Biocompatibility of highly purified bovine milk-derived extracellular vesicles

Enhanced antibacterial activity of bovine milk exosome-based drug formulation against bacterial pathogens

Milk is not only a source of nutrients, but also contains exosomes (Exo) that can serve as a vehicle for drug delivery. Here, we obtained bovine milk Exo using three efficient methods, demonstrating high quality for commercial production. The optimized Exo displayed a size of 105.2 nm and an entrapment efficiency of 88.4 %. The Exo has been functionalized with a combination therapy comprising isobavachalcone (IS) and polymyxin B (PB), referred to as IP-Exo. The antibacterial efficacy of IP-Exo was significantly enhanced, enabling the elimination of 99 % of multidrug-resistant (MDR) bacterial pathogens in 4 h. Furthermore, scanning electron microscopy images demonstrated that the drug combination led to the complete dismantling of the bacterial structure. IP-Exo showed nearly 100 % microbial inhibition in fresh orange juice and accelerated wound healing in mouse models. Collectively, IP-Exo provides excellent potential for application within the food industry and animal husbandry as a defense against bacterial pathogens.

Phospholipid-Anchored Ligand Conjugation on Extracellular Vesicles for Enhanced Cancer Targeting

Extracellular vesicles (EVs) are recognized as potential candidates for next-generation drug delivery systems. However, the inherent cancer-targeting efficiency is unsatisfactory, necessitating surface modification to attach cell-binding ligands. By utilizing phospholipase D from Streptomyces in combination with maleimide-containing primary alcohol, the authors successfully anchored ligands onto milk-derived EVs (mEVs), overcoming the issues of ligand leakage or functional alteration seen in traditional methods. Quantitative nano-flow cytometry demonstrated that over 90% of mEVs are effectively modified with hundreds to thousands of ligands. The resulting mEV formulations exhibited remarkable long-term stability in conjugation proportion, ligand number, size distribution, and particle concentration, even after months of storage. It is further shown that conjugating transferrin onto mEVs significantly enhanced cellular uptake and induced pronounced cytotoxic effects when loaded with paclitaxel. Overall, this study presents a highly efficient, stable, cost-effective, and scalable ligand conjugation approach, offering a promising strategy for targeted drug delivery of EVs.

Milk-Derived Extracellular Vesicles: Biomedical Applications, Current Challenges, and Future Perspectives

Extracellular vesicles (EVs) are nano to-micrometer-sized sacs that are released by almost all animal and plant cells and act as intercellular communicators by transferring their cargos between the source and target cells. As a safe and scalable alternative to conditioned medium-derived EVs, milk-derived EVs (miEVs) have recently gained a great deal of popularity. Numerous studies have shown that miEVs have intrinsic therapeutic actions that can treat diseases and enhance human health. Additionally, they can be used as natural drug carriers and novel classes of biomarkers. However, due to the complexity of the milk, the successful translation of miEVs from benchtop to bedside still faces several unfilled gaps, especially a lack of standardized protocols for the isolation of high-purity miEVs. In this work, by comprehensively reviewing the bovine miEVs studies, we provide an overview of current knowledge and research on miEVs while highlighting their challenges and enormous promise as a novel class of theranostics. It is hoped that this study will pave the way for clinical applications of miEVs by addressing their challenges and opportunities.

Milk-derived exosome nanovesicles: recent progress and daunting hurdles

Raw milk is the foundation of quality and safety in the dairy industry, and improving milk source management is the fundamental guarantee. Milk-derived exosomes (MDEs) are nanoscale information transfer molecules secreted by mammary cells with unique content and high stability, which can be used not only as potential markers to analyze key traits of lactation, reproduction, nutrition and health of animals, but also help farm managers to take timely interventions to improve animal welfare, milk quality, and functional traits. Our review first outlines the latest advances in MDEs isolation and purification, compositional analysis and characterization tools. We then provide a comprehensive summary of recent applications of MDEs liquid biopsy in breed selection, disease prevention and control, and feeding management. Finally, we evaluate the impact of processing on the stability of MDEs to offer guidance for dairy production and storage. The limitations and challenges in the development and use of MDEs markers are also discussed. As a noninvasive marker with high sensitivity and specificity, the MDEs-mediated assay technology is expected to be a powerful tool for measuring cow health and raw milk quality, enabling dynamic and precise regulation of dairy cows and full traceability of raw milk.

Milk Extracellular Vesicles: Natural Nanoparticles for Enhancing Oral Drug Delivery against Bacterial Infections

Oral drug delivery is typically preferred as a therapeutic intervention due to the complexities and expenses associated with intravenous administration. However, some drugs are poorly absorbed orally, requiring intravenous administration to bypass the gastrointestinal tract and deliver the drug directly into the bloodstream. Thus, there is an urgent need to develop novel drug delivery platforms to overcome the challenges of oral drug delivery with low solubility, low permeability, oral degradation, and low bioavailability. Advances in extracellular vesicles (EVs) as natural carriers have provided emerging approaches to improve potential therapeutic applications. Milk not only contains traditional nutrients but is also rich in EVs. In this Review, we focus mainly on the purification of milk EVs (mEVs), their safety, and the advantages of mEV-based drug carriers in combatting intestinal infections. Additionally, we summarize several advantages of mEVs over conventional synthetic carriers, such as low immunogenicity, high biocompatibility, and the ability to transfer bioactive molecules between cells. Considering the unmet gaps of mEVs in clinical translation, it is essential to review the cargo loading into mEVs and future perspectives for their use as natural drug carriers for oral delivery. This overview of mEV-based drug carriers for oral delivery sheds light on alternative approaches to treat clinical infections associated with intestinal pathogens and the development of novel oral delivery systems.

Deciphering the Drug Delivery Potential of Milk Exosome Nanovesicles for Aminobenzylpenicillin Therapeutic Efficacy against Contagious Staphylococcus Aureus in Bovine Mastitis

The emergence of antimicrobial resistance and failure of antibiotic treatment are challenging tasks for managing bovine mastitis, which is mainly caused by the contagious Staphylococcus aureus (S. aureus).To overcome these difficulties, there is an urgent need for a novel drug system. In the present study, the aim is to develop next-generation therapeutics against S. aureus by harnessing the drug delivery potential of milk nanovesicles called milk exosomes (mENs). In the present work, a drug system is developed by encapsulating aminobenzylpenicillin (AMP) in mENs (mENs-AMP). Electron microscopy and zeta-sizer results indicate that the size of mENs-AMP ranged from 55.79 ± 2.8 to 85.53 ± 7.4 nm. The AMP loading efficiency in mENs is 88.61% with its sustained release. Fluorescence spectroscopy results indicated that mENs are biocompatible with mammary epithelial cells. In vitro studies show that the antibacterial activity and the minimum inhibitory concentrations of mENs-AMP are eleven times greater and four times lower than that of unencapsulated AMP, respectively. The mENs-AMP exhibit significantly higher therapeutic efficacy than AMP at the same dosage and treatment frequency. Validation of this approach is demonstrated in mastitis-affected animals through an observation in the reduction of somatic cell counts and bacterial loads in the milk of treated animals.

