Pulmonary delivered polymeric micelles--pharmacokinetic evaluation and biodistribution studies

Polymeric Nanosystems: A Breakthrough Approach to Treating Inflammation and Inflammation Related Diseases

Inflammation processes can cause mild to severe damage in the human body and can lead to a large number of inflammation-related diseases (IRD) such as cancer, neural, vascular, and pulmonary diseases. Limitations of anti-inflammatory drugs (AID) application are reflected in high therapeutic doses, toxicity, low bioavailability and solubility, side effects, etc. Polymeric nanosystems (PS) have been recognized as a safe and effective technology that is able to overcome these limitations by AID encapsulation and is able to answer to the specific demands of the IRD treatment. PS are attracting great attention due to their versatility, biocompatibility, low toxicity, fine-tuned properties, functionality, and ability for precise delivery of anti-inflammatory drugs to the targeted sites in the human body. This article offers an overview of three classes of polymeric nanosystems: a) dendrimers, b) polymeric micelles and polymeric nanoparticles, and c) polymeric filomicelles, as well as their properties, preparation, and application in IRD treatment. In the future, the number of PS formulations in clinical practice will certainly increase.

Nanomedicines for Pulmonary Drug Delivery: Overcoming Barriers in the Treatment of Respiratory Infections and Lung Cancer

The pulmonary route for drug administration has garnered a great deal of attention in therapeutics for treating respiratory disorders. It allows for the delivery of drugs directly to the lungs and, consequently, the maintenance of high concentrations at the action site and a reduction in systemic adverse effects compared to other routes, such as oral or intravenous. Nevertheless, the pulmonary administration of drugs is challenging, as the respiratory system tries to eliminate inhaled particles, being the main responsible mucociliary escalator. Nanomedicines represent a primary strategy to overcome the limitations of this route as they can be engineered to prolong pulmonary retention and avoid their clearance while reducing drug systemic distribution and, consequently, systemic adverse effects. This review analyses the use of pulmonary-administered nanomedicines to treat infectious diseases affecting the respiratory system and lung carcinoma, two pathologies that represent major health threats.

Pulmonary arterial hypertension nanotherapeutics: New pharmacological targets and drug delivery strategies

Pulmonary arterial hypertension (PAH) is a rare, serious, and incurable disease characterized by high lung pressure. PAH-approved drugs based on conventional pathways are still not exhibiting favorable therapeutic outcomes. Drawbacks like short half-lives, toxicity, and teratogenicity hamper effectiveness, clinical conventionality, and long-term safety. Hence, approaches like repurposing drugs targeting various and new pharmacological cascades and/or loaded in non-toxic/efficient nanocarrier systems are being investigated lately. This review summarizes the status of conventional, repurposed, either in vitro, in vivo, and/or in clinical trials of PAH treatment. In-depth description, discussion, and classification of the new pharmacological targets and nanomedicine strategies with a description of all the nanocarriers that showed promising efficiency in delivering drugs are discussed. Ultimately, an illustration of the different nucleic acids tailored and nanoencapsulated within different types of nanocarriers to restore the pathways affected by this disease is presented.

Repositioned Natural Compounds and Nanoformulations: A Promising Combination to Counteract Cell Damage and Inflammation in Respiratory Viral Infections

Respiratory viral diseases are among the most important causes of disability, morbidity, and death worldwide. Due to the limited efficacy or side effects of many current therapies and the increase in antiviral-resistant viral strains, the need to find new compounds to counteract these infections is growing. Since the development of new drugs is a time-consuming and expensive process, numerous studies have focused on the reuse of commercially available compounds, such as natural molecules with therapeutic properties. This phenomenon is generally called drug repurposing or repositioning and represents a valid emerging strategy in the drug discovery field. Unfortunately, the use of natural compounds in therapy has some limitations, due to their poor kinetic performance and consequently reduced therapeutic effect. The advent of nanotechnology in biomedicine has allowed this limitation to be overcome, showing that natural compounds in nanoform may represent a promising strategy against respiratory viral infections. In this narrative review, the beneficial effects of some promising natural molecules, curcumin, resveratrol, quercetin, and vitamin C, which have been already studied both in native form and in nanoform, against respiratory viral infections are presented and discussed. The review focuses on the ability of these natural compounds, analyzed in in vitro and in vivo studies, to counteract inflammation and cellular damage induced by viral infection and provide scientific evidence of the benefits of nanoformulations in increasing the therapeutic potential of these molecules.

