Extracellular vesicle-based therapeutics: natural versus engineered targeting and trafficking

Targeting capabilities of engineered extracellular vesicles for the treatment of neurological diseases

Recent advances in research on extracellular vesicles have significantly enhanced their potential as therapeutic agents for neurological diseases. Owing to their therapeutic properties and ability to cross the blood-brain barrier, extracellular vesicles are recognized as promising drug delivery vehicles for various neurological conditions, including ischemic stroke, traumatic brain injury, neurodegenerative diseases, glioma, and psychosis. However, the clinical application of natural extracellular vesicles is hindered by their limited targeting ability and short clearance from the body. To address these limitations, multiple engineering strategies have been developed to enhance the targeting capabilities of extracellular vesicles, thereby enabling the delivery of therapeutic contents to specific tissues or cells. Therefore, this review aims to highlight the latest advancements in natural and targeting-engineered extracellular vesicles, exploring their applications in treating traumatic brain injury, ischemic stroke, Parkinson's disease, Alzheimer's disease, amyotrophic lateral sclerosis, glioma, and psychosis. Additionally, we summarized recent clinical trials involving extracellular vesicles and discussed the challenges and future prospects of using targeting-engineered extracellular vesicles for drug delivery in treating neurological diseases. This review offers new insights for developing highly targeted therapies in this field.

Isolation and Characterization of Extracellular Vesicles to Activate Retina Regeneration

Mammals do not possess the ability to spontaneously repair or regenerate damaged retinal tissue. In contrast to teleost fish which are capable of retina regeneration through the action of Müller glia, mammals undergo a process of reactive gliosis and scarring that inhibits replacement of lost neurons. Thus, it is important to discover novel methods for stimulating mammalian Müller glia to dedifferentiate and produce progenitor cells that can replace lost retinal neurons. Inducing an endogenous regenerative pathway mediated by Müller glia would provide an attractive alternative to stem cell injections or gene therapy approaches. Extracellular vesicles (EVs) are now recognized to serve as a novel form of cell-cell communication through the transfer of cargo from donor to recipient cells or by the activation of signaling cascades in recipient cells. EVs have been shown to promote proliferation and regeneration raising the possibility that delivery of EVs could be a viable treatment for visual disorders. Here, we provide protocols to isolate EVs for use in retina regeneration experiments.

Nano Plasma Membrane Vesicle-Lipid Nanoparticle Hybrids for Enhanced Gene Delivery and Expression

Lipid nanoparticles (LNPs) have emerged as the leading nonviral nucleic acid (NA) delivery system, gaining widespread attention for their use in COVID-19 vaccines. They are recognized for their efficient NA encapsulation, modifiability, and scalable production. However, LNPs face efficacy and potency limitations due to suboptimal intracellular processing, with endosomal escape efficiencies (ESE) below 2.5%. Additionally, up to 70% of NPs undergo recycling and exocytosis after cellular uptake. In contrast, cell-derived vesicles offer biocompatibility and high-delivery efficacy but are challenging to load with exogenous NAs and to manufacture at large-scale. To leverage the strengths of both systems, a hybrid system is designed by combining cell-derived vesicles, such as nano plasma membrane vesicles (nPMVs), with LNPs through microfluidic mixing and subsequent dialysis. These hybrids demonstrate up to tenfold increase in ESE and an 18-fold rise in reporter gene expression in vitro and in vivo in zebrafish larvae (ZFL) and mice, compared to traditional LNPs. These improvements are linked to their unique physico-chemical properties, composition, and morphology. By incorporating cell-derived vesicles, this strategy streamlines the development process, significantly enhancing the efficacy and potency of gene delivery systems without the need for extensive screening.

Lipid Nanovesicle Platforms for Hepatocellular Carcinoma Precision Medicine Therapeutics: Progress and Perspectives

Hepatocellular carcinoma (HCC) is one of the leading causes of cancer-related mortality globally. HCC is highly heterogenous with diverse etiologies leading to different driver mutations potentiating unique tumor immune microenvironments. Current therapeutic options, including immune checkpoint inhibitors and combinations, have achieved limited objective response rates for the majority of patients. Thus, a precision medicine approach is needed to tailor specific treatment options for molecular subsets of HCC patients. Lipid nanovesicle platforms, either liposome- (synthetic) or extracellular vesicle (natural)-derived present are improved drug delivery vehicles which may be modified to contain specific cargos for targeting specific tumor sites, with a natural affinity for liver with limited toxicity. This mini-review provides updates on the applications of novel lipid nanovesicle-based therapeutics for HCC precision medicine and the challenges associated with translating this therapeutic subclass from preclinical models to the clinic.

A new strategy for drug delivery systems in oral diseases using stem cell-derived extracellular vesicles: review and new perspectives

Extracellular vesicles (EVs) are membrane vesicles derived from cells and serve as an endogenous mechanism for intercellular communication. Since the discovery of their capacity to effectively transfer biological information, their potential as drug delivery vehicles has garnered significant scientific interest. Particularly, EVs derived from mesenchymal cells (MSC-EVs) have emerged as a highly promising method for drug delivery. They can transport bioactive molecules, such as nucleic acids, lipids, and proteins, and possess the ability to modulate immune responses, transmit information, and target specific cells. EVs offer several advantages over conventional drug delivery systems, including their capacity to traverse natural barriers, inherent cell targeting capabilities, and stability in circulation. Compared to their parent cells, EVs exhibit low immunogenicity, ease of storage and transport, and a reduced risk of tumorigenesis. The diagnosis and treatment of oral diseases often involve invasive measures, and MSC-EVs have demonstrated initial efficacy in oral disease treatment. This review explores the application of MSC-EVs in maxillofacial tissue regeneration, periodontitis, temporomandibular joint osteoarthritis, Sjögren's Syndrome, oral cancer, and other oral diseases. Additionally, it outlines potential future directions for the development of MSC-EVs. This review aims to provide a comprehensive understanding of MSC-EVs in oral disease treatment and to stimulate interest in their applications for targeted drug delivery.

The use of nanocarriers in treating Batten disease: A systematic review

The neuronal ceroid lipofuscinoses, commonly known as Batten disease, are a group of lysosomal storage disorders affecting children. There is extensive central nervous system and retinal degeneration, resulting in seizures, vision loss and a progressive cognitive and motor decline. Enzyme replacement and gene therapies are being developed, and mRNA and oligonucleotide therapies are more recently being considered. Overcoming the challenges of the blood-brain barrier and blood-ocular barrier is crucial for effectively targeting the brain and eye, whatever the therapeutic approach. Nanoparticles and extracellular vesicles are small carriers that can encapsulate a cargo and pass through these cell barriers. They have been investigated as drug carriers for other pathologies and could be a promising treatment strategy for Batten disease. Their use in gene, enzyme, or mRNA replacement therapy of all lysosomal storage disorders, including Mucopolysaccharidoses, Niemann-Pick diseases, and Fabry disease, is investigated in this systematic review. Different nanocarriers can efficiently target the lysosome and cross the barriers into the brain and eyes. This supports continued exploration of nanocarriers as potential future treatment options for Batten disease.

A promising therapeutic: Exosome-mediated mitochondrial transplantation

Mitochondrial dysfunction has been identified as a trigger for cellular autophagy dysfunction and programmed cell death. Emerging studies have revealed that, in pathological contexts, intercellular transfer of mitochondria takes place, facilitating the restoration of mitochondrial function, energy metabolism, and immune homeostasis. Extracellular vesicles, membranous structures released by cells, exhibit reduced immunogenicity and enhanced stability during the transfer of mitochondria. Thus, this review provides a concise overview of mitochondrial dysfunction related diseases and the mechanism of mitochondrial dysfunction in diseases progression, and the composition and functions of the extracellular vesicles, along with elucidating the principal mechanisms underlying intercellular mitochondrial transfer. In this article, we will focus on the advancements in both animal models and clinical trials concerning the therapeutic efficacy of extracellular vesicle-mediated mitochondrial transplantation across various systemic diseases in neurodegenerative diseases and cardiovascular diseases. Additionally, the review delves into the multifaceted roles of extracellular vesicle-transplanted mitochondria, encompassing anti-inflammatory actions, promotion of tissue repair, enhancement of cellular function, and modulation of metabolic and immune homeostasis within diverse pathological contexts, aiming to provide novel perspectives for extracellular vesicle transplantation of mitochondria in the treatment of various diseases.

