Extracellular vesicles: Novel promising delivery systems for therapy of brain diseases

The barrier and interface mechanisms of the brain barrier, and brain drug delivery

Three different barriers are formed between the cerebrovascular and the brain parenchyma: the blood-brain barrier (BBB), the blood-cerebrospinal fluid barrier (BCSFB), and the cerebrospinal fluid-brain barrier (CBB). The BBB is the main regulator of blood and central nervous system (CNS) material exchange. The semipermeable nature of the BBB limits the passage of larger molecules and hydrophilic small molecules, Food and Drug Administration (FDA)-approved drugs for the CNS have been generally limited to lipid-soluble small molecules. Although the complexity of the BBB affects CNS drug delivery, understanding the composition and function of the BBB can provide a platform for the development of new methods for CNS drug delivery. This review summarizes the classification of the brain barrier, the composition and role of the basic structures of the BBB, and the transport, barrier, and destruction mechanisms of the BBB; discusses the advantages and disadvantages of different drug delivery methods and prospects for future drug delivery strategies.

Extracellular vesicle therapy for traumatic central nervous system disorders

Traumatic central nervous system (CNS) disorders have catastrophic effects on patients, and, currently, there is no effective clinical treatment. Cell transplantation is a common treatment for traumatic CNS injury in animals. In recent years, an increasing number of studies have reported that the beneficial effect of transplanted cells for CNS repair is mediated primarily through the extracellular vesicles (EVs) secreted by the cells, in which microRNAs play a major role. Accordingly, numerous studies have evaluated the roles and applications of EVs secreted by different cell types in neurological diseases. Furthermore, due to their unique biological features, EVs are used as disease biomarkers and drug delivery systems for disease prevention and treatment. We discuss current knowledge related to EVs, focusing on the mechanism underlying their effects on traumatic CNS diseases, and summarize existing research on the potential clinical utility of EVs as disease biomarkers and drug delivery systems.

Role of Glial Cell-Derived Oxidative Stress in Blood-Brain Barrier Damage after Acute Ischemic Stroke

The integrity of the blood-brain barrier (BBB) is mainly maintained by endothelial cells and basement membrane and could be regulated by pericytes, neurons, and glial cells including astrocytes, microglia, oligodendrocytes (OLs), and oligodendrocyte progenitor cells (OPCs). BBB damage is the main pathological basis of hemorrhage transformation (HT) and vasogenic edema after stroke. In addition, BBB damage-induced HT and vasogenic edema will aggravate the secondary brain tissue damage. Of note, after reperfusion, oxidative stress-initiated cascade plays a critical role in the BBB damage after acute ischemic stroke (AIS). Although endothelial cells are the target of oxidative stress, the role of glial cell-derived oxidative stress in BBB damage after AIS also should receive more attention. In the current review, we first introduce the physiology and pathophysiology of the BBB, then we summarize the possible mechanisms related to BBB damage after AIS. We aim to characterize the role of glial cell-derived oxidative stress in BBB damage after AIS and discuss the role of oxidative stress in astrocytes, microglia cells and oligodendrocytes in after AIS, respectively.

High-efficiency brain-targeted intranasal delivery of BDNF mediated by engineered exosomes to promote remyelination

The regeneration of myelin sheaths is the ultimate goal of the treatment of demyelination disease, including multiple sclerosis (MS). However, current drugs for MS mainly target the immune system and can only slow down the disease development and do not promote the differentiation of oligodendrocyte precursor cells (OPCs) abundant in the myelin injury region into mature oligodendrocytes to form a new myelin sheath. Brain-derived neurotrophic factor (BDNF) plays an important role in the regulation of OPC proliferation and differentiation into mature oligodendrocytes. Exosomes, a kind of nanoscale membrane vesicle secreted by cells, can be used as potential therapeutic drug delivery vectors for central nervous system diseases. Here, brain-targeted modification and BDNF intracellular-loaded exosomes were produced through engineering HEK293T cells, which can promote the differentiation of OPCs into mature oligodendrocytes in vitro. The intranasal administration of the brain-targeted engineered exosome-mediated BDNF was a highly effective delivery route to the brain and had a significant therapeutic effect on remyelination and motor coordination ability improvement in demyelination model mice. The combination of intranasal administration with brain-targeted and BDNF-loaded designed exosomes provides a strategy for efficient drug delivery and treatment of central nervous system diseases.

Nanobiotechnology: A New Frontier for Brain Disorders

Brain disorders, such as neurodegenerative diseases (NDs) and tumors (more than 600 pathologies), are a serious health problem, resulting in brain dysfunctions that limit normal activities, with a significant economic impact [...]

Specific anti-glioma targeted-delivery strategy of engineered small extracellular vesicles dual-functionalised by Angiopep-2 and TAT peptides

Glioma is one of the primary malignant brain tumours in adults, with a poor prognosis. Pharmacological reagents targeting glioma are limited to achieve the desired therapeutic effect due to the presence of blood-brain barrier (BBB). Effectively crossing the BBB and specifically targeting to the brain tumour are the major challenge for the glioma treatments. Here, we demonstrate that the well-defined small extracellular vesicles (sEVs) with dual-targeting drug delivery and cell-penetrating functions, modified by Angiopep-2 and trans-activator of transcription peptides, enable efficient and specific chemotherapy for glioma. The high efficiency of engineered sEVs in targeting BBB and glioma was assessed in both monolayer culture cells and BBB model in vitro, respectively. The observed high targeting efficiency was re-validated in subcutaneous tumour and orthotopic glioma mice models. After loading the doxorubicin into dual-modified functional sEVs, this specific dual-targeting delivery system could cross the BBB, reach the glioma, and penetrate the tumour. Such a mode of drug delivery significantly improved more than 2-fold survival time of glioma mice with very few side effects. In conclusion, utilization of the dual-modified sEVs represents a unique and efficient strategy for drug delivery, holding great promise for the treatments of central nervous system diseases.

Alzheimer's disease: a scoping review of biomarker research and development for effective disease diagnosis

INTRODUCTION

Alzheimer's disease (AD) is regarded as the foremost reason for neurodegeneration that prominently affects the geriatric population. Characterized by extracellular accumulation of amyloid-beta (Aβ), intracellular aggregation of hyperphosphorylated tau (p-tau), and neuronal degeneration that causes impairment of memory and cognition. Amyloid/tau/neurodegeneration (ATN) classification is utilized for research purposes and involves amyloid, tau, and neuronal injury staging through MRI, PET scanning, and CSF protein concentration estimations. CSF sampling is invasive, and MRI and PET scanning requires sophisticated radiological facilities which limit its widespread diagnostic use. ATN classification lacks effectiveness in preclinical AD.

AREAS COVERED

This publication intends to collate and review the existing biomarker profile and the current research and development of a new arsenal of biomarkers for AD pathology from different biological samples, microRNA (miRNA), proteomics, metabolomics, artificial intelligence, and machine learning for AD screening, diagnosis, prognosis, and monitoring of AD treatments.

