Trehalose prevents aggregation of exosomes and cryodamage

Elucidation of extracellular vesicles behavior during capillary isoelectric focusing

In this study, we investigated the behavior of extracellular vesicles (EVs), during capillary isoelectric focusing (cIEF). For that, we used different approaches, imaging cIEF with a whole-column imaging detection (WCID) and conventional cIEF as well as different detection methods (LIF after EV labelling, native fluorescence and UV). Our study reveals that EVs exhibit significant aggregation during their migration toward, and upon reaching, their isoelectric point (pI). By optimizing key parameters such as voltage and the addition of solubilizers, we successfully reduced this issue, particularly with bovine milk EVs. Our findings also showed distinct pI regions observed for EVs isolated from different sources: bovine milk EVs shows acidic pI characteristics (4.0-4.1), while pig and human plasma EVs exhibit more basic pI zones (4.7-4.9 and 5.8-6.7, respectively). The study was extended to cIEF coupled to laser induced fluorescence detection (LIF) using intra-vesicular CFDA-labeled EVs, to better understand their susceptibilities. Prolonged mobilization time due to long capillary lengths adversely affected EV's integrity in conventional cIEF. Our study reveals the necessity to specific cIEF optimization for each EV source due to variations in charge distribution and aggregation behavior across different pI regions. The use of a short capillary length (<10 cm), low electric field and solubilizers such as Tween-20 is recommended to preserve EVs integrity during cIEF-EV studies.

Tetraspanin 4 Mediates Cholesterol-Dependent Exosome Membrane Protection from Cryodamage

Exosomes, nanosized extracellular vesicles carrying proteins, lipids, and nucleic acids, hold great potential in therapeutic applications. Cryopreservation, a widely used method for their preservation and transport, often causes irreversible damage. Understanding the molecular mechanisms underlying biomembrane resistance to cryodamage is crucial for advancing cryopreservation techniques. In this study, we find that tetraspanin 4 (TSPAN4) and other tetraspanin family proteins play an essential role in protecting exosomes from cryodamage, likely due to their role in cholesterol binding and membrane microdomain formation. Furthermore, we engineered TSPAN4-loaded exosomes, which demonstrated enhanced cryoprotection while maintaining a similar protein composition and uptake efficiency compared to wild-type exosomes. Our novel cryopreservation strategy, which does not rely on external agents, offers a promising approach for advancing the clinical translation of exosomes as therapeutic agents.

Encapsulation of Small Extracellular Vesicles into Selectively Disassemblable Shells of PEGylated Metal-Phenolic Networks

Small extracellular vesicles (sEVs) are cell-derived particles used for intercellular communication in living organisms that have gained great interest from researchers for their use as drug carriers and diagnostic agents. However, the isolation and storage of sEVs lead to issues including lipid membrane disruption, protein denaturation, and nucleic acid degradation. Herein, a surface functionalization strategy is reported for encapsulating single sEV into selectively disassemblable protective shells composed of metal-phenolic networks (MPNs) post-modified with poly(ethylene glycol) (PEG). Disassemblable MPN shells can be rapidly deposited on sEVs in a one-step manner and post-modified with PEG. These coatings enhance the colloidal stability of sEVs and protect them against harsh storage conditions, while the non-covalent and selectively disassemblable nature of the MPN shell allows recovery after storage without compromising their surface integrity and functionality. It is demonstrated that various triggers, such as pH adjustment, competitive chelation, and redox reactions, can be used to disassemble the MPN shell, thereby offering widely adoptable strategies depending on the target applications. This approach potentially overcomes conventional challenges associated with sEV processing and storage and may contribute to reducing cold-chain requirements and transportation costs of future sEVs-based therapeutics and diagnostics.

A Biomimetic Mineralization Strategy for the Long-Term Preservation of Exosomes Through Non-Destructive Encapsulation Within Zeolite Imidazolate Frameworks-8

Exosomes, which are extracellular vesicles derived from endosomes, play a crucial role in mediating intercellular communication and are widely used in medical diagnostics and drug delivery. Conventional cryopreservation strategies can damage the integrity of exosomes, hindering their further application in the biomedical field. Here, a novel approach is developed for exosome storage, shell of intact exosomes holding (SHIELD), which packages exosomes in zeolite imidazolate frameworks-8 (ZIF-8) as a protective shell. ZIF-8 shell can be quickly removed, and meanwhile, the inherent morphology and biological function of exosomes can be preserved, thereby mitigating potential biocompatible risks associated with ZIF-8. Notably, the SHIELD-protected exosomes maintained their intact morphology and cellular uptake capacity, and 76% of the original protein content can be kept even after being stored for one month. Overall, the development of SHIELD overcomes the challenges of traditional techniques of exosome preservation and further broadens the biomedical applications of ZIF-8 and exosomes.

Defining Biological Variability, Analytical Precision and Quantitative Biophysiochemical Characterization of Human Urinary Extracellular Vesicles

The magnitude of combined analytical errors of urinary extracellular vesicle (uEV) preparation and measurement techniques (CVA) has not been thoroughly investigated to determine whether it exceeds biological variations. We utilized technical replicates of human urine to assess the repeatability of uEV concentration and size measurements by nanoparticle tracking analysis (NTA) following differential velocity centrifugation (DC), silicon carbide, or polyethylene glycol uEV isolation methods. The DC method attained the highest precision. Consequently, DC-derived uEV size, most abundant protein levels, and optical redox ratio (ORR) were further assessed by dynamic light scattering (DLS), immunoblotting or multi-photon (SLAM) microscopy. Procedural errors primarily affected uEV counting and uEV-associated protein quantification, while instrumental errors contributed most to the total variability of NTA- and DLS-mediated uEV sizing processes. The intra-individual variability (CVI) of uEV counts assessed by NTA was smaller than inter-individual variability (CVG), resulting in an estimated index of individuality IOI < 0.6, suggesting that personalized reference interval (RI) is more suitable for interpretation of changes in subject's test results. Population-based RI was more appropriate for ORR (IOI > 1.4). The analytical performance of DC-NTA and DC-SLAM techniques met optimal CVA < 0.5 × CVI criteria, indicating their suitability for further testing in clinical laboratory settings.

Revisiting the Nanoflow Cytometric Quantification of Extracellular Vesicles Under the Framework of ICH Q14 Guidelines

Nanoflow cytometry (nanoFCM) is an increasingly important analytical procedure in every aspect of extracellular vesicle (EV) research, particularly in the development of EV-based therapeutics. The main objective of this study was to evaluate and optimise the key determinant factors of nanoFCM in the quantification analysis of EVs to ensure its consistency and reliability in the development of EV therapeutic drugs, thereby serving as a potential quality control measure. Our investigation followed the International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use (ICH) Q14 guideline. We revisited the day-to-day practice of nanoFCM measurement for HEK293 cell-derived and milk-derived EVs (mEVs), focusing on optimising particle quantification and identifying risk factors. Initial evaluation of the procedure revealed a considerable lack of consistency and reliability, which was then subjected to extensive optimisation. The key outcomes of this study include: (1) an optimised analytic procedure incorporating Tween-20, which significantly enhanced the precision and accuracy of the nanoFCM measurement and expanded the reportable range; (2) an analytical target profile (ATP) which provides a preliminary standard for future validation of nanoFCM procedures. Overall, this study serves as a foundation for future efforts towards the standardisation of analytical procedures for EV therapeutics.

The existing evidence for the use of extracellular vesicles in the treatment of osteoporosis: a review

Osteoporosis is a systemic metabolic bone disease characterized by decreased bone mass, microstructural deterioration, and increased fracture risk. The crucial role of extracellular vesicles (EVs) in the occurrence and development of osteoporosis has garnered attention, with vesicle-based treatments showing significant promise. Compared to conventional osteoporosis medications, EVs possess characteristics of naturalness, selectivity, and adaptability, and more importantly, they have negligible side effects. Hence, this review discusses the applications of natural and engineered EVs in osteoporosis are comprehensively outlined. Unfortunately, the absence of consensus on the extraction, purification, characterization, and storage of EVs has resulted in a lack of clinical evidence supporting their application in patients with osteoporosis. Although significant progress is still needed before the clinical use of EVs can be achieved, their substantial potential remains undeniable. Moreover, considering the complexity of bone metabolism in osteoporosis and the heterogeneity of EVs, further investigation into the functional subpopulations of different exosomes will facilitate their application.

