Evaluation of electroporation-induced adverse effects on adipose-derived stem cell exosomes

Potential of Exosomes as Multifunctional Nanocarriers for Targeted Drug Delivery

Exosomes are small vesicles that form when multivesicular bodies fuse with the plasma membrane and are released into body fluids. They play a vital role in facilitating communication between cells by transferring different biomolecules, including DNA, RNA, proteins, and lipids, over both short and long distances. They also function as vital mediators in both states of health and disease, exerting an impact on several physiological processes. Exosomes have been modified to overcome the limitations of natural exosomes to enhance their potential as carriers for drug delivery systems, and these modifications aim to improve the drug delivery efficiency, enhance tissue and organ targeting, and prolong the circulating half-life of exosomes. This review discussed recent advancements in exosome nanotechnology, as well as the progression and use of exosomes for drug delivery. The potential commercialisation and challenges associated with the use of exosome-based drug delivery systems were also discussed, aiming to motivate the development of exosome-based theranostic nanoplatforms and nanotechnology for improved healthcare treatments.

Therapeutic potential of RNA-enriched extracellular vesicles: The next generation in RNA delivery via biogenic nanoparticles

Exosomes are extracellular vesicles (EVs) (∼50-150 nm) that have emerged as promising vehicles for therapeutic applications and drug delivery. These membrane-bound particles, released by all actively dividing cells, have the ability to transfer effector molecules, including proteins, RNA, and even DNA, from donor cells to recipient cells, thereby modulating cellular responses. RNA-based therapeutics, including microRNAs, messenger RNAs, long non-coding RNAs, and circular RNAs, hold great potential in controlling gene expression and treating a spectrum of medical conditions. RNAs encapsulated in EVs are protected from extracellular degradation, making them attractive for therapeutic applications. Understanding the intricate biology of cargo loading and transfer within EVs is pivotal to unlocking their therapeutic potential. This review discusses the biogenesis and classification of EVs, methods for loading RNA into EVs, their advantages as drug carriers over synthetic-lipid-based systems, and the potential applications in treating neurodegenerative diseases, cancer, and viral infections. Notably, EVs show promise in delivering RNA cargo across the blood-brain barrier and targeting tumor cells, offering a safe and effective approach to RNA-based therapy in these contexts.

Current knowledge of hybrid nanoplatforms composed of exosomes and organic/inorganic nanoparticles for disease treatment and cell/tissue imaging

Exosome-nanoparticle hybrid nanoplatforms, can be prepared by combining exosomes with different types of nanoparticles. The main purpose of combining exosomes with nanoparticles is to overcome the limitations of using each of them as drug delivery systems. Using nanoparticles for drug delivery has some limitations, such as high immunogenicity, poor cellular uptake, low biocompatibility, cytotoxicity, low stability, and rapid clearance by immune cells. However, using exosomes as drug delivery systems also has its own drawbacks, such as poor encapsulation efficiency, low production yield, and the inability to load large molecules. These limitations can be addressed by utilizing hybrid nanoplatforms. Additionally, the use of exosomes allows for targeted delivery within the hybrid system. Exosome-inorganic/organic hybrid nanoparticles may be used for both therapy and diagnosis in the future. This may lead to the development of personalized medicine using hybrid nanoparticles. However, there are a few challenges associated with this. Surface modifications, adding functional groups, surface charge adjustments, and preparing nanoparticles with the desired size are crucial to the possibility of preparing exosome-nanoparticle hybrids. Additional challenges for the successful implementation of hybrid platforms in medical treatments and diagnostics include scaling up the manufacturing process and ensuring consistent quality and reproducibility across various batches. This review focuses on various types of exosome-nanoparticle hybrid systems and also discusses the preparation and loading methods for these hybrid nanoplatforms. Furthermore, the potential applications of these hybrid nanocarriers in drug/gene delivery, disease treatment and diagnosis, and cell/tissue imaging are explained.

Therapeutic application of mesenchymal stem cell-derived exosomes in skin wound healing

Wound healing is a complicated obstacle, especially for chronic wounds. Mesenchymal stem cell-derived exosomes may be a promising cell-free approach for treating skin wound healing. Exosomes can accelerate wound healing by attenuating inflammation, promoting angiogenesis, cell proliferation, extracellular matrix production and remodeling. However, many issues, such as off-target effects and high degradation of exosomes in wound sites need to be addressed before applying into clinical therapy. Therefore, the bioengineering technology has been introduced to modify exosomes with greater stability and specific therapeutic property. To prolong the function time and the local concentration of exosomes in the wound bed, the use of biomaterials to load exosomes emerges as a promising strategy. In this review, we summarize the biogenesis and characteristics of exosomes, the role of exosomes in wound healing, and the therapeutic applications of modified-exosomes in wound healing. The challenges and prospects of exosomes in wound healing are also discussed.

Extracellular Vesicles as Drug Delivery System for Cancer Therapy

In recent decades, the pursuit of drug delivery systems has led to the development of numerous synthetic options aimed at enhancing drug efficacy while minimizing side effects. However, the practical application of these systems is often hindered by challenges such as inefficiency, cytotoxicity, and immunogenicity. Extracellular vesicles, natural carriers for drugs, emerge as promising alternatives with distinct advantages over synthetic carriers. Notably, EVs exhibit biocompatibility, low immunogenicity, and inherent tissue-targeting capabilities, thus opening new avenues for drug delivery strategies. This review provides an overview of EVs, including their biogenesis and absorption mechanisms. Additionally, we explore the current research efforts focusing on harnessing their potential as drug carriers, encompassing aspects such as purification techniques, drug loading, and bioengineering for targeted delivery. Finally, we discuss the existing challenges and future prospects of EVs as therapeutic agents in clinical settings. This comprehensive analysis aims to shed light on the potential of EVs as versatile and effective tools for drug delivery, particularly in the realm of cancer therapy.

Engineered exosomes as a prospective therapy for diabetic foot ulcers

Diabetic foot ulcer (DFU), characterized by high recurrence rate, amputations and mortality, poses a significant challenge in diabetes management. The complex pathology involves dysregulated glucose homeostasis leading to systemic and local microenvironmental complications, including peripheral neuropathy, micro- and macro-angiopathy, recurrent infection, persistent inflammation and dysregulated re-epithelialization. Novel approaches to accelerate DFU healing are actively pursued, with a focus on utilizing exosomes. Exosomes are natural nanovesicles mediating cellular communication and containing diverse functional molecular cargos, including DNA, mRNA, microRNA (miRNA), lncRNA, proteins, lipids and metabolites. While some exosomes show promise in modulating cellular function and promoting ulcer healing, their efficacy is limited by low yield, impurities, low loading content and inadequate targeting. Engineering exosomes to enhance their curative activity represents a potentially more efficient approach for DFUs. This could facilitate focused repair and regeneration of nerves, blood vessels and soft tissue after ulcer development. This review provides an overview of DFU pathogenesis, strategies for exosome engineering and the targeted therapeutic application of engineered exosomes in addressing critical pathological changes associated with DFUs.

