Identification of Factors of Importance for Spray Drying of Small Interfering RNA-Loaded Lipidoid-Polymer Hybrid Nanoparticles for Inhalation

Facilitating the use of the target product profile in academic research: a systematic review

BACKGROUND

The Target Product Profile (TPP) is a tool used in industry to guide development strategies by addressing user needs and fostering effective communication among stakeholders. However, they are not frequently used in academic research, where they may be equally useful. This systematic review aims to extract the features of accessible TPPs, to identify commonalities and facilitate their integration in academic research methodology.

METHODS

We searched peer-reviewed papers published in English developing TPPs for different products and health conditions in four biomedical databases. Interrater agreement, computed on random abstract and paper sets (Cohen's Kappa; percentage agreement with zero tolerance) was > 0.91. We interviewed experts from industry contexts to gain insight on the process of TPP development, and extracted general and specific features on TPP use and structure.

RESULTS

138 papers were eligible for data extraction. Of them, 92% (n = 128) developed a new TPP, with 41.3% (n = 57) focusing on therapeutics. The addressed disease categories were diverse; the largest (47.1%, n = 65) was infectious diseases. Only one TPP was identified for several fields, including global priorities like dementia. Our analyses found that 56.5% of papers (n = 78) was authored by academics, and 57.8% of TPPs (n = 80) featured one threshold level of product performance. The number of TPP features varied widely across and within product types (n = 3-44). Common features included purpose/context of use, shelf life for drug stability and validation aspects. Most papers did not describe the methods used to develop the TPP. We identified aspects to be taken into account to build and report TPPs, as a starting point for more focused initiatives guiding use by academics.

DISCUSSION

TPPs are used in academic research mostly for infectious diseases and have heterogeneous features. Our extraction of key features and common structures helps to understand the tool and widen its use in academia. This is of particular relevance for areas of notable unmet needs, like dementia. Collaboration between stakeholders is key for innovation. Tools to streamline communication such as TPPs would support the development of products and services in academia as well as industry.

Recent Developments in Aerosol Pulmonary Drug Delivery: New Technologies, New Cargos, and New Targets

There is nothing like a global pandemic to motivate the need for improved respiratory treatments and mucosal vaccines. Stimulated by the COVID-19 pandemic, pulmonary aerosol drug delivery has seen a flourish of activity, building on the prior decades of innovation in particle engineering, inhaler device technologies, and clinical understanding. As such, the field has expanded into new directions and is working toward the efficient delivery of increasingly complex cargos to address a wider range of respiratory diseases. This review seeks to highlight recent innovations in approaches to personalize inhalation drug delivery, deliver complex cargos, and diversify the targets treated and prevented through pulmonary drug delivery. We aim to inform readers of the emerging efforts within the field and predict where future breakthroughs are expected to impact the treatment of respiratory diseases.

Spray-Dried Nanolipid Powders for Pulmonary Drug Delivery: A Comprehensive Mini Review

Lung diseases have received great attention in the past years because they contribute approximately one-third of the total global mortality. Pulmonary drug delivery is regarded as one of the most appealing routes to treat lung diseases. It addresses numerous drawbacks linked to traditional dosage forms. It presents notable features, such as, for example, a non-invasive route, localized lung drug delivery, low enzymatic activity, low drug degradation, higher patient compliance, and avoiding first-pass metabolism. Therefore, the pulmonary route is commonly explored for delivering drugs both locally and systemically. Inhalable nanocarrier powders, especially, lipid nanoparticle formulations, including solid-lipid and nanostructured-lipid nanocarriers, are attracting considerable interest in addressing respiratory diseases thanks to their significant advantages, including deep lung deposition, biocompatibility, biodegradability, mucoadhesion, and controlled drug released. Spray drying is a scalable, fast, and commercially viable technique to produce nanolipid powders. This review highlights the ideal criteria for inhalable spray-dried SLN and NLC powders for the pulmonary administration route. Additionally, the most promising inhalation devices, known as dry powder inhalers (DPIs) for the pulmonary delivery of nanolipid powder-based medications, and pulmonary applications of SLN and NLC powders for treating chronic lung conditions, are considered.

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.

Research Progress on Liposome Pulmonary Delivery of Mycobacterium tuberculosis Nucleic Acid Vaccine and Its Mechanism of Action

Traditional vaccines have played an important role in the prevention and treatment of infectious diseases, but they still have problems such as low immunogenicity, poor stability, and difficulty in inducing lasting immune responses. In recent years, the nucleic acid vaccine has emerged as a relatively cheap and safe new vaccine. Compared with traditional vaccines, nucleic acid vaccine has some unique advantages, such as easy production and storage, scalability, and consistency between batches. However, the direct administration of naked nucleic acid vaccine is not ideal, and safer and more effective vaccine delivery systems are needed. With the rapid development of nanocarrier technology, the combination of gene therapy and nanodelivery systems has broadened the therapeutic application of molecular biology and the medical application of biological nanomaterials. Nanoparticles can be used as potential drug-delivery vehicles for the treatment of hereditary and infectious diseases. In addition, due to the advantages of lung immunity, such as rapid onset of action, good efficacy, and reduced adverse reactions, pulmonary delivery of nucleic acid vaccine has become a hot spot in the field of research. In recent years, lipid nanocarriers have become safe, efficient, and ideal materials for vaccine delivery due to their unique physical and chemical properties, which can effectively reduce the toxic side effects of drugs and achieve the effect of slow release and controlled release, and there have been a large number of studies using lipid nanocarriers to efficiently deliver target components into the body. Based on the delivery of tuberculosis (TB) nucleic acid vaccine by lipid carrier, this article systematically reviews the advantages and mechanism of liposomes as a nucleic acid vaccine delivery carrier, so as to lay a solid foundation for the faster and more effective development of new anti-TB vaccine delivery systems in the future.