The Roles of Exosomes in Anti-Cancer Drugs

BACKGROUND

Cancer is an escalating global health issue, with rising incidence rates annually. Chemotherapy, a primary cancer treatment, often exhibits low tumor-targeting efficiency and severe side effects, limiting its effectiveness. Recent research indicates that exosomes, due to their immunogenicity and molecular delivery capabilities, hold significant potential as drug carriers for tumor treatment.

METHODS

This review summarizes the current status, powerful therapeutic potential, and challenges of using exosomes for the treatment of tumors.

RESULTS

Exosomes are crucial in tumor diagnosis, onset, and progression. To improve the efficacy of exosome-based treatments, researchers are exploring various biological, physical, and chemical approaches to engineer exosomes as a new nanomedicine translational therapy platform with broad and alterable therapeutic capabilities. Numerous clinical trials are currently underway investigating the safety and tolerability of exosomes carrying drugs to specific sites for the treatment of tumors.

CONCLUSIONS

Exosomes can be engineered as carriers to deliver therapeutic molecules to specific cells and tissues, offering a novel approach for disease treatment.

Scalability of spheroid-derived small extracellular vesicles production in stirred systems

Introduction

Small extracellular vesicle (sEV)-based therapies have gained widespread interest, but challenges persist to ensure standardization and high-scale production. Implementing upstream processes in a chemically defined media in stirred-tank bioreactors (STBr) is mandatory to closely control the cell environment, and to scale-up production, but it remains a significant challenge for anchorage-dependent cells.

Methods

We used a human β cell line, grown as monolayer or in suspension as spheroid in stirred systems. We assessed the consequences of culturing these cells in 3D with, or without fetal bovine serum in a chemically defined medium, for cell growth, viability and metabolism. We next explored how different scale-up strategies might influence cell and spheroid formation in spinner flask, with the aim to transfer the process in instrumented Ambr®250 STBr. Lastly, we analyzed and characterized sEV production in monolayer, spinner flask and STBr.

Results and discussion

Generation of spheroids in a chemically defined medium allowed the culture of highly viable cells in suspension in stirred systems. Spheroid size depended on the system's volumetric power input (P/V), and maintaining this parameter constant during scale-up proved to be the optimal strategy for standardizing the process. However, transferring the spinner flask (SpF) process to the Ambr®250 STBr at constant P/V modified spheroid size, due to important geometric differences and impeller design. Compared to a monolayer reference process, sEV yield decreased two-fold in SpF, but increased two-fold in STBr. Additionally, a lower expression of the CD63 tetraspanin was observed in sEV produced in both stirred systems, suggesting a reduced release of exosomes compared to ectosomes. This study addresses the main issues encountered in spheroid culture scale-up in stirred systems, rather conducive for the production of ectosomes.

Biomanufacturing and Curcumin-Loading of Human Choroid Plexus Organoid-Derived Extracellular Vesicles from a Vertical-Wheel Bioreactor to Alleviate Neuro-Inflammation

Background: Choroid plexus is a complex structure in the human brain that is responsible for the secretion of extracellular vesicles (EVs) in cerebrospinal fluid. Few studies to date have generated choroid plexus (ChP) organoids differentiated from human induced pluripotent stem cells (hiPSCs) and analyzed their secreted EVs. The scalable Vertical-Wheel bioreactors (VWBRs) provide low shear stress and a controlled environment. Methods: This study utilized VWBRs for the differentiation of hiPSCs into ChP organoids and generation of the secreted EVs compared to a static culture. Additionally, this study loaded curcumin into ChP organoid-derived EVs, performed EV lyophilization, and determined the ability of the re-hydrated EVs to alleviate neuro-inflammation. Results: The results demonstrated that the VWBR culture exhibited more aerobic metabolism and active glucose and glutamine consumption than the static control. Consequently, the ChP markers and Endosomal Sorting Complexes Required for Transport-dependent and -independent EV biogenesis genes were significantly upregulated (2-3-fold) in the VWBR, producing four-fold-higher EVs per mL media than the static control. The EVs retained similar size and zeta potential after lyophilization and re-hydration. The cells exposed to amyloid beta 42 oligomers and treated with the curcumin-loaded re-hydrated EVs showed high viability and the reduced inflammatory response determined by TNF-α and IL-6 expression. Conclusions: This study demonstrates a scalable bioreactor system to promote ChP organoid differentiation and generation of EV-based cell-free therapeutics to treat neural inflammation in various neurological disorders.

Streptococcus mutans-derived extracellular vesicles promote skin wound healing via tRNA cargo

BACKGROUND

The human oral cavity harbors a diverse microbiota, including Streptococcus species. Oral mucosal wounds heal rapidly, although the exact cause remains unclear. This study investigates the impact of Streptococcus mutans-derived extracellular vesicles (Sm EVs) on wound healing in both oral mucosal organoids and mouse skin. To explore whether microbial EV RNA cargo influences wound healing, RNA sequences from Sm EVs were identified, and the most abundant sequences were synthesized into oligomers and encapsulated in E. coli EVs (Ec EVs) for further in vivo testing. We assessed the role of Toll-like receptor 3 (TLR3) in the wound healing mechanism in TLR3 knockout (KO) mice.

RESULTS

Sm EVs significantly enhanced cell proliferation and migration in oral mucosa, with enhanced focal adhesion complex formation. Sm EVs improved wound healing in mouse dorsal skin compared to PBS controls. RNA sequencing revealed that bacterial tRNAs, particularly the tRNA-Met variant (Oligo 1), were the most abundant RNAs in Sm EVs. Ec EVs carrying Oligo 1 produced similar wound healing effects to Sm EVs in mucosal organoids and mouse dorsal skin. However, in TLR3 knockout mice, Oligo 1 did not improve wound healing.

CONCLUSIONS

This study highlights the role of Sm EVs, particularly their tRNA variants, in promoting skin wound healing through a TLR3-dependent mechanism. These findings suggest that EVs from oral commensal bacteria may offer therapeutic potential for chronic, non-healing skin wounds.

Cutting-Edge Progress in the Acquisition, Modification and Therapeutic Applications of Exosomes for Drug Delivery

Exosomes are vesicles secreted by cells, typically ranging from 30 to 150 nm in diameter, and serve as crucial mediators of intercellular communication. Exosomes are capable of loading various therapeutic substances, such as small molecule compounds, proteins, and oligonucleotides, thereby making them an ideal vehicle for drug delivery. The distinctive biocompatibility, high stability, and targeting properties of exosomes render them highly valuable for future treatments of diseases like cancer and cardiovascular diseases. Despite the potential advantage of exosomes in delivering biologically active molecules, the techniques for the preparation, purification, preservation, and other aspects of stem cell exosomes are not yet mature enough. In this paper, we briefly introduce the composition, biogenesis, and benefits of exosomes, and primarily focus on summarizing the isolation and purification methods of exosomes, the preparation of engineered exosomes, and their clinical applications, to better provide new ideas for the development of exosome drug delivery systems.

Stability Dynamics of Plant-Based Extracellular Vesicles Drug Delivery

Plant-based extracellular vesicles (PBEVs) have been recognized for their wide range of applications in drug delivery however, the extent of their medicinal applicability depends on how well they are preserved and stored. Assessing their physicochemical properties, such as size, particle concentration, shape, and the activity of their cargo, forms the foundation for determining their stability during storage. Moreover, the evaluation of PBEVs is essential to ensure both safety and efficacy, which are critical for advancing their clinical development. Maintaining the biological activity of EVs during storage is a challenging task, similar to the preservation of cells and other cell-derived products like proteins. However, despite limited studies, it is expected that storing drug-loaded EVs may present fewer challenges compared to cell-based therapies, although some limitations are inevitable. This article provides a comprehensive overview of current knowledge on PBEVs preservation and storage methods, particularly focusing on their role as drug carriers. PBEVs hold promise as potential candidates for oral drug administration due to their effective intestinal absorption and ability to withstand both basic and acidic environments. However, maintaining their preservation and stability during storage is critical. Moreover, this review centers on the isolation, characterization, and storage of PBEVs, exploring the potential advantages they offer. Furthermore, it highlights key areas that require further research to overcome existing challenges and enhance the development of effective preservation and storage methods for therapeutic EVs.

