Extracellular vesicles as drug delivery systems: Why and how?

Incorporation of doxorubicin into plant-derived nanovesicles: process monitoring and activity assessment

Extracellular vesicles (EVs) are an experimental class of drug carriers. Alternative sources of EVs are currently being explored to overcome limitations related to their manufacturing from mesenchymal stem cells. In this work, Citrus limon-derived EVs were tested as carriers for the widely used chemotherapeutic drug - doxorubicin (DOX). Capillary electrophoresis (CE) and nanoplasmonic sensing (NPS) were developed for the quality control of DOX-EV preparations. It was found that the CE method enables simultaneous detection of free and incorporated DOX and allows assessing the stability of the preparations and the drug leakage. NPS, on the other hand, demonstrated that DOX is accumulated in the interfacial region of the carrier. The activity of DOX-loaded EVs was tested on HeLa (cervical cancer cells) and HEK293T (human embryonic kidney cells) cell lines. It was found that DOX incorporation into plant-derived EVs virtually does not affect the drug's cytotoxicity to HeLa cells but significantly decreases DOX activity against HEK293T cell line.

Engineered extracellular vesicles loaded in boronated cyclodextrin framework for pulmonary delivery

Extracellular vesicles (EVs) are promising therapeutic carriers for their ideal nano-size and intrinsic biocompatibility, while rapid clearance and limited targeting ability are the major setbacks of EVs. With minimal absorption into the systemic circulation, inhalation for pulmonary disease therapy minimizes off-target toxicity to other organs and offers a safe and effective treatment for respiratory disorders. Herein, a nano-grid carrier made of boronated cyclodextrin framework (BCF) was prepared for pH/H2O2 responsive release of EVs. A novel design of cyclo (Arg-Gly-Asp-D-Tyr-Lys) peptide (RGD)-modified milk-derived EVs (mEVs) loaded in the BCF particles (RGD-mEVs@BCF) was developed for pulmonary delivery. The results indicated that RGD-mEVs showed superior anti-inflammatory activity in contrast with mEVs in vitro. BCF was able to capture and protect RGD-mEVs, which showed extended-release profiles and responsiveness. Pulmonary administration of RGD-mEVs@BCF showed favorable biocompatibility in rats. Taken together, RGD-mEVs@BCF features biocompatibility and pH-responsive mEVs release as a therapeutic platform for pulmonary delivery of drugs to treat lung diseases, especially for inflammatory diseases.

Brain-targeting drug delivery systems: The state of the art in treatment of glioblastoma

Glioblastoma (GBM) is the most prevalent primary malignant brain tumor, characterized by a high mortality rate and a poor prognosis. The blood-brain barrier (BBB) and the blood-tumor barrier (BTB) present significant obstacles to the efficacy of tumor-targeted pharmacotherapy, thereby impeding the therapeutic potential of numerous candidate drugs. Targeting delivery of adequate doses of drug across the BBB to treat GBM has become a prominent research area in recent years. This emphasis has driven the exploration and evaluation of diverse technologies for GBM pharmacotherapy, with some already undergoing clinical trials. This review provides a thorough overview of recent advancements and challenges in targeted drug delivery for GBM treatment. It specifically emphasizes systemic drug administration strategies to assess their potential and limitations in GBM treatment. Furthermore, this review highlights promising future research directions in the development of intelligent drug delivery systems aimed at overcoming current challenges and enhancing therapeutic efficacy against GBM. These advancements not only support foundational research on targeted drug delivery systems for GBM but also offer methodological approaches for future clinical applications.

Nanotechnology in Parkinson's Disease: overcoming drug delivery challenges and enhancing therapeutic outcomes

The global prevalence of Parkinson's Disease (PD) is on the rise, driven by an ageing population and ongoing environmental conditions. To gain a better understanding of PD pathogenesis, it is essential to consider its relationship with the ageing process, as ageing stands out as the most significant risk factor for this neurodegenerative condition. PD risk factors encompass genetic predisposition, exposure to environmental toxins, and lifestyle influences, collectively increasing the chance of PD development. Moreover, early and precise PD diagnosis remains elusive, relying on clinical assessments, neuroimaging techniques, and emerging biomarkers. Conventional management of PD involves dopaminergic medications and surgical interventions, but these treatments often become less effective over time and do not address disease treatment. Challenges persist due to the blood-brain barrier's (BBB) impermeability, hindering drug delivery. Recent advancements in nanotechnology offer promising novel approaches for PD management. Various drug delivery systems (DDS), including nanosized polymers, lipid-based carriers, and nanoparticles (such as metal/metal oxide, protein, and carbonaceous particles), aim to enhance drug and gene delivery. These modifications seek to improve BBB permeability, ultimately benefiting PD patients. This review underscores the critical role of ageing in PD development and explores how age-related neuronal decline contributes to substantia nigra loss and PD manifestation in susceptible individuals. The review also highlights the advancements and ongoing challenges in nanotechnology-based therapies for PD.

Engineered Extracellular Vesicles Modified by Angiopep-2 Peptide Promote Targeted Repair of Spinal Cord Injury and Brain Inflammation

Engineered extracellular vesicles play an increasingly important role in the treatment of spinal cord injury. In order to prepare more effective engineered extracellular vesicles, we biologically modified M2 microglia. Angiopep-2 (Ang2) is an oligopeptide that can target the blood-brain barrier. Through single-cell sequencing and immunofluorescence experiments, we confirmed that the expression of LRP-1, the targeted receptor of Ang2, was elevated after spinal cord injury. Subsequently, we integrated the Ang2 peptide segment into M2 microglia to obtain Ang2-EVs, which could successfully target the site of spinal cord injury. However, in order to improve the function of Ang2-EVs, we pretreated M2 microglia with melatonin, which has anti-inflammatory effects, to obtain M-Ang2-EVs. The results of single-nucleus sequencing of the mouse spinal cord verified that neurons and OPCs gradually transformed into subtypes related to nerve repair functions after treatment with M-Ang2-EVs. This is consistent with the sequencing and enrichment analysis of miRNAs contained in M-Ang2-EVs. We further verified through experiments that M-Ang2-EVs can promote microglia/macrophages to phagocytose sphingomyelin, promote axon remyelination and axon elongation, and maintain the integrity of the blood-spinal barrier. Since Ang2 can also target the blood-brain barrier, we found that M-Ang2-EVs can also reduce brain inflammation that results from spinal cord injury. Our study applied the Angiopep-2 peptide to spinal cord injury to enhance the targeting of injured cells, and successfully construct engineered extracellular vesicles that can target the spinal cord injury site and the brain.

Harnessing Extracellular Vesicles for Stabilized and Functional IL-10 Delivery in Macrophage Immunomodulation

Extracellular vesicles (EVs) are gaining recognition as promising therapeutic carriers for immune modulation. We investigated the potential of EVs derived from HEK293FT cells to stabilize and deliver interleukin-10 (IL-10), a key anti-inflammatory cytokine. Using minicircle (MC) DNA vectors, we achieved IL-10 overexpression and efficient incorporation into EVs, yielding superior stability compared to free, recombinant IL-10 protein. Detailed biophysical and functional analyses revealed that IL-10+ EVs contain both monomeric and oligomeric forms of IL-10 on their external surface and encapsulated within vesicles. IL-10+ EVs suppressed inflammatory cytokine expression in pro-inflammatory macrophages (from two to 14-fold compared to naïve EVs) without inducing anti-inflammatory polarization, demonstrating a distinct immunosuppressive mechanism. Interestingly, naïve EVs from non-transfected cells also exhibited significant anti-inflammatory effects, suggesting that the intrinsic bioactive cargo of EVs substantially contributes to their function, complicating the interpretation of IL-10-specific effects. Size-based fractionation analyses of IL-10+ large EVs (lEVs), small EVs (sEVs), and non-vesicular extracellular particles (NVEPs) revealed IL-10 presence across all fractions, predominantly in monomeric form, with anti-inflammatory activity distributed among subpopulations. Anion exchange chromatography successfully enriched IL-10+ exosomes while retaining immunomodulatory effects. However, the shared properties of naïve and IL-10+ exosomes underscore the complexity of their immunomodulatory functions. These findings highlight the therapeutic potential of EVs while emphasizing the need to disentangle the contributions of engineered cytokines from endogenous vesicular components.

