Cationic submicron emulsions for pulmonary DNA immunization

Nanoemulsion: An Emerging Novel Technology for Improving the Bioavailability of Drugs

The pharmaceutical sector has made considerable strides recently, emphasizing improving drug delivery methods to increase the bioavailability of various drugs. When used as a medication delivery method, nanoemulsions have multiple benefits. Their small droplet size, which is generally between 20 and 200 nanometers, creates a significant interfacial area for drug dissolution, improving the solubility and bioavailability of drugs that are weakly water-soluble. Additionally, nanoemulsions are a flexible platform for drug administration across various therapeutic areas since they can encapsulate hydrophilic and hydrophobic medicines. Nanoemulsion can be formulated in multiple dosage forms, for example, gels, creams, foams, aerosols, and sprays by using low-cost standard operative processes and also be taken orally, topically, topically, intravenously, intrapulmonary, intranasally, and intraocularly. The article explores nanoemulsion formulation and production methods, emphasizing the role of surfactants and cosurfactants in creating stable formulations. In order to customize nanoemulsions to particular medication delivery requirements, the choice of components and production techniques is crucial in assuring the stability and efficacy of the finished product. Nanoemulsions are a cutting-edge technology with a lot of potential for improving medication bioavailability in a variety of therapeutic contexts. They are a useful tool in the creation of innovative pharmaceutical formulations due to their capacity to enhance drug solubility, stability, and delivery. Nanoemulsions are positioned to play a crucial role in boosting medication delivery and enhancing patient outcomes as this field of study continues to advance.

Potential Applications of Nanoparticles in Improving the Outcome of Lung Cancer Treatment

Lung cancer is managed using conventional therapies, including chemotherapy, radiation therapy, or a combination of both. Each of these therapies has its own limitations, such as the indiscriminate killing of normal as well as cancer cells, the solubility of the chemotherapeutic drugs, rapid clearance of the drugs from circulation before reaching the tumor site, the resistance of cancer cells to radiation, and over-sensitization of normal cells to radiation. Other treatment modalities include gene therapy, immunological checkpoint inhibitors, drug repurposing, and in situ cryo-immune engineering (ICIE) strategy. Nanotechnology has come to the rescue to overcome many shortfalls of conventional therapies. Some of the nano-formulated chemotherapeutic drugs, as well as nanoparticles and nanostructures with surface modifications, have been used for effective cancer cell killing and radio sensitization, respectively. Nano-enabled drug delivery systems act as cargo to deliver the sensitizer molecules specifically to the tumor cells, thereby enabling the radiation therapy to be more effective. In this review, we have discussed the different conventional chemotherapies and radiation therapies used for inhibiting lung cancer. We have also discussed the improvement in chemotherapy and radiation sensitization using nanoparticles.

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

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

Could the Lung Be a Gateway for Amphotericin B to Attack the Army of Fungi?

Fungal diseases are a significant cause of morbidity and mortality worldwide, primarily affecting immunocompromised patients. Aspergillus, Pneumocystis, and Cryptococcus are opportunistic fungi and may cause severe lung disease. They can develop mechanisms to evade the host immune system and colonize or cause lung disease. Current fungal infection treatments constitute a few classes of antifungal drugs with significant fungi resistance development. Amphotericin B (AmB) has a broad-spectrum antifungal effect with a low incidence of resistance. However, AmB is a highly lipophilic antifungal with low solubility and permeability and is unstable in light, heat, and oxygen. Due to the difficulty of achieving adequate concentrations of AmB in the lung by intravenous administration and seeking to minimize adverse effects, nebulized AmB has been used. The pulmonary pathway has advantages such as its rapid onset of action, low metabolic activity at the site of action, ability to avoid first-pass hepatic metabolism, lower risk of adverse effects, and thin thickness of the alveolar epithelium. This paper presented different strategies for pulmonary AmB delivery, detailing the potential of nanoformulation and hoping to foster research in the field. Our finds indicate that despite an optimistic scenario for the pulmonary formulation of AmB based on the encouraging results discussed here, there is still no product registration on the FDA nor any clinical trial undergoing ClinicalTrial.gov.