The in vivo fate of polymeric micelles

This review aims to provide a systemic analysis of the in vivo, as well as subcellular, fate of polymeric micelles (PMs), starting from the entry of PMs into the body. Few PMs are able to cross the biological barriers intact and reach the circulation. In the blood, PMs demonstrate fairly good stability mainly owing to formation of protein corona despite controversial results reported by different groups. Although the exterior hydrophilic shells render PMs "long-circulating", the biodistribution of PMs into the mononuclear phagocyte systems (MPS) is dominant as compared with non-MPS organs and tissues. Evidence emerges to support that the copolymer poly(ethylene glycol)-poly(lactic acid) (PEG-PLA) is first broken down into pieces of PEG and PLA and then remnants to be eliminated from the body finally. At the cellular level, PMs tend to be internalized via endocytosis due to their particulate nature and disassembled and degraded within the cell. Recent findings on the effect of particle size, surface characteristics and shape are also reviewed. It is envisaged that unraveling the in vivo and subcellular fate sheds light on the performing mechanisms and gears up the clinical translation of PMs.

An Update on Advancements and Challenges in Inhalational Drug Delivery for Pulmonary Arterial Hypertension

A lethal condition at the arterial–alveolar juncture caused the exhaustive remodeling of pulmonary arterioles and persistent vasoconstriction, followed by a cumulative augmentation of resistance at the pulmonary vascular and, consequently, right-heart collapse. The selective dilation of the pulmonary endothelium and remodeled vasculature can be achieved by using targeted drug delivery in PAH. Although 12 therapeutics were approved by the FDA for PAH, because of traditional non-specific targeting, they suffered from inconsistent drug release. Despite available inhalation delivery platforms, drug particle deposition into the microenvironment of the pulmonary vasculature and the consequent efficacy of molecules are influenced by pathophysiological conditions, the characteristics of aerosolized mist, and formulations. Uncertainty exists in peripheral hemodynamics outside the pulmonary vasculature and extra-pulmonary side effects, which may be further exacerbated by underlying disease states. The speedy improvement of arterial pressure is possible via the inhalation route because it has direct access to pulmonary arterioles. Additionally, closed particle deposition and accumulation in diseased tissues benefit the restoration of remolded arterioles by reducing fallacious drug deposition in other organs. This review is designed to decipher the pathological changes that should be taken into account when targeting the underlying pulmonary endothelial vasculature, especially with regard to inhaled particle deposition in the alveolar vasculature and characteristic formulations.

Nanostructures for drug delivery in respiratory diseases therapeutics: Revision of current trends and its comparative analysis

Respiratory diseases are leading causes of death and disability in developing and developed countries. The burden of acute and chronic respiratory diseases has been rising throughout the world and represents a major problem in the public health system. Acute respiratory diseases include pneumonia, influenza, SARS-CoV-2 and MERS viral infections; while chronic obstructive pulmonary disease (COPD), asthma and, occupational lung diseases (asbestosis, pneumoconiosis) and other parenchymal lung diseases namely lung cancer and tuberculosis are examples of chronic respiratory diseases. Importantly, chronic respiratory diseases are not curable and treatments for acute pathologies are particularly challenging. For that reason, the integration of nanotechnology to existing drugs or for the development of new treatments potentially benefits the therapeutic goals by making drugs more effective and exhibit fewer undesirable side effects to treat these conditions. Moreover, the integration of different nanostructures enables improvement of drug bioavailability, transport and delivery compared to stand-alone drugs in traditional respiratory therapy. Notably, there has been great progress in translating nanotechnology-based cancer therapies and diagnostics into the clinic; however, researchers in recent years have focused on the application of nanostructures in other relevant pulmonary diseases as revealed in our database search. Furthermore, polymeric nanoparticles and micelles are the most studied nanostructures in a wide range of diseases; however, liposomal nanostructures are recognized to be some of the most successful commercial drug delivery systems. In conclusion, this review presents an overview of the recent and relevant research in drug delivery systems for the treatment of different pulmonary diseases and outlines the trends, limitations, importance and application of nanomedicine technology in treatment and diagnosis and future work in this field.