Advanced Enrichment and Separation of Extracellular Vesicles through the Super Absorbent Polymer Nanosieves

Extracellular vesicles (EVs) are promising therapeutic biomaterials capable of transferring their cargo molecules and external drugs to other cells in vivo and contain various biomarkers that can be used in liquid biopsies. The clinical application of EVs requires an efficient EV enrichment system for the large-scale production or high-throughput isolation of EVs from liquid samples, such as culture media, plant juices, and body fluids. However, current EV enrichment methods, such as ultrafiltration and ultracentrifugation, have limited applicability owing to their associated costs, inefficiency, scalability, and centrifugation time. Herein, we describe the development of a nanosieve based on a superabsorbent polymer for selective EV enrichment. The nanosieve absorbs small molecules while expelling large molecules, such as EVs, through the nanosized channels. We successfully concentrated EVs from clinical samples, such as serum and plasma, with superior cost and time efficiencies. The nanosieves did not interact with the EVs during enrichment, allowing the retention of their therapeutic functions. In addition, the nanosieve surface was specifically engineered to provide multifunctionality to effectively promote EV capture from bulk solutions. Overall, our nanosieve-based EV enrichment method is effective, time- and cost-saving, versatile, scalable, and modulable, and is an excellent option for EV production.

The Role of Extracellular Vesicles and Microparticles in Central Nervous System Disorders: Mechanisms, Biomarkers, and Therapeutic Potential

Microscopic, membranous vesicles known as extracellular vesicles (EVs) have been proposed to play a role in the mechanisms underlying central nervous system (CNS) diseases. EVs are secreted by a variety of cells, including myeloid, endothelial, microglial, oligodendroglial, and mesenchymal stem cells (MSCs). Body fluids such as plasma, urine, and cerebrospinal fluid (CSF) contain microparticles (MPs). The detection of MPs in CSF may indicate genetic or environmental susceptibility to conditions such as schizophrenia, schizoaffective disorder, and bipolar disorder. MPs of different origins can exhibit changes in specific biomarkers at various stages of the disease, aiding in the diagnosis and monitoring of neurological conditions. However, understanding the role and clinical applications of MPs is complicated by challenges such as their isolation and dual roles within the CNS. In this review, we discuss the history, characteristics, and roles of MPs in CNS diseases. We also provide practical insights for future research and highlight the challenges that obscure the therapeutic potential of MPs.

Extracellular vesicles as standard-of-care therapy: will fast-tracking the regulatory processes help achieve the goal?

Extracellular Vesicles (EVs) became a focus of clinical research when experimental and pre-clinical studies showed that they mimic their parent cells' regenerative and therapeutic effects and their cargo carries disease-specific diagnostic and prognostic biomarkers. Since the publication of data forms an endpoint of the study, this review specifically focused on the published clinical trials done with EVs. For brevity, this review was restricted to the last 10 years. Unexpectedly, the literature search showed that very few clinical trials assessing the therapeutic applications of EVs were published in this period indicating that they have not reached their desired endpoint. Conversely, most studies showed the potential of EVs present in various biofluids as a promising source of diagnostic and prognostic biomarkers for various diseases, and predictive markers to assess the effectiveness of therapy. This stark difference in the numbers could perhaps be due to the time-consuming regulatory processes involved in the clinical-grade preparation and characterization of EVs, and the determination of their safety and effective dose regimens. One wonders whether fast-tracking regulatory affairs could help accelerate the therapeutic use of EVs. This aspect needs urgent attention.

miRNA packaging into small extracellular vesicles and implications in pain

Extracellular vesicles (EVs) are a heterogenous group of lipid bilayer bound particles naturally released by cells. These vesicles are classified based on their biogenesis pathway and diameter. The overlap in size of exosomes generated from the exosomal pathway and macrovesicles that are pinched off from the surface of the plasma membrane makes it challenging to isolate pure populations. Hence, isolated vesicles that are less than 200 nm are called small extracellular vesicles (sEVs). Extracellular vesicles transport a variety of cargo molecules, and multiple mechanisms govern the packaging of cargo into sEVs. Here, we discuss the current understanding of how miRNAs are targeted into sEVs, including the role of RNA binding proteins and EXOmotif sequences present in miRNAs in sEV loading. Several studies in human pain disorders and rodent models of pain have reported alterations in sEV cargo, including miRNAs. The sorting mechanisms and target regulation of miR-939, a miRNA altered in individuals with complex regional pain syndrome, is discussed in the context of inflammation. We also provide a broad overview of the therapeutic strategies being pursued to utilize sEVs in the clinic and the work needed to further our understanding of EVs to successfully deploy sEVs as a pain therapeutic.

Extracellular vesicle therapeutics for cardiac repair

Extracellular vesicles (EVs) are cell-secreted heterogeneous vesicles that play crucial roles in intercellular communication and disease pathogenesis. Due to their non-tumorigenicity, low immunogenicity, and therapeutic potential, EVs are increasingly used in cardiac repair as cell-free therapy. There exist multiple steps for the design of EV therapies, and each step offers many choices to tune EV properties. Factors such as EV source, cargo, loading methods, routes of administration, surface modification, and biomaterials are comprehensively considered to achieve specific goals. PubMed and Google Scholar were searched in this review, 89 articles related to EV-based cardiac therapy over the past five years (2019 Jan - 2023 Dec) were included, and their key steps in designing EV therapies were counted and analyzed. We aim to provide a comprehensive overview that can serve as a reference guide for researchers to design EV-based cardiac therapies.

Cell-based glycoengineering of extracellular vesicles through precise genome editing

Engineering of extracellular vesicles (EVs) towards more efficient targeting and uptake to specific cells has large potentials for their application as therapeutics. Carbohydrates play key roles in various biological interactions and are essential for EV biology. The extent to which glycan modification of EVs can be achieved through genetic glycoengineering of their parental cells has not been explored yet. Here we introduce targeted glycan modification of EVs through cell-based glycoengineering via modification of various enzymes in the glycosylation machinery. In a "simple cell" strategy, we modified major glycosylation pathways by knocking-out (KO) essential genes for N-glycosylation (MGAT1), O-GalNAc glycosylation (C1GALT1C1), glycosphingolipids (B4GALT5/6), glycosaminoglycans (B4GALT7) and sialylation (GNE) involved in the elongation or biosynthesis of the glycans in HEK293F cells. The gene editing led to corresponding glycan changes on the cells as demonstrated by differential lectin staining. Small EVs (sEVs) isolated from the cells showed overall corresponding glycan changes, but also some unexpected differences to their parental cell including enrichment preference for certain glycan structures and absence of other glycan types. The genetic glycoengineering did not significantly impact sEVs production, size distribution, or syntenin-1 biomarker expression, while a clonal influence on sEVs production yields was observed. Our findings demonstrate the successful implementation of sEVs glycoengineering via genetic modification of the parental cell and a stable source for generation of glycoengineered sEVs. The utilization of glycoengineered sEVs offers a promising opportunity to study the role of glycosylation in EV biology, as well as to facilitate the optimization of sEVs for therapeutic purposes.