EXPERT OPINION

It is an accepted observation that AD-related pathological changes occur over a long period of time before the first symptoms are observed providing ample opportunity for detection of biological alterations in various biological samples that can aid in early diagnosis and modify treatment outcomes.

Functionalized Macrophage Exosomes with Panobinostat and PPM1D-siRNA for Diffuse Intrinsic Pontine Gliomas Therapy

Diffuse intrinsic pontine glioma (DIPG) is a rare and fatal pediatric brain tumor. Mutation of p53-induced protein phosphatase 1 (PPM1D) in DIPG cells promotes tumor cell proliferation, and inhibition of PPM1D expression in DIPG cells with PPM1D mutation effectively reduces the proliferation activity of tumor cells. Panobinostat effectively kills DIPG tumor cells, but its systemic toxicity and low blood-brain barrier (BBB) permeability limits its application. In this paper, a nano drug delivery system based on functionalized macrophage exosomes with panobinostat and PPM1D-siRNA for targeted therapy of DIPG with PPM1D mutation is prepared. The nano drug delivery system has higher drug delivery efficiency and better therapeutic effect than free drugs. In vivo and in vitro experimental results show that the nano drug delivery system can deliver panobinostat and siRNA across the BBB and achieve a targeted killing effect of DIPG tumor cells, resulting in the prolonged survival of orthotopic DIPG mice. This study provides new ideas for the delivery of small molecule drugs and gene drugs for DIPG therapy.

Can the administration of platelet lysates to the brain help treat neurological disorders?

Neurodegenerative disorders of the central nervous system (CNS) and brain traumatic insults are characterized by complex overlapping pathophysiological alterations encompassing neuroinflammation, alterations of synaptic functions, oxidative stress, and progressive neurodegeneration that eventually lead to irreversible motor and cognitive dysfunctions. A single pharmacological approach is unlikely to provide a complementary set of molecular therapeutic actions suitable to resolve these complex pathologies. Recent preclinical data are providing evidence-based scientific rationales to support biotherapies based on administering neurotrophic factors and extracellular vesicles present in the lysates of human platelets collected from healthy donors to the brain. Here, we present the most recent findings on the composition of the platelet proteome that can activate complementary signaling pathways in vivo to trigger neuroprotection, synapse protection, anti-inflammation, antioxidation, and neurorestoration. We also report experimental data where the administration of human platelet lysates (HPL) was safe and resulted in beneficial neuroprotective effects in established rodent models of neurodegenerative diseases such as Parkinson's disease, Alzheimer's disease, traumatic brain injury, and stroke. Platelet-based biotherapies, prepared from collected platelet concentrates (PC), are emerging as a novel pragmatic and accessible translational therapeutic strategy for treating neurological diseases. Based on this assumption, we further elaborated on various clinical, manufacturing, and regulatory issues that need to be addressed to ensure the ethical supply, quality, and safety of HPL preparations for treating neurodegenerative and traumatic pathologies of the CNS. HPL made from PC may become a unique approach for scientifically based treatments of neurological disorders readily accessible in low-, middle-, and high-income countries.

Nanomedicine for Glioblastoma: Progress and Future Prospects

Glioblastoma is the most aggressive form of brain tumor, accounting for the highest mortality and morbidity rates. Current treatment for patients with glioblastoma includes maximal safe tumor resection followed by radiation therapy with concomitant temozolomide (TMZ) chemotherapy. The addition of TMZ to the conformal radiation therapy has improved the median survival time only from 12 months to 16 months in patients with glioblastoma. Despite these aggressive treatment strategies, patients' prognosis remains poor. This therapeutic failure is primarily attributed to the blood-brain barrier (BBB) that restricts the transport of TMZ from reaching the tumor site. In recent years, nanomedicine has gained considerable attention among researchers and shown promising developments in clinical applications, including the diagnosis, prognosis, and treatment of glioblastoma tumors. This review sheds light on the morphological and physiological complexity of the BBB. It also explains the development of nanomedicine strategies to enhance the permeability of drug molecules across the BBB.

Recent progresses in exosome-based systems for targeted drug delivery to the brain

Despite the multiple ongoing and novel initiatives for developing brain-targeted drug delivery systems, insurmountable obstacles remain. A perfect drug delivery device that can bypass the brain-blood barrier and boost therapeutic efficacy is urgently needed for clinical applications. Exosomes hold unrivaled benefits as a drug delivery vehicle for treating brain diseases due to their endogenous and innate attributes. Unique properties, such as the ability to penetrate physical barriers, biocompatibility, innate targeting features, ability to leverage natural intracellular trafficking pathways, favored tumor homing, and stability, make exosomes suitable for brain-targeted drug delivery. Herein, we provide an overview of recent exosome-based drug delivery nanoplatforms and discuss how these inherent vesicles can be used to deliver therapeutic agents to the brain to cure neurodegenerative diseases, brain tumors, and other brain disorders. Moreover, we review the current roadblocks associated with exosomes and other brain-targeted drug delivery systems and discuss future directions for achieving successful therapy outcomes.

Different Sourced Extracellular Vesicles and Their Potential Applications in Clinical Treatments

Extracellular vesicles (EVs) include a heterogeneous group of natural cell-derived nanostructures that are increasingly regarded as promising biotherapeutic agents and drug delivery vehicles in human medicine. Desirable intrinsic properties of EVs including the ability to bypass natural membranous barriers and to deliver their unique biomolecular cargo to specific cell populations position them as fiercely competitive alternatives for currently available cell therapies and artificial drug delivery platforms. EVs with distinct characteristics can be released from various cell types into the extracellular environment as a means of transmitting bioactive components and altering the status of the target cell. Despite the existence of a large number of preclinical studies confirming the therapeutic efficacy of different originated EVs for treating several pathological conditions, in this review, we first provide a brief overview of EV biophysical properties with an emphasis on their intrinsic therapeutic benefits over cell-based therapies and synthetic delivery systems. Next, we describe in detail different EVs derived from distinct cell sources, compare their advantages and disadvantages, and recapitulate their therapeutic effects on various human disorders to highlight the progress made in harnessing EVs for clinical applications. Finally, knowledge gaps and concrete hurdles that currently hinder the clinical translation of EV therapies are debated with a futuristic perspective.