State-of-the-Art Review of The Application and Development of Various Methods of Aerosol Therapy

Aerosol therapy is a rapidly developing field of science. Due to a number of advantages, the administration of drugs to the body with the use of aerosol therapy is becoming more and more popular. Spraying drugs into the patient's lungs has a significant advantage over other methods of administering drugs to the body, including injection and oral methods. In order to conduct proper and effective aerosol therapy, it is necessary to become familiar with the basic principles and applications of aerosol therapy under various conditions. The effectiveness of inhalation depends on many factors, but most of all on: the physicochemical properties of the sprayed system, the design of the medical inhaler and its correct application, the dynamics of inhalation (i.e. the frequency of breathing and the volume of inhaled air). It is worth emphasizing that respiratory system diseases are one of the most frequently occurring and fastest growing diseases in the world. Accordingly, in recent years, a significant increase in the number of new spraying devices and pharmaceutical drugs for spraying has appeared on the market. It should also be remembered that the process of spraying a liquid is a complicated and complex process, and its efficiency is very often characterized by the use of micro- and macro parameters (including average droplet diameters or the spectrum of droplet diameter distribution). In order to determine the effectiveness of the atomization process and in the delivery of drugs to the patient's respiratory tract, the analysis of the size of the generated aerosol droplets is most often performed. Based on the proposed literature review, it has been shown that many papers dealt with the issues related to aerosol therapy, the selection of an appropriate spraying device, the possibility of modifying the spraying devices in order to increase the effectiveness of inhalation, and the possibility of occurrence of certain discrepancies resulting from the use of various measurement methods to determine the characteristics of the generated aerosol. The literature review presented in the paper was prepared in order to better understand the spraying process. Moreover, it can be helpful in choosing the right medical inhaler for a given liquid with specific rheological properties. The experimental data contained in this study are of great cognitive importance and may be of interest to entities involved in pharmaceutical product engineering (in particular in the case of the production of drugs containing liquids with complex rheological properties).

Nanoemulsions in drug delivery: formulation to medical application

Nanoscale oil-in-water emulsions (NEs), heterogeneous systems of two immiscible liquids stabilized by emulsifiers or surfactants, show great potential in medical applications because of their attractive characteristics for drug delivery. NEs have been explored as therapeutic carriers for hydrophobic compounds via various routes of administration. NEs provide opportunities to improve drug delivery via alternative administration routes. However, deep understanding of the NE manufacturing and functionalization fundamentals, and how they relate to the choice of administration route and pharmacological profile is still needed to ease the clinical translation of NEs. Here, we review the diversity of medical applications for NEs and how that governs their formulation, route of administration, and the emergence of increasing sophistication in NE design for specific application.

Novel polymeric micelles for insect pest control: encapsulation of essential oil monoterpenes inside a triblock copolymer shell for head lice control

BACKGROUND

Essential oil components (EOCs) are molecules with interesting application in pest control, these have been evaluated against different insect pest from more than 100 years, but their practical use is rather limited. Thus, the enhancement of their bioavailability and manageability due to their dispersion in water can open new perspective for the preparation of formulations for the control of insect pest. In this work, we studied the encapsulation of different monoterpenes in a poloxamer shell in order to prepare aqueous formulations that can be used for the development of platforms used in pest control.

METHODS

Micellar systems containing a 5 wt% of poloxamer 407 and 1.25 wt% of the different monoterpenes were prepared. Dynamic Light Scattering (DLS) experiments were carried out to characterize the dispersion of the EOCs in water. The pediculicidal activity of these micellar systems was tested on head lice using an ex vivo immersion test.

