Advances in Pulmonary Delivery of Nanoparticles

Nanostructure-Mediated Transport of Therapeutics through Epithelial Barriers

The ability to precisely treat human disease is facilitated by the sophisticated design of pharmacologic agents. Nanotechnology has emerged as a valuable approach to creating vehicles that can specifically target organ systems, effectively traverse epithelial barriers, and protect agents from premature degradation. In this review, we discuss the molecular basis for epithelial barrier function, focusing on tight junctions, and describe different pathways that drugs can use to cross barrier-forming tissue, including the paracellular route and transcytosis. Unique features of drug delivery applied to different organ systems are addressed: transdermal, ocular, pulmonary, and oral delivery. We also discuss how design elements of different nanoscale systems, such as composition and nanostructured architecture, can be used to specifically enhance transepithelial delivery. The ability to tailor nanoscale drug delivery vehicles to leverage epithelial barrier biology is an emerging theme in the pursuit of facilitating the efficacious delivery of pharmacologic agents.

Emerging application of nanomedicine-based therapy in acute respiratory distress syndrome

Acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) are serious lung injuries caused by various factors, leading to increased permeability of the alveolar-capillary barrier, reduced stability of the alveoli, inflammatory response, and hypoxemia. Despite several decades of research since ARDS was first formally described in 1967, reliable clinical treatment options are still lacking. Currently, supportive therapy and mechanical ventilation are prioritized, and there is no medication that can be completely effective in clinical treatment. In recent years, nanomedicine has developed rapidly and has exciting preclinical treatment capabilities. Using a drug delivery system based on nanobiotechnology, local drugs can be continuously released in lung tissue at therapeutic levels, reducing the frequency of administration and improving patient compliance. Furthermore, this novel drug delivery system can target specific sites and reduce systemic side effects. Currently, many nanomedicine treatment options for ARDS have demonstrated efficacy. This review briefly introduces the pathophysiology of ARDS, discusses various research progress on using nanomedicine to treat ARDS, and anticipates future developments in related fields.

Overcoming the Low-Stability Bottleneck in the Clinical Translation of Liposomal Pressurized Metered-Dose Inhalers: A Shell Stabilization Strategy Inspired by Biomineralization

Currently, several types of inhalable liposomes have been developed. Among them, liposomal pressurized metered-dose inhalers (pMDIs) have gained much attention due to their cost-effectiveness, patient compliance, and accurate dosages. However, the clinical application of liposomal pMDIs has been hindered by the low stability, i.e., the tendency of the aggregation of the liposome lipid bilayer in hydrophobic propellant medium and brittleness under high mechanical forces. Biomineralization is an evolutionary mechanism that organisms use to resist harsh external environments in nature, providing mechanical support and protection effects. Inspired by such a concept, this paper proposes a shell stabilization strategy (SSS) to solve the problem of the low stability of liposomal pMDIs. Depending on the shell material used, the SSS can be classified into biomineralization (biomineralized using calcium, silicon, manganese, titanium, gadolinium, etc.) biomineralization-like (composite with protein), and layer-by-layer (LbL) assembly (multiple shells structured with diverse materials). This work evaluated the potential of this strategy by reviewing studies on the formation of shells deposited on liposomes or similar structures. It also covered useful synthesis strategies and active molecules/functional groups for modification. We aimed to put forward new insights to promote the stability of liposomal pMDIs and shed some light on the clinical translation of relevant products.

Supercritical antisolvent-fluidized bed for the preparation of dry powder inhaler for pulmonary delivery of nanomedicine

The supercritical antisolvent-fluidized bed coating process (SAS-FB) shows great potential as a technique to manufacture dry powder inhaler (DPI) that incorporate nanodrugs onto micronized matrix particles, capitalizing on the merits of both nanoparticle and pulmonary delivery. In this study, naringin (NAR), a pharmacologically active flavonoid with low solubility and in vivo degradation issues, was utilized as a model active pharmaceutical ingredient to construct nanomedicine-based DPI through SAS-FB. It is showed that processed NAR exhibited a near-spherical shape and an amorphous structure with an average size of around 130 nm. Notably, SAS-FB products prepared with different fluidized matrices resulted in varying deposition patterns, particularly when mixed with a coarse lactose to enhance the fine particle fraction (FPF) of the formulations. The FPF was positively associated with specific surface area of the SAS-FB products, while the specific surface area was directly related to surface roughness and particle size. In vitro dissolution studies using simulated lung fluid revealed that the NAR nanoparticles coated on the products were released immediately upon contact with solution, with a cumulative dissolution exceeding 90% within the first minute. Importantly, compared to oral raw NAR, the optimized DPI formulation demonstrated superior in vivo plasmatic and pulmonary AUC0→∞ by 51.33-fold and 104.07-fold respectively in a Sprague-Dawley rat model. Overall, SAS- FB technology provides a practical approach to produce nanomedicine DPI product that combine the benefits of nanoparticles with the aerodynamics properties of inhaled microparticles.

