Preparation and characterization of biodegradable paclitaxel loaded alginate microparticles for pulmonary delivery

Building respirable powder architectures: utilizing polysaccharides for precise control of particle morphology for enhanced pulmonary drug delivery

INTRODUCTION

Dry powder inhaler (DPI) formulations are gaining attention as universal formulations with applications in a diverse range of drug formulations. The practical application of DPIs to pulmonary drugs requires enhancing their delivery efficiency to the target sites for various treatment modalities. Previous reviews have not explored the relation between particle morphology and delivery to different pulmonary regions. This review introduces new approaches to improve targeted DPI delivery using novel particle design such as supraparticles and metal-organic frameworks based on cyclodextrin.

AREAS COVERED

This review focuses on the design of DPI formulations using polysaccharides, promising excipients not yet approved by regulatory agencies. These excipients can be used to design various particle morphologies by controlling their physicochemical properties and manufacturing methods.

EXPERT OPINION

Challenges associated with DPI formulations include poor access to the lungs and low delivery efficiency to target sites in the lung. The restricted applicability of typical excipients contributes to their limited use. However, new formulations based on polysaccharides are expected to establish a technological foundation for the development of DPIs capable of delivering modalities specific to different lung target sites, thereby enhancing drug delivery.

Formulation of Folate Receptor-Targeted Silibinin-Loaded Inhalable Chitosan Nanoparticles by the QbD Approach for Lung Cancer Targeted Delivery

Aim: Targeted delivery of chemotherapeutics by functionalized nanoparticles exhibits a wonderful prospect for cancer treatment. The main objective of this research was to develop folate receptor-targeted silibinin (SB)-loaded inhalable polymeric nanoparticles (FA-CS-SB-NPs) for the treatment of lung cancer. Method: The qbD approach was implemented to prepare SB-loaded nanoparticles. Folic acid was conjugated by electrostatic conjugation in an optimized batch. The therapeutic potentials of formulations were determined using a lung cancer cell-bearing rat model. Result: Optimized formulation exhibited a spherical surface with a mean particle size of 275 ± 1.20 nm, a PDI of 0.234 ± 0.07, a ζ-potential of 32.50 ± 0.21, an entrapment efficiency of 75.52 ± 0.87%, and a CDR of 63.25 ± 1.21% at 48 h. Aerodynamic behaviors such as the mass median aerodynamic diameter (MMAD) and geometric size distribution (GSD) were found to be 2.75 ± 1.02 and 3.15 ± 0.88 μm, respectively. After 24 h of incubation with FA-CS-SB-NPs, the IC50 value was found to be 24.5 g/mL. FA-SB-CS-NPs maintained a significantly higher deposition of SB in lung tissues. Conclusions: Thus, the noninvasive nature and target specificity of FA-CS-SB-NPs pave the way for pulmonary delivery for treating lung cancer.

Nanocarrier-Mediated Drug Delivery via Inhalational Route for Lung Cancer Therapy: A Systematic and Updated Review

Lung cancer is one of the most severe lethal malignancies, with approximately 1.6 million deaths every year. Lung cancer can be broadly categorised into small and non-small-cell lung cancer. The traditional chemotherapy is nonspecific, destroys healthy cells and produces systemic toxicity; targeted inhalation drug delivery in conjunction with nanoformulations has piqued interest as an approach for improving chemotherapeutic drug activity in the treatment of lung cancer. Our aim is to discuss the impact of polymer and lipid-based nanocarriers (polymeric nanoparticles, liposomes, niosomes, nanostructured lipid carriers, etc.) to treat lung cancer via the inhalational route of drug administration. This review also highlights the clinical studies, patent reports and latest investigations related to lung cancer treatment through the pulmonary route. In accordance with the PRISMA guideline, a systematic literature search was carried out for published works between 2005 and 2023. The keywords used were lung cancer, pulmonary delivery, inhalational drug delivery, liposomes in lung cancer, nanotechnology in lung cancer, etc. Several articles were searched, screened, reviewed and included. The analysis demonstrated the potential of polymer and lipid-based nanocarriers to improve the entrapment of drugs, sustained release, enhanced permeability, targeted drug delivery and retention impact in lung tissues. Patents and clinical observations further strengthen the translational potential of these carrier systems for human use in lung cancer. This systematic review demonstrated the potential of pulmonary (inhalational) drug delivery approaches based on nanocarriers for lung cancer therapy.

Nebulized pH-Responsive Nanospray Combined with Pentoxifylline and Edaravone to Lungs for Efficient Treatments of Acute Respiratory Distress Syndrome

The COVID-19 pandemic has become an unprecedented global medical emergency, resulting in more than 5 million deaths. Acute respiratory distress syndrome (ARDS) caused by COVID-19, characterized by the release of a large number of pro-inflammatory cytokines and the production of excessive toxic ROS, is the most common serious complication leading to death. To develop new strategies for treating ARDS caused by COVID-19, a mouse model of ARDS was established by using lipopolysaccharide (LPS). Subsequently, we have constructed a novel nanospray with anti-inflammatory and antioxidant capacity by loading pentoxifylline (PTX) and edaravone (Eda) on zeolite imidazolate frameworks-8 (ZIF-8). This nanospray was endowed with synergetic therapy, which could kill two birds with one stone: (1) the loaded PTX played a powerful anti-inflammatory role by inhibiting the activation of inflammatory cells and the synthesis of pro-inflammatory cytokines; (2) Eda served as a free radical scavenger in ARDS. Furthermore, compared with the traditional intravenous administration, nanosprays can be administered directly and inhaled efficiently and reduce the risk of systemic adverse reactions greatly. This nanospray could not only coload two drugs efficiently but also realize acid-responsive release on local lung tissue. Importantly, ZIF8-EP nanospray showed an excellent therapeutic effect on ARDS in vitro and in vivo, which provided a new direction for the treatment of ARDS.