Goat milk extracellular vesicles: Separation comparison of natural carriers for theragnostic application

Goat milk is a complex biological fluid, which in addition to having a high nutritional value, it is an interesting source of extracellular vesicles (EVs). Despite the countless potential applications that they offer in many biological fields, is not easy to compare the different proposed systems, and this is a major limitation for the real translatability of these natural nanoplatforms for theragnostic purposes. Thus, it is useful to further investigate reproducible methods to separate goat milk EVs. The choice of methods but also the preprocessing of milk has an immense impact on the separation, quality, and yield of EVs. Here, we tested four protocols to separate EVs from unpasteurised goat milk: two based on differential ultracentrifugation (DUC) and two on size-exclusion chromatography (SEC). Moreover, we assessed two different approaches of pre-treatment (acidification and precipitation) to facilitate milk protein discharge. To the best of our knowledge, a similar comparison of all performed protocols on raw goat milk has never been published before. Therefore, enriched EV samples were successfully obtained from goat milk using both DUC and SEC. Taken together, our results may be helpful to obtain natural carriers for future theragnostic applications in personalised medicine.

Extracellular vesicles from UTX-knockout endothelial cells boost neural stem cell differentiation in spinal cord injury

BACKGROUND

Vascular endothelial cells are pivotal in the pathophysiological progression following spinal cord injury (SCI). The UTX (Ubiquitously Transcribed Tetratripeptide Repeat on Chromosome X) serves as a significant regulator of endothelial cell phenotype. The manipulation of endogenous neural stem cells (NSCs) offers a compelling strategy for the amelioration of SCI.

METHODS

Two mouse models were used to investigate SCI: NSCs lineage-traced mice and mice with conditional UTX knockout (UTX KO) in endothelial cells. To study the effects of UTX KO on neural differentiation, we harvested extracellular vesicles (EVs) from both UTX KO spinal cord microvascular endothelial cells (SCMECs) and negative control SCMECs. These EVs were then employed to modulate the differentiation trajectory of endogenous NSCs in the SCI model.

RESULTS

In our NSCs lineage-traced mice model of SCI, a marked decrease in neurogenesis was observed post-injury. Notably, NSCs in UTX KO SCMECs mice showed enhanced neuronal differentiation compared to controls. RNA sequencing and western blot analyses revealed an upregulation of L1 cell adhesion molecule (L1CAM), a gene associated with neurogenesis, in UTX KO SCMECs and their secreted EVs. This aligns with the observed promotion of neurogenesis in UTX KO conditions. In vivo administration of L1CAM-rich EVs from UTX KO SCMECs (KO EVs) to the mice significantly enhanced neural differentiation. Similarly, in vitro exposure of NSCs to KO EVs resulted in increased activation of the Akt signaling pathway, further promoting neural differentiation. Conversely, inhibiting Akt phosphorylation or knocking down L1CAM negated the beneficial effects of KO EVs on NSC neuronal differentiation.

CONCLUSIONS

In conclusion, our findings substantiate that EVs derived from UTX KO SCMECs can act as facilitators of neural differentiation following SCI. This study not only elucidates a novel mechanism but also opens new horizons for therapeutic interventions in the treatment of SCI. Video Abstract.

Simple methods for measuring milk exosomes using fluorescent compound GIF-2250/2276

Exosomes are small extracellular vesicles (EVs) found in culture supernatants, blood, and breast milk. The size of these nanocomplexes limits the methods of EV analyses. In this study, nitrobenzoxadiazole (NBD), a fluorophore, conjugated endosome-lysosome imager, GIF-2250 and its derivative, GIF-2276, were evaluated for exosome analyses. A correlation was established between GIF-2250 intensity and protein maker levels in bovine milk exosomes. We found that high-temperature sterilization milk may not contain intact exosomes. For precise analysis, we synthesized GIF-2276, which allows for the covalent attachment of NBD to the Lys residue of exosome proteins, and labeled milk exosomes were separated using a gel filtration system. GIF-2276 showed chromatographic peaks of milk exosomes containing >3 ng protein. The area (quantity) and retention time (size) of the exosome peaks were correlated to biological activity (NO synthesis suppression in RAW264.7 murine macrophages). Heat denaturation of purified milk-derived exosomes disrupted these indicators. Proteome analyses revealed GIF-2276-labeled immunomodulators, such as butyrophilin subfamily 1 member A1 and polymeric immunoglobulin receptor. The immunogenicity and quantity of these factors decreased by heat denaturation. When milk exosomes were purified from market-sourced milk we found that raw and low-temperature sterilization milk samples, contained exosomes (none in high-temperature sterilization milk). These results were also supported by transmission electron microscopy analyses. We also found that GIF-2276 could monitor exosome transportation into HEK293 cells. These results suggested that GIF-2250/2276 may be helpful to evaluate milk exosomes.

Extracellular vesicles as tools and targets in therapy for diseases

Extracellular vesicles (EVs) are nano-sized, membranous structures secreted into the extracellular space. They exhibit diverse sizes, contents, and surface markers and are ubiquitously released from cells under normal and pathological conditions. Human serum is a rich source of these EVs, though their isolation from serum proteins and non-EV lipid particles poses challenges. These vesicles transport various cellular components such as proteins, mRNAs, miRNAs, DNA, and lipids across distances, influencing numerous physiological and pathological events, including those within the tumor microenvironment (TME). Their pivotal roles in cellular communication make EVs promising candidates for therapeutic agents, drug delivery systems, and disease biomarkers. Especially in cancer diagnostics, EV detection can pave the way for early identification and offers potential as diagnostic biomarkers. Moreover, various EV subtypes are emerging as targeted drug delivery tools, highlighting their potential clinical significance. The need for non-invasive biomarkers to monitor biological processes for diagnostic and therapeutic purposes remains unfulfilled. Tapping into the unique composition of EVs could unlock advanced diagnostic and therapeutic avenues in the future. In this review, we discuss in detail the roles of EVs across various conditions, including cancers (encompassing head and neck, lung, gastric, breast, and hepatocellular carcinoma), neurodegenerative disorders, diabetes, viral infections, autoimmune and renal diseases, emphasizing the potential advancements in molecular diagnostics and drug delivery.

Minimal information for studies of extracellular vesicles (MISEV2023): From basic to advanced approaches

Extracellular vesicles (EVs), through their complex cargo, can reflect the state of their cell of origin and change the functions and phenotypes of other cells. These features indicate strong biomarker and therapeutic potential and have generated broad interest, as evidenced by the steady year-on-year increase in the numbers of scientific publications about EVs. Important advances have been made in EV metrology and in understanding and applying EV biology. However, hurdles remain to realising the potential of EVs in domains ranging from basic biology to clinical applications due to challenges in EV nomenclature, separation from non-vesicular extracellular particles, characterisation and functional studies. To address the challenges and opportunities in this rapidly evolving field, the International Society for Extracellular Vesicles (ISEV) updates its 'Minimal Information for Studies of Extracellular Vesicles', which was first published in 2014 and then in 2018 as MISEV2014 and MISEV2018, respectively. The goal of the current document, MISEV2023, is to provide researchers with an updated snapshot of available approaches and their advantages and limitations for production, separation and characterisation of EVs from multiple sources, including cell culture, body fluids and solid tissues. In addition to presenting the latest state of the art in basic principles of EV research, this document also covers advanced techniques and approaches that are currently expanding the boundaries of the field. MISEV2023 also includes new sections on EV release and uptake and a brief discussion of in vivo approaches to study EVs. Compiling feedback from ISEV expert task forces and more than 1000 researchers, this document conveys the current state of EV research to facilitate robust scientific discoveries and move the field forward even more rapidly.