Evaluation of the effects of storage conditions on spray-dried siRNA-LNPs before and after subsequent drying

In an ideal world, pharmaceutical drugs would have infinite shelf life, no susceptibility to degradation, chemical reactions or loss of efficacy. In reality, these processes occur, however, making it desirable to extend a drugs' shelf life. Nucleic acid-based drugs are most commonly stored as aqueous suspension where they are vulnerable to microbial growth and degradation processes. Drying procedures, such as lyophilization and spray drying, help to reduce the products' residual moisture while increasing the products' shelf life and stability. The present study was designed to evaluate 90 days of storage of spray-dried siRNA-lipid nanoparticles (LNPs) at 4 °C and 25 °C. An updated Onpattro® composition modified with a positively charged helper lipid was used as the LNP carrier system. In an attempt to further reduce the residual moisture of our previously reported formulations, all LNP samples were subjected to a secondary drying step in the spray drying tower for 20 min. The measurement of physicochemical properties of spray-dried and subsequently dried LNPs resulted in sizes of 180 nm, PDI values of 0.1-0.15 and zeta potentials of + 3 mV. Spray drying resulted in residual moisture levels of 3.6-4 % and was reduced by subsequent drying to 2.8-3.1 %. Aerodynamic properties after storage showed discrepancies depending on the storage conditions. MMADs remained at 2.8 µm when stored at 4 °C, whereas an increase to 5 µm at 25 °C was observed. Subsequent drying led to sizes of 3.6-3.8 µm, independent of the storage conditions. Spray-dried LNPs maintained bioactivity resulting in > 95 % protein downregulation and confirming the lack of cytotoxic effects in a lung adenocarcinoma cell line. Furthermore, the spray-dried and subsequently dried LNPs stored for 3 months at 4 °C and 25 °C achieved up to 50 % gene silencing of the house-keeping gene GAPDH after deposition on the mucus layer of Calu-3 cells. This study confirms the stability of spray-dried and subsequently dried LNPs over at least 90 days at 4 °C and 25 °C emphasizing the potential of dry powder inhalation of RNA-loaded LNPs as a therapy option for pulmonary diseases.

RNAi therapies: Expanding applications for extrahepatic diseases and overcoming delivery challenges

The era of RNA medicine has become a reality with the success of messenger RNA (mRNA) vaccines against COVID-19 and the approval of several RNA interference (RNAi) agents in recent years. Particularly, therapeutics based on RNAi offer the promise of targeting intractable and previously undruggable disease genes. Recent advances have focused in developing delivery systems to enhance the poor cellular uptake and insufficient pharmacokinetic properties of RNAi therapeutics and thereby improve its efficacy and safety. However, such approach has been mainly achieved via lipid nanoparticles (LNPs) or chemical conjugation with N-Acetylgalactosamine (GalNAc), thus current RNAi therapy has been limited to liver diseases, most likely to encounter liver-targeting limitations. Hence, there is a huge unmet medical need for intense evolution of RNAi therapeutics delivery systems to target extrahepatic tissues and ultimately extend their indications for treating various intractable diseases. In this review, challenges of delivering RNAi therapeutics to tumors and major organs are discussed, as well as their transition to clinical trials. This review also highlights innovative and promising preclinical RNAi-based delivery platforms for the treatment of extrahepatic diseases.

Advancing Treatment Strategies: A Comprehensive Review of Drug Delivery Innovations for Chronic Inflammatory Respiratory Diseases

Chronic inflammatory respiratory diseases, such as asthma, chronic obstructive pulmonary disease (COPD), and cystic fibrosis, present ongoing challenges in terms of effective treatment and management. These diseases are characterized by persistent inflammation in the airways, leading to structural changes and compromised lung function. There are several treatments available for them, such as bronchodilators, immunomodulators, and oxygen therapy. However, there are still some shortcomings in the effectiveness and side effects of drugs. To achieve optimal therapeutic outcomes while minimizing systemic side effects, targeted therapies and precise drug delivery systems are crucial to the management of these diseases. This comprehensive review focuses on the role of drug delivery systems in chronic inflammatory respiratory diseases, particularly nanoparticle-based drug delivery systems, inhaled corticosteroids (ICSs), novel biologicals, gene therapy, and personalized medicine. By examining the latest advancements and strategies in these areas, we aim to provide a thorough understanding of the current landscape and future prospects for improving treatment outcomes in these challenging conditions.

