The therapeutic triad of extracellular vesicles: As drug targets, as drugs, and as drug carriers

Spinning with exosomes: electrospun nanofibers for efficient targeting of stem cell-derived exosomes in tissue regeneration

Electrospinning technique converts polymeric solutions into nanoscale fibers using an electric field and can be used for various biomedical and clinical applications. Extracellular vesicles (EVs) are cell-derived small lipid vesicles enriched with biological cargo (proteins and nucleic acids) potential therapeutic applications. In this review, we discuss extending the scope of electrospinning by incorporating stem cell-derived EVs, particularly exosomes, into nanofibers for their effective delivery to target tissues. The parameters used during the electrospinning of biopolymers limit the stability and functional properties of cellular products. However, with careful consideration of process requirements, these can significantly improve stability, leading to longevity, effectiveness, and sustained and localized release. Electrospun nanofibers are known to encapsulate or surface-adsorb biological payloads such as therapeutic EVs, proteins, enzymes, and nucleic acids. Small EVs, specifically exosomes, have recently attracted the attention of researchers working on regeneration and tissue engineering because of their broad distribution and enormous potential as therapeutic agents. This review focuses on current developments in nanofibers for delivering therapeutic cargo molecules, with a special emphasis on exosomes. It also suggests prospective approaches that can be adapted to safely combine these two nanoscale systems and exponentially enhance their benefits in tissue engineering, medical device coating, and drug delivery applications.

Genetically engineered loaded extracellular vesicles for drug delivery

The use of extracellular vesicles (EVs) for drug delivery is being widely explored by scientists from several research fields. To fully exploit their therapeutic potential, multiple methods for loading EVs have been developed. Although exogenous methods have been extensively utilized, in recent years the endogenous method has gained significant attention. This approach, based on parental cell genetic engineering, is suitable for loading large therapeutic biomolecules such as proteins and nucleic acids. We review the most commonly used EV loading methods and emphasize the inherent advantages of the endogenous method over the others. We also examine the most recent advances and applications of this innovative approach to inform on the diverse therapeutic opportunities that lie ahead in the field of EV-based therapies.

Biomimetic nanomaterials in myocardial infarction treatment: Harnessing bionic strategies for advanced therapeutics

Myocardial infarction (MI) and its associated poor prognosis pose significant risks to human health. Nanomaterials hold great potential for the treatment of MI due to their targeted and controlled release properties, particularly biomimetic nanomaterials. The utilization of biomimetic strategies based on extracellular vesicles (EVs) and cell membranes will serve as the guiding principle for the development of nanomaterial therapy in the future. In this review, we present an overview of research progress on various exosomes derived from mesenchymal stem cells, cardiomyocytes, or induced pluripotent stem cells in the context of myocardial infarction (MI) therapy. These exosomes, utilized as cell-free therapies, have demonstrated the ability to enhance the efficacy of reducing the size of the infarcted area and preventing ischaemic reperfusion through mechanisms such as oxidative stress reduction, polarization modulation, fibrosis inhibition, and angiogenesis promotion. Moreover, EVs can exert cardioprotective effects by encapsulating therapeutic agents and can be engineered to specifically target the infarcted myocardium. Furthermore, we discuss the use of cell membranes derived from erythrocytes, stem cells, immune cells and platelets to encapsulate nanomaterials. This approach allows the nanomaterials to camouflage themselves as endogenous substances targeting the region affected by MI, thereby minimizing toxicity and improving biocompatibility. In conclusion, biomimetic nano-delivery systems hold promise as a potentially beneficial technology for MI treatment. This review serves as a valuable reference for the application of biomimetic nanomaterials in MI therapy and aims to expedite the translation of NPs-based MI therapeutic strategies into practical clinical applications.

