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

Functionalized extracellular nanovesicles as advanced CRISPR delivery systems

The clustered regularly interspaced short palindromic repeat (CRISPR) system, an emerging tool for genome editing, has garnered significant public interest for its potential in treating genetic diseases. Despite the rapid advancements in CRISPR technology, the progress in developing effective delivery strategies lags, impeding its clinical application. Extracellular nanovesicles (EVs), either in their endogenous forms or with engineered modifications, have emerged as a promising solution for CRISPR delivery. These EVs offer several advantages, including high biocompatibility, biological permeability, negligible immunogenicity, and straightforward production. Herein, we first summarize various types of functional EVs for CRISPR delivery, such as unmodified, modified, engineered virus-like particles (VLPs), and exosome-liposome hybrid vesicles, and examine their distinct intracellular pathways. Then, we outline the cutting-edge techniques for functionalizing extracellular vesicles, involving producer cell engineering, vesicle engineering, and virus-like particle engineering, emphasizing the diverse CRISPR delivery capabilities of these nanovesicles. Lastly, we address the current challenges and propose rational design strategies for their clinical translation, offering future perspectives on the development of functionalized EVs.

Exosome for mRNA delivery: strategies and therapeutic applications

Messenger RNA (mRNA) has emerged as a promising therapeutic molecule with numerous clinical applications in treating central nervous system disorders, tumors, COVID-19, and other diseases. mRNA therapies must be encapsulated into safe, stable, and effective delivery vehicles to preserve the cargo from degradation and prevent immunogenicity. Exosomes have gained growing attention in mRNA delivery because of their good biocompatibility, low immunogenicity, small size, unique capacity to traverse physiological barriers, and cell-specific tropism. Moreover, these exosomes can be engineered to utilize the natural carriers to target specific cells or tissues. This targeted approach will enhance the efficacy and reduce the side effects of mRNAs. However, difficulties such as a lack of consistent and reliable methods for exosome purification and the efficient encapsulation of large mRNAs into exosomes must be addressed. This article outlines current breakthroughs in cell-derived vesicle-mediated mRNA delivery and its biomedical applications.

Exosomes based strategies for cardiovascular diseases: Opportunities and challenges

Exosomes, as nanoscale extracellular vesicles (EVs), are secreted by all types of cells to facilitate intercellular communication in living organisms. After being taken up by neighboring or distant cells, exosomes can alter the expression levels of target genes in recipient cells and thereby affect their pathophysiological outcomes depending on payloads encapsulated therein. The functions and mechanisms of exosomes in cardiovascular diseases have attracted much attention in recent years and are thought to have cardioprotective and regenerative potential. This review summarizes the biogenesis and molecular contents of exosomes and details the roles played by exosomes released from various cells in the progression and recovery of cardiovascular disease. The review also discusses the current status of traditional exosomes in cardiovascular tissue engineering and regenerative medicine, pointing out several limitations in their application. It emphasizes that some of the existing emerging industrial or bioengineering technologies are promising to compensate for these shortcomings, and the combined application of exosomes and biomaterials provides an opportunity for mutual enhancement of their performance. The integration of exosome-based cell-free diagnostic and therapeutic options will contribute to the further development of cardiovascular regenerative medicine.

Engineering Approaches for Exosome Cargo Loading and Targeted Delivery: Biological versus Chemical Perspectives

Exosomes are nanoscale membrane bound vesicles secreted by almost all types of cells. Their unique attributes, such as minimal immunogenicity and compatibility with biological systems, make them novel carriers for drug delivery. These native exosomes harbor proteins, nucleic acids, small molecule compounds, and fluorogenic agents. Moreover, through a combination of chemical and bioengineering methodologies, exosomes are tailored to transport precise therapeutic payloads to designated cells or tissues. In this review, we summarize the strategies for exosome modification and drug loading modalities in engineered exosomes. In addition, we provide an overview of the advances in the use of engineered exosomes for targeted drug delivery. Lastly, we discuss the merits and limitations of chemically engineered versus bioengineered exosome-mediated target therapies. These insights offer additional options for refining engineered exosomes in pharmaceutical development and hold promise for expediting the successful translation of engineered exosomes from the bench to the bedside.

RNA therapeutics in targeting G protein-coupled receptors: Recent advances and challenges

G protein-coupled receptors (GPCRs) are the major targets of existing drugs for a plethora of human diseases and dominate the pharmaceutical market. However, over 50% of the GPCRs remain undruggable. To pursue a breakthrough and overcome this situation, there is significant clinical research for developing RNA-based drugs specifically targeting GPCRs, but none has been approved so far. RNA therapeutics represent a unique and promising approach to selectively targeting previously undruggable targets, including undruggable GPCRs. However, the development of RNA therapeutics faces significant challenges in areas of RNA stability and efficient in vivo delivery. This review presents an overview of the advances in RNA therapeutics and the diverse types of nanoparticle RNA delivery systems. It also describes the potential applications of GPCR-targeted RNA drugs for various human diseases.

Exosome: From biology to drug delivery

In recent years, different advancements have been observed in nanosized drug delivery systems. Factors such as stability, safety and targeting efficiency cause hindrances in the clinical translation of these synthetic nanocarriers. Therefore, researchers employed endogenous nanocarriers like exosomes as drug delivery vehicles that have an inherent ability to target more efficiently after appropriate functionalization and show higher biocompatibility and less immunogenicity and facilitate penetration through the biological barriers more quickly than the other available carriers. Exosomes are biologically derived lipid bilayer-enclosed nanosized extracellular vesicles (size ranges from 30 to 150 nm) secreted from both prokaryotic and eukaryotic cells and appears significantly in the extracellular space. These EVs (extracellular vesicles) can exist in different sources, including mammals, plants and microorganisms. Different advanced techniques have been introduced for the isolation of exosomes to overcome the existing barriers present with conventional methods. Extensive research on the application of exosomes in therapeutic delivery for treating various diseases related to central nervous system, bone, cancer, skin, etc. has been employed. Several studies are on different stages of clinical trials, and many exosomes patents have been registered.

A quick and innovative pipeline for producing chondrocyte-homing peptide-modified extracellular vesicles by three-dimensional dynamic culture of hADSCs spheroids to modulate the fate of remaining ear chondrocytes in the M1 macrophage-infiltrated microenvironment

BACKGROUND

Extracellular vesicles (EVs) derived from human adipose-derived mesenchymal stem cells (hADSCs) have shown great therapeutic potential in plastic and reconstructive surgery. However, the limited production and functional molecule loading of EVs hinder their clinical translation. Traditional two-dimensional culture of hADSCs results in stemness loss and cellular senescence, which is unfavorable for the production and functional molecule loading of EVs. Recent advances in regenerative medicine advocate for the use of three-dimensional culture of hADSCs to produce EVs, as it more accurately simulates their physiological state. Moreover, the successful application of EVs in tissue engineering relies on the targeted delivery of EVs to cells within biomaterial scaffolds.