The roles and therapeutic potential of exosomal non-coding RNAs in microglia-mediated intercellular communication

Exosomes, which are small extracellular vesicles (sEVs), serve as versatile regulators of intercellular communication in the progression of various diseases, including neurological disorders. Among the diverse array of cargo they carry, non-coding RNAs (ncRNAs) play key regulatory roles in various pathophysiological processes. Exosomal ncRNAs derived from distinct cells modulate their reciprocal crosstalk locally or remotely, thereby mediating neurological diseases. Nevertheless, the emerging role of exosomal ncRNAsin microglia-mediated phenotypes remains largely unexplored. This review aims to summarise the biological functions of exosomal ncRNAs and the molecular mechanisms that underlie their impact on microglia-mediated intercellular communication, modulating neuroinflammation and synaptic functions within the landscape of neurological disorders. Furthermore, this review comprehensively described the potential applications of exosomal ncRNAs as diagnostic and prognostic biomarkers, as well as innovative therapeutic targets for the treatment of neurological diseases.

Baricitinib-loaded EVs promote alopecia areata mouse hair regrowth by reducing JAK-STAT-mediated inflammation and promoting hair follicle regeneration

Alopecia areata (AA) is a common and recurrent type of hair loss. Despite oral administration of baricitinib exerts a good effect on refractory AA, the long-term administration of baricitinib carries significant side effects, poor compliance, and the efficacy is difficult to maintain after drug withdrawal. Therefore, the exploration of a safe and effective local administration of baricitinib to treat AA is of great clinical importance. However, baricitinib has a large molecular weight and is barely soluble in water, while the hair follicle lies deep, thus conventional topical dosage forms are ineffective. This study investigated the efficacy of local injection of baricitinib-loaded mesenchymal stem cell exosomes (EVs) in the treatment of AA. First, we constructed baricitinib loaded EVs (EV-B) and established AA mouse model by intravenously injection with murine INF-γ according to previous literature reports. The therapeutic effects of EV-B on hair regrowth were recorded and the underlying mechanism was also analyzed by Luminex protein biochip test and western-blot. Compared to control group, the baricitinib, EV and EV-B groups exhibited improved hair coverage in the AA mouse model. Besides, EV-B group achieved the optimal effect. The underlying mechanism might be attributed to the improvement of drug delivery efficiency as well as the synergistic effect of EVs, leading to better inhibition of JAK-STAT pathway and upregulation of the Wnt/β-catenin pathway. Our findings proved the effectiveness of EV-B on the treatment of AA, and might provide a new therapeutic approach for AA in future clinical application.

Zwitterionic polymers with high serum tolerance for intracellular protein delivery

Cationic polymers have been widely developed as carriers for intracellular protein delivery, but face tough challenges such as poor serum tolerance and inevitable material toxicity. Here, we present a type of phase-separating polymer with an anionic surface to address the above issues. A cationic dendrimer is first modified with a hydrophobic moiety to obtain a pH-responsive amphiphilic polymer, which is further conjugated with anionic benzenesulphonate at different grafting degrees. The benzenesulphonate modification facilely changes the hydrophobicity of the polymer and reduces the material cytotoxicity. Interestingly, the polymer can co-assemble with cargo proteins to form nanovesicles for intracellular protein delivery. The benzenesulphonate on the polymer surface bolsters the resistance of polymers to serum proteins, allowing the materials to maintain high delivery efficacy in culture media containing abundant serum proteins. This study provides a facile strategy to design materials with high serum tolerance for intracellular protein delivery.

Exploring the potential of plasma and adipose mesenchymal stem cell-derived extracellular vesicles as novel platforms for neuroinflammation therapy

Persistent reactive oxygen species (ROS) and neuroinflammation contribute to the onset and progression of neurodegenerative diseases, underscoring the need for targeted therapeutic strategies to mitigate these effects. Extracellular vesicles (EVs) show promise in drug delivery due to their biocompatibility, ability to cross biological barriers, and specific interactions with cell and tissue receptors. In this study, we demonstrated that human plasma-derived EVs (pEVs) exhibit higher brain-targeting specificity, while adipose-derived mesenchymal stem cells EVs (ADMSC-EVs) offer regenerative and immunomodulatory properties. We further investigated the potential of these EVs as therapeutic carriers for brain-targeted drug delivery, using Donepezil (DNZ) as the model drug. DNZ, a cholinesterase inhibitor commonly used for Alzheimer's disease (AD), also has neuroprotective and anti-inflammatory properties. The size of EVs used ranged from 50 to 300 nm with a surface charge below -30 mV. Both formulations showed rapid cellular internalization, without toxicity, and the ability to cross the blood-brain barrier (BBB) in a zebrafish model. The have analyzed the anti-inflammatory and antioxidant actions of pEVs-DNZ and ADMSC-EVs-DNZ in the presence of lipopolysaccharide (LPS). ADMSC-EVs significantly reduced the inflammatory mediators released by HMC3 microglial cells while treatment with pEVs-DNZ and ADMSC-EVs-DNZ lowered both phagocytic activity and ROS levels in these cells. In vivo experiments using zebrafish larvae revealed that both EV formulations reduced microglial proliferation and exhibited antioxidant effects. Overall, this study highlights the potential of EVs loaded with DNZ as a novel approach for treating neuroinflammation underlying various neurodegenerative diseases.

Extracellular Vesicles as Tools for Crossing the Blood-Brain Barrier to Treat Lysosomal Storage Diseases

Extracellular vesicles (EVs) are nanosized, membrane-bound structures that have emerged as promising tools for drug delivery, especially in the treatment of lysosomal storage disorders (LSDs) with central nervous system (CNS) involvement. This review highlights the unique properties of EVs, such as their biocompatibility, capacity to cross the blood-brain barrier (BBB), and potential for therapeutic cargo loading, including that of enzymes and genetic material. Current therapies for LSDs, like enzyme replacement therapy (ERT), often fail to address neurological symptoms due to their inability to cross the BBB. EVs offer a viable alternative, allowing for targeted delivery to the CNS and improving therapeutic outcomes. We discuss recent advancements in the engineering and modification of EVs to enhance targeting, circulation time and cargo stability, and provide a detailed overview of their application in LSDs, such as Gaucher and Fabry diseases, and Sanfilippo syndrome. Despite their potential, challenges remain in scaling production, ensuring isolation purity, and meeting regulatory requirements. Future developments will focus on overcoming these barriers, paving the way for the clinical translation of EV-based therapies in LSDs and other CNS disorders.