Exosome theranostics: Comparative analysis of P body and exosome proteins and their mutations for clinical applications

Exosomes are lipid-bilayered vesicles, originating from early endosomes that capture cellular proteins and genetic materials to form multi-vesicular bodies. These exosomes are secreted into extracellular fluids such as cerebrospinal fluid, blood, urine, and cell culture supernatants. They play a key role in intercellular communication by carrying active molecules like lipids, cytokines, growth factors, metabolites, proteins, and RNAs. Recently, the potential of exosomal delivery for therapeutic purposes has been explored due to their low immunogenicity, nano-scale size, and ability to cross cellular barriers. This review comprehensively examines the biogenesis of exosomes, their isolation techniques, and their diverse applications in theranostics. We delve into the mechanisms and methods for loading exosomes with mRNA, miRNA, proteins, and drugs, highlighting their transformative role in delivering therapeutic payloads. Additionally, the utility of exosomes in stem cell therapy is discussed, showcasing their potential in regenerative medicine. Insights into exosome cargo using pre- or post-loading techniques are critical for exosome theranostics. We review exosome databases such as ExoCarta, Expedia, and ExoBCD, which document exosome cargo. From these databases, we identified 25 proteins common to both exosomes and P-bodies, known for mutations in the COSMIC database. Exosome databases do not integrate with mutation analysis programs; hence, we performed mutation analysis using additional databases. Accounting for the mutation status of parental cells and exosomal cargo is crucial in exosome theranostics. This review provides a comprehensive report on exosome databases, proteins common to exosomes and P-bodies, and their mutation analysis, along with the latest studies on exosome-engineered theranostics.

Fluorescent, phosphorescent, magnetic resonance contrast and radioactive tracer labelling of extracellular vesicles

This review focusses on the significance of fluorescent, phosphorescent labelling and tracking of extracellular vesicles (EVs) for unravelling their biology, pathophysiology, and potential diagnostic and therapeutic uses. Various labeling strategies, such as lipid membrane, surface protein, luminal, nucleic acid, radionuclide, quantum dot labels, and metal complex-based stains, are evaluated for visualizing and characterizing EVs. Direct labelling with fluorescent lipophilic dyes is simple but generally lacks specificity, while surface protein labelling offers selectivity but may affect EV-cell interactions. Luminal and nucleic acid labelling strategies have their own advantages and challenges. Each labelling approach has strengths and weaknesses, which require a suitable probe and technique based on research goals, but new tetranuclear polypyridylruthenium(II) complexes as phosphorescent probes have strong phosphorescence, selective staining, and stability. Future research should prioritize the design of novel fluorescent probes and labelling platforms that can significantly enhance the efficiency, accuracy, and specificity of EV labeling, while preserving their composition and functionality. It is crucial to reduce false positive signals and explore the potential of multimodal imaging techniques to gain comprehensive insights into EVs.

Engineered hsa-miR-455-3p-Abundant Extracellular Vesicles Derived from 3D-Cultured Adipose Mesenchymal Stem Cells for Tissue-Engineering Hyaline Cartilage Regeneration

Efforts are made to enhance the inherent potential of extracellular vesicles (EVs) by utilizing 3D culture platforms and engineered strategies for functional cargo-loading. Three distinct types of adipose mesenchymal stem cells-derived EVs (ADSCs-EVs) are successfully isolated utilizing 3D culture platforms consisting of porous gelatin methacryloyl (PG), PG combined with sericin methacryloyl (PG/SerMA), or PG combined with chondroitin sulfate methacryloyl (PG/ChSMA). These correspond to PG-EVs, PG/SerMA-EVs, and PG/ChSMA-EVs, respectively. Unique microRNA (miRNA) profiles are observed in each type of ADSCs-EVs. Notably, PG-EVs encapsulate higher levels of hsa-miR-455-3p and deliver more hsa-miR-455-3p to chondrocytes, which results in the activation of the hsa-miR-455-3p/PAK2/Smad2/3 axis and the subsequent hyaline cartilage regeneration. Furthermore, the functionality of PG-EVs is optimized through engineered strategies, including agomir/lentivirus transfection, electroporation, and Exo-Fect transfection. These strategies, referred to as Agomir-EVs, Lentivirus-EVs, Electroporation-EVs, and Exo-Fect-EVs, respectively, are ranked based on their efficacy in encapsulating hsa-miR-455-3p, delivering hsa-miR-455-3p to chondrocytes, and promoting cartilage formation via the hsa-miR-455-3p/PAK2/Smad2/3 axis. Notably, Exo-Fect-EVs exhibit the highest efficiency. Collectively, the 3D culture conditions and engineered strategies have an impact on the miRNA profiles and cartilage regeneration capabilities of ADSCs-EVs. The findings provide valuable insights into the mechanisms underlying the promotion of cartilage regeneration by ADSCs-EVs.

The Discovery of Extracellular Vesicles and Their Emergence as a Next-Generation Therapy

From their humble discovery as cellular debris to cementing their natural capacity to transfer functional molecules between cells, the long-winded journey of extracellular vesicles (EVs) now stands at the precipice as a next-generation cell-free therapeutic tool to revolutionize modern-day medicine. This perspective provides a snapshot of the discovery of EVs to their emergence as a vibrant field of biology and the renaissance they usher in the field of biomedical sciences as therapeutic agents for cardiovascular pathologies. Rapid development of bioengineered EVs is providing innovative opportunities to overcome biological challenges of natural EVs such as potency, cargo loading and enhanced secretion, targeting and circulation half-life, localized and sustained delivery strategies, approaches to enhance systemic circulation, uptake and lysosomal escape, and logistical hurdles encompassing scalability, cost, and time. A multidisciplinary collaboration beyond the field of biology now extends to chemistry, physics, biomaterials, and nanotechnology, allowing rapid development of designer therapeutic EVs that are now entering late-stage human clinical trials.

Optimizing mesenchymal stem cell extracellular vesicles for chronic wound healing: Bioengineering, standardization, and safety

Chronic wounds represent a significant global burden, afflicting millions with debilitating complications. Despite standard care, impaired healing persists due to factors like persistent inflammation and impaired tissue regeneration. Mesenchymal stem cell (MSC)-derived extracellular vesicles (EVs) offer an innovative regenerative medicine approach, delivering stem cell-derived therapeutic cargo in engineered nanoscale delivery systems. This review examines pioneering bioengineering strategies to engineer MSC-EVs into precision nanotherapeutics for chronic wounds. Emerging technologies like CRISPR gene editing, microfluidic manufacturing, and biomimetic delivery systems are highlighted for their potential to enhance MSC-EV targeting, optimize therapeutic cargo enrichment, and ensure consistent clinical-grade production. However, key hurdles remain, including batch variability, rigorous safety assessment for potential tumorigenicity, immunogenicity, and biodistribution profiling. Crucially, collaborative frameworks harmonizing regulatory science with bioengineering and patient advocacy hold the key to expediting global clinical translation. By overcoming these challenges, engineered MSC-EVs could catalyze a new era of off-the-shelf regenerative therapies, restoring hope and healing for millions afflicted by non-healing wounds.