METHODS AND RESULTS

The hADSCs spheroids and hADSCs gelatin methacrylate (GelMA) microspheres are utilized to produce three-dimensional cultured EVs, corresponding to hADSCs spheroids-EVs and hADSCs microspheres-EVs respectively. hADSCs spheroids-EVs demonstrate excellent production and functional molecule loading compared with hADSCs microspheres-EVs. The upregulation of eight miRNAs (i.e. hsa-miR-486-5p, hsa-miR-423-5p, hsa-miR-92a-3p, hsa-miR-122-5p, hsa-miR-223-3p, hsa-miR-320a, hsa-miR-126-3p, and hsa-miR-25-3p) and the downregulation of hsa-miR-146b-5p within hADSCs spheroids-EVs show the potential of improving the fate of remaining ear chondrocytes and promoting cartilage formation probably through integrated regulatory mechanisms. Additionally, a quick and innovative pipeline is developed for isolating chondrocyte homing peptide-modified EVs (CHP-EVs) from three-dimensional dynamic cultures of hADSCs spheroids. CHP-EVs are produced by genetically fusing a CHP at the N-terminus of the exosomal surface protein LAMP2B. The CHP + LAMP2B-transfected hADSCs spheroids were cultured with wave motion to promote the secretion of CHP-EVs. A harvesting method is used to enable the time-dependent collection of CHP-EVs. The pipeline is easy to set up and quick to use for the isolation of CHP-EVs. Compared with nontagged EVs, CHP-EVs penetrate the biomaterial scaffolds and specifically deliver the therapeutic miRNAs to the remaining ear chondrocytes. Functionally, CHP-EVs show a major effect on promoting cell proliferation, reducing cell apoptosis and enhancing cartilage formation in remaining ear chondrocytes in the M1 macrophage-infiltrated microenvironment.

CONCLUSIONS

In summary, an innovative pipeline is developed to obtain CHP-EVs from three-dimensional dynamic culture of hADSCs spheroids. This pipeline can be customized to increase EVs production and functional molecule loading, which meets the requirements for regulating remaining ear chondrocyte fate in the M1 macrophage-infiltrated microenvironment.

Surface functionalization of exosomes for chondrocyte-targeted siRNA delivery and cartilage regeneration

Osteoarthritis (OA) is the most prevalent degenerative cartilage disease, but no effective treatment is currently available to ameliorate the dysregulation of cartilage catabolism. Cartilage degeneration is closely related to the change in the physiology of chondrocytes: for example, chondrocytes of the OA patients overexpress matrix metallopeptidase 13 (MMP13), a.k.a. collagenase 3, which damages the extracellular matrix (ECM) of the cartilage and deteriorate the disease progression. Inhibiting MMP13 has shown to be beneficial for OA treatments, but delivering therapeutics to the chondrocytes embedded in the dense cartilage is a challenge. Here, we engineered the exosome surface with the cartilage affinity peptide (CAP) through lipid insertion to give chondrocyte-targeting exosomes, CAP-Exo, which was then loaded with siRNA against MMP13 (siMMP13) in the interior to give CAP-Exo/siMMP13. Intra-articular administration of CAP-Exo/siMMP13 reduced the MMP13 level and increased collagen COL2A1 and proteoglycan in cartilage in a rat model of anterior cruciate ligament transection (ACLT)-induced OA. Proteomic analysis showed that CAP-Exo/siMMP13 treatment restored the altered protein levels in the IL-1β-treated chondrocytes. Taken together, a facile exosome engineering method enabled targeted delivery of siRNA to chondrocytes and chondrocyte-specific silencing of MMP13 to attenuate cartilage degeneration.

Therapeutic Applications of Nanomedicine: Recent Developments and Future Perspectives

The concept of nanomedicine has evolved significantly in recent decades, leveraging the unique phenomenon known as the enhanced permeability and retention (EPR) effect. This has facilitated major advancements in targeted drug delivery, imaging, and individualized therapy through the integration of nanotechnology principles into medicine. Numerous nanomedicines have been developed and applied for disease treatment, with a particular focus on cancer therapy. Recently, nanomedicine has been utilized in various advanced fields, including diagnosis, vaccines, immunotherapy, gene delivery, and tissue engineering. Multifunctional nanomedicines facilitate concurrent medication delivery, therapeutic monitoring, and imaging, allowing for immediate responses and personalized treatment plans. This review concerns the major advancement of nanomaterials and their potential applications in the biological and medical fields. Along with this, we also mention the various clinical translations of nanomedicine and the major challenges that nanomedicine is currently facing to overcome the clinical translation barrier.

Unlocking the potential of exosomes: a breakthrough in the theranosis of degenerative orthopaedic diseases

Degenerative orthopaedic diseases pose a notable worldwide public health issue attributable to the global aging population. Conventional medical approaches, encompassing physical therapy, pharmaceutical interventions, and surgical methods, face obstacles in halting or reversing the degenerative process. In recent times, exosome-based therapy has gained widespread acceptance and popularity as an effective treatment for degenerative orthopaedic diseases. This therapeutic approach holds the potential for "cell-free" tissue regeneration. Exosomes, membranous vesicles resulting from the fusion of intracellular multivesicles with the cell membrane, are released into the extracellular matrix. Addressing challenges such as the rapid elimination of natural exosomes in vivo and the limitation of drug concentration can be effectively achieved through various strategies, including engineering modification, gene overexpression modification, and biomaterial binding. This review provides a concise overview of the source, classification, and preparation methods of exosomes, followed by an in-depth analysis of their functions and potential applications. Furthermore, the review explores various strategies for utilizing exosomes in the treatment of degenerative orthopaedic diseases, encompassing engineering modification, gene overexpression, and biomaterial binding. The primary objective is to provide a fresh viewpoint on the utilization of exosomes in addressing bone degenerative conditions and to support the practical application of exosomes in the theranosis of degenerative orthopaedic diseases.

Defining tropism and activity of natural and engineered extracellular vesicles

Extracellular vesicles (EVs) have important roles as mediators of cell-to-cell communication, with physiological functions demonstrated in various in vivo models. Despite advances in our understanding of the biological function of EVs and their potential for use as therapeutics, there are limitations to the clinical approaches for which EVs would be effective. A primary determinant of the biodistribution of EVs is the profile of proteins and other factors on the surface of EVs that define the tropism of EVs in vivo. For example, proteins displayed on the surface of EVs can vary in composition by cell source of the EVs and the microenvironment into which EVs are delivered. In addition, interactions between EVs and recipient cells that determine uptake and endosomal escape in recipient cells affect overall systemic biodistribution. In this review, we discuss the contribution of the EV donor cell and the role of the microenvironment in determining EV tropism and thereby determining the uptake and biological activity of EVs.

Regulation of cargo selection in exosome biogenesis and its biomedical applications in cancer

Extracellular vesicles (EVs), including exosomes, are increasingly recognized as potent mediators of intercellular communication due to their capacity to transport a diverse array of bioactive molecules. They assume vital roles in a wide range of physiological and pathological processes and hold significant promise as emerging disease biomarkers, therapeutic agents, and carriers for drug delivery. Exosomes encompass specific groups of membrane proteins, lipids, nucleic acids, cytosolic proteins, and other signaling molecules within their interior. These cargo molecules dictate targeting specificity and functional roles upon reaching recipient cells. Despite our growing understanding of the significance of exosomes in diverse biological processes, the molecular mechanisms governing the selective sorting and packaging of cargo within exosomes have not been fully elucidated. In this review, we summarize current insights into the molecular mechanisms that regulate the sorting of various molecules into exosomes, the resulting biological functions, and potential clinical applications, with a particular emphasis on their relevance in cancer and other diseases. A comprehensive understanding of the loading processes and mechanisms involved in exosome cargo sorting is essential for uncovering the physiological and pathological roles of exosomes, identifying therapeutic targets, and advancing the clinical development of exosome-based therapeutics.