Harnessing extracellular vesicle heterogeneity for diagnostic and therapeutic applications

Extracellular vesicles (EVs) are diverse nanoparticles with large heterogeneity in size and molecular composition. Although this heterogeneity provides high diagnostic value for liquid biopsy and confers many exploitable functions for therapeutic applications in cancer detection, wound healing and neurodegenerative and cardiovascular diseases, it has also impeded their clinical translation-hence heterogeneity acts as a double-edged sword. Here we review the impact of subpopulation heterogeneity on EV function and identify key cornerstones for addressing heterogeneity in the context of modern analytical platforms with single-particle resolution. We outline concrete steps towards the identification of key active biomolecules that determine EV mechanisms of action across different EV subtypes. We describe how such knowledge could accelerate EV-based therapies and engineering approaches for mimetic artificial nanovesicle formulations. This approach blunts one edge of the sword, leaving only a single razor-sharp edge on which EV heterogeneity can be exploited for therapeutic applications across many diseases.

Extracellular nanovesicles as neurotherapeutics for central nervous system disorders

INTRODUCTION

The blood-brain barrier (BBB) is a highly selective structure that protects the central nervous system (CNS) while hindering the delivery of many therapeutic agents. This presents a major challenge in treating neurological disorders, such as multiple sclerosis, where effective drug delivery to the brain is crucial for improving patient outcomes. Innovative strategies are urgently needed to address this limitation.

AREAS COVERED

This review explores the potential of extracellular vesicles (EVs) as innovative drug delivery systems capable of crossing the BBB. EVs are membrane-bound vesicles derived from cells, tissues, or plant materials, offering natural biocompatibility and therapeutic potential. Recent studies investigating the permeability of EVs and their mechanisms for crossing the BBB, such as transcytosis, are summarized. Special emphasis is placed on plant-derived EVs (PDEVs) due to their unique advantages in drug delivery. Challenges related to the large-scale production and therapeutic consistency of EVs are also discussed.

EXPERT OPINION

EVs, particularly PDEVs, hold significant promise as scalable and noninvasive systems for CNS drug delivery. However, critical barriers such as improving standardization techniques, manufacturing processes and addressing scalability must be overcome to facilitate clinical translation. Collaborative efforts in research and innovation will be pivotal in realizing the therapeutic potential of EVs for neurological conditions.

Advances in RNA-Based Therapeutics: Challenges and Innovations in RNA Delivery Systems

Nucleic acids, as carriers of genetic information, have found wide applications in both medical and research fields, including gene editing, disease diagnostics, and drug development. Among various types of nucleic acids, RNA offers greater versatility compared to DNA due to its single-stranded structure, ability to directly encode proteins, and high modifiability for targeted therapeutic and regulatory applications. Despite its promising potential in biomedicine, RNA-based medicine still faces several challenges. Notably, one of the most significant technical hurdles is achieving efficient and targeted RNA delivery while minimizing immune responses. Various strategies have been developed for RNA delivery, including viral vectors, virus-like particles (VLPs), lipid nanoparticles (LNPs), and extracellular vesicles (EVs). In this review, we explore the applications of these delivery methods, highlight their advantages and limitations, and discuss recent research advancements, providing insights for the future of RNA-based therapeutics.

Immunotherapy and delivery systems for melanoma

Melanoma is a highly malignant tumor of melanocyte origin that is prone to early metastasis and has a very poor prognosis. Early melanoma treatment modalities are mainly surgical, and treatment strategies for advanced or metastatic melanoma contain chemotherapy, radiotherapy, targeted therapy and immunotherapy. The efficacy of chemotherapy and radiotherapy has been unsatisfactory due to low sensitivity and strong toxic side effects. And targeted therapy is prone to drug resistance, so its clinical application is limited. Melanoma has always been the leader of immunotherapy for solid tumors, and how to maximize the role of immunotherapy and how to implement immunotherapy more accurately are still urgent to be explored. This review summarizes the common immunotherapies and applications for melanoma, illustrates the current research status of melanoma immunotherapy delivery systems, and discusses the advantages and disadvantages of each delivery system and its prospects for clinical application.

A state-of-the-art review of the recent advances in drug delivery systems for different therapeutic agents in periodontitis

Periodontitis (PD) is a chronic gum illness that may be hard to cure for a number of reasons, including the fact that no one knows what causes it, the side effects of anti-microbial treatment, and how various kinds of bacteria interact with one another. As a result, novel therapeutic approaches for PD treatment must be developed. Additionally, supplementary antibacterial regimens, including local and systemic medication administration of chemical agents, are necessary for deep pockets to assist with mechanical debridement of tooth surfaces. As our knowledge of periodontal disease and drug delivery systems (DDSs) grows, new targeted delivery systems like extracellular vesicles, lipid-based nanoparticles (NPs), metallic NPs, and polymer NPs have been developed. These systems aim to improve the targeting and precision of PD treatments while reducing the systemic side effects of antibiotics. Nanozymes, photodermal therapy, antibacterial metallic NPs, and traditional PD therapies have all been reviewed in this research. Medicinal herbs, antibiotics, photothermal therapy, nanozymes, antibacterial metallic NPs, and conventional therapies for PD have all been examined in this research. After that, we reviewed the key features of many innovative DDSs and how they worked for PD therapy. Finally, we have discussed the advantages and disadvantages of these DDSs.

Biogenesis and functional implications of extracellular vesicles in cancer metastasis

Extracellular vesicles (EVs) play a crucial role in the complex process of cancer metastasis by facilitating cellular communication and influencing the microenvironment to promote the spread and establishment of cancer cells in distant locations. This paper explores the process of EV biogenesis, explaining their various sources that range from endosomal compartments to plasma membrane shedding. It also discusses the complex mechanisms that control the sorting of cargo within EVs, determining their chemical makeup. We investigate the several functions of EVs in promoting the spread of cancer to other parts of the body. These functions include influencing the immune system, creating environments that support the formation of metastases before they occur, and aiding in the transformation of cells from an epithelial to a mesenchymal state. Moreover, we explore the practical consequences of EV cargo, such as nucleic acids, proteins, and lipids, in influencing the spread of cancer cells, from the beginning of invasion to the creation of secondary tumor sites. Examining recent progress in the field of EV-based diagnostics and treatments, we explore the potential of EVs as highly promising biomarkers for predicting the course of cancer and as targets for therapeutic intervention. This review aims to provide a complete understanding of the biology of EVs in the context of cancer metastasis. By unravelling the nuances of EV biology, it seeks to pave the way for new tactics in cancer detection, treatment, and management.

Extracellular vesicles-based vaccines: Emerging immunotherapies against cancer

Cancer vaccines are promising therapeutic approaches to enhance specific T-cell immunity against most solid tumors. By stimulating anti-tumor immunity, clearing minimal residual disease, and minimizing adverse effects, these vaccines target tumor cells and are effective when combined with immune checkpoint blockade or other immunotherapies. However, the development of tumor cell-based vaccines faces quality issues due to poor immunogenicity, tumor heterogeneity, a suppressive tumor immune microenvironment, and ineffective delivery methods. In contrast, extracellular vesicles (EVs), naturally released by cells, are considered the ideal drug carriers and vaccine platforms. EVs offer highly organ-specific targeting, induce broader and more effective immune responses, and demonstrate superior tissue delivery ability. The development of EV vaccines is crucial for advancing cancer immunotherapy. Compared to cell-based vaccines, EV vaccines produced under Good Manufacturing Practices (GMP) offer advantages such as high safety, ease of preservation and transport, and a wide range of sources. This review summarizes the latest research findings on EV vaccine and potential applications in this field. It also highlights novel neoantigens for the development of EV vaccines against cancer.