Characterization, in vitro digestibility and release properties of starch-linoleic acid-sodium alginate composite film

This study aimed to improve the complexing degree, digestibility and controlled release properties of the potato starch (PS)-linoleic acid (LA) complexes by encapsulating PS-LA complexes to sodium alginate (AG) beads. The results revealed that AG had a positive effect on the complexing index, R1047/1022 values, relative crystallinity, enthalpy and morphological structure of PS-LA-AG films, especially for PS-LA-AG film with the PS-LA: AG of 5:1. The in vitro digestion and hydrolysis kinetic analysis indicated that AG addition reduced the digestibility of PS-LA-AG films to a higher slowly digestible starch content and resistant starch content and a lower equilibrium hydrolysis percentage and kinetic constant. Furthermore, in vivo release study of PS-LA-AG films indicated a restrained release in simulated gastrointestinal conditions. Consequently, the results indicated that AG addition significantly improved the inclusion efficiency for the complex formation between PS and LA, which was beneficial for the design of resistant films to entrap and control release of unsaturated fatty.

Inhalation Dosage Forms: A Focus on Dry Powder Inhalers and Their Advancements

In this review, an extensive analysis of dry powder inhalers (DPIs) is offered, focusing on their characteristics, formulation, stability, and manufacturing. The advantages of pulmonary delivery were investigated, as well as the significance of the particle size in drug deposition. The preparation of DPI formulations was also comprehensively explored, including physico-chemical characterization of powders, powder processing techniques, and formulation considerations. In addition to manufacturing procedures, testing methods were also discussed, providing insights into the development and evaluation of DPI formulations. This review also explores the design basics and critical attributes specific to DPIs, highlighting the significance of their optimization to achieve an effective inhalation therapy. Additionally, the morphology and stability of 3 DPI capsules (Spiriva, Braltus, and Onbrez) were investigated, offering valuable insights into the properties of these formulations. Altogether, these findings contribute to a deeper understanding of DPIs and their development, performance, and optimization of inhalation dosage forms.

Pulmonary drug delivery: an effective and convenient delivery route to combat COVID-19

The recent outbreak of coronavirus disease 2019 (COVID-19) in Wuhan, China has spread rapidly around the world, leading to a widespread and urgent effort to develop and use comprehensive approaches in the treatment of COVID-19. While oral therapy is accepted as an effective and simple method, since the primary site of infection and disease progression of COVID-19 is mainly through the lungs, inhaled drug delivery directly to the lungs may be the most appropriate route of administration. To prevent or treat primary SARS-CoV-2 infections, it is essential to target the virus port of entry in the respiratory tract and airway epithelium, which requires rapid and high-intensity inhibition or control of viral entry or replication. To achieve success in this field, inhalation therapy is the most attractive treatment approach due to efficacy/safety profiles. In this review article, pulmonary drug delivery as a unique treatment option in lung diseases will be briefly reviewed. Then, possible inhalation therapies for the treatment of symptoms of COVID-19 will be discussed and the results of clinical trials will be presented. By pulmonary delivery of the currently approved drugs for COVID-19, efficacy of the treatment would be improved along with reducing systemic side effects.

Antioxidant Defense in Primary Murine Lung Cells following Short- and Long-Term Exposure to Plastic Particles

Polystyrene nano- and micro-sized plastic particles (NMP) are one of the common plastic materials produced that dramatically pollute the environment, water, and oceanic habitats worldwide. NMP are continuously absorbed by the body through a number of routes, especially via intestinal ingestion, dermal uptake, and inhalation into the lung. Several studies provided evidence of NMP provoking oxidative stress and affecting cellular responses. Yet, the NMP effects on primary lung cells have not been studied. To this end, we isolated and cultured murine lung cells and exposed them short-term or long-term to polystyrene 0.2-6.0 µm-sized NMP. We studied cellular consequences regarding oxidative stress, morphology, and secretion profiling. Visualization, distribution, and expression analyses confirmed lung cells accumulating NMP and showed several significant correlations with particle size. Moreover, we found substantial evidence of biological consequences of small-scale NMP uptake in lung cells. Besides alterations of cytokine secretion profiles resulting in inflammatory responses, indicators of oxidative stress were identified that were accompanied by Nrf2 and β-catenin signaling changes. Our results serve as an important basis to point out the potential hazards of plastic contaminations and uptake in lung cells.

Hydrogel systems for targeted cancer therapy

When hydrogel materials with excellent biocompatibility and biodegradability are used as excellent new drug carriers in the treatment of cancer, they confer the following three advantages. First, hydrogel materials can be used as a precise and controlled drug release systems, which can continuously and sequentially release chemotherapeutic drugs, radionuclides, immunosuppressants, hyperthermia agents, phototherapy agents and other substances and are widely used in the treatment of cancer through radiotherapy, chemotherapy, immunotherapy, hyperthermia, photodynamic therapy and photothermal therapy. Second, hydrogel materials have multiple sizes and multiple delivery routes, which can be targeted to different locations and types of cancer. This greatly improves the targeting of drugs, thereby reducing the dose of drugs and improving treatment effectiveness. Finally, hydrogel can intelligently respond to environmental changes according to internal and external environmental stimuli so that anti-cancer active substances can be remotely controlled and released on demand. Combining the abovementioned advantages, hydrogel materials have transformed into a hit in the field of cancer treatment, bringing hope to further increase the survival rate and quality of life of patients with cancer.