Targeted exosome-based nanoplatform for new-generation therapeutic strategies

Exosomes, typically 30-150 nm in size, are lipid-bilayered small-membrane vesicles originating in endosomes. Exosome biogenesis is regulated by the coordination of various mechanisms whereby different cargoes (e.g. proteins, nucleic acids, and lipids) are sorted into exosomes. These components endow exosomes with bioregulatory functions related to signal transmission and intercellular communication. Exosomes exhibit substantial potential as drug-delivery nanoplatforms owing to their excellent biocompatibility and low immunogenicity. Proteins, miRNA, siRNA, mRNA, and drugs have been successfully loaded into exosomes, and these exosome-based delivery systems show satisfactory therapeutic effects in different disease models. To enable targeted drug delivery, genetic engineering and chemical modification of the lipid bilayer of exosomes are performed. Stimuli-responsive delivery nanoplatforms designed with appropriate modifications based on various stimuli allow precise control of on-demand drug delivery and can be utilized in clinical treatment. In this review, we summarize the general properties, isolation methods, characterization, biological functions, and the potential role of exosomes in therapeutic delivery systems. Moreover, the effective combination of the intrinsic advantages of exosomes and advanced bioengineering, materials science, and clinical translational technologies are required to accelerate the development of exosome-based delivery nanoplatforms.

Chemically Modified Platforms for Better RNA Therapeutics

RNA-based therapies have catalyzed a revolutionary transformation in the biomedical landscape, offering unprecedented potential in disease prevention and treatment. However, despite their remarkable achievements, these therapies encounter substantial challenges including low stability, susceptibility to degradation by nucleases, and a prominent negative charge, thereby hindering further development. Chemically modified platforms have emerged as a strategic innovation, focusing on precise alterations either on the RNA moieties or their associated delivery vectors. This comprehensive review delves into these platforms, underscoring their significance in augmenting the performance and translational prospects of RNA-based therapeutics. It encompasses an in-depth analysis of various chemically modified delivery platforms that have been instrumental in propelling RNA therapeutics toward clinical utility. Moreover, the review scrutinizes the rationale behind diverse chemical modification techniques aiming at optimizing the therapeutic efficacy of RNA molecules, thereby facilitating robust disease management. Recent empirical studies corroborating the efficacy enhancement of RNA therapeutics through chemical modifications are highlighted. Conclusively, we offer profound insights into the transformative impact of chemical modifications on RNA drugs and delineates prospective trajectories for their future development and clinical integration.

Next-generation biological vector platforms for in vivo delivery of genome editing agents

CRISPR-based genome editing holds promise for addressing genetic disease, infectious disease, and cancer and has rapidly advanced from primary research to clinical trials in recent years. However, the lack of safe and potent in vivo delivery methods for CRISPR components has limited most ongoing clinical trials to ex vivo gene therapy. Effective CRISPR in vivo genome editing necessitates an effective vehicle ensuring target cell transduction while minimizing off-target effects, toxicity, and immune reactions. In this review, we examine promising biological-derived platforms to deliver DNA editing agents in vivo and the engineering thereof, encompassing potent viral-based vehicles, flexible protein nanocages, and mammalian-derived particles.

Cellular Uptake of Engineered Extracellular Vesicles: Biomechanisms, Engineered Strategies, and Disease Treatment

Extracellular vesicles (EVs), lipid-enclosed nanosized membrane vesicles, are regarded as new vehicles and therapeutic agents in intercellular communication. During internal circulation, if EVs are not effectively taken up by recipient cells, they will be cleared as "cellular waste" and unable to deliver therapeutic components. It can be seen that cells uptake EVs are the prerequisite premise for sharing intercellular biological information. However, natural EVs have a low rate of absorption by their recipient cells, off-target delivery, and rapid clearance from circulation, which seriously reduces the utilization rate. Affecting the uptake rate of EVs through engineering technologies is essential for therapeutic applications. Engineering strategies for customizing EV uptake can potentially overcome these limitations and enable desirable therapeutic uses of EVs. In this review, the mechanism and influencing factors of natural EV uptake will be described in detail. Targeting each EV uptake mechanism, the strategies of engineered EVs and their application in diseases will be emphatically discussed. Finally, the future challenges and perspectives of engineered EVs are presented multidimensionally.

Drug Delivery System Approaches for Rheumatoid Arthritis Treatment: A Review

Rheumatoid arthritis (RA) is a chronic autoimmune disease that has traditionally been treated using a variety of pharmacological compounds. However, the effectiveness of these treatments is often limited due to challenges associated with their administration. Oral and parenteral routes of drug delivery are often restricted due to issues such as low bioavailability, rapid metabolism, poor absorption, first-pass effect, and severe side effects. In recent years, nanocarrier-based delivery methods have emerged as a promising alternative for overcoming these challenges. Nanocarriers, including nanoparticles, dendrimers, micelles, nanoemulsions, and stimuli-sensitive carriers, possess unique properties that enable efficient drug delivery and targeted therapy. Using nanocarriers makes it possible to circumvent traditional administration routes' limitations. One of the key advantages of nanocarrier- based delivery is the ability to overcome resistance or intolerance to traditional antirheumatic therapies. Moreover, nanocarriers offer improved drug stability, controlled release kinetics, and enhanced solubility, optimizing the therapeutic effect. They can also protect the encapsulated drug, prolonging its circulation time and facilitating sustained release at the target site. This targeted delivery approach ensures a higher concentration of the therapeutic agent at the site of inflammation, leading to improved therapeutic outcomes. This article explores potential developments in nanotherapeutic regimens for RA while providing a comprehensive summary of current approaches based on novel drug delivery systems. In conclusion, nanocarrier-based drug delivery systems have emerged as a promising solution for improving the treatment of rheumatoid arthritis. Further advancements in nanotechnology hold promise for enhancing the efficacy and safety of RA therapies, offering new hope for patients suffering from this debilitating disease.

CRISPR-Cas9 delivery strategies with engineered extracellular vesicles

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

Selective cargo sorting in stem cell-derived small extracellular vesicles: impact on therapeutic efficacy for intervertebral disc degeneration

BACKGROUND

Growing evidence has suggested the role of stem cell-derived small extracellular vesicles (sEVs) in intervertebral disc degeneration (IVDD). The cargo sorting of sEVs, particularly miRNAs, may be influenced when the donor cell is subjected to oxidative stress. Here, we discovered that miRNAs containing specific motifs are selectively sorted into intraluminal vesicles within mesenchymal stem cells (MSCs) in response to oxidative stress.