Exosomal long non-coding RNAs in lung cancer: A review

Lung cancer is one of the most threatening malignancies among the different kinds of tumors. The incidence and mortality rate are increasing especially in male. Advances in diagnosis and treatment have been achieve in recent years. However, the lung tumor cells also developing chemo- and radio-resistance. Novel approaches and new treatments are stilled needed to develop for early diagnosis and treatment. Recently, long non-coding RNAs (lncRNAs) original exosomes were proved different expression in lung tumor, which mediate multiple biological processes and is responsible for tumor proliferation and metastasis. In this review, we focus on the emerging roles of both lncRNAs and exosomal lncRNAs in lung cancer and their roles on angiogenesis, metastasis, diagnosis, drug resistance, and immune regulation of lung cancer. Exosome lncRNAs were proved to serve as regulatory factors for gene expression, mediating intercellular communication, and participating in the occurrence and development of various diseases. In addition, exosomes lnc RNA has advantages on the early diagnosis of lung cancer, tumor cell metastasis, drug resistance, and immune regulation. Exosome lncRNAs an provide some unique ideas on how to improve the efficiency of diagnosis and treatment of lung cancer in the future.

Exosomes in infectious diseases: insights into leishmaniasis pathogenesis, immune modulation, and therapeutic potential

Leishmaniasis continues to be a critical international health issue due to the scarcity of efficient treatment and the development of drug tolerance. New developments in the research of extracellular vesicles (EVs), especially exosomes, have revealed novel disease management approaches. Exosomes are small vesicles that transport lipids, nucleic acids, and proteins in cell signalling. Its biogenesis depends on several cellular processes, and their functions in immune response, encompassing innate and adaptive immunity, underline their function in the pathogen-host interface. Exosomes play a significant role in the pathogenesis of some parasitic infections, especially Leishmaniasis, by helping parasites escape host immunity and promote disease progression. This article explains that in the framework of parasitic diseases, exosomes can act as master regulators that define the pathogenesis of the disease, as illustrated by the engagement of exosomes in the Leishmaniasis parasite and immune escape processes. Based on many published articles on Leishmaniasis, this review aims to summarize the biogenesis of exosomes, the properties of the cargo in exosomes, and the modulation of immune responses. We delve deeper into the prospect of using exosomes for the therapy of Leishmaniasis based on the possibility of using these extracellular vesicles for drug delivery and as diagnostic and prognostic biomarkers. Lastly, we focus on the recent research perspectives and future developments, underlining the necessity to continue the investigation of exosome-mediated approaches in Leishmaniasis treatment. Thus, this review intends to draw attention to exosomes as a bright new perspective in the battle against this disabling affliction.

Apoptotic body based biomimetic hybrid nanovesicles to attenuate cytokine storms for sepsis treatment

Sepsis is a severe immune response to pathogens that is associated with high mortality rate and a paucity of efficacious treatment options. It is characterized by the hyperactivation of macrophages and the occurrence of cytokine storms. Given the anti-inflammatory properties of M2 macrophages and their derived apoptotic bodies (AB), as well as the specific uptake of these by macrophages, a novel approach was employed to combine AB with artificial liposomes to create apoptotic body based biomimetic hybrid nanovesicles (L-AB). The L-AB effectively inherited "eat me" signaling molecules on the surface of the AB, thereby facilitating their targeted uptake by macrophages in both in vitro and in vivo settings. The administration of L-AB for the delivery of dexamethasone effectively augmented the therapeutic efficacy of the drug, mitigated macrophage hyperactivation and tissue damage in vivo, and consequently enhanced the survival rate of septic mice. Taken together, these findings suggest that the apoptotic body biomimetic nanovesicles may represent a potential drug delivery system capable of specifically targeting macrophages for the treatment of sepsis.

The Lymphatic Vascular System in Extracellular Vesicle-Mediated Tumor Progression

Tumor growth and progression require molecular interactions between malignant and host cells. In recent years, extracellular vesicles (EVs) emerged as an important pillar of such interactions, carrying molecular information from their donor cells to distant recipient cells. Thereby, the phenotype and function of the recipient cells are altered, which may facilitate tumor immune escape and tumor metastasis to other organs through the formation of pre-metastatic niches. A prerequisite for these effects of tumor cell-derived EVs is an efficient transport system from the site of origin to the body periphery. Here, we highlight the role of the lymphatic vascular system in the distribution and progression-promoting functions of tumor cell-derived EVs. Importantly, the lymphatic vascular system is the primary drainage system for interstitial fluid and its soluble, particulate, and cellular contents, and therefore represents the principal route for regional (i.e., to tumor-draining lymph nodes) and systemic distribution of EVs derived from solid tumors. Furthermore, recent studies highlighted the tumor-draining lymph node as a crucial site where tumor-derived EVs exert their effects. A deeper mechanistic understanding of how EVs gain access to the lymphatic vasculature, how they interact with their recipient cells in tumor-draining lymph nodes and beyond, and how they induce phenotypic and functional maladaptation will be instrumental to identify new molecular targets and conceive innovative approaches for cancer therapy.

Engineering exosomes from fibroblast growth factor 1 pre-conditioned adipose-derived stem cells promote ischemic skin flaps survival by activating autophagy

Background

The recovery of ischemic skin flaps is a major concern in clinical settings. The purpose of this study is to evaluate the effects of engineered exosomes derived from FGF1 pre-conditioned adipose-derived stem cells (FEXO) on ischemic skin flaps.

Method

6 patients who suffered from pressure ulcer at stage 4 and underwent skin flaps surgery were recruited in this study to screen the potential targets of ischemic skin flaps in FGF family. FGF1 was co-incubated with adipose stem cells, and ultracentrifugation was applied to extract FEXO. Transcriptome sequencing analysis was used to determine the most effective microRNA in FEXO. Animal skin flaps models were established in our study to verify the effects of FEXO. Immunofluorescence (IF), western blotting (WB) and other molecular strategy were used to evaluate the effects and mechanism of FEXO.

Results

FGF1 was expected to be the therapeutic and diagnostic target of ischemic skin flaps, but there is still some deficiency in rescuing skin flaps. FEXO significantly improved the viability of RPSFs and endothelial cells by inhibiting oxidative stress and alleviating apoptosis and pyroptosis through augmenting autophagy flux. In addition, FEXO inhibited the over-activated inflammation responses. Transcriptome sequencing analysis showed that miR-183-5p was significantly elevated in FEXO, and inhibiting miR-183-5p resulted in impaired protective effects of autophagy in skin flaps. The exosomal miR-183-5p markedly enhanced cell viability, inhibited oxidative stress and alleviated apoptosis and pyroptosis in endothelial cells by targeting GPR137 through Pi3k/Akt/mTOR pathway, indicating that GPR137 could also be a therapeutic target of ischemic skin flap. It was also notabale that FGF1 increased the number of exosomes by upregulating VAMP3, which may be a promising strategy for clinical translation.

Conclusion

FEXO markedly improved the survivial rate of ischemic skin flaps through miR-183-5p/GPR137/Pi3k/Akt/mTOR axis, which would be a promising strategy to rescue ischemic skin flaps.