Recent Advances in the Microencapsulation of Essential Oils, Lipids, and Compound Lipids through Spray Drying: A Review

In recent decades, the microcapsules of lipids, compound lipids, and essential oils, have found numerous potential practical applications in food, textiles, agricultural products, as well as pharmaceuticals. This article discusses the encapsulation of fat-soluble vitamins, essential oils, polyunsaturated fatty acids, and structured lipids. Consequently, the compiled information establishes the criteria to better select encapsulating agents as well as combinations of encapsulating agents best suited to the types of active ingredient to be encapsulated. This review shows a trend towards applications in food and pharmacology as well as the increase in research related to microencapsulation by the spray drying of vitamins A and E, as well as fish oil, thanks to its contribution of omega 3 and omega 6. There is also an increase in articles in which spray drying is combined with other encapsulation techniques, or modifications to the conventional spray drying system.

Shaping the future from the small scale: dry powder inhalation of CRISPR-Cas9 lipid nanoparticles for the treatment of lung diseases

INTRODUCTION

Most lung diseases are serious conditions resulting from genetic and environmental causes associated with high mortality and severe symptoms. Currently, treatments available have a palliative effect and many targets are still considered undruggable. Gene therapy stands as an attractive approach to offering innovative therapeutic solutions. CRISPRCas9 has established a remarkable potential for genome editing with high selectivity to targeted mutations. To ensure high efficacy with minimum systemic exposure, the delivery and administration route are key components that must be investigated.

AREAS COVERED

This review is focused on the delivery of CRISPRCas9 to the lungs, taking advantage of lipid nanoparticles (LNPs), the most clinically advanced nucleic acid carriers. We also aim to highlight the benefits of pulmonary administration as a local delivery route and the use of spray drying to prepare stable nucleic-acid-based dry powder formulations that can overcome multiple lung barriers.

EXPERT OPINION

Exploring the pulmonary administration to deliver CRISPRCas9 loaded in LNPs as a dry powder increases the chances to achieve high efficacy and reduced adverse effects. CRISPRCas9 loaded in LNP-embedded microparticles has not yet been reported in the literature but has the potential to reach and accumulate in target cells in the lung, thus, enhancing overall efficacy and safety.

Elucidating the nanostructure of small interfering RNA-loaded lipidoid-polymer hybrid nanoparticles

We analyzed the structural and material properties of small interfering RNA (siRNA)-loaded lipid-polymer hybrid nanoparticles (LPNs) containing ionizable lipidoid and poly(dl-lactic-co-glycolic acid) (PLGA) using small-angle X-ray scattering, cryogenic transmission electron microscopy, polarized light microscopy, the Langmuir monolayer methodology, differential scanning calorimetry, and attenuated total reflectance Fourier-transform infrared (ATR-FTIR) spectroscopy. Scattering analyses showed that bulk lipidoid self-assemble into lamellar structures with a d-spacing of 38 Å, whereas lipidoid-siRNA lipoplexes display an in-plane lateral organization of siRNA in between lipidoid bilayers with a repeat distance of approximately 55 Å. The siRNA-loaded LPNs adopted a core-shell structure with an interaxial alignment of siRNA between lipidoid shell bilayers. Langmuir monolayer experiments showed a distinct interaction between the lipidoid headgroups and siRNA, which was dependent on buffer subphase pH. Thermal analyses suggested that PLGA and lipidoid interact, which was evident from a shift in the phase transition temperature of lipidoid, and the thermotropic phase behavior of lipidoid was affected by inclusion of siRNA. ATR-FTIR data confirmed the shift or disappearance of characteristic absorption bands of siRNA after lipidoid binding. In conclusion, siRNA-loaded LPNs display a core-shell structure, wherein the polymeric core functions as a colloid matrix support for siRNA-loaded lipidoid shell layers.

Potential of siRNA in COVID-19 therapy: Emphasis on in silico design and nanoparticles based delivery

Small interfering RNA (siRNA)-mediated mRNA degradation approach have imparted its eminence against several difficult-to-treat genetic disorders and other allied diseases. Viral outbreaks and resulting pandemics have repeatedly threatened public health and questioned human preparedness at the forefront of drug design and biomedical readiness. During the recent pandemic caused by the SARS-CoV-2, mRNA-based vaccination strategies have paved the way for a new era of RNA therapeutics. RNA Interference (RNAi) based approach using small interfering RNA may complement clinical management of the COVID-19. RNA Interference approach will primarily work by restricting the synthesis of the proteins required for viral replication, thereby hampering viral cellular entry and trafficking by targeting host as well as protein factors. Despite promising benefits, the stability of small interfering RNA in the physiological environment is of grave concern as well as site-directed targeted delivery and evasion of the immune system require immediate attention. In this regard, nanotechnology offers viable solutions for these challenges. The review highlights the potential of small interfering RNAs targeted toward specific regions of the viral genome and the features of nanoformulations necessary for the entrapment and delivery of small interfering RNAs. In silico design of small interfering RNA for different variants of SARS-CoV-2 has been discussed. Various nanoparticles as promising carriers of small interfering RNAs along with their salient properties, including surface functionalization, are summarized. This review will help tackle the real-world challenges encountered by the in vivo delivery of small interfering RNAs, ensuring a safe, stable, and readily available drug candidate for efficient management of SARS-CoV-2 in the future.

