Synergistic siRNA Loading of Extracellular Vesicles Enables Functional Delivery into Cells

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.

Immune cell-derived extracellular vesicles for precision therapy of inflammatory-related diseases

Inflammation-related diseases impose a significant global health burden, necessitating urgent exploration of novel treatment modalities for improved clinical outcomes. We begin by discussing the limitations of conventional approaches and underscore the pivotal involvement of immune cells in the inflammatory process. Amidst the rapid growth of immunology, the therapeutic potential of immune cell-derived extracellular vesicles (EVs) has garnered substantial attention due to their capacity to modulate inflammatory response. We provide an in-depth examination of immune cell-derived EVs, delineating their promising roles across diverse disease conditions in both preclinical and clinical settings. Additionally, to direct the development of the next-generation drug delivery systems, we comprehensively investigate the engineered EVs on their advanced isolation methods, cargo loading techniques, and innovative engineering strategies. This review ends with a focus on the prevailing challenges and considerations regarding the clinical translation of EVs in future, emphasizing the need of standardized characterization and scalable production processes. Ultimately, immune cell-derived EVs represent a cutting-edge therapeutic approach and delivery platform, holding immense promise in precision medicine.

Engineered extracellular vesicles: A new approach for targeted therapy of tumors and overcoming drug resistance

Targeted delivery of anti-tumor drugs and overcoming drug resistance in malignant tumor cells remain significant clinical challenges. However, there are only few effective methods to address these issues. Extracellular vesicles (EVs), actively secreted by cells, play a crucial role in intercellular information transmission and cargo transportation. Recent studies have demonstrated that engineered EVs can serve as drug delivery carriers and showed promising application prospects. Nevertheless, there is an urgent need for further improvements in the isolation and purification of EVs, surface modification techniques, drug assembly processes, and precise recognition of tumor cells for targeted drug delivery purposes. In this review, we summarize the applications of engineered EVs in cancer treatment and overcoming drug resistance, and current challenges associated with engineered EVs are also discussed. This review aims to provide new insights and potential directions for utilizing engineered EVs as targeted delivery systems for anti-tumor drugs and overcoming drug resistance in the near future.

Cell Membrane-Camouflaged Nanoparticles Mediated Nucleic Acids Delivery

Nucleic acids have emerged as promising therapeutic agents for many diseases because of their potential in modulating gene expression. However, the delivery of nucleic acids remains a significant challenge in gene therapy. Although viral vectors have shown high transfection efficiency, concerns regarding teratogenicity or carcinogenicity have been raised. Non-viral vehicles, including cationic polymers, liposomes, and inorganic materials possess advantages in terms of safety, ease of preparation, and low cost. Nevertheless, they also face limitations related to immunogenicity, quick clearance in vivo, and lack of targeting specificity. On the other hand, bioinspired strategies have shown increasing potential in the field of drug delivery, yet there is a lack of comprehensive reviews summarizing the rapid development of bioinspired nanoparticles based on the cell membrane camouflage to construct the nucleic acids vehicles. Herein, we enumerated the current difficulties in nucleic acid delivery with various non-viral vehicles and provided an overview of bioinspired strategies for nucleic acid delivery.

CRISPR-Cas9 delivery strategies with engineered extracellular vesicles

Therapeutic genome editing has the potential to cure diseases by directly correcting genetic mutations in tissues and cells. Recent progress in the CRISPR-Cas9 systems has led to breakthroughs in gene editing tools because of its high orthogonality, versatility, and efficiency. However, its safe and effective administration to target organs in patients is a major hurdle. Extracellular vesicles (EVs) are endogenous membranous particles secreted spontaneously by all cells. They are key actors in cell-to-cell communication, allowing the exchange of select molecules such as proteins, lipids, and RNAs to induce functional changes in the recipient cells. Recently, EVs have displayed their potential for trafficking the CRISPR-Cas9 system during or after their formation. In this review, we highlight recent developments in EV loading, surface functionalization, and strategies for increasing the efficiency of delivering CRISPR-Cas9 to tissues, organs, and cells for eventual use in gene therapies.

Preparation of Nanosized Pharmaceutical Formulations by Dual Centrifugation

Dual centrifugation (DC) is an innovative in-vial homogenization and in-vial nanomilling technique that has been in use for the preparation of liposomes for more than one decade. Since then, DC has continuously been developed for preparing various liposomes and other lipid nanoparticles including emulsions and solid lipid nanoparticles (SLNs) as well as polymersomes and nanocrystals. Improvements in equipment technology have been achieved over the past decade, so that DC is now on its way to becoming the quasi-standard for the simple, fast, and aseptic production of lipid nanoparticles and nanocrystals in small and medium batch sizes, including the possibility of simple and fast formulation screening or bedside preparations of therapeutic nanoparticles. More than 68 publications in which DC was used to produce nanoparticles have appeared since then, justifying an initial review of the use of DC for pharmaceutical nanotechnology.