Nature's carriers: leveraging extracellular vesicles for targeted drug delivery

With the rapid development of drug delivery systems, extracellular vesicles (EVs) have emerged as promising stars for improving targeting abilities and realizing effective delivery. Numerous studies have shown when compared to conventional strategies in targeted drug delivery (TDD), EVs-based strategies have several distinguished advantages besides targeting, such as participating in cell-to-cell communications and immune response, showing high biocompatibility and stability, penetrating through biological barriers, etc. In this review, we mainly focus on the mass production of EVs including the challenges and strategies for scaling up EVs production in a cost-effective and reproducible manner, the loading and active targeting methods, and examples of EVs as vehicles for TDD in consideration of potential safety and regulatory issues associated. We also conclude and discuss the rigor and reproducibility of EVs production, the current research status of the application of EVs-based strategies to targeted drug delivery, clinical conversion prospects, and existing chances and challenges.

Recent advances in bacterial outer membrane vesicles: Effects on the immune system, mechanisms and their usage for tumor treatment

Tumor treatment remains a significant medical challenge, with many traditional therapies causing notable side effects. Recent research has led to the development of immunotherapy, which offers numerous advantages. Bacteria inherently possess motility, allowing them to preferentially colonize tumors and modulate the tumor immune microenvironment, thus influencing the efficacy of immunotherapy. Bacterial outer membrane vesicles (OMVs) secreted by gram-negative bacteria are nanoscale lipid bilayer structures rich in bacterial antigens, pathogen-associated molecular patterns (PAMPs), various proteins, and vesicle structures. These features allow OMVs to stimulate immune system activation, generate immune responses, and serve as efficient drug delivery vehicles. This dual capability enhances the effectiveness of immunotherapy combined with chemotherapy or phototherapy, thereby improving anticancer drug efficacy. Current research has concentrated on engineering OMVs to enhance production yield, minimize cytotoxicity, and improve the safety and efficacy of treatments. Consequently, OMVs hold great promise for applications in tumor immunotherapy, tumor vaccine development, and drug delivery. This article provides an overview of the structural composition and immune mechanisms of OMVs, details various OMVs modification strategies, and reviews the progress in using OMVs for tumor treatment and their anti-tumor mechanisms. Additionally, it discusses the challenges faced in translating OMV-based anti-tumor therapies into clinical practice, aiming to provide a comprehensive understanding of OMVs' potential for in-depth research and clinical application.

Exosomes in Central Nervous System Diseases: A Comprehensive Review of Emerging Research and Clinical Frontiers

Exosomes, nano-sized lipid bilayer vesicles, have garnered significant attention as mediators of cell communication, particularly within the central nervous system (CNS). Their unique properties, including high stability, low immunogenicity, and the ability to traverse the blood-brain barrier (BBB), position them as promising tools for understanding and addressing CNS diseases. This comprehensive review delves into the biogenesis, properties, composition, functions, and isolation of exosomes, with a particular focus on their roles in cerebrovascular diseases, neurodegenerative disorders, and CNS tumors. Exosomes are involved in key pathophysiological processes in the CNS, including angiogenesis, inflammation, apoptosis, and cellular microenvironment modification. They demonstrate promise in mitigating ischemic injury, regulating inflammatory responses, and providing neuroprotection across various CNS conditions. Furthermore, exosomes carry distinct biomolecules, offering a novel method for the early diagnosis and monitoring of CNS diseases. Despite their potential, challenges such as complex extraction processes, the heterogeneity of exosomal contents, and targeted delivery limitations hinder their clinical application. Nevertheless, exosomes hold significant promise for advancing our understanding of CNS diseases and developing novel therapeutic strategies. This manuscript significantly contributes to the field by highlighting exosomes' potential in advancing our understanding of CNS diseases, underscoring their unique value in developing novel therapeutic strategies and mediating cellular communication.

Extracellular Vesicles in Idiopathic Pulmonary Fibrosis: Pathogenesis, Biomarkers and Innovative Therapeutic Strategies

Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive, and irreversible interstitial lung disease caused by aberrant deposition of extracellular matrix in the lungs with significant morbidity and mortality. The therapeutic choices for IPF remain limited. Extracellular vesicles (EVs), as messengers for intercellular communication, are cell-secreted lipid bilayer nanoscale particles found in body fluids, and regulate the epithelial phenotype and profibrotic signaling pathways by transporting bioactive cargo to recipients in the pathogenesis of IPF. Furthermore, an increasing number of studies suggests that EVs derived from stem cells can be employed as a cell-free therapeutic approach for IPF, given their intrinsic tissue-homing capabilities and regeneration characteristics. This review highlights new sights of EVs in the pathogenesis of IPF, their potential as diagnostic and prognostic biomarkers, and prospects as novel drug delivery systems and next-generation therapeutics against IPF. Notably, bringing engineering strategies to EVs holds great promise for enhancing the therapeutic effect of anti-pulmonary fibrosis and promoting clinical transformation.

Targeted delivery of extracellular vesicles: the mechanisms, techniques and therapeutic applications

Extracellular vesicles (EVs) are cell-derived vesicles with a phospholipid bilayer measuring 50-150 nm in diameter with demonstrated therapeutic potentials. Limitations such as the natural biodistribution (mainly concentrated in the liver and spleen) and short plasma half-life of EVs present significant challenges to their clinical translation. In recent years, growing research indicated that engineered EVs with enhanced targeting to lesion sites have markedly promoted therapeutic efficacy. However, there is a dearth of systematic knowledge on the recent advances in engineering EVs for targeted delivery. Herein, we provide an overview of the targeting mechanisms, engineering techniques, and clinical translations of natural and engineered EVs in therapeutic applications. Enrichment of EVs at lesion sites may be achieved through the recognition of tissue markers, pathological changes, and the circumvention of mononuclear phagocyte system (MPS). Alternatively, external stimuli, including magnetic fields and ultrasound, may also be employed. EV engineering techniques that fulfill targeting functions includes genetic engineering, membrane fusion, chemical modification and physical modification. A comparative statistical analysis was conducted to elucidate the discrepancies between the diverse techniques on size, morphology, stability, targeting and therapeutic efficacy in vitro and in vivo. Additionally, a summary of the registered clinical trials utilizing EVs from 2010 to 2023 has been provided, with a full discussion on the perspectives. This review provides a comprehensive overview of the mechanisms and techniques associated with targeted delivery of EVs in therapeutic applications to advocate further explorations of engineered EVs and accelerate their clinical applications.

Physical, biochemical, and biological characterization of olive-derived lipid nanovesicles for drug delivery applications

Extracellular vesicles (EVs) have shown great promise as drug delivery system (DDS). However, their complex and costly production limit their development for clinical use. Interestingly, the plant kingdom can also produce EV-like nanovesicles that can easily be isolated and purified from a large quantity of raw material at a high yield. In this study, olive-derived nanovesicles (ODNVs) were isolated from raw fruits using serial centrifugations and their physical and biological features characterized to demonstrate their promising potential to be used as a DDS. Nanotracking particle analysis indicated an average size of 109.5 ± 3.0 nm and yield of 1012 ODNVs/mL for the purest fraction. Microscopy imaging, membrane fluidity assay and lipidomics analysis showed the presence of a rich lipid bilayer that significantly varied between different sources of ODNVs but showed a distinct signature compared to human EVs. Moreover, ODNVs were enriched in PEN1 and TET8 compared to raw fruits, suggesting an extracellular origin. Interestingly, ODNVs size and yield stayed unchanged after exposure to high temperature (70 °C for 1 h), wide pH range (5-10), and 50-100 nm extrusion, demonstrating high resistance to physical and chemical stresses. This high resistance allowed ODNVs to stay stable in water at 4 °C for a month, or with the addition of 25 mM trehalose for long-term freezing storage. Finally, ODNVs were internalized by both 2D and 3D cell culture without triggering significant cytotoxicity and immunogenicity. Importantly, the anticancer drug doxorubicin (dox) could be loaded by passive incubation within ODNVs and dox-loaded ODNVs decreased cell viability by 90% compared to only 70% for free dox at the same concentration, indicating a higher efficiency of drug delivery by ODNVs. In addition, this high cytotoxicity effect of dox-loaded ODNVs was shown to be stable after a 2-week storage at 4 °C. Together, these findings suggested that ODNVs represent a promising candidate as drug nanocarrier for various DDS clinical applications, as demonstrated by their biocompatibility, high resistance to stress, good stability in harsh environment, and improvement of anticancer drug efficacy.