Comparison of cow's milk allergy models highlighted higher humoral and Th2 immune responses in BALB/c than C3H/HeNCrl mice

Cow's milk allergy (CMA) is common in early childhood and the incidence is increasing. However, its mechanisms of action are still not fully understood due to the range of different clinical symptoms. So far, the development of different mouse models has been the best choice to study the molecular mechanisms triggering allergy. However, the selection of suitable strains for the establishment of animal models truly representative of associated human pathologies is still a challenge. Hence, we focused on both C3H/HeNCrl and BALB/c mice to characterize their susceptibility to CMA. After intraperitoneal sensitization, BALB/c and C3H/HeNCrl strains were challenged with β-lactoglobulin (BLG), and compared in allergic symptoms and active immune response, which assessed by specific antibody production and cytokine release. At first, both groups exhibited anaphylaxis, showed specific BLG-related IgE, Th2 response and seemed both suitable for the development of CMA models. However, a detailed analysis revealed that BALB/c had both stronger humoral and Th2 immune responses, producing more antibodies (IgE and IgG/IgG1/IgG2a), and releasing higher levels of Th2-associated cytokines (IL-4, IL-5, IL-13) compared to C3H/HeNCrl mice. Therefore, BALB/c strain would represent a preferential choice in the establishment of CMA models. This study highlights the subtle differences and major outcomes in the selection of mouse strains for the development of suitable food allergy models.

Milk exosomes anchored with hydrophilic and zwitterionic motifs enhance mucus permeability for applications in oral gene delivery

Exosomes have emerged as a promising tool for the delivery of drugs and genetic materials, owing to their biocompatibility and non-immunogenic nature. However, challenges persist in achieving successful oral delivery due to their susceptibility to degradation in the harsh gastrointestinal (GI) environment and impeded transport across the mucus-epithelium barrier. To overcome these challenges, we have developed high-purity bovine milk exosomes (mExo) as a scalable and efficient oral drug delivery system, which can be customized by incorporating hydrophilic and zwitterionic motifs on their surface. In our study, we observed significantly improved transport rates by 2.5-4.5-fold in native porcine intestinal mucus after the introduction of hydrophilic and zwitterionic surface modifications, as demonstrated by transwell setup and fluorescence recovery after photobleaching (FRAP) analysis. Remarkably, mExo functionalized by a block peptide (BP), consisting of cationic and anionic amino acids arranged in blocks at the two ends, demonstrated superior tolerability in the acidic gastric environment (with a protein recovery rate of 84.8 ± 7.7%) and exhibited a 2.5-fold increase in uptake by intestinal epithelial cells. Furthermore, both mExo and mExo-BP demonstrated successful intracellular delivery of functional siRNA, resulting in up to 65% suppression of the target green fluorescence protein (GFP) gene expression at a low dose of siRNA (5 pmol) without causing significant toxicity. These findings highlight the immense potential of modifying mExo with hydrophilic and zwitterionic motifs for effective oral delivery of siRNA therapies.

Exploring the Hemostatic Effects of Platelet Lysate-Derived Vesicles: Insights from Mouse Models

Platelet transfusion has various challenges, and platelet-derived extracellular vesicles have been reported to have more significant procoagulant activity than platelets themselves. Furthermore, platelet products derived from platelet-rich plasma and platelet lysates (PLs) have gained attention for their physiological activity and potential role as drug delivery vehicles owing to the properties of their membranes. We aimed to investigate the characteristics of the fractions isolated through ultracentrifugation from mouse-washed PLs and assess the potential clinical applications of these fractions as a therapeutic approach for bleeding conditions. We prepared PLs from C57BL/6 mouse-washed platelets and isolated three different fractions (20K-vesicles, 100K-vesicles, and PLwo-vesicles) using ultracentrifugation. There was a notable difference in particle size distribution between 20K-vesicles and 100K-vesicles, particularly in terms of the most frequent diameter. The 20K-vesicles exhibited procoagulant activity with concentration dependence, whereas PLwo-vesicles exhibited anticoagulant activity. PLwo-vesicles did not exhibit thrombin generation capacity, and the addition of PLwo-vesicles to Microparticle Free Plasma extended the time to initiate thrombin generation by 20K-vesicles and decreased the peak thrombin value. In a tail-snip bleeding assay, pre-administration of 20K-vesicles significantly shortened bleeding time. PL-derived 20K-vesicles exhibited highly potent procoagulant activity, making them potential alternatives to platelet transfusion.

Extracellular vesicles and exosome-like nanovesicles as pioneering oral drug delivery systems

As extracellular vesicle (EV)-based nanotechnology has developed rapidly, it has made unprecedented opportunities for nanomedicine possible. EVs and exosome-like nanovesicles (ELNVs) are natural nanocarriers with unique structural, compositional, and morphological characteristics that provide excellent physical, chemical, and biochemical properties. In this literature, we examine the characteristics of EVs, including how they are administered orally and their therapeutic activity. According to the current examples of EVs and ELNVs for oral delivery, milk and plant EVs can exert therapeutic effects through their protein, nucleic acid, and lipid components. Furthermore, several methods for loading drugs into exosomes and targeting exosomes have been employed to investigate their therapeutic capability. Moreover, we discuss EVs as potential drug carriers and the potential role of ELNVs for disease prevention and treatment or as potential drug carriers in the future. In conclusion, the issues associated with the development of EVs and ELNVs from sources such as milk and plants, as well as concerns with standardized applications of these EVs, are discussed.

Homogenization and thermal processing reduce the concentration of extracellular vesicles in bovine milk

Extracellular vesicles (EVs) in bovine milk confer beneficial physiologic effects to consumers. Industrial processing treatments may affect the amount or bioactivity of EVs intrinsic to bovine milk. We investigated how the content and concentration of EVs were affected by homogenization and thermal processing of raw bovine milk. Raw milk was processed by homogenization, low-temperature (LT) heat, or pasteurization [high-temperature short-time (HTST) and ultra-high-temperature (UHT)] in a pilot processing facility. EVs were isolated from the raw and processed bovine milk using differential ultracentrifugation and quantified using a nanoparticle tracking analyzer. Bovine milk EVs were assessed for total miRNA and protein concentrations standardized to particle count using a fluorometric assay. There were 1.01 × 1010 (±3.30 × 109) EV particles per ml of bovine milk. All industrial processing treatments caused >60% decrease in EV concentration compared to the raw bovine milk. Homogenization and heat treatments independently and additively reduced the content of EVs in bovine milk. The averages of total miRNA/particle and total protein/particle concentrations were elevated threefold by low-temperature heat-processing treatment relative to HTST and UHT pasteurizations. The average diameter of EVs was reduced by 11%-16% by low temperature compared to raw milk (127 ± 13 nm). Homogenization and pasteurization indiscriminately reduce the EV concentration of bovine milk. Smaller EVs with higher protein content resist degradation when processing bovine milk at sub-pasteurization temperature. This new foundational knowledge may contribute to food product development on the preservation of EVs in processed dairy products, including bovine milk-based infant formulas that some newborns are dependent on for adequate growth and development.

