In Vitro and in Vivo RNA Inhibition by CD9-HuR Functionalized Exosomes Encapsulated with miRNA or CRISPR/dCas9

Intrauterine Hypoxia and Epigenetic Programming in Lung Development and Disease

Clinically, intrauterine hypoxia is the foremost cause of perinatal morbidity and developmental plasticity in the fetus and newborn infant. Under hypoxia, deviations occur in the lung cell epigenome. Epigenetic mechanisms (e.g., DNA methylation, histone modification, and miRNA expression) control phenotypic programming and are associated with physiological responses and the risk of developmental disorders, such as bronchopulmonary dysplasia. This developmental disorder is the most frequent chronic pulmonary complication in preterm labor. The pathogenesis of this disease involves many factors, including aberrant oxygen conditions and mechanical ventilation-mediated lung injury, infection/inflammation, and epigenetic/genetic risk factors. This review is focused on various aspects related to intrauterine hypoxia and epigenetic programming in lung development and disease, summarizes our current knowledge of hypoxia-induced epigenetic programming and discusses potential therapeutic interventions for lung disease.

Extracellular vesicles as a drug delivery system: A systematic review of preclinical studies

During the past decades, extracellular vesicles (EVs) have emerged as an attractive drug delivery system. Here, we assess their pre-clinical applications, in the form of a systematic review. For each study published in the past decade, disease models, animal species, EV donor cell types, active pharmaceutical ingredients (APIs), EV surface modifications, API loading methods, EV size and charge, estimation of EV purity, presence of biodistribution studies and administration routes were quantitatively analyzed in a defined and reproducible way. We have interpreted the trends we observe over the past decade, to define the niches where to apply EVs for drug delivery in the future and to provide a basis for regulatory guidelines.

Quantification of protein cargo loading into engineered extracellular vesicles at single-vesicle and single-molecule resolution

Extracellular Vesicles (EVs) have been intensively explored for therapeutic delivery of proteins. However, methods to quantify cargo proteins loaded into engineered EVs are lacking. Here, we describe a workflow for EV analysis at the single-vesicle and single-molecule level to accurately quantify the efficiency of different EV-sorting proteins in promoting cargo loading into EVs. Expi293F cells were engineered to express EV-sorting proteins fused to green fluorescent protein (GFP). High levels of GFP loading into secreted EVs was confirmed by Western blotting for specific EV-sorting domains, but quantitative single-vesicle analysis by Nanoflow cytometry detected GFP in less than half of the particles analysed, reflecting EV heterogeneity. Anti-tetraspanin EV immunostaining in ExoView confirmed a heterogeneous GFP distribution in distinct subpopulations of CD63+, CD81+, or CD9+ EVs. Loading of GFP into individual vesicles was quantified by Single-Molecule Localization Microscopy. The combined results demonstrated TSPAN14, CD63 and CD63/CD81 fused to the PDGFRβ transmembrane domain as the most efficient EV-sorting proteins, accumulating on average 50-170 single GFP molecules per vesicle. In conclusion, we validated a set of complementary techniques suitable for high-resolution analysis of EV preparations that reliably capture their heterogeneity, and propose highly efficient EV-sorting proteins to be used in EV engineering applications.

Designer exosomes for targeted and efficient ferroptosis induction in cancer via chemo-photodynamic therapy

Background: Efficient and specific induction of cell death in liver cancer is urgently needed. In this study, we aimed to design an exosome-based platform to deliver ferroptosis inducer (Erastin, Er) and photosensitizer (Rose Bengal, RB) into tumor tissues with high specificity. Methods: Exosome donor cells (HEK293T) were transfected with control or CD47-overexpressing plasmid. Exosomes were isolated and loaded with Er and RB via sonication method. Hepa1-6 cell xenograft C57BL/6 model was injected with control and engineered exosomes via tail vein. In vivo distribution of the injected exosomes was analyzed via tracking the fluorescence labeled exosomes. Photodynamic therapy was conducted by 532 nm laser irradiation. The therapeutic effects on hepatocellular carcinoma and toxic side-effects were systemically analyzed. Results: CD47 was efficiently loaded on the exosomes from the donor cells when CD47 was forced expressed by transfection. CD47 surface functionalization (ExosCD47) made the exosomes effectively escape the phagocytosis of mononuclear phagocyte system (MPS), and thus increased the distribution in tumor tissues. Erastin and RB could be effectively encapsulated into exosomes after sonication, and the drug-loaded exosomes (Er/RB@ExosCD47) strongly induced ferroptosis both in vitro and in vivo in tumor cells after irradiation of 532 nm laser. Moreover, compared with the control exosomes (Er/RB@ExosCtrl), Er/RB@ExosCD47 displayed much lower toxicity in liver. Conclusion: The engineered exosomes composed of CD47, Erastin, and Rose Bengal, induce obvious ferroptosis in hepatocellular carcinoma (HCC) with minimized toxicity in liver and kidney. The proposed exosomes would provide a promising strategy to treat types of malignant tumors.

The Multifaceted Role of Extracellular Vesicles in Glioblastoma: microRNA Nanocarriers for Disease Progression and Gene Therapy

Glioblastoma (GB) is the most aggressive form of brain cancer in adults, characterized by poor survival rates and lack of effective therapies. MicroRNAs (miRNAs) are small, non-coding RNAs that regulate gene expression post-transcriptionally through specific pairing with target messenger RNAs (mRNAs). Extracellular vesicles (EVs), a heterogeneous group of cell-derived vesicles, transport miRNAs, mRNAs and intracellular proteins, and have been shown to promote horizontal malignancy into adjacent tissue, as well as resistance to conventional therapies. Furthermore, GB-derived EVs have distinct miRNA contents and are able to penetrate the blood-brain barrier. Numerous studies have attempted to identify EV-associated miRNA biomarkers in serum/plasma and cerebrospinal fluid, but their collective findings fail to identify reliable biomarkers that can be applied in clinical settings. However, EVs carrying specific miRNAs or miRNA inhibitors have great potential as therapeutic nanotools in GB, and several studies have investigated this possibility on in vitro and in vivo models. In this review, we discuss the role of EVs and their miRNA content in GB progression and resistance to therapy, with emphasis on their potential as diagnostic, prognostic and disease monitoring biomarkers and as nanocarriers for gene therapy.