Neural stem cell-derived extracellular vesicles purified by monolith chromatography retain stimulatory effect in in vitro scratch assay

BACKGROUND AIMS

Extracellular vesicles (EVs) have gained traction as potential cell-free therapeutic candidates. Development of purification methods that are scalable and robust is a major focus of EV research. Yet there is still little in the literature that evaluates purification methods against potency of the EV product. In the present study, we examined two monolith chromatography methods with a focus on assessing the ability of purified EVs to retain stimulatory effects on fibroblasts to connect scalable purification methods with product outputs.

METHODS

We characterized EVs recovered from CTX0E03 (CTX) neural stem cell-conditioned medium in terms of biomarker distribution, functional capacity and purity. We evaluated the ability of EVs to promote wound closure in an in vitro scratch assay prior to and following two monolith chromatography steps (anion exchange and hydrophobic interaction) to determine whether these options may better serve EV bioprocessing.

RESULTS

EVs from CTX cells were successful in initiating wound repair in a fibroblast scratch assay over 72 h with a single 20-μg dose. EV preparations presented the markers CD9, CD81 and CD63 but also contained culture albumin and DNA as process impurities. EVs recovered by tangential flow filtration could be successfully purified further by both monolith chromatography steps. Post-monolith EV stimulation was conserved.

CONCLUSIONS

The results indicate that monolith chromatography is a viable purification method for EVs derived from cell culture that does not detract from the product's ability to stimulate fibroblasts, suggesting that product functionality is conserved. Further work is needed in developing suitable downstream processes and analytics to achieve clinically relevant purities for injectable biologics.

The two coin sides of bacterial extracellular membrane nanovesicles: atherosclerosis trigger or remedy

Among the numerous driving forces that cause the atherosclerotic cardiovascular disease (ASCVD), pathogenic bacterial extracellular membrane nanovesicles (BEMNs) containing toxins and virulence factors appear to be the key trigger of inflammation and atherogenesis, the major processes involved in the pathogenesis of ASCVD. Since BEMNs are the carriers of nanosized biomolecules to distant sites, they are now being considered as a novel drug delivery system. Nowadays, many therapeutic strategies are used to treat ASCVD. However, the conventional anti-atherosclerotic therapies are not effective enough. This primarily due to the inefficiency of non-targeted drug delivery systems to tissue affected areas, which, in turn, leads to numerous side effects, as well as faulty pharmacokinetics. In this regard, nanomedicine methods using nanoparticles (NPs) as targeted drug delivery vehicles proved to be extremely useful. Bioengineered BEMNs equipped with disease-specific ligand moieties and loaded with corresponding drugs represent a promising tool in nanomedicine, which can be used as a novel drug delivery system for a successful therapy of ASCVD. In this review, we outline the involvement of pathogenic BEMNs in the triggering of ASCVD, the conventional therapeutic strategies for the treatment of ASCVD, and the recent trends in nanomedicine using BEMNs and NPs as a vehicle for targeted drug delivery.

Dual-Barb Microneedle with JAK/STAT Inhibitor-Loaded Nanovesicles Encapsulation for Tendinopathy

Tendon stem/progenitor cells (TSPCs) are crucial for tendon repair, regeneration, and homeostasis. Dysfunction of TSPCs, due to aberrant activation of the Janus kinase/signal transducer and activator of transcription (JAK/STAT) signaling pathway, contributes to tendinopathy. Unfortunately, the effectiveness of conventional subcutaneous injection targeting at suppressing JAK/STAT signaling pathway is limited due to the passive diffusion of drugs away from the injury site. Herein, a novel poly-gamma-glutamic acid (γ-PGA) dual-barb microneedle (MN) path loaded with TSPCs-derived nanovesicles (NVs) containing JAK/STAT inhibitor WP1066 (MN-WP1066-NVs) for tendinopathy treatment is designed. The dual-barb design of the MN ensures firm adhesion to the skin, allowing for sustained and prolonged release of WP1066-NVs, facilitating enhanced TSPCs self-renewal, migration, and stemness in tendinopathy. In vitro and in vivo experiments demonstrate that the degradation of γ-PGA patch tips facilitates the gradual release of WP1066-NVs at the lesion site. This release alleviates inflammation, suppresses extracellular matrix degradation, and restores normal tendon histological structure by inhibiting the JAK/STAT pathway. These findings suggest that the multifunctional dual-barb MN patch offers a novel and effective therapeutic strategy for tendinopathy treatment.

Antibody-displaying extracellular vesicles for targeted cancer therapy

Extracellular vesicles (EVs) function as natural delivery vectors and mediators of biological signals across tissues. Here, by leveraging these functionalities, we show that EVs decorated with an antibody-binding moiety specific for the fragment crystallizable (Fc) domain can be used as a modular delivery system for targeted cancer therapy. The Fc-EVs can be decorated with different types of immunoglobulin G antibody and thus be targeted to virtually any tissue of interest. Following optimization of the engineered EVs by screening Fc-binding and EV-sorting moieties, we show the targeting of EVs to cancer cells displaying the human epidermal receptor 2 or the programmed-death ligand 1, as well as lower tumour burden and extended survival of mice with subcutaneous melanoma tumours when systemically injected with EVs displaying an antibody for the programmed-death ligand 1 and loaded with the chemotherapeutic doxorubicin. EVs with Fc-binding domains may be adapted to display other Fc-fused proteins, bispecific antibodies and antibody-drug conjugates.

The Nature and Nurture of Extracellular Vesicle-Mediated Signaling

In the last decade, it has become clear that extracellular vesicles (EVs) are a ubiquitous component of living systems. These small membrane-enclosed particles can confer diverse functions to the cells that release, capture, or coexist with them in an environment. We use examples across living systems to produce a conceptual framework that classifies three modes by which EVs exert functions: (a) EV release that serves a function for producing cells, (b) EV modification of the extracellular environment, and (c) EV interactions with, and alteration of, receiving cells. We provide an overview of the inherent properties of EVs (i.e., their nature) as well as factors in the environment and receiving cell (i.e., nurture) that determine whether transmission of EV cargo leads to functional cellular responses. This review broadens the context for ruminating on EV functions and highlights the emergent properties of EVs that define their role in biology and will shape their applications in medicine.

The Evolution of Microfluidic-Based Drug-Loading Techniques for Cells and Their Derivatives

Conventional drug delivery techniques face challenges related to targeting and adverse reactions. Recent years have witnessed significant advancements in nanoparticle-based drug carriers. Nevertheless, concerns persist regarding their safety and insufficient metabolism. Employing cells and their derivatives, such as cell membranes and extracellular vesicles (EVs), as drug carriers effectively addresses the challenges associated with nanoparticle carriers. However, an essential hurdle remains in efficiently loading drugs into these carriers. With the advancement of microfluidic technology and its advantages in precise manipulation at the micro- and nanoscales, as well as minimal sample loss, it has found extensive application in the loading of drugs using cells and their derivatives, thereby fostering the development of drug-loading techniques. This paper outlines the characteristics and benefits of utilizing cells and their derivatives as drug carriers and provides an overview of current drug-loading techniques, particularly those rooted in microfluidic technology. The significant potential for microfluidic technology in targeted disease therapy through drug delivery systems employing cells and their derivatives, is foreseen.