Exploring the multiple therapeutic mechanisms and challenges of mesenchymal stem cell-derived exosomes in Alzheimer's disease

Alzheimer's disease (AD) is a severe neurodegenerative disorder, and the current treatment options are limited. Mesenchymal stem cell-derived exosomes (MSC-Exos) have garnered significant attention due to their unique biological properties, showcasing tremendous potential as an acellular alternative therapy for AD. MSC-Exos exhibit excellent biocompatibility and low immunogenicity, enabling them to effectively cross the blood-brain barrier (BBB) and deliver therapeutic molecules directly to target cells. They are highly efficacious in delivering nucleic acid-based drugs. Moreover, the production process of MSC-Exos benefits from a high proliferation capacity and multilineage differentiation potential, allowing for production while maintaining a stable composition. Despite the significant theoretical advantages of MSC-Exos, their clinical use still faces multiple challenges, including cross-contamination during isolation and purification processes, the complexity of their components, and the presence of potential adverse paracrine factors. Future research needs to focus on optimizing separation and purification techniques, enhancing delivery methods to improve therapeutic efficacy, and performing detailed analyses of the components of MSC-Exos. In summary, MSC-Exos hold promise as an effective option for the treatment of AD and other neurodegenerative diseases, driving their clinical research and use in related fields.

Tissue nano-transfection of antimicrobial genes drives bacterial biofilm killing in wounds and is potentially mediated by extracellular vesicles

The emergence of bacteria that are resistant to antibiotics is on track to become a major global health crisis. Therefore, there is an urgent need for new treatment options. Here, we studied the implementation of tissue-nanotransfection (TNT) to treat Staphylococcus aureus-infected wounds by delivering gene cargos that boost the levels of naturally produced antimicrobial peptides. The Cathelicidin Antimicrobial Peptide gene (CAMP), which produces the antimicrobial peptide LL-37, was used as model gene cargo. In vitro evaluation showed successful transfection and an increase in the transcription and translation of CAMP-coding plasmid in mouse primary epithelial cells. Moreover, we found that the extracellular vesicles (EVs) derived from the transfected cells (in vitro and in vivo) carried significantly higher concentrations of CAMP transcripts and LL-37 peptide compared to control EVs, possibly mediating the trafficking of the antimicrobial contents to other neighboring cells. The TNT platform was then used in vivo on an excisional wound model in mice to nanotransfect the CAMP-coding plasmid on the edge of infected wounds. After 4 days of daily treatment, we observed a significant decrease in the bacterial load in the CAMP-treated group compared to the sham group. Moreover, histological analysis and bacterial load quantification also revealed that TNT of CAMP on S. aureus-infected wounds was effective in treating biofilm progression by reducing the bacterial load. Lastly, we observed a significant increase in macrophage recruitment to the infected tissue, a robust increase in vascularization, as well as and an increased expression of IL10 and Fli1. Our results demonstrate that TNT-based delivery of gene cargos coding for antimicrobial compounds to the wound is a promising approach for combating biofilm infections in wounds.

Beta cell extracellular vesicle PD-L1 as a novel regulator of CD8+ T cell activity and biomarker during the evolution of type 1 diabetes

AIMS/HYPOTHESIS

Surviving beta cells in type 1 diabetes respond to inflammation by upregulating programmed death-ligand 1 (PD-L1) to engage immune cell programmed death protein 1 (PD-1) and limit destruction by self-reactive immune cells. Extracellular vesicles (EVs) and their cargo can serve as biomarkers of beta cell health and contribute to islet intercellular communication. We hypothesised that the inflammatory milieu of type 1 diabetes increases PD-L1 in beta cell EV cargo and that EV PD-L1 may protect beta cells against immune-mediated cell death.

METHODS

Beta cell lines and human islets were treated with proinflammatory cytokines to model the proinflammatory type 1 diabetes microenvironment. EVs were isolated using ultracentrifugation or size exclusion chromatography and analysed via immunoblot, flow cytometry and ELISA. EV PD-L1 binding to PD-1 was assessed using a competitive binding assay and in vitro functional assays testing the ability of EV PD-L1 to inhibit NOD CD8+ T cells. Plasma EV and soluble PD-L1 were assayed in the plasma of islet autoantibody-positive (Ab+) individuals or individuals with recent-onset type 1 diabetes and compared with levels in non-diabetic control individuals.

RESULTS

PD-L1 protein co-localised with tetraspanin-associated proteins intracellularly and was detected on the surface of beta cell EVs. Treatment with IFN-α or IFN-γ for 24 h induced a twofold increase in EV PD-L1 cargo without a corresponding increase in the number of EVs. IFN exposure predominantly increased PD-L1 expression on the surface of beta cell EVs and beta cell EV PD-L1 showed a dose-dependent capacity to bind PD-1. Functional experiments demonstrated specific effects of beta cell EV PD-L1 to suppress proliferation and cytotoxicity of murine CD8+ T cells. Plasma EV PD-L1 levels were increased in Ab+individuals, particularly in those positive for a single autoantibody. Additionally, in Ab+ individuals or those who had type 1 diabetes, but not in control individuals, plasma EV PD-L1 positively correlated with circulating C-peptide, suggesting that higher EV PD-L1 could be protective for residual beta cell function.

CONCLUSIONS/INTERPRETATION

IFN exposure increases PD-L1 on the beta cell EV surface. Beta cell EV PD-L1 binds PD1 and inhibits CD8+ T cell proliferation and cytotoxicity. Circulating EV PD-L1 is higher in Ab+ individuals than in control individuals. Circulating EV PD-L1 levels correlate with residual C-peptide at different stages in type 1 diabetes progression. These findings suggest that EV PD-L1 could contribute to heterogeneity in type 1 diabetes progression and residual beta cell function and raise the possibility that EV PD-L1 could be exploited as a means to inhibit immune-mediated beta cell death.

Organoids and organoid extracellular vesicles-based disease treatment strategies

Organoids are "mini-organs" that self-organize and differentiate from stem cells under in vitro 3D culture conditions, mimicking the spatial structure and function of tissues in vivo. Extracellular vesicles (EVs) are nanoscale phospholipid bilayer vesicles secreted by living cells, rich in bioactive molecules, with excellent biocompatibility and low immunogenicity. Compared to EVs, organoid-derived EVs (OEVs) exhibit higher yield and enhanced biological functions. Organoids possess stem cell characteristics, and OEVs are capable of delivering active substances, making both highly promising for medical applications. In this review, we provide an overview of the fundamental biological principles of organoids and OEVs, and discuss their current applications in disease treatment. We then focus on the differences between OEVs and traditional EVs. Subsequently, we present methods for the engineering modification of OEVs. Finally, we critically summarize the advantages and challenges of organoids and OEVs. In conclusion, we believe that a deeper understanding of organoids and OEVs will provide innovative solutions to complex diseases.

Engineered exosome therapeutics for neurodegenerative diseases

An increase in life expectancy comes with a higher risk for age-related neurological and cognitive dysfunctions. Given the psycho-socioeconomic burden due to unhealthy aging in the coming decades, the United Nations has declared 2021-2030 as a decade of healthy aging. In this line, multipotent mesenchymal stromal cell-based therapeutics received special interest from the research community. Based on decades of research on cell therapy, a consensus has emerged that the therapeutic effects of cell therapy are due to the paracrine mechanisms rather than cell replacement. Exosomes, a constituent of the secretome, are nano-sized vesicles that have been a focus of intense research in recent years as a possible therapeutic agent or as a cargo to deliver drugs of interest into the central nervous system to induce neurogenesis, reduce neuroinflammation, confer neuroregeneration/neuroprotection, and improve cognitive and motor functions. In this review, we have discussed the neuroprotective properties of exosomes derived from adult mesenchymal stem cells, with a special focus on the role of exosomal miRNAs. We also reviewed various strategies to improve exosome production and their content for better therapeutic effects. Further, we discussed the utilization of ectomesenchymal stem cells like dental pulp stem cells and their exosomes in treating neurodegenerative diseases.