Exosomes in the Field of Neuroscience: A Scientometric Study and Visualization Analysis

Exosomes have received great attention for their diagnostic, therapeutic, and prognostic roles in the field of neuroscience over the past decade. This scientometric study aimed to quantitatively and qualitatively evaluate knowledge structure, hot topics, and research trends of studies about exosomes in the field of neuroscience using visualization tools. Web of Science Core collection databases were searched for relevant publications between 2005 and 2021. The Carrot2 online system, BICOMB, gCLUTO, and Ucinet software were utilized for key word analysis, and co-citations analyses were conducted in Citespace and VOSviewer. Altogether, 21 high-frequency key words were collected from 856 included articles, and 5 clusters were identified through biclustering analyses. The strategic diagram and social network analysis further determined research hotspots and trends. Co-citation analysis results revealed a few crucial works that contributed to the development of research on exosomes in the field of neuroscience. Moreover, the important sources that had contributed to the development of this field were identified. Our findings suggested that Alzheimer's disease-related research remained a hot topic in this field till now, and recent researchers had extended their scopes to more cognitive impairments. Importantly, researches related to exosomes in multiple sclerosis and Parkinson's disease were promising. While exosomes in acute central nervous system injury had not been sufficiently investigated, with continuous improvement in exosome-based delivery technology, this subject might make a breakthrough in terms of therapeutic innovations in the immediate future.

Synchronous Disintegration of Ferroptosis Defense Axis via Engineered Exosome-Conjugated Magnetic Nanoparticles for Glioblastoma Therapy

Glioblastoma (GBM) is one of the most fatal central nervous system tumors and lacks effective or sufficient therapies. Ferroptosis is a newly discovered method of programmed cell death and opens a new direction for GBM treatment. However, poor blood-brain barrier (BBB) penetration, reduced tumor targeting ability, and potential compensatory mechanisms hinder the effectiveness of ferroptosis agents during GBM treatment. Here, a novel composite therapeutic platform combining the magnetic targeting features and drug delivery properties of magnetic nanoparticles with the BBB penetration abilities and siRNA encapsulation properties of engineered exosomes for GBM therapy is presented. This platform can be enriched in the brain under local magnetic localization and angiopep-2 peptide-modified engineered exosomes can trigger transcytosis, allowing the particles to cross the BBB and target GBM cells by recognizing the LRP-1 receptor. Synergistic ferroptosis therapy of GBM is achieved by the combined triple actions of the disintegration of dihydroorotate dehydrogenase and the glutathione peroxidase 4 ferroptosis defense axis with Fe₃ O₄ nanoparticle-mediated Fe²⁺ release. Thus, the present findings show that this system can serve as a promising platform for the treatment of glioblastoma.

Different Effects of RNAi-Mediated Downregulation or Chemical Inhibition of NAMPT in an Isogenic IDH Mutant and Wild-Type Glioma Cell Model

The IDH1^R132H mutation in glioma results in the neoenzymatic function of IDH1, leading to the production of the oncometabolite 2-hydroxyglutarate (2-HG), alterations in energy metabolism and changes in the cellular redox household. Although shifts in the redox ratio NADPH/NADP⁺ were described, the consequences for the NAD⁺ synthesis pathways and potential therapeutic interventions were largely unexplored. Here, we describe the effects of heterozygous IDH1^R132H on the redox system in a CRISPR/Cas edited glioblastoma model and compare them with IDH1 wild-type (IDH1^wt) cells. Besides an increase in 2-HG and decrease in NADPH, we observed an increase in NAD⁺ in IDH1^R132H glioblastoma cells. RT-qPCR analysis revealed the upregulation of the expression of the NAD⁺ synthesis enzyme nicotinamide phosphoribosyltransferase (NAMPT). Knockdown of NAMPT resulted in significantly reduced viability in IDH1^R132H glioblastoma cells. Given this dependence of IDH1^R132H cells on NAMPT expression, we explored the effects of the NAMPT inhibitors FK866, GMX1778 and GNE-617. Surprisingly, these agents were equally cytotoxic to IDH1^R132H and IDH1^wt cells. Altogether, our results indicate that targeting the NAD⁺ synthesis pathway is a promising therapeutic strategy in IDH mutant gliomas; however, the agent should be carefully considered since three small-molecule inhibitors of NAMPT tested in this study were not suitable for this purpose.

Exogenous loading of extracellular vesicles, virus-like particles, and lentiviral vectors with supercharged proteins

Cell membrane-based biovesicles (BVs) are important candidate drug delivery vehicles and comprise extracellular vesicles, virus-like particles, and lentiviral vectors. Here, we introduce a non-enzymatic assembly of purified BVs, supercharged proteins, and plasmid DNA called pDNA-scBVs. This multicomponent vehicle results from the interaction of negative sugar moieties on BVs and supercharged proteins that contain positively charged amino acids on their surface to enhance their affinity for pDNA. pDNA-scBVs were demonstrated to mediate floxed reporter activation in culture by delivering a Cre transgene. We introduced pDNA-scBVs containing both a CRE-encoding plasmid and a BV-packaged floxed reporter into the brains of Ai9 mice. Successful delivery of both payloads by pDNA-scBVs was confirmed with reporter signal in the striatal brain region. Overall, we developed a more efficient method to load isolated BVs with cargo that functionally modified recipient cells. Augmenting the natural properties of BVs opens avenues for adoptive extracellular interventions using therapeutic loaded cargo.

Exosome Mediated Cytosolic Cisplatin Delivery Through Clathrin-Independent Endocytosis and Enhanced Anti-cancer Effect via Avoiding Endosome Trapping in Cisplatin-Resistant Ovarian Cancer

Background

Ovarian carcinoma is one of the most common gynecologic malignancies, cisplatin resistance has become a key obstacle to the successful treatment of ovarian cancer because ovarian carcinomas are liable to drug resistance. To find an effective drug carrier is an urgent need.

Methods

Exosomes and loading-cisplatin exosomes are isolated using differential centrifugation and characterized by transmission, electron, nanoparticle tracking analysis. The anti-cancer effect of cisplatin was detected under the circumstance of delivered by exosomes or without exosomes in vitro and in vivo. Using proteome analysis and bioinformatics analysis, we further discovered the pathways in exosomes delivery process. We employed a con-focal immunofluorescence analysis, to evaluate the effects of milk-exosomes deliver the cisplatin via avoiding endosomal trapping.

Results

Exosomes and exosome-cisplatin were characterized including size, typical markers including CD63, Alix and Tsg101. The anti-cancer effect of cisplatin was enhanced when delivered by exosome in vitro and in vivo. Mechanistic studies shown that exosomes deliver cisplatin mostly via clathrin-independent endocytosis pathway. Exosomes deliver cisplatin into cisplatin-resistant cancer cells clathrin-independent endocytosis and enhance the anti-cancer effect through avoiding endosome trapping.

Conclusion

Cisplatin could be delivered by exosome through clathrin-independent endocytosis, and could evade the endosome trapping, diffused in the cytosol evenly. Our study clarifies the mechanism of exosomes mediated drug delivery against resistant cancer, indicates that exosomes can be a potential nano-carrier for cisplatin against cisplatin resistant ovarian cancer, which validates and enriches the theory of intracellular exosome trafficking.

