Airway epithelial-targeted nanoparticles for asthma therapy

Bottlebrush Polyethylene Glycol Nanocarriers Translocate across Human Airway Epithelium via Molecular Architecture-Enhanced Endocytosis

Pulmonary drug delivery is critical for the treatment of respiratory diseases. However, the human airway surface presents multiple barriers to efficient drug delivery. Here, we report a bottlebrush poly(ethylene glycol) (PEG-BB) nanocarrier that can translocate across all barriers within the human airway surface. Guided by a molecular theory, we design a PEG-BB molecule consisting of a linear backbone densely grafted by many (∼1000) low molecular weight (∼1000 g/mol) polyethylene glycol (PEG) chains; this results in a highly anisotropic, wormlike nanocarrier featuring a contour length of ∼250 nm, a cross-section of ∼20 nm, and a hydrodynamic diameter of ∼40 nm. Using the classic air-liquid-interface culture system to recapitulate essential biological features of the human airway surface, we show that PEG-BB rapidly penetrates through endogenous airway mucus and periciliary brush layer (mesh size of 20-40 nm) to be internalized by cells across the whole epithelium. By quantifying the cellular uptake of polymeric carriers of various molecular architectures and manipulating cell proliferation and endocytosis pathways, we show that the translocation of PEG-BB across the epithelium is driven by bottlebrush architecture-enhanced endocytosis. Our results demonstrate that large, wormlike bottlebrush PEG polymers, if properly designed, can be used as a carrier for pulmonary and mucosal drug delivery.

Construction of a three-dimensional inflammation model of human bronchial epithelial cells BEAS-2B by using the self-assembling D-form peptide Sciobio-Ⅲ

Human bronchial epithelial cells in the airway system, as the primary barrier between humans and the surrounding environment, assume a crucial function in orchestrating the processes of airway inflammation. Target to develop a new three-dimensional (3D) inflammatory model to airway system, and here we report a strategy by using self-assembling D-form peptide to cover the process. By testing physicochemical properties and biocompatibility of Sciobio-Ⅲ, we confirmed that it can rapidly self-assembles under the trigger of ions to form a 3D nanonetwork-like scaffold, which supports 3D cell culture including the cell strains like BEAS-2B cells. Subsequently, inflammation model was established by lipopolysaccharide (LPS), the expression of some markers of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), interleukin-6 (IL-6), and interleukin-8 (IL-8), the levels of relevant inflammatory factors were measured by RT-qPCR and the secretion profile of inflammatory cytokines by ELISA, are obtained the quite difference effects in 2D and 3D microenvironment, which suggested Sciobio-Ⅲ hydrogel is an ideal scaffold that create the microenvironment for 3D cell culture. Here we are success to establish a 3D inflammation model for airway system. This innovative model allows for rapid and accurate evaluation of drug metabolism and toxicological side effects, hope to use in drug screening for airway inflammatory diseases and beyond.

Bottlebrush polyethylene glycol nanocarriers translocate across human airway epithelium via molecular architecture enhanced endocytosis

Pulmonary drug delivery is critical to the treatment of respiratory diseases. However, the human airway surface presents multiscale barriers to efficient drug delivery. Here we report a bottlebrush polyethylene glycol (PEG-BB) nanocarrier that can translocate across all barriers within the human airway surface. Guided by the molecular theory, we design a PEG-BB molecule consisting of a linear backbone densely grafted by many (∼1,000) low molecular weight (∼1000 g/mol) PEG chains; this results in a highly anisotropic, wormlike nanocarrier featuring a contour length of ∼250 nm, a cross-section of ∼20 nm, and a hydrodynamic diameter of ∼40 nm. Using the classic air-liquid-interface culture system to recapitulate essential biological features of the human airway surface, we show that PEG-BB rapidly penetrates through endogenous airway mucus and periciliary brush layer (mesh size of 20-40 nm) to be internalized by cells across the whole epithelium. By quantifying the cellular uptake of polymeric carriers of various molecular architectures and manipulating cell proliferation and endocytosis pathways, we show that the translocation of PEG-BB across the epithelium is driven by bottlebrush architecture enhanced endocytosis. Our results demonstrate that large, wormlike bottlebrush PEG polymers, if properly designed, can be used as a novel carrier for pulmonary and mucosal drug delivery.