Inhalable Formulations to Treat Non-Small Cell Lung Cancer (NSCLC): Recent Therapies and Developments

Cancer has been the leading cause of mortalities, with lung cancer contributing 18% to overall deaths. Non-small cell lung cancer (NSCLC) accounts for about 85% of all lung cancers. The primary form of therapy used to treat lung cancer still includes oral and systemic administration of drugs, radiotherapy, or chemotherapy. Some patients have to go through a regime of combination therapy. Despite being the only available form of therapy, their use is limited due to the adverse effects, toxicity, and development of resistance over prolonged use. This led to a shift and progressive evolution into using pulmonary drug delivery systems. Being a non-invasive method of drug-administration and allowing localized delivery of drugs to cancer cells, inhalable drug delivery systems can lead to lower dosing and fewer systemic toxicities over other conventional routes. In this way, we can increase the actual local concentration of the drug in lungs, which will ultimately lead to better antitumor therapy. Nano-based systems also provide additional diagnostic advantages during lung cancer treatment, including imaging, screening, and tracking. Regardless of the advantages, pulmonary delivery is still in the early stages of development and various factors such as pharmacology, immunology, and toxicology should be taken into consideration for the development of suitable inhalable nano-based chemotherapeutic drugs. They face numerous physiological barriers such as lung retention and efficacy, and could also lead to toxicity due to prolonged exposure. Nano-carriers with a sustained drug release mechanism could help in overcoming these challenges. This review article will focus on the various inhalable formulations for targeted drug delivery, including nano-based delivery systems such as lipids, liposome, polymeric and inorganic nanocarriers, micelles, microparticles and nanoaggregates for lung cancer treatment. Various devices used in pulmonary drug delivery loaded on various nano-carriers are also discussed in detail.

Spray-Dried Inhalable Powder Formulations of Gentamicin Designed for Pneumonic Plague Therapy in a Mouse Model

Infection with Yersinia pestis (Y. pestis) may cause pneumonic plague, which is inevitably fatal without treatment. Gentamicin (GM), an aminoglycoside antibiotic, is a drug commonly used in the treatment of plague. However, it requires repeated intramuscular or intravenous administration. Pulmonary drug delivery is noninvasive, with the advantages of local targeting and reduced risk of systemic toxicity. In this study, GM powders were prepared using spray-drying technology. The powders displayed good physical and chemical properties and met the requirements for human pulmonary inhalation. The formulation of the powders was optimized using a 3² full factorial design. A formulation of 15% (w/w) of L-leucine was prepared, and the spray-drying process parameters using an inlet temperature of 120°C and a 15% pump rate were determined to produce the best powder. In addition, the optimized GM spray-dried powders were characterized in terms of morphology, crystallinity, powder fluidity, and aerodynamic particle size distribution analysis. In a mouse model of pneumonic plague, we compared the therapeutic effects among three administration routes, including subcutaneous injection, liquid atomization, and dry powder atomization. In conclusion, our data suggest that inhalation therapy with GM spray-dried powders is an effective treatment for pneumonic plague.

Exploration of Dual Ionic Cross-Linked Alginate Hydrogels Via Cations of Varying Valences towards Wound Healing

This study explored the synergistic effects of simultaneously using calcium and gallium cations in the cross-linking of alginate, detailing its effects on the characteristics of alginate compared to its single cation counterparts. The primary goal is to determine if there are any synergistic effects associated with the utilisation of multiple multivalent cations in polymer cross-linking and whether or not it could therefore be used in pharmaceutical applications such as wound healing. Given the fact divalent and trivalent cations have never been utilised together for cross-linking, an explanation for the mode of binding that occurs between the alginate and the cations during the cross-linking process and how it may affect the future applications of the polymer has been investigated. The calcium gallium alginate polymers were able to retain the antibacterial effects of gallium within the confines of the polymer matrix, possessing superior rheological properties, 6 times that of pure calcium and pure gallium, coupled with an improved swelling capacity that is 4 times higher than that of gallium alginate.

Sodium Alginate—Natural Microencapsulation Material of Polymeric Microparticles

From the multitude of materials currently available on the market that can be used in the development of microparticles, sodium alginate has become one of the most studied natural anionic polymers that can be included in controlled-release pharmaceutical systems alongside other polymers due to its low cost, low toxicity, biocompatibility, biodegradability and gelatinous die-forming capacity in the presence of Ca²⁺ ions. In this review, we have shown that through coacervation, the particulate systems for the dispensing of drugs consisting of natural polymers are nontoxic, allowing the repeated administration of medicinal substances and the protection of better the medicinal substances from degradation, which can increase the capture capacity of the drug and extend its release from the pharmaceutical form.

Nanoparticle-Based Inhalation Therapy for Pulmonary Diseases

The lung is exposed to various pollutants and is the primary site for the onset of various diseases, including infections, allergies, and cancers. One possible treatment approach for such pulmonary diseases involves direct administration of therapeutics to the lung so as to maintain the topical concentration of the drug. Particles with nanoscale diameters tend to reach the pulmonary region. Nanoparticles (NPs) have garnered significant interest for applications in biomedical and pharmaceutical industries because of their unique physicochemical properties and biological activities. In this article, we describe the biological and pharmacological activities of NPs as well as summarize their potential in the formulation of drugs employed to treat pulmonary diseases. Recent advances in the use of NPs in inhalation chemotherapy for the treatment of lung diseases have also been highlighted.