Advances in separation and identification of biologically important milk proteins and peptides

Milk is a rich source of biologically important proteins and peptides. In addition, milk contains a variety of extracellular vesicles (EVs), including exosomes, that carry their own proteome cargo. EVs are essential for cell-cell communication and modulation of biological processes. They act as nature carriers of bioactive proteins/peptides in targeted delivery during various physiological and pathological conditions. Identification of the proteins and protein-derived peptides in milk and EVs and recognition of their biological activities and functions had a tremendous impact on food industry, medicine research, and clinical applications. Advanced separation methods, mass spectrometry (MS)-based proteomic approaches and innovative biostatistical procedures allowed for characterization of milk protein isoforms, genetic/splice variants, posttranslational modifications and their key roles, and contributed to novel discoveries. This review article discusses recently published developments in separation and identification of bioactive proteins/peptides from milk and milk EVs, including MS-based proteomic approaches.

Potential therapeutic effects of milk-derived exosomes on intestinal diseases

Exosomes are extracellular vesicles with the diameter of 30 ~ 150 nm, and are widely involved in intercellular communication, disease diagnosis and drug delivery carriers for targeted disease therapy. Therapeutic application of exosomes as drug carriers is limited due to the lack of sources and methods for obtaining adequate exosomes. Milk contains abundant exosomes, several studies have shown that milk-derived exosomes play crucial roles in preventing and treating intestinal diseases. In this review, we summarized the biogenesis, secretion and structure, current novel methods used for the extraction and identification of exosomes, as well as discussed the role of milk-derived exosomes in treating intestinal diseases, such as inflammatory bowel disease, necrotizing enterocolitis, colorectal cancer, and intestinal ischemia and reperfusion injury by regulating intestinal immune homeostasis, restoring gut microbiota composition and improving intestinal structure and integrity, alleviating conditions such as oxidative stress, cell apoptosis and inflammation, and reducing mitochondrial reactive oxygen species (ROS) and lysosome accumulation in both humans and animals. In addition, we discussed future prospects for the standardization of milk exosome production platform to obtain higher concentration and purity, and complete exosomes derived from milk. Several in vivo clinical studies are needed to establish milk-derived exosomes as an effective and efficient drug delivery system, and promote its application in the treatment of various diseases in both humans and animals.

Extracellular Vesicles for Drug Delivery in Cancer Treatment

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

Application of Milk Exosomes for Musculoskeletal Health: Talking Points in Recent Outcomes

Milk is a nutrient-rich food source, and among the various milks, breast milk is a nutrient source provided by mothers to newborns in many mammals. Exosomes are nano-sized membranous extracellular vesicles that play important roles in cell-to-cell communication. Exosomes originate from endogenous synthesis and dietary sources such as milk. Discovered through electron microscopy as floating vesicles, the existence of exosomes in human milk was confirmed owing to a density between 1.10 and 1.18 g/mL in a sucrose gradient corresponding to the known density of exosomes and detection of MHC classes I and II, CD63, CD81, and CD86 on the vesicles. To date, milk exosomes have been used for treating many diseases, including cancers, and are widely proposed as promising carriers for the delivery of chemotherapeutic agents. However, few studies on milk exosomes focus on geriatric health, especially sarcopenia and osteoporosis related to bone and muscle. Therefore, the present study focused on milk exosomes and their cargoes, which are potential candidates for dietary supplements, and when combined with drugs, they can be effective in treating musculoskeletal diseases. In this review, we introduce the basic concepts, including the definition, various sources, and cargoes of milk exosomes, and exosome isolation and characterization methods. Additionally, we review recent literature on the musculoskeletal system and milk exosomes. Since inflammation and oxidative stress underly musculoskeletal disorders, studies reporting the antioxidant and anti-inflammatory properties of milk exosomes are also summarized. Finally, the therapeutic potential of milk exosomes in targeting muscle and bone health is proposed.

A Combined Western and Bead-Based Multiplex Platform to Characterize Extracellular Vesicles

In regenerative medicine, extracellular vesicles (EVs) are considered as a promising cell-free approach. EVs are lipid bilayer-enclosed vesicles secreted by cells and are key players in intercellular communication. EV-based therapeutic approaches have unique advantages over the use of cell-based therapies, such as a high biological, but low immunogenic and tumorigenic potential. To analyze the purity and biochemical composition of EV preparations, the International Society for Extracellular Vesicles (ISEV) has prepared guidelines recommending the analysis of multiple (EV) markers, as well as proteins coisolated/recovered with EVs. Traditional methods for EV characterization, such as Western blotting, require a relatively high EV sample/protein input for the analysis of one protein. We here evaluate a combined Western and bead-based multiplex platform, called DigiWest, for its ability to detect simultaneously multiple EV markers in an EV-containing sample with inherent low protein input. DigiWest analysis was performed on EVs from various sources and species, including mesenchymal stromal cells, notochordal cells, and milk, from human, pig, and dog. The study established a panel of nine antibodies that can be used as cross-species for the detection of general EV markers and coisolates in accordance with the ISEV guidelines. This optimized panel facilitates the parallel evaluation of EV-containing samples, allowing for a comprehensive characterization and assessment of their purity. The total protein input for marker analysis with DigiWest was 1 μg for all nine antibodies, compared with ∼10 μg protein input required for traditional Western blotting for one antibody. These findings demonstrate the potential of the DigiWest technique for characterizing various types of EVs in the regenerative medicine field.

Isolation and Characterization of Cow-, Buffalo-, Sheep- and Goat-Milk-Derived Extracellular Vesicles

Milk is a complex biological fluid that has high-quality proteins including growth factors and also contains extracellular vesicles (EVs). EVs are a lipid bilayer containing vesicles that contain proteins, metabolites and nucleic acids. Several studies have proposed that EVs in cow milk can survive the gut and can illicit cross-species communication in the consuming host organism. In this study, we isolated and characterized extracellular vesicles from the raw milk of the four species of the Bovidae family, namely cow, sheep, goat and buffalo, that contribute 99% of the total milk consumed globally. A comparative proteomic analysis of these vesicles was performed to pinpoint their potential functional role in health and disease. Vesicles sourced from buffalo and cow milk were particularly enriched with proteins implicated in modulating the immune system. Furthermore, functional studies were performed to determine the anti-cancer effects of these vesicles. The data obtained revealed that buffalo-milk-derived EVs induced significantly higher cell death in colon cancer cells. Overall, the results from this study highlight the potent immunoregulatory and anti-cancer nature of EVs derived from the milk of Bovidae family members.

Isolation of goat milk small extracellular vesicles by novel combined bio-physical methodology

Introduction: Goat milk is notable as a cost-effective source of exosomes, also known as small extracellular vesicles (sEVs). These nanoparticle-like structures are naturally secreted by cells and have emerged as potential diagnostic agents and drug delivery systems, also supported by their proven therapeutic effects. However, the complexity of goat milk and the lack of standardized protocols make it difficult to isolate pure sEVs. This work presents an optimized approach that combines well-established physical isolation methods with the biological treatment of milk with rennet. Methods: sEVs derived from goat milk were purified using a methodology that combines differential ultracentrifugation, rennet, and size-exclusion chromatography. This novel strategy was compared with two of the main methodologies developed for isolating extracellular vesicles from bovine and human milk by means of physico-chemical characterization of collected vesicles using Transmission Electron Microscopy, Western blot, Bradford Coomassie assay, Dynamic Light Scattering, Nanoparticle Tracking Analysis and Zeta Potential. Results: Vesicles isolated with the optimized protocol had sEV-like characteristics and high homogeneity, while samples obtained with the previous methods were highly aggregated, with significant residual protein content. Discussion: This work provides a novel biophysical methodology for isolating highly enriched goat milk sEVs samples with high stability and homogeneity, for their further evaluation in biomedical applications as diagnostic tools or drug delivery systems.