Lactobacillus-derived artificial extracellular vesicles for skin rejuvenation and prevention of photo-aging

Extracellular vesicles (EVs) are small membrane-bound sacs released by cells that play crucial roles in intercellular communication. They transport biomolecules between cells and have both diagnostic and therapeutic potential. Artificial EVs, designed to mimic natural EVs, have been developed using various methods. In this study, Lactobacillus plantarum was used to create Lactobacillus-derived artificial EVs (LAEs) for skin rejuvenation and anti-aging. LAEs demonstrated monodispersity and effectively improved adverse gene expression and wound healing in fibroblasts. They also modulated aging-related genes and improved skin conditions in humans. Their simplicity, promptness, and lack of animal-derived sources make LAEs a promising alternative to natural EVs. LAEs have the potential to overcome the technical limitations of artificial EVs and advance EVs or exosome-based technologies for comprehensive skin rejuvenation.

Exosomes: from basic research to clinical diagnostic and therapeutic applications in cancer

Cancer continues to pose a global threat despite potent anticancer drugs, often accompanied by undesired side effects. To enhance patient outcomes, sophisticated multifunctional approaches are imperative. Small extracellular vesicles (EVs), a diverse family of naturally occurring vesicles derived from cells, offer advantages over synthetic carriers. Among the EVs, the exosomes are facilitating intercellular communication with minimal toxicity, high biocompatibility, and low immunogenicity. Their tissue-specific targeting ability, mediated by surface molecules, enables precise transport of biomolecules to cancer cells. Here, we explore the potential of exosomes as innovative therapeutic agents, including cancer vaccines, and their clinical relevance as biomarkers for clinical diagnosis. We highlight the cargo possibilities, including nucleic acids and drugs, which make them a good delivery system for targeted cancer treatment and contrast agents for disease monitoring. Other general aspects, sources, and the methodology associated with therapeutic cancer applications are also reviewed. Additionally, the challenges associated with translating exosome-based therapies into clinical practice are discussed, together with the future prospects for this innovative approach.

Unravelling exosome paradigm: Therapeutic, diagnostic and theranostics application and regulatory consideration

In the recent decade, extracellular vesicles (EVs) have been released from nearly all the kingdoms, modulating intercellular communication and maintaining the human body's homeostasis by regulating different cellular processes. Among EVs, exosomes are the emerging field in biopharmaceuticals. They have lipid bilayer ranging from 30 to 150 nm in size and encompass DNA, RNA, protein lipids, etc. Their sources are widespread, easy to acquire, and cost-effective in manufacturing. This review focuses on the detailed classification of exosomes existing in nature, knowledge and application of omics, therapeutic, diagnostic and theranostic application of exosomes. It covers diseases such as cancer, infectious diseases (viral, bacterial, fungal infections), neurodegenerative diseases, metabolic diseases, lifestyle diseases (diabetes, cardiovascular, gastric disorder (IBD)), autoimmune disorders and their biodistribution. This article unfolds the recent progress in the exosomes arena and covers all the regulatory considerations (FDA, EMA, and other nations) involved with it. Moreover, a detailed discussion about clinical trials and its manifestation with exosomes and challenges associated with their isolation procedures, reproducibility, and safety concerns.

Magnetically Labeled iPSC-Derived Extracellular Vesicles Enable MRI/MPI-Guided Regenerative Therapy for Myocardial Infarction

Stem cell-derived extracellular vesicles (EVs) offer a promising cell-free approach for cardiovascular regenerative medicine. In this study, we developed magnetically labeled induced pluripotent stem cell-derived EVs (magneto-iPSC-EVs) encapsulated with superparamagnetic iron oxide (SPIO) nanoparticles for image-guided regenerative treatment of myocardial infarction, in which EVs that can be detected by both magnetic resonance imaging (MRI) and magnetic particle imaging (MPI). iPSC-EVs were isolated, characterized per MISEV2023 guidelines, and loaded with SuperSPIO20 nanoparticles using optimized electroporation conditions (300 V, 2 × 10 ms pulses), achieving a high loading efficiency of 1.77 ng Fe/106 EVs. In vitro results show that magneto-iPSC-EVs can be sensitively detected by MPI and MRI, with a detectability of approximately 107 EVs. In a mouse myocardial ischemia-reperfusion model, intramyocardially injected magneto-iPSC-EVs (2 × 109) were imaged non-invasively by in vivo MPI for 7 days and ex vivo MRI, with the presence of magneto-iPSC-EVs confirmed by Prussian blue staining. Therapeutically, both native and magneto- iPSC-EVs significantly improved cardiac function, with a 37.3% increase in left ventricular ejection fraction and 61.0% reduction in scar size. This study highlights the potential of magneto-iPSC-EVs as a cell-free approach for cardiovascular regenerative medicine, offering both non-invasive imaging capabilities and therapeutic benefits for myocardial repair.

Mesenchymal stem cell-derived exosomes as a plausible immunomodulatory therapeutic tool for inflammatory diseases

Mesenchymal stem cell-derived extracellular vesicles (MSC-EVs), especially, exosomes are considered to have diverse therapeutic effects for various significant diseases. MSC-derived exosomes (MSCex) offer substantial advantages over MSCs due to their long-term preservation, stability, absence of nuclei and fewer adverse effects such as infusion toxicity, thereby paving the way towards regenerative medicine and cell-free therapeutics. These exosomes harbor several cellular contents such as DNA, RNA, lipids, metabolites, and proteins, facilitating drug delivery and intercellular communication. MSCex have the ability to immunomodulate and trigger the anti-inflammatory process hence, playing a key role in alleviating inflammation and enhancing tissue regeneration. In this review, we addressed the anti-inflammatory effects of MSCex and the underlying immunomodulatory pathways. Moreover, we discussed the recent updates on MSCex in treating specific inflammatory diseases, including arthritis, inflammatory bowel disease, inflammatory eye diseases, and respiratory diseases such as asthma and acute respiratory distress syndrome (ARDS), as well as neurodegenerative and cardiac diseases. Finally, we highlighted the challenges in using MSCex as the successful therapeutic tool and discussed future perspectives.

Prospect of extracellular vesicles in tumor immunotherapy

Extracellular vesicles (EVs), as cell-derived small vesicles, facilitate intercellular communication within the tumor microenvironment (TME) by transporting biomolecules. EVs from different sources have varied contents, demonstrating differentiated functions that can either promote or inhibit cancer progression. Thus, regulating the formation, secretion, and intake of EVs becomes a new strategy for cancer intervention. Advancements in EV isolation techniques have spurred interest in EV-based therapies, particularly for tumor immunotherapy. This review explores the multifaceted functions of EVs from various sources in tumor immunotherapy, highlighting their potential in cancer vaccines and adoptive cell therapy. Furthermore, we explore the potential of EVs as nanoparticle delivery systems in tumor immunotherapy. Finally, we discuss the current state of EVs in clinical settings and future directions, aiming to provide crucial information to advance the development and clinical application of EVs for cancer treatment.

Scalable production of anti-inflammatory exosomes from three-dimensional cultures of canine adipose-derived mesenchymal stem cells: production, stability, bioactivity, and safety assessment

BACKGROUND

The therapeutic potential of exosomes derived from mesenchymal stem cells (MSCs) is increasingly recognized in veterinary medicine. This study explored the feasibility of a microcarrier-based three-dimensional (3D) culture system for producing the exosomes (cEXO). Investigations were conducted to enhance production efficiency, ensure stability, and evaluate the therapeutic potential of cEXO for anti-inflammatory applications while assessing their safety profile.

RESULTS

The microcarrier-based 3D culture system improved efficient production of cEXO, yielding exosomes with acceptable profiles, including a size of approximately 81.22 nm, negative surface charge, and high particle concentration (1.32 × 109 particles/mL). Confocal imaging proved dynamic changes in cell viability across culture phases, highlighting the challenges of maintaining cell viability during repeated exosome collection cycles. Characterization via transmission electron microscopy, nanoparticle tracking analysis, and zeta-potential measurements confirmed the stability and functionality of cEXO, particularly when stored at -20 °C. Functional assays showed that cEXO exerted significant anti-inflammatory activity in RAW264.7 macrophages in an inverse dose-dependent manner, with no observed cytotoxicity to fibroblasts or macrophages. Acute toxicity testing in rats revealed no adverse effects on clinical parameters, organ health, or body weight, supporting the safety of cEXO for therapeutic use.

CONCLUSIONS

This study highlights the potential of a microcarrier-based 3D culture system for scalable cEXO production with robust anti-inflammatory activity, stability, and safety profiles. These findings advance the development of cEXO-based therapies and support their application in veterinary regenerative medicine.

