DNA nanoparticle-mediated thymulin gene therapy prevents airway remodeling in experimental allergic asthma

Therapeutic Supramolecular Polymers: Designs and Applications

The self-assembly of low-molecular-weight building motifs into supramolecular polymers has unlocked a new realm of materials with distinct properties and tremendous potential for advancing medical practices. Leveraging the reversible and dynamic nature of non-covalent interactions, these supramolecular polymers exhibit inherent responsiveness to their microenvironment, physiological cues, and biomolecular signals, making them uniquely suited for diverse biomedical applications. In this review, we intend to explore the principles of design, synthesis methodologies, and strategic developments that underlie the creation of supramolecular polymers as carriers for therapeutics, contributing to the treatment and prevention of a spectrum of human diseases. We delve into the principles underlying monomer design, emphasizing the pivotal role of non-covalent interactions, directionality, and reversibility. Moreover, we explore the intricate balance between thermodynamics and kinetics in supramolecular polymerization, illuminating strategies for achieving controlled sizes and distributions. Categorically, we examine their exciting biomedical applications: individual polymers as discrete carriers for therapeutics, delving into their interactions with cells, and in vivo dynamics; and supramolecular polymeric hydrogels as injectable depots, with a focus on their roles in cancer immunotherapy, sustained drug release, and regenerative medicine. As the field continues to burgeon, harnessing the unique attributes of therapeutic supramolecular polymers holds the promise of transformative impacts across the biomedical landscape.

Extracellular vesicles from adipose stem cells ameliorate allergic rhinitis in mice by immunomodulatory

Background

Human adipose tissue-derived stem cells (hADSCs) exert potent immunosuppressive effects in the allogeneic transplantation treatment. In mouse model of allergic rhinitis (AR), ADSCs partially ameliorated AR. However, no study has evaluated the potential therapeutic effects of hADSC-derived extracellular vesicles (hADSC-EVs) on AR.

Methods

Female BALB/c mice were sensitized and challenged with ovalbumin (OVA) to induce AR. One day after the last nasal drop, each group received phosphate buffered saline (PBS) or hADSC-EVs treatment. Associated symptoms and biological changes were then assessed.

Results

hADSC-EV treatment significantly alleviated nasal symptoms, and reduced inflammatory infiltration. Serum levels of OVA-specific IgE, interleukin (IL)-4 and interferon (IFN)-γ were all significantly reduced. The mRNA levels of IL-4 and IFN-γ in the spleen also changed accordingly. The T helper (Th)1/Th2 cell ratio increased. The treatment efficacy index of hADSC-EV was higher than that of all human-derived MSCs in published reports on MSC treatment of AR. ADSC-EVs exhibited a greater therapeutic index in most measures when compared to our previous treatment involving ADSCs.

Conclusion

These results demonstrated that hADSC-EVs could ameliorate the symptoms of AR by modulating cytokine secretion and Th1/Th2 cell balance. hADSC-EVs could potentially be a viable therapeutic strategy for AR. Further animal studies are needed to elucidate the underlying mechanisms and to optimize potential clinical protocols.

Gene Therapy for Immunoglobulin E, Complement-Mediated, and Eosinophilic Disorders

Immunoglobulin E, complement, and eosinophils play an important role in host defense, but dysfunction of each of these components can lead to a variety of human disorders. In this review, we summarize how investigators have adapted gene therapy and antisense technology to modulate immunoglobulin E, complement, and/or eosinophil levels to treat these disorders.

Thymus-derived hormonal and cellular control of cancer

The thymus gland is a central lymphoid organ in which developing T cell precursors, known as thymocytes, undergo differentiation into distinct type of mature T cells, ultimately migrating to the periphery where they exert specialized effector functions and orchestrate the immune responses against tumor cells, pathogens and self-antigens. The mechanisms supporting intrathymic T cell differentiation are pleiotropically regulated by thymic peptide hormones and cytokines produced by stromal cells in the thymic microenvironment and developing thymocytes. Interestingly, in the same way as T cells, thymic hormones (herein exemplified by thymosin, thymulin and thymopoietin), can circulate to impact immune cells and other cellular components in the periphery. Evidence on how thymic function influences tumor cell biology and response of patients with cancer to therapies remains unsatisfactory, although there has been some improvement in the knowledge provided by recent studies. Herein, we summarize research progression in the field of thymus-mediated immunoendocrine control of cancer, providing insights into how manipulation of the thymic microenvironment can influence treatment outcomes, including clinical responses and adverse effects of therapies. We review data obtained from clinical and preclinical cancer research to evidence the complexity of immunoendocrine interactions underpinning anti-tumor immunity.

Inhaled drug delivery for the targeted treatment of asthma

Asthma is a chronic lung disease affecting millions worldwide. While classically acknowledged to result from allergen-driven type 2 inflammatory responses leading to IgE and cytokine production and the influx of immune cells such as mast cells and eosinophils, the wide range in asthmatic pathobiological subtypes lead to highly variable responses to anti-inflammatory therapies. Thus, there is a need to develop patient-specific therapies capable of addressing the full spectrum of asthmatic lung disease. Moreover, delivery of targeted treatments for asthma directly to the lung may help to maximize therapeutic benefit, but challenges remain in design of effective formulations for the inhaled route. In this review, we discuss the current understanding of asthmatic disease progression as well as genetic and epigenetic disease modifiers associated with asthma severity and exacerbation of disease. We also overview the limitations of clinically available treatments for asthma and discuss pre-clinical models of asthma used to evaluate new therapies. Based on the shortcomings of existing treatments, we highlight recent advances and new approaches to treat asthma via inhalation for monoclonal antibody delivery, mucolytic therapy to target airway mucus hypersecretion and gene therapies to address underlying drivers of disease. Finally, we conclude with discussion on the prospects for an inhaled vaccine to prevent asthma.