Plant and mammalian-derived extracellular vesicles: a new therapeutic approach for the future

Background: In recent years, extracellular vesicles have been recognized as important mediators of intercellular communication through the transfer of active biomolecules (proteins, lipids, and nucleic acids) across the plant and animal kingdoms and have considerable roles in several physiological and pathological mechanisms, showing great promise as new therapeutic strategies for a variety of pathologies. Methods: In this study, we carefully reviewed the numerous articles published over the last few decades on the general knowledge of extracellular vesicles, their application in the therapy of various pathologies, and their prospects as an approach for the future. Results: The recent discovery and characterization of extracellular vesicles (EVs) of diverse origins and biogenesis have altered the current paradigm of intercellular communication, opening up new diagnostic and therapeutic perspectives. Research into these EVs released by plant and mammalian cells has revealed their involvement in a number of physiological and pathological mechanisms, such as embryonic development, immune response, tissue regeneration, and cancer. They are also being studied as potential biomarkers for disease diagnosis and vectors for drug delivery. Conclusion: Nanovesicles represent powerful tools for intercellular communication and the transfer of bioactive molecules. Their molecular composition and functions can vary according to their origin (plant and mammalian), so their formation, composition, and biological roles open the way to therapeutic applications in a variety of pathologies, which is arousing growing interest in the scientific community. Clinical Trial Registration: ClinicalTrials.gov identifier: NCT03608631.

Bovine milk-derived extracellular vesicles enhance doxorubicin sensitivity in triple negative breast cancer cells by targeting metabolism and STAT signalling

Metastatic triple-negative breast cancer (TNBC) has a low 5-year survival rate of below 30% with systemic chemotherapy being the most widely used treatment. Bovine milk-derived extracellular vesicles (MEVs) have been previously demonstrated to have anti-cancer attributes. In this study, we isolated bovine MEVs from commercial milk and characterised them according to MISEV guidelines. Bovine MEVs sensitised TNBC cells to doxorubicin, resulting in reduced metabolic potential and cell-viability. Label-free quantitative proteomics of cells treated with MEVs and/or doxorubicin suggested that combinatorial treatment depleted various pro-tumorigenic interferon-inducible gene products and proteins with metabolic function, previously identified as therapeutic targets in TNBC. Combinatorial treatment also led to reduced abundance of various STAT proteins and their downstream oncogenic targets with roles in cell-cycle and apoptosis. Taken together, this study highlights the ability of bovine MEVs to sensitise TNBC cells to standard-of-care therapeutic drug doxorubicin, paving the way for novel treatment regimens.

Delivery of mitochondria-containing extracellular vesicles to the BBB for ischemic stroke therapy

INTRODUCTION

Ischemic stroke-induced mitochondrial dysfunction in brain endothelial cells (BECs) leads to breakdown of the blood-brain barrier (BBB) causing long-term neurological dysfunction. Restoration of mitochondrial function in injured BECs is a promising therapeutic strategy to alleviate stroke-induced damage. Mounting evidence demonstrate that selected subsets of cell-derived extracellular vehicles (EVs), such as exosomes (EXOs) and microvesicles (MVs), contain functional mitochondrial components. Therefore, development of BEC-derived mitochondria-containing EVs for delivery to the BBB will (1) alleviate mitochondrial dysfunction and limit long-term neurological dysfunction in ischemic stroke and (2) provide an alternative therapeutic option for treating numerous other diseases associated with mitochondrial dysfunction.

AREA COVERED

This review will discuss (1) how EV subsets package different types of mitochondrial components during their biogenesis, (2) mechanisms of EV internalization and functional mitochondrial responses in the recipient cells, and (3) EV biodistribution and pharmacokinetics - key factors involved in the development of mitochondria-containing EVs as a novel BBB-targeted stroke therapy.

EXPERT OPINION

Mitochondria-containing MVs have demonstrated therapeutic benefits in ischemic stroke and other pathologies associated with mitochondrial dysfunction. Delivery of MV mitochondria to the BBB is expected to protect the BBB integrity and neurovascular unit post-stroke. MV mitochondria quality control, characterization, mechanistic understanding of its effects in vivo, safety and efficacy in different preclinical models, large-scale production, and establishment of regulatory guidelines are foreseeable milestones to harness the clinical potential of MV mitochondria delivery.

Exosomes as an Emerging Plasmid Delivery Vehicle for Gene Therapy

Despite its introduction more than three decades ago, gene therapy has fallen short of its expected potential for the treatment of a broad spectrum of diseases and continues to lack widespread clinical use. The fundamental limitation in clinical translatability of this therapeutic modality has always been an effective delivery system that circumvents degradation of the therapeutic nucleic acids, ensuring they reach the intended disease target. Plasmid DNA (pDNA) for the purpose of introducing exogenous genes presents an additional challenge due to its size and potential immunogenicity. Current pDNA methods include naked pDNA accompanied by electroporation or ultrasound, liposomes, other nanoparticles, and cell-penetrating peptides, to name a few. While the topic of numerous reviews, each of these methods has its own unique set of limitations, side effects, and efficacy concerns. In this review, we highlight emerging uses of exosomes for the delivery of pDNA for gene therapy. We specifically focus on bovine milk and colostrum-derived exosomes as a nano-delivery "platform". Milk/colostrum represents an abundant, scalable, and cost-effective natural source of exosomes that can be loaded with nucleic acids for targeted delivery to a variety of tissue types in the body. These nanoparticles can be functionalized and loaded with pDNA for the exogenous expression of genes to target a wide variety of disease phenotypes, overcoming many of the limitations of current gene therapy delivery techniques.

Treatment of Cardiac Fibrosis with Extracellular Vesicles: What Is Missing for Clinical Translation?

Heart failure is the leading cause of morbidity and mortality and currently affects more than 60 million people worldwide. A key feature in the pathogenesis of almost all forms of heart failure is cardiac fibrosis, which is characterized by excessive accumulation of extracellular matrix components in the heart. Although cardiac fibrosis is beneficial in the short term after acute myocardial injury to preserve the structural and functional integrity of the heart, persistent cardiac fibrosis contributes to pathological cardiac remodeling, leading to mechanical and electrical dysfunction of the heart. Despite its high prevalence, standard therapies specifically targeting cardiac fibrosis are not yet available. Cell-based approaches have been extensively studied as potential treatments for cardiac fibrosis, but several challenges have been identified during clinical translation. The observation that extracellular vesicles (EVs) derived from stem and progenitor cells exhibit some of the therapeutic effects of the parent cells has paved the way to overcome limitations associated with cell therapy. However, to make EV-based products a reality, standardized methods for EV production, isolation, characterization, and storage must be established, along with concrete evidence of their safety and efficacy in clinical trials. This article discusses EVs as novel therapeutics for cardiac fibrosis from a translational perspective.