Microglia Polarization: A Novel Target of Exosome for Stroke Treatment

The vast majority of cells in the human body are capable of secreting exosomes. Exosomes have become an important vehicle for signaling between cells. Exosomes secreted by different cells have some of the structural and functional properties of that cell and thus have different regulatory functions. A large number of recent experimental studies have shown that exosomes from different sources have different regulatory effects on stroke, and the mechanisms still need to be elucidated. Microglia are core members of central intrinsic immune regulatory cells, which play an important regulatory role in the pathogenesis and progression of stroke. M1 microglia cause neuroinflammation and induce neurotoxic effects, while M2 microglia inhibit neuroinflammation and promote neurogenesis, thus exerting a series of neuroprotective effects. It was found that there is a close link between exosomes and microglia polarization, and that exosome inclusions such as microRNAs play a regulatory role in the M1/M2 polarization of microglia. This research reviews the role of exosomes in the regulation of microglia polarization and reveals their potential value in stroke treatment.

Targeted Anti-Hepatocellular Carcinoma Research of Targeted Peptides Combined with Drug-Loaded Cell-Derived Microparticles

To conduct an anti-tumor research by using targeted drug-loaded cell-derived microparticles to target the tumor microenvironment and enhance NK cell killing function. In this experiment, we obtained HepG2 tumor cell-derived microparticles by physical extrusion, high speed centrifugation and filtration, modified the hepatocellular carcinoma targeting peptide SP94 on the surface of microparticles and encapsulated the TGF-β inhibitor SB505124. Finally we validated and analyzed whether the new drug delivery system can target to tumor site and enhance the anti-tumor function of NK cells. This type of novel targeted cell-derived microparticles drug delivery system will provide a novel idea for tumor immunotherapy.

Lipid-Based Nano-Sized Cargos as a Promising Strategy in Bone Complications: A Review

Bone metastasis has been considered the fatal phase of cancers, which remains incurable and to be a challenge due to the non-availability of the ideal treatment strategy. Unlike bone cancer, bone metastasis involves the spreading of the tumor cells to the bones from different origins. Bone metastasis generally originates from breast and prostate cancers. The possibility of bone metastasis is highly attributable to its physiological milieu susceptible to tumor growth. The treatment of bone-related diseases has multiple complications, including bone breakage, reduced quality of life, spinal cord or nerve compression, and pain. However, anticancer active agents have failed to maintain desired therapeutic concentrations at the target site; hence, uptake of the drug takes place at a non-target site responsible for the toxicity at the cellular level. Interestingly, lipid-based drug delivery systems have become the center of interest for researchers, thanks to their biocompatible and bio-mimetic nature. These systems possess a great potential to improve precise bone targeting without affecting healthy tissues. The lipid nano-sized systems are not only limited to delivering active agents but also genes/peptide sequences/siRNA, bisphosphonates, etc. Additionally, lipid coating of inorganic nanomaterials such as calcium phosphate is an effective approach against uncontrollable rapid precipitation resulting in reduced colloidal stability and dispersity. This review summarizes the numerous aspects, including development, design, possible applications, challenges, and future perspective of lipid nano-transporters, namely liposomes, exosomes, solid lipid nanoparticles (SLN), nanostructured lipid carriers (NLC), and lipid nanoparticulate gels to treat bone metastasis and induce bone regeneration. Additionally, the economic suitability of these systems has been discussed and different alternatives have been discussed. All in all, through this review we will try to understand how far nanomedicine is from clinical and industrial applications in bone metastasis.

The advances in nanomedicine for bone and cartilage repair

With the gradual demographic shift toward an aging and obese society, an increasing number of patients are suffering from bone and cartilage injuries. However, conventional therapies are hindered by the defects of materials, failing to adequately stimulate the necessary cellular response to promote sufficient cartilage regeneration, bone remodeling and osseointegration. In recent years, the rapid development of nanomedicine has initiated a revolution in orthopedics, especially in tissue engineering and regenerative medicine, due to their capacity to effectively stimulate cellular responses on a nanoscale with enhanced drug loading efficiency, targeted capability, increased mechanical properties and improved uptake rate, resulting in an improved therapeutic effect. Therefore, a comprehensive review of advancements in nanomedicine for bone and cartilage diseases is timely and beneficial. This review firstly summarized the wide range of existing nanotechnology applications in the medical field. The progressive development of nano delivery systems in nanomedicine, including nanoparticles and biomimetic techniques, which are lacking in the current literature, is further described. More importantly, we also highlighted the research advancements of nanomedicine in bone and cartilage repair using the latest preclinical and clinical examples, and further discussed the research directions of nano-therapies in future clinical practice.

Exploration and functionalization of M1-macrophage extracellular vesicles for effective accumulation in glioblastoma and strong synergistic therapeutic effects

Glioblastoma multiforme (GBM) is a highly aggressive brain tumor with an extremely low survival rate. New and effective approaches for treatment are therefore urgently needed. Here, we successfully developed M1-like macrophage-derived extracellular vesicles (M1EVs) that overcome multiple challenges via guidance from two macrophage-related observations in clinical specimens from GBM patients: enrichment of M2 macrophages in GBM; and origination of a majority of infiltrating macrophage from peripheral blood. To maximize the synergistic effect, we further functionalized the membranes of M1EVs with two hydrophobic agents (the chemical excitation source CPPO (C) and the photosensitizer Ce6 (C)) and loaded the hydrophilic hypoxia-activated prodrug AQ4N (A) into the inner core of the M1EVs. After intravenous injection, the inherent nature of M1-derived extracellular vesicles CCA-M1EVs allowed for blood-brain barrier penetration, and modulated the immunosuppressive tumor microenvironment via M2-to-M1 polarization, which increased hydrogen peroxide (H₂O₂) levels. Furthermore, the reaction between H₂O₂ and CPPO produced chemical energy, which could be used for Ce6 activation to generate large amounts of reactive oxygen species to achieve chemiexcited photodynamic therapy (CDT). As this reaction consumed oxygen, the aggravation of tumor hypoxia also led to the conversion of non-toxic AQ4N into toxic AQ4 for chemotherapy. Therefore, CCA-M1EVs achieved synergistic immunomodulation, CDT, and hypoxia-activated chemotherapy in GBM to exert a potent therapeutic effect. Finally, we demonstrated the excellent effect of CCA-M1EVs against GBM in cell-derived xenograft and patient-derived xenograft models, underscoring the strong potential of our highly flexible M1EVs system to support multi-modal therapies for difficult-to-treat GBM.