The Role of Nrf2 in Pulmonary Fibrosis: Molecular Mechanisms and Treatment Approaches

Pulmonary fibrosis is a chronic, progressive, incurable interstitial lung disease with high mortality after diagnosis and remains a global public health problem. Despite advances and breakthroughs in understanding the pathogenesis of pulmonary fibrosis, there are still no effective methods for the prevention and treatment of pulmonary fibrosis. The existing treatment options are imperfect, expensive, and have considerable limitations in effectiveness and safety. Hence, there is an urgent need to find novel therapeutic targets. The nuclear factor erythroid 2-related factor 2 (Nrf2) is a central regulator of cellular antioxidative responses, inflammation, and restoration of redox balance. Accumulating reports reveal that Nrf2 activators exhibit potent antifibrosis effects and significantly attenuate pulmonary fibrosis in vivo and in vitro. This review summarizes the current Nrf2-related knowledge about the regulatory mechanism and potential therapies in the process of pulmonary fibrosis. Nrf2 orchestrates the activation of multiple protective genes that target inflammation, oxidative stress, fibroblast–myofibroblast differentiation (FMD), and epithelial–mesenchymal transition (EMT), and the mechanisms involve Nrf2 and its downstream antioxidant, Nrf2/HO−1/NQO1, Nrf2/NOX4, and Nrf2/GSH signaling pathway. We hope to indicate potential for Nrf2 system as a therapeutic target for pulmonary fibrosis.

Recent development in nanoencapsulation and delivery of natural bioactives through chitosan scaffolds for various biological applications

Nowadays, nano/micro-encapsulation as a pioneering technique may significantly improve the bioavailability and durability of Natural bioactives. For this purpose, chitosan as a bioactive cationic natural polysaccharide has been frequently used as a carrier because of its distinct chemical and biological properties, including polycationic nature, biocompatibility, and biodegradability. Moreover, polysaccharide-based nano/micro-formulations are a new and extensive trend in scientific research and development in the disciplines of biomedicine, bioorganic/ medicinal chemistry, pharmaceutics, agrochemistry, and the food industry. It promises a new paradigm in drug delivery systems and nanocarrier formulations. This review aims to summarize current developments in approaches for designing innovative chitosan micro/nano-matrix, with an emphasis on the encapsulation of natural bioactives. The special emphasis led to a detailed integrative scientific achievement of the functionalities and abilities for encapsulating natural bioactives and mechanisms regulated in vitro/in vivo release in various biological/physiological environments.

Drug delivery systems for cancer treatment: a review of marine-derived polysaccharides

Abstract:

Cancer is a disease characterized by uncontrolled cell proliferation and the spread of cells to other tissues and remains one of the worldwide problems waiting to be solved. There are various treatment strategies for cancer, such as chemotherapy, surgery, radiotherapy, and immunotherapy, although it varies according to its type and stage. Many chemotherapeutic agents have limited clinical use due to lack of efficacy, off-target toxicity, metabolic instability, or poor pharmacokinetics. One possible solution to this high rate of clinical failure is to design drug delivery systems that deliver drugs in a controlled and specific manner and are not toxic to normal cells. Marine systems contain biodiversity, including components and materials that can be used in biomedical applications and therapy. Biomaterials such as chitin, chitosan, alginate, carrageenan, fucoidan, hyaluronan, agarose, and ulvan obtained from marine organisms have found use in DDSs today. These polysaccharides are biocompatible, non-toxic, biodegradable, and cost-effective, making them ideal raw materials for increasingly complex DDSs with a potentially regulated release. In this review, the contributions of polysaccharides from the marine environment to the development of anticancer drugs in DDSs will be discussed.

Polysaccharide-based formulations as potential carriers for pulmonary delivery - A review of their properties and fates

Polysaccharides can be elite carriers for therapeutic molecules due to their versatility and low probability to trigger toxicity and immunogenic responses. Local and systemic therapies can be achieved through particle pulmonary delivery, a promising non-invasive alternative. Successful pulmonary delivery requires particles with appropriate flowability to reach alveoli and avoid premature clearance mechanisms. Polysaccharides can form micro-, nano-in-micro-, and large porous particles, aerogels, and hydrogels. Herein, the characteristics of polysaccharides used in drug formulations for pulmonary delivery are reviewed, providing insights into structure-function relationships. Charged polysaccharides can confer mucoadhesion, whereas the ability for specific sugar recognition may confer targeting capacity for alveolar macrophages. The method of particle preparation must be chosen considering the properties of the components and the delivery device to be utilized. The fate of polysaccharide-based carriers is dependent on enzyme-triggered hydrolytic and/or oxidative mechanisms, allowing their complete degradation and elimination through urine or reutilization of released monosaccharides.

Surface-engineered smart nanocarrier-based inhalation formulations for targeted lung cancer chemotherapy: a review of current practices

Lung cancer is the second most common and lethal cancer in the world. Chemotherapy is the preferred treatment modality for lung cancer and prolongs patient survival by effective controlling of tumor growth. However, owing to the nonspecific delivery of anticancer drugs, systemic chemotherapy has limited clinical efficacy and significant systemic adverse effects. Inhalation routes, on the other hand, allow for direct delivery of drugs to the lungs in high local concentrations, enhancing their anti-tumor activity with minimum side effects. Preliminary research studies have shown that inhaled chemotherapy may be tolerated with manageable adverse effects such as bronchospasm and cough. Enhancing the anticancer drugs deposition in tumor cells and limiting their distribution to other healthy cells will therefore increase their clinical efficacy and decrease their local and systemic toxicities. Because of the controlled release and localization of tumors, nanoparticle formulations are a viable option for the delivery of chemotherapeutics to lung cancers via inhalation. The respiratory tract physiology and lung clearance mechanisms are the key barriers to the effective deposition and preservation of inhaled nanoparticle formulations in the lungs. Designing and creating smart nanoformulations to optimize lung deposition, minimize pulmonary clearance, and improve cancerous tissue targeting have been the subject of recent research studies. This review focuses on recent examples of work in this area, along with the opportunities and challenges for the pulmonary delivery of smart nanoformulations to treat lung cancers.