METHODS

Analysis of miRNA cargoes in sEVs derived from normal MSCs (C-sEVs) or stressed MSCs (T-sEVs) was conducted using miRNA sequencing. Differential expressed miRNAs in sEVs and the identification of motifs were evaluated through bioinformatics analysis. Protein binding was assessed using immunofluorescent staining and immunoprecipitation analysis. Additionally, RNA pull down and RNA immunoprecipitation (RIP) immunoprecipitation were employed to determine the binding between miRNAs and proteins. The effects of C-sEVs and T-sEVs on IVDD were compared by detecting the expression levels of phenotypic genes in vitro or histological evaluation in vivo.

RESULTS

The sorting process of miRNAs is mediated by the nucleocytoplasmic transport of heterogeneous nuclear ribonucleoproteins, which in turn facilitates the phosphorylation of SNAP25 and promotes the transport and secretion of sEVs. Additionally, CHMP1B plays a role in membrane repair and protects against cell ferroptosis upon oxidative stress, concurrently affecting the release of sEVs. Notably, stem cell-derived sEVs associated with ferroptosis impair the therapeutic efficacy for IVDD. However, the application of engineered sEVs containing a specific miRNA inhibitor exhibits the potential to reinstate the therapeutic efficacy for IVDD both in vitro and in vivo.

CONCLUSIONS

Taken together, our findings shed light on the mechanism of miRNAs sorting into sEVs and offer new insights for the optimization of sEV-based treatments during intervertebral disc regeneration. regeneration.

Exosomes for CRISPR-Cas9 Delivery: The Cutting Edge in Genome Editing

Gene mutation correction was challenging until the discovery of clustered regularly interspaced short palindromic repeats (CRISPR) and CRISPR-associated protein (Cas). CRISPR is a new era for genome modification, and this technology has bypassed the limitations of previous methods such as zinc-finger nuclease and transcription activator-like effector nuclease. Currently, this method is becoming the method of choice for gene-editing purposes, especially therapeutic gene editing in diseases such as cardiovascular, neurological, renal, genetic, optical, and stem cell, as well as blood disorders and muscular degeneration. However, finding the optimum delivery system capable of carrying this large complex persists as the main challenge of this technology. Therefore, it would be ideal if the delivery vehicle could direct the introduction of editing functions to specific cells in a multicellular organism. Exosomes are membrane-bound vesicles with high biocompatibility and low immunogenicity; they offer the best and most reliable way to fill the CRISPR/Cas9 system delivery gap. This review presents the current evidence on the molecular mechanisms and challenges of CRISPR/Cas9-mediated genome modification. Also, the role of CRISPR/Cas9 in the development of treatment and diagnosis of numerous disorders, from malignancies to viral infections, has been discussed. Lastly, the focus is on new advances in exosome-delivery technologies that may play a role in CRISPR/Cas9 delivery for future clinical settings.

Exploring the roles and molecular mechanisms of RNA binding proteins in the sorting of noncoding RNAs into exosomes during tumor progression

BACKGROUND

RNA binding proteins (RBPs) play a role in sorting non-coding RNAs (ncRNAs) into exosomes. These ncRNAs, carried by exosomes, are involved in regulating various aspects of tumor progression, including metastasis, angiogenesis, control of the tumor microenvironment, and drug resistance. Recent studies have emphasized the importance of the RBP-ncRNA-exosome mechanism in tumor regulation.

AIM OF REVIEW

This comprehensive review aims to explore the RBP-ncRNA-exosome mechanism and its influence on tumor development. By understanding this intricate mechanism provides novel insights into tumor regulation and may lead to innovative treatment strategies in the future.

KEY SCIENTIFIC CONCEPTS OF REVIEW

The review discusses the formation of exosomes and the complex relationships among RBPs, ncRNAs, and exosomes. The RBP-ncRNA-exosome mechanism is shown to affect various aspects of tumor biology, including metastasis, multidrug resistance, angiogenesis, the immunosuppressive microenvironment, and tumor progression. Tumor development relies on the transmission of information between cells, with RBPs selectively mediating sorting of ncRNAs into exosomes through various mechanisms, which in turn carry ncRNAs to regulate RBPs. The review also provides an overview of potential therapeutic strategies, such as targeted drug discovery and genetic engineering for modifying therapeutic exosomes, which hold great promise for improving cancer treatment.

Secretome as a Tool to Treat Neurological Conditions: Are We Ready?

Due to their characteristics, mesenchymal stem cells (MSCs) are considered a potential therapy for brain tissue injury or degeneration. Nevertheless, despite the promising results observed, there has been a growing interest in the use of cell-free therapies in regenerative medicine, such as the use of stem cell secretome. This review provides an in-depth compilation of data regarding the secretome composition, protocols used for its preparation, as well as existing information on the impact of secretome administration on various brain conditions, pointing out gaps and highlighting relevant findings. Moreover, due to the ability of MSCs to respond differently depending on their microenvironment, preconditioning of MSCs has been used to modulate their composition and, consequently, their therapeutic potential. The different strategies used to modulate the MSC secretome were also reviewed. Although secretome administration was effective in improving functional impairments, regeneration, neuroprotection, and reducing inflammation in brain tissue, a high variability in secretome preparation and administration was identified, compromising the transposition of preclinical data to clinical studies. Indeed, there are no reports of the use of secretome in clinical trials. Despite the existing limitations and lack of clinical data, secretome administration is a potential tool for the treatment of various diseases that impact the CNS.

Extracellular Vesicles for Drug Delivery in Cancer Treatment

Extracellular vesicles (EVs) are nanoscale vesicles derived from cells that mediate intercellular communication by transporting bioactive molecules. They play significant roles in various physiological and pathological conditions. EVs hold great potential as novel biomarkers of diseases, therapeutic agents, and drug delivery vehicles. Furthermore, EVs as novel drug delivery vehicles have demonstrated significant advantages in preclinical settings. In this review, we discussed the biogenesis and characteristics of EVs and their functions in cancer. We summarize the therapeutic applications of EVs as a natural delivery vehicles in cancer therapy. We highlight the existing challenges, illuminate vital questions, and propose recommendations to effectively address them effectively.

Protein-based delivery systems for RNA delivery

RNA-based therapeutics have emerged as promising approaches to modulate gene expression and generate therapeutic proteins or antigens capable of inducing immune responses to treat a variety of diseases, such as infectious diseases, cancers, immunologic disorders, and genetic disorders. However, the efficient delivery of RNA molecules into cells poses significant challenges due to their large molecular weight, negative charge, and susceptibility to degradation by RNase enzymes. To overcome these obstacles, viral and non-viral vectors have been developed, including lipid nanoparticles, viral vectors, proteins, dendritic macromolecules, among others. Among these carriers, protein-based delivery systems have garnered considerable attention due to their potential to address specific issues associated with nanoparticle-based systems, such as liver accumulation and immunogenicity. This review provides an overview of currently marketed RNA drugs, underscores the significance of RNA delivery vector development, delineates the essential characteristics of an ideal RNA delivery vector, and introduces existing protein carriers for RNA delivery. By offering valuable insights, this review aims to serve as a reference for the future development of protein-based delivery vectors for RNA therapeutics.