ADENOSINE INFLUENCES FOXP3 EXPRESSION OF T REGS VIA THE A2AR/CREB PATHWAY IN A MOUSE MODEL OF SEPSIS

ABSTRACT

The adenosine concentration and forkhead box protein (Foxp3) expression in T regulatory cells (T regs ) are increased during sepsis. However, the mechanism by which adenosine induces Foxp3 expression is incompletely understood. A cecal ligation and puncture (CLP) model was constructed using C57BL/J mice. The plasma adenosine concentration and Foxp3 expression in splenic T regs were increased consistently for 15 days after sepsis onset. Analysis of the mean fluorescence intensity of Foxp3 and adenosine concentration in the same mice revealed a linear correlation. In the CLP model, adenosine 2a receptor (A2aR) blockade inhibited Foxp3 expression in T regs . In vitro activation of A2aR promoted Foxp3 expression in T regs and facilitated secretion of extracellular vesicles. Transcriptome sequencing revealed that A2aR blockade led to changes in cyclic adenosine monophosphate response element-binding protein (CREB) transcription in T regs in our sepsis model. Use of adenosine or A2aR agonists promoted CREB expression, CREB phosphorylation at S133, T reg expression of Foxp3, and enhanced inhibition of proliferation of cluster of differentiation (CD)4+ lymphocytes. A2aR blockade or inhibition of CREB expression inhibited Foxp3 expression in T regs . In the CLP model, use of CREB inhibitors could inhibit Foxp3 expression and reduce the bacterial load. In summary, adenosine in sepsis promotes CREB phosphorylation via A2aR which, in turn, upregulates Foxp3 expression in T regs .

Extracellular vesicles-powered immunotherapy: Unleashing the potential for safer and more effective cancer treatment

Cancer treatment has seen significant advancements with the introduction of Onco-immunotherapies (OIMTs). Although some of these therapies have received approval for use, others are either undergoing testing or are still in the early stages of development. Challenges persist in making immunotherapy widely applicable to cancer treatment. To maximize the benefits of immunotherapy and minimize potential side effects, it's essential to improve response rates across different immunotherapy methods. A promising development in this area is the use of extracellular vesicles (EVs) as novel delivery systems. These small vesicles can effectively deliver immunotherapies, enhancing their effectiveness and reducing harmful side effects. This article discusses the importance of integrating nanomedicines into OIMTs, highlighting the challenges with current anti-OIMT methods. It also explores key considerations for designing nanomedicines tailored for OIMTs, aiming to improve upon existing immunotherapy techniques. Additionally, the article looks into innovative approaches like biomimicry and the use of natural biomaterial-based nanocarriers (NCs). These advancements have the potential to transform the delivery of immunotherapy. Lastly, the article addresses the challenges of moving OIMTs from theory to clinical practice, providing insights into the future of using advanced nanotechnology in cancer treatment.

Suppression of gastric cancer cell proliferation by miR-494-3p inhibitor-loaded engineered exosomes

Background

Gastric cancer necessitates novel treatments, and exosomes are promising therapeutic carriers. We created miR-494-3p inhibitor exosomes to assess their effects on gastric cancer cells.

Methods

We conducted a comprehensive investigation into the expression of the oncogenic miR-494-3p in gastric cancer tissues from patients. Subsequently, we engineered miR-494-3p inhibitor-loaded exosomes and characterized their morphology and size through transmission electron microscopy and nanoparticle tracking analysis. We next determined the encapsulation efficiency of the miR-494-3p inhibitor within these exosomes and evaluated the exosomes' structural integrity by quantifying the presence of exosomal markers. Following these validations, we co-cultured miR-494-3p inhibitor exosomes with cancer cells and employed PKH26 staining to visualize the efficient endocytosis of engineered exosomes by gastric cancer cells and assess the impact of these modified exosomes on gastric cancer cell proliferation, apoptosis, migration, and invasion.

Results

Increased expression of miR-494-3p was observed in gastric cancer tissues as compared to controls. Significant low miR-494-3p levels were found within miR-494-3p inhibitor exosomes, signifying effective encapsulation. The incorporation of miR-494-3p inhibitor into engineered exosomes did not alter exosome morphology or size. Finally, PKH26-stained exosomes clearly demonstrated efficient endocytosis by gastric cancer cells, leading to reduced proliferation, migration, invasion, and increased apoptosis.

Conclusion

Our study identifies elevated miR-494-3p in gastric cancer tissues prompting the development of miR-494-3p inhibitor-loaded exosomes with efficient encapsulation. These engineered exosomes demonstrate successful endocytosis by cancer cells. This highlights their potential for therapeutic use in gastric cancer treatment by suppressing proliferation, migration, and invasion while enhancing apoptosis.

Stem cell-derived extracellular vesicles in the therapeutic intervention of Alzheimer's Disease, Parkinson's Disease, and stroke

With the increase in the aging population, the occurrence of neurological disorders is rising. Recently, stem cell therapy has garnered attention due to its convenient sourcing, minimal invasiveness, and capacity for directed differentiation. However, there are some disadvantages, such as poor quality control, safety assessments, and ethical and logistical issues. Consequently, scientists have started to shift their attention from stem cells to extracellular vesicles due to their similar structures and properties. Beyond these parallels, extracellular vesicles can enhance biocompatibility, facilitate easy traversal of barriers, and minimize side effects. Furthermore, stem cell-derived extracellular vesicles can be engineered to load drugs and modify surfaces to enhance treatment outcomes. In this review, we summarize the functions of native stem cell-derived extracellular vesicles, subsequently review the strategies for the engineering of stem cell-derived extracellular vesicles and their applications in Alzheimer's disease, Parkinson's disease, and stroke, and discuss the challenges and solutions associated with the clinical translation of stem cell-derived extracellular vesicles.