Expanding the arsenal against pulmonary diseases using surface-functionalized polymeric micelles: breakthroughs and bottlenecks

Pulmonary diseases such as lung cancer, asthma and tuberculosis have remained one of the common challenges globally. Polymeric micelles (PMs) have emerged as an effective technique for achieving targeted drug delivery for a local as well as a systemic effect. These PMs encapsulate and protect hydrophobic drugs, increase pulmonary targeting, decrease side effects and enhance drug efficacy through the inhalation route. In the current review, emphasis has been placed on the different barriers encountered by the drugs given via the pulmonary route and the mechanism of PMs in achieving drug targeting. The applications of PMs in different pulmonary diseases have also been discussed in detail.

New Promising Therapeutic Avenues of Curcumin in Brain Diseases

Curcumin, the dietary polyphenol isolated from Curcuma longa (turmeric), is commonly used as an herb and spice worldwide. Because of its bio-pharmacological effects curcumin is also called "spice of life", in fact it is recognized that curcumin possesses important proprieties such as anti-oxidant, anti-inflammatory, anti-microbial, antiproliferative, anti-tumoral, and anti-aging. Neurodegenerative diseases such as Alzheimer's Diseases, Parkinson's Diseases, and Multiple Sclerosis are a group of diseases characterized by a progressive loss of brain structure and function due to neuronal death; at present there is no effective treatment to cure these diseases. The protective effect of curcumin against some neurodegenerative diseases has been proven by in vivo and in vitro studies. The current review highlights the latest findings on the neuroprotective effects of curcumin, its bioavailability, its mechanism of action and its possible application for the prevention or treatment of neurodegenerative disorders.

Nano-Derived Therapeutic Formulations with Curcumin in Inflammation-Related Diseases

Due to its vast therapeutic potential, the plant-derived polyphenol curcumin is utilized in an ever-growing number of health-related applications. Here, we report the extraction methodologies, therapeutic properties, advantages and disadvantages linked to curcumin employment, and the new strategies addressed to improve its effectiveness by employing advanced nanocarriers. The emerging nanotechnology applications used to enhance CUR bioavailability and its targeted delivery in specific pathological conditions are collected and discussed. In particular, new aspects concerning the main strategic nanocarriers employed for treating inflammation and oxidative stress-related diseases are reported and discussed, with specific emphasis on those topically employed in conditions such as wounds, arthritis, or psoriasis and others used in pathologies such as bowel (colitis), neurodegenerative (Alzheimer's or dementia), cardiovascular (atherosclerosis), and lung (asthma and chronic obstructive pulmonary disease) diseases. A brief overview of the relevant clinical trials is also included. We believe the review can provide the readers with an overview of the nanostrategies currently employed to improve CUR therapeutic applications in the highlighted pathological conditions.

Nano-Strategies for Improving the Bioavailability of Inhaled Pharmaceutical Formulations

Pulmonary pharmaceutical formulations are targeted for the treatment of respiratory diseases. However, their application is limited due to the physiological characteristics of the lungs, such as branching structure, mucociliary and macrophages, as well as certain properties of the drugs like particle size and solubility. Nano-formulations can ameliorate particle sizes and improve drug solubility to enhance bioavailability in the lungs. The nano-formulations for lungs reviewed in this article can be classified into nanocarriers, no-carrier-added nanosuspensions and polymer-drug conjugates. Compared with conventional inhalation preparations, these novel pulmonary pharmaceutical formulations have their own advantages, such as increasing drug solubility for better absorption and less inflammatory reaction caused by the aggregation of insoluble drugs; prolonging pulmonary retention time and reducing drug clearance; improving the patient compliance by avoiding multiple repeated administrations. This review will provide the reader with some background information for pulmonary drug delivery and give an overview of the existing literature about nano-formulations for pulmonary application to explore nano-strategies for improving the bioavailability of pulmonary pharmaceutical formulations.