The impact of exosomes on bone health: A focus on osteoporosis

Osteoporosis is a widespread chronic condition. Although standard treatments are generally effective, they are frequently constrained by side effects and the risk of developing drug resistance. A promising area of research is the investigation of extracellular vesicles (EVs), including exosomes, microvesicles, and apoptotic bodies, which play a crucial role in bone metabolism. Exosomes, in particular, have shown significant potential in both the diagnosis and treatment of osteoporosis. EVs derived from osteoclasts, osteoblasts, mesenchymal stem cells, and other sources can influence bone metabolism, while exosomes from inflammatory and tumor cells may exacerbate bone loss, highlighting their dual role in osteoporosis pathology. This review offers a comprehensive overview of EV biogenesis, composition, and function in osteoporosis, focusing on their diagnostic and therapeutic potential. We examine the roles of various types of EVs and their cargo-proteins, RNAs, and lipids-in bone metabolism. Additionally, we explore the emerging applications of EVs as biomarkers and therapeutic agents, emphasizing the need for further research to address current challenges and enhance EV-based strategies for managing osteoporosis.

Mechanisms of extracellular vesicle uptake and implications for the design of cancer therapeutics

The translation of pre-clinical anti-cancer therapies to regulatory approval has been promising, but slower than hoped. While innovative and effective treatments continue to achieve or seek approval, setbacks are often attributed to a lack of efficacy, failure to achieve clinical endpoints, and dose-limiting toxicities. Successful efforts have been characterized by the development of therapeutics designed to specifically deliver optimal and effective dosing to tumour cells while minimizing off-target toxicity. Much effort has been devoted to the rational design and application of synthetic nanoparticles to serve as targeted therapeutic delivery vehicles. Several challenges to the successful application of this modality as delivery vehicles include the induction of a protracted immune response that results in their rapid systemic clearance, manufacturing cost, lack of stability, and their biocompatibility. Extracellular vesicles (EVs) are a heterogeneous class of endogenous biologically produced lipid bilayer nanoparticles that mediate intercellular communication by carrying bioactive macromolecules capable of modifying cellular phenotypes to local and distant cells. By genetic, chemical, or metabolic methods, extracellular vesicles (EVs) can be engineered to display targeting moieties on their surface while transporting specific cargo to modulate pathological processes following uptake by target cell populations. This review will survey the types of EVs, their composition and cargoes, strategies employed to increase their targeting, uptake, and cargo release, and their potential as targeted anti-cancer therapeutic delivery vehicles.

Low pinocytic brain endothelial cells primarily utilize membrane fusion to internalize extracellular vesicles

Extracellular vesicles (EVs) are an emerging class of drug carriers and are primarily reported to be internalized into recipient cells via a combination of endocytic routes such as clathrin-mediated, caveolae-mediated and macropinocytosis pathways. In this work, (1) we investigated potential effects of homotypic vs. heterotypic interactions by studying the cellular uptake of homologous EVs (EV donor cells and recipient cells of the same type) vs. heterologous EVs (EV donor cells and recipient cells of different types) and (2) determined the route of EV internalization into low pinocytic/hard-to-deliver cell models such as brain endothelial cells (BECs). Homotypic interactions led to a greater extent of uptake into the recipient BECs compared to heterotypic interactions. However, we did not see a complete reduction in EV uptake into recipient BECs when endocytic pathways were blocked using pharmacological inhibitors and our findings from a R18-based fusion assay suggest that EVs primarily use membrane fusion to enter low-pinocytic recipient BECs instead of relying on endocytosis. Lipophilic PKH67 dye-labeled EVs but not intravesicular esterase-activated calcein ester-labeled EVs severely reduced particle uptake into BECs while phagocytic macrophages internalized EVs labeled with both dyes to comparable extents. Our results also highlight the importance of carefully choosing labeling dye chemistry to study EV uptake, especially in the case of low pinocytic cells such as BECs.

Circulating Extracellular Vesicles: An Effective Biomarker for Cancer Progression

Extracellular vesicles (EVs), the ubiquitous part of human biology, represent a small heterogenous, membrane-enclosed body that contains a diverse payload including genetic materials in the form of DNA, RNAs, small non-coding RNAs, etc. mostly mirroring their source of origin. Since, a vast majority of research has been conducted on how nucleic acids, proteins, lipids, and metabolites, associated with EVs can be effectively utilized to identify disease progression and therapeutic responses in cancer patients, EVs are increasingly being touted as valuable and reliable identifiers of cancer biomarkers in liquid biopsies. However, the lack of comprehensive clinical validation and effective standardization protocols severely limits its applications beyond the laboratories. The present review focuses on understanding the role of circulating EVs in different cancers and how they could potentially be treated as cancer biomarkers, typically due to the presence of bioactive molecules such as small non-coding RNAs, RNAs, DNA, proteins, etc., and their utilization for fine-tuning therapies. Here, we provide a brief general biology of EVs including their classification and subsequently discuss the source of circulatory EVs, the role of their associated payload as biomarkers, and how different cancers affect the level of circulatory EVs population.

Extracellular vesicles versus lipid nanoparticles for the delivery of nucleic acids

Extracellular vesicles (EVs) are increasingly investigated for delivering nucleic acid (NA) therapeutics, leveraging their natural role in transporting NA and protein-based cargo in cell-to-cell signaling. Their synthetic counterparts, lipid nanoparticles (LNPs), have been developed over the past decades as NA carriers, culminating in the approval of several marketed formulations such as patisiran/Onpattro® and the mRNA-1273/BNT162 COVID-19 vaccines. The success of LNPs has sparked efforts to develop innovative technologies to target extrahepatic organs, and to deliver novel therapeutic modalities, such as tools for in vivo gene editing. Fueled by the recent advancements in both fields, this review aims to provide a comprehensive overview of the basic characteristics of EV and LNP-based NA delivery systems, from EV biogenesis to structural properties of LNPs. It addresses the primary challenges encountered in utilizing these nanocarriers from a drug formulation and delivery perspective. Additionally, biodistribution profiles, in vitro and in vivo transfection outcomes, as well as their status in clinical trials are compared. Overall, this review provides insights into promising research avenues and potential dead ends for EV and LNP-based NA delivery systems.

Cellular Membrane-Derived Nanovesicles Expressing hCD64 for Targeting Prostate Cancer

Extracellular vesicles are ideal therapeutic potentiators for various diseases. However, they commonly lack targeting capability and are rapidly cleared by phagocytes. This requires appropriate administration at high doses, which can lead to toxic and adverse reactions. To overcome these limitations, we developed bleb nanovesicles containing human Fcγ receptor I (hCD64), known for their strong affinity to monomeric IgG. In this study, we focused on prostate cancer, which has a specific membrane antigen. We have utilized the hCD64-expressing bleb nanovesicles attaching anti-prostate-specific membrane antigen (PSMA) antibodies and confirmed their targeting ability in PSMA-related cell lines and prostate cancer xenograft models. Our findings underscore the promising potential of nanovesicle Fcγ receptor-IgG as a platform for cancer diagnosis and therapy systems, inspiring further research.

Brain incoming call from glia during neuroinflammation: Roles of extracellular vesicles

The functionality of the central nervous system (CNS) relies on the connection, integration, and the exchange of information among neural cells. The crosstalk among glial cells and neurons is pivotal for a series of neural functions, such as development of the nervous system, electric conduction, synaptic transmission, neural circuit establishment, and brain homeostasis. Glial cells are crucial players in the maintenance of brain functionality in physiological and disease conditions. Neuroinflammation is a common pathological process in various brain disorders, such as neurodegenerative diseases, and infections. Glial cells, including astrocytes, microglia, and oligodendrocytes, are the main mediators of neuroinflammation, as they can sense and respond to brain insults by releasing pro-inflammatory or anti-inflammatory factors. Recent evidence indicates that extracellular vesicles (EVs) are pivotal players in the intercellular communication that underlies physiological and pathological processes. In particular, glia-derived EVs play relevant roles in modulating neuroinflammation, either by promoting or inhibiting the activation of glial cells and neurons, or by facilitating the clearance or propagation of pathogenic proteins. The involvement of EVs in neurodegenerative diseases such as Alzheimer's Disease (AD), Parkinson's Disease (PD), Huntington's Disease (HD), and Multiple Sclerosis (MS)- which share hallmarks such as neuroinflammation and oxidative stress to DNA damage, alterations in neurotrophin levels, mitochondrial impairment, and altered protein dynamics- will be dissected, showing how EVs act as pivotal cell-cell mediators of toxic stimuli, thereby propagating degeneration and cell death signaling. Thus, this review focuses on the EVs secreted by microglia, astrocytes, oligodendrocytes and in neuroinflammatory conditions, emphasizing on their effects on neurons and on central nervous system functions, considering both their beneficial and detrimental effects.