Hybrid Hosts Based on Sodium Alginate and Porous Clay Heterostructures for Drug Encapsulation

In this study, some hybrid materials based on sodium alginate (NaAlg) and porous clay heterostructures (PCHs) were investigated as new hosts for 5-Fluorouracil (5-FU) encapsulation. The hybrid hosts were prepared by ionotropic gelation technique using different concentrations of PCHs (1, 3, and 10 wt%) in order to identify the optimal parameters for encapsulation and drug release. The obtained hybrid materials were characterized using FTIR Spectrometry, thermogravimetric analysis (TGA), scanning electron microscopy (SEM), and UV-Vis spectrometry to investigate the interactions of the raw materials involved in the preparation of hybrid hosts, the influence of PCHs concentrations on drug encapsulation efficiency and drug release profile. All the results show that the synthesized hybrid materials were able to load a high amount of 5-FU, the encapsulation efficiency and the release profile being influenced by the concentrations of PCHs.

Covalently coupling doxorubicin to polymeric nanoparticles as potential inhaler therapy: in vitro studies

Lung cancer is the most commonly diagnosed type of cancer worldwide, non-small cell lung cancer accounts for most lung cancers. Doxorubicin is a widely used chemotherapy agent in lung cancer. However, the drug has several undesirable side effects. Here, doxorubicin coupled PEGylated mucoadhesive nanoparticles were designed as a doxorubicin delivery system for pH-triggered release in lung cancer therapy through inhaler administration. Firstly, alginate/chitosan nanoparticles were developed at optimum conditions. Then, PEG diacid bound to structures for doxorubicin binding and providing steric hindrance for phagocytosis. Doxorubicin was linked via an acid-labile amide bond to PEGylated nanoparticles and 444.3 ± 9.2 µg doxorubicin was loaded per mg nanoparticle. Doxorubicin coupled PEG diacid linked alginate/chitosan nanoparticles were checked with FTIR. Hydrodynamic diameter and zeta potential of nanoparticles were measured as 205.7 ± 15.0 nm and -25.17 ± 2.67 mV. The morphology of nanoparticles was evaluated as nearly spherical. Drug release studies were performed both in physiological and acidic media. The drug release from nanoparticles reached 23.6% (pH 5.5) and 18% (pH 7.4) within 48 h. The cytotoxicity experiments were done using A549-luc-C8 cells, also statistical analyzes were carried out. The MTT results indicated the designed drug delivery system possessed anti-tumor efficacy for non-small cell lung cancer therapy.

Inhaled antibiotic-loaded polymeric nanoparticles for the management of lower respiratory tract infections

Lower respiratory tract infections (LRTIs) are one of the leading causes of deaths in the world. Currently available treatment for this disease is with high doses of antibiotics which need to be administered frequently. Instead, pulmonary delivery of drugs has been considered as one of the most efficient routes of drug delivery to the targeted areas as it provides rapid onset of action, direct deposition of drugs into the lungs, and better therapeutic effects at low doses and is self-administrable by the patients. Thus, there is a need for scientists to design more convenient pulmonary drug delivery systems towards the innovation of a novel treatment system for LRTIs. Drug-encapsulating polymer nanoparticles have been investigated for lung delivery which could significantly reduce the limitations of the currently available treatment system for LRTIs. However, the selection of an appropriate polymer carrier for the drugs is a critical issue for the successful formulations of inhalable nanoparticles. In this review, the current understanding of LRTIs, management systems for this disease and their limitations, pulmonary drug delivery systems and the challenges of drug delivery through the pulmonary route are discussed. Drug-encapsulating polymer nanoparticles for lung delivery, antibiotics used in pulmonary delivery and drug encapsulation techniques have also been reviewed. A strong emphasis is placed on the impact of drug delivery into the infected lungs.

Sericin microparticles enveloped with metal-organic networks as a pulmonary targeting delivery system for intra-tracheally treating metastatic lung cancer

Chemotherapy is one of the major approaches for the treatment of metastatic lung cancer. However, systemic chemotherapy is limited by poor therapeutic efficiency and severe toxic side effects, due to the extremely low delivery efficacy and non-specificity of anticancer drugs. Herein, we report a sericin microparticles enveloped with metal-organic networks as a pulmonary delivery system for treating lung metastasis of breast cancer in an animal model. The sericin microparticles (SMPs) were prepared using water in oil (w/o) emulsification method. After doxorubicin (DOX) loading, tannic acid (TA)/ferric irons (Fe3+) based metal organic networks (MON) were coated on the particles to obtain DOX-loaded microparticles (DOX@SMPs-MON). The SMPs-MON with good biocompatibility could effectively encapsulate DOX and sustainably unload cargos in a pH-dependent manner. The DOX-loaded microparticles could be uptaken by 4T1 cells, and effectively kill the cancer cells. In vivo, DOX@SMPs-MON was deposited in the lungs and remained for over 5 days after pulmonary administration. In contrast to conventional DOX treatment that did not show significantly inhibitory effects on lung metastatic tumor, DOX@SMPs-MON markedly decreased the number and size of metastatic nodules in lungs, and the lung weight and appearance were similar to those of healthy mice. In summary, the sericin microparticles with MON wrapping might be a promising pulmonary delivery system for treating lung metastatic cancer.

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.

