Nebulization of extracellular vesicles: A promising small RNA delivery approach for lung diseases

Nebulized inhalation of extracellular vesicles containing SPOCK2 suppresses lung adenocarcinoma progression via MAPK inhibition

Aberrant expression of SPARC/osteonectin, cwcv and kazal-like domains proteoglycan 2 (SPOCK2) plays a role in the development and progression of several human cancers. However, the importance of its expression and function in lung adenocarcinoma (LUAD) remains unclear. The present study aimed to elucidate the role of SPOCK2 in the growth of LUAD and propose a novel therapeutic insight for LUAD through SPOCK2. SPOCK2 protein expression was significantly reduced in LUAD tissues and cells by Immunohistochemical assay and Western blot. CCK-8, colony formation, and Transwell assays were used to demonstrate that SPOCK2 overexpression inhibited both proliferation and migration of LUAD cells in vitro. This inhibition of tumor growth was further confirmed by a LUAD xenograft mouse model in vivo. To explore downstream target signal of SPOCK2 in LUAD, RNA transcriptome sequencing was performed and enrichment analysis showed an association between SPOCK2 expression and the MAPK pathway. Furthermore, HEK293T cells were modified with SPOCK2, and extracellular vesicles (EVs) containing SPOCK2 (SPOCK2-EVs) were collected through ultra-high-speed centrifugation. Interestingly, co-culture with SPOCK2-EVs significantly increased SPOCK2 levels within LUAD cells. Furthermore, SPOCK2-EVs effectively inhibited LUAD growth in vitro and in vivo studies. Because directly injecting SPOCK2-EVs into tumors presents challenges for internal organs, we investigated the efficacy of nebulized SPOCK2-EVs for LUAD treatment. Consistent with our findings from intratumoral injection, nebulized inhalation of SPOCK2-EVs resulted in significant inhibition of LUAD growth. These results strongly suggest that SPOCK2 released by HEK293T-EVs can effectively inhibit LUAD tumor growth and hold promise for future clinical translation in cancer therapy.

Inhalable pH-responsive charge-reversal polymer-small interfering RNA polyplexes for directed gene therapy of anaplastic lymphoma kinase fusion-positive lung cancer

Anaplastic lymphoma kinase (ALK) oncogenic fusions are an infamously evolving target in ALK fusion-positive (ALK+) non-small cell lung cancer (NSCLC). RNA interference (RNAi) is a potential alternative to small-molecule ALK inhibitors but suffers from poor cellular delivery and low stability, restricting sustained on-target therapeutic efficacy. To attain non-invasive direct RNAi at target sites in the lungs, inhalable vehicles are demanded to shield unstable siRNA from degradation in alkaline pleural fluid and to shuttle siRNA in the acidic tumor microenvironment. Here, we chemically synthesize a universal polyethylene glycol-poly(β-amino esters)-histidine(PEG-PBAE-His, PPH) system that enables siRNA-directed ALK gene silencing in ALK+ NSCLC with controlled release. The rational design of PEGylated polycationic PPH integrates the non-ionic nature, inertness, stealth effect, and low immunogenicity of PEG coronae with dual positively-charged PBAE and His to encapsulate siRNA payloads through enhanced electrostatic complexations. The assembled polyplexes with low polydispersity are overall anionic in alkaline pleural fluid and reversed into cationic charges at acidic pH, facilitating cellular uptake and lysosomal pH-governed release. The PPH-directed delivery significantly improves siRNA stability and ALK sequence-specific knockdown in H3122 cells, with a transfection efficiency comparable to commercial polyethylenimine but with lower cytotoxicity. The ALK-centric RNAi therapy prohibits cancer clonogenicity, migration, and invasion and induces potent growth inhibition in ALK+ NSCLC xenografts through inhalation. The inhalable polyplexes represent a transformative delivery platform that combines pH-responsive targeting, enhanced stability, and low toxicity, addressing critical limitations of existing siRNA delivery systems.

Engineering Extracellular Vesicles Derived from 3D Cultivation of BMSCs Enriched with HGF Ameliorate Sepsis-Induced Lung Epithelial Barrier Damage

Sepsis is a critical condition with high mortality, often leading to acute lung injury (ALI) due to uncontrolled inflammatory responses and alveolar epithelial damage. Extracellular vesicles (EVs), particularly mesenchymal stem cell-derived EVs, have shown therapeutic potential in sepsis-related organ dysfunction by transferring RNAs and proteins. However, their clinical use is limited by low efficacy and yield. To address this, 3D-cultured MSCs (3D-MSCs) are generated using MicroTissues 3D Petri Dish. These 3D-MSCs demonstrate improved protection and proliferation of MLE-12 cells in vitro. Mechanistic studies are conducted to explore the enhanced protective effects of 3D-MSCs derived EVs (3D-EVs) in a septic-ALI model. Proteomic and molecular analyses of 3D-EVs revealed that they are enriched in hepatocyte growth factor (HGF). HGF helps maintain the barrier function of damaged alveolar epithelium through the PI3K-AKT signaling pathway. Overall, 3D-EVs effectively ameliorate sepsis-induced ALI and enhance prognosis by enriching and delivering HGF, suggesting that their application represents a promising treatment strategy for septic ALI.