Gene therapy for alpha-1 antitrypsin deficiency: an update

INTRODUCTION

Altering the human genetic code has been explored since the early 1990s as a definitive answer for the treatment of monogenic and acquired diseases which do not respond to conventional therapies. In Alpha-1 antitrypsin deficiency (AATD) the proper synthesis and secretion of alpha-1 antitrypsin (AAT) protein is impaired, leading to its toxic hepatic accumulation along with its pulmonary insufficiency, which is associated with parenchymal proteolytic destruction. Because AATD is caused by mutations in a single gene whose correction alone would normalize the mutant phenotype, it has become a popular target for both augmentation gene therapy and gene editing. Although gene therapy products are already a reality for the treatment of some pathologies, such as inherited retinal dystrophy and spinal muscular atrophy, AATD-related pulmonary and, especially, liver diseases still lack effective therapeutic options.

AREAS COVERED

Here, we review the course, challenges, and achievements of AATD gene therapy as well as update on new strategies being developed.

EXPERT OPINION

Reaching safe and clinically effective expression of the AAT is currently the greatest challenge for AATD gene therapy. The improvement and emergence of technologies that use gene introduction, silencing and correction hold promise for the treatment of AATD.

Pharmacological Strategies and Recent Advancement in Nano-Drug Delivery for Targeting Asthma

With a high prevalence globally, asthma is a severe hazard to human health, as well as an economic and social burden. There are now novel therapies available for asthma with the use of nanotechnology. Recent developments in nanoscience and medicine have encouraged the creation of inhalable nanomedicines that can enhance the efficacy, patient compliance, and life quality for sufferers of asthma. Nanocarriers for asthma therapy, including liposomes, micelles, polymers, dendrimers, and inorganics, are presented in depth in this study as well as the current research status of these nanocarriers. Aerosolized nanomaterial-based drug transport systems are currently being developed, and some examples of these systems, as well as prospective future paths, are discussed. New research subjects include nano-modification of medicines and the development of innovative nano-drugs. Clinical experiments have proven that nanocarriers are both safe and effective. Before nanotherapy can be applied in clinical practice, several obstacles must be addressed. We look at some of the most recent research discoveries in the subject of nanotechnology and asthma therapy in this article.

Novel Insights into the Therapeutic Potential of Lung-Targeted Gene Transfer in the Most Common Respiratory Diseases

Over the past decades, a better understanding of the genetic and molecular alterations underlying several respiratory diseases has encouraged the development of new therapeutic strategies. Gene therapy offers new therapeutic alternatives for inherited and acquired diseases by delivering exogenous genetic materials into cells or tissues to restore physiological protein expression and/or activity. In this review, we review (1) different types of viral and non-viral vectors as well as gene-editing techniques; and (2) the application of gene therapy for the treatment of respiratory diseases and disorders, including pulmonary arterial hypertension, idiopathic pulmonary fibrosis, cystic fibrosis, asthma, alpha-1 antitrypsin deficiency, chronic obstructive pulmonary disease, non-small-cell lung cancer, and COVID-19. Further, we also provide specific examples of lung-targeted therapies and discuss the major limitations of gene therapy.

Recent advances in development of nano-carriers for immunogene therapy in various complex disorders

Immunotherapy is a novel preference for the treatment of various complex diseases. Considering the application of varying agents for suppression or activation of the immune system, immunogene therapy was confirmed to stand as a proper alternative for other immunotherapeutic strategies due to its capability in targeting cells with more specificity that leads to controlling the expression of therapeutic genes. This method facilitates the local and single-dose application of most gene therapies that result in the usage of high therapeutic doses with a low risk of systemic side effects while being cost-efficient in long-term administrations. However, the existing barriers between the administration site and cell nucleus limited the clinical uses of genetic materials. These challenges can be overcome through the promising method of exerting non-carriers with high stability, low toxicity/immunogenicity, and simple modifications. In this study, we attempted to review the potential of nanoparticle application throughout the immunogene therapy of different diseases including cancer, microbial diseases, allergies, inflammatory bowel disease, rheumatoid arthritis, and respiratory infections. We included the outline of some challenges and opportunities in regards to the delivery of genetic materials that are based on nano-systems through immunotherapy of these disorders. Next to the promising future of these vectors, more detailed analyses are required to overcome the current limitations in clinical approaches.

Concepts of advanced therapeutic delivery systems for the management of remodeling and inflammation in airway diseases

Chronic respiratory disorders affect millions of people worldwide. Pathophysiological changes to the normal airway wall structure, including changes in the composition and organization of its cellular and molecular constituents, are referred to as airway remodeling. The inadequacy of effective treatment strategies and scarcity of novel therapies available for the treatment and management of chronic respiratory diseases have given rise to a serious impediment in the clinical management of such diseases. The progress made in advanced drug delivery, has offered additional advantages to fight against the emerging complications of airway remodeling. This review aims to address the gaps in current knowledge about airway remodeling, the relationships between remodeling, inflammation, clinical phenotypes and the significance of using novel drug delivery methods.

Bridging micro/nano-platform and airway allergy intervention

Allergic airway diseases, with incidence augmenting visibly as industrial development and environmental degradation, are characterized by sneezing, itching, wheezing, chest tightness, airway obstruction, and hyperresponsiveness. Current medical modalities attempt to combat these symptoms mostly by small molecule chemotherapeutants, such as corticosteroids, antihistamines, etc., via intranasal approach which is one of the most noninvasive, rapid-absorbed, and patient-friendly routes. Nevertheless, inherent defects for irritation to respiratory mucosa, drug inactivation and degradation, and rapid drug dispersal to off-target sites are inevitable. Lately, intratracheal micro/nano therapeutic systems are emerging as innovative alternatives for airway allergy interventions. This overview introduces several potential application directions of mic/nano-platform in the treatment of airway allergic diseases, including carriers, therapeutic agents, and immunomodulators. The improvement of the existing drug therapy of respiratory allergy management by micro/nano-platform is described in detail. The challenges of the micro/nano-platform nasal approach in the treatment of airway allergy are summarized and the development of micro/nano-platform is also prospected. Although still a burgeoning area, micro/nano therapeutic systems are gradually turning to be realistic orientations as crucial future alternative therapeutic options in allergic airway inflammation interventions.