Circadian Rhythm Does Not Affect the miRNA Cargo of Bovine Raw Milk Extracellular Vesicles

Extracellular vesicles (EVs) and their microRNA (miRNA) cargo have been proposed as possible mammary gland health biomarkers in cattle. However, throughout the day, the biologically active milk components, such as miRNAs, may change due to the dynamic nature of milk. The current study aimed to evaluate the circadian fluctuation of milk EVs miRNA cargo to assess the feasibility of milk EVs as future biomarkers for mammary gland health management. Milk from four healthy dairy cows was collected for four consecutive days in the two daily milking sessions in the morning and the evening. The isolated EVs were heterogeneous, intact, and carried the EV protein markers CD9, CD81, and TSG101, as shown by transmission electron microscopy and western blot. The miRNA sequencing results demonstrate that the abundance of miRNA cargo in milk EVs remained stable, unlike other milk components, such as somatic cells, that changed during milking sessions. These findings indicated that the miRNA cargo within milk EVs remains stable irrespective of the time of day, suggesting their potential utility as diagnostic markers for mammary gland health.

Goat milk extracellular vesicles: immuno-modulation effects on porcine monocyte-derived macrophages in vitro

Introduction

Extracellular vesicles (EVs) are nanometric-membrane-bound sub-cellular structures, which can be recovered from milk. Milk EVs have drawn increasing interest due to their potential biomedical applications, therefore it is important to investigate their impact on key immune cells, such as macrophages.

Methods

In this work, the immunomodulatory effects of goat milk EVs on untreated (moMФ) and classically activated (moM1) porcine monocyte-derived macrophages were investigated using flow cytometry, ELISA, and gene expression assays.

Results

These particles were efficiently internalized by macrophages and high doses (60 mg protein weight) triggered the upregulation of MHC I and MHC II DR on moMФ, but not on moM1. In moMФ, exposure to low doses (0.6 mg) of mEVs enhanced the gene expression of IL10, EBI3, and IFNB, whereas high doses up-regulated several pro-inflammatory cytokines. These nanosized structures slightly modulated cytokine gene expression on moM1. Accordingly, the cytokine (protein) contents in culture supernatants of moMФ were mildly affected by exposure to low doses of mEVs, whereas high doses promoted the increased release of TNF, IL-8, IL-1a, IL-1b, IL-1Ra, IL-6, IL-10, and IL-12. The cytokines content in moM1 supernatants was not critically affected.

Discussion

Overall, our data support a clinical application of these molecules: they polarized macrophages toward an M1-like phenotype, but this activation seemed to be controlled, to prevent potentially pathological over-reaction to stressors.

Milk Exosomes: Next-Generation Agents for Delivery of Anticancer Drugs and Therapeutic Nucleic Acids

Exosomes are nanovesicles 40-120 nm in diameter secreted by almost all cell types and providing humoral intercellular interactions. Given the natural origin and high biocompatibility, the potential for loading various anticancer molecules and therapeutic nucleic acids inside, and the surface modification possibility for targeted delivery, exosomes are considered to be a promising means of delivery to cell cultures and experimental animal organisms. Milk is a unique natural source of exosomes available in semi-preparative and preparative quantities. Milk exosomes are highly resistant to the harsh conditions of the gastrointestinal tract. In vitro studies have demonstrated that milk exosomes have an affinity to epithelial cells, are digested by cells by endocytosis mechanism, and can be used for oral delivery. With milk exosome membranes containing hydrophilic and hydrophobic components, exosomes can be loaded with hydrophilic and lipophilic drugs. This review covers a number of scalable protocols for isolating and purifying exosomes from human, cow, and horse milk. Additionally, it considers passive and active methods for drug loading into exosomes, as well as methods for modifying and functionalizing the surface of milk exosomes with specific molecules for more efficient and specific delivery to target cells. In addition, the review considers various approaches to visualize exosomes and determine cellular localization and bio-distribution of loaded drug molecules in tissues. In conclusion, we outline new challenges for studying milk exosomes, a new generation of targeted delivery agents.

Multifunctional Milk-Derived Small Extracellular Vesicles and Their Biomedical Applications

In recent years, small extracellular vesicles (sEVs) have been regarded as the next generation of novel delivery systems after lipid nanoparticles because of their advantages and huge prospects in drug delivery. Studies have shown that sEVs are abundant in milk and therefore can be a large and economical source of sEVs. Natural milk-derived small extracellular vesicles (msEVs) have important functions such as immune regulation, anti-bacterial infection, anti-oxidative, etc., and play a beneficial role in human health at multiple levels, including intestinal health, bone/muscle metabolism, and microbiota regulation. In addition, because they can pass the gastrointestinal barrier and have low immunogenicity, good biocompatibility, and stability, msEVs are considered a crucial oral drug delivery vehicle. Moreover, msEVs can be further engineered for targeted delivery to prolong the circulation time or enhance local drug concentrations. However, msEVs separation and purification, complex contents, and quality control hinder their application in drug delivery. This paper provides a comprehensive review of the biogenesis and characteristics, isolation and purification, composition, loading methods, and function of msEVs, based on which their applications in biomedical fields are further explored.

Modification of Extracellular Vesicle Surfaces: An Approach for Targeted Drug Delivery

Extracellular vesicles (EVs) are a promising drug delivery vehicle candidate because of their natural origin and intrinsic function of transporting various molecules between different cells. Several advantages of the EV delivery platform include enhanced permeability and retention effect, efficient interaction with recipient cells, the ability to traverse biological barriers, high biocompatibility, high biodegradability, and low immunogenicity. Furthermore, EV membranes share approximately similar structures and contents to the cell membrane, which allows surface modification of EVs, an approach to enable specific targeting. Enhanced drug accumulation in intended sites and reduced adverse effects of chemotherapeutic drugs are the most prominent effects of targeted drug delivery. In order to improve the targeting ability of EVs, chemical modification and genetic engineering are the most adopted methods to date. Diverse chemical methods are employed to decorate EV surfaces with various ligands such as aptamers, carbohydrates, peptides, vitamins, and antibodies. In this review, we introduce the biogenesis, content, and cellular pathway of natural EVs and further discuss the genetic modification of EVs, and its challenges. Furthermore, we provide a comprehensive deliberation on the various chemical modification methods for improved drug delivery, which are directly related to increasing the therapeutic index.

Niacin/β-hydroxybutyrate regulates milk fat and milk protein synthesis via the GPR109A/Gi/mTORC1 pathway

As a crucial receptor of BHBA and niacin, GPR109A is largely expressed in the mammary gland. However, the role of GPR109A in milk synthesis and its underlying mechanism is still largely unknown. In this study, we first investigated the effect of GPR109A agonists (niacin/BHBA) on milk fat and milk protein synthesis in a mouse mammary epithelial cell line (HC11) and PMECs (porcine mammary epithelial cells). The results showed that both niacin and BHBA promote milk fat and milk protein synthesis with the activation of mTORC1 signaling. Importantly, knockdown GPR109A attenuated the niacin-induced increase of milk fat and protein synthesis and the niacin-induced activation of mTORC1 signaling. Furthermore, we found that GPR109A downstream G protein-G_αi and -G_βγ participated in the regulation of milk synthesis and the activation of mTORC1 signaling. Consistent with the finding in vitro, dietary supplementation with niacin increases milk fat and protein synthesis in mice with the activation of GPR109A-mTORC1 signaling. Collectively, GPR109A agonists promote the synthesis of milk fat and milk protein through the GPR109A/G_i/mTORC1 signaling pathway.