Extracellular vesicles derived from mesenchymal stem cells ameliorate sulfur mustard-induced lung injury by regulating apoptosis via miR-146a-5p

Sulfur mustard (SM) is an extremely toxic chemical warfare agent. Although SM-induced toxicity has long been studied, due to its complexity, the characterization of the precise molecular pathway it targets has been remaining an ongoing area of research. Extracellular vesicles derived from human umbilical cord mesenchymal stem cells (hucMSC-EVs) are natural substances that participate in intercellular communication by delivering microRNA to target cells. Importantly, the microRNA content in EVs can be modified. MiR-146a-5p delivered by EVs were utilized and hucMSCs were further modified with miR-146a-5p mimics or inhibitors to collect EVs that over-(miR-146a-5p+-EVs) or underexpress (miR-146a-5p--EVs) miR-146a-5p. Transcriptome sequencing was used to identify potential mediators of the effects of miR-146a-5p delivered by hucMSC-EVs. Our results showed that hucMSC-EVs reduced SM-induced lung injury by mitigating apoptosis. These effects were enhanced by miR-146a-5p+-EVs and weakened by miR-146a-5p--EVs. Meanwhile, the relationship between apoptosis enhancing nuclease (AEN) and miR-146a-5p was discovered, a novel target of miR-146a-5p. Our study showed that hucMSC-EVs ameliorating sulfur mustard induced lung injury through miR-146a-5p, and AEN was one of the functional molecules in this process.

The (re)emergence of aerosol delivery: Treatment of pulmonary diseases and its clinical challenges

Aerosol delivery represents a rapid and non-invasive way to directly reach the lungs while escaping the hepatic first-pass effect. The development of pulmonary drugs for respiratory diseases such as cystic fibrosis, lung infections, pulmonary fibrosis or lung cancer requires an enhanced understanding of the relationships between the natural physiology of the respiratory system and the pathophysiology of these conditions. This knowledge is crucial to better predict and thereby control drug deposition. Moreover, aerosol administration faces several challenges, including the pulmonary tract, immune system, mucociliary clearance, the presence of fluid on the airway surfaces, and, in some cases, bacterial colonisation. Each of them directly influences on the bioavailability of the active molecule. In addition to these challenges, particle size and the device used to administer the treatment are critical factors that can significantly impact the biodistribution of the drugs. Nanoparticles are very promising in the development of new formulations for aerosol drug delivery, as they can be fine-tuned to reach the entire pulmonary tract and overcome the difficulties encountered along the way. However, to properly assess drug delivery, preclinical studies need to be more thorough to efficiently enhance drug delivery.

Engineered extracellular vesicles: an emerging nanomedicine therapeutic platform

The intercellular communication role of extracellular vesicles has been widely proved in various organisms. Compelling evidence has illustrated the involvement of these vesicles in both physiological and pathological processes. Various studies indicate that extracellular vesicles surpass conventional synthetic drug carriers, owing to their abundance in organisms, enhanced targeting ability and low immunogenicity. Therefore, extracellular vesicles have been deemed to be potential drug carriers for the treatment of various diseases, and related studies have increased rapidly. Here, we intend to provide a comprehensive and in-depth review of recent advances in the sources, delivery function, extraction and cargo-loading technologies of extracellular vesicles, as well as their clinical potential in constructing emerging nanomedicine therapeutic platforms. In particular, microfluidic-based isolation and drug-loading technologies, as well as the treatment of various diseases, are highlighted. We also make comparisons between extracellular vesicles and other conventional drug carriers and discuss the challenges in developing drug delivery platforms for clinical translation.

Nebulized mesenchymal stem cell-derived exosomes attenuate airway inflammation in a rat model of chronic obstructive pulmonary disease

Chronic Obstructive Pulmonary Disease (COPD) is one of the leading causes of death worldwide, and current treatments fail to significantly halt its progression. Exosomes derived from mesenchymal stem cells (MSCs-Exos) have demonstrated promising potential in treating COPD due to their anti-inflammatory and regenerative biological properties. In this study, we investigated the potential anti-inflammatory effects of bone marrow mesenchymal stem cell-derived exosomes (BMSCs-Exos) in a COPD rat model and the possible mechanisms by which they inhibit airway remodeling, as well as identifying the optimal dosage and administration route. Our results show that nebulized BMSC-Exos significantly improve lung function in COPD rats while reducing pulmonary inflammatory infiltration, bronchial mucus secretion, and collagen deposition. Moreover, BMSC-Exos treatment notably decreased the expression of pro-inflammatory cytokines such as TNF-α, IL-6 and IL-1β, and the pro-fibrotic factor TGF-β1 in serum, bronchoalveolar lavage fluid (BALF), and lung tissue. The most pronounced therapeutic effect was observed at a low dose of exosomes. Furthermore, quantitative real-time PCR and immunohistochemical analyses revealed that nebulized BMSC-Exos significantly inhibited airway remodeling and epithelial-mesenchymal transition (EMT) by suppressing the Wnt/β-catenin signaling pathway. In conclusion, these findings indicate that nebulized BMSC-Exos offer a noninvasive therapeutic strategy for COPD by mitigating lung inflammation and airway remodeling through the suppression of abnormal Wnt/β-catenin pathway activation induced by cigarette smoke (CS) and lipopolysaccharide (LPS) in rats.