Tonicity-induced cargo loading into extracellular vesicles

The current challenge in using extracellular vesicles (EVs) as drug delivery vehicles is to precisely control their membrane permeability, specifically in the ability to switch between permeable and impermeable states without compromising their integrity and functionality. Here, we introduce a rapid, efficient, and gentle loading method for EVs based on tonicity control (TC) using a lab-on-a-disc platform. In this technique, a hypotonic solution was used for temporarily permeabilizing a membrane ("on" state), allowing the influx of molecules into EVs. The subsequent isotonic washing led to an impermeable membrane ("off" state). This loading cycle enables the loading of different cargos into EVs, such as doxorubicin hydrochloride (Dox), ssDNA, and miRNA. The TC approach was shown to be more effective than traditional methods such as sonication or extrusion, with loading yields that were 4.3-fold and 7.2-fold greater, respectively. Finally, the intracellular assessments of miRNA-497-loaded EVs and doxorubicin-loaded EVs confirmed the superior performance of TC-prepared formulations and demonstrated the impact of encapsulation heterogeneity on the therapeutic outcome, signifying potential opportunities for developing novel exosome-based therapeutic systems for clinical applications.

Exosomes in renal cell carcinoma: challenges and opportunities

Renal cell carcinoma (RCC) is the most common type of kidney cancer that accounts for approximately 2-3% of adult malignancies. Among the primary treatment methods for this type of cancer are surgery and targeted treatment. Still, due to less than optimal effectiveness, there are problems such as advanced distant metastasis, delayed diagnosis, and drug resistance that continue to plague patients. In recent years, therapeutic advances have increased life expectancy and effective treatment in renal cell carcinoma patients. One of these methods is the use of stem cells. Although the therapeutic effects of stem cells, especially mesenchymal stem cells, are still impressive, today, extracellular vesicles (EVs) as carrying molecules and various mediators in intercellular communications, having a central role in tumorigenesis, metastasis, immune evasion, and drug response, and on the other hand, due to its low immunogenicity and strong regulatory properties of the immune system, has received much attention from researchers and doctors. Despite the increasing interest in exosomes as the most versatile type of EVs, the heterogeneity of their efficacy presents challenges and, on the other hand, exciting opportunities for diagnostic and clinical interventions.In the upcoming article, we will review the various aspects of exosomes' effects in the prevention, treatment, and progress of renal cell carcinoma and also ways to optimize them to strengthen their positive sides.

Role of long noncoding RNAs in pathological cardiac remodeling after myocardial infarction: An emerging insight into molecular mechanisms and therapeutic potential

Myocardial infarction (MI) is the leading cause of heart failure (HF), accounting for high mortality and morbidity worldwide. As a consequence of ischemia/reperfusion injury during MI, multiple cellular processes such as oxidative stress-induced damage, cardiomyocyte death, and inflammatory responses occur. In the next stage, the proliferation and activation of cardiac fibroblasts results in myocardial fibrosis and HF progression. Therefore, developing a novel therapeutic strategy is urgently warranted to restrict the progression of pathological cardiac remodeling. Recently, targeting long non-coding RNAs (lncRNAs) provided a novel insight into treating several disorders. In this regard, numerous investigations have indicated that several lncRNAs could participate in the pathogenesis of MI-induced cardiac remodeling, suggesting their potential therapeutic applications. In this review, we summarized lncRNAs displayed in the pathophysiology of cardiac remodeling after MI, emphasizing molecular mechanisms. Also, we highlighted the possible translational role of lncRNAs as therapeutic targets for this condition and discussed the potential role of exosomes in delivering the lncRNAs involved in post-MI cardiac remodeling.

Edible Plant-Derived Extracellular Vesicles for Oral mRNA Vaccine Delivery

Nucleic acid delivery through extracellular vesicles (EVs) is a well-preserved evolutionary mechanism in all life kingdoms including eukaryotes, prokaryotes, and plants. EVs naturally allow horizontal transfer of native as well as exogenous functional mRNAs, which once incorporated in EVs are protected from enzymatic degradation. This observation has prompted researchers to investigate whether EVs from different sources, including plants, could be used for vaccine delivery. Several studies using human or bacterial EVs expressing mRNA or recombinant SARS-CoV-2 proteins showed induction of a humoral and cell mediated immune response. Moreover, EV-based vaccines presenting the natural configuration of viral antigens have demonstrated advantages in conferring long-lasting immunization and lower toxicity than synthetic nanoparticles. Edible plant-derived EVs were shown to be an alternative to human EVs for vaccine delivery, especially via oral administration. EVs obtained from orange juice (oEVs) loaded with SARS-CoV-2 mRNAs protected their cargo from enzymatic degradation, were stable at room temperature for one year, and were able to trigger a SARS-CoV-2 immune response in mice. Lyophilized oEVs containing the S1 mRNA administered to rats via gavage induced a specific humoral immune response with generation of blocking antibodies, including IgA and Th1 lymphocyte activation. In conclusion, mRNA-containing oEVs could be used for developing new oral vaccines due to optimal mucosal absorption, resistance to stress conditions, and ability to stimulate a humoral and cellular immune response.

Enhancing osteoporosis treatment with engineered mesenchymal stem cell-derived extracellular vesicles: mechanisms and advances

As societal aging intensifies, the incidence of osteoporosis (OP) continually rises. OP is a skeletal disorder characterized by reduced bone mass, deteriorated bone tissue microstructure, and consequently increased bone fragility and fracture susceptibility, typically evaluated using bone mineral density (BMD) and T-score. Not only does OP diminish patients' quality of life, but it also imposes a substantial economic burden on society. Conventional pharmacological treatments yield limited efficacy and severe adverse reactions. In contemporary academic discourse, mesenchymal stem cells (MSCs) derived extracellular vesicles (EVs) have surfaced as auspicious novel therapeutic modalities for OP. EVs can convey information through the cargo they carry and have been demonstrated to be a crucial medium for intercellular communication, playing a significant role in maintaining the homeostasis of the bone microenvironment. Furthermore, various research findings provide evidence that engineered strategies can enhance the therapeutic effects of EVs in OP treatment. While numerous reviews have explored the progress and potential of EVs in treating degenerative bone diseases, research on using EVs to address OP remains in the early stages of basic experimentation. This paper reviews advancements in utilizing MSCs and their derived EVs for OP treatment. It systematically examines the most extensively researched MSC-derived EVs for treating OP, delving not only into the molecular mechanisms of EV-based OP therapy but also conducting a comparative analysis of the strengths and limitations of EVs sourced from various cell origins. Additionally, the paper emphasizes the technical and engineering strategies necessary for leveraging EVs in OP treatment, offering insights and recommendations for future research endeavors.

Engineered Extracellular Vesicles in Wound Healing: Design, Paradigms, and Clinical Application

The severe quality of life and economic burden imposed by non-healing skin wounds, infection risks, and treatment costs are affecting millions of patients worldwide. To mitigate these challenges, scientists are relentlessly seeking effective treatment measures. In recent years, extracellular vesicles (EVs) have emerged as a promising cell-free therapy strategy, attracting extensive attention from researchers. EVs mediate intercellular communication, possessing excellent biocompatibility and stability. These features make EVs a potential tool for treating a plethora of diseases, including those related to wound repair. However, there is a growing focus on the engineering of EVs to overcome inherent limitations such as low production, relatively fixed content, and targeting capabilities of natural EVs. This engineering could improve both the effectiveness and specificity of EVs in wound repair treatments. In light of this, the present review will introduce the latest progress in the design methods and experimental paradigms of engineered EVs applied in wound repair. Furthermore, it will comprehensively analyze the current clinical research status and prospects of engineered EVs within this field.