Emerging role and translational potential of small extracellular vesicles in neuroscience

Small extracellular vesicles (sEV) are endogenous lipid-bound membrane vesicles secreted by both prokaryotic and eukaryotic cells into the extracellular environment, performs several biological functions such as cell-cell communication, transfer of proteins, mRNA, and ncRNA to target cells in distant sites. Due to their role in molecular pathogenesis and its potential to deliver biological cargo to target cells, it has become a prominent area of interest in recent research in the field of Neuroscience. However, their role in neurological disorders, like neurodegenerative diseases is more complex and still unaddressed. Thus, this review focuses on the role of sEV in neurodegenerative and neurodevelopmental diseases, including their biogenesis, classification, and pathogenesis, with translational advantages and limitations in the area of neurobiology.

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.

Enhanced Extracellular Vesicle Cargo Loading via microRNA Biogenesis Pathway Modulation

Extracellular vesicles (EVs) are physiological vectors for the intercellular transport of a variety of molecules. Among these, small RNAs, and especially microRNAs (miRNAs), have been identified as prevalent components, and there has thus been a robust investigation of EVs for therapeutic miRNAs delivery. However, intrinsic levels of EV-associated miRNAs are generally too low to enable efficient and effective therapeutic outcomes. We hypothesized that miRNA localization to EVs could be improved by limiting competing interactions that occur throughout the miRNA biogenesis process. Using miR-146a-5p as a model, modulation of transcription, nuclear export, and enzymatic cleavage steps of miRNA biogenesis were tested for impact on EV miRNA loading. Working in HEK293T cells, various alterations in the EV biogenesis pathway were shown to impact miRNA localization to EVs. The system was then applied in induced pluripotent stem cells (iPSCs), a more promising substrate for therapeutic EV production, and EVs were separated and assessed for anti-inflammatory efficacy in vitro and in a murine colitis model, where the preservation of function was validated. Overall, the results highlight necessary considerations when designing a cell culture system for the devoted production of miRNA-loaded EVs.

Simultaneous Protein and RNA Analysis in Single Extracellular Vesicles, Including Viruses

The individual detection of human immunodeficiency virus (HIV) virions and resolution from extracellular vesicles (EVs) during analysis is a difficult challenge. Infectious enveloped virions and nonviral EVs are released simultaneously by HIV-infected host cells, in addition to hybrid viral EVs containing combinations of HIV and host components but lacking replicative ability. Complicating the issue, EVs and enveloped virions are both delimited by a lipid bilayer and share similar size and density. The feature that distinguishes infectious virions from host and hybrid EVs is the HIV genomic RNA (gRNA), which allows the virus to replicate. Single-particle analysis techniques, which provide snapshots of single biological nanoparticles, could resolve infectious virions from EVs. However, current single-particle analysis techniques focus mainly on protein detection, which fail to resolve hybrid EVs from infectious virions. A method to simultaneously detect viral protein and internal gRNA in the same particle would allow resolution of infectious HIV from EVs and noninfectious virions. Here, we introduce SPIRFISH, a high-throughput method for single-particle protein and RNA analysis, combining single particle interferometric reflectance imaging sensor with single-molecule fluorescence in situ hybridization. Using SPIRFISH, we detect HIV-1 envelope protein gp120 and genomic RNA within single infectious virions, allowing resolution against EV background and noninfectious virions. We further show that SPIRFISH can be used to detect specific RNAs within EVs. This may have major utility for EV therapeutics, which are increasingly focused on EV-mediated RNA delivery. SPIRFISH should enable single particle analysis of a broad class of RNA-containing nanoparticles.

Engineering extracellular vesicles for diagnosis and therapy

Extracellular vesicle (EV)-based therapeutics have gained substantial interest in the areas of drug delivery, immunotherapy, and regenerative medicine. However, the clinical translation of EVs has been slowed due to limited yields and functional heterogeneity, as well as inadequate targeting. Engineering EVs to modify their inherent function and endow them with additional functions has the potential to advance the clinical translation of EV applications. Bio-orthogonal click chemistry is an engineering approach that modifies EVs in a controlled, specific, and targeted way without compromising their intrinsic structure. Here, we provide an overview of bio-orthogonal labeling approaches involved in EV engineering. We also present the isolation methods of bio-orthogonally labeled vesicles using magnetic beads, microfluidics, and microarray chip technologies. We highlight the in vivo applications of bio-orthogonal labeling EVs for diagnosis and therapy, especially the exciting potential of bio-orthogonal glycometabolic engineered EVs for targeted therapies.

Special Issue: Nanotherapeutics in Women's Health Emerging Nanotechnologies for Triple-Negative Breast Cancer Treatment

Breast cancer appears as the major cause of cancer-related deaths in women, with more than 2 260 000 cases reported worldwide in 2020, resulting in 684 996 deaths. Triple-negative breast cancer (TNBC), characterized by the absence of estrogen, progesterone, and human epidermal growth factor type 2 receptors, represents ≈20% of all breast cancers. TNBC has a highly aggressive clinical course and is more prevalent in younger women. The standard therapy for advanced TNBC is chemotherapy, but responses are often short-lived, with high rate of relapse. The lack of therapeutic targets and the limited therapeutic options confer to individuals suffering from TNBC the poorest prognosis among breast cancer patients, remaining a major clinical challenge. In recent years, advances in cancer nanomedicine provided innovative therapeutic options, as nanoformulations play an important role in overcoming the shortcomings left by conventional therapies: payload degradation and its low solubility, stability, and circulating half-life, and difficulties regarding biodistribution due to physiological and biological barriers. In this integrative review, the recent advances in the nanomedicine field for TNBC treatment, including the novel nanoparticle-, exosome-, and hybrid-based therapeutic formulations are summarized and their drawbacks and challenges are discussed for future clinical applications.

Integrated MicroRNA-mRNA Analyses of the Osteogenic Differentiation of Human Dental Pulp Stem Cells by a Helioxanthin Derivative

