Solid lipid nanoparticles for pulmonary delivery of insulin

Insight Into Interfacial Behaviors between Doxorubicin and Zwitterion/PAMAM/CQD Hybrid Nanocarrier. A Molecular Dynamics Simulations Study

Poly(amidoamine) dendrimer (PAMAM)/carbon quantum dot (CQD) nanohybrids are promising candidates for many biomedical applications, including drug delivery. Effectively designing a hybrid nanocarrier requires a deep understanding of the interactions of the hybrid nanoparticle with the drug to ensure drug stability and therapeutic efficiency. In this study, we utilized fully atomistic molecular dynamics (MD) simulations to investigate the adsorption behavior of a doxorubicin (DOX) anticancer drug onto a zwitterion/PAMAM/CQD hybrid nanocarrier. The hybrid nanoparticles were composed of CQD, at two oxidation levels, grafted with PAMAM dendrimers of generation 3 (G3) or 4 (G4) decorated with zwitterion monomers. Our work reveals that the generation of the grafted dendrimer was the primary determinant of efficient adsorption of DOX, unlike the oxidation level of CQD or dendrimer surface chemistry. After grafting, the G4 dendrimers assume a more stretched conformation compared to the G3 dendrimers. This allowed DOX molecules to penetrate inside the dendritic cavities of G4 dendrimers, resulting in enhanced drug protection. The hydrophobic interaction, between the aromatic structure of DOX molecules and the nonpolar parts of dendrimers, has been proven to play a crucial role in mediating the adsorption of drug molecules. These findings provide valuable insights to assist in the design of a zwitterion/PAMAM/CQD hybrid nanoplatform for drug delivery applications.

Enhancing pulmonary delivery and immunomodulation of respiratory diseases through virus-mimicking nanoparticles

This study introduces the nanobromhexine lipid particle (NBL) platform designed for effective pulmonary drug delivery. Inspired by respiratory virus transport mechanisms, NBL address challenges associated with mucus permeation and inflammation in pulmonary diseases. Composed of low molecular weight polyethylene glycol-coated lipid nanoparticles with bromhexine hydrochloride, NBL exhibit a size of 118 ± 24 nm, a neutral zeta potential, osmolarity of 358 ± 28 mOsmol/kg, and a pH of 6.5. Nebulizing without leakage and showing no toxicity to epithelial cells, NBL display mucoadhesive properties with a 60% mucin-binding efficiency. They effectively traverse the dense mucus layer of Calu-3 cultures in an air-liquid interface, as supported by a 55% decrease in MUC5AC density and a 29% increase in nanoparticles internalization compared to non-exposed cells. In assessing immunomodulatory effects, NBL treatment in SARS-CoV-2-infected lung cells leads to a 40-fold increase in anti-inflammatory MUC1 gene expression, a proportional reduction in pro-inflammatory IL-6 expression, and elevated anti-inflammatory IL-10 expression. These findings suggest a potential mechanism to regulate the excessive IL-6 expression triggered by virus infection. Therefore, the NBL platform demonstrates promising potential for efficient pulmonary drug delivery and immunomodulation, offering a novel approach to addressing mucus permeation and inflammation in pulmonary diseases.

Inhalable solid lipid nanoparticles of levofloxacin for potential tuberculosis treatment

Delivering novel antimycobacterial agents through the pulmonary route using nanoparticle-based systems shows promise for treating diseases like tuberculosis. However, creating dry powder inhaler (DPI) with suitable aerodynamic characteristics while preserving nanostructure integrity and maintaining bioactivity until the active ingredient travels deeply into the lungs is a difficult challenge. We developed DPI formulations containing levofloxacin-loaded solid lipid nanoparticles (SLNs) via spray-drying technique with tailored aerosolization characteristics for effective inhalation therapy. A range of biophysical techniques, including transmission electron microscopy, confocal microscopy, and scanning electron microscopy were used to measure the morphologies and sizes of the spray-dried microparticles that explored both the geometric and aerodynamic properties. Spray drying substantially reduced the particle sizes of the SLNs while preserving their nanostructural integrity and enhancing aerosol dispersion with efficient mucus penetration. Despite a slower uptake rate compared to plain SLNs, the polyethylene glycol modified formulations exhibited enhanced cellular uptake in both A549 and NR8383 cell lines. The percent viability of Mycobacterium bovis had dropped to nearly 0 % by day 5 for both types of SLNs. Interestingly, the levofloxacin-loaded SLNs demonstrated a lower minimum bactericidal concentration (0.25 µg/mL) compared with pure levofloxacin (1 µg/mL), which indicated the formulations have potential as effective treatments for tuberculosis.

Bibliometric analysis of research on the utilization of nanotechnology in diabetes mellitus and its complications

Aim: To identify hotspots in this field and provide insights into future research directions. Methods: Publications were retrieved from the Web of Science Core Collection database. R Bibliometrix software, VOSviewer and CiteSpace were used to perform the bibliometric and visualization analyses. Results: The analysis comprised 468 publications from 58 countries, with the United States, China and India being the leading contributors. 'Gene therapy', 'nanoparticles' and 'insulin therapy' are the primary focuses. 'Green synthesis', 'cytotoxicity', 'bioavailability' and 'diabetic foot ulcers' have gained prominence, signifying high-intensity areas of interest expected to persist as favored research topics in the future. Conclusion: This study delves into recent frontiers and topical research directions and provides valuable references for further research in this field.