Microfluidic platforms for extracellular vesicle isolation, analysis and therapy in cancer

Extracellular vesicles (EVs) are small lipidic particles packed with proteins, DNA, messenger RNA and microRNAs of their cell of origin that act as critical players in cell-cell communication. These vesicles have been identified as pivotal mediators in cancer progression and the formation of metastatic niches. Hence, their isolation and analysis from circulating biofluids is envisioned as the next big thing in the field of liquid biopsies for early non-invasive diagnosis and patient follow-up. Despite the promise, current benchtop isolation strategies are not compatible with point-of-care testing in a clinical setting. Microfluidic platforms are disruptive technologies capable of recovering, analyzing, and quantifying EVs within clinical samples with limited volume, in a high-throughput manner with elevated sensitivity and multiplexing capabilities. Moreover, they can also be employed for the controlled production of synthetic EVs and effective drug loading to produce EV-based therapies. In this review, we explore the use of microfluidic platforms for the isolation, characterization, and quantification of EVs in cancer, and compare these platforms with the conventional methodologies. We also highlight the state-of-the-art in microfluidic approaches for EV-based cancer therapeutics. Finally, we analyze the currently active or recently completed clinical trials involving EVs for cancer diagnosis, treatment or therapy monitoring and examine the future of EV-based point-of-care testing platforms in the clinic and EV-based therapy production by the industry.

Engineered extracellular vesicles: potentials in cancer combination therapy

Extracellular vesicles (EVs) are a group of secretory vesicles with cell-derived membrane and contents. Due to the cargo delivery capability, EVs can be designed as drug delivery platforms for cancer therapy. Biocompatibility and immune compatibility endow EVs with unique advantages compared with other nanocarriers. With the development of this field, multiple ingenious modification methods have been developed to obtain engineered EVs with desired performance. Application of engineered EVs in cancer therapy has gradually shifted from monotherapy to combinational therapy to fight against heterogeneous cancer cells and complex tumor microenvironment. In addition, the strong plasticity and load capacity of engineered EV make it potential to achieve various combinations of cancer treatment methods. In this review, we summarize the existing schemes of cancer combination therapy realized by engineered EVs, highlight the mechanisms and representative examples of these schemes and provide guidance for the future application of engineered EVs to design more effective cancer combination treatment plans.

Research Progress on the Inflammatory Effects of Long Non-coding RNA in Traumatic Brain Injury

Globally, traumatic brain injury (TBI) is an acute clinical event and an important cause of death and long-term disability. However, the underlying mechanism of the pathophysiological has not been fully elucidated and the lack of effective treatment a huge burden to individuals, families, and society. Several studies have shown that long non-coding RNAs (lncRNAs) might play a crucial role in TBI; they are abundant in the central nervous system (CNS) and participate in a variety of pathophysiological processes, including oxidative stress, inflammation, apoptosis, blood-brain barrier protection, angiogenesis, and neurogenesis. Some lncRNAs modulate multiple therapeutic targets after TBI, including inflammation, thus, these lncRNAs have tremendous therapeutic potential for TBI, as they are promising biomarkers for TBI diagnosis, treatment, and prognosis prediction. This review discusses the differential expression of different lncRNAs in brain tissue during TBI, which is likely related to the physiological and pathological processes involved in TBI. These findings may provide new targets for further scientific research on the molecular mechanisms of TBI and potential therapeutic interventions.

The combination of autologous mesenchymal stem cell-derived exosomes and neurotrophic factors as an intervention for amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis is a chronic progressive degeneration of motor neurons and has a high mortality. Riluzole and edaravone are the only approved medications currently being used for amyotrophic lateral sclerosis in clinical settings. However, they can lead to serious complications, such as injuries to the liver and kidney. To date, there is no effective treatment for amyotrophic lateral sclerosis. In this regard, investigations concerning the employment of exosomes, mesenchymal stem cells, and neurotrophic factors to ameliorate amyotrophic lateral sclerosis are attracting considerable attention in the scientific community. Herein, we systematically analyze the relationship relevant to autologous mesenchymal stem cell derived-exosomes, neurotrophic factors and amyotrophic lateral sclerosis. Mesenchymal stem cells modulate immune response, mitigate oxidative stress, promote neuronal regeneration, and differentiate into neuronal and glial cells. Furthermore, exosomes from mesenchymal stem cells exert beneficial effects on their mother cells by preventing abnormal differentiation of mesenchymal stem cells. Similarly, neurotrophic factors regulate inflammatory response, stimulate the neuron repair, and the recovery of neuronal functioning. Therefore, autologous mesenchymal stem cells-derived exosomes combined with neurotrophic factors could potentially be an effective interventional medium for amyotrophic lateral sclerosis.

Mesenchymal Stem Cell-Derived Extracellular Vesicles in Liver Immunity and Therapy

Mesenchymal stem cells (MSCs), as the most common cell source for stem cell therapy, play an important role in the modulation of innate and adaptive immune responses and have been widely used in clinical trials to treat autoimmune and inflammatory diseases. Recent experimental and clinical studies have shown that MSC-derived extracellular vesicles (MSC-EVs) can inhibit the activation and proliferation of a variety of proinflammatory cells, such as Th1, Th17 and M1 macrophages, reducing the secretion of proinflammatory cytokines, while promoting the proliferation of anti-inflammatory cells, such as M2 macrophages and Tregs, and increasing the secretion of anti-inflammatory cytokines, thus playing a role in immune regulation and exhibiting immunomodulatory functions. Besides MSC-EVs are more convenient and less immunogenic than MSCs. There is growing interest in the role of MSC-EVs in liver diseases owing to the intrinsic liver tropism of MSC-EVs. In this review, we focus on the immunomodulatory effects of MSC-EVs and summarize the pivotal roles of MSC-EVs as a cell-free therapy in liver diseases, including NAFLD, AIH, acute liver failure, liver fibrosis and hepatic ischemia–reperfusion injury. Moreover, we provide a concise overview of the potential use and limits of MSC-EVs in clinical application.

Role of brain extracellular vesicles in air pollution-related cognitive impairment and neurodegeneration

A relationship between environmental exposure to air pollution and cognitive impairment and neurological disorders has been described. Previous literature has focused on the direct effects of the air pollution components on neuronal and glial cells, as well as on involvement of oxidative stress and neuroinflammation on microglia and astrocyte reactivity. However, other mechanisms involved in the air pollution effects on central nervous system (CNS) toxicity can be playing critical roles. Increasingly, extracellular vesicle's (EVs) mediated intercellular communication is being recognized as impacting the development of cognitive impairment and neurological disorders like Alzheimer's disease and others. Here we describe the available evidence about toxic air pollutants and its components on brain, an involvement of brain cells specific and EVs types (based in the origin or in the size of EVs) in the initiation, exacerbation, and propagation of the neurotoxic effects (inflammation, neurodegeneration, and accumulation of neurotoxic proteins) induced by air pollution in the CNS. Additionally, we discuss the identification and isolation of neural-derived EVs from human plasma, the most common markers for neural-derived EVs, and their potential for use as diagnostic or therapeutic molecules for air pollution-related cognitive impairment and neurodegeneration.