Potential Use of Exosomes as Diagnostic Biomarkers and in Targeted Drug Delivery: Progress in Clinical and Preclinical Applications

Exosomes are cell-derived vesicles containing heterogeneous active biomolecules such as proteins, lipids, mRNAs, receptors, immune regulatory molecules, and nucleic acids. They typically range in size from 30 to 150 nm in diameter. An exosome's surfaces can be bioengineered with antibodies, fluorescent dye, peptides, and tailored for small molecule and large active biologics. Exosomes have enormous potential as a drug delivery vehicle due to enhanced biocompatibility, excellent payload capability, and reduced immunogenicity compared to alternative polymeric-based carriers. Because of active targeting and specificity, exosomes are capable of delivering their cargo to exosome-recipient cells. Additionally, exosomes can potentially act as early stage disease diagnostic tools as the exosome carries various protein biomarkers associated with a specific disease. In this review, we summarize recent progress on exosome composition, biological characterization, and isolation techniques. Finally, we outline the exosome's clinical applications and preclinical advancement to provide an outlook on the importance of exosomes for use in targeted drug delivery, biomarker study, and vaccine development.

CRISPR/Cas9: Principle, Applications, and Delivery through Extracellular Vesicles

The establishment of CRISPR/Cas9 (clustered regularly interspaced short palindromic repeats/CRISPR-associated protein 9) technology for eukaryotic gene editing opened up new avenues not only for the analysis of gene function but also for therapeutic interventions. While the original methodology allowed for targeted gene disruption, recent technological advancements yielded a rich assortment of tools to modify genes and gene expression in various ways. Currently, clinical applications of this technology fell short of expectations mainly due to problems with the efficient and safe delivery of CRISPR/Cas9 components to living organisms. The targeted in vivo delivery of therapeutic nucleic acids and proteins remain technically challenging and further limitations emerge, for instance, by unwanted off-target effects, immune reactions, toxicity, or rapid degradation of the transfer vehicles. One approach that might overcome many of these limitations employs extracellular vesicles as intercellular delivery devices. In this review, we first introduce the CRISPR/Cas9 system and its latest advancements, outline major applications, and summarize the current state of the art technology using exosomes or microvesicles for transporting CRISPR/Cas9 constituents into eukaryotic cells.

Advances in Biological Function and Clinical Application of Small Extracellular Vesicle Membrane Proteins

Small extracellular vesicles are membrane-bound vesicles secreted into extracellular spaces by virtually all types of cells. These carry a large number of membrane proteins on their surface that are incorporated during their biogenesis in cells. The composition of the membrane proteins hence bears the signature of the cells from which they originate. Recent studies have suggested that the proteins on these small extracellular vesicles can serve as biomarkers and target proteins for the diagnosis and treatment of diseases. This article classifies small extracellular vesicle membrane proteins and summarizes their pathophysiological functions in the diagnosis and treatment of diseases.

Nanoparticle Delivery of CRISPR/Cas9 for Genome Editing

The emerging clustered regularly interspaced short palindromic repeat (CRISPR)/CRISPR-associated system (Cas) gene-editing system represents a promising tool for genome manipulation. However, its low intracellular delivery efficiency severely compromises its use and potency for clinical applications. Nanocarriers, such as liposomes, polymers, and inorganic nanoparticles, have shown great potential for gene delivery. The remarkable development of nanoparticles as non-viral carriers for the delivery of the CRISPR/Cas9 system has shown great promise for therapeutic applications. In this review, we briefly summarize the delivery components of the CRISPR/Cas9 system and report on the progress of nano-system development for CRISPR/Cas9 delivery. We also compare the advantages of various nano-delivery systems and their applications to deliver CRISPR/Cas9 for disease treatment. Nano-delivery systems can be modified to fulfill the tasks of targeting cells or tissues. We primarily emphasize the novel exosome-based CRISPR/Cas9 delivery system. Overall, we review the challenges, development trends, and application prospects of nanoparticle-based technology for CRISPR/Cas9 delivery.

Designer Exosomes: A New Platform for Biotechnology Therapeutics

Abstract

Desirable features of exosomes have made them a suitable manipulative platform for biomedical applications, including targeted drug delivery, gene therapy, cancer diagnosis and therapy, development of vaccines, and tissue regeneration. Although natural exosomes have various potentials, their clinical application is associated with some inherent limitations. Recently, these limitations inspired various attempts to engineer exosomes and develop designer exosomes. Mostly, designer exosomes are being developed to overcome the natural limitations of exosomes for targeted delivery of drugs and functional molecules to wounds, neurons, and the cardiovascular system for healing of damage. In this review, we summarize the possible improvements of natural exosomes by means of two main approaches: parental cell-based or pre-isolation exosome engineering and direct or post-isolation exosome engineering. Parental cell-based engineering methods use genetic engineering for loading of therapeutic molecules into the lumen or displaying them on the surface of exosomes. On the other hand, the post-isolation exosome engineering approach uses several chemical and mechanical methods including click chemistry, cloaking, bio-conjugation, sonication, extrusion, and electroporation. This review focuses on the latest research, mostly aimed at the development of designer exosomes using parental cell-based engineering and their application in cancer treatment and regenerative medicine.

Graphic Abstract

Multifaceted Roles of Adipose Tissue-Derived Exosomes in Physiological and Pathological Conditions

Adipose tissue functions importantly in the bodily homeostasis and systemic metabolism, while obesity links to multiple disorders. Beyond the canonical hormones, growth factors and cytokines, exosomes have been identified to play important roles in transmission of information from adipose tissue to other organs. Exosomes are nanoscale membrane vesicles secreted by donor cells, and transfer the genetic information to the recipient cells where the encapsulated nucleic acids and proteins are released. In this review, we elaborate the recent advances in the biogenesis and profiling of adipose tissue derived exosomes, and their physiological and pathological effects on different organs. Moreover, the potential significance of the exosomes as therapeutic vehicles or drugs is also discussed.

Engineered Extracellular Vesicles for Cancer Therapy

Extracellular vesicles (EVs) have emerged as a novel cell-free strategy for the treatment of many diseases including cancer. As a result of their natural properties to mediate cell-to-cell communication and their high physiochemical stability and biocompatibility, EVs are considered as excellent delivery vehicles for a variety of therapeutic agents such as nucleic acids and proteins, drugs, and nanomaterials. Increasing studies have shown that EVs can be modified, engineered, or designed to improve their efficiency, specificity, and safety for cancer therapy. Herein, a comprehensive overview of the recent advances in the strategies and methodologies of engineering EVs for scalable production and improved cargo-loading and tumor-targeting is provided. Additionally, the potential applications of engineered EVs in cancer therapy are discussed by presenting prominent examples, and the opportunities and challenges for translating engineered EVs into clinical practice are evaluated.