Ultrasonic Microfluidic Method Used for siHSP47 Loaded in Human Embryonic Kidney Cell-Derived Exosomes for Inhibiting TGF-β1 Induced Fibroblast Differentiation and Migration

Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive, and devastating lung disorder. In response to transforming growth factor-β (TGF-β), normal lung cells proliferate and differentiate into myofibroblasts, which are instrumental in promoting disease progression. Small interfering RNA (siRNA) targeting heat shock protein 47 (HSP47) has been demonstrated to alleviate IPF by blocking collagen synthesis and secretion. Exosomes (EXOs) have been investigated for drug delivery due to their superior carrier properties. However, their loading efficiency has been a limiting factor in widely application as drug carriers. In this study, an ultrasonic microfluidic method was employed to enhance the loading efficiency of siHSP47 into EXOs, achieving 31.1% efficiency rate. EXOs were isolated from human embryonic kidney cells (293F) and loaded with siHSP47 (EXO-siHSP47). The findings indicated that EXO-siHSP47 penetrated the collagen barrier and effectively silenced HSP47 expression in activated fibroblasts in vitro. Western blotting and immunofluorescence analyses confirmed that EXO-siHSP47 significantly reduced the secretion and deposition of extracellular matrix (ECM) proteins. Wound healing and Transwell migration assays demonstrated that EXO-siHSP47 inhibited fibroblast differentiation and migration. In conclusion, 293F-derived EXOs loaded with siHSP47 present a promising therapeutic strategy for IPF.

The impact of circulating nucleosomes on inflammation in acute lung injury

Extracellular histones are released in two major forms: free histones and nucleosomes (DNA-bound histones). However, little distinction has been made between these two forms of circulating extracellular histones. Our study detected increased circulating nucleosomes in acute lung injury patients. Further, our group identified nucleosomes as the leading form of extracellular histones compared to free histones in the plasma of COVID-19 patients, underscoring the necessity to reassess the forms of circulating histones and nucleosome contributions to immunopathology. Functionally, nucleosomes activated macrophages and induced inflammation in different organs. Mechanistically, we observed nucleosomes activating the NF-κB signaling, while inhibition of NF-κB by sulfasalazine attenuated nucleosome-induced macrophage activation. Taken together, our study indicates that extracellular histones are predominantly released as nucleosomes, playing a critical role in the inflammation of the lungs and other organs.

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.

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.

Extracellular Vesicles: Diagnostic and Therapeutic Applications in Cancer

In recent years, knowledge of cell-released extracellular vesicle (EV) functions has undergone rapid growth. EVs are membrane vesicles loaded with proteins, nucleic acids, lipids, and bioactive molecules. Once released into the extracellular space, EVs are delivered to target cells that may go through modifications in physiological or pathological conditions. EVs are nano shuttles with a crucial role in promoting short- and long-distance cell-cell communication. Comprehension of the mechanism that regulates this process is a benefit for both medicine and basic science. Currently, EVs attract immense interest in precision and nanomedicine for their potential use in diagnosis, prognosis, and therapies. This review reports the latest advances in EV studies, focusing on the nature and features of EVs and on conventional and emerging methodologies used for their separation, characterization, and visualization. By searching an extended portion of the relevant literature, this work aims to give a summary of advances in nanomedical applications of EVs. Moreover, concerns that require further studies before translation to clinical applications are discussed.

Pulmonary delivery of cell membrane-derived nanovesicles carrying anti-miRNA155 oligonucleotides ameliorates LPS-induced acute lung injury

Acute lung injury (ALI) is a devastating inflammatory disease. MicroRNA155 (miR155) in alveolar macrophages and lung epithelial cells enhances inflammatory reactions by inhibiting the suppressor of cytokine signaling 1 (SOCS1) in ALI. Anti-miR155 oligonucleotide (AMO155) have been suggested as a potential therapeutic reagent for ALI. However, a safe and efficient carrier is required for delivery of AMO155 into the lungs for ALI therapy. In this study, cell membrane-derived nanovesicles (CMNVs) were produced from cell membranes of LA4 mouse lung epithelial cells and evaluated as a carrier of AMO155 into the lungs. For preparation of CMNVs, cell membranes were isolated from LA4 cells and CMNVs were produced by extrusion. Cholesterol-conjugated AMO155 (AMO155c) was loaded into CMNVs and extracellular vesicles (EVs) by sonication. The physical characterization indicated that CMNVs with AMO155c (AMO155c/CMNV) were membrane-structured vesicles with a size of ∼120 nm. The delivery efficiency and therapeutic efficacy of CMNVs were compared with those of EVs or polyethylenimine (25 kDa, PEI25k). The delivery efficiency of AMO155c by CMNVs was similar to that by EVs. As a result, the miR155 levels were reduced by AMO155c/CMNV and AMO155c/EV. AMO155c/CMNV were administered intratracheally into the ALI models. The SOCS1 levels were increased more efficiently by AMO155c/CMNV than by the others, suggesting that miR155 effectively was inhibited by AMO155c/CMNV. In addition, the inflammatory cytokines were reduced more effectively by AMO155c/CMNV than they were by AMO155c/EV and AMO155c/PEI25k, reducing inflammation reactions. The results suggest that CMNVs are a useful carrier of AMO155c in the treatment of ALI.

From mesenchymal stem cells to their extracellular vesicles: Progress and prospects for asthma therapy

Asthma is a widespread public health concern, with an increasing incidence. Despite the implementation of current treatment strategies, asthma control, particularly for severe cases, remains suboptimal. Recent research has revealed the encouraging prospects of extracellular vesicles (EVs) secreted by mesenchymal stem cells (MSCs) as a viable therapeutic option for alleviating asthma symptoms. Therefore, the present review aims to provide an overview of the current progress and the therapeutic mechanisms of using MSC-derived EVs (MSC-EVs) for asthma treatment. Additionally, different administration approaches for EVs and their impacts on biodistribution and the curative outcomes of EVs are summarized. Notably, the potential benefits of nebulized inhalation of MSC-EVs are addressed. Also, the possibilities and challenges of using MSC-EVs for asthma treatment in clinics are highlighted. Overall, this review is intended to give new insight into the utilization of MSC-EVs as a potential biological drug for asthma treatment.