Gather wisdom to overcome barriers: Well-designed nano-drug delivery systems for treating gliomas

Due to the special physiological and pathological characteristics of gliomas, most therapeutic drugs are prevented from entering the brain. To improve the poor prognosis of existing therapies, researchers have been continuously developing non-invasive methods to overcome barriers to gliomas therapy. Although these strategies can be used clinically to overcome the blood‒brain barrier (BBB), the accurate delivery of drugs to the glioma lesions cannot be ensured. Nano-drug delivery systems (NDDS) have been widely used for precise drug delivery. In recent years, researchers have gathered their wisdom to overcome barriers, so many well-designed NDDS have performed prominently in preclinical studies. These meticulous designs mainly include cascade passing through BBB and targeting to glioma lesions, drug release in response to the glioma microenvironment, biomimetic delivery systems based on endogenous cells/extracellular vesicles/protein, and carriers created according to the active ingredients of traditional Chinese medicines. We reviewed these well-designed NDDS in detail. Furthermore, we discussed the current ongoing and completed clinical trials of NDDS for gliomas therapy, and analyzed the challenges and trends faced by clinical translation of these well-designed NDDS.

Chemical Advances in Therapeutic Application of Exosomes and Liposomes

Exosomes and liposomes are vesicular nanoparticles that can encapsulate functional cargo. The chemical similarities between naturally occurring exosomes and synthetic liposomes have accelerated the development of exosome mimetics as a therapeutic drug delivery platform under physiological and pathological environments. To maximise the applications of exosomes and liposomes in the clinical setting, it is essential to look into their basic chemical properties and utilise these characteristics to optimise the preparation, loading, modification and hybridisation. This review summarises the chemical and biological properties of both exosomal and liposomal systems as well as some of the challenges related to their production and application. This article concludes with a discussion on potential perspectives for the integration of exosomal and liposomal technologies in mapping better approaches for their biomedical use, especially in therapeutics.

Role of exosomes in the pathogenesis of inflammation in Parkinson's disease

Inflammatory responses, including glial cell activation and peripheral immune cell infiltration, are involved in the pathogenesis of Parkinson’s disease (PD). These inflammatory responses appear to be closely related to the release of extracellular vesicles, such as exosomes. However, the relationships among different forms of glial cell activation, synuclein dysregulation, mitochondrial dysfunction, and exosomes are complicated. This review discusses the multiple roles played by exosomes in PD-associated inflammation and concludes that exosomes can transport toxic α-synuclein oligomers to immature neurons and into the extracellular environment, inducing the oligomerization of α-synuclein in normal neurons. Misfolded α-synuclein causes microglia and astrocytes to activate and secrete exosomes. Glial cell-derived exosomes participate in communications between glial cells and neurons, triggering anti-stress and anti-inflammatory responses, in addition to axon growth. The production and release of mitochondrial vesicles and exosomes establish a new mechanism for linking mitochondrial dysfunction to systemic inflammation associated with PD. Given the relevance of exosomes as mediators of neuron-glia communication in neuroinflammation and neuropathogenesis, new targeted treatment strategies are currently being developed that use these types of extracellular vesicles as drug carriers. Exosome-mediated inflammation may be a promising target for intervention in PD patients.

Engineered extracellular vesicles encapsulated Bryostatin-1 as therapy for neuroinflammation

Targeted and effective drug delivery to central nervous system (CNS) lesions is a major challenge in the treatment of multiple sclerosis (MS). Extracellular vesicles (EVs) have great promise as a drug delivery nanosystem given their unique characteristics, including a strong cargo-loading capacity, low immunogenicity, high biocompatibility, inherent stability, high delivery efficiency, ease of manipulation, and blood-brain barrier (BBB) penetration. Clinical applications are, however, limited by their insufficient targeting capability and "dilution effects" upon systemic administration. Neural stem cells (NSCs) provide an abundant source of EVs because of their remarkable capacity for self-renewal. Here, we developed a novel therapeutic strategy for local delivery and treatment using EVPs, which are derived from NSCs with the expression of the CNS lesion targeting ligand-PDGFRα. Furthermore, we used EVPs as a targeting carrier for encapsulating Bryostatin-1 (Bryo-1), a natural compound with remarkable anti-inflammation ability. Our data showed that Bryo-1 delivered by EVPs was more stable and concentrated in the CNS than native Bryo-1. Systemic injection of a low dosage (1 × 10⁸ particles) of EVPs + Bryo-1, versus only EVPs or Bryo-1 administration, significantly ameliorated clinical disease development, decreased the infiltration of pro-inflammatory cells, blocked myelin loss and astrogliosis, protected BBB integrity, and altered microglia pro-inflammatory phenotype in the CNS of EAE mice. Taken as a whole, our study showed that engineered EVs have a CNS targeting capacity, and it provides potentially powerful therapeutic effects for the treatment of various neuroinflammatory diseases.

Exosomes and their Cargo as a New Avenue for Brain and Treatment of CNS-Related Diseases

Extracellular Vesicles (EVs), which belong to nanoscale vesicles, including microvesicles (MVs) and exosomes, are now considered a new important tool for intercellular neuronal communication in the Central Nervous System (CNS) under physiological and pathological conditions. EVs are shed into blood, peripheral body fluids and cerebrospinal fluid (CSF) by a large variety of cells.

EVs can act locally on neighboring and distant cells. EVs represent the fingerprints of the originating cells and can carry a variety of molecular constituents of their cell of origin, including protein, lipids, DNA and microRNAs (miRNAs).

The most studied EVs are the exosomes because they are ubiquitous and have the capacity to transfer cell-derived components and bioactive molecules to target cells. In this minireview, we focused on cell-cell communication in CNS mediated by exosomes and their important cargo as an innovative way to treat or follow up with CNS diseases.

Stem cell-derived extracellular vesicle therapy for acute brain insults and neurodegenerative diseases

Stem cell-based therapy is a promising approach for treating a variety of disorders, including acute brain insults and neurodegenerative diseases. Stem cells such as mesenchymal stem cells (MSCs) secrete extracellular vesicles (EVs), circular membrane fragments (30 nm−1 μm) that are shed from the cell surface, carrying several therapeutic molecules such as proteins and microRNAs. Because EV-based therapy is superior to cell therapy in terms of scalable production, biodistribution, and safety profiles, it can be used to treat brain diseases as an alternative to stem cell therapy. This review presents evidences evaluating the role of stem cell-derived EVs in stroke, traumatic brain injury, and degenerative brain diseases, such as Alzheimer’s disease and Parkinson’ disease. In addition, stem cell-derived EVs have better profiles in biocompatibility, immunogenicity, and safety than those of small chemical and macromolecules. The advantages and disadvantages of EVs compared with other strategies are discussed. Even though EVs obtained from native stem cells have potential in the treatment of brain diseases, the successful clinical application is limited by the short half-life, limited targeting, rapid clearance after application, and insufficient payload. We discuss the strategies to enhance the efficacy of EV therapeutics. Finally, EV therapies have yet to be approved by the regulatory authorities. Major issues are discussed together with relevant advances in the clinical application of EV therapeutics.