Dental pulp stem cells (DPSCs) demonstrate high proliferative and multilineage differentiation potential. As previously reported, the helioxanthin derivative 4-(4-methoxyphenyl)pyrido[40,30:4,5]thieno[2,3-b]pyridine-2-carboxamide (TH) has been demonstrated to induce the osteogenic differentiation of DPSCs. However, the mechanism of osteogenesis induced by TH in DPSCs remains unknown. The objective of this study was to identify functional extracellular vesicle (EV) microRNAs (miRNAs), and the principal genes involved in the TH-induced osteogenesis of DPSCs. DPSCs were derived from dental pulp extracted from the third molars of three healthy subjects, and were cultured with or without TH. miRNAs were extracted from DPSC-derived EVs. The gene expression patterns of mRNA and miRNA were compared using RNA-Seq and miRNA-Seq. To investigate miRNA/mRNA interacting networks, functional analyses were performed by Ingenuity Pathway Analysis. Alkaline phosphatase (ALP) staining demonstrated that treatment with TH resulted in enhanced ALP activity in DPSCs after 7 days. The expression levels of ALP and type 1 collagen alpha 1 were significantly higher in TH-induced DPSCs on day 7. RNA-Seq and miRNA-Seq analyses identified 869 differentially expressed genes (DEGs) and 18 miRNA-DEGs. Gene Ontology analysis of the mRNA-Seq results showed that TH induced several biological activities associated with signal transduction, cell adhesion, and cell differentiation. Integrated miRNA-mRNA analyses showed that these miRNAs contain the targeting information of 277 mRNAs of the DEGs. Among them, 17 target genes known to be involved in the differentiation of osteoblasts, and 24 target genes known to be involved in the differentiation of bone cells were identified. Quantitative real-time PCR showed that WNT5a expression in DPSCs was upregulated by 48 h of TH treatment. Upstream regulator analysis indicated that WNT3a, FOS, and RAC1 may be responsible for gene expression changes in DPSCs after TH treatment. EV miRNA regulatory networks might play crucial roles in TH-induced osteogenic differentiation of DPSCs. Our results presented herein offer valuable insights that will facilitate further research into the mechanism of osteogenesis of DPSCs, which is expected to lead to the clinical application of TH-induced DPSCs for bone regeneration. Furthermore, EVs derived from TH-induced DPSCs might be useful as therapeutic tools for bone defects.

An in-depth exploration of the multifaceted roles of EVs in the context of pathogenic single-cell microorganisms

SUMMARYExtracellular vesicles (EVs) have been recognized throughout scientific communities as potential vehicles of intercellular communication in both eukaryotes and prokaryotes, thereby influencing various physiological and pathological functions of both parent and recipient cells. This review provides an in-depth exploration of the multifaceted roles of EVs in the context of bacteria and protozoan parasite EVs, shedding light on their contributions to physiological processes and disease pathogenesis. These studies highlight EVs as a conserved mechanism of cellular communication, which may lead us to important breakthroughs in our understanding of infection, mechanisms of pathogenesis, and as indicators of disease. Furthermore, EVs are involved in host-microbe interactions, offering insights into the strategies employed by bacteria and protozoan parasites to modulate host responses, evade the immune system, and establish infections.

Nanogene editing drug delivery systems in the treatment of liver fibrosis

Liver fibrosis is a group of diseases that seriously affect the health of the world's population. Despite significant progress in understanding the mechanisms of liver fibrogenesis, the technologies and drugs used to treat liver fibrosis have limited efficacy. As a revolutionary genetic tool, gene editing technology brings new hope for treating liver fibrosis. Combining nano-delivery systems with gene editing tools to achieve precise delivery and efficient expression of gene editing tools that can be used to treat liver fibrosis has become a rapidly developing field. This review provides a comprehensive overview of the principles and methods of gene editing technology and commonly used gene editing targets for liver fibrosis. We also discuss recent advances in common gene editing delivery vehicles and nano-delivery formulations in liver fibrosis research. Although gene editing technology has potential advantages in liver fibrosis, it still faces some challenges regarding delivery efficiency, specificity, and safety. Future studies need to address these issues further to explore the potential and application of liver fibrosis technologies in treating liver fibrosis.

The complexity of extracellular vesicles: Bridging the gap between cellular communication and neuropathology

Brain-derived extracellular vesicles (EVs) serve a prominent role in maintaining homeostasis and contributing to pathology in health and disease. This review establishes a crucial link between physiological processes leading to EV biogenesis and their impacts on disease. EVs are involved in the clearance and transport of proteins and nucleic acids, responding to changes in cellular processes associated with neurodegeneration, including autophagic disruption, organellar dysfunction, aging, and other cell stresses. In neurodegenerative disorders (e.g., Alzheimer's disease, Parkinson's disease, etc.), EVs contribute to the spread of pathological proteins like amyloid β, tau, ɑ-synuclein, prions, and TDP-43, exacerbating neurodegeneration and accelerating disease progression. Despite evidence for both neuropathological and neuroprotective effects of EVs, the mechanistic switch between their physiological and pathological functions remains elusive, warranting further research into their involvement in neurodegenerative disease. Moreover, owing to their innate ability to traverse the blood-brain barrier and their ubiquitous nature, EVs emerge as promising candidates for novel diagnostic and therapeutic strategies. The review uniquely positions itself at the intersection of EV cell biology, neurophysiology, and neuropathology, offering insights into the diverse biological roles of EVs in health and disease.

Vascularized platforms for investigating cell communication via extracellular vesicles

The vascular network plays an essential role in the maintenance of all organs in the body via the regulated delivery of oxygen and nutrients, as well as tissue communication via the transfer of various biological signaling molecules. It also serves as a route for drug administration and affects pharmacokinetics. Due to this importance, engineers have sought to create physiologically relevant and reproducible vascular systems in tissue, considering cell-cell and extracellular matrix interaction with structural and physical conditions in the microenvironment. Extracellular vesicles (EVs) have recently emerged as important carriers for transferring proteins and genetic material between cells and organs, as well as for drug delivery. Vascularized platforms can be an ideal system for studying interactions between blood vessels and EVs, which are crucial for understanding EV-mediated substance transfer in various biological situations. This review summarizes recent advances in vascularized platforms, standard and microfluidic-based techniques for EV isolation and characterization, and studies of EVs in vascularized platforms. It provides insights into EV-related (patho)physiological regulations and facilitates the development of EV-based therapeutics.

Mitochondria-containing extracellular vesicles from mouse vs. human brain endothelial cells for ischemic stroke therapy

Ischemic stroke-induced mitochondrial dysfunction in the blood-brain barrier-forming brain endothelial cells (BECs) results in long-term neurological dysfunction post-stroke. We previously reported data from a pilot study where intravenous administration of human BEC (hBEC)-derived mitochondria-containing extracellular vesicles (EVs) showed a potential efficacy signal in a mouse middle cerebral artery occlusion (MCAo) model of stroke. We hypothesized that EVs harvested from donor species homologous to the recipient species (e.g., mouse) may improve therapeutic efficacy, and therefore, use of mouse BEC (mBEC)-derived EVs may improve post-stroke outcomes in MCAo mice. We investigated potential differences in the mitochondria transfer of EVs derived from the same species as the recipient cell (mBEC-EVs and recipient mBECs or hBECs-EVs and recipient hBECs) vs. cross-species EVs and recipient cells (mBEC-EVs and recipient hBECs or vice versa). Our results showed that while both hBEC- and mBEC-EVs transferred EV mitochondria, mBEC-EVs outperformed hBEC-EVs in increasing ATP levels and improved recipient mBEC mitochondrial function via increasing oxygen consumption rates. mBEC-EVs significantly reduced brain infarct volume and neurological deficit scores compared to vehicle-injected MCAo mice. The superior therapeutic efficacy of mBEC-EVs in MCAo mice support the continued use of mBEC-EVs to optimize the therapeutic potential of mitochondria-containing EVs in preclinical mouse models.

Engineering strategies for apoptotic bodies

Extracellular vesicles (EVs) are lipid bilayer vesicles containing proteins, lipids, nucleic acids, and metabolites secreted by cells under various physiological and pathological conditions that mediate intercellular communication. The main types of EVs include exosomes, microvesicles, and apoptotic bodies (ABs). ABs are vesicles released during the terminal stages of cellular apoptosis, enriched with diverse biological entities and characterized by distinct morphological features. As a result, ABs possess great potential in fields like disease diagnosis, immunotherapy, regenerative therapy, and drug delivery due to their specificity, targeting capacity, and biocompatibility. However, their therapeutic efficacy is notably heterogeneous, and an overdose can lead to side effects such as accumulation in the liver, spleen, lungs, and gastrointestinal system. Through bioengineering, the properties of ABs can be optimized to enhance drug-loading efficiency, targeting precision, and multifunctionality for clinical implementations. This review focuses on strategies such as transfection, sonication, electroporation, surface engineering, and integration with biomaterials to enable ABs to load cargoes and enhance targeting, providing insights into the engineering of ABs.