Nanotechnology in coronary heart disease

Coronary heart disease (CHD) is one of the major causes of death and disability worldwide, especially in low- and middle-income countries and among older populations. Conventional diagnostic and therapeutic approaches have limitations such as low sensitivity, high cost and side effects. Nanotechnology offers promising alternative strategies for the diagnosis and treatment of CHD by exploiting the unique properties of nanomaterials. In this review, we use bibliometric analysis to identify research hotspots in the application of nanotechnology in CHD and provide a comprehensive overview of the current state of the art. Nanomaterials with enhanced imaging and biosensing capabilities can improve the early detection of CHD through advanced contrast agents and high-resolution imaging techniques. Moreover, nanomaterials can facilitate targeted drug delivery, tissue engineering and modulation of inflammation and oxidative stress, thus addressing multiple aspects of CHD pathophysiology. We discuss the application of nanotechnology in CHD diagnosis (imaging and sensors) and treatment (regulation of macrophages, cardiac repair, anti-oxidative stress), and provide insights into future research directions and clinical translation. This review serves as a valuable resource for researchers and clinicians seeking to harness the potential of nanotechnology in the management of CHD. STATEMENT OF SIGNIFICANCE: Coronary heart disease (CHD) is the one of leading cause of death and disability worldwide. Nanotechnology offers new strategies for diagnosing and treating CHD by exploiting the unique properties of nanomaterials. This review uses bibliometric analysis to uncover research trends in the use of nanotechnology for CHD. We discuss the potential of nanomaterials for early CHD detection through advanced imaging and biosensing, targeted drug delivery, tissue engineering, and modulation of inflammation and oxidative stress. We also offer insights into future research directions and potential clinical applications. This work aims to guide researchers and clinicians in leveraging nanotechnology to improve CHD patient outcomes and quality of life.

Small extracellular vesicles as potential theranostic tools in central nervous system disorders

Small extracellular vesicles(sEVs), a subset of extracellular vesicles with a bilateral membrane structure, contain biological cargoes, such as lipids, nucleic acids, and proteins. sEVs are crucial mediators of intercellular communications in the physiological and pathological processes of the central nervous system. Because of the special structure and complex pathogenesis of the brain, central nervous system disorders are characterized by high mortality and morbidity. Increasing evidence has focused on the potential of sEVs in clinical application for central nervous system disorders. sEVs are emerging as a promising diagnostic and therapeutic tool with high sensitivity, low immunogenicity, superior safety profile, and high transfer efficiency. This review highlighted the development of sEVs in central nervous system disorder clinical application. We also outlined the role of sEVs in central nervous system disorders and discussed the limitations of sEVs in clinical translation.

Extracellular vesicles as a potential delivery platform for CRISPR-Cas based therapy in epithelial ovarian cancer

Ovarian Cancer (OC) is the most common gynecological malignancy and the eighth most diagnosed cancer in females worldwide. Presently, it ranks as the fifth leading cause of cancer-related mortality among patients globally. Major factors contributing to the lethality of OC worldwide include delayed diagnosis, chemotherapy resistance, high metastatic rates, and the heterogeneity of subtypes. Despite continuous efforts to develop novel targeted therapies and chemotherapeutic agents, challenges persist in the form of OC resistance and recurrence. In the last decade, CRISPR-Cas-based genome editing has emerged as a powerful tool for modifying genetic and epigenetic mechanisms, holding potential for treating numerous diseases. However, a significant challenge for therapeutic applications of CRISPR-Cas technology is the absence of an optimal vehicle for delivering CRISPR molecular machinery into targeted cells or tissues. Recently, extracellular vesicles (EVs) have gained traction as potential delivery vehicles for various therapeutic agents. These heterogeneous, membrane-derived vesicles are released by nearly all cells into extracellular spaces. They carry a molecular cargo of proteins and nucleic acids within their intraluminal space, encased by a cholesterol-rich phospholipid bilayer membrane. EVs actively engage in cell-to-cell communication by delivering cargo to both neighboring and distant cells. Their inherent ability to shield molecular cargo from degradation and cross biological barriers positions them ideally for delivering CRISPR-Cas ribonucleoproteins (RNP) to target cells. Furthermore, they exhibit higher biocompatibility, lower immunogenicity, and reduced toxicity compared to classical delivery platforms such as adeno-associated virus, lentiviruses, and synthetic nanoparticles. This review explores the potential of employing different CRISPR-Cas systems to target specific genes in OC, while also discussing various methods for engineering EVs to load CRISPR components and enhance their targeting capabilities.

Engineered Exosomes as Theranostic Platforms for Cancer Treatment

Tremendous progress in nanotechnology and nanomedicine has made a significant positive effect on cancer treatment by integrating multicomponents into a single multifunctional nanosized delivery system for combinatorial therapies. Although numerous nanocarriers developed so far have achieved excellent therapeutic performance in mouse models via elegant integration of chemotherapy, photothermal therapy, photodynamic therapy, sonodynamic therapy, and immunotherapy, their synthetic origin may still cause systemic toxicity, immunogenicity, and preferential detection or elimination by the immune system. Exosomes, endogenous nanosized particles secreted by multiple biological cells, could be absorbed by recipient cells to facilitate intercellular communication and content delivery. Therefore, exosomes have emerged as novel cargo delivery tools and attracted considerable attention for cancer diagnosis and treatment due to their innate stability, biological compatibility, and biomembrane penetration capacity. Exosome-related properties and functions have been well-documented; however, there are few reviews, to our knowledge, with a focus on the combination of exosomes and nanotechnology for the development of exosome-based theranostic platforms. To make a timely review on this hot subject of research, we summarize the basic information, isolation and functionalization methodologies, diagnostic and therapeutic potential of exosomes in various cancers with an emphasis on the description of exosome-related nanomedicine for cancer theranostics. The existing appealing challenges and outlook in exosome clinical translation are finally introduced. Advanced biotechnology and nanotechnology will definitely not only promote the integration of intrinsic advantages of natural nanosized exosomes with traditional synthetic nanomaterials for modulated precise cancer treatment but also contribute to the clinical translations of exosome-based nanomedicine as theranostic nanoplatforms.

Engineered extracellular vesicles in female reproductive disorders

Biologically active and nanoscale extracellular vesicles (EVs) participate in a variety of cellular physiological and pathological processes in a cell-free manner. Unlike cells, EVs not only do not cause acute immune rejection, but are much smaller and have a low risk of tumorigenicity or embolization. Because of their unique advantages, EVs show promise in applications in the diagnosis and treatment of reproductive disorders. As research broadens, engineering strategies for EVs have been developed, and engineering strategies for EVs have substantially improved their application potential while circumventing the defects of natural EVs, driving EVs toward clinical applications. In this paper, we will review the engineering strategies of EVs, as well as their regulatory effects and mechanisms on reproductive disorders (including premature ovarian insufficiency (POI), polycystic ovarian syndrome (PCOS), recurrent spontaneous abortion (RSA), intrauterine adhesion (IUA), and endometriosis (EMS)) and their application prospects. This work provides new ideas for the treatment of female reproductive disorders by engineering EVs.