Nanocarrier mediated drug delivery as an impeccable therapeutic approach against Alzheimer's disease

For the past several years, dementia, is one of the predominantly observed groups of symptoms in a geriatric population. Alzheimer's disease (AD) is a progressive memory related neurodegenerative disease, for which the current Food and drug administration approved therapeutics are only meant for a symptomatic management rather than targeting the root cause of AD. These therapeutics belong to two classes, Acetylcholine Esterase inhibitors and N-methyl D-aspartate antagonist. Furthermore, to facilitate neuroprotective action in AD, the drugs are majorly expected to reach the specific target area in the brain for the desired efficacy. Thus, there is a huge requirement for drug discovery and development for facilitating the entry of drugs more in brain to exert a specific action. The very first line of defense and the major limitation for the entry of drugs into the brain is the Blood Brain Barrier, followed by Blood-Cerebrospinal Fluid Barrier. More than a barrier, these mainly act as selectively permeable membranes, which allows entry of specific molecules into the brain. Furthermore, specific enzymes result in the degradation of xenobiotics. All these mechanisms pose as hurdles in the way of effective drug delivery in the brain. Thus, novel techniques need to be harbored for the facilitation of the delivery of such drugs into the brain. Nanocarriers are advantageous for facilitating the specific targeted drug treatment in AD. As nanomedicines are one of the novels and most useful approaches for AD, thus the present review mainly focuses on understanding the advanced use of nanocarriers for targeted drug delivery in the management of AD.

The Role of Exosomal Non-Coding RNAs in Colorectal Cancer Drug Resistance

Background: Colorectal cancer (CRC) is one of the most common types of cancer diagnosed worldwide with high morbidity; drug resistance is often responsible for treatment failure in CRC. Non-coding RNAs (ncRNAs) play distinct regulatory roles in tumorigenesis, cancer progression and chemoresistance. Methods: A literature search was conducted in PubMed database in order to sum up and discuss the role of exosomal ncRNAs (ex-ncRNAs) in CRC drug resistance/response and their possible mechanisms. Results: Thirty-six (36) original research articles were identified; these included exosome or extracellular vesicle (EV)-containing microRNAs (miRNAs), long non-coding RNAs (lncRNAs), circular RNAs (circRNAs) and small-interfering (siRNAs). No studies were found for piwi-interacting RNAs. Conclusions: Exosomal transfer of ncRNAs has been documented as a new mechanism of CRC drug resistance. Despite being in its infancy, it has emerged as a promising field for research in order to (i) discover novel biomarkers for therapy monitoring and/or (ii) reverse drug desensitization.

An efficient and safe MUC1-dendritic cell-derived exosome conjugate vaccine elicits potent cellular and humoral immunity and tumor inhibition in vivo

Antitumor vaccines are a promising strategy for preventing or treating cancers by eliciting antitumor immune responses and inducing protective immunity against specific antigens expressed on tumor cells. Vaccine formulations that enhance the humoral and cellular immune responses of vaccine candidates would be highly beneficial but are still limited. Here we developed an antitumor vaccine candidate by conjugating a MUC1 glycopeptide antigen to dendritic cell-derived exosomes (Dex). In vivo, the MUC1-Dex construct induced high MUC1-specific IgG antibody titers with strong binding affinities for MUC1-positive tumor cells and promoted cytokine secretion. Moreover, CD8⁺ T cells from immunized mice exhibited strong cytotoxicity against MUC1-positive tumor cells. Importantly, in both preventative and therapeutic tumor-bearing mouse models, the construct inhibited tumor growth and prolonged survival. Collectively, these results demonstrate that Dex is a promising vaccine carrier that can be used as adjuvant to enhance the immunological efficacy of tumor vaccines. STATEMENT OF SIGNIFICANCE.

Exosomal-long non-coding RNAs journey in colorectal cancer: Evil and goodness faces of key players

Exosomes are nano-vesicles (NVs) secreted by cells and take part in cell-cell communications. Lately, these exosomes were proved to have dual faces in cancer. Actually, they can contribute to carcinogenesis through epithelial-mesenchymal transition (EMT), angiogenesis, metastasis and tumor microenvironment (TME) of various cancers, including colorectal cancer (CRC). On the other hand, they can be potential targets for cancer treatment. CRC is one of the most frequent tumors worldwide, with incidence rates rising in the recent decades. In its early stage, CRC is asymptomatic with poor treatment outcomes. Therefore, finding a non-invasive, early diagnostic biomarker tool and/or suitable defender to combat CRC is mandatory. Exosomes provide enrichment and safe setting for their cargos non-coding RNAs (ncRNAs) and proteins, whose expression levels can be upregulated ordown-regulated in cancer. Hence, exosomes can be used as diagnostic and/or prognostic tools for cancer. Moreover, exosomes can provide a novel potential therapeutic modality for tumors via loading with specific chemotherapeutic agents, with the advantage of possible tumor targeting. In this review, we will try to collect and address recent studies concerned with exosomes and their cargos' implications for CRC diagnosis and/or hopefully, treatment.

Using genetically modified extracellular vesicles as a non-invasive strategy to evaluate brain-specific cargo

The lack of techniques to trace brain cell behavior in vivo hampers the ability to monitor status of cells in a living brain. Extracellular vesicles (EVs), nanosized membrane-surrounded vesicles, released by virtually all brain cells might be able to report their status in easily accessible biofluids, such as blood. EVs communicate among tissues using lipids, saccharides, proteins, and nucleic acid cargo that reflect the state and composition of their source cells. Currently, identifying the origin of brain-derived EVs has been challenging, as they consist of a rare population diluted in an overwhelming number of blood and peripheral tissue-derived EVs. Here, we developed a sensitive platform to select out pre-labelled brain-derived EVs in blood as a platform to study the molecular fingerprints of brain cells. This proof-of-principle study used a transducible construct tagging tetraspanin (TSN) CD63, a membrane-spanning hallmark of EVs equipped with affinity, bioluminescent, and fluorescent tags to increase detection sensitivity and robustness in capture of EVs secreted from pre-labelled cells into biofluids. Our platform enables unprecedented efficient isolation of neural EVs from the blood. These EVs derived from pre-labelled mouse brain cells or engrafted human neuronal progenitor cells (hNPCs) were submitted to multiplex analyses, including transcript and protein levels, in compliance with the multibiomolecule EV carriers. Overall, our novel strategy to track brain-derived EVs in a complex biofluid opens up new avenues to study EVs released from pre-labelled cells in near and distal compartments into the biofluid source.