Thymus Gland: A Double Edge Sword for Coronaviruses

The thymus is the main lymphoid organ that regulates the immune and endocrine systems by controlling thymic cell proliferation and differentiation. The gland is a primary lymphoid organ responsible for generating mature T cells into CD4+ or CD8+ single-positive (SP) T cells, contributing to cellular immunity. Regarding humoral immunity, the thymic plasma cells almost exclusively secrete IgG1 and IgG3, the two main complement-fixing effector IgG subclasses. Deformity in the thymus can lead to inflammatory diseases. Hassall’s corpuscles’ epithelial lining produces thymic stromal lymphopoietin, which induces differentiation of CDs thymocytes into regulatory T cells within the thymus medulla. Thymic B lymphocytes produce immunoglobulins and immunoregulating hormones, including thymosin. Modulation in T cell and naive T cells decrement due to thymus deformity induce alteration in the secretion of various inflammatory factors, resulting in multiple diseases. Influenza virus activates thymic CD4+ CD8+ thymocytes and a large amount of IFNγ. IFNs limit virus spread, enhance macrophages’ phagocytosis, and promote the natural killer cell restriction activity against infected cells. Th2 lymphocytes-produced cytokine IL-4 can bind to antiviral INFγ, decreasing the cell susceptibility and downregulating viral receptors. COVID-19 epitopes (S, M, and N proteins) with ≥90% identity to the SARS-CoV sequence have been predicted. These epitopes trigger immunity for antibodies production. Boosting the immune system by improving thymus function can be a therapeutic strategy for preventing virus-related diseases. This review aims to summarize the endocrine-immunoregulatory functions of the thymus and the underlying mechanisms in the prevention of COVID-19.

Nanotechnology based advanced therapeutic strategies for targeting interleukins in chronic respiratory diseases

Both communicable and non-communicable chronic respiratory conditions have accorded for suffering of millions of people of all ages and stated to be leading cause of death, morbidity, economic and social pressures, and disability-adjusted life-years (DALYs) worldwide. These illnesses impair patient's health and negatively impacts families and society, particularly in low and middle-income countries. Chronic respiratory diseases (CRDs) affect different organs of respiratory system, involving airways, parenchyma, and pulmonary vasculature. As the number of respiratory diseases are exponentially escalating but still the stakeholders are not paying attention towards its serious complications. Currently, the treatment being used primarily focusses only on alleviating symptoms of these illness rather delivering the therapeutic agent at target site for optimal care and/or prevention. Lately, extensive research is being conducted on airways and systemic inflammation, oxidative stress, airway, or parenchymal rehabilitation. From which macrophages, neutrophils, and T cells, as well as structural cells as fibroblasts, epithelial, endothelial, and smooth muscle cells have been found to be active participants that are involved in these chronic respiratory diseases. The pathogenesis of all these chronic respiratory diseases gets caused differently via mediators and proteins, including cytokines, chemokines, growth factors and oxidants. Presently, the target of prescription therapies is to reduce the inflammation of airways and relieve the airway contraction. In all studies, cytokines have been found to play an imperative role in fostering chronic airway inflammation and remodelling. Owing to the limitations of conventional treatments, the current review aims to summarize the current knowledge about the chronic respiratory disease and discuss further about the various conventional methods that can be used for treating this ailment. Additionally, it also highlights and discusses about the advanced drug delivery system that are being used for targeting the interleukins for the treatment of CRDs.

Co-Injection of Sulfotyrosine Facilitates Retinal Uptake of Hyaluronic Acid Nanospheres Following Intravitreal Injection

Gene and drug delivery to the retina is a critical therapeutic goal. While the majority of inherited forms of retinal degeneration affect the outer retina, specifically the photoreceptors and retinal pigment epithelium, effective targeted delivery to this region requires invasive subretinal delivery. Our goal in this work was to evaluate two innovative approaches for increasing both the persistence of delivered nanospheres and their penetration into the outer retina while using the much less invasive intravitreal delivery method. We formulated novel hyaluronic acid nanospheres (HA-NS, 250 nm and 500 nm in diameter) conjugated to fluorescent reporters and delivered them intravitreally to the adult Balb/C mouse retina. They exhibited persistence in the vitreous and along the inner limiting membrane (ILM) for up to 30 days (longest timepoint examined) but little retinal penetration. We thus evaluated the ability of the small molecule, sulfotyrosine, to disrupt the ILM, and found that 3.2 µg/µL sulfotyrosine led to significant improvement in delivery to the outer retina following intravitreal injections without causing retinal inflammation, degeneration, or loss of function. Co-delivery of sulfotyrosine and HA-NS led to robust improvements in penetration of HA-NS into the retina and accumulation along the interface between the photoreceptors and the retinal pigment epithelium. These exciting findings suggest that sulfotyrosine and HA-NS may be an effective strategy for outer retinal targeting after intravitreal injection.

A Two-Pronged Pulmonary Gene Delivery Strategy: A Surface-Modified Fullerene Nanoparticle and a Hypotonic Vehicle

Inhaled gene therapy poses a unique potential of curing chronic lung diseases, which are currently managed primarily by symptomatic treatments. However, it has been challenging to achieve therapeutically relevant gene transfer efficacy in the lung due to the presence of numerous biological delivery barriers. Here, we introduce a simple approach that overcomes both extracellular and cellular barriers to enhance gene transfer efficacy in the lung in vivo. We endowed tetra(piperazino)fullerene epoxide (TPFE)‐based nanoparticles with non‐adhesive surface polyethylene glycol (PEG) coatings, thereby enabling the nanoparticles to cross the airway mucus gel layer and avoid phagocytic uptake by alveolar macrophages. In parallel, we utilized a hypotonic vehicle to facilitate endocytic uptake of the PEGylated nanoparticles by lung parenchymal cells via the osmotically driven regulatory volume decrease (RVD) mechanism. We demonstrate that this two‐pronged delivery strategy provides safe, wide‐spread and high‐level transgene expression in the lungs of both healthy mice and mice with chronic lung diseases characterized by reinforced delivery barriers.