Microfluidic production of mRNA-loaded lipid nanoparticles for vaccine applications

INTRODUCTION

During past years, lipid nanoparticles (LNPs) have emerged as promising carriers for RNA delivery, with several clinical trials focusing on both infectious diseases and cancer. More recently, the success of messenger RNA (mRNA) vaccines for the treatment of severe diseases such as acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is partially justified by the development of LNPs encapsulating mRNA for efficient cytosolic delivery.

AREAS COVERED

This review examines the production and formulation of LNPs by using microfluidic devices, the status of mRNA-loaded LNPs therapeutics and explores spray drying process, as a promising dehydration process to enhance LNP stability and provide alternative administration routes.

EXPERT OPINION

Microfluidic techniques for preparation of LNPs based on organic solvent injection method promotes the generation of stable, uniform, and monodispersed nanoparticles enabling higher encapsulation efficiency. In particular, the application of microfluidics for the fabrication of mRNA-loaded LNPs is based on rapid mixing of small volumes of ethanol solution containing lipids and aqueous solution containing mRNA. Control of operating parameters and formulation has enabled the optimization of nanoparticle physicochemical characteristics and encapsulation efficiency.

Can pulmonary RNA delivery improve our pandemic preparedness?

The coronavirus pandemic has changed our perception of RNA medicines, and RNA vaccines have revolutionized our pandemic preparedness. But are we indeed prepared for the next variant or the next emerging virus? How can we prepare? And what does the role of inhaled antiviral RNA play in this regard? When the pandemic started, I rerouted much of the ongoing inhaled RNA delivery research in my group towards the inhibition and treatment of respiratory viral infections. Two years later, I have taken the literature, past and ongoing clinical trials into consideration and have gained new insights based on our collaborative research which I will discuss in this oration.

Leucine improves the aerosol performance of dry powder inhaler formulations of siRNA-loaded nanoparticles

Thermostable dry powder inhaler (DPI) formulations with high aerosol performance are attractive inhalable solid dosage forms for local treatment of inflammatory lung diseases. We recently demonstrated that lipidoid-polymer hybrid nanoparticles (LPNs) loaded with small interfering RNA (siRNA) directed against tumor necrosis factor alpha (TNF-α) mediate efficient intracellular siRNA delivery and reduce inflammation in vivo. Here, we show that mixtures of the stabilizing excipients trehalose (Tre) and dextran (Dex), in combination with the shell-forming dispersion enhancer leucine (Leu), stabilize TNF-α siRNA-loaded LPNs during spray drying into nanocomposite microparticles (DPI formulations), and result in DPI formulations with high aerosol performance. At low Leu content (0 to 10%, w/w), the DPI formulations were amorphous, and exhibited poor aerosol performance. When the Leu content was increased from 20 to 60% (w/w), the surface content of Leu increased from 39.2 to 68.1 mol%, and the flowability was significantly improved. Microscopy analyses suggest that the improved powder dispersibility is the result of a wrinkled surface morphology, which reduces the surface area available for interparticle interactions. Increasing the Leu content further (above 10%, w/w) did not influence the aerosol performance, and the aerosol yield was maximal at 30-40% Leu (w/w). Formulations containing 40% Leu and a Tre:Dex ratio of 10:90 (w/w) displayed a high fine particle fraction and aerosol properties suitable for inhalation. The chemical integrity of TNF-α siRNA was preserved in the solid state, and biodistribution studies in mice showed that pulmonary administration of DPI formulations with high aerosol performance resulted in homogenous deep lung deposition. Our results demonstrate that at optimal ratios, ternary excipient mixtures of Leu, Tre and Dex protect TNF-α siRNA-loaded LPNs during spray drying. Hence, this study shows that microparticles with an amorphous Tre/Dex matrix and a crystalline Leu shell are required for stabilizing the nanocomposite LPNs in the solid state, and for ensuring aerosol properties suitable for inhalation.

Stability investigation of air-dried olive ribo nucleic acids for metavirome studies

BACKGROUND

The application of ribo nucleic acids for molecular studies requires high integrity and quality of extracted total RNA samples. In addition, the need to transfer RNA samples at room temperature without special treatments such as ice and liquid nitrogen storage according to international transport laws highlights the importance of low cost alternative methods such as RNA air-drying, lyophilisation and transportable agents. In this study, the quality and quantity of air-dried RNA samples from leaf, petiole and bark tissues of different olive genotypes using several RNA extraction methods were compared with lyophilized ground leaves and RNAlater-stored tissue samples before precipitation. The quality of RNA and prepared libraries were checked by several techniques including agarose and polyacrylamide gel electrophoresis, Agilent quality control, RT-PCR amplification of housekeeping and viral genes and high throughput sequencing.