Extracellular vesicles: from intracellular trafficking molecules to fully fortified delivery vehicles for cancer therapeutics

Extracellular vesicles (EVs) are emerging as viable tools in cancer treatment due to their ability to carry a wide range of theranostic activities. This review summarizes different forms of EVs such as exosomes, microvesicles, apoptotic bodies, and oncosomes. It also sheds the light onto isolation methodologies, characterization techniques and therapeutic applications of all discussed EVs. Evidence indicates that EVs are particularly effective in delivering chemotherapeutic medications, and immunomodulatory agents. However, the advancement of EV-based therapies into clinical practice is hindered by challenges including EVs heterogeneity, cargo loading efficiency, and in vivo stability. Overall, EVs have the potential to change cancer therapeutic paradigms. Continued research and development activities are critical for improving EV-based medications and increasing their therapeutic impact.

miRNA in blood-brain barrier repair: role of extracellular vesicles in stroke recovery

Ischemic stroke is a leading cause of mortality and long-term disability globally. One of its aspects is the breakdown of the blood-brain barrier (BBB). The disruption of BBB's integrity during stroke exacerbates neurological damage and hampers therapeutic intervention. Recent advances in regenerative medicine suggest that mesenchymal stem cells (MSCs) derived extracellular vesicles (EVs) show promise for restoring BBB integrity. This review explores the potential of MSC-derived EVs in mediating neuroprotective and reparative effects on the BBB after ischemic stroke. We highlight the molecular cargo of MSC-derived EVs, including miRNAs, and their role in enhancing angiogenesis, promoting the BBB and neural repair, and mitigating apoptosis. Furthermore, we discuss the challenges associated with the clinical translation of MSC-derived EV therapies and the possibilities of further enhancing EVs' innate protective qualities. Our findings underscore the need for further research to optimize the therapeutic potential of EVs and establish their efficacy and safety in clinical settings.

Stabilizing milk-derived extracellular vesicles (mEVs) through lyophilization: a novel trehalose and tryptophan formulation for maintaining structure and Bioactivity during long-term storage

Extracellular vesicles (EVs) are widely investigated for their implications in cell-cell signaling, immune modulation, disease pathogenesis, cancer, regenerative medicine, and as a potential drug delivery vector. However, maintaining integrity and bioactivity of EVs between Good Manufacturing Practice separation/filtration and end-user application remains a consistent bottleneck towards commercialization. Milk-derived extracellular vesicles (mEVs), separated from bovine milk, could provide a relatively low-cost, scalable platform for large-scale mEV production; however, the reliance on cold supply chain for storage remains a logistical and financial burden for biologics that are unstable at room temperature. Herein, we aim to characterize and engineer a freeze-dried, mEV formulation that can be stored at room temperature without sacrificing structure/bioactivity and can be reconstituted before delivery. In addition to undertaking established mEV assays of structure and function on our preparations, we introduce a novel, efficient, high throughput assay of mEV bioactivity based on Electric Cell Substrate Impedance Sensing (ECIS) in Human dermal fibroblast monolayers. By adding appropriate excipients, such as trehalose and tryptophan, we describe a protective formulation that preserves mEV bioactivity during long-term, room temperature storage. Our identification of the efficacy of tryptophan as a novel additive to mEV lyophilization solutions could represent a significant advancement in stabilizing small extracellular vesicles outside of cold storage conditions.

Potential of Plant-derived Exosome-like Nanoparticles from Physalis peruviana Fruit for Human Dermal Fibroblast Regeneration and Remodeling

AIMS

This research aimed to study the potential of PDEN from P. peruviana fruits (PENC) for regenerating and remodeling HDF.

BACKGROUND

Large wounds are dangerous and require prompt and effective healing. Various efforts have been undertaken, but have been somewhat ineffective. Plant-derived exosome-like nanoparticles (PDEN) are easily sampled, relatively cost-effective, exhibit high yields, and are nonimmunogenic.

OBJECTIVES

The objective of the study was to isolate and characterize PDEN from Physalis peruviana (PENC), and determine PENC's internalization and toxicity on HDF cells, PENC's ability to regenerate HDF (proliferation and migration), and PENC ability's to remodel HDF (collagen I and MMP-1 production).

METHODS

PENC was isolated using gradual filtration and centrifugation, followed by sedimentation using PEG6000. Characterization was done using a particle size analyzer, zeta potential analyzer, TEM, and BCA assay. Internalization was done using PKH67 staining. Toxicity and proliferation assays were conducted using MTT assay; meanwhile, migration assay was carried out by employing the scratch assay. Collagen I production was performed using immunocytochemistry and MMP-1 production was conducted using ELISA.

RESULTS

MTT assay showed a PENC concentration of 2.5 until 500 μg/mL and being non-toxic to cells. PENC has been found to induce cell proliferation in 1, 3, 5, and 7 days. PENC at a concentration of 2.5, 5, and 7.5 μg/mL, also accelerated HDF migration using the scratch assay in two days. In remodeling, PENC upregulated collagen-1 expression from day 7 to 14 compared to control. MMP-1 declined from day 2 to 7 in every PENC concentration and increased on day 14. Overall, PENC at concentrations of 2.5, 5, and 7.5 μg/mL induced HDF proliferation and migration, upregulated collagen I production, and decreased MMP-1 levels.

CONCLUSION

Isolated PENC was 190-220 nm in size, circular, covered with membrane, and its zeta potential was -6.7 mV; it could also be stored at 4°C for up to 2 weeks in aqua bidest. Protein concentration ranged between 170-1,395 μg/mL. Using PKH67, PENC could enter HDF within 6 hours. PENC was non-toxic up to a concentration of 500 μg/mL. Using MTT and scratch assay, PENC was found to elevate HDF proliferation and migration, and reorganize actin. Using immunocytochemistry, collagen I was upregulated by PENC, whereas MMP-1 concentration was reduced.

Polyelectrolytes Are Effective Cryoprotectants for Extracellular Vesicles

Extracellular vesicles (EVs) have been widely recognized as a heterogeneous group of membrane-coated submicrometer particles released by different types of cells, including stem cells (SCs). Due to their ability to harbor and transfer bioactive cargo into the recipient cells, EVs have been reported as important paracrine factors involved in the regulation of a variety of biological processes. Growing data demonstrate that EVs may serve as potential next-generation cell-free therapeutic factors. However, clinical application of EVs in tissue regeneration requires the development of standardized procedures for their long-term storage, without the loss of structural integrity and biological activity. In the current study, we developed a procedure of EV cryoprotection based on coating them with ultrathin polyelectrolyte bilayer consisting of cationic poly(ethylene glycol)-block- poly(3-(methacryloylamino)propyl)trimethylammonium chloride) (PEGn-b-PMAPTACm) and anionic of poly(2-acrylamido-2-methylpropanesulfonic acid) (PAMPS). Based on the nanoparticle tracking analysis, high-resolution flow cytometry, and mass spectrometry, we studied the vesicle integrity following single- or multiple freezing-thawing cycles and long-term storage. Additionally, we evaluated the effect of cryopreservation on the EVs functional activity in vitro. Obtained data indicate that coating with polyelectrolytes improves the structural integrity of EVs and preserves their biological activity in vitro. Additionally, proteomic analysis confirmed the effect of particle stabilization, as well as an enrichment in EV proteins in samples cryopreserved in the presence of tested polymers. Taking together, our study indicates that the application of polyelectrolytes may be a novel, effective way of facilitating long-term storage of EV preparations for their further use in the biomedical applications.

Application of extracellular vesicles in diabetic osteoporosis

As the population ages, the occurrence of osteoporosis is becoming more common. Diabetes mellitus is one of the factors in the development of osteoporosis. Compared with the general population, the incidence of osteoporosis is significantly higher in diabetic patients. Diabetic osteoporosis (DOP) is a metabolic bone disease characterized by abnormal bone tissue structure due to hyperglycemia and insulin resistance, reduced bone strength and increased risk of fractures. This is a complex mechanism that occurs at the cellular level due to factors such as blood vessels, inflammation, and hyperglycemia and insulin resistance. Although the application of some drugs in clinical practice can reduce the occurrence of DOP, the incidence of fractures caused by DOP is still very high. Extracellular vesicles (EVs) are a new communication mode between cells, which can transfer miRNAs and proteins from mother cells to target cells through membrane fusion, thereby regulating the function of target cells. In recent years, the role of EVs in the pathogenesis of DOP has been widely demonstrated. In this article, we first describe the changes in the bone microenvironment of osteoporosis. Second, we describe the pathogenesis of DOP. Finally, we summarize the research progress and challenges of EVs in DOP.