Nebulized milk exosomes loaded with siTGF-β1 ameliorate pulmonary fibrosis by inhibiting EMT pathway and enhancing collagen permeability

Pulmonary Fibrosis (PF) is a fatal disease in the interstitial lung associated with high mortality, morbidity, and poor prognosis. Transforming growth factor-β1 (TGF-β1) is a fibroblast-activating protein that promotes fibrous diseases. Herein, an inhalable system was first developed using milk exosomes (M-Exos) encapsulating siRNA against TGF-β1 (MsiTGF-β1), and their therapeutic potential for bleomycin (BLM)-induced PF was investigated. M-siTGF-β1 was introduced into the lungs of mice with PF through nebulization. The collagen penetration effect and lysosomal escape ability were verified in vitro. Inhaled MsiTGF-β1 notably alleviated inflammatory infiltration, attenuated extracellular matrix (ECM) deposition, and increased the survival rate of PF mice by 4.7-fold. M-siTGF-β1 protected lung tissue from BLM toxicity by efficiently delivering specific siRNA to the lungs, leading to TGF-β1 mRNA silencing and epithelial mesenchymal transition pathway inhibition. Therefore, M-siTGF-β1 offers a promising avenue for therapeutic intervention in fibrosis-related disorders.

Nebulized platelet-derived extracellular vesicles attenuate chronic cigarette smoke-induced murine emphysema

Chronic obstructive pulmonary disease (COPD) is a prevalent lung disease usually resulting from cigarette smoking (CS). Cigarette smoking induces oxidative stress, which causes inflammation and alveolar epithelial cell apoptosis and represents a compelling therapeutic target for COPD. Purified human platelet-derived exosome product (PEP) is endowed with antioxidant enzymes and immunomodulatory molecules that mediate tissue repair. In this study, a murine model of CS-induced emphysema was used to determine whether nebulized PEP can influence the development of CS-induced emphysema through the mitigation of oxidative stress and inflammation in the lung. Nebulization of PEP effectively delivered the PEP vesicles into the alveolar region, with evidence of their uptake by type I and type II alveolar epithelial cells and macrophages. Lung function testing and morphometric assessment showed a significant attenuation of CS-induced emphysema in mice treated with nebulized PEP thrice weekly for 4 weeks. Whole lung immuno-oncology RNA sequencing analysis revealed that PEP suppressed several CS-induced cell injuries and inflammatory pathways. Validation of inflammatory cytokines and apoptotic protein expression on the lung tissue revealed that mice treated with PEP had significantly lower levels of S100A8/A9 expressing macrophages, higher levels of CD4+/FOXP3+ Treg cells, and reduced NF-κB activation, inflammatory cytokine production, and apoptotic proteins expression. Further validation using in vitro cell culture showed that pretreatment of alveolar epithelial cells with PEP significantly attenuated CS extract-induced apoptotic cell death. These data show that nebulization of exosomes like PEP can effectively deliver exosome cargo into the lung, mitigate CS-induced emphysema in mice, and suppress oxidative lung injury, inflammation, and apoptotic alveolar epithelial cell death.

Pulmonary drug delivery devices and nanosystems as potential treatment strategies for acute respiratory distress syndrome (ARDS)

Despite advances in drug delivery technologies, treating acute respiratory distress syndrome (ARDS) is challenging due to pathophysiological barriers such as lung injury, oedema fluid build-up, and lung inflammation. Active pharmaceutical ingredients (API) can be delivered directly to the lung site of action with the use of aerosol-based drug delivery devices, and this circumvents the hepatic first-pass effect and improves the bioavailability of drugs. This review discusses the various challenges and barriers for pulmonary drug delivery, current interventions for delivery, considerations for effective drug delivery, and the use of nanoparticle drug delivery carriers as potential strategies for delivering therapeutics in ARDS. Nanosystems have the added benefit of entrapping drugs, increase pulmonary drug bioavailability, and using biocompatible and biodegradable excipients that can facilitate targeted and/or controlled delivery. These systems provide an alternative to existing conventional systems. An effective way to deliver drugs for the treatment of ARDS can be by using colloidal systems that are aerosolized or inhaled. Drug distribution to the deeper pulmonary tissues is necessary due to the significant endothelial cell destruction that is prevalent in ARDS. The particle size of nanoparticles (<0.5 μm) makes them ideal candidates for treating ARDS as they can reach the alveoli. A look into the various potential benefits and limitations of nanosystems used for other lung disorders is also considered to indicate how they may be useful for the potential treatment of ARDS.

Recent Progress in Nucleic Acid Pulmonary Delivery toward Overcoming Physiological Barriers and Improving Transfection Efficiency

Pulmonary delivery of therapeutic agents has been considered the desirable administration route for local lung disease treatment. As the latest generation of therapeutic agents, nucleic acid has been gradually developed as gene therapy for local diseases such as asthma, chronic obstructive pulmonary diseases, and lung fibrosis. The features of nucleic acid, specific physiological structure, and pathophysiological barriers of the respiratory tract have strongly affected the delivery efficiency and pulmonary bioavailability of nucleic acid, directly related to the treatment outcomes. The development of pharmaceutics and material science provides the potential for highly effective pulmonary medicine delivery. In this review, the key factors and barriers are first introduced that affect the pulmonary delivery and bioavailability of nucleic acids. The advanced inhaled materials for nucleic acid delivery are further summarized. The recent progress of platform designs for improving the pulmonary delivery efficiency of nucleic acids and their therapeutic outcomes have been systematically analyzed, with the application and the perspectives of advanced vectors for pulmonary gene delivery.