Table of Contents

Inhaled RNA drugs to treat lung diseases: Disease-related cells and nano-bio interactions

In recent years, RNA-based therapies have gained much attention as biomedicines due to their remarkable therapeutic effects with high specificity and potency. Lung diseases offer a variety of currently undruggable but attractive targets that could potentially be treated with RNA drugs. Inhaled RNA drugs for the treatment of lung diseases, including asthma, chronic obstructive pulmonary disease, cystic fibrosis, and acute respiratory distress syndrome, have attracted more and more attention. A variety of novel nanoformulations have been designed and attempted for the delivery of RNA drugs to the lung via inhalation. However, the delivery of RNA drugs via inhalation poses several challenges. It includes protection of the stability of RNA molecules, overcoming biological barriers such as mucus and cell membrane to the delivery of RNA molecules to the targeted cytoplasm, escaping endosomal entrapment, and circumventing unwanted immune response etc. To address these challenges, ongoing researches focus on developing innovative nanoparticles to enhance the stability of RNA molecules, improve cellular targeting, enhance cellular uptake and endosomal escape to achieve precise delivery of RNA drugs to the intended lung cells while avoiding unwanted nano-bio interactions and off-target effects. The present review first addresses the pathologic hallmarks of different lung diseases, disease-related cell types in the lung, and promising therapeutic targets in these lung cells. Subsequently we highlight the importance of the nano-bio interactions in the lung that need to be addressed to realize disease-related cell-specific delivery of inhaled RNA drugs. This is followed by a review on the physical and chemical characteristics of inhaled nanoformulations that influence the nano-bio interactions with a focus on surface functionalization. Finally, the challenges in the development of inhaled nanomedicines and some key aspects that need to be considered in the development of future inhaled RNA drugs are discussed.

Impact of a Polymer-Based Nanoparticle with Formoterol Drug as Nanocarrier System In Vitro and in an Experimental Asthmatic Model

The implementation of nanotechnology in pulmonary delivery systems might result in better and more specific therapy. Therefore, a nano-sized drug carrier should be toxicologically inert and not induce adverse effects. We aimed to investigate the responses of a polymer nano drug carrier, a lysine poly-hydroxyethyl methacrylate nanoparticle (NP) [Lys-p(HEMA)], loaded with formoterol, both in vitro and in vivo in an ovalbumin (OVA) asthma model. The successfully synthesized nanodrug formulation showed an expectedly steady in vitro release profile. There was no sign of in vitro toxicity, and the 16HBE and THP-1 cell lines remained vital after exposure to the nanocarrier, both loaded and unloaded. In an experimental asthma model (Balb/c mice) of ovalbumin sensitization and challenge, the nanocarrier loaded and unloaded with formoterol was tested in a preventive strategy and compared to treatment with the drug in a normal formulation. The airway hyperresponsiveness (AHR) and pulmonary inflammation in the bronchoalveolar lavage (BAL), both cellular and biochemical, were assessed. The application of formoterol as a regular drug and the unloaded and formoterol-loaded NP in OVA-sensitized mice followed by a saline challenge was not different from the control group. Yet, both the NP formulation and the normal drug application led to a more deteriorated lung function and increased lung inflammation in the OVA-sensitized and -challenged mice, showing that the use of the p(HEMA) nanocarrier loaded with formoterol needs more extensive testing before it can be applied in clinical settings.

Airway mucus in pulmonary diseases: Muco-adhesive and muco-penetrating particles to overcome the airway mucus barriers

Airway mucus is a complex viscoelastic gel that provides a defensive physical barrier and shields the airway epithelium by trapping inhaled foreign pathogens and facilitating their removal via mucociliary clearance (MCC). In patients with respiratory diseases, such as chronic obstructive pulmonary disease (COPD), cystic fibrosis (CF), non-CF bronchiectasis, and asthma, an increase in crosslinking and physical entanglement of mucin polymers as well as mucus dehydration often alters and typically reduces mucus mesh network pore size, which reduces neutrophil migration, decreases pathogen capture, sustains bacterial infection, and accelerates lung function decline. Conventional aerosol particles containing hydrophobic drugs are rapidly captured and removed by MCC. Therefore, it is critical to design aerosol delivery systems with the appropriate size and surface chemistry that can improve drug retention and absorption with the goal of increased efficacy. Biodegradable muco-adhesive particles (MAPs) and muco-penetrating particles (MPPs) have been engineered to achieve effective pulmonary delivery and extend drug residence time in the lungs. MAPs can be used to target mucus as they get trapped in airway mucus by steric obstruction and/or adhesion. MPPs avoid muco-adhesion and are designed to have a particle size smaller than the mucus network, enhancing lung retention of particles as well as transport to the respiratory epithelial layer and drug absorption. In this review, we aim to provide insight into the composition of airway mucus, rheological characteristics of airway mucus in healthy and diseased subjects, the most recent techniques to study the flow dynamics and particle diffusion in airway mucus (in particular, multiple particle tracking, MPT), and the advancements in engineering MPPs that have contributed to improved airway mucus penetration, lung distribution, and retention.