Emerging delivery systems based on aqueous two-phase systems: A review

The aqueous two-phase system (ATPS) is an all-aqueous system fabricated from two immiscible aqueous phases. It is spontaneously assembled through physical liquid-liquid phase separation (LLPS) and can create suitable templates like the multicompartment of the intracellular environment. Delicate structures containing multiple compartments make it possible to endow materials with advanced functions. Due to the properties of ATPSs, ATPS-based drug delivery systems exhibit excellent biocompatibility, extraordinary loading efficiency, and intelligently controlled content release, which are particularly advantageous for delivering drugs in vivo . Therefore, we will systematically review and evaluate ATPSs as an ideal drug delivery system. Based on the basic mechanisms and influencing factors in forming ATPSs, the transformation of ATPSs into valuable biomaterials is described. Afterward, we concentrate on the most recent cutting-edge research on ATPS-based delivery systems. Finally, the potential for further collaborations between ATPS-based drug-carrying biomaterials and disease diagnosis and treatment is also explored.

SIRT1 is a regulator of autophagy: Implications for the progression and treatment of myocardial ischemia-reperfusion

SIRT1 is a highly conserved nicotinamide adenine dinucleotide (NAD+)-dependent histone deacetylase. It is involved in the regulation of various pathophysiological processes, including cell proliferation, survival, differentiation, autophagy, and oxidative stress. Therapeutic activation of SIRT1 protects the heart and cardiomyocytes from pathology-related stress, particularly myocardial ischemia/reperfusion (I/R). Autophagy is an important metabolic pathway for cell survival during energy or nutrient deficiency, hypoxia, or oxidative stress. Autophagy is a double-edged sword in myocardial I/R injury. The activation of autophagy during the ischemic phase removes excess metabolic waste and helps ensure cardiomyocyte survival, whereas excessive autophagy during reperfusion depletes the cellular components and leads to autophagic cell death. Increasing research on I/R injury has indicated that SIRT1 is involved in the process of autophagy and regulates myocardial I/R. SIRT1 regulates autophagy through various pathways, such as the deacetylation of FOXOs, ATGs, and LC3. Recent studies have confirmed that SIRT1-mediated autophagy plays different roles at different stages of myocardial I/R injury. By targeting the mechanism of SIRT1-mediated autophagy at different stages of I/R injury, new small-molecule drugs, miRNA activators, or blockers can be developed. For example, resveratrol, sevoflurane, quercetin, and melatonin in the ischemic stage, coptisine, curcumin, berberine, and some miRNAs during reperfusion, were involved in regulating the SIRT1-autophagy axis, exerting a cardioprotective effect. Here, we summarize the possible mechanisms of autophagy regulation by SIRT1 in myocardial I/R injury and the related molecular drug applications to identify strategies for treating myocardial I/R injury.

Cancer-associated immune cells and their modulation by melatonin

OBJECTIVES

Rapidly growing evidence suggests that immune cells play a key role in determining tumor progression. Tumor cells are surrounded by a microenvironment composed of different cell populations including immune cells. The cross talk between tumor cells and the neighboring microenvironment is an important factor to take into account while designing tumor therapies. Despite significant advances in immunotherapy strategies, a relatively small proportion of patients have successfully responded to them. Therefore, the search for safe and efficient drugs, which could be used alongside conventional therapies to boost the immune system against tumors, is an ongoing need. In the present work, the modulatory effects of melatonin on different components of tumor immune microenvironment are reviewed.

METHODS

A thorough literature review was performed in PubMed, Scopus, and Web of Science databases. All published papers in English on tumor immune microenvironment and the relevant modulatory effects of melatonin were scrutinized.

RESULTS

Melatonin modulates macrophage polarization and prevents M2 induction. Moreover, it prevents the conversion of fibroblasts into cancer-associated fibroblasts (CAFs) and prevents cancer cell stemness. In addition, it can affect the payload composition of tumor-derived exosomes (TEXs) and their secretion levels to favor a more effective anti-tumor immune response. Melatonin is a safe molecule that affects almost all components of the tumor immune microenvironment and prevents them from being negatively affected by the tumor.

CONCLUSION

Based on the effects of melatonin on normal cells, tumor cells and microenvironment components, it could be an efficient compound to be used in combination with conventional immune-targeted therapies to increase their efficacy.