Thymus-Pineal Gland Axis: Revisiting Its Role in Human Life and Ageing

For years the thymus gland (TG) and the pineal gland (PG) have been subject of increasingly in-depth studies, but only recently a link that can associate the activities of the two organs has been identified. Considering, on the one hand, the well-known immune activity of thymus and, on the other, the increasingly emerging immunological roles of circadian oscillators and the rhythmically secreted main pineal product, melatonin, many studies aimed to analyse the possible existence of an interaction between these two systems. Moreover, data confirmed that the immune system is functionally associated with the nervous and endocrine systems determining an integrated dynamic network. In addition, recent researches showed a similar, characteristic involution process both in TG and PG. Since the second half of the 20th century, evidence led to the definition of an effectively interacting thymus-pineal axis (TG-PG axis), but much has to be done. In this sense, the aim of this review is to summarize what is actually known about this topic, focusing on the impact of the TG-PG axis on human life and ageing. We would like to give more emphasis to the implications of this dynamical interaction in a possible therapeutic strategy for human health. Moreover, we focused on all the products of TG and PG in order to collect what is known about the role of peptides other than melatonin. The results available today are often unclear and not linear. These peptides have not been well studied and defined over the years. In this review we hope to awake the interest of the scientific community in them and in their future pharmacological applications.

Effects of a novel roflumilast and formoterol fumarate dry powder inhaler formulation in experimental allergic asthma

In this study we aimed to develop a roflumilast (R) and formoterol fumarate (F) dry powder inhaler formulation (DPI) incorporating HPβCD by spray drying and evaluated if it attenuates the inflammatory process and improves lung function in a murine model of ovalbumin induced allergic asthma. The DPI was characterized by powder X-ray diffraction, thermal analysis, scanning electron microscopy, particle size, density, specific surface area and dynamic vapor sorption analyses. In vitro deposition studies were performed using a NGI, while transepithelial permeability and in vivo effects on lung mechanics and inflammation in a model of allergic asthma were also assessed. The R:F formulation was amorphous with high glass transition temperatures, comprised of wrinkled particles, had low bulk and tapped densities, high surface area, suitable particle size for pulmonary delivery and exhibited no recrystallization even at high relative humidities. MMAD were statistically similar of 4.22 ± 0.19 and 4.32 ± 0.13 µm for F and R, respectively. Fine particle fractions (<5 µm) were of more than 50% of the emitted dose. The R:F formulation led to reduced eosinophil infiltration and airway collagen fiber content, yielding decreased airway hyperresponsiveness. In the current asthma model, the R:F formulation combination decreased inflammation and remodeling, thus improving lung mechanics.

Nanoparticle-based thymulin gene therapy therapeutically reverses key pathology of experimental allergic asthma

Despite long-standing efforts to enhance care for chronic asthma, symptomatic treatments remain the only option to manage this highly prevalent and debilitating disease. We demonstrate that key pathology of allergic asthma can be almost completely resolved in a therapeutic manner by inhaled gene therapy. After the disease was fully and stably established, we treated mice intratracheally with a single dose of thymulin-expressing plasmids delivered via nanoparticles engineered to have a unique ability to penetrate the airway mucus barrier. Twenty days after the treatment, we found that all key pathologic features found in the asthmatic lung, including chronic inflammation, pulmonary fibrosis, and mechanical dysregulation, were normalized. We conducted tissue- and cell-based analyses to confirm that the therapeutic intervention was mediated comprehensively by anti-inflammatory and antifibrotic effects of the therapy. We believe that our findings open a new avenue for clinical development of therapeutically effective gene therapy for chronic asthma.

A New Gorilla Adenoviral Vector with Natural Lung Tropism Avoids Liver Toxicity and Is Amenable to Capsid Engineering and Vector Retargeting

In the aggregate, our mouse studies suggest that GAd is a promising gene therapy vector that utilizes lung ECs as a source of therapeutic payload production and a highly desirable toxicity profile. Further genetic engineering of the GAd capsid holds the promise of in vivo vector tropism modification and targeting.

Human adenoviruses have many attractive features for gene therapy applications. However, the high prevalence of preexisting immunity against these viruses in general populations worldwide has greatly limited their clinical utility. In addition, the most commonly used human adenovirus, human adenovirus subgroup C serotype 5 (HAd5), when systemically administered, triggers systemic inflammation and toxicity, with the liver being the most severely affected organ. Here, we evaluated the utility and safety of a new low-seroprevalence gorilla adenovirus (GAd; GC46) as a gene transfer vector in mice. Biodistribution studies revealed that systemically administered GAd had a selective and robust lung endothelial cell (EC) tropism with minimal vector expression throughout many other organs and tissues. Administration of a high dose of GAd accomplished extensive transgene expression in the lung yet elicited no detectable inflammatory histopathology in this organ. Furthermore, GAd, unlike HAd5, did not exhibit hepatotropism or induce liver inflammatory toxicity in mice, demonstrating the exceptional safety profile of the vector vis-à-vis systemic utility. We further demonstrated that the GAd capsid fiber shared the flexibility of the HAd5 equivalent for permitting genetic modification; GAd with the pan-EC-targeting ligand myeloid cell-binding peptide (MBP) incorporated in the capsid displayed a reduced lung tropism and efficiently retargeted gene expression to vascular beds in other organs.

IMPORTANCE In the aggregate, our mouse studies suggest that GAd is a promising gene therapy vector that utilizes lung ECs as a source of therapeutic payload production and a highly desirable toxicity profile. Further genetic engineering of the GAd capsid holds the promise of in vivo vector tropism modification and targeting.