Engineered exosome therapeutics for neurodegenerative diseases

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

Bidirectional modulation of extracellular vesicle-autophagy axis in acute lung injury: Molecular mechanisms and therapeutic implications

Acute lung injury (ALI), a multifactorial pathological condition, manifests through heightened inflammatory responses, compromised lung epithelial-endothelial barrier function, and oxidative stress, potentially culminating in respiratory failure and mortality. This study explores the intricate interplay between two crucial cellular mechanisms-extracellular vesicles (EVs) and autophagy-in the context of ALI pathogenesis and potential therapeutic interventions.EVs, bioactive membrane-bound structures secreted by cells, serve as versatile carriers of molecular cargo, facilitating intercellular communication and significantly influencing disease progression. Concurrently, autophagy, an essential intracellular degradation process, maintains cellular homeostasis and has emerged as a promising therapeutic target in ALI and acute respiratory distress syndrome.Our research unveils a fascinating "EV-Autophagy dual-drive pathway," characterized by reciprocal regulation between these two processes. EVs modulate autophagy activation and inhibition, while autophagy influences EV production, creating a dynamic feedback loop. This study posits that precise manipulation of this pathway could revolutionize ALI treatment strategies.By elucidating the mechanisms underlying this cellular crosstalk, we open new avenues for targeted therapies. The potential for engineered EVs to fine-tune autophagy in ALI treatment is explored, alongside innovative concepts such as EV-based vaccines for ALI prevention and management. This research not only deepens our understanding of ALI pathophysiology but also paves the way for novel, more effective therapeutic approaches in critical care medicine.

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

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

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

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

PlexinA1 (PLXNA1) as a novel scaffold protein for the engineering of extracellular vesicles

Extracellular vesicles (EVs) had been described as a next-generation drug delivery system, due to the compelling evidence that they can facilitate the transfer of a variety of biomolecules between cells. The most frequently used strategy for loading protein cargoes is the endogenous engineering of EVs through genetic fusion of the protein of interest (POI) and scaffold proteins with high EV-sorting ability. However, the lack of scaffold proteins had become a major issue hindering the promotion of this technology. Herein, we proposed novel screening criteria that relax the inclusion requirement of candidate scaffold proteins and eventually identified a new scaffold protein, PLXNA1. The truncated PLXNA1 not only inherits the high EV-sorting ability of its full-length counterpart but also allows the fusion expression of POI in both outer surface and luminal areas, individually or simultaneously. In conclusion, our screening criteria expanded the range of potential scaffold proteins. The identified scaffold protein PLXNA1 showed great potential in developing therapeutic EVs.

The role of microglia in neurological diseases with involvement of extracellular vesicles

As a subset of mononuclear phagocytes in the central nervous system, microglia play a crucial role in immune defense and homeostasis maintenance. Microglia can regulate their states in response to specific signals of health and pathology. Microglia-mediated neuroinflammation is a pathological hallmark of neurodegenerative diseases, neurological damage and neurological tumors, underscoring its key immunoregulatory role in these conditions. Intriguingly, a substantial body of research has indicated that extracellular vesicles can mediate intercellular communication by transporting cargoes from parental cells, a property that is also reflected in microenvironmental signaling networks involving microglia. Based on the microglial characteristics, we briefly outline the biological features of extracellular vesicles and focus on summarizing the integrative role played by microglia in the maintenance of nervous system homeostasis and progression of different neurological diseases. Extracellular vesicles may engage in the homeostasis maintenance and pathological process as a medium of intercellular communication. Here, we aim to provide new insights for further exploration of neurological disease pathogenesis, which may provide theoretical foundations for cell-free therapies.

Exosome-based immunotherapy as an innovative therapeutic approach in melanoma

The malignant form of melanoma is one of the deadliest human cancers that accounts for almost all of the skin tumor-related fatalities in its later stages. Achieving an exhaustive understanding of reliable cancer-specific markers and molecular pathways can provide numerous practical techniques and direct the way toward the development of rational curative medicines to increase the lifespan of patients. Immunotherapy has significantly enhanced the treatment of metastatic and late-stage melanoma, resulting in an incredible increase in positive responses to therapy. Despite the increasing occurrence of melanoma, the median survival rate for patients with advanced, inoperable terminal disease has increased from around six months to almost six years. The current knowledge of the tumor microenvironment (TME) and its interaction with the immune system has resulted in the swift growth of innovative immunotherapy treatments. Exosomes are small extracellular vesicles (EVs), ranging from 30 to 150 nm in size, that the majority of cells released them. Exosomes possess natural advantages such as high compatibility with living organisms and low potential for causing immune reactions, making them practical for delivering therapeutic agents like chemotherapy drugs, nucleic acids, and proteins. This review highlights recent advancements in using exosomes as an approach to providing medications for the treatment of melanoma.

Extracellular vesicles versus lipid nanoparticles for the delivery of nucleic acids

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

Gamma-aminobutyric acid enhances miR-21-5p loading into adipose-derived stem cell extracellular vesicles to alleviate myocardial ischemia-reperfusion injury via TXNIP regulation

BACKGROUND

Myocardial ischemia-reperfusion injury (MIRI) poses a prevalent challenge in current reperfusion therapies, with an absence of efficacious interventions to address the underlying causes.

AIM

To investigate whether the extracellular vesicles (EVs) secreted by adipose mesenchymal stem cells (ADSCs) derived from subcutaneous inguinal adipose tissue (IAT) under γ-aminobutyric acid (GABA) induction (GABA-EVsIAT) demonstrate a more pronounced inhibitory effect on mitochondrial oxidative stress and elucidate the underlying mechanisms.

METHODS

We investigated the potential protective effects of EVs derived from mouse ADSCs pretreated with GABA. We assessed cardiomyocyte injury using terminal deoxynucleotidyl transferase dUTP nick end-labeling and Annexin V/propidium iodide assays. The integrity of cardiomyocyte mitochondria morphology was assessed using electron microscopy across various intervention backgrounds. To explore the functional RNA diversity between EVsIAT and GABA-EVsIAT, we employed microRNA (miR) sequencing. Through a dual-luciferase reporter assay, we confirmed the molecular mechanism by which EVs mediate thioredoxin-interacting protein (TXNIP). Western blotting and immunofluorescence were conducted to determine how TXNIP is involved in mediation of oxidative stress and mitochondrial dysfunction.

RESULTS

Our study demonstrates that, under the influence of GABA, ADSCs exhibit an increased capacity to encapsulate a higher abundance of miR-21-5p within EVs. Consequently, this leads to a more pronounced inhibitory effect on mitochondrial oxidative stress compared to EVs from ADSCs without GABA intervention, ultimately resulting in myocardial protection. On a molecular mechanism level, EVs regulate the expression of TXNIP and mitigating excessive oxidative stress in mitochondria during MIRI process to rescue cardiomyocytes.

CONCLUSION

Administration of GABA leads to the specific loading of miR-21-5p into EVs by ADSCs, thereby regulating the expression of TXNIP. The EVs derived from ADSCs treated with GABA effectively ameliorates mitochondrial oxidative stress and mitigates cardiomyocytes damage in the pathological process of MIRI.