Effective exosomes in breast cancer: focusing on diagnosis and treatment of cancer progression

Breast cancer (BC) is the most prevalent aggressive malignant tumor in women worldwide and develops from breast tissue. Although cutting-edge treatment methods have been used and current mortality rates have decreased, BC control is still not satisfactory. Clarifying the underlying molecular mechanisms will help clinical options. Extracellular vesicles known as exosomes mediate cellular communication by delivering a variety of biomolecules, including proteins, oncogenes, oncomiRs, and even pharmacological substances. These transferable bioactive molecules can alter the transcriptome of target cells and affect signaling pathways that are related to tumors. Numerous studies have linked exosomes to BC biology, including therapeutic resistance and the local microenvironment. Exosomes' roles in tumor treatment resistance, invasion, and BC metastasis are the main topics of discussion in this review.

Exosome-based engineering strategies for the diagnosis and treatment of oral and maxillofacial diseases

Oral and maxillofacial diseases are one of the most prevalent diseases in the world, which not only seriously affect the health of patients' oral and maxillofacial tissues, but also bring serious economic and psychological burdens to patients. Therefore, oral and maxillofacial diseases require effective treatment. Traditional treatments have limited effects. In recent years, nature exosomes have attracted increasing attention due to their ability to diagnose and treat diseases. However, the application of nature exosomes is limited due to low yield, high impurities, lack of targeting, and high cost. Engineered exosomes can be endowed with better comprehensive therapeutic properties by modifying exosomes of parent cells or directly modifying exosomes, and biomaterial loading exosomes. Compared with natural exosomes, these engineered exosomes can achieve more effective diagnosis and treatment of oral and maxillary system diseases, and provide reference and guidance for clinical application. This paper reviews the engineering modification methods of exosomes and the application of engineered exosomes in oral and maxillofacial diseases and looks forward to future research directions.

CRISPR-Cas9 Engineered Extracellular Vesicles for the Treatment of Dominant Progressive Hearing Loss

Clinical translation of gene therapy has been challenging, due to limitations in current delivery vehicles such as traditional viral vectors. Herein, we report the use of gRNA:Cas9 ribonucleoprotein (RNP) complexes engineered extracellular vesicles (EVs) for in vivo gene therapy. By leveraging a novel high-throughput microfluidic droplet-based electroporation system (μDES), we achieved 10-fold enhancement of loading efficiency and more than 1000-fold increase in processing throughput on loading RNP complexes into EVs (RNP-EVs), compared with conventional bulk electroporation. The flow-through droplets serve as enormous bioreactors for offering millisecond pulsed, low-voltage electroporation in a continuous-flow and scalable manner, which minimizes the Joule heating influence and surface alteration to retain natural EV stability and integrity. In the Shaker-1 mouse model of dominant progressive hearing loss, we demonstrated the effective delivery of RNP-EVs into inner ear hair cells, with a clear reduction of Myo7ash1 mRNA expression compared to RNP-loaded lipid-like nanoparticles (RNP-LNPs), leading to significant hearing recovery measured by auditory brainstem responses (ABR).

Research Advances of Engineered Exosomes as Drug Delivery Carrier

Exosomes are nanoscale vesicles secreted by living cells that have similar membrane composition to parental cells and carry a variety of proteins, lipids, and nucleic acids. Therefore, exosomes have certain biological activities and play an important role in intercellular communication. On the basis of its potential as a carrier for drug delivery systems, exosomes have been engineered to compensate for the shortage of natural exosomes through various engineering strategies for improving drug delivery efficiency, enhancing targeting to tissues and organs, and extending the circulating half-life of exosomes. This review focuses on the engineered exosomes loading drugs through different strategies, discussions on exosome surface modification strategies, and summarizes the advantages and disadvantages of different strategies. In addition, this review provides an overview of the recent applications of engineered exosomes in a number of refractory and relapsable diseases. This review has the potential to provide a reference for further research and development of engineered exosomes.

Engineered exosomes for tissue regeneration: from biouptake, functionalization and biosafety to applications

Exosomes are increasingly recognized as important effector molecules that regulate intercellular signaling pathways. Notably, certain types of exosomes can induce therapeutic responses, including cell proliferation, angiogenesis, and tissue repair. The use of exosomes in therapy is a hot spot in current research, especially in regenerative medicine. Despite the therapeutic potential, problems have hindered their success in clinical applications. These shortcomings include low concentration, poor targeting and limited loading capability. To fully realize their therapeutic potential, certain modifications are needed in native exosomes. In the present review, we summarize the exosome modification and functionalization strategies. In addition, we provide an overview of potential clinical applications and highlight the issues associated with the biosafety and biocompatibility of engineered exosomes in applications.

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

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

Prospective applications of extracellular vesicle-based therapies in regenerative medicine: implications for the use of dental stem cell-derived extracellular vesicles

In the 21st century, research on extracellular vesicles (EVs) has made remarkable advancements. Recently, researchers have uncovered the exceptional biological features of EVs, highlighting their prospective use as therapeutic targets, biomarkers, innovative drug delivery systems, and standalone therapeutic agents. Currently, mesenchymal stem cells stand out as the most potent source of EVs for clinical applications in tissue engineering and regenerative medicine. Owing to their accessibility and capability of undergoing numerous differentiation inductions, dental stem cell-derived EVs (DSC-EVs) offer distinct advantages in the field of tissue regeneration. Nonetheless, it is essential to note that unmodified EVs are currently unsuitable for use in the majority of clinical therapeutic scenarios. Considering the high feasibility of engineering EVs, it is imperative to modify these EVs to facilitate the swift translation of theoretical knowledge into clinical practice. The review succinctly presents the known biotherapeutic effects of odontogenic EVs and the underlying mechanisms. Subsequently, the current state of functional cargo loading for engineered EVs is critically discussed. For enhancing EV targeting and in vivo circulation time, the review highlights cutting-edge engineering solutions that may help overcome key obstacles in the clinical application of EV therapeutics. By presenting innovative concepts and strategies, this review aims to pave the way for the adaptation of DSC-EVs in regenerative medicine within clinical settings.