Standardization Approaches for Extracellular Vesicle Loading with Oligonucleotides and Biologics

Extracellular vesicles (EVs) are widely recognized for their potential as drug delivery systems. EVs are membranous nanoparticles shed from cells. Among their natural features are their ability to shield cargo molecules against degradation and enable their functional internalization into target cells. Especially biological or bio-inspired large molecules (LMs), like nucleic acids, proteins, peptides, and others, may profit from encapsulation in EVs for drug delivery purposes. In the last years, a variety of loading protocols are explored for different LMs. The lack of standardization in the EV drug delivery field has impeded their comparability so far. Currently, the first reporting frameworks and workflows for EV drug loading are proposed. The aim of this review is to summarize these evolving standardization approaches and set recently developed methods into context. This will allow for enhanced comparability of future work on EV drug loading with LMs.

Programming assembly of biomimetic exosomes: An emerging theranostic nanomedicine platform

Exosomes have emerged as a promising cell-free therapeutic approach. However, challenges in large-scale production, quality control, and heterogeneity must be overcome before they can be used clinically. Biomimetic exosomes containing key components of natural exosomes have been assembled through extrusion, artificial synthesis, and liposome fusion to address these limitations. These exosome-mimetics (EMs) possess similar morphology and function but provide higher yields, faster large-scale production, and similar size compared to conventional exosomes. This article provides an overview of the chemical and biological properties of various synthetic exosome systems, including nanovesicles (NVs), EMs, and hybrid exosomes. We highlight recent advances in the production and applications of nanobiotechnology and discuss the advantages, limitations, and potential clinical applications of programming assembly of exosome mimetics.

Engineering exosomes derived from subcutaneous fat MSCs specially promote cartilage repair as miR-199a-3p delivery vehicles in Osteoarthritis

Osteoarthritis (OA) is a degenerative joint disease involving cartilage. Exosomes derived from Mesenchymal stem cells (MSCs) therapy improves articular cartilage repair, but subcutaneous fat (SC) stromal cells derived exosomes (MSCsSC-Exos), especially engineering MSCsSC-Exos for drug delivery have been rarely reported in OA therapy. This objective of this study was to clarify the underlying mechanism of MSCsSC-Exos on cartilage repair and therapy of engineering MSCsSC-Exos for drug delivery in OA. MSCsSC-Exos could ameliorate the pathological severity degree of cartilage via miR-199a-3p, a novel molecular highly enriched in MSCsSC-Exos, which could mediate the mTOR-autophagy pathway in OA rat model. Intra-articular injection of antagomiR-199a-3p dramatically attenuated the protective effect of MSCsSC-Exos-mediated on articular cartilage in vivo. Furthermore, to achieve the superior therapeutic effects of MSCsSC-Exos on injured cartilage, engineering exosomes derived from MSCsSC as the chondrocyte-targeting miR-199a-3p delivery vehicles were investigated in vitro and in vivo. The chondrocyte-binding peptide (CAP) binding MSCsSC-Exos could particularly deliver miR-199a-3p into the chondrocytes in vitro and into deep articular tissues in vivo, then exert the excellent protective effect on injured cartilage in DMM-induced OA mice. As it is feasible to obtain human subcutaneous fat from healthy donors by liposuction operation in clinic, meanwhile engineering MSCsSC-Exos to realize targeted delivery of miR-199a-3p into chondrocytes exerted excellent therapeutic effects in OA animal model in vivo. Through combining MSCsSC-Exos therapy and miRNA therapy via an engineering approach, we develop an efficient MSCsSC-Exos-based strategy for OA therapy and promote the application of targeted-MSCsSC-Exos for drug delivery in the future.

Extracellular Vesicles in Hepatocellular Carcinoma: Progress and Challenges in the Translation from the Laboratory to Clinic

Extracellular vesicles (EVs) play critical roles in intercellular communication by transporting bioactive cargo to recipient cells. EVs have been implicated in a range of physiological and pathological processes, including tumor progression, metastasis, immune modulation, and drug resistance. The objective of this review is to present a thorough overview of recent studies focusing on EVs in hepatocellular carcinoma (HCC), with an emphasis on their potential utility as diagnostic biomarkers as well as therapeutic agents. Initially, we explore the utility of EVs as diagnostic biomarkers for HCC, followed by a discussion of their potential as carriers of therapeutic payloads. Additionally, we delve into the emerging field of therapeutic EVs for modulating tumor immune responses. Through this review, our ultimate aim is to provide a comprehensive understanding of the opportunities and challenges in the clinical translation of EV research in the domain of HCC.

Application of exosome engineering modification in targeted delivery of therapeutic drugs

Cancer is the leading cause of premature death in humans. Scientists have developed several therapeutic drugs for cancer treatment. However, drug delivery faces many problems. First, traditional drugs do not target tumors and are prone to causing significant toxic side effects. Second, suitable drug carriers are essential for improving drug delivery to tumors or circulating cancer cells. Exosomes are natural extracellular vesicles with low immunogenicity and prolonged blood circulation in vivo. These characteristics render exosomes ideal drug carriers. This review highlights the properties of exosomes and mechanisms of exosome biogenesis. It also summarizes the engineering modification methods for enhancing exosome yield, targeting, and drug-loading capacity.

Engineering nanoparticle toolkits for mRNA delivery

The concept of using mRNA to produce its own medicine in situ in the body makes it an ideal drug candidate, holding great potential to revolutionize the way we approach medicine. The unique characteristics of mRNA, as well as its customizable biomedical functions, call for the rational design of delivery systems to protect and transport mRNA molecules. In this review, a nanoparticle toolkit is presented for the development of mRNA-based therapeutics from a drug delivery perspective. Nano-delivery systems derived from either natural systems or chemical synthesis, in the nature of organic or inorganic materials, are summarised. Delivery strategies in controlling the tissue targeting and mRNA release, as well as the role of nanoparticles in building and boosting the activity of mRNA drugs, have also been introduced. In the end, our insights into the clinical and translational development of mRNA nano-drugs are presented.

CRISPR delivery with extracellular vesicles: Promises and challenges

The CRISPR gene editing tool holds great potential for curing genetic disorders. However, the safe, efficient, and specific delivery of the CRISPR/Cas9 components into cells and tissues remains a challenge. While many currently available delivery methods achieve high levels of gene editing effects in vivo, they often result in genotoxicity and immunogenicity. Extracellular vesicles (EVs), which are cell-derived lipid nanoparticles, are capable of transferring protein and nucleic acid cargoes between cells, making them a promising endogenous alternative to synthetic delivery methods. This review provides a comprehensive analysis of the currently available strategies for EV-mediated delivery of CRISPR/Cas9. These strategies include cell-based, passive loading obtained by overexpression of CRISPR/Cas9, active loading involving protein or RNA dimerization, and loading into already purified EVs. All these approaches suggest that EV-based CRISPR/Cas9 delivery is useful for achieving both in vitro and in vivo gene editing. Despite that, substantial variations in cellular uptake and gene editing efficiencies indicate that further improvement and standardization are required for the therapeutic use of EVs as a CRISPR/Cas9 delivery vehicle. These improvements include, but is not limited to, the high-yield purification of EVs, increased loading and release efficiencies, as well as improved tissue- or cell-specific targeting specificities.