Airway epithelial-targeted nanoparticles for asthma therapy

Asthma is a common chronic inflammatory disease associated with intermittent airflow obstruction caused by airway inflammation, mucus overproduction, and bronchial hyperresponsiveness. Despite current treatment and management options, a large number of patients with asthma still have poorly controlled disease and are susceptible to acute exacerbations, usually caused by a respiratory virus infection. As a result, there remains a need for novel therapies to achieve better control and prevent/treat exacerbations. Nanoparticles (NPs), including extracellular vesicles (EV) and their synthetic counterparts, have been developed for drug delivery in respiratory diseases. In the case of asthma, where airway epithelium dysfunction, including dysregulated differentiation of epithelial cells, impaired barrier, and immune response, is a driver of disease, targeting airway epithelial cells with NPs may offer opportunities to repair or reverse these dysfunctions with therapeutic interventions. EVs possess multiple advantages for airway epithelial targeting, such as their natural intrinsic cell-targeting properties and low immunogenicity. Synthetic NPs can be coated with muco-inert polymers to overcome biological barriers such as mucus and the phagocytic response of immune cells. Targeting ligands could be also added to enhance targeting specificity to epithelial cells. The review presents current understanding and advances in NP-mediated drug delivery to airway epithelium for asthma therapy. Future perspectives in this therapeutic strategy will also be discussed, including the development of novel formulations and physiologically relevant preclinical models.

Interface-Enrichment-Induced Instability and Drug-Loading-Enhanced Stability in Inhalable Delivery of Supramolecular Filaments

Filamentous microorganisms traveling in aerosol particles display enhanced deposition and retention in the lungs. Inspired by this shape-related biological effect, we report here on the use of supramolecular filaments as potential inhalable drug carriers within aerosols via jet nebulization. We found that the peptide design and supramolecular stability play a crucial role in the interfacial stability and aerosolization properties of the supramolecular filaments. Monomeric units with a positively charged C-terminus produced filaments with reduced aerosol stability, promoting morphological changes after nebulization. Conversely, having a neutral or negatively charged terminus yielded filaments with enhanced stability, where supramolecular integrity is maintained with only reduced length. Our results suggest that molecular enrichment at the air-liquid interface during nebulization is the primary factor to deplete the monomeric peptide amphiphiles in solution, accounting for the observed morphological disruption/transitions. Importantly, encapsulation of drugs and dyes within filaments notably stabilize their supramolecular structure during nebulization, and the loaded filaments exhibit a linear release profile from a nebulizer device. We envision the use of this supramolecular carrier system as an effective platform for the inhalation-based treatment of many lung diseases.

Inhalable nanotherapeutics to improve treatment efficacy for common lung diseases

Respiratory illnesses are prevalent around the world, and inhalation-based therapies provide an attractive, noninvasive means of directly delivering therapeutic agents to their site of action to improve treatment efficacy and limit adverse systemic side effects. Recent trends in medicine and nanoscience have prompted the development of inhalable nanomedicines to further enhance effectiveness, patient compliance, and quality of life for people suffering from lung cancer, chronic pulmonary diseases, and tuberculosis. Herein, we discuss recent advancements in the development of inhalable nanomaterial-based drug delivery systems and analyze several representative systems to illustrate their key design principles that can translate to improved therapeutic efficacy for prevalent respiratory diseases. This article is categorized under: Therapeutic Approaches and Drug Discovery > Nanomedicine for Respiratory Disease.

Targeted therapy in chronic diseases using nanomaterial-based drug delivery vehicles

The application of nanomedicines is increasing rapidly with the promise of targeted and efficient drug delivery. Nanomedicines address the shortcomings of conventional therapy, as evidenced by several preclinical and clinical investigations indicating site-specific drug delivery, reduced side effects, and better treatment outcome. The development of suitable and biocompatible drug delivery vehicles is a prerequisite that has been successfully achieved by using simple and functionalized liposomes, nanoparticles, hydrogels, micelles, dendrimers, and mesoporous particles. A variety of drug delivery vehicles have been established for the targeted and controlled delivery of therapeutic agents in a wide range of chronic diseases, such as diabetes, cancer, atherosclerosis, myocardial ischemia, asthma, pulmonary tuberculosis, Parkinson's disease, and Alzheimer's disease. After successful outcomes in preclinical and clinical trials, many of these drugs have been marketed for human use, such as Abraxane®, Caelyx®, Mepact®, Myocet®, Emend®, and Rapamune®. Apart from drugs/compounds, novel therapeutic agents, such as peptides, nucleic acids (DNA and RNA), and genes have also shown potential to be used as nanomedicines for the treatment of several chronic ailments. However, a large number of extensive clinical trials are still needed to ensure the short-term and long-term effects of nanomedicines in humans. This review discusses the advantages of various drug delivery vehicles for better understanding of their utility in terms of current medical needs. Furthermore, the application of a wide range of nanomedicines is also described in the context of major chronic diseases.

PEGylated enhanced cell penetrating peptide nanoparticles for lung gene therapy

The lung remains an attractive target for the gene therapy of monogenetic diseases such as cystic fibrosis (CF). Despite over 27 clinical trials, there are still very few gene therapy vectors that have shown any improvement in lung function; highlighting the need to develop formulations with improved gene transfer potency and the desirable physiochemical characteristics for efficacious therapy. Herein, we introduce a novel cell penetrating peptide (CPP)-based non-viral vector that utilises glycosaminoglycan (GAG)-binding enhanced transduction (GET) for highly efficient gene transfer. GET peptides couple directly with DNA through electrostatic interactions to form nanoparticles (NPs). In order to adapt the GET peptide for efficient in vivo delivery, we engineered PEGylated versions of the peptide and employed a strategy to form DNA NPs with different densities of PEG coatings. We were able to identify candidate formulations (PEGylation rates ≥40%) that shielded the positively charged surface of particles, maintained colloidal stability in bronchoalveolar lavage fluid (BALF) and retained gene transfer activity in human bronchial epithelial cell lines and precision cut lung slices (PCLS) in vitro. Using multiple particle tracking (MPT) technology, we demonstrated that PEG-GET complexes were able to navigate the mucus mesh and diffuse rapidly through patient CF sputum samples ex vivo. When tested in mouse lung models in vivo, PEGylated particles demonstrated superior biodistribution, improved safety profiles and efficient gene transfer of a reporter luciferase plasmid compared to non-PEGylated complexes. Furthermore, gene expression was significantly enhanced in comparison to polyethylenimine (PEI), a non-viral gene carrier that has been widely tested in pre-clinical settings. This work describes an innovative approach that combines novel GET peptides for enhanced transfection with a tuneable PEG coating for efficacious lung gene therapy.