RESULTS

The poloxamers allowed the dispersion of EOCs in water due to their encapsulation inside the hydrophobic core of the copolymer micelles. From this study, we concluded that it is possible to make stable micellar systems containing water (>90 wt%), 1.25 wt% of different monoterpenes and a highly safe polymer (5wt% Poloxamer 407). These formulations were effective against head lice with mortality ranging from 30 to 60%, being the most effective emulsions those containing linalool, 1,8-cineole, α-terpineol, thymol, eugenol, geraniol and nonyl alcohol which lead to mortalities above 50%.

DISCUSSION

Since these systems showed good pediculicidal activity and high physicochemical stability, they could be a new route for the green fabrication of biocompatible and biosustainable insecticide formulations.

Kinetics of Oil Exchange in Nanoemulsions Prepared with the Phase Inversion Concentration Method

Nanoemulsions (NEs) are metastable emulsions with droplet sizes between 20 and 100 nm and with a wide range of applications, for example, in polymerization, in pharmaceutical and cosmetic formulations, and as drug delivery systems. Even though they are not in thermodynamic equilibrium, they can be metastable over relatively long times and have the advantage that they can be formed easily by low energy input methods. In particular, the phase inversion concentration (PIC) method allows the formation of NEs by the dilution of a suitable mixture of oil and surfactants with water. In this paper, we investigate the kinetics of the oil exchange process of NEs formed by the PIC method by looking at the exchange of different hydrophobic oils and by employing contrast variation stopped flow small-angle neutron scattering. These experiments demonstrate that this exchange becomes substantially slower by increasing the chain length of the alkane. This indicates a mechanism where monomer exchange is relevant, which would indicate also that for aging one would expect Ostwald ripening to be the determining factor. Such investigations can be carried out in a unique fashion by means of neutron scattering, and the results have important implications for the optimization of NE formulations.

Dry powder inhalable formulations for anti-tubercular therapy

Tuberculosis (TB) is an intracellular infectious disease caused by the airborne bacterium, Mycobacterium tuberculosis. Despite considerable research efforts, the treatment of TB continues to be a great challenge in part due to the requirement of prolonged therapy with multiple high-dose drugs and associated side effects. The delivery of pharmacological agents directly to the respiratory system, following the natural route of infection, represents a logical therapeutic approach for treatment or vaccination against TB. Pulmonary delivery is non-invasive, avoids first-pass metabolism in the liver and enables targeting of therapeutic agents to the infection site. Inhaled delivery also potentially reduces the dose requirement and the accompanying side effects. Dry powder is a stable formulation of drug that can be stored without refrigeration compared to liquids and suspensions. The dry powder inhalers are easy to use and suitable for high-dose formulations. This review focuses on the current innovations of inhalable dry powder formulations of drug and vaccine delivery for TB, including the powder production method, preclinical and clinical evaluations of inhaled dry powder over the last decade. Finally, the risks associated with pulmonary therapy are addressed. A novel dry powder formulation with high percentages of respirable particles coupled with a cost effective inhaler device is an appealing platform for TB drug delivery.

Molecular mechanisms for enhanced DNA vaccine immunogenicity

In the two decades since their initial discovery, DNA vaccines technologies have come a long way. Unfortunately, when applied to human subjects inadequate immunogenicity is still the biggest challenge for practical DNA vaccine use. Many different strategies have been tested in preclinical models to address this problem, including novel plasmid vectors and codon optimization to enhance antigen expression, new gene transfection systems or electroporation to increase delivery efficiency, protein or live virus vector boosting regimens to maximise immune stimulation, and formulation of DNA vaccines with traditional or molecular adjuvants. Better understanding of the mechanisms of action of DNA vaccines has also enabled better use of the intrinsic host response to DNA to improve vaccine immunogenicity. This review summarizes recent advances in DNA vaccine technologies and related intracellular events and how these might impact on future directions of DNA vaccine development.