Solid Lipid Nanoparticles for Pulmonary Delivery of Biopharmaceuticals: A Review of Opportunities, Challenges, and Delivery Applications

Biopharmaceuticals such as nucleic acids, proteins, and peptides constitute a new array of treatment modalities for chronic ailments. Invasive routes remain the mainstay of administering biopharmaceuticals due to their labile nature in the biological environment. However, it is not preferred for long-term therapy due to the lack of patient adherence and clinical suitability. Therefore, alternative routes of administration are sought to utilize novel biopharmaceutical therapies to their utmost potential. Nanoparticle-mediated pulmonary delivery of biologics can facilitate both local and systemic disorders. Solid lipid nanoparticles (SLNs) afford many opportunities as pulmonary carriers due to their physicochemical stability and ability to incorporate both hydrophilic and hydrophobic moieties, thus allowing novel combinatorial drug/gene therapies. These applications include pulmonary infections, lung cancer, and cystic fibrosis, while systemic delivery of biomolecules, like insulin, is also attractive for the treatment of chronic ailments. This Review explores physiological and particle-associated factors affecting pulmonary delivery of biopharmaceuticals. It compares the advantages and limitations of SLNs as pulmonary nanocarriers along with design improvements underway to overcome these limitations. Current research illustrating various SLN designs to deliver proteins, peptides, plasmids, oligonucleotides, siRNA, and mRNA is also summarized.

Investigation of Factors Influencing the Effectiveness of Deformable Nanovesicles for Insulin Nebulization Inhalation

Nebulized inhalation offers a noninvasive method for delivering drugs to treat both local respiratory and systemic diseases. In this study, insulin was used as a model drug to design a series of deformable nanovesicles (DNVs) with key quality attributes, including particle size, deformability, and drug load capacity. We investigated the effects of these properties on aerosol generation, macrophage phagocytosis, and bloodstream penetration. The results showed that deformability improved nebulization performance and reduced macrophage phagocytosis, benefiting local and systemic delivery. However, the advantage of DNVs for transmembrane penetration was not evident in the alveolar epithelium. Within the size range of 80-490 nm, the smaller the particle size of IPC-DNVs, the easier it is to evade clearance by macrophages and the more effective the in vivo hypoglycemic efficacy will be. In the drug load range of 3-5 mg/mL, a lower drug load resulted in better hypoglycemic efficacy. The area above the blood glucose decline curve with time (AAC) of nebulized DNVs was 2.32 times higher than that of the insulin solution, demonstrating the feasibility and advantages of DNVs in the pulmonary delivery of biomacromolecule drugs. This study provides insights into the construction and formulation optimization of pulmonary delivery carriers.

A Review on Micro and Nanoengineering in Powder-Based Pulmonary Drug Delivery

Pulmonary delivery of drugs has emerged as a promising approach for the treatment of both lung and systemic diseases. Compared to other drug delivery routes, inhalation offers numerous advantages including high targeting, fewer side effects, and a huge surface area for drug absorption. However, the deposition of drugs in the lungs can be limited by lung defence mechanisms such as mucociliary and macrophages' clearance. Among the delivery devices, dry powder inhalers represent the optimal choice due to their stability, ease of use, and absence of propellants. In the last decades, several bottom-up techniques have emerged over traditional milling to produce inhalable powders. Among these techniques, the most employed ones are spray drying, supercritical fluid technology, spray freeze-drying, and thin film freezing. Inhalable dry powders can be constituted by micronized drugs attached to a coarse carrier (e.g., lactose) or drugs embedded into a micro- or nanoparticle. Particulate-based formulations are commonly composed of polymeric micro- and nanoparticles, liposomes, solid lipid nanoparticles, dendrimers, nanocrystals, extracellular vesicles, and inorganic nanoparticles. Moreover, engineered formulations including large porous particles, swellable microparticles, nano-in-microparticles, and effervescent nanoparticles have been developed. Particle engineering has also a crucial role in tuning the physical-chemical properties of both carrier-based and carrier-free inhalable powders. This approach can increase powder flowability, deposition, and targeting by customising particle surface features.

Excipients for Novel Inhaled Dosage Forms: An Overview

Pulmonary drug delivery is a form of local targeting to the lungs in patients with respiratory disorders like cystic fibrosis, pulmonary arterial hypertension (PAH), asthma, chronic pulmonary infections, and lung cancer. In addition, noninvasive pulmonary delivery also presents an attractive alternative to systemically administered therapeutics, not only for localized respiratory disorders but also for systemic absorption. Pulmonary delivery offers the advantages of a relatively low dose, low incidence of systemic side effects, and rapid onset of action for some drugs compared to other systemic administration routes. While promising, inhaled delivery of therapeutics is often complex owing to factors encompassing mechanical barriers, chemical barriers, selection of inhalation device, and limited choice of dosage form excipients. There are very few excipients that are approved by the FDA for use in developing inhaled drug products. Depending upon the dosage form, and inhalation devices such as pMDIs, DPIs, and nebulizers, different excipients can be used to provide physical and chemical stability and to deliver the dose efficiently to the lungs. This review article focuses on discussing a variety of excipients that have been used in novel inhaled dosage forms as well as inhalation devices.