Hydrogel-Based Controlled Drug Delivery for Cancer Treatment: A Review

As an emerging drug carrier, hydrogels have been widely used for tumor drug delivery. A hydrogel drug carrier can cause less severe side effects than systemic chemotherapy and can achieve sustained delivery of a drug at tumor sites. In addition, hydrogels have excellent biocompatibility and biodegradability and lower toxicity than nanoparticle carriers. Smart hydrogels can respond to stimuli in the environment (e.g., heat, pH, light, and ultrasound), enabling in situ gelation and controlled drug release, which greatly enhance the convenience and efficiency of drug delivery. Here, we summarize the different sizes of hydrogels used for cancer treatment and their related delivery routes, discuss the design strategies for stimuli-responsive hydrogels, and review the research concerning smart hydrogels reported in the past few years.

Evaluating Inhibitory Effects of Paclitaxel and Vitamin D3 Loaded Poly Lactic Glycolic Acid Co-Delivery Nanoparticles on the Breast Cancer Cell Line

Purpose: Paclitaxel (PTX) has transpired as a significant agent in the treatment of breast cancer. Meanwhile, polylactic glycolic acid (PLGA) nanoparticles (NPs) are able to increase the anticancer effect of the PTX in the blood.

Methods: Nano-precipitation was used to prepare the PLGA-PTX-VitD3 co-delivery NPs. Drug loading, encapsulation efficiency, in vitro release profile, cell viability, migration, apoptosis, and bcl2 expression of NPs were evaluated.

Results: The average size of co-delivery NPs was 231 ± 46 nm. Observed was a controlled release of the PTX and vitamin D3 from co-delivery NPs between 0.5 and 240 hours. MTT showed the ability of 8 μg.mL-1 of co-delivery NPs to kill 50 % of the MCF-7; likewise, the co-delivery NPs prevented MCF-7 migration. The co-delivery NPs led 46.35 % MCF-7 to enter primary apoptosis. 60.8% of MCF-7 in the control group were able to enter the G (1) phase of the cell cycle. The co-delivery NPs increased expression of bax. In addition to its higher toxicity against MCF-7 than that of PTX, co-delivery NPs were able to release drugs continuously for a long period, which indeed increased the efficiency of the drugs.

Conclusion: The effect of co-delivery NPs on MCF-7 cell viability was different from that in other drugs. In fact, the co-deliver NPs were able to release drugs continuously for a long time, this could induce primary apoptosis in the MCF-7 and decrease the metastasis and toxicity of drugs.

Engineering Tumor-Targeting Nanoparticles as Vehicles for Precision Nanomedicine

As a nascent and emerging field that holds great potential for precision oncology, nanotechnology has been envisioned to improve drug delivery and imaging capabilities through precise and efficient tumor targeting, safely sparing healthy normal tissue. In the clinic, nanoparticle formulations such as the first-generation Abraxane® in breast cancer, Doxil® for sarcoma, and Onivyde® for metastatic pancreatic cancer, have shown advancement in drug delivery while improving safety profiles. However, effective accumulation of nanoparticles at the tumor site is sub-optimal due to biological barriers that must be overcome. Nanoparticle delivery and retention can be altered through systematic design considerations in order to enhance passive accumulation or active targeting to the tumor site. In tumor niches where passive targeting is possible, modifications in the size and charge of nanoparticles play a role in their tissue accumulation. For niches in which active targeting is required, precision oncology research has identified targetable biomarkers, with which nanoparticle design can be altered through bioconjugation using antibodies, peptides, or small molecule agonists and antagonists. This review is structured to provide a better understanding of nanoparticle engineering design principles with emphasis on overcoming tumor-specific biological barriers.

Recent advances in aerosol gene delivery systems using non-viral vectors for lung cancer therapy

INTRODUCTION

Lung cancer commonly occurs at a high incidence worldwide. Application of aerosol gene delivery systems using various kinds of vectors can improve the patient's quality of life by prolonging the survival rate.

AREAS COVERED

This review provides a recent update on aerosol gene delivery strategies using various kinds of vectors and gene-modification technologies. Peptide-mediated gene therapy achieves specific targeting of cells and highly improves efficacy. Promoter-operating expression and the CRISPR/Cas9 system are novel gene therapy strategies for effective lung cancer treatment. Furthermore, hybrid systems with a combination of vectors or drugs have been recently applied as new trends in gene therapy.

EXPERT OPINION

Although aerosol gene delivery has many advantages, physiological barriers in the lungs pose formidable challenges. Targeted gene delivery and gene-editing technology are promising strategies for lung cancer therapy. These strategies may allow the development of safety and high efficiency for clinical application. Recently, hybrid gene therapy combining novel and specific vectors has been developed as an advanced strategy. Although gene therapy for lung cancer is being actively researched, aerosol gene therapy strategies are currently lacking, and further studies on aerosol gene therapy are needed to treat lung cancer.

Aerosol immunization by alginate coated mycobacterium (BCG/MIP) particles provide enhanced immune response and protective efficacy than aerosol of plain mycobacterium against M.tb. H37Rv infection in mice

Background

With the aim of preparing a more effective, safe and economical vaccine for tuberculosis, inhalable live mycobacterium formulations were evaluated.

Methods

Alginate particles in the size range of 2–4 μm were prepared by encapsulating live Bacille Calmette–Guérin (BCG) and “Mycobacterium indicus pranii” (MIP). These particles were characterized for their size, stability and release profile. Mice were immunized with liquid aerosol or dry powder aerosol (DPA) alginate encapsulated mycobacterium particles and their in-vitro recall response and infection with mycobacterium H37Rv were investigated.