Exosomal therapy is a luxury area for regenerative medicine

Stem cell-based therapies have made significant advancements in tissue regeneration and medical engineering. However, there are limitations to cell transplantation therapy, such as immune rejection and limited cell viability. These limitations greatly impede the translation of stem cell-based tissue regeneration into clinical practice. In recent years, exosomes, which are packaged vesicles released from cells, have shown promising progress. Specifically, exosomes derived from stem cells have demonstrated remarkable therapeutic benefits. Exosomes are nanoscale extracellular vesicles that act as paracrine mediators. They transfer functional cargos, such as miRNA and mRNA molecules, peptides, proteins, cytokines, and lipids, from MSCs to recipient cells. By participating in intercellular communication events, exosomes contribute to the healing of injured or diseased tissues and organs. Studies have shown that the therapeutic effects of MSCs in various experimental paradigms can be solely attributed to their exosomes. Consequently, MSC-derived exosomes can be modified and utilized to develop a unique cell-free therapeutic approach for treating multiple diseases, including neurological, immunological, heart, and other diseases. This review is divided into several categories, including the current understanding of exosome biogenesis, isolation techniques, and their application as therapeutic tools.

Different storage and freezing protocols for extracellular vesicles: a systematic review

BACKGROUND

Extracellular vesicles (EVs) have been considered promising tools in regenerative medicine. However, the nanoscale properties of EVs make them sensitive to environmental conditions. Optimal storage protocols are crucial for maintaining EV structural, molecular, and functional integrity. This systematic review aimed to gather evidence on the effects of various storage protocols on EV characteristics and integrity.

STRATEGY

A comprehensive search was conducted for original studies investigating the impacts of storage temperature, freezing techniques, freeze-thaw cycles, and stabilizing strategies on EV concentration, size distribution, morphology, cargo content, and bioactivity. Results from 50 included studies were analyzed.

RESULTS

Data indicated that rapid freezing procedures and constant subzero temperatures (optimally - 80 °C) resulted in appropriate EV quantity and cargo preservation. Subjecting EVs to multiple freeze-thaw cycles decreased particle concentrations, RNA content, impaired bioactivity, and increased EV size and aggregation. Electron microscopy revealed vesicle enlargement, and fusion, along with membrane deformation after being exposed to substandard storage protocols. The addition of stabilizers like trehalose helped EVs to maintain integrity. Of note, storage in native biofluids offered improved stability over purified EVs in buffers.

CONCLUSION

Data emphasize the critical need for precise storage protocols for EVs to ensure reproducible research outcomes and clinical applications. Further studies using reliable methods are necessary to create specific guidelines for improving the stability of EVs in various applications.

Unlocking the potential of Cupriavidus necator H16 as a platform for bioproducts production from carbon dioxide

The rapid global increase in fossil fuel and energy consumption has resulted in the accumulation of greenhouse gases, especially carbon dioxide (CO2), thus contributing to climate change. Therefore, transforming CO2 into valuable products could yield beneficial outcomes. In this review, the capabilities of Cupriavidus necator H16, a light-independent chemoautotrophic bacterium, as a host platform for the transformation of CO2 into diverse products are explored. We begin by examining the progress in synthetic biology toolkits, gas fermentation technologies, and engineering approaches, considering the chemoautotrophic metabolic traits of C. necator to enhance the capacity of the strain for CO2 fixation. Additionally, recent research focused on the metabolic engineering of C. necator H16 for the conversion of CO2 into biodegradable plastics, biofuels, bioactive compounds, and single-cell proteins was reviewed. Finally, we address the limitations affecting the advancement and utilization of C. necator H16 strain, such as inefficiencies and the range of product types, and offer several recommendations for enhancement. This review acts as a resource for the development of C. necator H16 cell factories and the industrial manufacture of products derived from CO2.

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.

Spheroid-Exosome-Based Bioprinting Technology in Regenerative Medicine

Since the discovery that exosomes can exchange genes, their potential use as tools for tissue regeneration, disease diagnosis, and therapeutic applications has drawn significant attention. Emerging three-dimensional (3D) printing technologies, such as bioprinting, which allows the printing of cells, proteins, DNA, and other biological materials, have demonstrated the potential to create complex body tissues or personalized 3D models. The use of 3D spheroids in bioprinting facilitates volumetric tissue reconstruction and accelerates tissue regeneration via exosome secretion. In this review, we discussed a convergence approach between two promising technologies for bioprinting and exosomes in regenerative medicine. Among the various 3D cell culture methods used for exosome production, we focused on spheroids, which are suitable for mass production by bioprinting. We then summarized the research results on cases of bioprinting applications using the spheroids and exosomes produced. If a large number of spheroids can be supplied through bioprinting, the spheroid-exosome-based bioprinting technology will provide new possibilities for application in tissue regeneration, disease diagnosis, and treatment.

Plant-Derived Exosome-like Nanoparticles: A Comprehensive Overview of Their Composition, Biogenesis, Isolation, and Biological Applications

Plant-derived exosome-like nanoparticles (PELNs) are a type of membranous vesicle isolated from plant tissues. They contain proteins, lipids, nucleic acids, and other components. PELNs are involved in the defensive response to pathogen attacks by exerting anti-inflammatory, antiviral, antifibrotic, and antitumor effects through the substances they contain. Most PELNs are edible and can be used as carriers for delivering specific drugs without toxicity and side effects, making them a hot topic of research. Sources of PELNs are abundantly, and they can be produced in high yields, with a low risk of developing immunogenicity in vivo. This paper summarizes the formation, isolation, and purification methods; physical properties; and composition of PELNs through a comprehensive literature search. It also analyzes the biomedical applications of PELNs, as well as future research directions. This paper provides new ideas and methods for future research on PELNs.

Extracellular vesicles from microglial cells activated by abnormal heparan sulfate oligosaccharides from Sanfilippo patients impair neuronal dendritic arborization

BACKGROUND

In mucopolysaccharidosis type III (MPS III, also known as Sanfilippo syndrome), a pediatric neurodegenerative disorder, accumulation of abnormal glycosaminoglycans (GAGs) induces severe neuroinflammation by triggering the microglial pro-inflammatory cytokines production via a TLR4-dependent pathway. But the extent of the microglia contribution to the MPS III neuropathology remains unclear. Extracellular vesicles (EVs) mediate intercellular communication and are known to participate in the pathogenesis of adult neurodegenerative diseases. However, characterization of the molecular profiles of EVs released by MPS III microglia and their effects on neuronal functions have not been described.

METHODS

Here, we isolated EVs secreted by the microglial cells after treatment with GAGs purified from urines of Sanfilippo patients (sfGAGs-EVs) or from age-matched healthy subjects (nGAGs-EVs) to explore the EVs' proteins and small RNA profiles using LC-MS/MS and RNA sequencing. We next performed a functional assay by immunofluorescence following nGAGs- or sfGAGs-EVs uptake by WT primary cortical neurons and analyzed their extensions metrics after staining of βIII-tubulin and MAP2 by confocal microscopy.

RESULTS

Functional enrichment analysis for both proteomics and RNA sequencing data from sfGAGs-EVs revealed a specific content involved in neuroinflammation and neurodevelopment pathways. Treatment of cortical neurons with sfGAGs-EVs induced a disease-associated phenotype demonstrated by a lower total neurite surface area, an impaired somatodendritic compartment, and a higher number of immature dendritic spines.

CONCLUSIONS

This study shows, for the first time, that GAGs from patients with Sanfilippo syndrome can induce microglial secretion of EVs that deliver a specific molecular message to recipient naive neurons, while promoting the neuroinflammation, and depriving neurons of neurodevelopmental factors. This work provides a framework for further studies of biomarkers to evaluate efficiency of emerging therapies.

A negative regulatory role of β-cell-derived exosomes in the glucose-stimulated insulin secretion of recipient β-cells

Exosomes are extracellular vesicles that play a role in intercellular communication through the transportation of their cargo including mRNAs, microRNAs, proteins, and nucleic acids. Exosomes can also regulate glucose homeostasis and insulin secretion under diabetic conditions. However, the role of exosomes in insulin secretion in islet β-cells under physiological conditions remains to be clarified. The aim of this study was to investigate whether exosomes derived from pancreatic islet β-cells could affect insulin secretion in naïve β-cells. We first confirmed that exosomes derived from the RIN-m5f β-cell line interfered with the glucose-stimulated insulin secretion (GSIS) of recipient β-cells without affecting cell viability. The exosomes significantly reduced the protein expression levels of phosphorylated Akt, phosphorylated GSK3α/β, CaMKII, and GLUT2 (insulin-related signaling molecules), and they increased the protein expression levels of phosphorylated NFκB-p65 and Cox-2 (inflammation-related signaling molecules), as determined by a Western blot analysis. A bioinformatics analysis of Next-Generation Sequencing data suggested that exosome-carried microRNAs, such as miR-1224, -122-5p, -133a-3p, -10b-5p, and -423-5p, may affect GSIS in recipient β-cells. Taken together, these findings suggest that β-cell-derived exosomes may upregulate exosomal microRNA-associated signals to dysregulate glucose-stimulated insulin secretion in naïve β-cells.