RESULTS

Although RNA value varied amongst cultivars, RNA extraction with TRIzol™ Reagent in fresh extractions and samples stored in RNAlater before RNA extraction resulted in 455.26 ng/µL and 63.46 ng/µL (mean value of cultivars) as the highest RNA concentration averages, respectively. RNA samples extracted by TRIzol™ Reagents and stored for a short term at - 80 °C before air-drying showed the third highest concentration (44.87 ng/µL). The synthesized cDNAs quality for PCR amplification of housekeeping genes (Rbc 1 and Nad 5) and partial genomes of Arabis mosaic virus and Cucumber mosaic virus showed satisfactory results in RNA samples extracted by TRIzol™ Reagents despite its variation amongst cultivars.

CONCLUSIONS

Considering the difficulties in the extraction of high quality and quantity RNA in olive for molecular analyses, this study demonstrated that RNA extraction method based on TRIzol™ Reagent can be considered for virobiome studies of both fresh and air-dried samples.

Strategies to deliver RNA by nanoparticles for therapeutic potential

The use of a variety of RNA molecules, including messenger RNA, small interfering RNA, and microRNA, has shown great potential for prevention and therapy of many pathologies. However, this therapeutic promise has historically been limited by short in vivo half-life, lack of targeted delivery, and safety issues. Nanoparticle (NP)-mediated delivery has been a successful platform to overcome these limitations, with multiple formulations already in clinical trials and approved by the FDA. Although there is a diversity of NPs in terms of material formulation, size, shape, and charge that have been proposed for biomedical applications, specific modifications are required to facilitate sufficient RNA delivery and adequate therapeutic effect. This includes optimization of (i) RNA incorporation into NPs, (ii) specific cell targeting, (iii) cellular uptake and (iv) endosomal escape ability. In this review, we summarize the methods by which NPs can be modified for RNA delivery to achieve optimal therapeutic effects.

Pulmonary delivery of siRNA against acute lung injury/acute respiratory distress syndrome

The use of small interfering RNAs (siRNAs) has been under investigation for the treatment of several unmet medical needs, including acute lung injury/acute respiratory distress syndrome (ALI/ARDS) wherein siRNA may be implemented to modify the expression of pro-inflammatory cytokines and chemokines at the mRNA level. The properties such as clear anatomy, accessibility, and relatively low enzyme activity make the lung a good target for local siRNA therapy. However, the translation of siRNA is restricted by the inefficient delivery of siRNA therapeutics to the target cells due to the properties of naked siRNA. Thus, this review will focus on the various delivery systems that can be used and the different barriers that need to be surmounted for the development of stable inhalable siRNA formulations for human use before siRNA therapeutics for ALI/ARDS become available in the clinic.

Inhalable Microparticles Embedding Calcium Phosphate Nanoparticles for Heart Targeting: The Formulation Experimental Design

Inhalation of Calcium Phosphate nanoparticles (CaPs) has recently unmasked the potential of this nanomedicine for a respiratory lung-to-heart drug delivery targeting the myocardial cells. In this work, we investigated the development of a novel highly respirable dry powder embedding crystalline CaPs. Mannitol was selected as water soluble matrix excipient for constructing respirable dry microparticles by spray drying technique. A Quality by Design approach was applied for understanding the effect of the feed composition and spraying feed rate on typical quality attributes of inhalation powders. The in vitro aerodynamic behaviour of powders was evaluated using a medium resistance device. The inner structure and morphology of generated microparticles were also studied. The 1:4 ratio of CaPs/mannitol led to the generation of hollow microparticles, with the best aerodynamic performance. After microparticle dissolution, the released nanoparticles kept their original size.

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.

Engineering of Solid Dosage Forms of siRNA-Loaded Lipidoid-Polymer Hybrid Nanoparticles Using a Quality-by-Design Approach

Therapy based on RNA interference (RNAi), which can be mediated by exogenous small interfering RNA (siRNA), has potential for the management of diseases at the genetic level by silencing gene function(s). In all eukaryotic cells, RNAi is an endogenous regulatory mechanism, where messenger RNA (mRNA) is degraded, preventing its translation into protein. A significant advantage of RNAi therapy is that siRNA is very potent and gene silencing is highly specific, ensuring few off-target effects. However, the delivery of exogenous siRNA to the RNAi pathway in the cytosol is a challenge, and there is a need for development of advanced delivery systems to ensure safe and effective delivery of siRNA to the intracellular target site. Recently, we demonstrated the ability of lipid-polymer hybrid nanoparticles (LPNs) composed of cationic lipidoid 5 (L₅) and the biodegradable polymer poly(DL-lactic-co-glycolic acid) to effectively deliver siRNA directed against tumor necrosis factor alpha (TNF-α) intracellularly to macrophages. L₅ is a novel lipid-like material consisting of a tetraamine backbone linked to five C₁₂ alkyl chains. Here, we describe a systematic quality-by-design (QbD) approach including risk assessment and design of experiments to investigate the influence of critical formulation parameters (i.e., L₅ content and L₅:TNF-α siRNA ratio (w/w)) on the physicochemical properties and the TNF-α gene silencing ability of TNF-α siRNA-loaded LPNs, prepared by using a double emulsion solvent evaporation method. We then detail protocols for the manufacturing of more stable solid dosage forms of LPNs using freeze drying and spray drying processes, respectively. We also provide protocols for characterization of the physicochemical properties of the nanocomposite dry powders, including (1) process yield, (2) aerodynamic particle size, (3) surface morphology, (4) moisture content, and (5) solid state properties. General considerations are provided that emphasize the advantages and disadvantages of applying QbD approaches for optimizing nanoparticulate formulations.