Efficacy of oral insulin nanoparticles for the management of hyperglycemia in a rat model of diabetes induced with streptozotocin

Insulin is the cornerstone of treatment in type 1 diabetes mellitus. However, because of its protein structure, insulin has to be administered via injection, and many attempts have been made to create oral formulations, especially using nanoparticles (NPs). The aim of this study was to compare the hypoglycemic effect of insulin-loaded NPs to that of subcutaneous insulin in an in vivo rat model of diabetes. We used biodegradable D-α-tocopherol polyethylene glycol succinate-emulsified, chitosan-capped poly(lactic-co-glycolic acid) NPs loaded with soluble human insulin in a dose of 20 IU/kg body weight, and examined the physical characteristics of NPs in vivo and in vitro. Serum glucose levels were reduced after 6 h, but the difference was not significant compared to subcutaneous insulin; at 12 h and 24 h, insulin levels were significantly higher in rats treated with NPs than in rats treated with subcutaneous insulin. There was no significant difference in serum insulin levels at 12 h and 24 h compared to non-diabetic rats. Our findings suggest that chitosan-based NPs are able to maintain good glycemic control for up to 24 h and can be considered a potential carrier for oral insulin delivery.

Nano-platform Strategies of Herbal Components for the Management of Rheumatoid Arthritis: A Review on the Battle for Next-Generation Formulations

INTRODUCTION

Rheumatoid arthritis (RA) is a chronic inflammatory autoimmune disease that initially affects small joints and then spreads to the bigger joints. It also affects other organs of the body such as lungs, eyes, kidneys, heart, and skin. In RA, there is destruction of cartilage and joints, and ligaments and tendons become brittle. Damage to the joints leads to abnormalities and bone degradation, which may be quite painful for the patient.

METHOD

The nano-carriers such as liposomes, phytosomes, nanoparticles, microcapsules, and niosomes are developed to deliver the encapsulated phytoconstituents to targeted sites for the better management of RA.

RESULTS

The phytoconstituents loaded nano-carriers have been used in order to increase bioavailability, stability and reduce the dose of an active compound. In one study, the curcumin-loaded phytosomes increase the bioavailability of curcumin and also provides relief from RA symptoms. The drug-loaded nano-carriers are the better option for the management of RA.

CONCLUSION

In conclusion, there are many anti-arthritic herbal and synthetic medicine available in the market that are currently used in the treatment of RA. However, chronic use of these medications may result in a variety of side effects. Because therapy for RA is frequently necessary for the rest of ones life. The use of natural products may be a better option for RA management. These phytoconstituents, however, have several disadvantages, including limited bioavailability, low stability, and the need for a greater dosage. These problems can be rectified by using nano-technology.

Several Applications of Solid Lipid Nanoparticles in Drug Delivery

Rapid progress is being made in the area of nanotechnology; solid lipid nanoparticles are currently at the forefront of research and development. They have the capability of becoming employed in an extensive number of applications, including the delivery of medications, clinical treatment, and research, in addition to uses in other areas of academic inquiry that could benefit from their utilisation. This article presents a thorough analysis of solid lipid nanoparticles, covering subjects such as their goals, preparation strategy, applications, advantages, and possible remedies for the issues that have been raised. This review provides a discussion of solid lipids that is both in-depth and comprehensive. Studies that investigate the manner in which SLNs are prepared and the routes via which they are administered are typical. Aspects concerning the route of administration of SLNs as well as the destiny of the carriers in vivo are also investigated in this paper.

Self-assembled block copolymer biomaterials for oral delivery of protein therapeutics

Protein therapeutics have guided a transformation in disease treatment for various clinical conditions. They have been successful in numerous applications, but administration of protein therapeutics has been limited to parenteral routes which can decrease patient compliance as they are invasive and painful. In recent years, the synergistic relationship of novel biomaterials with modern protein therapeutics has been crucial in the treatment of diseases that were once thought of as incurable. This has guided the development of a variety of alternative administration routes, but the oral delivery of therapeutics remains one of the most desirable due to its ease of administration. This review addresses important aspects of micellar structures prepared by self-assembled processes with applications for oral delivery. These two characteristics have not been placed together in previous literature within the field. Therefore, we describe the barriers for delivery of protein therapeutics, and we concentrate in the oral/transmucosal pathway where drug carriers must overcome several chemical, physical, and biological barriers to achieve a successful therapeutic effect. We critically discuss recent research on biomaterials systems for delivering such therapeutics with an emphasis on self-assembled synthetic block copolymers. Polymerization methods and nanoparticle preparation techniques are similarly analyzed as well as relevant work in this area. Based on our own and others' research, we analyze the use of block copolymers as therapeutic carriers and their promise in treating a variety of diseases, with emphasis on self-assembled micelles for the next generation of oral protein therapeutic systems.