Nanoformulated ABT-199 to effectively target Bcl-2 at mitochondrial membrane alleviates airway inflammation by inducing apoptosis

Elimination of airway inflammatory cells is essential for asthma control. As Bcl-2 protein is highly expressed on the mitochondrial outer membrane in inflammatory cells, we chose a Bcl-2 inhibitor, ABT-199, which can inhibit airway inflammation and airway hyperresponsiveness by inducing inflammatory cell apoptosis. Herein, we synthesized a pH-sensitive nanoformulated Bcl-2 inhibitor (Nf-ABT-199) that could specifically deliver ABT-199 to the mitochondria of bronchial inflammatory cells. The proof-of-concept study of an inflammatory cell mitochondria-targeted therapy using Nf-ABT-199 was validated in a mouse model of allergic asthma. Nf-ABT-199 was proven to significantly alleviate airway inflammation by effectively inducing eosinophil apoptosis and inhibiting both inflammatory cell infiltration and mucus hypersecretion. In addition, the nanocarrier or Nf-ABT-199 showed no obvious influence on cell viability, airway epithelial barrier and liver function, implying excellent biocompatibility and with non-toxic effect. The nanoformulated Bcl-2 inhibitor Nf-ABT-199 accumulates in the mitochondria of inflammatory cells and efficiently alleviates allergic asthma.

New perspectives in nanotherapeutics for chronic respiratory diseases

According to the World Health Organization (WHO), hundreds of millions of people of all ages and in all countries suffer from chronic respiratory diseases, with particular negative consequences such as poor health-related quality of life, impaired work productivity, and limitations in the activities of daily living. Chronic obstructive pulmonary disease, asthma, occupational lung diseases (such as silicosis), cystic fibrosis, and pulmonary arterial hypertension are the most common of these diseases, and none of them are curable with current therapies. The advent of nanotechnology holds great therapeutic promise for respiratory conditions, because non-viral vectors are able to overcome the mucus and lung remodeling barriers, increasing pharmacologic and therapeutic potency. It has been demonstrated that the extent of pulmonary nanoparticle uptake depends not only on the physical and chemical features of nanoparticles themselves, but also on the health status of the organism; thus, the huge diversity in nanotechnology could revolutionize medicine, but safety assessment is a challenging task. Within this context, the present review discusses some of the major new perspectives in nanotherapeutics for lung disease and highlights some of the most recent studies in the field.

Human adipose tissue mesenchymal stromal cells and their extracellular vesicles act differentially on lung mechanics and inflammation in experimental allergic asthma

Background

Asthma is a chronic inflammatory disease that can be difficult to treat due to its complex pathophysiology. Most current drugs focus on controlling the inflammatory process, but are unable to revert the changes of tissue remodeling. Human mesenchymal stromal cells (MSCs) are effective at reducing inflammation and tissue remodeling; nevertheless, no study has evaluated the therapeutic effects of extracellular vesicles (EVs) obtained from human adipose tissue-derived MSCs (AD-MSC) on established airway remodeling in experimental allergic asthma.

Methods

C57BL/6 female mice were sensitized and challenged with ovalbumin (OVA). Control (CTRL) animals received saline solution using the same protocol. One day after the last challenge, each group received saline, 10⁵ human AD-MSCs, or EVs (released by 10⁵ AD-MSCs). Seven days after treatment, animals were anesthetized for lung function assessment and subsequently euthanized. Bronchoalveolar lavage fluid (BALF), lungs, thymus, and mediastinal lymph nodes were harvested for analysis of inflammation. Collagen fiber content of airways and lung parenchyma were also evaluated.

Results

In OVA animals, AD-MSCs and EVs acted differently on static lung elastance and on BALF regulatory T cells, CD3⁺CD4⁺ T cells, and pro-inflammatory mediators (interleukin [IL]-4, IL-5, IL-13, and eotaxin), but similarly reduced eosinophils in lung tissue, collagen fiber content in airways and lung parenchyma, levels of transforming growth factor-β in lung tissue, and CD3⁺CD4⁺ T cell counts in the thymus. No significant changes were observed in total cell count or percentage of CD3⁺CD4⁺ T cells in the mediastinal lymph nodes.

Conclusions

In this immunocompetent mouse model of allergic asthma, human AD-MSCs and EVs effectively reduced eosinophil counts in lung tissue and BALF and modulated airway remodeling, but their effects on T cells differed in lung and thymus. EVs may hold promise for asthma; however, further studies are required to elucidate the different mechanisms of action of AD-MSCs versus their EVs.

A new adenovector system for implementing thymulin gene therapy for inflammatory disorders

Thymulin is a thymic peptide possessing anti-inflammatory effects. In order to manipulate thymulin expression in gene therapy studies, we built a bidirectional regulatable two-vector Tet-Off system and the corresponding control system. The experimental two-vector system, ETV, consists of a recombinant adenovector (RAd) harboring an expression cassette centered on a Tet-Off bidirectional promoter flanked by a synthetic gene for thymulin and the gene for humanized Green Fluorescent Protein (hGFP). The second adenovector of this system, RAd-tTA, constitutively expresses the regulatory protein tTA. When cells are co-transduced by the two adenovector components, tTA activates the bidirectional promoter and both transgenes are expressed. In the presence of the antibiotic doxycycline (DOX) transgene expression is deactivated. The control two-vector system, termed CTV, is similar to ETV but only expresses hGFP. In CHO-K1, BHK, and C2C12 cells, ETV and CTV induced a dose-dependent hGFP expression. In CHO-K1 cells, transgene expression was almost completely inhibited by DOX (1mg/ml). After intracerebroventricular injection of ETV in rats, thymulin levels increased significantly in the cerebrospinal fluid and there was high hGFP expression in the ependymal cell layer. When injected intramuscularly the ETV system induced a progressive increase in serum thymulin levels, which were inhibited when DOX was added to the drinking water. We conclude that our regulatable two-adenovector system is an effective molecular tool for implementing short and long-term anti-inflammatory thymulin gene therapy in animal models of acute or chronic inflammation.