Dry powder pharmaceutical biologics for inhalation therapy

Therapeutic biologics such as genes, peptides, proteins, virus and cells provide clinical benefits and are becoming increasingly important tools in respiratory medicine. Pulmonary delivery of therapeutic biologics enables the potential for safe and effective treatment option for respiratory diseases due to high bioavailability while minimizing absorption into the systemic circulation, reducing off-target toxicity to other organs. Development of inhalable powder formulation requires stabilization of complex biological materials, and each type of biologics may present unique challenges and require different formulation strategy combined with manufacture process to ensure biological and physical stabilities during production and over shelf-life. This review examines key formulation strategies for stabilizing proteins, nucleic acids, virus (bacteriophages) and bacterial cells in inhalable powders. It also covers characterization methods used to assess physicochemical properties and aerosol performance of the powders, biological activity and structural integrity of the biologics, and chemical analysis at the nanoscale. Furthermore, the review includes manufacture technologies which are based on lyophilization and spray-drying as they have been applied to manufacture Food and Drug Administration (FDA)-approved protein powders. In perspective, formulation and manufacture of inhalable powders for biologic are highly challenging but attainable. The key requirements are the stability of both the biologics and the powder, along with the powder dispersibility. The formulation to be developed depends on the manufacture process as it will subject the biologics to different stresses (temperature, mechanical and chemical) which could lead to degradation by different pathways. Stabilizing excipients coupled with the suitable choice of process can alleviate the stability issues of inhaled powders of biologics.

Formulation and clinical perspectives of inhalation-based nanocarrier delivery: a new archetype in lung cancer treatment

Despite tremendous research in targeted delivery and specific molecular inhibitors (gene delivery), cytotoxic drug delivery through inhalation has been seen as a core part in the treatment of the lung cancer. Inhalation delivery provides a high dose of the drug directly to the lungs without affecting other body organs, increasing the therapeutic ratio. This article reviews the research performed over the last several decades regarding inhalation delivery of various cancer therapeutics for the treatment of lung cancer. Nevertheless, pulmonary administration of nanocarrier-based cancer therapeutics for lung cancer therapy is still in its infancy and faces greater than expected challenges. This article focuses on the current inhalable nanocarrier-based drugs for lung cancer treatment.

Pulmonary siRNA delivery for lung disease: Review of recent progress and challenges

Lung diseases are a leading cause of mortality worldwide and there exists urgent need for new therapies. Approval of the first siRNA treatments in humans has opened the door for further exploration of this therapeutic strategy for other disease states. Pulmonary delivery of siRNA-based biopharmaceuticals offers the potential to address multiple unmet medical needs in lung-related diseases because of the specific physiology of the lung and characteristic properties of siRNA. Inhalation-based siRNA delivery designed for efficient, targeted delivery to specific cells within the lung holds great promise. Efficient delivery of siRNA directly to the lung, however, is relatively complex. This review focuses on the barriers that impact pulmonary siRNA delivery and successful recent approaches to advance this field forward. We focus on the pulmonary barriers that affect siRNA delivery, the disease-dependent pathological changes and their role in pulmonary disease and impact on siRNA delivery, as well as the recent development on the pulmonary siRNA delivery systems.

Polymer-Lipid Pharmaceutical Nanocarriers: Innovations by New Formulations and Production Technologies

Some issues in pharmaceutical therapies such as instability, poor membrane permeability, and bioavailability of drugs can be solved by the design of suitable delivery systems based on the combination of two pillar classes of ingredients: polymers and lipids. At the same time, modern technologies are required to overcome production limitations (low productivity, high energy consumption, expensive setup, long process times) to pass at the industrial level. In this paper, a summary of applications of polymeric and lipid materials combined as nanostructures (hybrid nanocarriers) is reported. Then, recent techniques adopted in the production of hybrid nanoparticles are discussed, highlighting limitations still present that hold back the industrial implementation.

Optimizing the Intracellular Delivery of Therapeutic Anti-inflammatory TNF-α siRNA to Activated Macrophages Using Lipidoid-Polymer Hybrid Nanoparticles