Intraduodenal Delivery of Exosome-Loaded SARS-CoV-2 RBD mRNA Induces a Neutralizing Antibody Response in Mice

Severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2), which causes coronavirus disease 2019 (COVID-19), has presented numerous challenges to global health. Vaccines, including lipid—based nanoparticle mRNA, inactivated virus, and recombined protein, have been used to prevent SARS-CoV-2 infections in clinics and have been immensely helpful in controlling the pandemic. Here, we present and assess an oral mRNA vaccine based on bovine-milk-derived exosomes (milk-exos), which encodes the SARS-CoV-2 receptor-binding domain (RBD) as an immunogen. The results indicate that RBD mRNA delivered by milk-derived exosomes can produce secreted RBD peptides in 293 cells in vitro and stimulates neutralizing antibodies against RBD in mice. These results indicate that SARS-CoV-2 RBD mRNA vaccine loading with bovine-milk-derived exosomes is an easy, cheap, and novel way to introduce immunity against SARS-CoV-2 in vivo. Additionally, it also can work as a new oral delivery system for mRNA.

Placental Extracellular Vesicles Can Be Loaded with Plasmid DNA

Recently, extracellular vesicles (EVs) have garnered considerable interest as potential vehicles for drug delivery, including gene therapy. Although EVs from diverse sources have been investigated, current techniques used in the field for EV generation limit large-scale EV production. The placenta is essentially a tissue transplant and has unique properties that allow it to avoid the maternal immune system making it likely that placental EVs will not generate inflammatory responses and will avoid clearance by the immune system. We propose that placental EVs produced from explant cultures are an efficient method to produce considerable quantities of EVs that would be safe to administer, and we hypothesize that placental EVs can be loaded with large exogenous plasmids. To this end, we trialed three strategies to load plasmid DNA into placental EVs, including loading via electroporation of placental tissue prior to EV isolation and loading directly into placental EVs via electroporation or direct incubation of the EVs in plasmid solution. We report that the placenta releases vast quantities of EVs compared to placental cells in monolayer cultures. We show successful loading of plasmid DNA into both large- and small-EVs following both exogenous loading strategies with more plasmid encapsulated in large-EVs. Importantly, direct incubation did not alter EV size nor quantity. Further, we showed that the loading efficiency into EVs was dependent on the exogenous plasmid DNA dose and the DNA size. These results provide realistic estimates of plasmid loading capacity into placental EVs using current technologies and showcase the potential of placental EVs as DNA delivery vehicles.

High-Yield Production of Extracellular Vesicle Subpopulations with Constant Quality Using Batch-Refeed Cultures

The conventional manufacturing of extracellular vesicles (EVs) is characterized by low yields and batch-to-batch variability, hampering fundamental research on EVs and their practical applications. Perfusion operations have huge potential to address these limitations and increase the productivity and quality of EVs. In this study, perfusion cultures are simulated with batch-refeed systems and their productivity is compared with that achieved using batch cultures. It is shown that a shift from batch to batch-refeed system can increase the space-time yields of a target EV subpopulation characterized by CD81 and CD63 biomarkers by threefold. Moreover, it is demonstrated that the method facilitates the consistent production of the target EVs from cells maintained under constant conditions for 13 days. These results indicate that the use of perfusion cultures is a promising strategy to increase the manufacturing yield of EVs and control the production of specific EV subpopulations with constant quality attributes, thereby improving reproducibility.

Milk-Derived Exosomes as a Promising Vehicle for Oral Delivery of Hydrophilic Biomacromolecule Drugs

Exosomes, as promising vehicles, have been widely used in the research of oral drug delivery, but the generally low drug loading efficiency of exosomes seriously limits its application and transformation. In this study, we systematically investigated the effects of drug loading methods and physicochemical properties (lipophilicity and molecular weight) on drug loading efficiency of milk-derived exosomes to explore the most appropriate loading conditions. Our finding revealed that the drug loading efficiency of exosomes was closely related to the drug loading method, drug lipophilicity, drug molecular weight and exosome/drug proportions. Of note, we demonstrated the universality that hydrophilic biomacromolecule drugs were the most appropriate loading drugs for milk-derived exosomes, which was attributed to the efficient loading capacity and sustained release behavior. Furthermore, milk-derived exosomes could significantly improve the transepithelial transport and oral bioavailability of model hydrophilic biomacromolecule drugs (octreotide, exendin-4 and salmon calcitonin). Collectively, our results suggested that the encapsulation of hydrophilic biomacromolecule drugs might be the most promising direction for milk exosomes as oral drug delivery vehicles.

Alternative biological sources for extracellular vesicles production and purification strategies for process scale-up

Extracellular vesicles (EVs) are phospholipidic bi-layer enclosed nanoparticles secreted naturally by all cell types. They are attracting increasing attention in the fields of nanomedicine, nutraceutics and cosmetics as biocompatible carriers for drug delivery, with intrinsic properties beneficial to human health. Scientific work now focuses on developing techniques for isolating EVs that can translate into industrial-scale production and meet rigorous clinical requirements. The science of EVs is ongoing, and many pitfalls must be addressed, such as the requirement for standard, reproducible, inexpensive, and Good Manufacturing Practices (GMP) adherent EV processing techniques. Researchers are exploring the use of alternative sources to EVs derived from mammalian cultures, such as plant EVs, as well as the use of bacteria, algae and milk. Regarding the downstream processing of EVs, many alternative techniques to the ultracentrifugation (UC) protocols most commonly used in the laboratory are emerging. In the context of process scale-up, membrane-based processes for isolation and purification of EVs are the most promising, either as stand-alone processes or in combination with chromatographic techniques. This review discusses current trends on EVs source selection and EVs downstream processing techniques, with a focus on plant-derived EVs and membrane-based techniques for EVs enrichment.

Milk exosomes: an oral drug delivery system with great application potential

Exosomes are extracellular vesicles with the smallest diameter, usually divided into cellular sources and body fluid sources. Due to their special properties different from cell-derived exosomes, the application of milk exosomes as an oral drug delivery system has increased greatly. This article introduces the physical and chemical properties of exosomes, separation technology, dyeing and labeling technology, targeted modification technology, and the application of milk exosomes in drug loading and disease therapies.

Antioxidants encapsulated milk-derived exosomes for functional food development

Reactive oxygen species are known to be involved in various diseases, and antioxidant ingredients are expected to essentially prevent diseases and contribute to improving health. However, antioxidants are easily degraded by enzymes before being absorbed in the intestine, so a means of transport that prevents their degradation in the body is necessary. Exosomes, which play an important role in communication between individual cells, have attracted attention as a new transport carrier of miRNA and DNA, but not yet fully exploited in food research. More recently, exosomes extracted from bovine milk began to be widely used as a cost-effective transport carrier not in clinical medicine but also in functional food materials. To develop practical applications as carriers for functional foods, systematic studies are necessary to clarify the introduction efficiency and the properties of encapsulated substances. In this study, we applied electroporation and incubation to encapsulate antioxidants into the exosomes and studied the encapsulation efficiency into the exosomes and the anticancer activity.