A Novel Peptide-Equipped Exosomes Platform for Delivery of Antisense Oligonucleotides

Exosomes are natural delivery vehicles because of their original feature such as low immunogenicity, excellent biocompatibility, and migration capability. Engineering exosomes with appropriate ligands are effective approaches to improve the low cellular uptake efficiency of exosomes. However, current strategies face considerable challenges due to the tedious and labor-intensive operational process. Here, we designed a novel peptides-equipped exosomes platform which can be assembled under convenient and mild reaction condition. Cell-penetrating peptides (CPPs) was conjugated on HepG2 cells-derived exosomes surface which can not only enhance the penetrating capacity of exosomes but also assist exosomes in loading antisense oligonucleotides (ASOs). The cellular uptake mechanism was investigated and we compared the difference between natural exosomes and modified exosomes. The resulting nanosystem demonstrated a preferential tropism for cells that are parented to their source tumor cells and could remarkably increase the cellular delivery of G3139 with efficient downregulation of antiapoptotic Bcl-2. This work developed a rapid strategy for intracellular delivery of nucleic acids, thus providing more possibilities toward personalized cancer medicine.

Exosomes in atherosclerosis: performers, bystanders, biomarkers, and therapeutic targets

Exosomes are nanosized lipid vesicles originating from the endosomal system that carry many macromolecules from their parental cells and play important roles in intercellular communication. The functions and underlying mechanisms of exosomes in atherosclerosis have recently been intensively studied. In this review, we briefly introduce exosome biology and then focus on advances in the roles of exosomes in atherosclerosis, specifically exosomal changes associated with atherosclerosis, their cellular origins and potential functional cargos, and their detailed impacts on recipient cells. We also discuss the potential of exosomes as biomarkers and drug carriers for managing atherosclerosis.

Overview and Update on Methods for Cargo Loading into Extracellular Vesicles

The enormous library of pharmaceutical compounds presents endless research avenues. However, several factors limit the therapeutic potential of these drugs, such as drug resistance, stability, off-target toxicity, and inadequate delivery to the site of action. Extracellular vesicles (EVs) are lipid bilayer-delimited particles and are naturally released from cells. Growing evidence shows that EVs have great potential to serve as effective drug carriers. Since EVs can not only transfer biological information, but also effectively deliver hydrophobic drugs into cells, the application of EVs as a novel drug delivery system has attracted considerable scientific interest. Recently, EVs loaded with siRNA, miRNA, mRNA, CRISPR/Cas9, proteins, or therapeutic drugs show improved delivery efficiency and drug effect. In this review, we summarize the methods used for the cargo loading into EVs, including siRNA, miRNA, mRNA, CRISPR/Cas9, proteins, and therapeutic drugs. Furthermore, we also include the recent advance in engineered EVs for drug delivery. Finally, both advantages and challenges of EVs as a new drug delivery system are discussed. Here, we encourage researchers to further develop convenient and reliable loading methods for the potential clinical applications of EVs as drug carriers in the future.

Prospects and challenges of extracellular vesicle-based drug delivery system: considering cell source

Extracellular vesicles (EVs), including exosomes, microvesicles, and apoptotic bodies, are nanosized membrane vesicles derived from most cell types. Carrying diverse biomolecules from their parent cells, EVs are important mediators of intercellular communication and thus play significant roles in physiological and pathological processes. Owing to their natural biogenesis process, EVs are generated with high biocompatibility, enhanced stability, and limited immunogenicity, which provide multiple advantages as drug delivery systems (DDSs) over traditional synthetic delivery vehicles. EVs have been reported to be used for the delivery of siRNAs, miRNAs, protein, small molecule drugs, nanoparticles, and CRISPR/Cas9 in the treatment of various diseases. As a natural drug delivery vectors, EVs can penetrate into the tissues and be bioengineered to enhance the targetability. Although EVs' characteristics make them ideal for drug delivery, EV-based drug delivery remains challenging, due to lack of standardized isolation and purification methods, limited drug loading efficiency, and insufficient clinical grade production. In this review, we summarized the current knowledge on the application of EVs as DDS from the perspective of different cell origin and weighted the advantages and bottlenecks of EV-based DDS.

Extracellular vesicles in cancer nanomedicine

To date, a lot of nanotechnological optitions are available for targeted drug delivery. Extracellular vesicles (EVs) are membrane structures that cells use for storage, transport, communication, and signaling. Recent research has focused on EVs as natural nanoparticles for drug delivery. This review sheds light on the application of EVs in cancer therapy, such as targeted chemotherapy, gene therapy, and vaccine development. Aspects of biogenesis, isolation, targeting, and loading of EVs are discussed in detail.

Exosome-mediated delivery of gene vectors for gene therapy

Gene vectors are nucleic acids that carry genetic materials or gene editing devices into cells to exert the sustained production of therapeutic proteins or to correct erroneous genes of the cells. However, the cell membrane sets a barrier for the entry of nucleic acid molecules, and nucleic acids are easily degraded or neutralized when they are externally administered into the body. Carriers to encapsulate, protect and deliver nucleic acid molecules therefore are essential for clinical applications of gene therapy. The secreted organelles, exosomes, which naturally mediate the communications between cells, have been engineered to encapsulate and deliver nucleic acids to the desired tissues and cells. The fusion of exosomes with liposomes can increase the loading capacity and also retain the targeting capability of exosomes. Altogether, this review summarizes the most recent designs of exosome-based applications for gene delivery and their future perspectives in gene therapy.

The Multifunctionality of Exosomes; from the Garbage Bin of the Cell to a Next Generation Gene and Cellular Therapy

Exosomes are packaged with a variety of cellular cargo including RNA, DNA, lipids and proteins. For several decades now there has been ongoing debate as to what extent exosomes are the garbage bin of the cell or if these entities function as a distributer of cellular cargo which acts in a meaningful mechanistic way on target cells. Are the contents of exosomes unwanted excess cellular produce or are they selective nucleic acid packaged nanoparticles used to communicate in a paracrine fashion? Overexpressed RNAs and fragments of DNA have been shown to collect into exosomes which are jettisoned from cells in response to particular stimuli to maintain homeostasis suggesting exosomes are functional trash bins of the cell. Other studies however have deciphered selective packaging of particular nucleic acids into exosomes. Nucleic acids packaged into exosomes are increasingly reported to exert transcriptional control on recipient cells, supporting the notion that exosomes may provide a role in signaling and intracellular communication. We survey the literature and conclude that exosomes are multifunctional entities, with a plethora of roles that can each be taken advantage to functionally modulate cells. We also note that the potential utility of developing exosomes as a next generation genetic therapy may in future transform cellular therapies. We also depict three models of methodologies which can be adopted by researchers intending to package nucleic acid in exosomes for developing gene and cell therapy.