Inhibition of murine colorectal cancer metastasis by targeting M2-TAM through STAT3/NF-kB/AKT signaling using macrophage 1-derived extracellular vesicles loaded with oxaliplatin, retinoic acid, and Libidibia ferrea

Colorectal cancer is still unmanageable despite advances in target therapy. However, extracellular vesicles (EVs) have shown potential in nanomedicine as drug delivery systems, especially for modulating the immune cells in the tumor microenvironment (TME). In this study, M1 Macrophage EVs (M1EVs) were used as nanocarriers of oxaliplatin (M1EV1) associated with retinoic acid (M1EV2) and Libidibia ferrea (M1EV3), alone or in combination (M1EV4) to evaluate their antiproliferative and immunomodulatory potential on CT-26 and MC-38 colorectal cancer cell lines and prevent metastasis in mice of allograft and peritoneal colorectal cancer models. Tumors were evaluated by qRT-PCR and immunohistochemistry. The cell death profile and epithelial-mesenchymal transition process (EMT) were analyzed in vitro in colorectal cancer cell lines. Polarization of murine macrophages (RAW264.7 cells) was also carried out. M1EV2 and M1EV3 used alone or particularly M1EV4 downregulated the tumor progression by TME immunomodulation, leading to a decrease in primary tumor size and metastasis in the peritoneum, liver, and lungs. STAT3, NF-kB, and AKT were the major genes downregulated by of M1EV systems. Tumor-associated macrophages (TAMs) shifted from an M2 phenotype (CD163) to an M1 phenotype (CD68) reducing levels of IL-10, TGF-β and CCL22. Furthermore, malignant cells showed overexpression of FADD, APAF-1, caspase-3, and E-cadherin, and decreased expression of MDR1, survivin, vimentin, and PD-L1 after treatment with systems of M1EVs. The study shows that EVs from M1 antitumor macrophages can transport drugs and enhance their immunomodulatory and antitumor activity by modulating pathways associated with cell proliferation, migration, survival, and drug resistance.

Bio-Inspired Nanocarriers Derived from Stem Cells and Their Extracellular Vesicles for Targeted Drug Delivery

With their seemingly limitless capacity for self-improvement, stem cells have a wide range of potential uses in the medical field. Stem-cell-secreted extracellular vesicles (EVs), as paracrine components of stem cells, are natural nanoscale particles that transport a variety of biological molecules and facilitate cell-to-cell communication which have been also widely used for targeted drug delivery. These nanocarriers exhibit inherent advantages, such as strong cell or tissue targeting and low immunogenicity, which synthetic nanocarriers lack. However, despite the tremendous therapeutic potential of stem cells and EVs, their further clinical application is still limited by low yield and a lack of standardized isolation and purification protocols. In recent years, inspired by the concept of biomimetics, a new approach to biomimetic nanocarriers for drug delivery has been developed through combining nanotechnology and bioengineering. This article reviews the application of biomimetic nanocarriers derived from stem cells and their EVs in targeted drug delivery and discusses their advantages and challenges in order to stimulate future research.

Current understanding of plant-derived exosome-like nanoparticles in regulating the inflammatory response and immune system microenvironment

Natural compounds are widely used to prevent and treat various diseases due to their antioxidant and anti-inflammatory effects. As a kind of promising natural compound, plant-derived exosome-like nanoparticles (PELNs) are extracted from multivesicular bodies of various edible plants, including vegetables, foods, and fruits, and mainly regulate the cellular immune response to pathogen attacks. Moreover, PELNs could remarkably interfere with the dynamic imbalance between pro-inflammatory and anti-inflammatory effects, facilitating to maintain the homeostasis of cellular immune microenvironment. PELNs may serve as a better alternative to animal-derived exosomes (ADEs) owing to their widespread sources, cost-effectiveness, and easy accessibility. PELNs can mediate interspecies communication by transferring various cargoes such as proteins, lipids, and nucleic acids from plant cells to mammalian cells. This review summarizes the biogenesis, composition, and classification of exosomes; the common separation, purification, and characterization methods of PELNs, the potential advantages of PELNs over ADEs; and the anti-inflammatory and immunomodulatory functions of PELNs in various diseases including colitis, cancer, and inflammation-associated metabolic diseases. Additionally, the future perspectives of PELNs and the challenges associated with their clinical application are discussed.