Progress in the Application of Nano- and Micro-based Drug Delivery Systems in Pulmonary Drug Delivery

Nanotechnology is associated with the development of particles in the nano-size range that can be used in a wide range of applications in the medical field. It has gained more importance in the pharmaceutical research field particularly in drug delivery, as it results in enhanced therapeutic drug performance, improved drug solubility, targeted drug delivery to the specific sites, minimized side effects, and prolonged drug retention time in the targeted site. To date, the application of nanotechnology continues to offer several benefits in the treatment of various chronic diseases and results in remarkable improvements in treatment outcomes. The use of nano-based delivery systems such as liposomes, micelles, and nanoparticles in pulmonary drug delivery have shown to be a promising strategy in achieving drug deposition and maintained controlled drug release in the lungs. They have been widely used to minimize the risks of drug toxicity in vivo. In this review, recent advances in the application of nano- and micro-based delivery systems in pulmonary drug delivery for the treatment of various pulmonary diseases, such as lung cancer, asthma, and chronic obstructive pulmonary disease, are highlighted. Limitations in the application of these drug delivery systems and some key strategies in improving their formulation properties to overcome challenges encountered in drug delivery are also discussed.

Increased cross-linking micelle retention in the brain of Alzheimer's disease mice by elevated asparagine endopeptidase protease responsive aggregation

Current forms of medication for Alzheimer's disease (AD) provide a symptomatic benefit limited to those with early onset, but there is no single drug available for later stage patients. Given the recent failures of AD drugs in clinical trials, an intensive treatment strategy based on drug combination that is approved is attractive. At present, the greatest difficulty lies in the low accumulation of drugs in the brain. All hydrophilic drugs are limited by the physical and biochemical barriers within the blood-brain barrier and lipophilic drugs are often transported back into the blood by efflux pumps located in the blood-brain barrier. Here, we select elevated asparagine endopeptidase (AEP) as a target to trigger in situ cross-linking of small sized particles to form large sized drug clusters to block the efflux of the brain. Subsequently, responsive cross-linking micelles (RCMs) loaded with the acetylcholinesterase inhibitor, donepezil (DON), the microtubule therapeutic agent, Paclitaxel (PTX), and the glucose metabolism disorder regulator, insulin (INS) are investigated, with a focus on high levels of drug accumulation in the brain in AD. These smart multi-drug delivery RCMs provide a powerful system for AD treatment and can be adapted for other central nervous system (CNS) disorders.

Improvement of the pharmacokinetic/pharmacodynamic relationship in the treatment of invasive aspergillosis with voriconazole. Reduced drug toxicity through novel rapid release formulations

Voriconazole (VCZ) is currently the first-line treatment for invasive aspergillosis, although the doses are limited by its poor solubility and high hepatic toxicity. The aim of this study was to develop a solid self-dispersing micellar system of VCZ to improve the pharmacokinetic/pharmacodynamic (PK/PD) relationship and reduce hepatotoxicity. In this work, solid micellar systems of VCZ are formulated with different polysorbate 80 ratios using mannitol as a hydrophilic carrier. The novel micellar systems were characterized by scanning electron microscopy (SEM), powder X-ray diffraction (PXRD), differential scanning calorimetry (DSC) and dissolution studies. Self-dispersing micellar systems reduced VCZ crystallinity, leading to an improvement in its dissolution rate. The in vitro susceptibility test also revealed that the most common microorganisms in invasive aspergillosis exhibited low minimum inhibitory concentration (MIC) values for micellar systems. Pharmacokinetic studies indicated an improvement in bioavailability for MS-1:3:0.05, and changes in its biodistribution to different organs. MS-1:3:0.05 showed an increased concentration in lungs and a significant decrease in VCZ accumulated in the liver.

Drug Delivery with Polymeric Nanocarriers-Cellular Uptake Mechanisms

Nanocarrier-based systems hold a promise to become "Dr. Ehrlich's Magic Bullet" capable of delivering drugs, proteins and genetic materials intact to a specific location in an organism down to subcellular level. The key question, however, how a nanocarrier is internalized by cells and how its intracellular trafficking and the fate in the cell can be controlled remains yet to be answered. In this review we survey drug delivery systems based on various polymeric nanocarriers, their uptake mechanisms, as well as the experimental techniques and common pathway inhibitors applied for internalization studies. While energy-dependent endocytosis is observed as the main uptake pathway, the integrity of a drug-loaded nanocarrier upon its internalization appears to be a seldomly addressed problem that can drastically affect the uptake kinetics and toxicity of the system in vitro and in vivo.