Hybrid Nanoplatforms Comprising Organic Nanocompartments Encapsulating Inorganic Nanoparticles for Enhanced Drug Delivery and Bioimaging Applications

Organic and inorganic nanoparticles (NPs) have attracted significant attention due to their unique physico-chemical properties, which have paved the way for their application in numerous fields including diagnostics and therapy. Recently, hybrid nanomaterials consisting of organic nanocompartments (e.g., liposomes, micelles, poly (lactic-co-glycolic acid) NPs, dendrimers, or chitosan NPs) encapsulating inorganic NPs (quantum dots, or NPs made of gold, silver, silica, or magnetic materials) have been researched for usage in vivo as drug-delivery or theranostic agents. These classes of hybrid multi-particulate systems can enable or facilitate the use of inorganic NPs in biomedical applications. Notably, integration of inorganic NPs within organic nanocompartments results in improved NP stability, enhanced bioavailability, and reduced systemic toxicity. Moreover, these hybrid nanomaterials allow synergistic interactions between organic and inorganic NPs, leading to further improvements in therapeutic efficacy. Furthermore, these platforms can also serve as multifunctional agents capable of advanced bioimaging and targeted delivery of therapeutic agents, with great potential for clinical applications. By considering these advancements in the field of nanomedicine, this review aims to provide an overview of recent developments in the use of hybrid nanoparticulate systems that consist of organic nanocompartments encapsulating inorganic NPs for applications in drug delivery, bioimaging, and theranostics.

Solid Lipid Nanoparticles: Multitasking Nano-Carriers for Cancer Treatment

Despite all the advances seen in recent years, the severe adverse effects and low specificity of conventional chemotherapy are still challenging problems regarding cancer treatment. Nanotechnology has helped to address these questions, making important contributions in the oncological field. The use of nanoparticles has allowed the improvement of the therapeutic index of several conventional drugs and facilitates the tumoral accumulation and intracellular delivery of complex biomolecules, such as genetic material. Among the wide range of nanotechnology-based drug delivery systems (nanoDDS), solid lipid nanoparticles (SLNs) have emerged as promising systems for delivering different types of cargo. Their solid lipid core, at room and body temperature, provides SLNs with higher stability than other formulations. Moreover, SLNs offer other important features, namely the possibility to perform active targeting, sustained and controlled release, and multifunctional therapy. Furthermore, with the possibility to use biocompatible and physiologic materials and easy scale-up and low-cost production methods, SLNs meet the principal requirements of an ideal nanoDDS. The present work aims to summarize the main aspects related to SLNs, including composition, production methods, and administration routes, as well as to show the most recent studies about the use of SLNs for cancer treatment.

Opposites Attract: Electrostatically Driven Loading of Antimicrobial Peptides into Phytoglycogen Nanocarriers

Antimicrobial peptides, such as GL13K, have a high binding selectivity toward bacterial membranes, while not affecting healthy mammalian cells at therapeutic concentrations. However, delivery of these peptides is challenging since they are susceptible to proteolytic hydrolysis and exhibit poor cellular uptake. A protective nanocarrier is thus proposed to overcome these obstacles. We investigate the potential to employ biodegradable phytoglycogen nanoparticles as carriers for GL13K using a simple loading protocol based on electrostatic association rather than chemical conjugation, eliminating the need for control of chemical cleavage for release of the peptide in situ. Both the native (quasi-neutral) and carboxymethylated (anionic) phytoglycogen were evaluated for their colloidal stability, loading capacity, and release characteristics. We show that the anionic nanophytoglycogen carries a greater cationic GL13K load and exhibits slower release kinetics than native nanophytoglycogen. Isotope exchange measurements demonstrate that the antimicrobial peptide is entrapped in the pores of the dendritic-like macromolecule, which should provide the necessary protection for delivery. Importantly, the nanoformulations are active against a Pseudomonas aeruginosa clinical isolate at concentrations comparable to those of the free peptide and representative, small molecule antibiotics. The colloidal nanocarrier preserves peptide stability and antimicrobial activity, even after long periods of storage (at least 8 months).

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.

Solid lipid nanoparticles: a promising tool for insulin delivery

INTRODUCTION

Insulin plays a critical role in metabolism modulation including carbohydrate, lipid, and protein metabolism. There is room to improve insulin delivery but optimizing the best carrier remains challenging. Traditional and conventional approaches for insulin delivery do not emulate the normal fate of insulin release in the body. Despite extensive research attempts to overcome this and other challenges, the goal of achieving optimal insulin delivery that emulates the natural system remains unresolved.

AREAS COVERED

Solid Lipid Nanoparticles (SLNs) may provide a solution, because they are nontoxic, biocompatible, and straightforward to formulate thus providing a promising platform for achieving targeted and controlled delivery of various therapeutic agents. This review aims to provide an overview on the suitability and application of SLNs for insulin delivery. A special emphasis is placed on the biopharmaceutical aspects of insulin loaded SLNs which have not been explored in detail to date.