Ligustilide attenuates airway remodeling in COPD mice by covalently binding to MH2 domain of Smad3 in pulmonary epithelium, disrupting the Smad3-SARA interaction

Airway remodeling is one of the hallmarks of chronic obstructive pulmonary disease (COPD) and is closely related to the dysregulation of epithelial-mesenchymal transition (EMT). Smad3, an important transcriptional regulator responsible for transducing TGF-β1 signals, is a promising target for EMT modulation. We found that ligustilide (Lig), a novel Smad3 covalent inhibitor, effectively inhibited airway remodeling in cigarette smoke (CS) combined with lipopolysaccharide (LPS)-induced COPD mice. Oral administration of an alkynyl-modified Lig probe was used to capture and trace target proteins in mouse lung tissue, revealing Smad3 in airway epithelium as a key target of Lig. Protein mass spectrometry and Smad3 mutation analysis via in-gel imaging indicated that the epoxidized metabolite of Lig covalently binds to the MH2 domain of Smad3 at Cys331/337. This irreversible bonding destroys the interaction of Smad3-SARA, prevents Smad3 phosphorylation activation, and subsequently suppresses the nuclear transfer of p-Smad3, the EMT process, and collagen deposition in TGF-β1-stimulated BEAS-2B cells and COPD mice. These findings provide experimental support that Lig attenuates COPD by repressing airway remodeling which is attributed to its suppression on the activation of EMT process in the airway epithelium via targeting Smad3 and inhibiting the recruitment of the Smad3-SARA heterodimer in the TGF-β1/Smad3 pathway.

Chlorotoxin and Lung Cancer: A Targeting Perspective for Drug Delivery

In the generational evolution of nano-based drug delivery carriers, active targeting has been a major milestone for improved and selective drug accumulation in tissues and cell types beyond the existing passive targeting capabilities. Among the various active targeting moieties, chlorotoxin, a peptide extracted from scorpions, demonstrated promising tumor cell accumulation and selection. With lung cancer being among the leading diagnoses of cancer-related deaths in both men and women, novel therapeutic methodologies utilizing nanotechnology for drug delivery emerged. Given chlorotoxin's promising biological activity, we explore its potential against lung cancer and its utilization for active targeting against this cancer's tumor cells. Our analysis indicates that despite the extensive chlorotoxin's research against glioblastoma, lung cancer research with the molecule has been limited, despite some promising early results.

Toll-like receptor-agonist-based therapies for respiratory viral diseases: thinking outside the cell

Respiratory virus infections initiate in the upper respiratory tract (URT). Innate immunity is critical for initial control of infection at this site, particularly in the absence of mucosal virus-neutralising antibodies. If the innate immune response is inadequate, infection can spread to the lower respiratory tract (LRT) causing community-acquired pneumonia (as exemplified by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)/coronavirus disease 2019). Vaccines for respiratory viruses (influenza and SARS-CoV-2) leverage systemic adaptive immunity to protect from severe lung disease. However, the URT remains vulnerable to infection, enabling viral transmission and posing an ongoing risk of severe disease in populations that lack effective adaptive immunity.

Innate immunity is triggered by host cell recognition of viral pathogen-associated molecular patterns via molecular sensors such as Toll-like receptors (TLRs). Here we review the role of TLRs in respiratory viral infections and the potential of TLR-targeted treatments to enhance airway antiviral immunity to limit progression to severe LRT disease and reduce person-to-person viral transmission. By considering cellular localisation and antiviral mechanisms of action and treatment route/timing, we propose that cell surface TLR agonist therapies are a viable strategy for preventing respiratory viral diseases by providing immediate, durable pan-viral protection within the URT.

Respiratory virus infections are a significant disease burden and new treatment options are required. Treatments that stimulate innate immunity in the upper respiratory tract by targeting Toll-like receptors may provide rapid, pan-viral protection.https://bit.ly/3BNH2Em

Packaging and Delivery of Asthma Therapeutics

Asthma is a life-altering, chronic disease of heterogenous origin that features a complex interplay of immune and environmental signaling. Although very little progress has been made in prevention, diverse types of medications and delivery systems, including nanoscale systems, have been or are currently being developed to control airway inflammation and prevent exacerbations and fibrosis. These medications are delivered through mechanical methods, with various inhalers (with benefits and drawbacks) existing, and new types offering some variety in delivery. Of particular interest is the progress being made in nanosized materials for efficient penetration into the epithelial mucus layer and delivery into the deepest parts of the lungs. Liposomes, nanoparticles, and extracellular vesicles, both natural and synthetic, have been explored in animal models of asthma and have produced promising results. This review will summarize and synthesize the latest developments in both macro-(inhaler) and micro-sized delivery systems for the purpose of treating asthma patients.