A novel isolation method for spontaneously released extracellular vesicles from brain tissue and its implications for stress-driven brain pathology

BACKGROUND

Extracellular vesicles (EVs), including small EVs (sEVs) such as exosomes, exhibit great potential for the diagnosis and treatment of brain disorders, representing a valuable tool for precision medicine. The latter demands high-quality human biospecimens, especially in complex disorders in which pathological and specimen heterogeneity, as well as diverse individual clinical profile, often complicate the development of precision therapeutic schemes and patient-tailored treatments. Thus, the collection and characterization of physiologically relevant sEVs are of the utmost importance. However, standard brain EV isolation approaches rely on tissue dissociation, which can contaminate EV fractions with intracellular vesicles.

METHODS

Based on multiscale analytical platforms such as cryo-EM, label-free proteomics, advanced flow cytometry, and ExoView analyses, we compared and characterized the EV fraction isolated with this novel method with a classical digestion-based EV isolation procedure. Moreover, EV biogenesis was pharmacologically manipulated with either GW4869 or picrotoxin to assess the validity of the spontaneous-release method, while the injection of labelled-EVs into the mouse brain further supported the integrity of the isolated vesicles.

RESULTS

We hereby present an efficient purification method that captures a sEV-enriched population spontaneously released by mouse and human brain tissue. In addition, we tested the significance of the release method under conditions where biogenesis/secretion of sEVs was pharmacologically manipulated, as well as under animals' exposure to chronic stress, a clinically relevant precipitant of brain pathologies, such as depression and Alzheimer's disease. Our findings show that the released method monitors the drug-evoked inhibition or enhancement of sEVs secretion while chronic stress induces the secretion of brain exosomes accompanied by memory loss and mood deficits suggesting a potential role of sEVs in the brain response to stress and related stress-driven brain pathology.

CONCLUSIONS

Overall, the spontaneous release method of sEV yield may contribute to the characterization and biomarker profile of physiologically relevant brain-derived sEVs in brain function and pathology. Video Abstract.

Extracellular vesicles and Alzheimer's disease in the novel era of Precision Medicine: implications for disease progression, diagnosis and treatment

Extracellular vesicles (EVs), secreted membranous nano-sized particles, are critical intercellular messengers participating in nervous system homeostasis, while recent evidence implicates EVs in Alzheimer's disease (AD) pathogenesis. Specifically, small EVs have been shown to spread toxic proteins, induce neuronal loss, and contribute to neuroinflammation and AD progression. On the other hand, EVs can reduce amyloid-beta deposition and transfer neuroprotective substances between cells, mitigating disease mechanisms. In addition to their roles in AD pathogenesis, EVs also exhibit great potential for the diagnosis and treatment of other brain disorders, representing an advantageous tool for Precision Medicine. Herein, we summarize the contribution of small EVs to AD-related mechanisms and disease progression, as well as their potential as diagnostic and therapeutic agents for AD.

Bioavailability Improvement Strategies for Icariin and Its Derivates: A Review

In recent years, there has been considerable interest in icariin (ICA) and its derivates, icariside II (ICS) and icaritin (ICT), due to their wide range of potential applications in preventing cancer, cardiovascular disease, osteoporosis, delaying the effects of Alzheimer’s disease, treating erectile dysfunction, etc. However, their poor water solubility and membrane permeability, resulting in low bioavailability, dampens their potential beneficial effects. In this regard, several strategies have been developed, such as pharmaceutical technologies, structural transformations, and absorption enhancers. All these strategies manage to improve the bioavailability of the above-mentioned flavonoids, thus increasing their concentration in the desired places. This paper focuses on gathering the latest knowledge on strategies to improve bioavailability for enhancing the efficacy of icariin, icariside II, and icaritin. We conclude that there is an opportunity for many further improvements in this field. To the best of our knowledge, no such review articles scoping the bioavailability improvement of icariin and its derivates have been published to date. Therefore, this paper can be a good starting point for all those who want to deepen their understanding of the field.