Exosome-based Ldlr gene therapy for familial hypercholesterolemia in a mouse model

Familial hypercholesterolemia (FH), with high LDL (low-density lipoprotein) cholesterol levels, is due to inherited mutations in genes, such as low-density lipoprotein receptor (LDLR). Development of therapeutic strategies for FH, which causes atherosclerosis and cardiovascular disease, is urgently needed.

Methods: Mice with low-density lipoprotein receptor (Ldlr) deletion (Ldlr^-/- mice) were used as an FH model. Ldlr mRNA was encapsulated into exosomes by forced expression of Ldlr in the donor AML12 (alpha mouse liver) cells, and the resultant exosomes were denoted as Exo^Ldlr. In vivo distribution of exosomes was analyzed by fluorescence labeling and imaging. The delivery efficiency of Ldlr mRNA was analyzed by qPCR and Western blotting. Therapeutic effects of Exo^Ldlr were examined in Ldlr^-/- mice by blood lipids and Oil Red O staining.

Results: The encapsulated mRNA was stable and could be translated into functional protein in the recipient cells. Following tail vein injection, exosomes were mainly delivered into the liver, producing abundant LDLR protein, resembling the endogenous expression profile in the wild-type mouse. Compared with control exosomes, Exo^Ldlr treatment significantly decreased lipid deposition in the liver and lowered the serum LDL-cholesterol level. Significantly, the number and size of atherosclerotic plaques and inflammation were reduced in the Exo^Ldlr-treated mice.

Conclusions: We have shown that exosome-mediated Ldlr mRNA delivery effectively restored receptor expression, treating the disorders in the Ldlr^-/- mouse. Our study provided a new therapeutic approach for the treatment of FH patients and managing atherosclerosis.

Extracellular-vesicles delivered tumor-specific sequential nanocatalysts can be used for MRI-informed nanocatalytic Therapy of hepatocellular carcinoma

Background: Conventional therapeutic strategies for advanced hepatocellular carcinoma (HCC) remains a great challenge, therefore the alternative therapeutic modality for specific and efficient HCC suppression is urgently needed. Methods: In this work, HCC-derived extracellular vesicles (EVs) were applied as surface nanocarrier for sequential nanocatalysts GOD-ESIONs@EVs (GE@EVs) of tumor-specific and cascade nanocatalytic therapy against HCC. By enhancing the intracellular endocytosis through arginine-glycine-aspartic acid (RGD)-targeting effect and membrane fusion, sequential nanocatalysts led to more efficient treatment in the HCC tumor region in a shorter period of time. Results: Through glucose consumption as catalyzed by the loaded glucose oxidase (GOD) to overproduce hydrogen peroxide (H2O2), highly toxic hydroxyl radicals were generated by Fenton-like reaction as catalyzed by ESIONs, which was achieved under the mildly acidic tumor microenvironment, enabling the stimuli of the apoptosis and necrosis of HCC cells. This strategy demonstrated the high active-targeting capability of GE@EVs into HCC, achieving highly efficient tumor suppression both in vitro and in vivo. In addition, the as-synthesized nanoreactor could act as a desirable nanoscale contrast agent for magnetic resonance imaging, which exhibited desirable imaging capability during the sequential nanocatalytic treatment. Conclusion: This application of surface-engineering EVs not only proves the high-performance catalytic therapeutic modality of GE@EVs for HCC, but also broadens the versatile bio-applications of EVs.

Delivery Efficacy Differences of Intravenous and Intraperitoneal Injection of Exosomes: Perspectives from Tracking Dye Labeled and MiRNA Encapsulated Exosomes

BACKGROUND

Exosomes are cell-derived nanovesicles that play vital roles in intercellular communication. Recently, exosomes are recognized as promising drug delivery vehicles. Up till now, how the in vivo distribution of exosomes is affected by different administration routes has not been fully understood.

METHODS

In the present study, in vivo distribution of exosomes following intravenous and intraperitoneal injection approaches was systemically analyzed by tracking the fluorescence-labeled exosomes and qPCR analysis of C. elegans specific miRNA abundance delivered by exosomes in different organs.

RESULTS

The results showed that exosomes administered through tail vein were mostly taken up by the liver, spleen and lungs while exosomes injected intraperitoneally were more dispersedly distributed. Besides the liver, spleen, and lungs, intraperitoneal injection effectively delivered exosomes into the visceral adipose tissue, making it a promising strategy for obesity therapy. Moreover, the results from fluorescence tracking and qPCR were slightly different, which could be explained by systemic errors.

CONCLUSION

Together, our study reveals that different administration routes cause a significant differential in vivo distribution of exosomes, suggesting that optimization of the delivery route is prerequisite to obtain rational delivery efficiency in detailed organs.

Rational designs of in vivo CRISPR-Cas delivery systems

The CRISPR-Cas system initiated a revolution in genome editing when it was, for the first time, demonstrated success in the mammalian cells. Today, scientists are able to readily edit genomes, regulate gene transcription, engineer posttranscriptional events, and image nucleic acids using CRISPR-Cas-based tools. However, to efficiently transport CRISPR-Cas into target tissues/cells remains challenging due to many extra- and intra-cellular barriers, therefore largely limiting the applications of CRISPR-based therapeutics in vivo. In this review, we summarize the features of plasmid-, RNA- and ribonucleoprotein (RNP)-based CRISPR-Cas therapeutics. Then, we survey the current in vivo delivery systems. We specify the requirements for efficient in vivo delivery in clinical settings, and highlight both efficiency and safety for different CRISPR-Cas tools.

Does microRNA Perturbation Control the Mechanisms Linking Obesity and Diabetes? Implications for Cardiovascular Risk

Metabolic disorders such as obesity and type 2 diabetes (T2D) are considered the major risk factors for the development of cardiovascular diseases (CVD). Although the pathological mechanisms underlying the mutual development of obesity and T2D are difficult to define, a better understanding of the molecular aspects is of utmost importance to identify novel therapeutic targets. Recently, a class of non-coding RNAs, called microRNAs (miRNAs), are emerging as key modulators of metabolic abnormalities. There is increasing evidence supporting the role of intra- and extracellular miRNAs as determinants of the crosstalk between adipose tissues, liver, skeletal muscle and other organs, triggering the paracrine communication among different tissues. miRNAs may be considered as risk factors for CVD due to their correlation with cardiovascular events, and in particular, may be related to the most prominent risk factors. In this review, we describe the associations observed between miRNAs expression levels and the most common cardiovascular risk factors. Furthermore, we sought to depict the molecular aspect of the interplay between obesity and diabetes, investigating the role of microRNAs in the interorgan crosstalk. Finally, we discussed the fascinating hypothesis of the loss of protective factors, such as antioxidant defense systems regulated by such miRNAs.