Applications and advancements of nanoparticle-based drug delivery in alleviating lung cancer and chronic obstructive pulmonary disease

Lung cancer (LC) and chronic obstructive pulmonary disease (COPD) are among the leading causes of mortality worldwide. Cigarette smoking is among the main aetiologic factors for both ailments. These diseases share common pathogenetic mechanisms including inflammation, oxidative stress, and tissue remodelling. Current therapeutic approaches are limited by low efficacy and adverse effects. Consequentially, LC has a 5-year survival of < 20%, while COPD is incurable, underlining the necessity for innovative treatment strategies. Two promising emerging classes of therapy against these diseases include plant-derived molecules (phytoceuticals) and nucleic acid-based therapies. The clinical application of both is limited by issues including poor solubility, poor permeability, and, in the case of nucleic acids, susceptibility to enzymatic degradation, large size, and electrostatic charge density. Nanoparticle-based advanced drug delivery systems are currently being explored as flexible systems allowing to overcome these limitations. In this review, an updated summary of the most recent studies using nanoparticle-based advanced drug delivery systems to improve the delivery of nucleic acids and phytoceuticals for the treatment of LC and COPD is provided. This review highlights the enormous relevance of these delivery systems as tools that are set to facilitate the clinical application of novel categories of therapeutics with poor pharmacokinetic properties.

Recent advances in extracellular vesicles for therapeutic cargo delivery

Exosomes, which are nanosized vesicles secreted by cells, are attracting increasing interest in the field of biomedical research due to their unique properties, including biocompatibility, cargo loading capacity, and deep tissue penetration. They serve as natural signaling agents in intercellular communication, and their inherent ability to carry proteins, lipids, and nucleic acids endows them with remarkable therapeutic potential. Thus, exosomes can be exploited for diverse therapeutic applications, including chemotherapy, gene therapy, and photothermal therapy. Moreover, their capacity for homotypic targeting and self-recognition provides opportunities for personalized medicine. Despite their advantages as novel therapeutic agents, there are several challenges in optimizing cargo loading efficiency and structural stability and in defining exosome origins. Future research should include the development of large-scale, quality-controllable production methods, the refinement of drug loading strategies, and extensive in vivo studies and clinical trials. Despite the unresolved difficulties, the use of exosomes as efficient, stable, and safe therapeutic delivery systems is an interesting area in biomedical research. Therefore, this review describes exosomes and summarizes cutting-edge studies published in high-impact journals that have introduced novel or enhanced therapeutic effects using exosomes as a drug delivery system in the past 2 years. We provide an informative overview of the current state of exosome research, highlighting the unique properties and therapeutic applications of exosomes. We also emphasize challenges and future directions, underscoring the importance of addressing key issues in the field. With this review, we encourage researchers to further develop exosome-based drugs for clinical application, as such drugs may be among the most promising next-generation therapeutics.

Opportunities and Challenges for Inhalable Nanomedicine Formulations in Respiratory Diseases: A Review

Lungs experience frequent interactions with the external environment and have an abundant supply of blood; therefore, they are susceptible to invasion by pathogenic microorganisms and tumor cells. However, the limited pharmacokinetics of conventional drugs in the lungs poses a clinical challenge. The emergence of different nano-formulations has been facilitated by advancements in nanotechnology. Inhaled nanomedicines exhibit better targeting and prolonged therapeutic effects. Although nano-formulations have great potential, they still present several unknown risks. Herein, we review the (1) physiological anatomy of the lungs and their biological barriers, (2) pharmacokinetics and toxicology of nanomaterial formulations in the lungs; (3) current nanomaterials that can be applied to the respiratory system and related design strategies, and (4) current applications of inhaled nanomaterials in treating respiratory disorders, vaccine design, and imaging detection based on the characteristics of different nanomaterials. Finally, (5) we analyze and summarize the challenges and prospects of nanomaterials for respiratory disease applications. We believe that nanomaterials, particularly inhaled nano-formulations, have excellent prospects for application in respiratory diseases. However, we emphasize that the simultaneous toxic side effects of biological nanomaterials must be considered during the application of these emerging medicines. This study aims to offer comprehensive guidelines and valuable insights for conducting research on nanomaterials in the domain of the respiratory system.

Inhalable dry powders of microRNA-laden extracellular vesicles prepared by thin-film freeze-drying

Extracellular vesicles (EVs) are endogenous vesicles that comprise a variety of submicron vesicular structures. Among these, exosomes have been widely investigated as delivery systems for small and large molecules. Herein, the thin-film freeze-drying technology was utilized to engineer aerosolizable dry powders of miR-335-laden induced EVs (iEV-335) generated in B cells for potential delivery into the lung to treat primary lung cancer and/or pulmonary metastases. The size distribution, structure, and morphology of iEV-335 were preserved after they were subjected to thin-film freeze-drying with the proper excipients. Importantly, iEV-335, in liquid or reconstituted from thin-film freeze-dried powders, were equally effective in downregulating SOX4 gene expression in LM2 human triple-negative mammary cancer cells. The iEV-335 dry powder compositions showed mass median aerodynamic diameters (MMAD) of around 1.2 µm with > 60 % of the emitted doses had an MMAD of ≤ 3 µm, indicating that the powders can potentially achieve efficient deposition within the alveolar region following oral inhalation, which is desirable for treatment of primary lung cancer and pulmonary metastases. Overall, it is concluded that it is feasible to apply thin-film freeze-drying to prepare aerosolizable dry powders of iEVs for pulmonary delivery.