Exosomes: Mediators of cellular communication in potentially malignant oral lesions and head and neck cancers

Exosomes are a unique type of extracellular vesicles that contain a plethora of biological cargo such as miRNA, mRNA, long non-coding RNA, DNA, proteins and lipids. Exosomes serve as very effective means of intercellular communication. Due the presence of a lipid bilayer membrane, exosomes are resistant to degradation and are highly stable. This makes them easily identifiable in blood and other bodily fluids such as saliva. The exosomes that are secreted from a parent cell directly release their contents into the cytoplasm of a recipient cell and influence their cellular activity and function. Exosomes can also transfer their content between cancer cells and normal cells and regulate the tumor microenvironment. Exosomes play a vital role in tumor growth, tumor invasion and metastasis. Exosomes provide a multitude of molecular and genetic information and have become valuable indicators of disease activity at the cellular level. This review explores the molecular characteristics of exosomes and the role that exosomes play in the tumorigenesis pathway of potentially malignant oral lesions and head and neck cancers The application of exosomes in the treatment of oral cancers is also envisioned. Exosomes are very small and can easily pass through various biological barriers, making them very good delivery vectors for therapeutic drugs as well as to selectively induce DNA's mRNA and miRNAs into targeted cancer cells.

Emerging functions and clinical applications of exosomal microRNAs in diseases

Exosomes are an important group of extracellular vesicles that transfer several kinds of biomolecules and facilitate cell-cell communication. The content of exosomes, particularly the amounts of microRNA (miRNAs) inside these vesicles, demonstrates a disease-specific pattern reflecting pathogenic processes and may be employed as a diagnostic and prognostic marker. miRNAs may enter recipient cells through exosomes and generate a RISC complex that can cause degradation of the target mRNAs or block translation of their corresponding proteins. Therefore, exosome-derived miRNAs constitute an important mechanism of gene regulation in recipient cells. The miRNA content of exosomes can be used as an important tool in the detection of diverse disorders, particularly cancers. This research field has an important situation in cancer diagnosis. In addition, exosomal microRNAs offer a great deal of promise in the treatment of human disorders. However, there are still certain challenges to be resolved. The most important challenges are as follow: the detection of exosomal miRNAs should be standardized, exosomal miRNAs-associated studies should be conducted in large number of clinical samples, and experiment settings and detection criteria should be consistent across different labs. The goal of this article is to present an overview of the effects of exosome-derived microRNAs on a variety of diseases, including gastrointestinal, pulmonary, neurological, and cardiovascular diseases, with a particular emphasis on malignancies.

Strategies for Engineering of Extracellular Vesicles

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

Advances in modification and delivery of nucleic acid drugs

Nucleic acid-based drugs, such as RNA and DNA drugs, exert their effects at the genetic level. Currently, widely utilized nucleic acid-based drugs include nucleic acid aptamers, antisense oligonucleotides, mRNA, miRNA, siRNA and saRNA. However, these drugs frequently encounter challenges during clinical application, such as poor stability, weak targeting specificity, and difficulties in traversing physiological barriers. By employing chemical modifications of nucleic acid structures, it is possible to enhance the stability and targeting specificity of certain nucleic acid drugs within the body, thereby improving delivery efficiency and reducing immunogenicity. Moreover, utilizing nucleic acid drug carriers can facilitate the transportation of drugs to lesion sites, thereby aiding efficient intracellular escape and promoting drug efficacy within the body. Currently, commonly employed delivery carriers include virus vectors, lipid nanoparticles, polymer nanoparticles, inorganic nanoparticles, protein carriers and extracellular vesicles. Nevertheless, individual modifications or delivery carriers alone are insufficient to overcome numerous obstacles. The integration of nucleic acid chemical modifications with drug delivery systems holds promise for achieving enhanced therapeutic effects. However, this approach also presents increased technical complexity and clinical translation costs. Therefore, the development of nucleic acid drug carriers and nucleic acid chemical modifications that are both practical and simple, while maintaining high efficacy, low toxicity, and precise nucleic acid delivery, has become a prominent research focus in the field of nucleic acid drug development. This review comprehensively summarizes the advancements in nucleic acid-based drug modifica-tions and delivery systems. Additionally, strategies to enhance nucleic acid drug delivery efficiency are discussed, with the aim of providing valuable insights for the translational application of nucleic acid drugs.

Exosomes as a Nano-Carrier for Chemotherapeutics: A New Era of Oncology

Despite the considerable advancements in oncology, cancer remains one of the leading causes of death worldwide. Drug resistance mechanisms acquired by cancer cells and inefficient drug delivery limit the therapeutic efficacy of available chemotherapeutics drugs. However, studies have demonstrated that nano-drug carriers (NDCs) can overcome these limitations. In this sense, exosomes emerge as potential candidates for NDCs. This is because exosomes have better organotropism, homing capacity, cellular uptake, and cargo release ability than synthetic NDCs. In addition, exosomes can serve as NDCs for both hydrophilic and hydrophobic chemotherapeutic drugs. Thus, this review aimed to summarize the latest advances in cell-free therapy, describing how the exosomes can contribute to each step of the carcinogenesis process and discussing how these nanosized vesicles could be explored as nano-drug carriers for chemotherapeutics.

Recent Trends in the Use of Small Extracellular Vesicles as Optimal Drug Delivery Vehicles in Oncology

Small extracellular vesicles (sEVs) are produced by most cells and play an important role in cell-to-cell communication and maintaining cellular homeostasis. Their ability to transfer biological cargo to target cells makes them a promising tool for cancer drug delivery. Advances in sEV engineering, EV mimetics, and ligand-directed targeting have improved the efficacy of anticancer drug delivery and functionality. EV-based RNA interference and hybrid miRNA transfer have also been extensively used in various preclinical cancer models. Despite these developments, gaps still exist in our understanding of using sEVs to treat solid tumor malignancies effectively. This article provides an overview of the last five years of sEV research and its current status for the efficient and targeted elimination of cancer cells, which could advance cancer research and bring sEV formulations into clinical use.

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.

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.

Extracellular vesicles: The next generation in gene therapy delivery

Extracellular vesicles (EVs) are esteemed as a promising delivery vehicle for various genetic therapeutics. They are relatively inert, non-immunogenic, biodegradable, and biocompatible. At least in rodents, they can even transit challenging bodily hurdles such as the blood-brain barrier. Constitutively shed by all cells and with the potential to interact specifically with neighboring and distant targets, EVs can be engineered to carry and deliver therapeutic molecules such as proteins and RNAs. EVs are thus emerging as an elegant in vivo gene therapy vector. Deeper understanding of basic EV biology-including cellular production, EV loading, systemic distribution, and cell delivery-is still needed for effective harnessing of these endogenous cellular nanoparticles as next-generation nanodelivery tools. However, even a perfect EV product will be challenging to produce at clinical scale. In this regard, we propose that vector transduction technologies can be used to convert cells either ex vivo or directly in vivo into EV factories for stable, safe modulation of gene expression and function. Here, we extrapolate from the current EV state of the art to a bright potential future using EVs to treat genetic diseases that are refractory to current therapeutics.

miR-92a-1-5p enriched prostate cancer extracellular vesicles regulate osteoclast function via MAPK1 and FoxO1

BACKGROUND

We have previously reported that extracellular vesicles (EVs) derived from osteoblastic, osteoclastic and mixed prostate cancer cells promote osteoclast differentiation and inhibit osteoblast differentiation via transferring miR-92a-1-5p. In the present study, we focused on engineering miR-92a-1-5p into EVs and determining any therapeutic roles and mechanisms of the engineered EVs.