Bone Marrow, Adipose, and Lung Tissue-Derived Murine Mesenchymal Stromal Cells Release Different Mediators and Differentially Affect Airway and Lung Parenchyma in Experimental Asthma

Mesenchymal stromal cells (MSCs) from different sources have differential effects on lung injury. To compare the effects of murine MSCs from bone marrow (BM), adipose tissue (AD), and lung tissue (LUNG) on inflammatory and remodeling processes in experimental allergic asthma, female C57BL/6 mice were sensitized and challenged with ovalbumin (OVA) or saline (C). Twenty‐four hours after the last challenge, mice received either saline (50 µl, SAL), BM‐MSCs, AD‐MSCs, or LUNG‐MSCs (10⁵ cells per mouse in 50 µl total volume) intratracheally. At 1 week, BM‐MSCs produced significantly greater reductions in resistive and viscoelastic pressures, bronchoconstriction index, collagen fiber content in lung parenchyma (but not airways), eosinophil infiltration, and levels of interleukin (IL)‐4, IL‐13, transforming growth factor (TGF)‐β, and vascular endothelial growth factor (VEGF) in lung homogenates compared to AD‐MSCs and LUNG‐MSCs. Only BM‐MSCs increased IL‐10 and interferon (IFN)‐γ in lung tissue. In parallel in vitro experiments, BM‐MSCs increased M2 macrophage polarization, whereas AD‐MSCs and LUNG‐MSCs had higher baseline levels of IL‐4, insulin‐like growth factor (IGF), and VEGF secretion. Exposure of MSCs to serum specimens obtained from asthmatic mice promoted reductions in secretion of these mediators, particularly in BM‐MSCs. Intratracheally administered BM‐MSCs, AD‐MSCs, and LUNG‐MSCs were differentially effective at reducing airway inflammation and remodeling and improving lung function in the current model of allergic asthma. In conclusion, intratracheal administration of MSCs from BM, AD, and LUNG were differentially effective at reducing airway inflammation and remodeling and improving lung function comparably reduced inflammation and fibrogenesis in this asthma model. However, altered lung mechanics and lung remodeling responded better to BM‐MSCs than to AD‐MSCs or LUNG‐MSCs. Moreover, each type of MSC was differentially affected in a surrogate in vitro model of the in vivo lung environment. Stem Cells Translational Medicine2017;6:1557–1567

In vivo fate tracking of degradable nanoparticles for lung gene transfer using PET and Ĉerenkov imaging

Nanoparticles (NPs) play expanding roles in biomedical applications including imaging and therapy, however, their long-term fate and clearance profiles have yet to be fully characterized in vivo. NP delivery via the airway is particularly challenging, as the clearance may be inefficient and lung immune responses complex. Thus, specific material design is required for cargo delivery and quantitative, noninvasive methods are needed to characterize NP pharmacokinetics. Here, biocompatible poly(acrylamidoethylamine)-b-poly(dl-lactide) block copolymer-based degradable, cationic, shell-cross-linked knedel-like NPs (Dg-cSCKs) were employed to transfect plasmid DNA. Radioactive and optical beacons were attached to monitor biodistribution and imaging. The preferential release of cargo in acidic conditions provided enhanced transfection efficiency compared to non-degradable counterparts. In vivo gene transfer to the lung was correlated with NP pharmacokinetics by radiolabeling Dg-cSCKs and performing quantitative biodistribution with parallel positron emission tomography and Čerenkov imaging. Quantitation of imaging over 14 days corresponded with the pharmacokinetics of NP movement from the lung to gastrointestinal and renal routes, consistent with predicted degradation and excretion. This ability to noninvasively and accurately track NP fate highlights the advantage of incorporating multifunctionality into particle design.

Barriers to inhaled gene therapy of obstructive lung diseases: A review

Knowledge of genetic origins of obstructive lung diseases has made inhaled gene therapy an attractive alternative to the current standards of care that are limited to managing disease symptoms. Initial lung gene therapy clinical trials occurred in the early 1990s following the discovery of the genetic defect responsible for cystic fibrosis (CF), a monogenic disorder. However, despite over two decades of intensive effort, gene therapy has yet to help patients with CF or any other obstructive lung disease. The slow progress is due in part to poor understanding of the biological barriers to inhaled gene therapy. Encouragingly, clinical trials have shown that inhaled gene therapy with various viral vectors and non-viral gene vectors is well tolerated by patients, and continued research has provided valuable lessons and resources that may lead to future success of this therapeutic strategy. In this review, we first introduce representative obstructive lung diseases and examine limitations of currently available therapeutic options. We then review key components for successful execution of inhaled gene therapy, including gene delivery systems, primary physiological barriers and strategies to overcome them, and advances in preclinical disease models with which the most promising systems may be identified for human clinical trials.

Nanoparticles coated with high molecular weight PEG penetrate mucus and provide uniform vaginal and colorectal distribution in vivo

AIM

We previously reported that nanoparticles (NPs) coated with 10 kDa PEG were mucoadhesive. Here, we demonstrate that by increasing the surface density, PEG with molecular weight (MW) as high as 40 kDa can be used as a mucoinert NP surface coating.

MATERIALS & METHODS

We compared two sets of reaction conditions for coating model polystyrene NPs with 10 kDa PEG and used optimized conditions to coat NPs with PEG as high as 40 kDa in MW. We then characterized NP transport in human cervicovaginal mucus ex vivo. We further administered PEG-coated NPs to the mouse cervicovaginal tract and colorectum to assess mucosal distribution in vivo.

RESULTS & CONCLUSION

We demonstrate here that PEG with MW as high as 40 kDa can be densely grafted to the surface of NP to prevent interactions with mucus. NP coated with 10-40 kDa PEG rapidly diffused through human cervicovaginal mucus ex vivo, and uniformly lined the mouse colorectal and vaginal epithelium in vivo.