Extracellular Vesicles as Unique Signaling Messengers: Role in Lung Diseases

Extracellular vesicles (EVs) are lipid bilayer-enclosed extracellular particles carrying rich cargo such as proteins, lipids, and microRNAs with distinct characteristics of their parental cells. EVs are emerging as an important form of cellular communication with the ability to selectively deliver a kit of directional instructions to nearby or distant cells to modulate their functions and phenotypes. According to their biogenesis, EVs can be divided into two groups: those of endocytic origin are called exosomes and those derived from outward budding of the plasma membrane are called microvesicles (also known as ectosomes or microparticles). Under physiological conditions, EVs are actively involved in maintenance of pulmonary hemostasis. However, EVs can contribute to the pathogenesis of diseases such as chronic obstructive pulmonary disease, asthma, acute lung injury/acute respiratory distress syndrome, interstitial lung disease, and pulmonary arterial hypertension. EVs, especially those derived from mesenchymal/stromal stem cells, can also be beneficial and can curb the development of lung diseases. Novel technologies are continuously being developed to minimize the undesirable effects of EVs and also to engineer EVs so that they may have beneficial effects and can be used as therapeutic agents in lung diseases. © 2021 American Physiological Society. Compr Physiol 11:1351-1369, 2021.

The roles of exosomes in cancer drug resistance and its therapeutic application

Exosomes are a category of extracellular vesicles with a size ranging from 40 to 160 nm, which can be secreted by multiple cells in the tumor microenvironment. Exosomes serve as communicators in regulating biological functions and pathological processes, including drug response. Through transporting the cargo such as protein or nucleic acid, exosomes can modulate drug sensitivity via multiple mechanisms. Additionally, exosomes can be deployed as a delivery system to treat cancer due to their high-efficient loading capacity and tolerable toxicity. Recent studies have demonstrated the high efficacy of exosomes in cancer therapy. Herein, we conduct this review to summarize the mechanism of exosome-mediated drug resistance and the therapeutic potential of exosomes in cancer.

Extracellular vesicles: A bright star of nanomedicine

Extracellular vesicles (EVs) have unique structural, compositional, and morphological characteristics as well as predominant physiochemical stability and biocompatibility properties. They play a crucial role in pathophysiological regulation, and also have broad prospects for clinical application in the diagnosis, prognosis, and therapy of disease, and tissue regeneration and repair. Herein, the biosynthesis and physiological functions and current methods for separation and identification of EVs are summarized. Specifically, engineered EVs may be used to enhance targeted therapy in cancer and repair damaged tissues, and they may be developed as an individualized imaging diagnostic reagent, among other potential applications. We will focus on reviewing recent studies on engineered EVs in which alterations enhanced their therapeutic capability or diagnostic imaging potential via physical, chemical, and biological modification approaches. This review will clarify the superior biological functions and powerful therapeutic potential of EVs, particularly with regard to new designs based on EVs and their utilization in a new generation of nanomedicine diagnosis and treatment platforms.

The Role of Exosomal microRNAs and Oxidative Stress in Neurodegenerative Diseases

Neurodegenerative diseases including Alzheimer's disease and Parkinson's disease are aging-associated diseases with irreversible damage of brain tissue. Oxidative stress is commonly detected in neurodegenerative diseases and related to neuronal injury and pathological progress. Exosome, one of the extracellular vesicles, is demonstrated to carry microRNAs (miRNAs) and build up a cell-cell communication in neurons. Recent research has found that exosomal miRNAs regulate the activity of multiple physiological pathways, including the oxidative stress response, in neurodegenerative diseases. Here, we review the role of exosomal miRNAs and oxidative stress in neurodegenerative diseases. Firstly, we explore the relationship between oxidative stress and neurodegenerative diseases. Secondly, we introduce the characteristics of exosomes and roles of exosome-related miRNAs. Thirdly, we summarized the crosstalk between exosomal miRNAs and oxidative stress in neurodegenerative diseases. Fourthly, we discuss the potential of exosomes to be a biomarker in neurodegenerative diseases. Finally, we summarize the advantages of exosome-based delivery and present situation of research on exosome-based delivery of therapeutic miRNA. Our work is aimed at probing and reinforcing the recognition of the pathomechanism of neurodegenerative diseases and providing the basis for novel strategies of clinical diagnosis and treatment.

Extracellular Vesicle-Based Nucleic Acid Delivery: Current Advances and Future Perspectives in Cancer Therapeutic Strategies

Extracellular vesicles (EVs) are sophisticated and sensitive messengers released by cells to communicate with and influence distant and neighboring cells via selective transfer of bioactive content, including protein lipids and nucleic acids. EVs have therefore attracted broad interest as new and refined potential therapeutic systems in many diseases, including cancer, due to their low immunogenicity, non-toxicity, and elevated bioavailability. They might serve as safe and effective vehicles for the transport of therapeutic molecules to specific tissues and cells. In this review, we focus on EVs as a vehicle for gene therapy in cancer. We describe recent developments in EV engineering to achieve efficient intracellular delivery of cancer therapeutics and avoid off-target effects, to provide an overview of the potential applications of EV-mediated gene therapy and the most promising biomedical advances.

Exosome: A Review of Its Classification, Isolation Techniques, Storage, Diagnostic and Targeted Therapy Applications

Exosomes are nano-sized small extracellular vesicles secreted by cells, carrying nucleic acids, proteins, lipids and other bioactive substances to play a role in the body's physiological and pathological processes. Compared to synthetic carriers such as liposomes and nanoparticles, the endogeneity and heterogeneity of exosomes give them extensive and unique advantages in the field of disease diagnosis and treatment. However, the storage stability, low yield, low purity, and weak targeting of exosomes limit its clinical application. For this reason, further exploration is needed to optimize the above problems and facilitate future functional studies of exosomes. In this paper, the origin, classification, preparation and characterization, storage stability and applications of exosome delivery system are summarized and discussed by searching a large number of literatures.