METHODS

A stable prostate cancer cell line (MDA PCa 2b) overexpressing miR-92a-1-5p was constructed by lentivirus, and EVs were isolated by ultracentrifugation. The overexpression of miR-92a-1-5p in both cells and EVs was tested using qPCR. Osteoclast function was evaluated by Trap staining, mRNA expression of osteoclastic markers ctsk and trap, immunolabeling of CTSK and TRAP and microCT using either in vitro and in vivo assays. Target gene of miR-92a-1-5p was proved by a dual-luciferase reporter assay system. siRNAs were designed and used for transient expression in order to determine the role of downstream genes on osteoclast differentiation.

RESULTS

Stable overexpression cells of miRNA-92a-5p was associated with EVs upregulating this microRNA, as confirmed by qPCR. Further, miR-92a-1-5p enriched EVs promote osteoclast differentiation in vitro by reducing MAPK1 and FoxO1 expression, associated with increased osteoclast function as shown by TRAP staining and mRNA expression of osteoclast functional genes. siRNA targeting MAPK1 or FoxO1 resulted in similar increase in osteoclast function. In vivo, the miR-92a-1-5p enriched EVs given via i.v. injection promote osteolysis, which was associated with reduction of MAPK1 and FoxO1 expression in bone marrow.

CONCLUSION

These experiments suggest that miR-92a-1-5p enriched EVs regulate osteoclast function via reduction of MAPK1 and FoxO1.

Milk/colostrum exosomes: A nanoplatform advancing delivery of cancer therapeutics

Chemotherapeutics continue to play a central role in the treatment of a wide variety of cancers. Conventional chemotherapy involving bolus intravenous doses results in severe side effects - in some cases life threatening - delayed toxicity and compromised quality-of-life. Attempts to deliver small drug molecules using liposomes, polymeric nanoparticles, micelles, lipid nanoparticles, etc. have produced limited nanoformulations for clinical use, presumably due to a lack of biocompatibility of the material, costs, toxicity, scalability, and/or lack of effective administration. Naturally occurring small extracellular vesicles, or exosomes, may offer a solution and a viable system for delivering cancer therapeutics. Combined with their inherent trafficking ability and versatility of cargo capacity, exosomes can be engineered to specifically target cancerous cells, thereby minimizing off-target effects, and increasing the efficacy of cancer therapeutics. Exosomal formulations have mitigated the toxic effects of several drugs in murine cancer models. In this article, we review studies related to exosomal delivery of both small molecules and biologics, including siRNA to inhibit specific gene expression, in the pursuit of effective cancer therapeutics. We focus primarily on bovine milk and colostrum exosomes as the cancer therapeutic delivery vehicles based on their high abundance, cost effectiveness, scalability, high drug loading, functionalization of exosomes for targeted delivery, and lack of toxicity. While bovine milk exosomes may provide a new platform for drug delivery, extensive comparison to other nanoformulations and evaluation of long-term toxicity will be required to fully realize its potential.

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

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

Extracellular Vesicles for Therapeutic Nucleic Acid Delivery: Loading Strategies and Challenges

Extracellular vesicles (EVs) are membrane vesicles released into the extracellular milieu by cells of various origins. They contain different biological cargoes, protecting them from degradation by environmental factors. There is an opinion that EVs have a number of advantages over synthetic carriers, creating new opportunities for drug delivery. In this review, we discuss the ability of EVs to function as carriers for therapeutic nucleic acids (tNAs), challenges associated with the use of such carriers in vivo, and various strategies for tNA loading into EVs.

Recent Advancements on the Use of Exosomes as Drug Carriers for the Treatment of Glioblastoma

Glioblastoma (GBM) is the most common and aggressive cancer of the brain. Presently, GBM patients have a poor prognosis, and therapy primarily aims to extend the life expectancy of affected patients. The current treatment of GBM in adult cases and high-grade gliomas in the pediatric population involves a multimodal approach that includes surgical resection followed by simultaneous chemo/radiotherapy. Exosomes are nanoparticles that transport proteins and nucleic acids and play a crucial role in mediating intercellular communication. Recent evidence suggests that these microvesicles may be used as biological carriers and offer significant advantages in targeted therapy. Due to their inherent cell-targeting properties, circulation stability, and biocompatibility, exosomes are emerging as promising new carriers for drugs and biotherapeutics. Furthermore, these nanovesicles are a repository of potential diagnostic and prognostic markers. In this review, we focus on the therapeutic potentials of exosomes in nano-delivery and describe the latest evidence of their use as a therapeutic tool in GBM.

Engineered Cancer-Derived Small Extracellular Vesicle-Liposome Hybrid Delivery System for Targeted Treatment of Breast Cancer

Cancer-derived small extracellular vesicles (sEVs) may be a promising drug delivery system that targets cancer cells due to their unique features, such as native homing ability, biological barrier crossing capability, and low immune response. However, the oncogenic cargos within them pose safety concerns, hence limiting their application thus far. We proposed using an electroporation-based strategy to extract the endogenous cargos from cancer-derived sEVs and demonstrated that their homing ability was still retained. A membrane fusion technique was used to fuse these sEVs with liposomes to form hybrid particles, which possessed both benefits of sEVs and liposomes. Anti-EGFR monoclonal antibodies were modified on the hybrid particles to improve their targeting ability further. The engineered hybrid particles showed higher drug loading ability that is 33.75 and 43.88% higher than that of liposomes and sEVs, respectively, and improved targeting ability by 52.23% higher than hybrid particles without modification. This delivery system showed >90% cell viability and enhanced treatment efficiency with 91.58 and 79.26% cell migration inhibition rates for the miR-21 inhibitor and gemcitabine, respectively.

"Find-eat" strategy targeting endothelial cells via receptor functionalized apoptotic body nanovesicle

Endothelial cell (EC) injury plays a key role in the chronic wound process. A long-term hypoxic microenvironment hinders the vascularization of ECs, thus delaying wound healing. In this study, CX3CL1-functionalized apoptotic body nanovesicles (nABs) were constructed. The "Find-eat" strategy was implemented through a receptor-ligand combination to target ECs that highly express CX3CR1 in the hypoxic microenvironment, therefore amplifying the "Find-eat" signal and promoting angiogenesis. Apoptotic bodies (ABs) were obtained by chemically inducing apoptosis of adipose-derived stem cells (ADSCs), and then functionalized nABs containing deferoxamine (DFO-nABs) were obtained through a series of steps, including optimized hypotonic treatment, mild ultrasound, drug mixing and extrusion treatment. In vitro experiments showed that nABs had good biocompatibility and an effective "Find-eat" signal via CX3CL1/CX3CR1 to induce ECs in the hypoxic microenvironment, thereby promoting cell proliferation, cell migration and tube formation. In vivo experiments showed that nABs could promote the rapid closure of wounds, release the "Find-eat" signal to target ECs and realize the sustained release of angiogenic drugs to promote new blood vessel formation in diabetic wounds. These receptor-functionalized nABs, which can target ECs by releasing dual signals and achieve the sustained release of angiogenic drugs, may provide a novel strategy for chronic diabetic wound healing.