Non-viral gene therapy: Gains and challenges of non-invasive administration methods

Gene therapy is becoming an influential part of the rapidly increasing armamentarium of biopharmaceuticals for improving health and combating diseases. Currently, three gene therapy treatments are approved by regulatory agencies. While these treatments utilize viral vectors, non-viral alternative technologies are also being developed to improve the safety profile and manufacturability of gene carrier formulations. We present an overview of gene-based therapies focusing on non-viral gene delivery systems and the genetic therapeutic tools that will further revolutionize medical treatment with primary focus on the range and development of non-invasive delivery systems for dermal, transdermal, ocular and pulmonary administrations and perspectives on other administration methods such as intranasal, oral, buccal, vaginal, rectal and otic delivery.

Nanocomplexes for gene therapy of respiratory diseases: Targeting and overcoming the mucus barrier

Gene therapy, i.e. the delivery and expression of therapeutic genes, holds great promise for congenital and acquired respiratory diseases. Non-viral vectors are less toxic and immunogenic than viral vectors, although they are characterized by lower efficiency. However, they have to overcome many barriers, including inflammatory and immune mediators and cells. The respiratory and airway epithelial cells, the main target of these vectors, are coated with a layer of mucus, which hampers the effective reaching of gene therapy vectors carrying either plasmid DNA or small interfering RNA. This barrier is thicker in many lung diseases, such as cystic fibrosis. This review summarizes the most important advancements in the field of non-viral vectors that have been achieved with the use of nanoparticulate (NP) systems, composed either of polymers or lipids, in the lung gene delivery. In particular, different strategies of targeting of respiratory and airway lung cells will be described. Then, we will focus on the two approaches that attempt to overcome the mucus barrier: coating of the nanoparticulate system with poly(ethylene glycol) and treatment with mucolytics. Our conclusions are: 1) Ligand and physical targeting can direct therapeutic gene expression in specific cell types in the respiratory tract; 2) Mucopenetrating NPs are endowed with promising features to be useful in treating respiratory diseases and should be now advanced in pre-clinical trials. Finally, we discuss the development of such polymer- and lipid-based NPs in the context of in vitro and in vivo disease models, such as lung cancer, as well as in clinical trials.

Therapeutic and safety considerations of nanoparticle-mediated drug delivery in pregnancy

Advances in nanotechnology have resulted in the design of effective, safe and tissue-selective nanocarriers for delivering therapeutics to treat malignancies, infections and other diseases. In pregnancy, nanoparticle-based drug formulations could have the potential to selectively target either the placenta and/or fetus, enabling ‘fetal-friendly’ drugs to be administered in pregnancy with minimal risk of off-target effects. A considerable amount of research has been carried out on maternal-placental-fetal nanoparticle uptake, transfer and toxicity using rodent and ex vivo models. However, the development of placental targeting strategies and the therapeutic evaluation of nanoformulations in pregnancy remains in its infancy. While some promising avenues are currently under investigation, much work is needed to bring the advantages of nanoparticle-based drug therapy in pregnancy to clinical reality.

Modulation of inflammatory response in mice with severe autoimmune disease by thymic peptide thymulin and an inhibitor of NF-kappaB signalling

To investigate some cellular and molecular aspects of the autoimmune response and anti-inflammatory efficiency of potential therapeutic agents in a severe form of experimental autoimmune encephalomyelitis (sEAE), an inhibitor of NF-kappaB signalling, IKK Inhibitor XII, and/or thymic peptide thymulin, were injected intraperitoneally at 1.8 and 0.15mg/kg e.o.d, respectively, to C57BL/6 mice immunized with myelin oligodendrocyte glycoprotein and several adjuvants. The immunization induced high lethality in three weeks. The biphasic cytokine response observed in earlier and delayed phases was attributed to the activity of Th1 and Th17 cells, respectively. Phosphorylation of RelA protein from the NF-kappaB family increased during the earlier phase and decreased in the delayed phase. SAPK/JNK signalling protein and heat shock protein Hsp72 significantly increased in lymphocytes. Both the IKK Inhibitor XII and thymulin reduced disease severity, attenuated immune imbalance, and increased mouse life-span. Co-administration of the agents produced no additive effect. Both the inhibitor and thymulin reduced the Th1 response but not the Th17 response. Therefore, RelA-associated Th1 activation and RelA-independent Th17 activation occurred in sEAE. Thymulin and the inhibitor demonstrate similar patterns of activity, potentially through the RelA pathway inhibition, resulting in a partial therapeutic effect on the animals' health status.

Effects of bone marrow mononuclear cells from healthy or ovalbumin-induced lung inflammation donors on recipient allergic asthma mice

Introduction

Asthma is characterized by a chronic inflammatory process which may lead to several changes in bone marrow cell composition. We hypothesized that bone marrow mononuclear cells (BMMCs) obtained from ovalbumin (OVA)-induced lung inflammation mice may promote different effects compared to BMMCs from healthy donors in a model of allergic asthma.

Methods

C57BL/6 mice were randomly assigned to two groups. In the OVA group, mice were sensitized and challenged with ovalbumin, while healthy animals (control group) received saline using the same protocol. BMMCs were analyzed by flow cytometry 24 hours after the last challenge. After BMMC characterization, another group of OVA mice were further randomized into three subgroups to receive intratracheal saline (BMMC-SAL), BMMCs from control or BMMCs from OVA mice (BMMC-Control and BMMC-OVA, respectively; 2x10⁶ cells/mouse), 24 hours after the last challenge.

Results

BMMC-OVA exhibited an increased percentage of eosinophils, monocytes and hematopoietic precursors, while mesenchymal stem cells decreased, as compared with BMMC-Control. BMMCs from both donor groups reduced airway resistance, alveolar collapse, bronchoconstriction index, eosinophil infiltration, collagen fiber content in alveolar septa and levels of interleukin (IL)-4, IL-5, IL-13, interferon-γ, transforming growth factor-β, and vascular endothelial growth factor in lung homogenates. However, the benefits of BMMCs were significantly more pronounced when cells were obtained from control donors.

Conclusion

Both BMMC-Control and BMMC-OVA reduced the inflammatory and remodeling processes; nevertheless, BMMC-Control led to a greater improvement in lung morphofunction, which may be due to different BMMC composition and/or properties.