Orthobiologic Products: Preservation Options for Orthopedic Research and Clinical Applications

The biological products used in orthopedics include musculoskeletal allografts-such as bones, tendons, ligaments, and cartilage-as well as biological therapies. Musculoskeletal allografts support the body's healing process by utilizing preserved and sterilized donor tissue. These allografts are becoming increasingly common in surgical practice, allowing patients to avoid more invasive procedures and the risks associated with donor site morbidity. Bone grafting is one of the most frequently used procedures in orthopedics and traumatology. Biologic approaches aim to improve clinical outcomes by enhancing the body's natural healing capacity and reducing inflammation. They serve as an alternative to surgical interventions. While preliminary results from animal studies and small-scale clinical trials have been promising, the field of biologics still lacks robust clinical evidence supporting their efficacy. Biological therapies include PRP (platelet-rich plasma), mesenchymal stem cells (MSCs)/stromal cells/progenitor cells, bone marrow stem/stromal cells (BMSCs), adipose stem/stromal cells/progenitor cells (ASCs), cord blood (CB), and extracellular vesicles (EVs), including exosomes. The proper preservation and storage of these cellular therapies are essential for future use. Preservation techniques include cryopreservation, vitrification, lyophilization, and the use of cryoprotective agents (CPAs). The most commonly used CPA is DMSO (dimethyl sulfoxide). The highest success rates and post-thaw viability have been achieved by preserving PRP with a rate-controlled freezer using 6% DMSO and storing other cellular treatments using a rate-controlled freezer with 5% or 10% DMSO as the CPA. Extracellular vesicles (EVs) have shown the best results when lyophilized with 50 mM or 4% trehalose to prevent aggregation and stored at room temperature.

Exosome-based cell therapy for diabetic foot ulcers: Present and prospect

Diabetic foot ulcers (DFUs) represent a serious complication of diabetes with high incidence, requiring intensive treatment, prolonged hospitalization, and high costs. It poses a severe threat to the patient's life, resulting in substantial burdens on patient and healthcare system. However, the therapy of DFUs remains challenging. Therefore, exploring cell-free therapies for DFUs is both critical and urgent. Exosomes, as crucial mediators of intercellular communication, have been demonstrated potentially effective in anti-inflammation, angiogenesis, cell proliferation and migration, and collagen deposition. These functions have been proven beneficial in all stages of diabetic wound healing. This review aims to summarize the role and mechanisms of exosomes from diverse cellular sources in diabetic wound healing research. In addition, we elaborate on the challenges for clinical application, discuss the advantages of membrane vesicles as exosome mimics in wound healing, and present the therapeutic potential of exosomes and their mimetic vesicles for future clinical applications.

Encapsulation of telmisartan inside insulinoma-cell-derived extracellular vesicles outperformed biomimetic nanovesicles in modulating the pancreatic inflammatory microenvironment

Diabetes mellitus (DM) is a chronic metabolic condition, characterized by hyperglycaemia, oxidative imbalance, pancreatic β-cell death, and insulin insufficiency. Angiotensin II (Ang II) increases oxidative stress, inflammation, and apoptosis, and Ang II type 1 receptor (AT1R) blockers (ARBs) can ameliorate inflammatory response and oxidative stress. However, like other small-molecule drugs, free ARBs show poor in vivo efficacy and dose-limiting toxicities. Hence, in this study, we developed nano-formulations of telmisartan (TEL), an ARB, by encapsulating it inside a murine insulinoma cell-derived extracellular vesicle (nanoTEL) and a bio-mimetic lipid nanovesicle (lipoTEL). Both nano-formulations showed spherical morphology and sustained release of TEL. In vitro, nanoTEL restored oxidative equilibrium, attenuated reactive oxygen species levels, enhanced the uptake of glucose analogue, and increased the expression of glucose transporter protein 4 better than lipoTEL. In a streptozotocin-induced murine model of diabetes, nanoTEL lowered blood glucose levels, improved glucose tolerance, and promoted insulin synthesis and secretion significantly better than lipoTEL. Moreover, nanoTEL was found superior in ameliorating the pancreatic inflammatory microenvironment by regulating NF-κBp65, HIF-1α, and PPAR-γ expression; modulating IL-1β, IL-6, tumor necrosis factor-α, IL-10, and IL-4 levels and inducing the polarization of macrophage from M1 to M2. Further, nanoTEL administration induced angiogenesis and promoted the proliferation of pancreatic cells to restore the structural integrity of the islets of Langerhans more efficiently than lipoTEL. These findings collectively suggest that nanoTEL outperforms lipoTEL in restoring the function of pancreatic β-cells by modulating the pancreatic inflammatory microenvironment and show potential for the treatment of DM.

MicroRNA-based engineered mesenchymal stem cell extracellular vesicles to treat visual deficits after blast-induced trauma

Our previous studies have shown the benefit of intravitreal injection of a mesenchymal stem cell (MSC)- derived secretome to treat visual deficits in a mild traumatic brain injury (mTBI) mouse model. In this study, we have addressed whether MSC-derived extracellular vesicles (EV) overexpressing miR424, which particularly targets neuroinflammation, show similar benefits in the mTBI model. Adult C57BL/6 mice were subjected to a 50-psi air pulse on the left side, overlying the forebrain, resulting in mTBI. Sham-blast mice were controls. Within an hour of blast injury, 3 μl (∼7.5 × 108 particles) of miR424-EVs, native-EVs, or saline was delivered intravitreally. One month later, retinal morphology was observed through optical coherence tomography (OCT); visual function was assessed using optokinetic nystagmus (OKN) and electroretinogram (ERG), followed by immunohistological analysis. A separate study in adult mice tested the dose-response of EVs for safety. Blast injury mice with saline showed decreased visual acuity compared with the sham group (0.30 ± 0.03 vs. 0.39 ± 0.01 c/d, p < 0.02), improved with miR424-EVs (0.39 ± 0.02 c/d, p < 0.01) but not native-EVs (0.33 ± 0.04 c/d, p > 0.05). Contrast sensitivity thresholds of blast mice receiving saline increased compared with the sham group (85.3 ± 5.9 vs. 19.9 ± 4.8, %, p < 0.001), rescued by miR424-EVs (23.6 ± 7.3 %, p < 0.001) and native-EVs (45.6 ± 10.7 %, p < 0.01). Blast injury decreased "b" wave amplitude compared to sham mice (94.6 ± 24.0 vs. 279.2 ± 25.3 μV, p < 0.001), improved with miR424-EVs (173.0 ± 27.2 μV, p < 0.03) and native-EVs (230.2 ± 37.2 μV, p < 0.01) with a similar decrease in a-wave amplitude in blast mice improved with both miR424-EVs and native-EVs. Immunohistology showed increased GFAP and IBA1 in blast mice with saline compared with sham (GFAP: 11.9 ± 1.49 vs. 9.1 ± 0.8, mean intensity/100,000 μm2 area, p < 0.03; IBA1: 36.08 ± 4.3 vs. 24.0 ± 1.54, mean intensity/100,000 μm2 area, p < 0.01), with no changes with native-EVs (GFAP: 12.6 ± 0.79, p > 0.05; IBA1: 32.8 ± 2.9, p > 0.05), and miR424-EV (GFAP: 13.14 ± 0.76, p > 0.05; IBA1: 31.4 ± 2.7, p > 0.05). Both native-EVs and miR424-EVs exhibited vitreous aggregation, as evidenced by particulates in the vitreous by OCT, and increased vascular structures, as evidenced by αSMA and CD31 immunostainings. The number of capillary lumens in the ganglion cell layer increased with increased particles in the eye, with native EVs showing the worst effects. In conclusion, our study highlights the promise of EV-based therapies for treating visual dysfunction caused by mTBI, with miR424-EVs showing particularly strong neuroprotective benefits. Both miR424-EVs and native-EVs provided similar protection, but issues with EV aggregation and astrogliosis or microglial/macrophage activation at the current dosage call for improved delivery methods and dosage adjustments. Future research should investigate the mechanisms behind EVs' effects and optimize miR424 delivery strategies to enhance therapeutic outcomes and reduce complications.