Exosomes as natural nanocarrier-based drug delivery system: recent insights and future perspectives

Exosomes are nanosized (size ~ 30-150 nm) natural vesicular structures released from cells by physiological processes or pathological circumstances. Exosomes are growing in popularity as a result of their many benefits over conventional nanovehicles, including their ability to escape homing in the liver or metabolic destruction and their lack of undesired accumulation before reaching their intended targets. Various therapeutic molecules, including nucleic acids, have been incorporated into exosomes by different techniques, many of which have shown satisfactory performance in various diseases. Surface-modified exosomes are a potentially effective strategy, and it increases the circulation time and produces the specific drug target vehicle. In this comprehensive review, we describe composition exosomes biogenesis and the role of exosomes in intercellular signaling and cell-cell communications, immune responses, cellular homeostasis, autophagy, and infectious diseases. In addition, we discuss the role of exosomes as diagnostic markers, and their therapeutic and clinical implications. Furthermore, we addressed the challenges and outstanding developments in exosome research and discuss future perspectives. In addition to the current status of exosomes as a therapeutic carrier, the lacuna in the clinical development lifecycles along with the possible strategies to fill the lacuna have been addressed.

Single-particle assessment of six different drug-loading strategies for incorporating doxorubicin into small extracellular vesicles

Extracellular vesicles (EVs) have emerged as an attractive drug delivery system owing to their natural roles in intercellular communication. On account of the large intrinsic heterogeneity of EVs, it is highly desirable to evaluate not only the encapsulation efficiency but also the alteration of biological functionality after the drug-loading process at the single-particle level. However, the nanoscale size of EVs poses a great challenge. Taking advantage of nano-flow cytometry (nFCM) in the multiparameter analysis of single EVs as small as 40 nm, six commonly used drug-loading strategies (coincubation, electroporation, extrusion, freeze-thawing, sonication, and surfactant treatment) were exploited by employing doxorubicin (Dox) as the model drug. Encapsulation ratio, EV concentration, drug content, and membrane proteins of Dox-loaded EVs were measured at the single-particle level. Our data indicated that coincubation and electroporation outperformed other methods with an encapsulation ratio of approximately 45% and a higher Dox content in single EVs. Interestingly, the labeling ratios of membrane proteins indicated that varying degrees of damage to the surface proteins of EVs occurred upon extrusion, freeze-thawing, sonication, and surfactant treatment. Confocal fluorescence microscopy and flow cytometry analysis revealed that Dox-loaded EVs prepared by electroporation induced the strongest apoptosis followed by coincubation. These results correlated well with their cellular uptake rate and fundamentally with the Dox encapsulation efficiency of single EVs. nFCM provides a rapid and sensitive platform for single-particle assessment of drug-loading strategies for incorporating drugs into EVs.

Exosome-Based Carrier for RNA Delivery: Progress and Challenges

In the last few decades, RNA-based drugs have emerged as a promising candidate to specifically target and modulate disease-relevant genes to cure genetic defects. The key to applying RNA therapy in clinical trials is developing safe and effective delivery systems. Exosomes have been exploited as a promising vehicle for drug delivery due to their nanoscale size, high stability, high biocompatibility, and low immunogenicity. We reviewed and summarized the progress in the strategy and application of exosome-mediated RNA therapy. The challenges of exosomes as a carrier for RNA drug delivery are also elucidated in this article. RNA molecules can be loaded into exosomes and then delivered to targeted cells or tissues via various biochemical or physical approaches. So far, exosome-mediated RNA therapy has shown potential in the treatment of cancer, central nervous system disorders, COVID-19, and other diseases. To further exploit the potential of exosomes for RNA delivery, more efforts should be made to overcome both technological and logistic problems.

Potential of Mesenchymal Stromal Cell-Derived Extracellular Vesicles as Natural Nanocarriers: Concise Review

Intercellular communication, through direct and indirect cell contact, is mandatory in multicellular organisms. These last years, the microenvironment, and in particular, transfer by extracellular vesicles (EVs), has emerged as a new communication mechanism. Different biological fluids and cell types are common sources of EVs. EVs play different roles, acting as signalosomes, biomarkers, and therapeutic agents. As therapeutic agents, MSC-derived EVs display numerous advantages: they are biocompatible, non-immunogenic, and stable in circulation, and they are able to cross biological barriers. Furthermore, EVs have a great potential for drug delivery. Different EV isolation protocols and loading methods have been tested and compared. Published and ongoing clinical trials, and numerous preclinical studies indicate that EVs are safe and well tolerated. Moreover, the latest studies suggest their applications as nanocarriers. The current review will describe the potential for MSC-derived EVs as drug delivery systems (DDS) in disease treatment, and their advantages. Thereafter, we will outline the different EV isolation methods and loading techniques, and analyze relevant preclinical studies. Finally, we will describe ongoing and published clinical studies. These elements will outline the benefits of MSC-derived EV DDS over several aspects.

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.

Exploring the role of exosomes in rheumatoid arthritis

In prosperous countries, autoimmune illnesses affect minimum 7% of the community. Rheumatoid Arthritis (RA) as an autoimmune illness is thought to be induced through a variety of genomic, physiological, and biological factors. Many experts in the field of nanomedicine have looked to stem cells as a viable strategy to repair human tissue; however, exosomes have demonstrated greater potential in recent years. Exosomes, produced from stem cells in particular, have exhibited a high propensity to give therapeutic effects. To resist local cellular stress, they are secreted in a paracrine manner from cells. As a result, exosomes produced from stem cells can provide enormous health uses. If treatment is not given, autoantibodies produce synovial inflammation and arthritis, which can lead to chronic inflammation, and impairment. Exosomes could be administered for the treatment of RA, by acting as therapeutic vectors. Exosomes are murine extracellular vesicles that influence biological mechanisms and signal transduction by transporting genetic and protein components. Diseases like RA and bone fractures could be treated using cell-free therapeutic strategies if exosomes could be isolated from stem cells efficiently and packaged with specific restorative substances. To get to this position, many breakthroughs must be achieved, and the following review summarises the most recent developments in stem cell-derived exosomes, with a focus on the important literature on exosome dynamics in RA.