PEGylated cationic nanoemulsions can efficiently bind and transfect pIDUA in a mucopolysaccharidosis type I murine model

Mucopolysaccharidosis type I (MPS I) is an autosomal disease caused by alpha-L-iduronidase deficiency. This study proposed the use of cationic nanoemulsions as non-viral vectors for a plasmid (pIDUA) containing the gene that codes for alpha-L-iduronidase. Nanoemulsions composed of medium chain triglycerides (MCT)/1,2-dioleoyl-sn-glycero-3-phosphoethanolamine (DOPE)/1,2-dioleoyl-sn-glycero-3-trimethylammonium propane (DOTAP)/1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[amino(polyethylene glycol)-2000] (DSPE-PEG) were prepared by high pressure homogenization. Formulations were prepared by the adsorption or encapsulation of preformed pIDUA-DOTAP complexes into the oil core of nanoemulsions at different charge ratios. pIDUA complexed was protected from enzymatic degradation by DNase I. The physicochemical characteristics of complexes in protein-containing medium were mainly influenced by the presence of DSPE-PEG. Bragg reflections corresponding to a lamellar organization were identified for blank formulations by energy dispersive X-ray diffraction, which could not be detected after pIDUA complexation. The intravenous injection of these formulations in MPS I knockout mice led to a significant increase in IDUA activity (fluorescence assay) and expression (RT-qPCR) in different organs, especially the lungs and liver. These findings were more significant for formulations prepared at higher charge ratios (+4/-), suggesting a correlation between charge ratio and transfection efficiency. The present preclinical results demonstrated that these nanocomplexes represent a potential therapeutic option for the treatment of MPS I.

Lipid-based carriers for pulmonary products: preclinical development and case studies in humans

A number of lipid-based technologies have been applied to pharmaceuticals to modify their drug release characteristics, and additionally, to improve the drug loading for poorly soluble drugs. These technologies, including solid-state lipid microparticles, many of which are porous in nature, liposomes, solid lipid nanoparticles and nanostructured lipid carriers, are increasingly being developed for inhalation applications. This article provides a review of the rationale for the use of these technologies in the pulmonary delivery of drugs, and summarizes the manufacturing processes and their limitations, the in vitro and in vivo performance of these systems, the safety of these lipid-based systems in the lung, and their promise for commercialization.

Emerging applications of nanoparticles for lung cancer diagnosis and therapy

Lung cancer is by far the leading cause of cancer-related mortality worldwide, most of them being active tobacco smokers. Non small cell lung cancer accounts for around 85% to 90% of deaths, whereas the rest is contributed by small cell lung cancer. The extreme lethality of lung cancer arises due to lack of suitable diagnostic procedures for early detection of lung cancer and ineffective conventional therapeutic strategies. In course with desperate attempts to address these issues independently, a multifunctional nanotherapeutic or diagnostic system is being sought as a favorable solution. The manifestation of physiochemical properties of such nanoscale systems is tuned favorably to come up with a versatile cancer cell targeted diagnostic and therapeutic system. Apart from this, the aspect of being at nanoscale by itself confers the system with an advantage of passive accumulation at the site of tumor. This review provides a broad perspective of three major subclasses of such nanoscale therapeutic and diagnostic systems which include polymeric nanoparticles-based approaches, metal nanoparticles-based approaches, and bio-nanoparticles-based approaches. This review work also serves the purpose of gaining an insight into the pros and cons of each of these approaches with a prospective improvement in lung cancer therapeutics and diagnostics.

Influence of phospholipid composition on cationic emulsions/DNA complexes: physicochemical properties, cytotoxicity, and transfection on Hep G2 cells

BACKGROUND

Cationic nanoemulsions have been recently considered as potential delivery systems for nucleic acids. This study reports the influence of phospholipids on the properties of cationic nanoemulsions/DNA plasmid complexes.