Engineered Extracellular Vesicles: Tailored-Made Nanomaterials for Medical Applications

Extracellular vesicles (EVs) are emerging as promising nanoscale therapeutics due to their intrinsic role as mediators of intercellular communication, regulating tissue development and homeostasis. The low immunogenicity and natural cell-targeting capabilities of EVs has led to extensive research investigating their potential as novel acellular tools for tissue regeneration or for the diagnosis of pathological conditions. However, the clinical use of EVs has been hindered by issues with yield and heterogeneity. From the modification of parental cells and naturally-derived vesicles to the development of artificial biomimetic nanoparticles or the functionalisation of biomaterials, a multitude of techniques have been employed to augment EVs therapeutic efficacy. This review will explore various engineering strategies that could promote EVs scalability and therapeutic effectiveness beyond their native utility. Herein, we highlight the current state-of-the-art EV-engineering techniques with discussion of opportunities and obstacles for each. This is synthesised into a guide for selecting a suitable strategy to maximise the potential efficacy of EVs as nanoscale therapeutics.

Extracellular Vesicles - Advanced Nanocarriers in Cancer Therapy: Progress and Achievements

Extracellular vesicles (EVs) are a class of cell-derived, lipid bilayer membrane composed vesicles, and some of them such as exosomes and ectosomes have been proven, playing remarkable roles in transmitting intercellular information, and being involved in each property of cell physiological activities. Nowadays, EVs are considered as potential nanocarriers which could partially resolve the problems of current chemotherapy because of their distinctive advantages. As endogenous membrane encompassed vesicles with nanosize, EVs are able to pass through the natural barriers with prolonged circulation time in vivo and have intrinsic cell targeting properties, they are less toxic, and less immunogenic. Recently, studies focusing on EV-based drug delivery system for cancer therapy have exploded dramatically. This review aims to outline the current applications of EVs as potential nanosized drug carriers in cancer therapy. Firstly, the characteristics and biofunctions of each EV subtype are described. Then the variety of therapeutic cargoes, the loading methods, and the targeting strategy of engineered EVs are emphatically introduced. Thereafter the pros and cons of EVs applied as therapeutic carriers, as well as the future prospects in this field, are discussed.

Chondrocyte-Targeted MicroRNA Delivery by Engineered Exosomes toward a Cell-Free Osteoarthritis Therapy

Targeted delivery to the diseased cell or tissue is the key to the successful clinical use of nucleic acid drugs. In particular, delivery of microRNA-140 (miRNA-140, miR-140) into chondrocytes across the dense, nonvascular extracellular matrix of cartilage remains a major challenge. Here, we report the chondrocyte-targeting exosomes as vehicles for the delivery of miR-140 into chondrocytes as a new treatment for osteoarthritis (OA). By fusing a chondrocyte-affinity peptide (CAP) with the lysosome-associated membrane glycoprotein 2b protein on the surface of exosomes, we acquire CAP-exosomes that can efficiently encapsulate miR-140, specifically enter, and deliver the cargo into chondrocytes in vitro. CAP-exosomes, in contrast to nontagged exosome vesicles, are retained in the joints after intra-articular injection with minimal diffusion in vivo. CAP-exosomes also deliver miR-140 to deep cartilage regions through the dense mesochondrium, inhibit cartilage-degrading proteases, and alleviate OA progression in a rat model, pointing toward a potential organelle-based, cell-free therapy of OA.

Exosome-mediated delivery of miR-204-5p inhibits tumor growth and chemoresistance

BACKGROUND

Nano-sized extracellular vesicles secreted by cells play key roles in intercellular crosstalk, and appear to be an excellent biocompatible material as therapeutic cargoes in vivo. Previously, we have demonstrated that miR-204-5p is a key tumor suppressor that could inhibit tumor growth, metastasis and chemoresistance.

METHODS

A HEK293T cell line stably expressing miR-204-5p (293T-miR-204) was constructed by lentivirus transduction. Fluorescence real-time quantitative PCR (qPCR) was applied to measure the expression of miR-204-5p. CCK-8 and colony formation assays were used to evaluate the in vitro anticancer effects, and the flow cytometry was used to detect apoptosis. The in vivo therapeutic effects of exosomal miR-204-5p were evaluated using a xenograft mouse model. Western blots were used to detect the protein levels of CD63, Flotillin-2, RAB22A and Bcl2. The protein levels of RAB22A and Bcl2 in tumor tissues were measured by immunohistochemistry staining.

RESULTS

MiR-204-5p was clearly upregulated in CRC cells after coculturing with 293T-miR-204 cell-derived conditioned medium (CM) or exosomes. CCK-8 and colony formation assays showed that the cell proliferation ability of CRC cells was clearly inhibited by 293T-miR-204 cell-derived CM or exosomes. The inhibitory effects of exosomal miR-204-5p on cell proliferation were further confirmed in other types of cancers. Exosomal miR-204-5p could induce apoptosis and increase the sensitivity of cancer cells to the chemotherapeutic drug-5-fluorourcil. In addition, exosomal miR-204-5p inhibited the tumor growth in mice. Western blot assay and IHC staining showed that the protein levels of miR-204-5p targets were clearly decreased in cancer cells or xenograft tissues treated with exosomal miR-204-5p.

CONCLUSIONS

In this study, we confirmed that exosomal miR-204-5p could efficiently inhibit cancer cell proliferation, induce apoptosis and increase chemosensitivity by specifically suppressing the target genes of miR-204-5p in human cancer cells.

Surface functionalization of exosomes for target-specific delivery and in vivo imaging & tracking: Strategies and significance

Exosomes are natural nanovesicles excreted by many cells for intercellular communication and for transfer of materials including proteins, nucleic acids and even synthetic therapeutic agents. Surface modification of exosomes imparts additional functionality to the exosomes to enable site specific drug delivery and in vivo imaging and tracking and is an emerging area in drug delivery research. The present review focuses upon these modifications on the exosomal surface, the chemistry involved and their impact on targeted drug delivery for the treatment of brain, breast, lung, liver, colon tumors and, heart diseases and for understanding their in vivo fate including their uptake mechanisms, pharmacokinetics and biodistribution. The specific exosomal membrane proteins such as tetraspanins (CD63, CD81, CD9), lactadherin (LA), lysosome associated membrane protein-2b (Lamp-2b) and, glycosyl-phosphatidyl-inositol (GPI) involved in functionalization of exosome surface have also been discussed along with different strategies of surface modification like genetic engineering, covalent modification (click chemistry and metabolic engineering of parent cells of exosomes) and non-covalent modification (multivalent electrostatic interactions, ligand-receptor interaction, hydrophobic interaction, aptamer based modification and modification by anchoring CP05 peptide) along with optical (fluorescent and bioluminescent) and radioactive isotope labelling techniques of exosomes for imaging purpose.