RNA interference (RNAi) has an unprecedented potential as a therapeutic strategy for reversibly silencing the expression of any gene. Therapeutic delivery of the RNAi mediator, i.e., small interfering RNA (siRNA), can be used to address diseases characterized by gene overexpression, for example inflammatory conditions like chronic obstructive pulmonary disease (COPD). Macrophages play a key role in COPD pathogenesis and are recruited to the airways and lung parenchyma, where they release proinflammatory cytokines, e.g., tumor necrosis factor-alpha (TNF-α). Hence, targeting TNF-α with siRNA is a promising therapeutic approach for COPD management. However, a safe and effective delivery system is required for delivery of TNF-α siRNA into the cytosol of hard-to-transfect macrophages. The purpose of this study was to optimize the intracellular delivery of TNF-α siRNA to the lipopolysaccharide-activated murine macrophage cell line RAW 264.7 using lipidoid-polymer hybrid nanoparticles (LPNs) composed of the lipid-like transfection agent lipidoid 5 (L₅) and the biodegradable polymer poly (D,L-lactide-co-glycolide). Applying a quality-by-design approach, the influence of critical formulation variables, i.e., the L₅ content and the L₅:siRNA ratio (w/w), on critical quality attributes (CQAs) was investigated systematically using risk assessment and design of experiments, followed by delineation of an optimal operating space (OOS). The CQAs were identified based on the quality target product profile and included size, polydispersity index, zeta potential, encapsulation efficiency and loading for achieving efficient and safe TNF-α gene silencing in activated RAW 264.7 cells. Formulations inducing efficient gene silencing and low cytotoxicity were identified, and the optimal formulations displayed L₅ contents of 15 and 20% (w/w), respectively, and an L₅:siRNA weight ratio of 15:1. All tested formulations within the OOS mediated efficient and sequence-specific TNF-α gene silencing in RAW 264.7 cells at TNF-α-siRNA concentrations, which were significantly lower than the concentrations required of non-encapsulated TNF-α-siRNA, highlighting the benefit of the delivery system. The results also demonstrate that increasing the loading of siRNA into the delivery system does not necessarily imply enhanced gene silencing. This opens new avenues for further exploitation of LPNs as a robust platform technology for delivering TNF-α siRNA to macrophages, e.g., in the management of COPD.

Long non-coding RNAs: From disease code to drug role

Enormous studies have corroborated that long non-coding RNAs (lncRNAs) extensively participate in crucial physiological processes such as metabolism and immunity, and are closely related to the occurrence and development of tumors, cardiovascular diseases, nervous system disorders, nephropathy, and other diseases. The application of lncRNAs as biomarkers or intervention targets can provide new insights into the diagnosis and treatment of diseases. This paper has focused on the emerging research into lncRNAs as pharmacological targets and has reviewed the transition of lncRNAs from the role of disease coding to acting as drug candidates, including the current status and progress in preclinical research. Cutting-edge strategies for lncRNA modulation have been summarized, including the sources of lncRNA-related drugs, such as genetic technology and small-molecule compounds, and related delivery methods. The current progress of clinical trials of lncRNA-targeting drugs is also discussed. This information will form a latest updated reference for research and development of lncRNA-based drugs.

Inhaled RNA Therapeutics for Obstructive Airway Diseases: Recent Advances and Future Prospects

Obstructive airway diseases, e.g., chronic obstructive pulmonary disease (COPD) and asthma, represent leading causes of morbidity and mortality worldwide. However, the efficacy of currently available inhaled therapeutics is not sufficient for arresting disease progression and decreasing mortality, hence providing an urgent need for development of novel therapeutics. Local delivery to the airways via inhalation is promising for novel drugs, because it allows for delivery directly to the target site of action and minimizes systemic drug exposure. In addition, novel drug modalities like RNA therapeutics provide entirely new opportunities for highly specific treatment of airway diseases. Here, we review state of the art of conventional inhaled drugs used for the treatment of COPD and asthma with focus on quality attributes of inhaled medicines, and we outline the therapeutic potential and safety of novel drugs. Subsequently, we present recent advances in manufacturing of thermostable solid dosage forms for pulmonary administration, important quality attributes of inhalable dry powder formulations, and obstacles for the translation of inhalable solid dosage forms to the clinic. Delivery challenges for inhaled RNA therapeutics and delivery technologies used to overcome them are also discussed. Finally, we present future prospects of novel inhaled RNA-based therapeutics for treatment of obstructive airways diseases, and highlight major knowledge gaps, which require further investigation to advance RNA-based medicine towards the bedside.

Nanoparticles-assisted delivery of antiviral-siRNA as inhalable treatment for human respiratory viruses: A candidate approach against SARS-COV-2

The current pandemic of coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) has challenged healthcare structures across the globe. Although a few therapies are approved by FDA, the search for better treatment options is continuously on rise. Clinical management includes infection prevention and supportive care such as supplemental oxygen and mechanical ventilatory support. Given the urgent nature of the pandemic and the number of companies and researchers developing COVID-19 related therapies, FDA has created an emergency program to move potential treatments with already approved drugs to patients as quickly as possible in parallel to the development of new drugs that must first pass the clinical trials. In this manuscript, we have reviewed the available literature on the use of sequence-specific degradation of viral genome using short-interfering RNA (siRNA) suggesting it as a possible treatment against SARS-CoV-2. Delivery of siRNA can be promoted by the use of FDA approved lipids, polymers or lipid-polymer hybrids. These nanoparticulate systems can be engineered to exhibit increased targetability and formulated as inhalable aerosols.