METHODS

Nanoemulsions composed of medium-chain triglycerides, stearylamine, egg lecithin or isolated phospholipids, ie, DSPC, DOPC, DSPE, or DOPE, glycerol, and water were prepared by spontaneous emulsification. Gene transfer to Hep G2 cells was analyzed using real-time polymerase chain reaction.

RESULTS

The procedure resulted in monodispersed nanoemulsions with a droplet size and zeta potential of approximately 250 nm and +50 mV, respectively. The complexation of cationic nanoemulsions with DNA plasmid, analyzed by agarose gel retardation assay, was complete when the complex was obtained at a charge ratio of ≥ 1.0. In these conditions, the complexes were protected from enzymatic degradation by DNase I. The cytotoxicity of the complexes in Hep G2 cells, evaluated by MTT assay, showed that an increasing number of complexes led to progressive toxicity. Higher amounts of reporter DNA were detected for the formulation obtained with the DSPC phospholipid. Complexes containing DSPC and DSPE phospholipids, which have high phase transition temperatures, were less toxic in comparison with the formulations obtained with lecithin, DOPC, and DOPE.

CONCLUSION

The results show the effect of the DNA/nanoemulsion complexes composition on the toxicity and transfection results.

Nanomedicine in pulmonary delivery

The lung is an attractive target for drug delivery due to noninvasive administration via inhalation aerosols, avoidance of first-pass metabolism, direct delivery to the site of action for the treatment of respiratory diseases, and the availability of a huge surface area for local drug action and systemic absorption of drug. Colloidal carriers (ie, nanocarrier systems) in pulmonary drug delivery offer many advantages such as the potential to achieve relatively uniform distribution of drug dose among the alveoli, achievement of improved solubility of the drug from its own aqueous solubility, a sustained drug release which consequently reduces dosing frequency, improves patient compliance, decreases incidence of side effects, and the potential of drug internalization by cells. This review focuses on the current status and explores the potential of colloidal carriers (ie, nanocarrier systems) in pulmonary drug delivery with special attention to their pharmaceutical aspects. Manufacturing processes, in vitro/in vivo evaluation methods, and regulatory/toxicity issues of nanomedicines in pulmonary delivery are also discussed.

Preparation and characterization of a lecithin nanoemulsion as a topical delivery system

Purpose of this study was to establish a lecithin nanoemulsion (LNE) without any synthetic surfactant as a topical delivery vehicle and to evaluate its topical delivery potential by the following factors: particle size, morphology, viscosity, stability, skin hydration and skin penetration. Experimental results demonstrated that an increasing concentration of soybean lecithin and glycerol resulted in a smaller size LNE droplet and increasing viscosity, respectively. The droplet size of optimized LNE, with the glycerol concentration above 75% (w/w), changed from 92 (F10) to 58 nm (F14). Additionally, LNE, incorporated into o/w cream, improved the skin hydration capacity of the cream significantly with about 2.5-fold increase when the concentration of LNE reached 10%. LNE was also demonstrated to improve the penetrability of Nile red (NR) dye into the dermis layer, when an o/w cream, incorporated with NR-loaded LNE, applied on the abdominal skin of rat in vivo. Specifically, the arbitrary unit (ABU) of fluorescence in the dermis layer that had received the cream with a NR-loaded LNE was about 9.9-fold higher than the cream with a NR-loaded general emulsion (GE). These observations suggest that LNE could be used as a promising topical delivery vehicle for lipophilic compounds.