EXPERT OPINION

SLNs have proven to be safe and versatile drug delivery systems suitable for insulin delivery and capable of improving the efficacy and pharmacokinetic profile of encapsulated insulin. There is still some work to be done to fully explore SLNs' true potential as drug delivery and specifically insulin delivery vehicles suitable for clinical use.

Lipid Nanoparticles as Delivery Vehicles for Inhaled Therapeutics

Lipid nanoparticles (LNPs) have emerged as a powerful non-viral carrier for drug delivery. With the prevalence of respiratory diseases, particularly highlighted by the current COVID-19 pandemic, investigations into applying LNPs to deliver inhaled therapeutics directly to the lungs are underway. The progress in LNP development as well as the recent pre-clinical studies in three main classes of inhaled encapsulated drugs: small molecules, nucleic acids and proteins/peptides will be discussed. The advantages of the pulmonary drug delivery system such as reducing systemic toxicity and enabling higher local drug concentration in the lungs are evaluated together with the challenges and design considerations for improved formulations. This review provides a perspective on the future prospects of LNP-mediated delivery of inhaled therapeutics for respiratory diseases.

A story of peptides, lipophilicity and chromatography - back and forth in time

Peptides, as part of the beyond the rule of 5 (bRo5) chemical space, represent a unique class of pharmaceutical compounds. Because of their exceptional position in the chemical space between traditional small molecules (molecular weight (MW) < 500 Da) and large therapeutic proteins (MW > 5000 Da), peptides became promising candidates for targeting challenging binding sites, including even targets traditionally considered as undruggable - e.g. intracellular protein-protein interactions. However, basic knowledge about physicochemical properties that are important for a drug to be membrane permeable is missing but would enhance the drug discovery process of bRo5 molecules. Consequently, there is a demand for quick and simple lipophilicity determination methods for peptides. In comparison to the traditional lipophilicity determination methods via shake flask and in silico prediction, chromatography-based methods could have multiple benefits such as the requirement of low analyte amount, insensitivity to impurities and high throughput. Herein we elucidate the role of peptide lipophilicity and different lipophilicity values. Further, we summarize peptide analysis via common chromatographic techniques, in specific reversed phase liquid chromatography, hydrophilic interaction liquid chromatography and supercritical fluid chromatography and their role in drug discovery and development process.

Taking leads out of nature, can nano deliver us from COVID-like pandemics?

The COVID-19 crisis has alerted the research community to re-purpose scientific tools that can effectively manage emergency pandemic situations. Researchers were never so desperate to discover a 'magic bullet' that has significant clinical benefits with minimal or no side effects. At the beginning of the pandemic, due to restricted access to traditional laboratory techniques, many research groups delved into computational screening of thousands of lead molecules that could inhibit SARS-CoV-2 at one or more stages of its infectious cycle. Several in silico studies on natural derivatives point out their potency against SARS-CoV-2 proteins. However, theoretical predictions and existing knowledge on related molecules reflect their poor oral bioavailability due to biotransformation in the gut and liver. Nanotechnology has evolved into a key field for precise and controlled delivery of various drugs that lack aqueous solubility, have low oral bioavailability and possess pronounced toxicity in their native form. In this review, we discuss various nanoformulations of natural products with favorable ADME properties, and also briefly explore nano-drug delivery to lungs, the primary site of SARS-CoV-2 infection. Natural products are also envisioned to augment nanotechnology-based 1) personnel protective equipment for ex vivo viral inactivation and 2) wearable sensors that perform rapid and non-invasive analysis of volatile organic compounds in exhaled breath of the infected person after therapeutic food consumption.

Insulin Granule-Loaded MicroPlates for Modulating Blood Glucose Levels in Type-1 Diabetes

Type-1 diabetes (T1DM) is a chronic metabolic disorder resulting from the autoimmune destruction of β cells. The current standard of care requires multiple, daily injections of insulin and accurate monitoring of blood glucose levels (BGLs); in some cases, this results in diminished patient compliance and increased risk of hypoglycemia. Herein, we engineered hierarchically structured particles comprising a poly(lactic-co-glycolic) acid (PLGA) prismatic matrix, with a 20 × 20 μm base, encapsulating 200 nm insulin granules. Five configurations of these insulin-microPlates (INS-μPLs) were realized with different heights (5, 10, and 20 μm) and PLGA contents (10, 40, and, 60 mg). After detailed physicochemical and biopharmacological characterizations, the tissue-compliant 10H INS-μPL, realized with 10 mg of PLGA, presented the most effective release profile with ∼50% of the loaded insulin delivered at 4 weeks. In diabetic mice, a single 10H INS-μPL intraperitoneal deposition reduced BGLs to that of healthy mice within 1 h post-implantation (167.4 ± 49.0 vs 140.0 ± 9.2 mg/dL, respectively) and supported normoglycemic conditions for about 2 weeks. Furthermore, following the glucose challenge, diabetic mice implanted with 10H INS-μPL successfully regained glycemic control with a significant reduction in AUC_0-120min (799.9 ± 134.83 vs 2234.60 ± 82.72 mg/dL) and increased insulin levels at 7 days post-implantation (1.14 ± 0.11 vs 0.38 ± 0.02 ng/mL), as compared to untreated diabetic mice. Collectively, these results demonstrate that INS-μPLs are a promising platform for the treatment of T1DM to be further optimized with the integration of smart glucose sensors.