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

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

Strategies for Engineering of Extracellular Vesicles

Extracellular vesicles (EVs) are membrane vesicles released by cells into the extracellular space. EVs mediate cell-to-cell communication through local and systemic transportation of biomolecules such as DNA, RNA, transcription factors, cytokines, chemokines, enzymes, lipids, and organelles within the human body. EVs gained a particular interest from cancer biology scientists because of their role in the modulation of the tumor microenvironment through delivering bioactive molecules. In this respect, EVs represent an attractive therapeutic target and a means for drug delivery. The advantages of EVs include their biocompatibility, small size, and low immunogenicity. However, there are several limitations that restrict the widespread use of EVs in therapy, namely, their low specificity and payload capacity. Thus, in order to enhance the therapeutic efficacy and delivery specificity, the surface and composition of extracellular vesicles should be modified accordingly. In this review, we describe various approaches to engineering EVs, and further discuss their advantages and disadvantages to promote the application of EVs in clinical practice.

Function and clinical application of exosome-how to improve tumor immunotherapy?

In recent years, immunotherapy has been increasingly used in clinical practice to treat tumors. However, immunotherapy's efficacy varies between tumor types and patient populations, and long-term drug resistance often occurs during treatment. Therefore, it is essential to explore the molecular mechanisms of immunotherapy to improve its efficacy. In this review, we focus on the significance of tumor-derived exosomes in the clinical treatment of tumors and how modifying these exosomes may enhance immune effectiveness. Specifically, we discuss exosome components, such as RNA, lipids, and proteins, and the role of membrane molecules on exosome surfaces. Additionally, we highlight the importance of engineered exosomes for tumor immunotherapy. Our goal is to propose new strategies to improve the efficacy of tumor immunotherapy.

Targeting miRNA by CRISPR/Cas in cancer: advantages and challenges

Clustered regulatory interspaced short palindromic repeats (CRISPR) has changed biomedical research and provided entirely new models to analyze every aspect of biomedical sciences during the last decade. In the study of cancer, the CRISPR/CRISPR-associated protein (Cas) system opens new avenues into issues that were once unknown in our knowledge of the noncoding genome, tumor heterogeneity, and precision medicines. CRISPR/Cas-based gene-editing technology now allows for the precise and permanent targeting of mutations and provides an opportunity to target small non-coding RNAs such as microRNAs (miRNAs). However, the development of effective and safe cancer gene editing therapy is highly dependent on proper design to be innocuous to normal cells and prevent introducing other abnormalities. This study aims to highlight the cutting-edge approaches in cancer-gene editing therapy based on the CRISPR/Cas technology to target miRNAs in cancer therapy. Furthermore, we highlight the potential challenges in CRISPR/Cas-mediated miRNA gene editing and offer advanced strategies to overcome them.

Extracellular vesicle-based biovectors in chronic wound healing: Biogenesis and delivery approaches

Chronic wounds remain an unresolved medical issue because of major social and therapeutic repercussions that require extensive focus. Recent related theragnostic focuses only on wound management and is not effectively promoting chronic wound healing. The rising number of patients with either under-healing or over-healing wounds highlights the ineffectiveness of current wound-healing treatments, and thus, there is an unmet need to focus on alternative treatments. To cover this gap, extracellular vesicles (EVs), for targeted delivery of therapeutics, are emerging as a potential therapy to treat both acute and persistent wounds. To address these issues, we explore the core biology of EVs, associated pharmacology, comprehension of immunogenic outcomes, and potential for long-term wound treatment with improved effectiveness and their nonacceptable side effects. Additionally, the therapeutic role of EVs in severe wound infections through biogenetic moderation, in combination with biomaterials (functional in nature), as well as drug carriers that can offer opportunities for the development of new treatments for this long-term condition, are also carefully elaborated, with an emphasis on biomaterial-based drug delivery systems. It is observed that exploring difficulties and potential outcomes of clinical translation of EV-based therapeutics for wound management has the potential to be adopted as a future therapy.

Current and prospective strategies for advancing the targeted delivery of CRISPR/Cas system via extracellular vesicles

Extracellular vesicles (EVs) have emerged as a promising platform for gene delivery owing to their natural properties and phenomenal functions, being able to circumvent the significant challenges associated with toxicity, problematic biocompatibility, and immunogenicity of the standard approaches. These features are of particularly interest for targeted delivery of the emerging clustered regularly interspaced short palindromic repeat (CRISPR)/CRISPR-associated (Cas) systems. However, the current efficiency of EV-meditated transport of CRISPR/Cas components remains insufficient due to numerous exogenous and endogenous barriers. Here, we comprehensively reviewed the current status of EV-based CRISPR/Cas delivery systems. In particular, we explored various strategies and methodologies available to potentially improve the loading capacity, safety, stability, targeting, and tracking for EV-based CRISPR/Cas system delivery. Additionally, we hypothesise the future avenues for the development of EV-based delivery systems that could pave the way for novel clinically valuable gene delivery approaches, and may potentially bridge the gap between gene editing technologies and the laboratory/clinical application of gene therapies.

Optogenetic engineered umbilical cord MSC-derived exosomes for remodeling of the immune microenvironment in diabetic wounds and the promotion of tissue repair

BACKGROUND

Angiogenesis and tissue repair in chronic non-healing diabetic wounds remain critical clinical problems. Engineered MSC-derived exosomes have significant potential for the promotion of wound healing. Here, we discuss the effects and mechanisms of eNOS-rich umbilical cord MSC exosomes (UCMSC-exo/eNOS) modified by genetic engineering and optogenetic techniques on diabetic chronic wound repair.

METHODS

Umbilical cord mesenchymal stem cells were engineered to express two recombinant proteins. Large amounts of eNOS were loaded into UCMSC-exo using the EXPLOR system under blue light irradiation. The effects of UCMSC-exo/eNOS on the biological functions of fibroblasts and vascular endothelial cells in vitro were evaluated. Full-thickness skin wounds were constructed on the backs of diabetic mice to assess the role of UCMSC-exo/eNOS in vascular neogenesis and the immune microenvironment, and to explore the related molecular mechanisms.

RESULTS

eNOS was substantially enriched in UCMSCs-exo by endogenous cellular activities under blue light irradiation. UCMSC-exo/eNOS significantly improved the biological functions of cells after high-glucose treatment and reduced the expression of inflammatory factors and apoptosis induced by oxidative stress. In vivo, UCMSC-exo/eNOS significantly improved the rate of wound closure and enhanced vascular neogenesis and matrix remodeling in diabetic mice. UCMSC-exo/eNOS also improved the inflammatory profile at the wound site and modulated the associated immune microenvironment, thus significantly promoting tissue repair.

CONCLUSION

This study provides a novel therapeutic strategy based on engineered stem cell-derived exosomes for the promotion of angiogenesis and tissue repair in chronic diabetic wounds.

