy for PD by providing an overview of the potential role of miRNAs as a component of exosomes in the cellular and molecular basis of PD.

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.

Exosome-Based Therapy for Ischemic Stroke: A Bibliometric Analysis of Current Trends and Future Directions

BACKGROUND

Stroke is a leading cause of mortality and disability worldwide. Exosomes, or small extracellular vesicles with signaling properties, have recently been identified as novel mechanisms for stroke treatment. This study aims to use bibliometric techniques to identify current research trends and future directions of exosome-based stroke therapy.

METHODS

The Web of Science Core Collection was searched using terms that included "exosome" and all stroke types. Bibliometric data, including authors, publication years, citations, countries/regions, institutions, journals, and Keywords Plus, were extracted directly from the Web of Science Core Collection. Keywords were mapped using VOSviewer.

RESULTS

From 2010 to 2021, 424 documents were identified with a total of 12,708 citations. The number of publications increased yearly from 2012 to 2021, the majority of which were research and review articles. China and the United States produced the most publications with Henry Ford Hospital and Oakland University serving as the 2 most highly published research institutions. Documents were published most frequently in the journal Stroke. Keywords Plus analyses revealed 3 main research areas: exosomes as pathogenic mediators, biomarkers, and treatments of stroke. Ischemic stroke was the most prevalent type of stroke included in these studies.

CONCLUSIONS

Using bibliometric techniques, this study identified a current and growing interest in the research of exosomes in stroke, particularly in their pathogenic, biomarker, and potential minimally invasive therapeutic properties. Given the high prevalence of ischemic stroke in the current literature, further characterization of exosomes in other stroke types, such as intracerebral hemorrhage, emerges as a future direction for this field of research.

The promise and challenges of extracellular vesicles in the diagnosis of neurodegenerative diseases

Extracellular vesicles (EVs) have emerged as essential means of intercommunication for all cell types, and their role in CNS physiology is increasingly appreciated. Accumulating evidence has demonstrated that EVs play important roles in neural cell maintenance, plasticity, and growth. However, EVs have also been demonstrated to spread amyloids and inflammation characteristic of neurodegenerative disease. Such dual roles suggest that EVs may be prime candidates for neurodegenerative disease biomarker analysis. This is supported by several intrinsic properties of EVs: Populations can be enriched by capturing surface proteins from their cell of origin, their diverse cargo represent the complex intracellular states of the cells they derive from, and they can pass the blood-brain barrier. Despite this promise, there are important questions outstanding in this young field that will need to be answered before it can fulfill its potential. Namely, overcoming the technical challenges of isolating rare EV populations, the difficulties inherent in detecting neurodegeneration, and the ethical considerations of diagnosing asymptomatic individuals. Although daunting, succeeding to answer these questions has the potential to provide unprecedented insight and improved treatment of neurodegenerative disease in the future.

Therapeutic potential of extracellular vesicles in neurodegenerative disorders

Neurodegenerative disorders are characterized by complex multifactorial pathogeneses, thus posing a challenge for standard therapeutic approaches that tend to focus only on one underlying disease aspect. For systemically administered drugs, the blood-brain barrier (BBB) is yet another major obstacle to overcome. In this context, naturally occurring extracellular vesicles (EVs) with intrinsic ability to cross the BBB have been investigated as therapeutics for various diseases, including Alzheimer's and Parkinson's diseases. EVs are cell-derived, lipid membrane-enclosed vesicles carrying a broad spectrum of biologically active molecules, which play a crucial role in intercellular communication. In a therapeutic context, mesenchymal stem cell (MSC)-derived EVs are in the spotlight because they reflect the therapeutic properties of their parental cells and, thus, hold promise as independent cell-free therapeutics. On the other hand, EVs can be used as drug delivery vehicles by modifying their surface or content, e.g., by decorating the surface with brain-specific ligands or loading the EVs with therapeutic RNAs or proteins, thus further enhancing the EV's targeting and therapeutic potency, respectively. Although EVs have been deemed safe for use in humans, some obstacles remain that prevent their progression into clinics. This review scrutinizes the promises and challenges of EV-based treatments for neurodegenerative disorders.

Extracellular vesicles as contributors in the pathogenesis of multiple sclerosis

Extracellular vesicles (EVs) are a heterogeneous family of extracellular structures bounded by a phospholipid bilayer, released by all cell types in various biological fluids, such as blood and cerebrospinal fluid (CSF), playing important roles in intercellular communication, both locally and systemically. EVs carry and deliver a variety of bioactive molecules (proteins, nucleic acids, lipids and metabolites), conferring epigenetic and phenotypic changes to the recipient cells and thus resulting as important mediators of both homeostasis and pathogenesis. In neurological diseases, such as multiple sclerosis (MS), the EV ability to cross Blood-Brain Barrier (BBB), moving from central nervous system (CNS) to the peripheral circulation and vice versa, has increased the interest in EV study in the neurological field. In the present review, we will provide an overview of the recent advances made in understanding the pathogenic role of EVs regarding the immune response, the BBB dysfunction and the CNS inflammatory processes.

Critical Review on the Different Roles of Exosomes in TNBC and Exosomal-Mediated Delivery of microRNA/siRNA/lncRNA and Drug Targeting Signalling Pathways in Triple-Negative Breast Cancer

Triple-negative breast cancer is the most potent metastatic type of breast cancer that can spread to other body parts. Chemotherapy and surgical intervention are the sole treatments for TNBC, owing to the scarcity of therapeutic targets. Manipulation of the membranes as per the desired targets of exosomes has recently gained much attention as a drug delivery method. Despite their known roles in different diseases, very few studies have focused on signalling that triggers the metastasis of triple-negative breast cancer to other body parts by exosomes. This article highlights the significant roles of exosomes associated with TNBC, the involvement of exosomes in breast cancer diagnosis, progression, and the treatment of triple-negative breast cancer by the exosomes as a drug delivery system. This review paper also illustrates the role of exosomes in initiating EMT in breast cancer, including novel signalling.