Preparation and Evaluation of SEDDS and SMEDDS Containing Carvedilol

A new self-emulsifying drug delivery system (SEDDS) and self-microemulsifying drug delivery system (SMEDDS) have been developed to increase the solubility, dissolution rate, and, ultimately, oral bioavailability of a poorly water soluble drug, carvedilol. Ternary phase diagrams were used to evaluate the self-emulsification and self-microemulsfication domains. The self-emulsification time following introduction into an aqueous medium under gentle agitation was evaluated. The minimum self-emulsification time was found at a Tween 80 content of 40%. The particle size distribution and zeta-potential were determined. Benzoic acid had a dual function, it improved the self-emulsification performance of SEDDS and SMEDDS in 0.1 N HCl and lead to a positively charged emulsion. The in vitro dissolution rate of carvedilol from SEDDS and SMEDDS was more than two-fold faster compared with that from tablets. The developed SEDDS formulations significantly improved the oral bioavailability of carvedilol significantly, and the relative oral bioavailability of SEDDS compared with commercially available tablets was 413%.

Effect of cationic lipid composition on properties of oligonucleotide/emulsion complexes: Physico-chemical and release studies

This paper describes the influence of cationic lipid composition on physico-chemical properties of complexes formed between oligonucleotides (ON) and cationic emulsions. Formulations containing medium chain triglycerides, egg lecithin, increasing amounts of either oleylamine (OA) or 1,2-dioleoyl-3-trimethylammonium-propane (DOTAP), and water were prepared by a spontaneous emulsification procedure. ON adsorption on emulsions was evidenced by the inversion of the zeta-potential, the increase in droplet size, and the morphology of the oil droplet examined through transmission electron microscopy. Adsorption isotherms showed a higher amount of ON adsorbed on emulsions containing DOTAP when compared to emulsions containing OA. In a final step, the role of the main parameters, which may in fact influence the ON release rate from emulsions, was investigated. ON were progressively released from emulsions with an increase in dilution ratio and remained quite similar for both OA and DOTAP emulsions over time. Conversely, the effect of the cationic lipid composition was observed upon increasing the charge ratio of complexes. ON release at a same charge ratio was lower from emulsions containing DOTAP (bearing dioleyl chains) than from those containing OA (bearing monoleyl chain).

Activation of antigen-presenting cells by DNA delivery vectors

Gene-based modulation of immune functions is a promising means of eliciting protective immunity and induction of tolerance. Novel viral and non-viral DNA delivery systems are being investigated to achieve efficient gene transfer into mammalian cells. Antigen-presenting cells (APCs), in particular dendritic cells, are crucial targets in this context due to their capacity to initiate and direct effector functions. The increasing relevance of APCs as targets of DNA vectors calls for an assessment of vector-driven activation of these cells. For viral vectors, a putative pathway of APC activation would be Toll-like receptor signalling for certain RNA genome viruses. On the other hand, non-viral vectors appear to mature APCs by interaction of polymeric particulates or bioactive lipids with cellular mechanisms. The rational design of DNA-based therapies is possible only when the intrinsic effects of the vector and immune modulation originating from the DNA are delineated. This paper will summarise recent reports of adjuvant properties of viral and non-viral delivery systems.

Pulmonary DNA vaccination: concepts, possibilities and perspectives

Mucosal immunity establishes the first line of defence against pathogens entering the body via mucosal surfaces. Besides eliciting both local and systemic immunity, mucosal vaccination strategies that are non-invasive in nature may increase patient compliance and reduce the need for vaccine application by trained personnel. A relatively new concept is mucosal immunization using DNA vaccines. The advantages of DNA vaccines, such as the opportunity to combine the genetic information of various antigen epitopes and stimulatory cytokines, the enhanced stability and ease of production make this class of vaccines attractive and suitable for mucosal application. In contrast to the area of intranasal vaccination, only a few recent studies have focused on pulmonary immunization and the involvement of the pulmonary immune system in eliciting protective immune responses against inhaled pathogens. This review focuses on DNA vaccine delivery to the lung as a promising approach to prevent pulmonary-associated diseases caused by inhaled pathogens. Attractive immunological features of the lung as a site for immunization, the mechanisms of action of DNA vaccines and the pulmonary application of such vaccines using novel delivery systems will be discussed. We also examine pulmonary diseases prone to prevention or therapeutical intervention by application of DNA vaccines.