Normotensive placental extracellular vesicles provide long-term protection against hypertension and cardiovascular disease

BACKGROUND

Women with normotensive pregnancy are at a reduced risk of developing cardiovascular disease postpartum compared with those who experience hypertensive conditions during pregnancy. However, the underlying mechanisms remain poorly understood. During normotensive pregnancy, vast numbers of placental extracellular vesicles are released into the maternal circulation, which protect endothelial cells from activation and alter maternal vascular tone. We hypothesized that placental extracellular vesicles play a mechanistic role in lowering the risk of cardiovascular disease following normotensive pregnancy.

OBJECTIVE

This study aimed to investigate the long-term effects of placental extracellular vesicles derived from normotensive term placentae on the cardiovascular system and explore the mechanisms underlying their biological effects.

STUDY DESIGN

Spontaneously hypertensive rats were injected with placental extracellular vesicles from normotensive term pregnancies (2 mg/kg each time, n=8) or vehicle control (n=9) at 3 months of age. Blood pressure and cardiac function were regularly monitored from 3 months to 15 months of age. The response of mesenteric resistance arteries to vasoactive substances was investigated to evaluate vascular function. Cardiac remodeling, small artery remodeling, and renal function were investigated to comprehensively assess the impact of placental extracellular vesicles on cardiovascular and renal health.

RESULTS

Compared with vehicle-treated control animals, rats treated with normotensive placental extracellular vesicles exhibited a significantly lower increase in blood pressure and improved cardiac function. Furthermore, the vasodilator response to the endothelium-dependent agonist acetylcholine was significantly enhanced in the normotensive placental extracellular vesicle-treated spontaneously hypertensive rats compared with the control. Moreover, treatment with placental extracellular vesicles reduced wall thickening of small renal vessels and attenuated renal fibrosis.

CONCLUSION

Placental extracellular vesicles from normotensive term pregnancies have long-lasting protective effects reducing hypertension and mitigating cardiovascular damage in vivo.

A Perspective on the Characterization of Early Neural Progenitor Cell-Derived Extracellular Vesicles for Targeted Delivery to Neuroblastoma Cells

As an element of the cellular signaling systems, extracellular vesicles (EVs) exhibit many desirable traits for usage as targeted delivery vehicles. When administered, EVs cause little to no toxic or immune response, stay in circulation for longer periods compared to synthetic carriers, preferentially accumulate in tissues that are the same or similar to their cell-of-origin and can pass through the blood-brain barrier. Combined, these traits make neural EVs a particularly promising tool for delivering drugs to the brain. This study aims to combine tissue and EVs engineering to prepare neural differentiated cells derived EVs that exhibit neural properties, to develop an effective, tissue-homing drug and gene delivery platform for the brain. Early neural differentiated cell-derived EVs were produced with neural characteristics from neural differentiated human neonatal dermal fibroblasts. The EVs carried key neural proteins such as Nestin, Sox2 and Doublecortin. The cellular uptake of early neural differentiated cell-derived EVs was higher compared to non-neural EVs during in vitro uptake assays on neuroblastoma cells. Moreover, eND-EVs were significantly decreased the viability of neuroblastoma cells. In conclusion, this study revealed that early neural differentiated cell-derived EVs have potential as a promising drug carrier for the treatment of various neural disorders.

Playing pin-the-tail-on-the-protein in extracellular vesicle (EV) proteomics

Extracellular vesicles (EVs) are anucleate particles enclosed by a lipid bilayer that are released from cells via exocytosis or direct budding from the plasma membrane. They contain an array of important molecular cargo such as proteins, nucleic acids, and lipids, and can transfer these cargoes to recipient cells as a means of intercellular communication. One of the overarching paradigms in the field of EV research is that EV cargo should reflect the biological state of the cell of origin. The true relationship or extent of this correlation is confounded by many factors, including the numerous ways one can isolate or enrich EVs, overlap in the biophysical properties of different classes of EVs, and analytical limitations. This presents a challenge to research aimed at detecting low-abundant EV-encapsulated nucleic acids or proteins in biofluids for biomarker research and underpins technical obstacles in the confident assessment of the proteomic landscape of EVs that may be affected by sample-type specific or disease-associated proteoforms. Improving our understanding of EV biogenesis, cargo loading, and developments in top-down proteomics may guide us towards advanced approaches for selective EV and molecular cargo enrichment, which could aid EV diagnostics and therapeutics research.

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

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

Plant-Derived Extracellular Vesicles as a Novel Frontier in Cancer Therapeutics

Recent advancements in nanomedicine and biotechnology have unveiled the remarkable potential of plant-derived extracellular vesicles (PDEVs) as a novel and promising approach for cancer treatment. These naturally occurring nanoscale particles exhibit exceptional biocompatibility, targeted delivery capabilities, and the capacity to load therapeutic agents, positioning them at the forefront of innovative cancer therapy strategies. PDEVs are distinguished by their unique properties that facilitate tumor targeting and penetration, thereby enhancing the efficacy of drug delivery systems. Their intrinsic biological composition allows for the evasion of the immune response, enabling the efficient transport of loaded therapeutic molecules directly to tumor sites. Moreover, PDEVs possess inherent anti-cancer properties, including the ability to induce cell cycle arrest and promote apoptotic pathways within tumor cells. These vesicles have also demonstrated antimetastatic effects, inhibiting the spread and growth of cancer cells. The multifunctional nature of PDEVs allows for the simultaneous delivery of multiple therapeutic agents, further enhancing their therapeutic potential. Engineering and modification techniques, such as encapsulation, and the loading of therapeutic agents via electroporation, sonication, and incubation, have enabled the customization of PDEVs to improve their targeting efficiency and therapeutic load capacity. This includes surface modifications to increase affinity for specific tumor markers and the encapsulation of various types of therapeutic agents, such as small molecule drugs, nucleic acids, and proteins. Their plant-derived origin offers an abundant and renewable source to produce therapeutic vesicles, reducing costs and facilitating scalability for clinical applications. This review provides an in-depth analysis of the latest research on PDEVs as emerging anti-cancer agents in cancer therapy.

Therapeutic potential of adipose-derived stem cell extracellular vesicles: from inflammation regulation to tissue repair

Inflammation is a key pathological feature of many diseases, disrupting normal tissue structure and resulting in irreversible damage. Despite the need for effective inflammation control, current treatments, including stem cell therapies, remain insufficient. Recently, extracellular vesicles secreted by adipose-derived stem cells (ADSC-EVs) have garnered attention for their significant anti-inflammatory properties. As carriers of bioactive substances, these vesicles have demonstrated potent capabilities in modulating inflammation and promoting tissue repair in conditions such as rheumatoid arthritis, osteoarthritis, diabetes, cardiovascular diseases, stroke, and wound healing. Consequently, ADSC-EVs are emerging as promising alternatives to conventional ADSC-based therapies, offering advantages such as reduced risk of immune rejection, enhanced stability, and ease of storage and handling. However, the specific mechanisms by which ADSC-EVs regulate inflammation under pathological conditions are not fully understood. This review discusses the role of ADSC-EVs in inflammation control, their impact on disease prognosis, and their potential to promote tissue repair. Additionally, it provides insights into future clinical research focused on ADSC-EV therapies for inflammatory diseases, which overcome some limitations associated with cell-based therapies.

Biomimetic strategies for the deputization of proteoglycan functions

Proteoglycans (PGs), which have glycosaminoglycan chains attached to their protein cores, are essential for maintaining the morphology and function of healthy body tissues. Extracellular PGs perform various functions, classified into the following four categories: i) the modulation of tissue mechanical properties; ii) the regulation and protection of the extracellular matrix; iii) protein sequestration; and iv) the regulation of cell signaling. The depletion of PGs may significantly impair tissue function, encompassing compromised mechanical characteristics and unregulated inflammatory responses. Since PGs play critical roles in the function of healthy tissues and their synthesis is complex, the development of PG mimetic molecules that recapitulate PG functions for tissue engineering and therapeutic applications has attracted the interest of researchers for more than 20 years. These approaches have ranged from semisynthetic graft copolymers to recombinant PG domains produced by cells that have undergone genetic modifications. This review discusses some essential extracellular PG functions and approaches to mimicking these functions.