Nebulised delivery of RNA formulations to the lungs: From aerosol to cytosol

In the past decade RNA-based therapies such as small interfering RNA (siRNA) and messenger RNA (mRNA) have emerged as new and ground-breaking therapeutic agents for the treatment and prevention of many conditions from viral infection to cancer. Most clinically approved RNA therapies are parenterally administered which impacts patient compliance and adds to healthcare costs. Pulmonary administration via inhalation is a non-invasive means to deliver RNA and offers an attractive alternative to injection. Nebulisation is a particularly appealing method due to the capacity to deliver large RNA doses during tidal breathing. In this review, we discuss the unique physiological barriers presented by the lung to efficient nebulised RNA delivery and approaches adopted to circumvent this problem. Additionally, the different types of nebulisers are evaluated from the perspective of their suitability for RNA delivery. Furthermore, we discuss recent preclinical studies involving nebulisation of RNA and analysis in in vitro and in vivo settings. Several studies have also demonstrated the importance of an effective delivery vector in RNA nebulisation therefore we assess the variety of lipid, polymeric and hybrid-based delivery systems utilised to date. We also consider the outlook for nebulised RNA medicinal products and the hurdles which must be overcome for successful clinical translation. In summary, nebulised RNA delivery has demonstrated promising potential for the treatment of several lung-related conditions such as asthma, COPD and cystic fibrosis, to which the mode of delivery is of crucial importance for clinical success.

Unraveling the Multifaceted Roles of Extracellular Vesicles: Insights into Biology, Pharmacology, and Pharmaceutical Applications for Drug Delivery

Extracellular vesicles (EVs) are nanoparticles released from various cell types that have emerged as powerful new therapeutic option for a variety of diseases. EVs are involved in the transmission of biological signals between cells and in the regulation of a variety of biological processes, highlighting them as potential novel targets/platforms for therapeutics intervention and/or delivery. Therefore, it is necessary to investigate new aspects of EVs' biogenesis, biodistribution, metabolism, and excretion as well as safety/compatibility of both unmodified and engineered EVs upon administration in different pharmaceutical dosage forms and delivery systems. In this review, we summarize the current knowledge of essential physiological and pathological roles of EVs in different organs and organ systems. We provide an overview regarding application of EVs as therapeutic targets, therapeutics, and drug delivery platforms. We also explore various approaches implemented over the years to improve the dosage of specific EV products for different administration routes.

Schwann cell-derived extracellular vesicles as a potential therapy for retinal ganglion cell degeneration

Optic neuropathy is the leading cause of irreversible blindness and is characterized by progressive degeneration of retinal ganglion cells (RGCs). Several studies have demonstrated that transplantation of Schwann cells (SCs) is a promising candidate therapy for optic neuropathy and that intravitreally transplanted cells exert their effect via paracrine actions. Extracellular vesicle (EV)-based therapies are increasingly recognized as a potential strategy for cell replacement therapy. In this study, we aimed to investigate the neuroprotective and regenerative effects of SC-EVs following optic nerve injury. We found that SC-EVs were internalized by RGCs in vitro and in vivo without any transfection reagents. Intriguingly, SC-EVs significantly enhanced the survival and axonal growth of primary RGCs in a coculture system. In a rat optic nerve crush model, SC-EVs mitigated RGC degeneration, prevented RGC loss, and preserved the thickness of the ganglion cell complex, as demonstrated by the statistically significant improvement in RGC counts and thickness measurements. Mechanistically, SC-EVs activated the cAMP-response element binding protein (CREB) signaling pathway and regulated reactive gliosis in ONC rats, which is crucial for RGC protection and axonal regeneration. These findings provide novel insights into the neuroprotective and regenerative properties of SC-EVs, suggesting their potential as a cell-free therapeutic strategy and natural biomaterials for neurodegenerative diseases of the central nervous system.

Accurate and Convenient Lung Cancer Diagnosis through Detection of Extracellular Vesicle Membrane Proteins via Förster Resonance Energy Transfer

Tumor-derived extracellular vesicles (EVs) are promising to monitor early stage cancer. Unfortunately, isolating and analyzing EVs from a patient's liquid biopsy are challenging. For this, we devised an EV membrane proteins detection system (EV-MPDS) based on Förster resonance energy transfer (FRET) signals between aptamer quantum dots and AIEgen dye, which eliminated the EV extraction and purification to conveniently diagnose lung cancer. In a cohort of 80 clinical samples, this system showed enhanced accuracy (100% versus 65%) and sensitivity (100% versus 55%) in cancer diagnosis as compared to the ELISA detection method. Improved accuracy of early screening (from 96.4% to 100%) was achieved by comprehensively profiling five biomarkers using a machine learning analysis system. FRET-based tumor EV-MPDS is thus an isolation-free, low-volume (1 μL), and highly accurate approach, providing the potential to aid lung cancer diagnosis and early screening.

Delivery systems of therapeutic nucleic acids for the treatment of acute lung injury/acute respiratory distress syndrome

Acute lung injury (ALI)/ acute respiratory distress syndrome (ARDS) is a devastating inflammatory lung disease with a high mortality rate. ALI/ARDS is induced by various causes, including sepsis, infections, thoracic trauma, and inhalation of toxic reagents. Corona virus infection disease-19 (COVID-19) is also a major cause of ALI/ARDS. ALI/ARDS is characterized by inflammatory injury and increased vascular permeability, resulting in lung edema and hypoxemia. Currently available treatments for ALI/ARDS are limited, but do include mechanical ventilation for gas exchange and treatments supportive of reduction of severe symptoms. Anti-inflammatory drugs such as corticosteroids have been suggested, but their clinical effects are controversial with possible side-effects. Therefore, novel treatment modalities have been developed for ALI/ARDS, including therapeutic nucleic acids. Two classes of therapeutic nucleic acids are in use. The first constitutes knock-in genes for encoding therapeutic proteins such as heme oxygenase-1 (HO-1) and adiponectin (APN) at the site of disease. The other is oligonucleotides such as small interfering RNAs and antisense oligonucleotides for knock-down expression of target genes. Carriers have been developed for efficient delivery for therapeutic nucleic acids into the lungs based on the characteristics of the nucleic acids, administration routes, and targeting cells. In this review, ALI/ARDS gene therapy is discussed mainly in terms of delivery systems. The pathophysiology of ALI/ARDS, therapeutic genes, and their delivery strategies are presented for development of ALI/ARDS gene therapy. The current progress suggests that selected and appropriate delivery systems of therapeutic nucleic acids into the lungs may be useful for the treatment of ALI/ARDS.