Functional dry powders of connexin-containing extracellular vesicles

Extracellular vesicles (EVs) have emerged as a promising drug delivery system. Connectosomes are a specialized type of EVs that contain connexins in their membranes. Connexin is a surface transmembrane protein that forms connexin hemichannels. When a connexin hemichannel on a connectosome docks with another connexin hemichannel of a target cell, they form a gap junction that allows direct intracellular delivery of therapeutic cargos from within the connectosome to the cytoplasm of the recipient cell. In the present study, we tested the feasibility of converting connectosomes into dry powders by (thin-film) freeze-drying to enable their potential storage in temperatures higher than the recommended -80 °C, while maintaining their activity. Connectosomes were isolated from a genetically engineered HeLa cell line that overexpressing connexin-43 subunit protein tagged with red fluorescence protein. To facilitate the testing of the function of the connectosomes, they were loaded with calcein green dye. Calcein green-loaded connectosomes were thin-film freeze-dried with trehalose alone or trehalose and a polyvinylpyrrolidone polymer as lyoprotectant(s) to produce amorphous powders with high glass transition temperatures (>100 °C). Thin-film freeze-drying did not significantly change the morphology and structure of the connectosomes, nor their particle size distribution. Based on data from confocal microscopy, flow cytometry, and fluorescence spectrometry, the connexin hemichannels in the connectosomes reconstituted from the thin-film freeze-dried powder remained functional, allowing the passage of calcein green through the hemichannels and the release of the calcein green from the connectosomes when the channels were opened by chelating calcium in the reconstituted medium. The function of connectosomes was assessed after one month storage at different temperatures. The connexin hemichannels in connectosomes in liquid lost their function when stored at -19.5 ± 2.2 °C or 6.0 ± 0.5 °C for a month, while those in dry powder form remained functional under the same storage conditions. Finally, using doxorubicin-loaded connectosomes, we showed that the connectosomes reconstituted from thin-film freeze-dried powder remained pharmacologically active. These findings demonstrate that (thin-film) freeze-drying represents a viable method to prepare stable and functional powders of EVs that contain connexins in their membranes.

Hybrid hair follicle stem cell extracellular vesicles co-delivering finasteride and gold nanoparticles for androgenetic alopecia treatment

Androgenetic alopecia (AGA) is a non-fatal disease prevalent worldwide. However, mixed efficacy has been observed among different therapies for hair regrowth in AGA patients. Thus, a nano-platform with synergistic treatments based on a hybrid extracellular vesicle encapsulating gold nanoparticles (AuNPs) and finasteride (Hybrid/Au@Fi) was constructed through membrane fusion between hair follicle stem cell (HFSC)-derived extracellular vesicles and liposomes. These hybrid vesicles (HVs) not only fuel hair regrowth by providing cellular signals in extracellular vesicles, but also improve storage stability, follicle retention, and drug encapsulation efficiency (EE%) for finasteride inhibiting 5α-reductase, and nano-size AuNPs that simulate low-level laser therapy (LLLT) with similar photothermal effects in vitro. The EE% of finasteride in these HVs reached 45.33%. The dual administration of these extracellular vesicles and finasteride showed a strong synergistic effect on HFSCs in vitro. In an AGA mouse model, once-daily topical Hybrid/Au@Fi (115.07 ± 0.32 nm, -7.50 ± 1.68 mV) gel led to a faster transition of hair follicles (HFs) from the catagen to the anagen, increased hair regrowth coverage, and higher quality of regrowth hair, compared to once-daily 5% minoxidil treatment. Compared to topical minoxidil, the multifaceted synergistic therapy of Hybrid/Au@Fi through topical administration offers a new option for intractable AGA patients with low side effects.

Evaluating stability and bioactivity of Rehmannia-derived nanovesicles during storage

Plant-derived nanovesicles (PDNVs) have garnered growing attention in the biomedical field owing to their abundance in plant-derived ribonucleic acids (RNA), proteins, lipids and metabolites. The question about the preservation of PDNVs is a crucial and unavoidable concern in both experiments' settings and their potential clinical application. The objective of this research was to examine the impact of varying storage temperatures on the stability and bioactivity of Rehmannia-derived nanovesicles (RDNVs). The results showed that RDNVs aggregated after 2 weeks of storage period at 4 °C, and the particle size of some RDNVs gradually increased with time, along with the increase of solution potential. After 2 months of storage, all RDNVs exhibited varying levels of aggregation irrespective of storage temperature. The bioactivities of nanovesicles under different temperature storage conditions revealed a gradual decline in cell proliferation inhibition bioactivity over time, significantly lower than that of freshly prepared RDNVs. In contrast, the preservation of anti-migratory activity in RDNVs was found to be more effective when subjected to rapid freezing in liquid nitrogen followed by storage at - 80 °C, as opposed to direct storage at - 80 °C. These findings suggest that temperature alone may not be sufficient in safeguarding the activity and stability of RDNVs, highlighting the necessity for the development of novel protective agents for PDNVs.

Cryopreserved nanostructured fibrin-agarose hydrogels are efficient and safe hemostatic agents

Uncontrolled bleeding during surgery is associated with high mortality and prolonged hospital stay, necessitating the use of hemostatic agents. Fibrin sealant patches offer an efficient solution to achieve hemostasis and improve patient outcomes in liver resection surgery. We have previously demonstrated the efficacy of a nanostructured fibrin-agarose hydrogel (NFAH). However, for the widespread distribution and commercialization of the product, it is necessary to develop an optimal preservation method that allows for prolonged stability and facilitates storage and distribution. We investigated cryopreservation as a potential method for preserving NFAH using trehalose. Structural changes in cryopreserved NFAH (Cryo-NFAH) were investigated and comparative in vitro and in vivo efficacy and safety studies were performed with freshly prepared NFAH. We also examined the long-term safety of Cryo-NFAH versus TachoSil in a rat partial hepatectomy model, including time to hemostasis, intra-abdominal adhesion, hepatic hematoma, inflammatory factors, histopathological variables, temperature and body weight, hemocompatibility and cytotoxicity. Structural analyses demonstrated that Cryo-NFAH retained most of its macro- and microscopic properties after cryopreservation. Likewise, hemostatic efficacy assays showed no significant differences with fresh NFAH. Safety evaluations indicated that Cryo-NFAH had a similar overall profile to TachoSil up to 40 days post-surgery in rats. In addition, Cryo-NFAH demonstrated superior hemostatic efficacy compared with TachoSil while also demonstrating lower levels of erythrolysis and cytotoxicity than both TachoSil and other commercially available hemostatic agents. These results indicate that Cryo-NFAH is highly effective hemostatic patch with a favorable safety and tolerability profile, supporting its potential for clinical use.

Investigation of on-line electrokinetic enrichment strategies for capillary electrophoresis of extracellular vesicles

This work explores strategies for electrokinetic preconcentration of extracellular vesicles (EVs) that are potential source of biomarkers for different diseases. The first approach that led to successful preconcentration of EVs is based on large volume sample stacking (LVSS), allowing an enrichment factor of 7 for CE of EVs with long-end injection (using a capillary with an effective length of 50 cm). Attempts were also made to perform multiple cycles of LVSS, field amplified sample stacking (FASS) and field amplified sample injection (FASI), to improve EVs preconcentration performance. The focus was then put on development of capillary isotachophoresis under high ionic strengths (IS) for electrokinetic enrichment of slow migrating EVs having heterogeneous mobilities. This approach relies on the use of extremely high concentrations of the terminating electrolyte (TE) to slow down the mobility of TE co-ions, rendering them slower than those of EVs. The limit of detection for intact EVs using the developed ITP-UV method reached 8.3 × 108 EVs/mL, allowing an enrichment of 25 folds and a linear calibration up to 4 × 1010 EVs/mL. The ITP-UV and ITP-LIF approaches were applied to provide the electrokinetic signature of EVs of bovine milk and human plasma as well as to visualize more specifically intravesicular fluorescently labelled EVs. The investigation of these strategies shredded light into the challenges still encountered with electrokinetic preconcentration and separation of heterogeneous EVs sub-populations which are discussed herein based on our results and other attempts reported in the literature.