Characteristics and release of isoniazid from inhalable alginate/carrageenan microspheres

Aim: Inhalable microspheres made of polymers as a targeted drug delivery system have been developed to overcome the limitation of current treatments in Tuberculosis. Materials & methods: Isoniazid inhalable microspheres were created using a gelation ionotropic method with sodium alginate, carrageenan and calcium chloride in four different formulations. Result: The particle morphology has smooth surfaces and round spherical shapes with sizes below 5 μm; good flowability. The drug loading and entrapment efficiency values ranged from 1.69 to 2.75% and 62.44 to 85.30%, respectively. The microspheres drug release followed the Korsmeyer-Peppas model, indicating Fickian diffusion. Conclusion: Isoniazid inhalable microspheres achieved as targeted lung delivery for tuberculosis treatment.

Development and characterization of lung surfactant-coated polymer nanoparticles for pulmonary drug delivery

Lung cancer is often diagnosed at an advanced stage where tumors are usually inoperable and first-line therapies are inefficient and have off-targeted adverse effects, resulting in poor patient survival. Here, we report the development of an inhalable poly lactic-co-glycolic acid polymer-based nanoparticle (PLGA-NP) formulation with a biomimetic Infasurf® lung surfactant (LS) coating, for localized and sustained lung cancer drug delivery. The nanoparticles (188 ± 7 nm) were stable in phosphate buffered saline, serum and Gamble's solution (simulated lung fluid), and demonstrated cytocompatibility up to 1000 μg/mL concentration and dose-dependent uptake by lung cancer cells. The LS coating significantly decreased nanoparticle (NP) uptake by NR8383 alveolar macrophages in vitro compared to uncoated NPs. The coating, however, did not impair NP uptake by A549 lung adenocarcinoma cells. The anti-cancer drug gemcitabine hydrochloride encapsulated in the PLGA core was released in a sustained manner while the paclitaxel loaded in the LS shell demonstrated a rapid or burst release profile over 21 days. The drug-loaded NPs significantly decreased cancer cell survival and colony formation in vitro compared to free drugs and single drug-loaded NPs. In vivo studies confirmed greater retention of LS-coated NPs in the lungs of C57BL/6 WT mice compared to uncoated NPs, at 24 h and 72 h following intranasal administration. The overall results confirm that LS coating is a unique strategy for cloaking polymeric NPs to potentially prevent their rapid lung clearance and facilitate prolonged pulmonary drug delivery.

Pharmacologic therapies of ARDS: From natural herb to nanomedicine

Acute respiratory distress syndrome (ARDS) is a common critical illness in respiratory care units with a huge public health burden. Despite tremendous advances in the prevention and treatment of ARDS, it remains the main cause of intensive care unit (ICU) management, and the mortality rate of ARDS remains unacceptably high. The poor performance of ARDS is closely related to its heterogeneous clinical syndrome caused by complicated pathophysiology. Based on the different pathophysiology phases, drugs, protective mechanical ventilation, conservative fluid therapy, and other treatment have been developed to serve as the ARDS therapeutic methods. In recent years, there has been a rapid development in nanomedicine, in which nanoparticles as drug delivery vehicles have been extensively studied in the treatment of ARDS. This study provides an overview of pharmacologic therapies for ARDS, including conventional drugs, natural medicine therapy, and nanomedicine. Particularly, we discuss the unique mechanism and strength of nanomedicine which may provide great promises in treating ARDS in the future.