The potential application of encapsulated exosomes: A new approach to increase exosomes therapeutic efficacy

Cell therapy is one of the methods that have shown promising results in treating diseases in recent decades. However, the use of different types of cells comes with limitations. The application of immune cells in cell therapy can lead to cytokine storms and inappropriate responses to self-antigens. Also, the use of stem cells has the potential to create tumors. Also, cells may not migrate to the injury site after intravenous injection. Therefore, using exosomes from different cells as therapeutic candidates were proposed. Due to their small size and favorable characteristics, such as biocompatibility and immunocompatibility, the easy storage and isolation, exosomes have attracted much attention. They are used in treating many diseases, including cardiovascular diseases, orthopedic diseases, autoimmune diseases, and cancer. However, the results of various studies have shown that the therapeutic efficiency of exosomes (Exo) can be increased by loading different drugs and microRNAs inside them (encapsulated exosomes). Therefore, analyzing studies investigating encapsulated exosomes' therapeutic ability is critical. In this study, we have examined the studies related to the use of encapsulated exosomes in treating diseases such as cancer and infectious diseases and their use in regenerative medicine. Compared to intact exosomes, the results show that the application of encapsulated exosomes has a higher therapeutic ability. Therefore it is suggested to use this method depending on the treatment type to increase the treatment's efficiency.

Wnt3a-Loaded Extracellular Vesicles Promote Alveolar Epithelial Regeneration after Lung Injury

Compromised regeneration resulting from the deactivation of Wnt/β-catenin signaling contributes to the progression of chronic obstructive pulmonary disease (COPD) with limited therapeutic options. Extracellular cytokine-induced Wnt-based signaling provides an alternative option for COPD treatment. However, the hydrophobic nature of Wnt proteins limits their purification and use. This study devises a strategy to deliver the membrane-bound wingless-type MMTV integration site family, member 3A (Wnt3a) over a long distance by anchoring it to the surface of extracellular vesicles (EVs). The newly engineered Wnt3aWG EVs are generated by co-expressing Wnt3a with two genes encoding the membrane protein, WLS, and an engineered glypican, GPC6ΔGPI -C1C2. The bioactivity of Wnt3aWG EVs is validated using a TOPFlash assay and a mesoderm differentiation model of human pluripotent stem cells. Wnt3aWG EVs activate Wnt signaling and promote cell growth following human alveolar epithelial cell injury. In an elastase-induced emphysema model, impaired pulmonary function and enlarged airspace are greatly restored by the intravenous delivery of Wnt3aWG EVs. Single-cell RNA sequencing-based analyses further highlight that Wnt3aWG EV-activated regenerative programs are responsible for its beneficial effects. These findings suggest that EV-based Wnt3a delivery represents a novel therapeutic strategy for lung repair and regeneration after injury.

Carbon dots induce pathological damage to the intestine via causing intestinal flora dysbiosis and intestinal inflammation

BACKGROUND

Carbon dots (CDs), as excellent antibacterial nanomaterials, have gained great attention in treating infection-induced diseases such as periodontitis and stomatitis. Given the eventual exposure of CDs to the intestine, elucidating the effect of CDs on intestinal health is required for the safety evaluation of CDs.

RESULTS

Herein, CDs extracted from ε-poly-L-lysine (PL) were chosen to explore the modulation effect of CDs on probiotic behavior in vitro and intestinal remodeling in vivo. Results verify that PL-CDs negatively regulate Lactobacillus rhamnosus (L. rhamnosus) growth via increasing reactive oxygen species (ROS) production and reducing the antioxidant activity, which subsequently destroys membrane permeability and integrity. PL-CDs are also inclined to inhibit cell viability and accelerate cell apoptosis. In vivo, the gavage of PL-CDs is verified to induce inflammatory infiltration and barrier damage in mice. Moreover, PL-CDs are found to increase the Firmicutes to Bacteroidota (F/B) ratio and the relative abundance of Lachnospiraceae while decreasing that of Muribaculaceae.

CONCLUSION

Overall, these evidences indicate that PL-CDs may inevitably result in intestinal flora dysbiosis via inhibiting probiotic growth and simultaneously activating intestinal inflammation, thus causing pathological damage to the intestine, which provides an effective and insightful reference for the potential risk of CDs from the perspective of intestinal remodeling.

Proteomic Research of Extracellular Vesicles in Clinical Biofluid

Extracellular vesicles (EVs), the lipid bilayer membranous structures of particles, are produced and released from almost all cells, including eukaryotes and prokaryotes. The versatility of EVs has been investigated in various pathologies, including development, coagulation, inflammation, immune response modulation, and cell-cell communication. Proteomics technologies have revolutionized EV studies by enabling high-throughput analysis of their biomolecules to deliver comprehensive identification and quantification with rich structural information (PTMs, proteoforms). Extensive research has highlighted variations in EV cargo depending on vesicle size, origin, disease, and other features. This fact has sparked activities to use EVs for diagnosis and treatment to ultimately achieve clinical translation with recent endeavors summarized and critically reviewed in this publication. Notably, successful application and translation require a constant improvement of methods for sample preparation and analysis and their standardization, both of which are areas of active research. This review summarizes the characteristics, isolation, and identification approaches for EVs and the recent advances in EVs for clinical biofluid analysis to gain novel knowledge by employing proteomics. In addition, the current and predicted future challenges and technical barriers are also reviewed and discussed.