Enhancing precision targeting of ovarian cancer tumor cells in vivo through extracellular vesicle engineering

Extracellular vesicles (EVs) function as natural mediators of intercellular communication, secreted by cells to facilitate cell-cell signaling. Due to their low toxicity, immunogenicity, biodegradability, and potential to encapsulate therapeutic drugs, EVs hold significant therapeutic promise. Nevertheless, their limited targeting ability often diminishes their therapeutic impact. Therefore, enhancing EVs by incorporating targeting units onto their membranes could bolster their targeting capabilities, enabling them to accumulate in specific cells and tissues. In this study, we engineered EVs to fuse ephrin-B2 with the EV membrane protein LAMP2b. This modification aimed to direct the engineered EVs toward the ephrin-B4 receptor expressed on the surface of ovarian cancer cells. The engineered EVs retained their inherent properties, including size, expression of EV membrane proteins, and morphology, upon isolation. In vitro experiments using real-time imaging revealed that EVs engineered with the ephrin-B2 ligand exhibited substantial internalization and uptake by ovarian cancer cells, in stark contrast to native EVs. In vivo, the engineered EVs carrying the ephrin-B2 ligand effectively targeted ovarian cancer cells, surpassing the targeting efficiency of control EVs. This innovative approach establishes a novel targeting system, enhancing the uptake of EVs by ovarian cancer cells. Our findings underscore the potential of using EVs to target cancer cells, thereby enhancing the effectiveness of anti-cancer therapies while minimizing off-target effects and toxicity in normal cells and organs.

Engineering Approaches for Exosome Cargo Loading and Targeted Delivery: Biological versus Chemical Perspectives

Exosomes are nanoscale membrane bound vesicles secreted by almost all types of cells. Their unique attributes, such as minimal immunogenicity and compatibility with biological systems, make them novel carriers for drug delivery. These native exosomes harbor proteins, nucleic acids, small molecule compounds, and fluorogenic agents. Moreover, through a combination of chemical and bioengineering methodologies, exosomes are tailored to transport precise therapeutic payloads to designated cells or tissues. In this review, we summarize the strategies for exosome modification and drug loading modalities in engineered exosomes. In addition, we provide an overview of the advances in the use of engineered exosomes for targeted drug delivery. Lastly, we discuss the merits and limitations of chemically engineered versus bioengineered exosome-mediated target therapies. These insights offer additional options for refining engineered exosomes in pharmaceutical development and hold promise for expediting the successful translation of engineered exosomes from the bench to the bedside.

Engineered microparticles modulate arginine metabolism to repolarize tumor-associated macrophages for refractory colorectal cancer treatment

BACKGROUND

Arginase is abundantly expressed in colorectal cancer and disrupts arginine metabolism, promoting the formation of an immunosuppressive tumor microenvironment. This significant factor contributes to the insensitivity of colorectal cancer to immunotherapy. Tumor-associated macrophages (TAMs) are major immune cells in this environment, and aberrant arginine metabolism in tumor tissues induces TAM polarization toward M2-like macrophages. The natural compound piceatannol 3'-O-glucoside inhibits arginase activity and activates nitric oxide synthase, thereby reducing M2-like macrophages while promoting M1-like macrophage polarization.

METHODS

The natural compounds piceatannol 3'-O-glucoside and indocyanine green were encapsulated within microparticles derived from tumor cells, termed PG/ICG@MPs. The enhanced cancer therapeutic effect of PG/ICG@MP was assessed both in vitro and in vivo.

RESULTS

PG/ICG@MP precisely targets the tumor site, with piceatannol 3'-O-glucoside concurrently inhibiting arginase activity and activating nitric oxide synthase. This process promotes increased endogenous nitric oxide production through arginine metabolism. The combined actions of nitric oxide and piceatannol 3'-O-glucoside facilitate the repolarization of tumor-associated macrophages toward the M1 phenotype. Furthermore, the increase in endogenous nitric oxide levels, in conjunction with the photodynamic effect induced by indocyanine green, increases the quantity of reactive oxygen species. This dual effect not only enhances tumor immunity but also exerts remarkable inhibitory effects on tumors.

CONCLUSION

Our research results demonstrate the excellent tumor-targeting effect of PG/ICG@MPs. By modulating arginine metabolism to improve the tumor immune microenvironment, we provide an effective approach with clinical translational significance for combined cancer therapy.

Evolving understanding of autoimmune mechanisms and new therapeutic strategies of autoimmune disorders

Autoimmune disorders are characterized by aberrant T cell and B cell reactivity to the body's own components, resulting in tissue destruction and organ dysfunction. Autoimmune diseases affect a wide range of people in many parts of the world and have become one of the major concerns in public health. In recent years, there have been substantial progress in our understanding of the epidemiology, risk factors, pathogenesis and mechanisms of autoimmune diseases. Current approved therapeutic interventions for autoimmune diseases are mainly non-specific immunomodulators and may cause broad immunosuppression that leads to serious adverse effects. To overcome the limitations of immunosuppressive drugs in treating autoimmune diseases, precise and target-specific strategies are urgently needed. To date, significant advances have been made in our understanding of the mechanisms of immune tolerance, offering a new avenue for developing antigen-specific immunotherapies for autoimmune diseases. These antigen-specific approaches have shown great potential in various preclinical animal models and recently been evaluated in clinical trials. This review describes the common epidemiology, clinical manifestation and mechanisms of autoimmune diseases, with a focus on typical autoimmune diseases including multiple sclerosis, type 1 diabetes, rheumatoid arthritis, systemic lupus erythematosus, and sjögren's syndrome. We discuss the current therapeutics developed in this field, highlight the recent advances in the use of nanomaterials and mRNA vaccine techniques to induce antigen-specific immune tolerance.

Therapeutic delivery of recombinant glucocerebrosidase enzyme-containing extracellular vesicles to human cells from Gaucher disease patients

BACKGROUND

Gaucher disease (GD) is one of the most common types of lysosomal storage diseases (LSDs) caused by pathogenic variants of lysosomal β-glucocerebrosidase gene (GBA1), resulting in the impairment of Glucocerebrosidase (GCase) enzyme function and the accumulation of a glycolipid substrate, glucosylceramide (GlcCer) within lysosomes. Current therapeutic approaches such as enzyme replacement therapy and substrate reduction therapy cannot fully rescue GD pathologies, especially neurological symptoms. Meanwhile, delivery of lysosomal enzymes to the endocytic compartment of affected human cells is a promising strategy for treating neuropathic LSDs.

RESULT

Here, we describe a novel approach to restore GCase enzyme in cells from neuropathic GD patients by producing extracellular vesicle (EVs)-containing GCase from cells overexpressing GBA1 gene. Lentiviral vectors containing modified GBA1 were introduced into HEK293T cells to produce a stable cell line that provides a sustainable source of functional GCase enzyme. The GBA1-overexpressing cells released EV-containing GCase enzyme, that is capable of entering into and localizing in the endocytic compartment of recipient cells, including THP-1 macrophage, SH-SY5Y neuroblastoma, and macrophages and neurons derived from induced pluripotent stem cells (iPSCs) of neuropathic GD patients. Importantly, the recipient cells exhibit higher GCase enzyme activity.

CONCLUSION

This study presents a promising therapeutic strategy to treat severe types of LSDs. It involves delivering lysosomal enzymes to the endocytic compartment of human cells affected by conditions such as GDs with neurological symptoms, as well as potentially other neurological disorders impacting lysosomes.