Immunogenicity of Extracellular Vesicles

Extracellular vesicles (EVs) are promising next-generation therapeutics and drug delivery systems due to demonstrated safety and efficacy in preclinical models and early-stage clinical trials. There is an urgent need to address the immunogenicity of EVs (beyond the apparent lack of immunotoxicity) to advance clinical development. To date, few studies have assessed unintended immunological recognition of EVs. An in-depth understanding of EV-induced immunogenicity and clearance is necessary to develop effective therapeutic strategies, including approaches to mitigate immunological recognition when undesired. This article summarizes various factors involved in the potential immunogenicity of EVs and strategies to reduce immunological recognition for improved therapeutic benefit.

Multi-layered metabolic effects of trehalose on the liver proteome in apoE-knockout mice model of liver steatosis

BACKGROUND

Metabolic dysfunction-associated fatty liver disease has been well documented as a key independent risk factor for the development of atherosclerosis. A growing body of evidence suggests that due to its numerous favorable molecular effects, trehalose may exert beneficial effects in counteracting liver steatosis. In our previous study, we described the antiatherosclerotic and antisteatotic properties of trehalose, which we attributed to the induction of autophagy. Considering the pleiotropic activities of trehalose, our present study aimed to extend our preliminary results with the comprehensive examination of proteome-wide changes in the livers of high-fat-fed apoE-/- mice.

METHODS

Thus, we applied modern, next-generation proteomic methodology to comprehensively analyze the effects of trehalose on the alterations of liver proteins in apoE-/- mice.

RESULTS

Our proteomic analysis showed that the administration of trehalose elicited profound changes in the liver proteome of apoE-/- mice. The collected data allowed the identification and quantitation of 3 681 protein groups of which 129 were significantly regulated in the livers of trehalose-treated apoE-/- mice.

CONCLUSIONS

The presented results are the first to highlight the effects of disaccharide on the induction of proteins mainly related to the metabolism and elimination of lipids, especially by peroxisomal β-oxidation. Our study provides evidence for the pleiotropic activity of trehalose, extending our initial observations of its potential mechanisms responsible for mitigating of liver steatosis, which paves the way for new pharmacological strategies in fatty liver disease.

Therapeutic Effects of Mesenchymal Stem Cell-Derived Extracellular Vesicles in sepsis: a Systematic Review and Meta-Analysis of Preclinical Studies

BACKGROUND

Sepsis is a life-threatening disorder with no definitive cure. Preclinical studies suggest that extracellular vesicles derived from mesenchymal stromal cells (EV-MSCs) can mitigate inflammatory conditions, potentially leading to increased survival and reduced organ dysfunction during sepsis. Our aim to conduct this systematic review and meta-analysis is assessing the EV-MSCs therapeutic efficacy in sepsis.

METHODS

PubMed, Embase, Scopus, WOS and ProQuest databases and also Google Scholar search engine were searched for published articles. We used hazard ratio (HR) and standardized mean difference (SMD) as effect sizes to evaluate the therapeutic effect of EV-MSCs on survival rate and determine their effect on reducing organ dysfunction, respectively. Finally, we employed GRADE tool for preclinical animal studies to evaluate certainty of the evidence.

RESULTS

30 studies met the inclusion criteria for our article. Our meta-analysis results demonstrate that animals treated with MSC-EVs have better survival rate than untreated animals (HR = 0.33; 95% CI: 0.27-0.41). Our meta-analysis suggests that EV-MSCs can reduce organ dysfunctions in sepsis, such as the lung, kidney, and liver. Additionally, EV-MSCs decrease pro-inflammatory mediators like TNF-α, IL-1β, and IL-6.

CONCLUSION

Our results indicate that EV-MSCs can be as promising therapy for sepsis management in animal models and leading to increased survival rate and reduced organ dysfunction. Furthermore, our study introduces a novel tool for risk of bias assessment and provides recommendations based on various analysis. Future studies with aiming to guide clinical translation can utilize the results of this article to establish stronger evidence for EV-MSC effectiveness.

The Increasing Diagnostic Role of Exosomes in Inflammatory Diseases to Leverage the Therapeutic Biomarkers

Inflammatory diseases provide substantial worldwide concerns, affecting millions of people and healthcare systems by causing ongoing discomfort, diminished quality of life, and increased expenses. In light of the progress made in treatments, the limited effectiveness and negative side effects of present pharmaceuticals need a more comprehensive comprehension of the underlying processes in order to develop more precise remedies. Exosomes, which are tiny vesicles that play a vital role in cell communication, have been identified as prospective vehicles for effective delivery of anti-inflammatory medicines, immunomodulators, and gene treatments. Vesicles, which are secreted by different cells, have a crucial function in communicating between cells. This makes them valuable in the fields of diagnostics and therapies, particularly for inflammatory conditions. Exosomes have a role in regulating the immune system, transporting cytokines, and influencing cell signaling pathways associated with inflammation. They consist of proteins, lipids, and genetic information that have an impact on immune responses and inflammation. Scientists are now investigating exosomes as biomarkers for inflammatory disease. This review article aims to develop non-invasive diagnostic techniques with improved sensitivity and specificity. Purpose of this review is a thorough examination of exosomes in pharmacology, specifically emphasizing their origin, contents, and functions, with the objective of enhancing diagnostic and therapeutic strategies for inflammatory conditions. Gaining a comprehensive understanding of the intricate mechanisms involved in exosome-mediated interactions and their impact on immune responses is of utmost importance in order to devise novel approaches for tackling inflammatory disease and enhancing patient care.

Isolation and characterization of plant-derived exosome-like nanoparticles from Carica papaya L. fruit and their potential as anti-inflammatory agent

Inflammation is an immune system response that identifies and eliminates foreign material. However, excessive and persistent inflammation could disrupt the healing process. Plant-derived exosome-like nanoparticles (PDENs) are a promising candidate for therapeutic application because they are safe, biodegradable and biocompatible. In this study, papaya PDENs were isolated by a PEG6000-based method and characterized by dynamic light scattering (DLS), transmission Electron Microscopy (TEM), bicinchoninic acid (BCA) assay method, GC-MS analysis, total phenolic content (TPC) analysis, and 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay. For the in vitro test, we conducted internalization analysis, toxicity assessment, determination of nitrite concentration, and assessed the expression of inflammatory cytokine genes using qRT-PCR in RAW 264.7 cells. For the in vivo test, inflammation was induced by caudal fin amputation followed by analysis of macrophage and neutrophil migration in zebrafish (Danio rerio) larvae. The result showed that papaya PDENs can be well isolated using the optimized differential centrifugation method with the addition of 30 ppm pectolyase, 15% PEG, and 0.2 M NaCl, which exhibited cup-shaped and spherical morphological structure with an average diameter of 168.8±9.62 nm. The papaya PDENs storage is stable in aquabidest and 25 mM trehalose solution at -20˚C until the fourth week. TPC estimation of all papaya PDENs ages did not show a significant change, while the DPPH test exhibited a significant change in the second week. The major compounds contained in Papaya PDENs is 2,3-dihydro-3,5-dihydroxy-6-methyl-4H-pyran-4-one (DDMP). Papaya PDENs can be internalized and is non-cytotoxic to RAW 264.7 cells. Moreover, LPS-induced RAW 264.7 cells treated with papaya PDENs showed a decrease in NO production and downregulation mRNA expression of pro-inflammatory cytokine genes (IL-1B and IL-6) and an upregulation in mRNA expression of anti-inflammatory cytokine gene (IL-10). In addition, in vivo tests conducted on zebrafish treated with PDENs papaya showed inhibition of macrophage and neutrophil cell migration. These findings suggest that PDENs papaya possesses anti-inflammatory properties.

Most recent advances and applications of extracellular vesicles in tackling neurological challenges

Over the past few decades, there has been a notable increase in the global burden of central nervous system (CNS) diseases. Despite advances in technology and therapeutic options, neurological and neurodegenerative disorders persist as significant challenges in treatment and cure. Recently, there has been a remarkable surge of interest in extracellular vesicles (EVs) as pivotal mediators of intercellular communication. As carriers of molecular cargo, EVs demonstrate the ability to traverse the blood-brain barrier, enabling bidirectional communication. As a result, they have garnered attention as potential biomarkers and therapeutic agents, whether in their natural form or after being engineered for use in the CNS. This review article aims to provide a comprehensive introduction to EVs, encompassing various aspects such as their diverse isolation methods, characterization, handling, storage, and different routes for EV administration. Additionally, it underscores the recent advances in their potential applications in neurodegenerative disorder therapeutics. By exploring their unique capabilities, this study sheds light on the promising future of EVs in clinical research. It considers the inherent challenges and limitations of these emerging applications while incorporating the most recent updates in the field.