Recent Genome-Editing Approaches toward Post-Implanted Fetuses in Mice

Genome editing, as exemplified by the CRISPR/Cas9 system, has recently been employed to effectively generate genetically modified animals and cells for the purpose of gene function analysis and disease model creation. There are at least four ways to induce genome editing in individuals: the first is to perform genome editing at the early preimplantation stage, such as fertilized eggs (zygotes), for the creation of whole genetically modified animals; the second is at post-implanted stages, as exemplified by the mid-gestational stages (E9 to E15), for targeting specific cell populations through in utero injection of viral vectors carrying genome-editing components or that of nonviral vectors carrying genome-editing components and subsequent in utero electroporation; the third is at the mid-gestational stages, as exemplified by tail-vein injection of genome-editing components into the pregnant females through which the genome-editing components can be transmitted to fetal cells via a placenta-blood barrier; and the last is at the newborn or adult stage, as exemplified by facial or tail-vein injection of genome-editing components. Here, we focus on the second and third approaches and will review the latest techniques for various methods concerning gene editing in developing fetuses.

Exploiting the biogenesis of extracellular vesicles for bioengineering and therapeutic cargo loading

Extracellular vesicles (EVs) are gaining increasing attention for diagnostic and therapeutic applications in various diseases. These natural nanoparticles benefit from favorable safety profiles and unique biodistribution capabilities, rendering them attractive drug-delivery modalities over synthetic analogs. However, the widespread use of EVs is limited by technological shortcomings and biological knowledge gaps that fail to unravel their heterogeneity. An in-depth understanding of their biogenesis is crucial to unlocking their full therapeutic potential. Here, we explore how knowledge about EV biogenesis can be exploited for EV bioengineering to load therapeutic protein or nucleic acid cargos into or onto EVs. We summarize more than 75 articles and discuss their findings on the formation and composition of exosomes and microvesicles, revealing multiple pathways that may be stimulation and/or cargo dependent. Our analysis further identifies key regulators of natural EV cargo loading and we discuss how this knowledge is integrated to develop engineered EV biotherapeutics.

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

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

Extracellular vesicle-based delivery of silencing sequences for the treatment of Machado-Joseph disease/spinocerebellar ataxia type 3

Machado-Joseph disease (MJD)/spinocerebellar ataxia type 3 (SCA3) is the most common autosomal dominantly inherited ataxia worldwide. It is caused by an over-repetition of the trinucleotide CAG within the ATXN3 gene, which confers toxic properties to ataxin-3 (ATXN3) species. RNA interference technology has shown promising therapeutic outcomes but still lacks a non-invasive delivery method to the brain. Extracellular vesicles (EVs) emerged as promising delivery vehicles due to their capacity to deliver small nucleic acids, such as microRNAs (miRNAs). miRNAs were found to be enriched into EVs due to specific signal motifs designated as ExoMotifs. In this study, we aimed at investigating whether ExoMotifs would promote the packaging of artificial miRNAs into EVs to be used as non-invasive therapeutic delivery vehicles to treat MJD/SCA3. We found that miRNA-based silencing sequences, associated with ExoMotif GGAG and ribonucleoprotein A2B1 (hnRNPA2B1), retained the capacity to silence mutant ATXN3 (mutATXN3) and were 3-fold enriched into EVs. Bioengineered EVs containing the neuronal targeting peptide RVG on the surface significantly decreased mutATXN3 mRNA in primary cerebellar neurons from MJD YAC 84.2 and in a novel dual-luciferase MJD mouse model upon daily intranasal administration. Altogether, these findings indicate that bioengineered EVs carrying miRNA-based silencing sequences are a promising delivery vehicle for brain therapy.

Leveraging Exosomes as the Next-Generation Bio-Shuttles: The Next Biggest Approach against Th17 Cell Catastrophe

In recent years, the launch of clinical-grade exosomes is rising expeditiously, as they represent a new powerful approach for the delivery of advanced therapies and for diagnostic purposes for various diseases. Exosomes are membrane-bound extracellular vesicles that can act as biological messengers between cells, in the context of health and disease. In comparison to several lab-based drug carriers, exosome exhibits high stability, accommodates diverse cargo loads, elicits low immunogenicity and toxicity, and therefore manifests tremendous perspectives in the development of therapeutics. The efforts made to spur exosomes in drugging the untreatable targets are encouraging. Currently, T helper (Th) 17 cells are considered the most prominent factor in the establishment of autoimmunity and several genetic disorders. Current reports have indicated the importance of targeting the development of Th17 cells and the secretion of its paracrine molecule, interleukin (IL)-17. However, the present-day targeted approaches exhibit drawbacks, such as high cost of production, rapid transformation, poor bioavailability, and importantly, causing opportunistic infections that ultimately hamper their clinical applications. To overcome this hurdle, the potential use of exosomes as vectors seem to be a promising approach for Th17 cell-targeted therapies. With this standpoint, this review discusses this new concept by providing a snapshot of exosome biogenesis, summarizes the current clinical trials of exosomes in several diseases, analyzes the prospect of exosomes as an established drug carrier and delineates the present challenges, with an emphasis on their practical applications in targeting Th17 cells in diseases. We further decode the possible future scope of exosome bioengineering for targeted drug delivery against Th17 cells and its catastrophe.

Bioengineered Mesenchymal-Stromal-Cell-Derived Extracellular Vesicles as an Improved Drug Delivery System: Methods and Applications

Extracellular vesicles (EVs) are cell-derived nano-sized lipid membranous structures that modulate cell-cell communication by transporting a variety of biologically active cellular components. The potential of EVs in delivering functional cargos to targeted cells, their capacity to cross biological barriers, as well as their high modification flexibility, make them promising drug delivery vehicles for cell-free therapies. Mesenchymal stromal cells (MSCs) are known for their great paracrine trophic activity, which is largely sustained by the secretion of EVs. MSC-derived EVs (MSC-EVs) retain important features of the parental cells and can be bioengineered to improve their therapeutic payload and target specificity, demonstrating increased therapeutic potential in numerous pre-clinical animal models, including in the treatment of cancer and several degenerative diseases. Here, we review the fundamentals of EV biology and the bioengineering strategies currently available to maximize the therapeutic value of EVs, focusing on their cargo and surface manipulation. Then, a comprehensive overview of the methods and applications of bioengineered MSC-EVs is presented, while discussing the technical hurdles yet to be addressed before their clinical translation as therapeutic agents.

Potential for Therapeutic-Loaded Exosomes to Ameliorate the Pathogenic Effects of α-Synuclein in Parkinson's Disease

Pathogenic forms of α-synuclein (α-syn) are transferred to and from neurons, astrocytes, and microglia, which spread α-syn pathology in the olfactory bulb and the gut and then throughout the Parkinson's disease (PD) brain and exacerbate neurodegenerative processes. Here, we review attempts to minimize or ameliorate the pathogenic effects of α-syn or deliver therapeutic cargo into the brain. Exosomes (EXs) have several important advantages as carriers of therapeutic agents including an ability to readily cross the blood-brain barrier, the potential for targeted delivery of therapeutic agents, and immune resistance. Diverse cargo can be loaded via various methods, which are reviewed herein, into EXs and delivered into the brain. Genetic modification of EX-producing cells or EXs and chemical modification of EX have emerged as powerful approaches for the targeted delivery of therapeutic agents to treat PD. Thus, EXs hold great promise for the development of next-generation therapeutics for the treatment of PD.