Oral Administration of Bovine Milk-Derived Extracellular Vesicles Attenuates Cartilage Degeneration via Modulating Gut Microbiota in DMM-Induced Mice

Osteoarthritis (OA) is the most common joint disease primarily characterized by cartilage degeneration. Milk-derived extracellular vesicles (mEVs) were reported to inhibit catabolic and inflammatory processes in the cartilage of OA patients. However, the current therapies target the advanced symptoms of OA, and it is significant to develop a novel strategy to inhibit the processes driving OA pathology. In this study, we investigated the therapeutic potential of mEVs in alleviating OA in vivo. The results revealed that mEVs ameliorated cartilage degeneration by increasing hyaline cartilage thickness, decreasing histological Osteoarthritis Research Society International (OARSI) scores, enhancing matrix synthesis, and reducing the expression of cartilage destructive enzymes in the destabilization of medial meniscus (DMM) mice. In addition, the disturbed gut microbiota in DMM mice was partially improved upon treatment with mEVs. It was observed that the pro-inflammatory bacteria (Proteobacteria) were reduced and the potential beneficial bacteria (Firmicutes, Ruminococcaceae, Akkermansiaceae) were increased. mEVs could alleviate the progression of OA by restoring matrix homeostasis and reshaping the gut microbiota. These findings suggested that mEVs might be a potential therapeutic dietary supplement for the treatment of OA.

Oral delivery of nucleic acid therapeutics: Challenges, strategies, and opportunities

In recent decades, advances in chemical synthesis and delivery systems have accelerated the development of therapeutic nucleic acids, several of which have been approved by the Us Food and Drug Administration (FDA). Oral nucleic acid delivery is preferred because of its simplicity and patient compliance, but it still presents distinct challenges. The negative charge, hydrophilicity, and large molecular weight of nucleic acids combined with in vivo gastrointestinal (GI) barriers (e.g., acidic pH, enzymes, mucus, and intestinal epithelial cells) severely hinder their delivery efficacy. Recently, various nanoparticles (NPs), ranging from polymeric to lipid-based (L)NPs and extracellular vesicles (EVs), have been extensively explored to address these obstacles. In this review, we describe the physiological barriers in the GI tract and summarize recent advances in NP-based oral nucleic acid therapeutics.

The emerging role of exosomes in innate immunity, diagnosis and therapy

Exosomes, which are nano-sized transport bio-vehicles, play a pivotal role in maintaining homeostasis by exchanging genetic or metabolic information between different cells. Exosomes can also play a vital role in transferring virulent factors between the host and parasite, thereby regulating host gene expression and the immune interphase. The association of inflammation with disease development and the potential of exosomes to enhance or mitigate inflammatory pathways support the notion that exosomes have the potential to alter the course of a disease. Clinical trials exploring the role of exosomes in cancer, osteoporosis, and renal, neurological, and pulmonary disorders are currently underway. Notably, the information available on the signatory efficacy of exosomes in immune-related disorders remains elusive and sporadic. In this review, we discuss immune cell-derived exosomes and their application in immunotherapy, including those against autoimmune connective tissue diseases. Further, we have elucidated our views on the major issues in immune-related pathophysiological processes. Therefore, the information presented in this review highlights the role of exosomes as promising strategies and clinical tools for immune regulation.

Updated Methods of Extracellular Vesicles Isolation

Extracellular vesicles (EVs) are considered as cargo and mediate intercellular communication. As natural biological nanoparticles, EVs can be secreted by almost all kinds of cells and exist in biofluids such as milk, urine, blood, etc. In the past decades, several methods have been utilized to isolate EVs from cell culture medium, biofluids, and tissues. Here in this chapter, we summarized conventional and novel methods and fundamental procedures of EVs extraction and purification from different biofluids (plasma, urine, milk, and saliva) and tissues (brain, intestinal tissue, muscles, and heart). The present section also discusses how to choose appropriate methods to extract EVs from tissues based on downstream analysis. This chapter will expand the horizons of EVs isolation and purification from different mediums.

Comparative Proteomic Analysis of Milk-Derived Extracellular Vesicles from Dairy Cows with Clinical and Subclinical Mastitis

Extracellular vesicles (EVs) are membranous vesicles found in biological fluids with essential functions. However, milk-derived EV proteins from clinical mastitis (CM) and subclinical mastitis (SM) cows have yet to be studied in detail. In this study, milk-derived EVs of CM, SM, and Healthy cows were extracted using a combination of acetic acid/ultracentrifugation and density gradient ultracentrifugation and analyzed using a shotgun proteomic by data-independent acquisition mode. A total of 1253 milk exosome proteins were identified and quantified. Differently enriched (DE) proteins were identified as given a Benjamini−Hochberg adjusted p < 0.05 and a fold change of at least 2. There were 53 and 1 DE proteins in milk-derived EVs from CM and SM cows compared with healthy cows. Protein S100-A9, Protein S100-A8, Chitinase-3-like protein 1, Haptoglobin, Integrin beta-2, and Chloride intracellular channel protein 1 were more abundant in the CM group (adjusted p < 0.05). Still, their enrichment in the SM group was not significant as in the Healthy group. The enrichment of DE proteins between CM and Healthy group was consistent with elevated GO (Gene Ontology) processes—defense response, defense response to Gram-positive bacterium, granulocyte chemotaxis also contributed to Reactome pathways—neutrophil degranulation, innate immune system, and antimicrobial peptides in the CM group. These results provide essential information on mastitis-associated proteins in milk-derived EVs and indicate the biological functions of milk-derived EVs proteins require further elucidation.

Cancer Therapy Empowered by Extracellular Vesicle-Mediated Targeted Delivery

Extracellular vesicles (EVs) are a class of nanoparticles that mediate signaling molecules delivery between donor and recipient cells. Heterogeneity in the content of EVs and their membrane surface proteins determines their unique targetability. Their low immunogenicity, capability to cross various biological barriers, and superior biocompatibility enable engineering-modified EVs to be ideal drug delivery carriers. In addition, the engineered EVs that emerge in recent years have become a powerful tool for cancer treatment through the selective delivery of bioactive molecules to therapeutic targets, such as tumor cells and stroma. Our review focuses on the various types of EV modifications and their promoting therapeutic capabilities, which provide an innovative means for cancer precision therapy.

Milk Exosomes Facilitate Oral Delivery of Drugs against Intestinal Bacterial Infections

Biopharmaceutics Classification System (BCS) class II and IV drugs exhibit low solubility and suffer a limitation in oral administration. Exosomes have attracted intensive attention in the efficient delivery of such compounds. However, low gastrointestinal stability and high production cost of exosomes hinder their development as drug carriers. Here, milk exosomes are functionalized with phosphatidylserine and are capable of improving the solubility of BCS class II and IV drugs, resulting in facilitating the oral delivery of the drugs. A natural flavonoid, α-mangostin, is loaded into exosomes (AExo) to enhance the antibacterial efficiency, demonstrated by clearing 99% of bacteria in macrophages. Furthermore, AExo exhibits high mucus penetrability and shows a significant therapeutic efficacy in two animal infection models. Collectively, this work expands the application of exosomes from bovine milk with simple operation and low cost, shedding light on the potential of milk exosomes in improving the solubility of drugs to enhance the efficacy of oral administration.