Extracellular vesicle-encapsulated CC16 as novel nanotherapeutics for treatment of acute lung injury

Acute lung injury (ALI) is still associated with high mortality. Growing evidence suggests that Club Cell Protein 16 (CC16) plays a protective role against ALI. However, the doses of recombinant CC16 (rCC16) used in preclinical studies are supraphysiological for clinical applications. Extracellular vesicles (EVs) are nanovesicles endogenously generated by mammalian cells. Our study demonstrated that CC16 is released via small EVs and EV-encapsulated CC16 (sEV-CC16) and has anti-inflammatory activities, which protect mice from lipopolysaccharide (LPS) or bacteria-induced ALI. Additionally, sEV-CC16 can activate the DNA damage repair signaling pathways. Consistent with this activity, we observed more severe DNA damage in lungs from Cc16 knockout (KO) than wild-type (WT) mice. Mechanistically, we elucidated that CC16 suppresses nuclear factor κB (NF-κB) signaling activation by binding to heat shock protein 60 (HSP60). We concluded that sEV-CC16 could be a potential therapeutic agent for ALI by inhibiting the inflammatory and DNA damage responses by reducing NF-κB signaling.

A proinflammatory long noncoding RNA Lncenc1 regulates inflammasome activation in macrophage

Mammalian genomes encode thousands of long noncoding RNAs (lncRNAs). LncRNAs are extensively expressed in various immune cells. The lncRNAs have been reported to be involved in diverse biological processes, including the regulation of gene expression, dosage compensation, and genomic imprinting. However, very little research has been conducted to explore how they alter innate immune responses during host-pathogen interactions. In this study, we found that a lncRNA, named long noncoding RNA, embryonic stem cells expressed 1 (Lncenc1), was strikingly increased in mouse lungs after gram-negative (G-) bacterial infection or exposure to lipopolysaccharides (LPS). Interestingly, our data indicated that Lncenc1 was upregulated in macrophages but not in primary epithelial cells (PECs) or polymorphonuclear leukocytes (PMN). The upregulation was also observed in human THP-1 and U937 macrophages. Besides, Lncenc1 was highly induced during ATP-induced inflammasome activation. Functionally, Lncenc1 showed proinflammatory effects in macrophages as demonstrated by increased expressions of cytokine and chemokines, as well as enhanced NF-κB promoter activity. Overexpression of Lncenc1 promoted the releases of IL-1β and IL-18, and Caspase-1 activity in macrophages, suggesting a role in inflammasome activation. Consistently, knockdown of Lncenc1 inhibited inflammasome activation in LPS-treated macrophages. Moreover, knockdown of Lncenc1 using antisense oligo (ASO)-loaded exosomes (EXO) attenuated LPS-induced lung inflammation in mice. Similarly, Lncenc1 deficiency protects mice from bacteria-induced lung injury and inflammasome activation. Taken together, our work identified Lncenc1 as a modulator of inflammasome activation in macrophages during bacterial infection. Our study suggested that Lncenc1 could serve as a therapeutic target for lung inflammation and injury.

Extracellular vesicle-loaded hydrogels for tissue repair and regeneration

Extracellular vesicles (EVs) are a collective term for nanoscale or microscale vesicles secreted by cells that play important biological roles. Mesenchymal stem cells are a class of cells with the potential for self-healing and multidirectional differentiation. In recent years, numerous studies have shown that EVs, especially those secreted by mesenchymal stem cells, can promote the repair and regeneration of various tissues and, thus, have significant potential in regenerative medicine. However, due to the rapid clearance capacity of the circulatory system, EVs are barely able to act persistently at specific sites for repair of target tissues. Hydrogels have good biocompatibility and loose and porous structural properties that allow them to serve as EV carriers, thereby prolonging the retention in certain specific areas and slowing the release of EVs. When EVs are needed to function at specific sites, the EV-loaded hydrogels can stand as an excellent approach. In this review, we first introduce the sources, roles, and extraction and characterization methods of EVs and describe their current application status. We then review the different types of hydrogels and discuss factors influencing their abilities to carry and release EVs. We summarize several strategies for loading EVs into hydrogels and characterizing EV-loaded hydrogels. Furthermore, we discuss application strategies for EV-loaded hydrogels and review their specific applications in tissue regeneration and repair. This article concludes with a summary of the current state of research on EV-loaded hydrogels and an outlook on future research directions, which we hope will provide promising ideas for researchers.

Regenerative medicine in lung diseases: A systematic review

Regenerative medicine has opened the door to the exploration of new therapeutic methods for the treatment of various diseases, especially those associated with local or general disregulation of the immune system. In pulmonary diseases, new therapeutic strategies have emerged that are aimed at restoring functional lung tissue rather than alleviating symptoms. These strategies focus on tissue regeneration using stem cells and/or their derivatives or replacement of dysfunctional tissue using biomedical engineering. Animal health can directly benefit from regenerative therapy strategies and also serve as a translational experimental model for human disease. Several clinical trials have been conducted to evaluate the effects of cellular treatment on inflammatory lung disease in animals. Data reported to date show several beneficial effects in ex vivo and in vivo models; however, our understanding of the mechanisms that regenerative therapies exert on diseased tissues remains incomplete.