Nanoparticle-Based Drug Delivery System: The Magic Bullet for the Treatment of Chronic Pulmonary Diseases

Chronic pulmonary diseases encompass different persistent and lethal diseases, including chronic obstructive pulmonary disease (COPD), idiopathic pulmonary fibrosis (IPF), cystic fibrosis (CF), asthma, and lung cancers that affect millions of people globally. Traditional pharmacotherapeutic treatment approaches (i.e., bronchodilators, corticosteroids, chemotherapeutics, peptide-based agents, etc.) are not satisfactory to cure or impede diseases. With the advent of nanotechnology, drug delivery to an intended site is still difficult, but the nanoparticle's physicochemical properties can accomplish targeted therapeutic delivery. Based on their surface, size, density, and physical-chemical properties, nanoparticles have demonstrated enhanced pharmacokinetics of actives, achieving the spotlight in the drug delivery research field. In this review, the authors have highlighted different nanoparticle-based therapeutic delivery approaches to treat chronic pulmonary diseases along with the preparation techniques. The authors have remarked the nanosuspension delivery via nebulization and dry powder carrier is further effective in the lung delivery system since the particles released from these systems are innumerable to composite nanoparticles. The authors have also outlined the inhaled particle's toxicity, patented nanoparticle-based pulmonary formulations, and commercial pulmonary drug delivery devices (PDD) in other sections. Recently advanced formulations employing nanoparticles as therapeutic carriers for the efficient treatment of chronic pulmonary diseases are also canvassed.

Lung Inflammatory Response to Environmental Dust Exposure in Mice Suggests a Link to Regional Respiratory Disease Risk

PURPOSE

The Salton Sea, California's largest lake, is designated as an agricultural drainage reservoir. In recent years, the lake has experienced shrinkage due to reduced water sources, increasing levels of aerosolized dusts in surrounding regions. Communities surrounding the Salton Sea have increased asthma prevalence versus the rest of California; however, a connection between dust inhalation and lung health impacts has not been defined.

METHODS

We used an established intranasal dust exposure murine model to study the lung inflammatory response following single or repetitive (7-day) exposure to extracts of dusts collected in regions surrounding the Salton Sea (SSDE), complemented with in vitro investigations assessing SSDE impacts on the airway epithelium.

RESULTS

In these investigations, single or repetitive SSDE exposure induced significant lung inflammatory cytokine release concomitant with neutrophil influx. Repetitive SSDE exposure led to significant lung eosinophil recruitment and altered expression of genes associated with allergen-mediated immune response, including Clec4e. SSDE treatment of human bronchial epithelial cells (BEAS-2B) induced inflammatory cytokine production at 5- and 24-hours post-treatment. When BEAS-2B were exposed to protease activity-depleted SSDE (PDSSDE) or treated with SSDE in the context of protease-activated receptor-1 and -2 antagonism, inflammatory cytokine release was decreased. Furthermore, repetitive exposure to PDSSDE led to decreased neutrophil and eosinophilic influx and IL-6 release in mice compared to SSDE-challenged mice.

CONCLUSION

These investigations demonstrate potent lung inflammatory responses and tissue remodeling in response to SSDE, in part due to environmental proteases found within the dusts. These studies provide the first evidence supporting a link between environmental dust exposure, protease-mediated immune activation, and respiratory disease in the Salton Sea region.

Nanoparticle Delivery Systems with Cell-Specific Targeting for Pulmonary Diseases

Respiratory disorders are among the most important medical problems threatening human life. The conventional therapeutics for respiratory disorders are hindered by insufficient drug concentrations at pathological lesions, lack of cell-specific targeting, and various biobarriers in the conducting airways and alveoli. To address these critical issues, various nanoparticle delivery systems have been developed to serve as carriers of specific drugs, DNA expression vectors, and RNAs. The unique properties of nanoparticles, including controlled size and distribution, surface functional groups, high payload capacity, and drug release triggering capabilities, are tailored to specific requirements in drug/gene delivery to overcome major delivery barriers in pulmonary diseases. To avoid off-target effects and improve therapeutic efficacy, nanoparticles with high cell-targeting specificity are essential for successful nanoparticle therapies. Furthermore, low toxicity and high degradability of the nanoparticles are among the most important requirements in the nanoparticle designs. In this review, we provide the most up-to-date research and clinical outcomes in nanoparticle therapies for pulmonary diseases. We also address the current critical issues in key areas of pulmonary cell targeting, biosafety and compatibility, and molecular mechanisms for selective cellular uptake.