Results

It was found that the DPA of alginate encapsulated mycobacterium particles invoked superior immune response and provided higher protection in mice than the liquid aerosol. The BCG encapsulated in alginate particles (BEAP) and MIP encapsulated in alginate particles (MEAP) were engulfed by bone marrow dendritic cells (BMDCs) and co-localized with lysosome. The MEAP/BEAP activated BMDCs exhibited higher chemotaxis movement and had enhanced ability of antigen presentation to T cells.

The in-vitro recall response of BEAP/MEAP immunized mice when compared in terms of proliferation index and Interferon gamma (IFN-gamma) released by splenocytes and mediastinal lymph node cells was found to be higher than mice immunized by liquid aerosol of BCG/MIP. Finally, different groups of immunized mice were infected with M. tb H37Rv and after 16 weeks the Colony forming units (CFUs) in lung and spleen estimated. The bacilli burden in the BEAP/MEAP immunized mice was significantly less than the respective liquid aerosol immunized mice and the histopathology of BEAP/MEAP immunized mice lungs showed very little damage.

Conclusions

These inhale-able vaccines formulation of alginate coated live mycobacterium are more immunogenic as compared to the aerosol of bacilli and they provide better protection in mice when infected with H37Rv.

Electronic supplementary material

The online version of this article (10.1186/s12879-019-4157-2) contains supplementary material, which is available to authorized users.

Preparation and Characterization of a Dry Powder Inhaler Composed of PLGA Large Porous Particles Encapsulating Gentamicin Sulfate

Purpose: Direct delivery of aminoglycosides to the lungs was under extensive evaluations during the last decades. Because of large particle size, low density and porous structure, large porous particles (LPPs) are versatile carriers for this purpose. In this study, poly (lactic-co-glycolic acid) (PLGA) LPPs encapsulating gentamicin sulfate were prepared and in vitro characteristics of their freeze-dried powder as a dry powder inhaler (DPI) were evaluated.

Methods: To prepare PLGA LPPs, a double emulsification-solvent evaporation method was optimized and gentamicin sulfate was post-loaded in the LPPs. in vitro characteristics including morphological features, thermal behavior, aerodynamic profile and cumulative drug release were evaluated by the scanning electron microscope (SEM), differential scanning calorimetry (DSC), next-generation cascade impactor (NGI) and Franz diffusion cell respectively.

Results: The obtained results revealed that the preparation method was capable to produce spherical large homogenous highly porous particles. 94% of gentamicin sulfate released from LPPs up to 30 minutes. Mass median aerodynamic diameter (MMAD) and fine particle fraction (FPF) were 4.9 µm and 39% respectively.

Conclusion: In this study, dry powder formulation composed of PLGA LPPs encapsulating gentamicin sulfate showed a promising in vitro behavior as a pulmonary delivery carrier. Improvements on the aerodynamic behavior and in vivo evaluations recommended for further developments.

The effective treatment of multi-drug resistant tumors with self-assembling alginate copolymers

Alginates of two different chain lengths were alkyne functionalized on the hydroxyl group, leaving all carboxylic groups intact.

Microencapsulation of microbial canthaxanthin with alginate and high methoxyl pectin and evaluation the release properties in neutral and acidic condition

Canthaxanthin (CX) is an orange-red keto-carotenoid with high antioxidant activity. This functional pigment is sensitive to oxygen, light, pH and heat. In this study, CX was produced by the Dietzia natronolimnaea HS-1 and was encapsulated in Alginate (Alg) and Alg-high methoxyl pectin (HMP) through O/W/O multiple emulsion/external gelation method to developed resistant microparticles among acidic and neutral pHs. Results showed that initial CX concentration had a significant influence on total CX (TCX), surface CX (SCX), microencapsulation efficiency (EE) and particles size. The highest EE% for Alg (60.21 ± 0.18) and Alg-HMP (70.60 ± 0.68) were obtained with CX initial concentration of 11 and 18 μg/mg, respectively. Alg microparticles showed smaller size compare to Alg-HMP microcapsules. Presence of CX in microparticles and good antioxidant activity was confirmed by FT-IR spectroscopy and DPPH assay, respectively. CX in vitro release was 66% and 49% in acidic condition and 76% and 50% in neutral condition for Alg and Alg-HMP, respectively. Thus, Alg-HMP-CX₁₈ microparticles were selected to be used in both neutral and acidic foods such as milk and fermented milks products as an antioxidant and a colorant agent.

Oviposition Deterrent Efficacy and Characteristics of a Botanical Natural Product, Ocimum gratissimum (L.) Oil-Alginate Beads, against Aedes aegypti (L.)

This study was aimed at investigating the oviposition deterrent activity of Ocimum gratissimum (L.) essential oil (O. gratissimum oil) and its product, Ocimum gratissimum (L.)- alginate beads (beads), against Aedes aegypti (Ae. aegypti) mosquitoes. Chemical analysis of O. gratissimum oil obtained by hydrodistillation, using gas chromatography-mass spectroscopy techniques, presented eugenol (67.38%) and Z-β-ocimene (14.95 %) as major constituents. Good characteristics of beads were obtained by the orifice-ionic gelation method with calcium chloride as hardening agent and Tween®20 as emulsifier. The beads exhibited a good spherical shape and good hardness and flexibility with an average size of 1.49 ± 1.36 mm. The oil content, the yield percentage, and the entrapping efficiency were also examined. The beads (formulation code, F2) could prolong the essential oil release until the 10^th d. This beads provided a remarkably longer oviposition deterrence activity against gravid Ae. aegypti with high percentage for 27 d, whereas free O. gratissimum oil showed a short period of time (8 d) in this activity. The stability study showed the stability of oil content and its compositions in storage condition. These results are very affordable approaches to control the dengue fever.