Extracellular vesicle-based Nanotherapeutics: Emerging frontiers in anti-inflammatory therapy

Dysregulated inflammation is a complicated pathological process involved in various diseases, and the treatment of inflammation-linked disorders currently represents an enormous global burden. Extracellular vesicles (EVs) are nanosized, lipid membrane-enclosed vesicles secreted by virtually all types of cells, which act as an important intercellular communicative medium. Considering their capacity to transfer bioactive substances, both unmodified and engineered EVs are increasingly being explored as potential therapeutic agents or therapeutic vehicles. Moreover, as the nature's own delivery tool, EVs possess many desirable advantages, such as stability, biocompatibility, low immunogenicity, low toxicity, and biological barrier permeability. The application of EV-based therapy to combat inflammation, though still in an early stage of development, has profound transformative potential. In this review, we highlight the recent progress in EV engineering for inflammation targeting and modulation, summarize their preclinical applications in the treatment of inflammatory disorders, and present our views on the anti-inflammatory applications of EV-based nanotherapeutics.

Brown adipose tissue-derived exosomes mitigate the metabolic syndrome in high fat diet mice

The ever-increasing incidence of obesity and related disorders impose serious challenges on public health worldwide. Brown adipose tissue (BAT) has strong capacity for promoting energy expenditure and has shown great potential in treating obesity. Exosomes are nanovesicles that share the characteristics of their donor cells. Whether BAT derived exosomes (BAT-Exos) might exert similar metabolic benefits on obesity is worthy of investigation. Methods: Obese mice were established by high-fat-diet (HFD) feeding and were treated with Seum-Exos or BAT-Exos isolated from young healthy mice. Blood glucose, glucose tolerance and blood lipids were tested in mice with indicated treatments. Histology examinations were performed on adipose tissue, liver and heart by HE staining and/or Oil Red O staining. Echocardiography was performed to evaluate cardiac function of mice. In vivo distribution of exosomes was analyzed by fluorescence labeling and imaging and in vitro effects of exosomes were evaluated by cell metabolism analysis. Protein contents of BAT-Exos were analyzed by mass spectrometry. Results: The results showed that BAT-Exos reduced the body weight, lowered blood glucose and alleviated lipid accumulation in HFD mice independently of food intake. Echocardiography revealed that the abnormal cardiac functions of HFD mice were significantly restored after treatment with BAT-Exos. Cell metabolism analysis showed that treatment with BAT-Exos significantly promoted oxygen consumption in recipient cells. Protein profiling of exosomes demonstrated that BAT-Exos were rich in mitochondria components and involved in catalytic processes. Conclusions: Collectively, our study showed that BAT-Exos significantly mitigated the metabolic syndrome in HFD mice. Detailed elucidation of the reactive molecules and mechanism of action would provide new insights in combating obesity and related disorders.

Promising RNA-based cancer gene therapy using extracellular vesicles for drug delivery

INTRODUCTION

RNA-based cancer gene therapy shows potential in cancer treatment. However, the safe and efficient transfer of therapeutic RNA to target cells has always been a challenge. The ideal drug delivery system should be effective with low immunogenicity and toxicity. Besides, a high specificity of drug delivery is necessary to improve efficacy and avoid the side effects associated with tumor heterogeneity. As endogenous RNA vehicles, extracellular vesicles (EVs) have shown their advantages and potential as drug delivery systems in gene therapy.

AREAS COVERED

We summarize the performance of EVs as a drug delivery system in RNA-based cancer gene therapy and discuss the advantages, limitations, and potentials of this translational medicine. In addition, we compare the characteristics and differences of current drug delivery systems and expound the principles of selecting a drug delivery system suitable for cancer gene therapy.

EXPERT OPINION

EVs are highly biocompatible membrane structures with low cytotoxicity which provide a new choice for drug delivery in RNA-based cancer gene therapy. The specificity of engineered EVs and artificial EV-mimetics can be improved through peptide or polymer decoration. However, apart from therapeutic RNA, EVs naturally carry many molecules. This may lead to unpredictable effects and thus should be applied with caution.

Therapeutic Effects of Simultaneous Delivery of Nerve Growth Factor mRNA and Protein via Exosomes on Cerebral Ischemia

Stroke is the leading neurological cause of death and disability all over the world, with few effective drugs. Nerve growth factor (NGF) is well known for its multifaceted neuroprotective functions post-ischemia. However, the lack of an efficient approach to systemically deliver bioactive NGF into ischemic region hinders its clinical application. In this study, we engineered the exosomes with RVG peptide on the surface for neuron targeting and loaded NGF into exosomes simultaneously, with the resultant exosomes denoted as NGF@Exo^RVG. By systemic administration of NGF@Exo^RVG, NGF was efficiently delivered into ischemic cortex, with a burst release of encapsulated NGF protein and de novo NGF protein translated from the delivered mRNA. Moreover, NGF@Exo^RVG was found to be highly stable for preservation and function efficiently for a long time in vivo. Functional study revealed that the delivered NGF reduced inflammation by reshaping microglia polarization, promoted cell survival, and increased the population of doublecortin-positive cells, a marker of neuroblast. The results of our study suggest the potential therapeutic effects of NGF@Exo^RVG for stroke. Moreover, the strategy proposed in our study may shed light on the clinical application of other neurotrophic factors for central nervous system diseases.

Nanomedicine to target multidrug resistant tumors

Nanomedicine employs nanotechnologies to develop innovative applications, and more specifically nano-objects in the field of human health, through exploitation of the physical, chemical and biological properties of materials at the nanoscale. The use of nanovehicles capable of transporting and releasing the active therapeutic payload into target cells, particularly in the case of cancer or inflammatory diseases, can also enhance diagnosis. Therefore, nanomedicines improve the benefit/risk ratio of drugs by increasing their bioavailability, selectivity, and efficacy in the target tissue, while reducing the necessary doses and hence diminishing untoward toxicity to healthy tissues. Overcoming multidrug resistance (MDR) to antitumor agents is a central goal of cancer research and therapeutics, making it possible to treat these diseases more accurately and effectively. The adaptability of nanomedicines e.g. modulation of their components, surface functionalization, encapsulation of various active therapeutics as well as the possibility of combining several treatments using a single nanoparticle platform, are characteristics which are perfectly poised to address classical chemoresistance, a major obstacle towards curative cancer therapy. In this review, we discuss an assortment of nanomedicines along with those that should be developed in order to surmount cancer MDR; these include exosomes, natural compounds, lipid nanocapsules, prodrug self-assemblies, and gold nanoparticles.