Novel drug delivery systems targeting oxidative stress in chronic obstructive pulmonary disease: a review

Oxidative stress is significantly involved in the pathogenesis and progression of chronic obstructive pulmonary disease (COPD). Combining antioxidant drugs or nutrients results in a noteworthy therapeutic value in animal models of COPD. However, the benefits have not been reproduced in clinical applications, this may be attributed to the limited absorption, concentration, and half-life of exogenous antioxidants. Therefore, novel drug delivery systems to combat oxidative stress in COPD are needed. This review presents a brief insight into the current knowledge on the role of oxidative stress and highlights the recent trends in novel drug delivery carriers that could aid in combating oxidative stress in COPD. The introduction of nanotechnology has enabled researchers to overcome several problems and improve the pharmacokinetics and bioavailability of drugs. Large porous microparticles, and porous nanoparticle-encapsulated microparticles are the most promising carriers for achieving effective pulmonary deposition of inhaled medication and obtaining controlled drug release. However, translating drug delivery systems for administration in pulmonary clinical settings is still in its initial phases.

Bcl-2-associated athanogene 5 overexpression attenuates catecholamine-induced vascular endothelial cell apoptosis

Bcl-2 associated athanogene 5 (Bag5) is a novel endoplasmic reticulum (ER) regulator. However, its role in catecholamine-induced endothelial cells damage has not been fully understood. In our study, catecholamine was used to mimic hypertension-related endothelial cell damage. Then, western blots, enzyme-linked immunosorbent assay, immunofluorescence, quantitative polymerase chain reaction and pathway analysis were conducted to analyze the role of Bag5 in endothelial cell damage in response to catecholamine. Our results indicated that the endothelial cell viability was impaired by catecholamine. Interestingly, Bag5 overexpression significantly reversed endothelial cell viability. Mechanistically, Bag5 overexpression inhibited ER stress, attenuated oxidative stress and repressed inflammation in catecholamine-treated endothelial cells. These beneficial effects finally contributed to endothelial cell survival under catecholamine treatment. Pathway analysis demonstrated that Bag5 was under the control of the mitogen-activated protein kinase (MAPK)-extracellular-signal-regulated kinase (ERK) signaling pathway. Reactivation of the MAPK-ERK pathway could upregulate Bag5 expression and thus promote endothelial cell survival through inhibiting oxidative stress, ER stress, and inflammation. Altogether, our results illustrate that Bag5 overexpression sustains endothelial cell survival in response to catecholamine treatment. This finding identifies Bag5 downregulation and the inactivated MAPK-ERK pathway as potential mechanisms underlying catecholamine-induced endothelial cell damage.

Oxidative stress-induced cardiomyocyte apoptosis is associated with dysregulated Akt/p53 signaling pathway

Oxidative stress may play a crucial role in cardiac and vascular abnormalities in different types of cardiovascular diseases. In the present study, we explored the mechanism underlying oxidative stress-mediated cardiomyocyte apoptosis with a focus on the Akt-p53 signaling pathway. In vitro, cardiomyocyte was cultured with different concentrations of hydrogen peroxide. Then, cardiomyocyte viability, apoptosis rate and signaling pathway were analyzed through ELISA, immunofluorescence, qPCR and western blots. The results indicated that oxidative stress caused cardiomyocyte apoptosis in a dose-dependent manner. Mechanistically, oxidative stress inhibited cardiomyocyte glucose metabolism and promoted lactic acid accumulation. Besides, oxidative stress triggered calcium overload in cardiomyocyte. Finally, we found that oxidative stress inhibited the activity of Akt pathway while activated p53 signaling pathway. Genetic knockdown of p53 abolished oxidative stress-mediated cardiomyocyte injury and death through regulating the expressions and activities of caspase-3 and Bax. Altogether, our results illustrate that oxidative stress is associated with cardiomyocyte apoptosis through a mechanism involving dysregulated Akt/p53 signaling pathway.

Macrophage stimulating 1-induced inflammation response promotes aortic aneurysm formation through triggering endothelial cells death and activating the NF-κB signaling pathway

Aortic aneurysm formation is associated with endothelial cells dysfunction through an undefined mechanism. Macrophage stimulating 1 (Mst1) and NF-κB signaling pathway have been found to be related to inflammation response in endothelial cell damage. The goal of our study is to explore the role of Mst1 in regulating endothelial cell viability with a focus on NF-κB signaling pathway and inflammation response. Endothelial cell viability and death were determined via immunofluorescence and ELISA. Agonist of NF-κB signaling pathway and siRNA against Mst1 were used. The results in our study demonstrated that Mst1 transcription and expression were significantly elevated after exposure to oxidative stress in endothelial cells. Once loss of Mst1 through transfection of siRNA (si-Mst1), endothelial cell viability and survival rate were rapidly increased in response to oxidative stress. In addition, we also found that Mst1 controlled inflammation response and mitochondrial function in endothelial cells. Re-activation of NF-κB signaling pathway was followed by an activation of inflammation response and mitochondrial dysfunction, as evidenced by increased expression of inflammation factors and decreased ATP synthesis. Altogether, our results identify Mst1 as the primary factors responsible for endothelial cells dysfunction in aneurysms formation through inducing inflammation response, endothelial apoptosis, and NF-κB signaling pathway activation.