Advances and opportunities in nanoimaging agents for the diagnosis of inflammatory lung diseases

The development of rapid, noninvasive diagnostics to detect lung diseases is a great need after the COVID-2019 outbreak. The nanotechnology-based approach has improved imaging and facilitates the early diagnosis of inflammatory lung diseases. The multifunctional properties of nanoprobes enable better spatial-temporal resolution and a high signal-to-noise ratio in imaging. Targeted nanoimaging agents have been used to bind specific tissues in inflammatory lungs for early-stage diagnosis. However, nanobased imaging approaches for inflammatory lung diseases are still in their infancy. This review provides a solution-focused approach to exploring medical imaging technologies and nanoprobes for the detection of inflammatory lung diseases. Prospects for the development of contrast agents for lung disease detection are also discussed.

Nanotechnology-Assisted Metered-Dose Inhalers (MDIs) for High-Performance Pulmonary Drug Delivery Applications

PURPOSE

Respiratory disorders pose a major threat to the morbidity and mortality to public health. Here we reviewed the nanotechnology based pulmonary drug delivery using metered dose inhalers.

METHODS

Major respiratory diseases such as chronic obstructive pulmonary diseases (COPD), asthma, acute lower respiratory tract infections, tuberculosis (TB) and lung cancer. At present, common treatments for respiratory disorders include surgery, radiation, immunotherapy, and chemotherapy or a combination. The major challenge is development of systemic delivery of the chemotherapeutic agents to the respiratory system. Conventional delivery of chemotherapy has various limitation and adverse side effected. Hence, targeted, and systemic delivery need to be developed. Towards this direction nanotechnology, based controlled, targeted, and systemic drug delivery systems are potential candidate to enhance therapeutic efficacy with minimum side effect. Among different route of administration, pulmonary delivery has unique benefits such as circumvents first pass hepatic metabolism and reduces dose and side effects.

RESULTS

Respiratory disorders pose a major threat to the morbidity and mortality to public health globally. Pulmonary delivery can be achieved through various drug delivery devices such as nebulizers, dry powder inhalers, and metered dose inhalers. Among them, metered dose inhalers are the most interesting and first choice of clinician over others. This review focused on nanotechnology based pulmonary drug delivery using metered dose inhalers. This report focused on delivery of various types of therapeutics using nanocarriers such as polymeric nanoparticles and micelles, dendrimers, lipid nanocarriers such as liposomes, solid lipid nanostructures and nanostructured lipid carriers, and other using metered dose inhalers discussed comprehensively. This report provides insight about the effect of parameters of MDI such as co-solvent, propellants, actuators shape, nozzle diameters, and jet lengths, and respiratory flow rate, and particle size of co-suspension of drug on aerodynamics and lung deposition of formulation. This review also provided the insight about various metered dose inhalers market scenario and digital metered dose inhalers.

CONCLUSION

This report concluded the clinical potential of metered dose inhalers, summary of current progress and future perspectives towards the smart digital metered dose inhalers development.

Biocomposite-based nanostructured delivery systems for treatment and control of inflammatory lung diseases

Diseases related to the lungs are among the most prevalent medical problems threatening human life. The treatment options and therapeutics available for these diseases are hindered by inadequate drug concentrations at pathological sites, a dearth of cell-specific targeting and different biological barriers in the alveoli or conducting airways. Nanostructured delivery systems for lung drug delivery have been significant in addressing these issues. The strategies used include surface engineering by altering the material structure or incorporation of specific ligands to reach prespecified targets. The unique characteristics of nanoparticles, such as controlled size and distribution, surface functional groups and therapeutic release triggering capabilities, are tailored to specific requirements to overcome the major therapeutic barriers in pulmonary diseases. In the present review, the authors intend to deliver significant up-to-date research in nanostructured therapies in inflammatory lung diseases with an emphasis on biocomposite-based nanoparticles.

Targeted drug therapy in nonsmall cell lung cancer: clinical significance and possible solutions-part II (role of nanocarriers)

INTRODUCTION

Nonsmall cell lung cancer (NSCLC) accounts for 80-85% of the cases of lung cancer. The conventional therapeutic effective dosage forms used to treat NSCLC are associated with rigid administration schedules, adverse effects, and may be associated with acquired resistance to therapy. Nanocarriers may provide a suitable alternative to regular formulations to overcome inherent drawbacks and provide better treatment modalities for the patient.