Therapeutic Potential of Thymoquinone and Its Nanoformulations in Pulmonary Injury: A Comprehensive Review

As a crucial organ, the lung is exposed to various harmful agents that may induce inflammation and oxidative stress, which may cause chronic or acute lung injury. Nigella sativa, also known as black seed, has been widely used to treat various diseases and is one of the most extensively researched medicinal plants. Thymoquinone (TQ) is the main component of black seed volatile oil and has been proven to have antioxidant, anti-inflammatory, and antineoplastic properties. The potential therapeutic properties of TQ against various pulmonary disorders have been studied in both in vitro and in vivo studies. Furthermore, the application of nanotechnology may increase drug solubility, cellular absorption, drug release (sustained or control), and drug delivery to lung tissue target sites. As a result, fabricating TQ as nanoparticles (NPs) is a potential therapeutic approach against a variety of lung diseases. In this current review, we summarize recent findings on the efficacy of TQ and its nanotypes in lung disorders caused by immunocompromised conditions such as cancer, diabetes, gastric ulcers, and other neurodegenerative diseases. It is concluded that TQ nanoparticles with anti-inflammatory, antioxidant, antiasthma, and antitumor activity may be safely applied to treat lung disorders. However, more research is required before TQ nanoparticles can be used as pharmaceutical preparations in human studies.

Lipid Nanoparticles as Carriers for Bioactive Delivery

Nanotechnology has made a great impact on the pharmaceutical, biotechnology, food, and cosmetics industries. More than 40% of the approved drugs are lipophilic and have poor solubility. This is the major rate-limiting step that influences the release profile and bioavailability of drugs. Several approaches have been reported to administer lipophilic drugs with improved solubility and bioavailability. Nanotechnology plays a crucial role in the targeted delivery of poorly soluble drugs. Nanotechnology-based drug delivery systems can be classified as solid lipid nanoparticulate drug delivery systems, emulsion-based nanodrug delivery systems, vesicular drug delivery systems, etc. Nanotechnology presents a new frontier in research and development to conquer the limitations coupled with the conventional drug delivery systems through the formation of specific functionalized particles. This review presents a bird's eye view on various aspects of lipid nanoparticles as carriers of bioactive molecules that is, synthesis, characterization, advantage, disadvantage, toxicity, and application in the medical field. Update on recent development in terms of patents and clinical trials of solid lipid nanoparticles (SLNs) and nanostructure lipid carriers (NLCs) have also been discussed in this article.

Fabrication, characterization and optimization of nanostructured lipid carrier formulations using Beclomethasone dipropionate for pulmonary drug delivery via medical nebulizers

Aerosolization is a non-invasive approach in drug delivery for localized and systemic effect. Nanostructured lipid carriers (NLCs) are new generation versatile carriers, which offer protection from degradation and enhance bioavailability of poorly water soluble drugs. The aim of this study was to develop and optimize NLC formulations in combination with optimized airflow rates (i.e. 60 and 15 L/min) and choice of medical nebulizers including Air jet, Vibrating mesh and Ultrasonic nebulizer for superior aerosolization performance, assessed via a next generation impactor (NGI). Novel composition and combination of NLC formulations (F1 - F15) were prepared via ultrasonication method, employing five solid lipids (glycerol trimyristate (GTM), glycerol trilaurate (GTL), cetyl palmitate (CP), glycerol monostearate (GMS) and stearic acid (SA)); and three liquid lipids (glyceryl tributyrate (GTB), propylene glycol dicaprylate/dicaprate (PGD) and isopropyl palmitate (IPP)) in 1:3 w/w ratios (i.e. combination of one solid and one liquid lipid), with Beclomethasone dipropionate (BDP) incorporated as the model drug. Out of fifteen BDP-NLC formulations, the physicochemical properties of formulations F7, F8 and F10 exhibited desirable stability (one week at 25 °C), with associated particle size of ~241 nm, and >91% of drug entrapment. Post aerosolization, F10 was observed to deposit notably smaller sized particles (from 198 to 136 nm, 283 to 135 nm and 239 to 157 nm for Air jet, Vibrating mesh and Ultrasonic nebulizers, respectively) in all stages (i.e. from stage 1 to 8) of the NGI, when compared to F7 and F8 formulations. Six week stability studies conducted at 4, 25 and 45 °C, demonstrated F10 formulation stability in terms of particle size, irrespective of temperature conditions. Nebulizer performance study using the NGI for F10 identified the Air jet to be the most efficient nebulizer, depositing lower concentrations of BDP in the earlier stages (1-3) and higher (circa 82 and 85%) in the lateral stages (4-8) using 60 and 15 L/min airflow rates, when compared to the Vibrating mesh and Ultrasonic nebulizers. Moreover, at both airflow rates, the Air jet nebulizer elicited a longer nebulization time of ~42 min, facilitating aerosol inhalation for prophylaxis of asthma with normal tidal breathing. Based on characterization and nebulizer performance employing both 60 and 15 L/min airflow rates, the Air jet nebulizer offered enhanced performance, exhibiting a higher fine particle dose (FPD) (90 and 69 µg), fine particle fraction (FPF) (70 and 54%), respirable fraction (RF) (92 and 69%), and lower mass median aerodynamic diameter (MMAD) (1.15 and 1.62 µm); in addition to demonstrating higher drug deposition in the lateral parts of the NGI, when compared to its counterpart nebulizers. The F10 formulation used with the Air jet nebulizer was identified as being the most suitable combination for delivery of BDP-NLC formulations.