Nanocarriers Call the Last Shot in the Treatment of Brain Cancers

Our brain is protected by physio-biological barriers. The blood–brain barrier (BBB) main mechanism of protection relates to the abundance of tight junctions (TJs) and efflux pumps. Although BBB is crucial for healthy brain protection against toxins, it also leads to failure in a devastating disease like brain cancer. Recently, nanocarriers have been shown to pass through the BBB and improve patients’ survival rates, thus becoming promising treatment strategies. Among nanocarriers, inorganic nanocarriers, solid lipid nanoparticles, liposomes, polymers, micelles, and dendrimers have reached clinical trials after delivering promising results in preclinical investigations. The size of these nanocarriers is between 10 and 1000 nm and is modified by surface attachment of proteins, peptides, antibodies, or surfactants. Multiple research groups have reported transcellular entrance as the main mechanism allowing for these nanocarriers to cross BBB. Transport proteins and transcellular lipophilic pathways exist in BBB for small and lipophilic molecules. Nanocarriers cannot enter via the paracellular route, which is limited to water-soluble agents due to the TJs and their small pore size. There are currently several nanocarriers in clinical trials for the treatment of brain cancer. This article reviews challenges as well as fitting attributes of nanocarriers for brain tumor treatment in preclinical and clinical studies.

Regenerative medicine and traumatic brain injury: from stem cell to cell-free therapeutic strategies

Traumatic brain injury (TBI) is a serious health concern, yet there is a lack of standardized treatment to combat its long-lasting effects. The objective of the present study was to provide an overview of the limitation of conventional stem-cell therapy in the treatment of TBI and to discuss the application of novel acellular therapies and their advanced strategies to enhance the efficacy of stem cells derived therapies in the light of published study data. Moreover, we also discussed the factor to optimize the therapeutic efficiency of stem cell-derived acellular therapy by overcoming the challenges for its clinical translation. Hence, we concluded that acellular therapy possesses the potential to bring a breakthrough in the field of regenerative medicine to treat TBI.

Osteosarcoma from the unknown to the use of exosomes as a versatile and dynamic therapeutic approach

The most common primary malignant tumor of bone in children is osteosarcoma (OS). Nowadays, the prognosis and the introduction of chemotherapy in OS have improved survival rates of patients. Nevertheless, the results are still unsatisfactory, especially, in patients with recurrent disease or metastatic. OS chemotherapy has two main challenges related to treatment toxicity and multiple drug resistance. In this way, nanotechnology has developed nanosystems capable of releasing the drug directly at the OS cells and decreasing the drug's toxicity. Exosomes (Exo), a cell-derived nano-sized and a phospholipid vehicle, have been recognized as important drug delivery systems in several cancers. They are involved in a variety of biological processes and are an important mediator of long-distance intercellular communication. Exo can reduce inflammation and show low toxicity in healthy cells. Furthermore, the incorporation of specific proteins or peptides on the Exo surface improves their targeting capability in several clinical applications. Due to their unique structure and relevant characteristics, Exo is a promising nanocarrier for OS treatment. This review intends to describe the properties that turn Exo into an efficient, as well as safe nanovesicle for drug delivery and treatment of OS.

The impact of obesity on adipocyte-derived extracellular vesicles

Recently, the emerging roles of adipocyte-derived extracellular vesicles (EVs) linking obesity and its comorbidities have been recognized. In obese subjects, adipocytes are having hypertrophic growth and are under stressed. The dysfunction adipocytes dysregulate the assembly of the biological components in the EVs including exosomes. This article critically reviews the current findings on the impact of obesity on the exosomal cargo contents that induce the pathophysiological changes. Besides, this review also summarizes the understanding on how obesity affects the biogenesis of adipocyte-derived exosomes and the exosome secretion. Furthermore, the differences of the exosomal contents in different adipose depots, and the impact of obesity on the exosomes that are derived from the stromal vascular fraction such as the adipose tissue macrophages and adipocyte-derived stem cells will also be discussed. The current development and potential application of exosome-based therapy will be summarized. This review provides crucial information for the design of novel exosome-based therapy for the treatment of obesity and its comorbidities.

Myricetin-Based Self-Assembled Nanoparticles for Tumor Synergistic Therapy by Antioxidation Pathway

Nanoplatforms are nano-scale systems that can transport different small molecular anticancer drugs or chemosensitization motif to accumulate in tumor cells without obvious side-effect in normal cells and achieve a synergistic therapy. In this paper the new self-assembled nanoparticles (NPs) merging doxorubicin (DOX) and myricetin (MYR) with ferric ions (Fe³⁺) and polyphenol was employed for forming the DOX@MYR-Fe³⁺ NP (FDMP NP). The FDMP NPs could reduce the DOX-induced toxicity in blood; and they could not cause damage to the heart and kidney tissues by the reasons that the MYR could enhance the anti-oxidation capability in normal cells, which resulted in preventing ROS-induced damage. Additionally, the FDMP NPs were characteristic of small size (37.70 ± 6.30 nm), high DOX loading efficiency (46.67 ± 1.58%), pH-controlled release and excellent stable pharmacokinetics, that inducing drug release and enhancing drug accumulation in the tumor. Moreover, the FDMP NPs could inhibit the expression of the hypoxia-inducible factor-1 α(HIF-1α) and the key angiogenesis mediator vascular endothelial growth factor (VEGF) both in vitro and in vivo, which succeed in preventing the generation of new blood vessel networks; that is the mechanism of the synergistic effect against tumors induced by FDMP NPs.

Targeting central nervous system extracellular vesicles enhanced triiodothyronine remyelination effect on experimental autoimmune encephalomyelitis

The lack of targeted and high-efficiency drug delivery to the central nervous system (CNS) nidus is the main problem in the treatment of demyelinating disease. Extracellular vesicles (EVs) possess great promise as a drug delivery vector given their advanced features. However, clinical applications are limited because of their inadequate targeting ability and the “dilution effects” after systemic administration. Neural stem cells (NSCs) supply a plentiful source of EVs on account of their extraordinary capacity for self-renewal. Here, we have developed a novel therapeutic system using EVs from modified NSCs with high expressed ligand PDGF-A (EVPs) and achieve local delivery. It has been demonstrated that EVPs greatly enhance the target capability on oligodendrocyte lineage. Moreover, EVPs are used for embedding triiodothyronine (T3), a thyroid hormone that is critical for oligodendrocyte development but has serious side effects when systemically administered. Our results demonstrated that systemic injection of EVPs + T3, versus EVPs or T3 administration individually, markedly alleviated disease development, enhanced oligodendrocyte survival, inhibited myelin damage, and promoted myelin regeneration in the lesions of experimental autoimmune encephalomyelitis mice. Taken together, our findings showed that engineered EVPs possess a remarkable CNS lesion targeting potential that offers a potent therapeutic strategy for CNS demyelinating diseases as well as neuroinflammation.

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NSC-derived EV-PDGFA dramatically increased targeting efficiency to the lineage of OLGs and the demyelinated area in the CNS.

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EVPs-T3 exert the therapeutic ability in the lesion suppressed the disease development and protected myelin loss.

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EVPs-T3 increased numbers of OLGs in the lesion and TEM data evidenced that EVPs-T3 promotes myelin regeneration in vivo.