Standardization Approaches for Extracellular Vesicle Loading with Oligonucleotides and Biologics

Extracellular vesicles (EVs) are widely recognized for their potential as drug delivery systems. EVs are membranous nanoparticles shed from cells. Among their natural features are their ability to shield cargo molecules against degradation and enable their functional internalization into target cells. Especially biological or bio-inspired large molecules (LMs), like nucleic acids, proteins, peptides, and others, may profit from encapsulation in EVs for drug delivery purposes. In the last years, a variety of loading protocols are explored for different LMs. The lack of standardization in the EV drug delivery field has impeded their comparability so far. Currently, the first reporting frameworks and workflows for EV drug loading are proposed. The aim of this review is to summarize these evolving standardization approaches and set recently developed methods into context. This will allow for enhanced comparability of future work on EV drug loading with LMs.

Macrophage Membrane-Reversibly Cloaked Nanotherapeutics for the Anti-Inflammatory and Antioxidant Treatment of Rheumatoid Arthritis

During rheumatoid arthritis (RA) development, over-produced proinflammatory cytokines represented by tumor necrosis factor-α (TNF-α) and reactive oxygen species (ROS) represented by H2 O2 form a self-promoted cycle to exacerbate the synovial inflammation and tissue damage. Herein, biomimetic nanocomplexes (NCs) reversibly cloaked with macrophage membrane (RM) are developed for effective RA management via dual scavenging of TNF-α and ROS. To construct the NCs, membrane-penetrating, helical polypeptide first condenses TNF-α siRNA (siTNF-α) and forms the cationic inner core, which further adsorbs catalase (CAT) via electrostatic interaction followed by surface coating with RM. The membrane-coated NCs enable prolonged blood circulation and active joint accumulation after systemic administration in Zymosan A-induced arthritis mice. In the oxidative microenvironment of joints, CAT degrades H2 O2 to produce O2 bubbles, which shed off the outer membrane layer to expose the positively charged inner core, thus facilitating effective intracellular delivery into macrophages. siRNA-mediated TNF-α silencing and CAT-mediated H2 O2 scavenging then cooperate to inhibit inflammation and alleviate oxidative stress, remodeling the osteomicroenvironment and fostering tissue repair. This study provides an enlightened strategy to resolve the blood circulation/cell internalization dilemma of cell membrane-coated nanosystems, and it renders a promising modality for RA treatment.

siRNA Delivery against Myocardial Ischemia Reperfusion Injury Mediated by Reversibly Camouflaged Biomimetic Nanocomplexes

siRNA-mediated management of myocardial ischemia reperfusion (IR) injury is greatly hampered by the inefficient myocardial enrichment and cardiomyocyte transfection. Herein, nanocomplexes (NCs) reversibly camouflaged with a platelet-macrophage hybrid membrane (HM) are developed to efficiently deliver Sav1 siRNA (siSav1) into cardiomyocytes, suppressing the Hippo pathway and inducing cardiomyocyte regeneration. The biomimetic BSPC@HM NCs consist of a cationic nanocore assembled from a membrane-penetrating helical polypeptide (P-Ben) and siSav1, a charge-reversal intermediate layer of poly(l-lysine)-cis-aconitic acid (PC), and an outer shell of HM. Due to HM-mediated inflammation homing and microthrombus targeting, intravenously injected BSPC@HM NCs can efficiently accumulate in the IR-injured myocardium, where the acidic inflammatory microenvironment triggers charge reversal of PC to shed off both HM and PC layers and allow the penetration of the exposed P-Ben/siSav1 NCs into cardiomyocytes. In rats and pigs, BSPC@HM NCs remarkably downregulates Sav1 in IR-injured myocardium, promotes myocardium regeneration, suppresses myocardial apoptosis, and recovers cardiac functions. This study reports a bioinspired strategy to overcome the multiple systemic barriers against myocardial siRNA delivery, and holds profound potential for gene therapy against cardiac injuries.

Extracellular vesicles as a novel approach for breast cancer therapeutics

Breast cancer (BC) still lacks effective management approaches to control metastatic and therapy-resistant disease. Extracellular vesicles (EVs), with a diameter of 50-1000 nm, are secreted by all types of living cells, are protected by a lipid bilayer and encapsulate biological cargos including RNAs, proteins and lipids. They play an important role in intercellular communications and are significantly associated with pathological conditions. Accumulating evidence indicates that cancer cells secrete EVs and communicate with neighboring cells within the tumor microenvironment (TME), which plays an important role in BC metastasis, immune escape and chemoresistance, thus providing a new therapeutic window. EVs can stimulate angiogenesis and extracellular matrix remodeling, establish premetastatic niches, inhibit immune response and promote cancer metastasis. Recent advances have demonstrated that EVs are a potential therapeutic target or carrier and have emerged as promising strategies for BC treatment. In this review, we summarize the role of EVs in BC metastasis, chemoresistance and immune escape, which provides the foundation for developing novel therapeutic approaches. We also focus on current EV-based drug delivery strategies in BC and EV cargo-targeted BC therapy and discuss the limitations and future perspectives of EV-based drug delivery in BC.

Extracellular Vesicle-Based SARS-CoV-2 Vaccine

Messenger ribonucleic acid (RNA) vaccines are mainly used as SARS-CoV-2 vaccines. Despite several issues concerning storage, stability, effective period, and side effects, viral vector vaccines are widely used for the prevention and treatment of various diseases. Recently, viral vector-encapsulated extracellular vesicles (EVs) have been suggested as useful tools, owing to their safety and ability to escape from neutral antibodies. Herein, we summarize the possible cellular mechanisms underlying EV-based SARS-CoV-2 vaccines.