Self-Assembled chitosan/phospholipid nanoparticles: from fundamentals to preparation for advanced drug delivery

With the development of nanotechnology, self-assembled chitosan/phospholipid nanoparticles (SACPNs) show great promise in a broad range of applications, including therapy, diagnosis, in suit imaging and on-demand drug delivery. Here, a brief review of the SACPNs is presented, and its critical underlying formation mechanisms are interpreted with an emphasis on the intrinsic physicochemical properties. The state-of-art preparation methods of SACPNs are summarized, with particular descriptions about the classic solvent injection method. Then SACPNs microstructures are characterized, revealing the unique spherical core-shell structure and the drug release mechanisms. Afterwards, a comprehensive and in-depth depiction of their emerging applications, with special attention to drug delivery areas, are categorized and reviewed. Finally, conclusions and outlooks on further advancing the SACPNs toward a more powerful and versatile platform for investigations covering from fundamental understanding to developing multi-functional drug delivery systems are discussed.

Formulating SLN and NLC as Innovative Drug Delivery Systems for Non-Invasive Routes of Drug Administration

Colloidal carriers diverge depending on their composition, ability to incorporate drugs and applicability, but the common feature is the small average particle size. Among the carriers with the potential nanostructured drug delivery application there are SLN and NLC. These nanostructured systems consist of complex lipids and highly purified mixtures of glycerides having varying particle size. Also, these systems have shown physical stability, protection capacity of unstable drugs, release control ability, excellent tolerability, possibility of vectorization, and no reported production problems related to large-scale. Several production procedures can be applied to achieve high association efficiency between the bioactive and the carrier, depending on the physicochemical properties of both, as well as on the production procedure applied. The whole set of unique advantages such as enhanced drug loading capacity, prevention of drug expulsion, leads to more flexibility for modulation of drug release and makes Lipid-based nanocarriers (LNCs) versatile delivery system for various routes of administration. The route of administration has a significant impact on the therapeutic outcome of a drug. Thus, the non-invasive routes, which were of minor importance as parts of drug delivery in the past, have assumed added importance drugs, proteins, peptides and biopharmaceuticals drug delivery and these include nasal, buccal, vaginal and transdermal routes. The objective of this paper is to present the state of the art concerning the application of the lipid nanocarriers designated for non-invasive routes of administration. In this manner, this review presents an innovative technological platform to develop nanostructured delivery systems with great versatility of application in non-invasive routes of administration and targeting drug release.

Multifunctional Nanocarriers for Lung Drug Delivery

Nanocarriers have been increasingly proposed for lung drug delivery applications. The strategy of combining the intrinsic and more general advantages of the nanostructures with specificities that improve the therapeutic outcomes of particular clinical situations is frequent. These include the surface engineering of the carriers by means of altering the material structure (i.e., chemical modifications), the addition of specific ligands so that predefined targets are reached, or even the tuning of the carrier properties to respond to specific stimuli. The devised strategies are mainly directed at three distinct areas of lung drug delivery, encompassing the delivery of proteins and protein-based materials, either for local or systemic application, the delivery of antibiotics, and the delivery of anticancer drugs-the latter two comprising local delivery approaches. This review addresses the applications of nanocarriers aimed at lung drug delivery of active biological and pharmaceutical ingredients, focusing with particular interest on nanocarriers that exhibit multifunctional properties. A final section addresses the expectations regarding the future use of nanocarriers in the area.

Bioavailability Enhancement of Poorly Soluble Drugs: The Holy Grail in Pharma Industry

Background:

Bioavailability, one of the prime pharmacokinetic properties of a drug, is defined as the fraction of an administered dose of unchanged drug that reaches the systemic circulation and is used to describe the systemic availability of a drug. Bioavailability assessment is imperative in order to demonstrate whether the drug attains the desirable systemic exposure for effective therapy. In recent years, bioavailability has become the subject of importance in drug discovery and development studies.

Methods:

A systematic literature review in the field of bioavailability and the approaches towards its enhancement have been comprehensively done, purely focusing upon recent papers. The data mining was performed using databases like PubMed, Science Direct and general Google searches and the collected data was exhaustively studied and summarized in a generalized manner.