Exosomes as drug delivery vehicle and contributor of resistance to anticancer drugs

Exosomes are small membranous vesicles implicated in intercellular signalling. Through their uncanny ability to carry and deliver donor cellular cargo (biomolecules) to target cells, they exert a profound effect on the regular functioning of healthy cells and play a significant role in pathogenesis and progression of several diseases, including cancer. The composition and number of endogenously circulating exosomes frequently vary, which is often reflective of the pathophysiological status of the cell. Applicability of exosomes derived from normal cells as a drug carrier with or without modifying their intraluminal and surface components are generally tested. Conversely, exosomes also are reported to contribute to resistance towards several anti-cancer therapies. Therefore, it is necessary to carefully evaluate the role of exosomes in cancer progression, resistance and the potential use of exosomes as a delivery vehicle of cancer therapeutics. In this review, we summarize the recent advancements in the exploitation of exosomes as a drug delivery vehicle. We also discuss the role of exosomes in conferring resistance to anti-cancer therapeutics. While this review is focused on cancer, the exosome-based drug delivery and resistance is also applicable to other human diseases.

An engineered exosome for delivering sgRNA:Cas9 ribonucleoprotein complex and genome editing in recipient cells

CRISPR-Cas9 is a versatile genome-editing technology that is a promising gene therapy tactic. However, the delivery of CRISPR-Cas9 is still a major obstacle to its broader clinical application. Here, we confirm that the components of CRISPR-Cas9-sgRNA and Cas9 protein-can be packaged into exosomes, where sgRNA and Cas9 protein exist as a sgRNA:Cas9 ribonucleoprotein complex. Although exosomal CRISPR-Cas9 components can be delivered into recipient cells, they are not adequate to abrogate the target gene in recipient cells. To solve this, we engineered a functionalized exosome (M-CRISPR-Cas9 exosome) that could encapsulate CRISPR-Cas9 components more efficiently. To improve the loading efficiency of Cas9 proteins into exosomes, we artificially engineered exosomes by fusing GFP and GFP nanobody with exosomal membrane protein CD63 and Cas9 protein, respectively. Therefore, Cas9 proteins could be captured selectively and efficiently loaded into exosomes due to the affinity of GFP-GFP nanobody rather than random loading. sgRNA and Cas9 protein exist as a complex in functionalized exosomes and can be delivered into recipient cells. To show the function of modified exosomes-delivered CRISPR-Cas9 components in recipient cells visually, we generated a reporter cell line (A549stop-DsRed) that produced a red fluorescent signal when the stop element was deleted by the sgRNA-guided endonuclease. Using A549stop-DsRed reporter cells, we showed that modified exosomes loaded with CRISPR-Cas9 components abrogated the target gene more efficiently in recipient cells. Our study reports an alternative tactic for CRISPR-Cas9 delivery.

Extracellular Vesicle- and Extracellular Vesicle Mimetics-Based Drug Delivery Systems: New Perspectives, Challenges, and Clinical Developments

Extracellular vesicles (EVs) are small membrane-based nanovesicles naturally released from cells. Extracellular vesicles mimetics (EVMs) are artificial vesicles engineered from cells or in combination with lipid materials, and they mimic certain characteristics of EVs. As such, EVs facilitate intracellular communication by carrying and delivering biological materials, such as proteins, lipids, and nucleic acids, and they have been found to find organ tropism in preclinical studies. Because of their native structure and characteristics, they are considered promising drug carriers for future clinical use. This review outlines the origin and composition of natural EVs and EVM engineering and internalization. It then details different loading approaches, with examples of the drug delivery of therapeutic molecules. In addition, the advantages and disadvantages of loading drugs into EVs or EVMs as a drug delivery system are discussed. Finally, the advantages of EVMs over EVs and the future clinical translation of EVM-based drug delivery platforms are outlined.

Reprogramming extracellular vesicles with engineered proteins

Extracellular vesicles (EVs) have been emerging as a new class of cell-free therapy for the treatment of a variety of diseases, including cancer, tissue injuries, and inflammatory diseases. Reprograming native EVs by genetic engineering and other approaches offers an attractive prospect of extending therapeutic capabilities of EVs beyond their natural functions and properties. In this review article, we survey the state-of-the-art methods of EVs engineering and summarize major therapeutic applications of the reprogrammed EVs.

Ultrasound Assisted Exosomal Delivery of Tissue Responsive mRNA for Enhanced Efficacy and Minimized Off-Target Effects

Exosome-mediated nucleic acids delivery has been emerging as a promising strategy for gene therapy. However, the intrinsic off-target effects due to non-specific uptake of exosomes by other tissues remain the big hurdle for clinical application. In this study, we aimed to enhance the efficacy and minimize the off-target effects by simultaneously encapsulating engineered mRNA translationally activated by tissue-specific microRNA (miRNA) and increasing targeted delivery efficiency via ultrasound-targeted microbubble destruction (UTMD). Briefly, the upstream of interest transcript was engineered to harbor an internal ribosome entry site (IRES) modified with two miRNA recognition sites. In vitro reporter experiments revealed that the engineered mRNA could be encapsulated into exosomes and can be translationally activated by corresponding miRNAs in the recipient cells. By a proof-of-principle in vivo experiment, we encapsulated miR-148a (an adipose relatively specific miRNA)-responsive PGC1α mRNA into exosomes and delivered the exosomes into the adipose tissue with the aid of UTMD. Efficient PGC1α translation was activated in the adipose tissue, together with obvious browning induction. Moreover, there was much lower off-target translation of PGC1 α in lungs and other tissues. Taken together, our study establishes a novel adipose-specific exosome delivery strategy to enhance efficacy and minimize off-target effects simultaneously.

Lipid and polymer mediated CRISPR/Cas9 gene editing

A clustered regularly interspaced short palindromic repeats (CRISPR)/associated protein 9 (CRISPR/Cas9) system is the most widely used tool for gene editing.

Extracellular vesicles in neurodegenerative diseases: Insights and new perspectives

Extracellular vesicles (EVs) are vesicle-like substances released by eukaryotic cells. Based on their origin and size, EVs are mainly divided into exosomes, microvesicles and apoptotic bodies, and they are secreted by eukaryotic cells under physiological and pathological conditions. EVs are enriched with nucleic acids, proteins and other factors. EVs can regulate the function of adjacent and distant cells, and they are even involved in the pathogenesis of diseases. They contain proteins associated with the pathogenesis of neurodegenerative diseases (NDs), such as the α-synuclein (α-syn) and tau proteins, which suggest potential roles for EVs as biomarkers and carriers of drugs and other therapeutic molecules that can cross the blood–brain barrier to treat NDs. In this review, we summarized the function of EVs in the pathogenesis of different NDs and related advances in EVs as diagnostic biomarkers and treatments for diseases.