Anti-Cancer Role and Therapeutic Potential of Extracellular Vesicles

Cell-cell communication is an important mechanism in biological processes. Extracellular vesicles (EVs), also referred to as exosomes, microvesicles, and prostasomes, are microvesicles secreted by a variety of cells. EVs are nanometer-scale vesicles composed of a lipid bilayer and contain biological functional molecules, such as microRNAs (miRNAs), mRNAs, and proteins. In this review, "EVs" is used as a comprehensive term for vesicles that are secreted from cells. EV research has been developing over the last four decades. Many studies have suggested that EVs play a crucial role in cell-cell communication. Importantly, EVs contribute to cancer malignancy mechanisms such as carcinogenesis, proliferation, angiogenesis, metastasis, and escape from the immune system. EVs derived from cancer cells and their microenvironments are diverse, change in nature depending on the condition. As EVs are thought to be secreted into body fluids, they have the potential to serve as diagnostic markers for liquid biopsy. In addition, cells can encapsulate functional molecules in EVs. Hence, the characteristics of EVs make them suitable for use in drug delivery systems and novel cancer treatments. In this review, the potential of EVs as anti-cancer therapeutics is discussed.

Stability of Erythrocyte-Derived Nanovesicles Assessed by Light Scattering and Electron Microscopy

Extracellular vesicles (EVs) are gaining increasing amounts of attention due to their potential use in diagnostics and therapy, but the poor reproducibility of the studies that have been conducted on these structures hinders their breakthrough into routine practice. We believe that a better understanding of EVs stability and methods to control their integrity are the key to resolving this issue. In this work, erythrocyte EVs (hbEVs) were isolated by centrifugation from suspensions of human erythrocytes that had been aged in vitro. The isolate was characterised by scanning (SEM) and cryo-transmission electron microscopy (cryo-TEM), flow cytometry (FCM), dynamic/static light scattering (LS), protein electrophoresis, and UV-V spectrometry. The hbEVs were exposed to various conditions (pH (4–10), osmolarity (50–1000 mOsm/L), temperature (15–60 °C), and surfactant Triton X-100 (10–500 μM)). Their stability was evaluated by LS by considering the hydrodynamic radius (R_h), intensity of scattered light (I), and the shape parameter (ρ). The morphology of the hbEVs that had been stored in phosphate-buffered saline with citrate (PBS–citrate) at 4 °C remained consistent for more than 6 months. A change in the media properties (50–1000 mOsm/L, pH 4–10) had no significant effect on the R_h (=100–130 nm). At pH values below 6 and above 8, at temperatures above 45 °C, and in the presence of Triton X-100, hbEVs degradation was indicated by a decrease in I of more than 20%. Due to the simple preparation, homogeneous morphology, and stability of hbEVs under a wide range of conditions, they are considered to be a suitable option for EV reference material.

Exosomes as Intercellular Messengers in Hypertension

People living with hypertension have a higher risk of developing heart diseases, and hypertension remains a top cause of mortality. In hypertension, some detrimental changes occur in the arterial wall, which include physiological and biochemical changes. Furthermore, this disease is characterized by turbulent blood flow, increased fluid shear stress, remodeling of the blood vessels, and endothelial dysfunction. As a complex disease, hypertension is thought to be caused by an array of factors, its etiology consisting of both environmental and genetic factors. The Mosaic Theory of hypertension states that many factors, including genetics, environment, adaptive, neural, mechanical, and hormonal perturbations are intertwined, leading to increases in blood pressure. Long-term efforts by several investigators have provided invaluable insight into the physiological mechanisms responsible for the pathogenesis of hypertension, and these include increased activity of the sympathetic nervous system, overactivation of the renin-angiotensin-aldosterone system (RAAS), dysfunction of the vascular endothelium, impaired platelet function, thrombogenesis, vascular smooth muscle and cardiac hypertrophy, and altered angiogenesis. Exosomes are extracellular vesicles released by all cells and carry nucleic acids, proteins, lipids, and metabolites into the extracellular environment. They play a role in intercellular communication and are involved in the pathophysiology of diseases. Since the discovery of exosomes in the 1980s, numerous studies have been carried out to understand the biogenesis, composition, and function of exosomes. In this review, we will discuss the role of exosomes as intercellular messengers in hypertension.