Momordica charantia L.-derived exosome-like nanovesicles stabilize p62 expression to ameliorate doxorubicin cardiotoxicity

BACKGROUND

Doxorubicin (DOX) is a first-line chemotherapeutic drug for various malignancies that causes cardiotoxicity. Plant-derived exosome-like nanovesicles (P-ELNs) are growing as novel therapeutic agents. Here, we investigated the protective effects in DOX cardiotoxicity of ELNs from Momordica charantia L. (MC-ELNs), a medicinal plant with antioxidant activity.

RESULTS

We isolated MC-ELNs using ultracentrifugation and characterized them with canonical mammalian extracellular vesicles features. In vivo studies proved that MC-ELNs ameliorated DOX cardiotoxicity with enhanced cardiac function and myocardial structure. In vitro assays revealed that MC-ELNs promoted cell survival, diminished reactive oxygen species, and protected mitochondrial integrity in DOX-treated H9c2 cells. We found that DOX treatment decreased the protein level of p62 through ubiquitin-dependent degradation pathway in H9c2 and NRVM cells. However, MC-ELNs suppressed DOX-induced p62 ubiquitination degradation, and the recovered p62 bound with Keap1 promoting Nrf2 nuclear translocation and the expressions of downstream gene HO-1. Furthermore, both the knockdown of Nrf2 and the inhibition of p62-Keap1 interaction abrogated the cardioprotective effect of MC-ELNs.

CONCLUSIONS

Our findings demonstrated the therapeutic beneficials of MC-ELNs via increasing p62 protein stability, shedding light on preventive approaches for DOX cardiotoxicity.

Evolving Role of Exosomes in Plastic and Reconstructive Surgery and Dermatology

Exosomes, or extracellular vesicles, represent the latest cell-free addition to the regenerative medicine toolkit. In vitro preclinical studies have demonstrated the safety and efficacy of exosomes, which vary based on source and biomanufacturing, for a myriad of potential therapeutic applications relevant to skin and soft tissue reconstruction. Primary search was performed in September 2021 on the MEDLINE database via PubMed and Ovid, with focus on articles about therapeutic application of exosomes or extracellular vesicles. In total, 130 articles met criteria for applicability, including early-stage clinical trials, preclinical research studies with in vivo application, and articles applicable to plastic and reconstructive surgery and dermatology. Most studies used animal models of human disease processes, using either animal donor cells to isolate exosomes, or human donor cells in animal models. Exosome technology has catapulted as an acellular therapeutic vehicle with off-the-shelf accessibility. These features eliminate prior threshold for broad adoption of regenerative cell-based therapies into surgical and medical practice. To date, there are no exosome products approved by the US Food and Drug Administration. This review highlights exosomes as the new frontier in regenerative medicine and outlines its preclinical therapeutic applications for cutaneous repair and restoration.

Exploring the potential of cell-derived vesicles for transient delivery of gene editing payloads

Gene editing technologies have the potential to correct genetic disorders by modifying, inserting, or deleting specific DNA sequences or genes, paving the way for a new class of genetic therapies. While gene editing tools continue to be improved to increase their precision and efficiency, the limited efficacy of in vivo delivery remains a major hurdle for clinical use. An ideal delivery vehicle should be able to target a sufficient number of diseased cells in a transient time window to maximize on-target editing and mitigate off-target events and immunogenicity. Here, we review major advances in novel delivery platforms based on cell-derived vesicles - extracellular vesicles and virus-like particles - for transient delivery of gene editing payloads. We discuss major findings regarding packaging, in vivo biodistribution, therapeutic efficacy, and safety concerns of cell-derived vesicles delivery of gene editing cargos and their potential for clinical translation.

Improving Granulosa Cell Function in Premature Ovarian Failure with Umbilical Cord Mesenchymal Stromal Cell Exosome-Derived hsa_circ_0002021

BACKGROUND

The therapeutic potential of exosomes from human umbilical cord mesenchymal stem cells (HUMSCs-Exo) for delivering specific circular RNAs (circRNAs) in treating premature ovarian failure (POF) is not well understood. This study aimed to explore the efficacy of HUMSCs-Exo in delivering hsa_circ_0002021 for POF treatment, focusing on its effects on granulosa cell (GC) senescence and ovarian function.

METHODS

Bioinformatic analysis was conducted on circRNA profiles using the GSE97193 dataset from GEO, targeting granulosa cells from varied age groups. To simulate granulosa cell senescence, KGN cells were treated with cyclophosphamide (CTX). HUMSCs were transfected with pcDNA 3.1 vectors to overexpress hsa_circ_0002021, and the HUMSCs-Exo secreted were isolated. These exosomes were characterized by transmission electron microscopy (TEM) and Western blotting to confirm exosomal markers CD9 and CD63. Co-culture of these exosomes with CTX-treated KGN cells was performed to assess β-galactosidase activity, oxidative stress markers, ROS levels, and apoptosis via flow cytometry. Interaction between hsa_circ_0002021, microRNA-125a-5p (miR-125a-5p), and cyclin-dependent kinase 6 (CDK6) was investigated using dual-luciferase assays and RNA immunoprecipitation (RIP). A POF mouse model was induced with CTX, treated with HUMSCs-Exo, and analyzed histologically and via immunofluorescence staining. Gene expression was quantified using RT-qPCR and Western blot.

RESULTS

hsa_circ_0002021 was under expressed in both in vivo and in vitro POF models and was effectively delivered by HUMSCs-Exo to KGN cells, showing a capability to reduce GC senescence. Overexpression of hsa_circ_0002021 in HUMSCs-Exo significantly enhanced these anti-senescence effects. This circRNA acts as a competitive adsorbent of miR-125a-5p, regulating CDK6 expression, which is crucial in modulating cell cycle and apoptosis. Enhanced expression of hsa_circ_0002021 in HUMSCs-Exo ameliorated GC senescence in vitro and improved ovarian function in POF models by modulating oxidative stress and cellular senescence markers.

CONCLUSION

This study confirms that hsa_circ_0002021, when delivered through HUMSCs-Exo, can significantly mitigate GC senescence and restore ovarian function in POF models. These findings provide new insights into the molecular mechanisms of POF and highlight the therapeutic potential of circRNA-enriched exosomes in treating ovarian aging and dysfunction.

Exploring the Therapeutic Potential of Extracellular Vesicles Derived from Human Immature Dental Pulp Cells on Papillary Thyroid Cancer

Mesenchymal stem-cell-derived extracellular vesicles (MSC-EVs) have been increasingly investigated for cancer therapy and drug delivery, and they offer an advanced cell-free therapeutic option. However, their overall effects and efficacy depend on various factors, including the MSC source and cargo content. In this study, we isolated EVs from the conditioned medium of human immature dental pulp stem cells (hIDPSC-EVs) and investigated their effects on two papillary thyroid cancer (PTC) cell lines (BCPAP and TPC1). We observed efficient uptake of hIDPSC-EVs by both PTC cell lines, with a notable impact on gene regulation, particularly in the Wnt signaling pathway in BCPAP cells. However, no significant effects on cell proliferation were observed. Conversely, hIDPSC-EVs significantly reduced the invasive capacity of both PTC cell lines after 120 h of treatment. These in vitro findings suggest the therapeutic potential of hIDPSC-EVs in cancer management and emphasize the need for further research to develop novel and effective treatment strategies. Furthermore, the successful internalization of hIDPSC-EVs by PTC cell lines underscores their potential use as nanocarriers for anti-cancer agents.