Results:

The main prospect of this review was to generate a comprehensive one-stop summary of the numerous available approaches and their pharmaceutical applications in improving the stability concerns, physicochemical and mechanical properties of the poorly water-soluble drugs which directly or indirectly augment their bioavailability.

Conclusion:

The use of novel methods, including but not limited to, nano-based formulations, bio-enhancers, solid dispersions, lipid-and polymer-based formulations which provide a wide range of applications not only increases the solubility and permeability of the poorly bioavailable drugs but also improves their stability, and targeting efficacy. Although, these methods have drastically changed the pharmaceutical industry demand for the newer potential methods with better outcomes in the field of pharmaceutical science to formulate various dosage forms with adequate systemic availability and improved patient compliance, further research is required.

Role of Lipid Coating in the Transport of Nanodroplets across the Pulmonary Surfactant Layer Revealed by Molecular Dynamics Simulations

Hydrophilic drugs can be delivered into lungs via nebulization for both local and systemic therapies. Once inhaled, ultrafine nanodroplets preferentially deposit in the alveolar region, where they first interact with the pulmonary surfactant (PS) layer, with nature of the interaction determining both efficiency of the pulmonary drug delivery and extent of the PS perturbation. Here, we demonstrate by molecular dynamics simulations the transport of nanodroplets across the PS layer being improved by lipid coating. In the absence of lipids, bare nanodroplets deposit at the PS layer to release drugs that can be directly translocated across the PS layer. The translocation is quicker under higher surface tensions but at the cost of opening pores that disrupt the ultrastructure of the PS layer. When the PS layer is compressed to lower surface tensions, the nanodroplet prompts collapse of the PS layer to induce severe PS perturbation. By coating the nanodroplet with lipids, the disturbance of the nanodroplet on the PS layer can be reduced. Moreover, the lipid-coated nanodroplet can be readily wrapped by the PS layer to form vesicular structures, which are expected to fuse with the cell membrane to release drugs into secondary organs. Properties of drug bioavailability, controlled drug release, and enzymatic tolerance in real systems could be improved by lipid coating on nanodroplets. Our results provide useful guidelines for the molecular design of nanodroplets as carriers for the pulmonary drug delivery.

Development of Novel Octanoyl Chitosan Nanoparticles for Improved Rifampicin Pulmonary Delivery: Optimization by Factorial Design

A novel hydrophobic chitosan derivative, octanoyl chitosan (OC) with improved organic solubility was synthesized, characterized, and employed for the preparation of rifampicin (Rif) encapsulated nanoparticle formulations for pulmonary delivery. OC was characterized to confirm acyl group substitution and cytotoxicity in A549 epithelial lung cells. OC nanoparticles were produced by the double emulsion solvent evaporation technique without cross-linking and characterized for particle size distribution, morphology, crystallinity, thermal stability, aerosol delivery, and drug release rate. OC was successfully synthesized with substitution degree of 44.05 ± 1.75%, and solubility in a range of organic solvents. Preliminary cytotoxicity studies of OC showed no effect on cell viability over a period of 24 h on A549 cell lines. OC nanoparticles were optimized using a 3² full factorial design. An optimized batch of OC nanoparticles, smooth and spherical in morphology, had mean hydrodynamic diameter of 253 ± 19.06 nm (PDI 0.323 ± 0.059) and entrapment efficiency of 64.86 ± 7.73% for rifampicin. Pulmonary deposition studies in a two-stage impinger following aerosolization of nanoparticles from a jet nebulizer gave a fine particle fraction of 43.27 ± 4.24%. In vitro release studies indicated sustained release (73.14 ± 3.17%) of rifampicin from OC nanoparticles over 72 h, with particles demonstrating physical stability over 2 months. In summary, the results confirmed the suitability of the developed systems for pulmonary delivery of drugs with excellent aerosolization properties and sustained-release characteristics.

A comparison of the lung clearance kinetics of solid lipid nanoparticles and liposomes by following the 3H-labelled structural lipids after pulmonary delivery in rats

The utility of biodegradable nanosized drug carriers for the local and controlled delivery of therapeutics to the lungs has prompted significant interest in the development of inhalable nanomedicines. Still, little is known about how these systems are cleared from the lungs, including the kinetics of the structural lipids. Most preclinical and clinical studies to date have evaluated the lung clearance of loaded drugs, which in many cases poorly reflects the kinetics of the nanocarrier, or the bulk-labelled particles. This study therefore aimed to describe and compare the pulmonary pharmacokinetic behaviour and patterns of lung clearance of two commonly explored inhalable nanocarriers (anionic ∼150 nm liposomes and solid lipid nanoparticles [SLNs]) in rats by following the ³H-labelled structural lipids (phosphatidylcholine and tristearin respectively). The data showed that SLNs and liposomes were cleared from the lungs at similar rates, despite SLNs being deposited after intratracheal instillation in the upper respiratory track, and primarily via the mucociliary escalator, but this process was more pronounced for SLNs. Structural lipids were mainly associated with plasma proteins rather than nanocarrier in plasma. The lipids also exhibit prolonged lung exposure and are associated with the lung tissue (rather than BALF) over 2 weeks.