Extracellular Vesicles from Airway Secretions: New Insights in Lung Diseases

Lung diseases (LD) are one of the most common causes of death worldwide. Although it is known that chronic airway inflammation and excessive tissue repair are processes associated with LD such as asthma, chronic obstructive pulmonary disease (COPD) or idiopathic pulmonary fibrosis (IPF), their specific pathways remain unclear. Extracellular vesicles (EVs) are heterogeneous nanoscale membrane vesicles with an important role in cell-to-cell communication. EVs are present in general biofluids as plasma or urine but also in secretions of the airway as bronchoalveolar lavage fluid (BALF), induced sputum (IS), nasal lavage (NL) or pharyngeal lavage. Alterations of airway EV cargo could be crucial for understanding LD. Airway EVs have shown a role in the pathogenesis of some LD such as eosinophil increase in asthma, the promotion of lung cancer in vitro models in COPD and as biomarkers to distinguishing IPF in patients with diffuse lung diseases. In addition, they also have a promising future as therapeutics for LD. In this review, we focus on the importance of airway secretions in LD, the pivotal role of EVs from those secretions on their pathophysiology and their potential for biomarker discovery.

Nanomedicine strategies to target coronavirus

With the severe acute respiratory syndrome coronavirus (SARS-CoV) in 2002, the middle east respiratory syndrome CoV (MERS-CoV) in 2012 and the recently discovered SARS-CoV-2 in December 2019, the 21st first century has so far faced the outbreak of three major coronaviruses (CoVs). In particular, SARS-CoV-2 spread rapidly over the globe affecting nearly 25.000.000 people up to date. Recent evidences pointing towards mutations within the viral spike proteins of SARS-CoV-2 that are considered the cause for this rapid spread and currently around 300 clinical trials are running to find a treatment for SARS-CoV-2 infections. Nanomedicine, the application of nanocarriers to deliver drugs specifically to a target sites, has been applied for different diseases, such as cancer but also in viral infections. Nanocarriers can be designed to encapsulate vaccines and deliver them towards antigen presenting cells or function as antigen-presenting carriers themselves. Furthermore, drugs can be encapsulated into such carriers to directly target them to infected cells. In particular, virus-mimicking nanoparticles (NPs) such as self-assembled viral proteins, virus-like particles or liposomes, are able to replicate the infection mechanism and can not only be used as delivery system but also to study viral infections and related mechanisms. This review will provide a detailed description of the composition and replication strategy of CoVs, an overview of the therapeutics currently evaluated in clinical trials against SARS-CoV-2 and will discuss the potential of NP-based vaccines, targeted delivery of therapeutics using nanocarriers as well as using NPs to further investigate underlying biological processes in greater detail.

Noncanonical role for Ku70/80 in the prevention of allergic airway inflammation via maintenance of airway epithelial cell organelle homeostasis

Airway epithelial homeostasis is under constant threat due to continuous exposure to the external environment, and abnormally robust sensitivity to external stimuli is critical to the development of airway diseases, including asthma. Ku is a key nonhomologous end-joining DNA repair protein with diverse cellular functions such as VDJ recombination and telomere length maintenance. Here, we show a novel function of Ku in alleviating features of allergic airway inflammation via the regulation of mitochondrial and endoplasmic reticulum (ER) stress. We first determined that airway epithelial cells derived from both asthmatic lungs and murine asthma models demonstrate increased expression of 8-hydroxy-deoxyguanosine (8-OHdG), a marker of oxidative DNA damage. Ku protein expression was dramatically reduced in the bronchial epithelium of patients with asthma as well as in human bronchial epithelial cells exposed to oxidative stress. Knockdown of Ku70 or Ku80 in naïve mice elicited mitochondrial collapse or ER stress, leading to bronchial epithelial cell apoptosis and spontaneous development of asthma-like features, including airway hyperresponsiveness, airway inflammation, and subepithelial fibrosis. These findings demonstrate an essential noncanonical role for Ku proteins in asthma pathogenesis, likely via maintenance of organelle homeostasis. This novel function of Ku proteins may also be important in other disease processes associated with organelle stress.