AREAS COVERED

The article explores the application of drug loaded nanocarriers for lung cancer treatment. Drug-loaded nanocarriers can be modified to achieve controlled delivery at the desired tumor infested site. The type of nanocarriers employed are diverse based on polymers, liposomes, metals and a combination of two or more different base materials (hybrids). These may be designed for systemic delivery or local delivery to the lung compartment (via inhalation).

EXPERT OPINION

Nanocarriers can improve pharmacokinetics of the drug payload by improving its delivery to the desired location and can reduce associated systemic toxicities. Through nanocarriers, a wide variety of therapeutics can be administered and targeted to the cancerous site. Some examples of the utilities of nanocarriers are codelivery of drugs, gene delivery, and delivery of other biologics. Overall, the nanocarriers have promising potential in improving therapeutic efficacy of drugs used in NSCLC.

Current Status of Alginate in Drug Delivery

Alginate is one of the natural polymers that are often used in drug- and protein-delivery systems. The use of alginate can provide several advantages including ease of preparation, biocompatibility, biodegradability, and nontoxicity. It can be applied to various routes of drug administration including targeted or localized drug-delivery systems. The development of alginates as a selected polymer in various delivery systems can be adjusted depending on the challenges that must be overcome by drug or proteins or the system itself. The increased effectiveness and safety of sodium alginate in the drug- or protein-delivery system are evidenced by changing the physicochemical characteristics of the drug or proteins. In this review, various routes of alginate-based drug or protein delivery, the effectivity of alginate in the stem cells, and cell encapsulation have been discussed. The recent advances in the in vivo alginate-based drug-delivery systems as well as their toxicities have also been reviewed.

mPEG-icariin nanoparticles for treating myocardial ischaemia

Icariin (ICA), a major active ingredient from Chinese medicine, has unique pharmacological effects on ischaemic heart disease. However, its hydrophobic property limits its administration and leads to poor efficacy. This work aimed to change its hydrophobic property and improve the treatment efficacy. We designed a new nano-drug to increase the ICA delivery. ICA was modified with hydrophilic polyethylene glycol monomethyl ether (mPEG) by a succinic anhydride linker to form a polyethylene glycol-icariin (mPEG-ICA) polymer. The structure of this polymer was identified by Fourier transform infrared spectroscopy and nuclear magnetic resonance spectroscopy. The content of ICA in the polymer was 32% as detected by ultraviolet spectrophotometry. mPEG-ICA nanoparticles, of 143.3 nm, were prepared by the dialysis method, and zeta potential was 0.439 mV by dynamic light scattering. The nanoparticles had a spherical shape on transmission electron microscopy. In media with pH 7.4 and 6.8, ICA release from mPEG-ICA nanoparticles after 72 h was about 0.78% and 64.05%, respectively, so the ICA release depended on the release media pH. On MTT and lactate dehydrogenase activity assay, mPEG-ICA nanoparticles could reduce cell damage induced by oxgen-glucose deprivation. Hoechst 33258 staining and TUNEL and AnnexinV-FITC/PI double staining showed that ICA nanoparticles could increase the activity of H9c2 cardiomyocytes under oxgen-glucose deprivation conditions by decreasing apoptosis. ICA modified by hydrophilic mPEG could improve its efficacy.

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.

Inhaled nano- and microparticles for drug delivery

The 21st century has seen a paradigm shift to inhaled therapy, for both systemic and local drug delivery, due to the lung's favourable properties of a large surface area and high permeability. Pulmonary drug delivery possesses many advantages, including non-invasive route of administration, low metabolic activity, control environment for systemic absorption and avoids first bypass metabolism. However, because the lung is one of the major ports of entry, it has multiple clearance mechanisms, which prevent foreign particles from entering the body. Although these clearance mechanisms maintain the sterility of the lung, clearance mechanisms can also act as barriers to the therapeutic effectiveness of inhaled drugs. This effectiveness is also influenced by the deposition site and delivered dose. Particulate-based drug delivery systems have emerged as an innovative and promising alternative to conventional inhaled drugs to circumvent pulmonary clearance mechanisms and provide enhanced therapeutic efficiency and controlled drug release. The principle of multiple pulmonary clearance mechanisms is reviewed, including mucociliary, alveolar macrophages, absorptive, and metabolic degradation. This review also discusses the current approaches and formulations developed to achieve optimal pulmonary drug delivery systems.