The potential to treat lung cancer via inhalation of repurposed drugs

Lung cancer is a highly invasive and prevalent disease with ineffective first-line treatment and remains the leading cause of cancer death in men and women. Despite the improvements in diagnosis and therapy, the prognosis and outcome of lung cancer patients is still poor. This could be associated with the lack of effective first-line oncology drugs, formation of resistant tumors and non-optimal administration route. Therefore, the repurposing of existing drugs currently used for different indications and the introduction of a different method of drug administration could be investigated as an alternative to improve lung cancer therapy. This review describes the rationale and development of repositioning of drugs for lung cancer treatment with emphasis on inhalation. The review includes the current progress of repurposing non-cancer drugs, as well as current chemotherapeutics for lung malignancies via inhalation. Several potential non-cancer drugs such as statins, itraconazole and clarithromycin, that have demonstrated preclinical anti-cancer activity, are also presented. Furthermore, the potential challenges and limitations that might hamper the clinical translation of repurposed oncology drugs are described.

Effect of Xanthan⁻Chitosan Microencapsulation on the Survival of Lactobacillus acidophilus in Simulated Gastrointestinal Fluid and Dairy Beverage

Lactobacillus acidophilus was encapsulated in xanthan⁻chitosan (XC) and xanthan⁻chitosan⁻xanthan (XCX) polyelectrolyte complex (PEC) gels by extrusion method. The obtained capsules were characterized by X-ray diffraction and FTIR spectroscopy. The effects of microencapsulation on the changes in survival and release behavior of the Lactobacillus acidophilus during exposure to simulated gastric fluid (SGF) and simulated intestinal fluid (SIF) were studied. Encapsulated Lactobacillus acidophilus exhibited a significantly higher resistance to SGF and SIF than non-encapsulated samples. In addition, the viability of free and immobilized cells of Lactobacillus acidophilus incorporated into dairy beverages was assessed for 21 days both at room temperature and in refrigerated storage. The results indicated that xanthan⁻chitosan⁻xanthan (XCX) and xanthan⁻chitosan (XC) significantly (p < 0.05) improved the cell survival of Lactobacillus acidophilus in yogurt during 21 days of storage at 4 and 25 °C, when compared to free cells.

Microcapsules biologically prepared using Perilla frutescens (L.) Britt. essential oil and their use for extension of fruit shelf life

BACKGROUND

Perilla essential oil (EO) possesses high antioxidant, antimicrobial and insecticidal activities, and has proven to be more reliable than chemically synthesized food preservatives. Nevertheless, EOs have disadvantages of facile photo-degradation and oxidation, which limit their use in agriculture and food industries. Microencapsulation technology that generates a polymeric coating surrounding EOs could overcome these disadvantages.

RESULTS

The EO concentration had a significant effect on encapsulation efficiency (EE) and loading capacity (LC). The best encapsulation conditions were obtained with 2% v/v EO, for which EE and LC were 57% and 36%, respectively. EO-loaded microspheres exhibited a crimped surface with phanic lumps by scanning electron microscopy. Thermal stability experiments revealed droplets that began to decompose sharply at 108 °C, with a 61% weight, loss, which was much lower than EOs of 98%. EO-loaded microcapsules demonstrated good antibacterial activity. Strawberry preservation studies showed that EO-loaded microcapsules could significantly inhibit strawberry decay, maintain the quality of strawberries and prolong shelf life.

CONCLUSION

Perilla EO-loaded microcapsules were successfully prepared by ionic gelation and were effective at inhibiting several bacterial strains. EO-alginate microcapsules could effectively delay the volatilization of EO. Perilla EO-loaded microcapsules therefore have potential for use as an antimicrobial and preservative agent in the food industry. © 2017 Society of Chemical Industry.

Preparation, characterization and immunological evaluation of alginate nanoparticles loaded with whole inactivated influenza virus: Dry powder formulation for nasal immunization in rabbits

It has become important to explore more efficient and feasible influenza vaccines, since epidemics of influenza virus cause hundreds of thousands of deaths all around the world. Improving immunogenicity of parentral influenza vaccines has given rise to mucosal delivery routes. In this study, alginate nanoparticles (NPs) were efficiently synthetized by ionic gelation method and influenza virus and CpG ODN or Quillaja Saponin (QS) adjuvants were actively incorporated into alginate NPs. The prepared particles were evaluated for both humoral and cellular immune responses in rabbits' nostrils. The vaccination started with a prime dose and followed by three boosters (two intranasal (IN) on days 45 and 60 and the last dose, intramuscular (IM) on day 75). HAI titer had increased in all the samples; although, only in the group received WV + CPG suspension reached to the protective HAI titer. All the immunized rabbits elicited significantly high sIgA levels on day 75, compared to the negative and the IM groups. At the end of the study, IN administration of CpG ODN adjuvant with virus antigen induced higher IgG level than the groups vaccinated with alginate NPs with or without CpG ODN (P < 0.001). As for the cellular immunity, CpG ODN was capable of inducing significant levels of IL-4 and TNF-α, either through inoculation along with the virus suspension or as incorporated in alginate NPs. According to the obtained data, CpG ODN adjuvant showed higher immunogenic potential as part of a vaccine delivery system than QS. Moreover, applying alginate polymer as a nasal delivery system carrier was not deemed immunogenic against influenza whole virus.

Hybrid inhalable microparticles for dual controlled release of levofloxacin and DNase: physicochemical characterization and in vivo targeted delivery to the lungs

Current medical treatments against recurrent pulmonary infections caused by Pseudomonas aeruginosa, such as cystic fibrosis (CF) disorder, involve the administration of inhalable antibiotics.