Novel drug delivery systems and significance in respiratory diseases

Pulmonary drug delivery offers targeted therapy for the treatment of respiratory diseases such as asthma, lung cancer, and chronic obstructive pulmonary diseases. However, this route poses challenges like deposition mechanism, drug instability, and rapid clearance mechanism. Other factors like the type of inhaler device, patient compatibility, consistent delivery by device, and inhaler technique also affect the performance of pulmonary delivery systems. Thus, to overcome these issues, pulmonary delivery systems utilizing particle-based approaches (nano/microparticles) have emerged in the last two decades. This chapter provides insight into various mechanisms of pulmonary drug administration, the ideal requirements of a pulmonary system, and the general devices used for pulmonary delivery. An overview of new pulmonary delivery systems and their relevance in the treatment of respiratory diseases is provided. In the end, novel pulmonary technologies that have been patented and cleared clinical trials have been highlighted along with the advances in the inhaler device.

Puerarin-loaded PEG-PE micelles with enhanced anti-apoptotic effect and better pharmacokinetic profile

Puerarin (PUE) is the most abundant isoflavonoid in kudzu root. It is widely used as a therapeutic agent for the treatment of cardiovascular diseases. However, the short elimination half-life, poor-bioavailability, and acute intravascular hemolysis of PUE are the main obstacles to its widespread clinical applications. Whereas PEG-PE micelles possess the ability to release medicine slowly, enhance the cellular uptake of drugs and improve their biocompatibility. Therefore, it was aim to fabricate puerarin-loaded PEG-PE (PUE@PEG-PE) micelles to improve the pharmaceutical properties of drugs. It can be observed from the TEM images that PUE@PEG-PE micelles appeared obvious core-shell structure and remained well-dispersed without aggregation and adhesion. PUE was successfully embedded in the core of PEG-PE micelles, which was confirmed by FT-IR and ¹H NMR spectra. In vitro studies showed that PUE@PEG-PE micelles exhibited a sustained release behavior in pH 7.4 PBS buffer and decreased hemolysis rate of PUE. Compared with PUE, PUE@PEG-PE micelles showed a 3.2-fold increase in the half-life of PUE and a 1.58-fold increase in bioavailability. In addition, the PUE@PEG-PE micelles exerted enhanced protective effect against isoprenaline-induced H9c2 cells apoptosis compared with PUE, as evident by decreased percentage of Hoechst-positive cells, Caspase 3 activity, Bax expression, and increased Bcl-2 expression. Notably, the PEG-PE micelles exhibited favorable cellular uptake efficiency on H9c2 cells, and this may account for their enhanced anti-apoptotic effect of the incorporated drug. Altogether, the PUE@PEG-PE micelles were not only able to control the drug release but also offered promise to enhance the pharmacokinetic and pharmacodynamic potential of PUE.

Protoporphyrin IX-modified chitosan-g-oligo(NiPAAm) polymeric micelles: from physical stabilization to permeability characterization in vitro

Two main hurdles persist towards the more extensive bench-to-bed side translation of non-parenteral polymeric micelles. The first pertains to their thermodynamically-driven disassembly under uncontrolled dilution conditions in the biological milieu and upon interaction with biomacromolecules (e.g., proteins). The second is related to the relatively poor understanding of the pathways by which polymeric micelles improve the bioavailability of the payload by mucosal routes (e.g., intestinal). In this work, a chitosan-g-oligo(N-isopropylacrylamide) (CS-g-oligo(NiPAAm)) copolymer was modified with non-cytotoxic amounts of protoporphyrin IX (PP), a planar molecule of amphiphilic character that undergoes self-aggregation in water by forming π-π stacked supramolecular structures, to induce micellization under disfavored conditions and to serve as a fluorescent tracer for the measurement of the micelle permeability across a model of the intestinal epithelium in vitro. Findings indicated that the conjugation of PP amounts as low as 2% w/w induced the formation of micelles at temperatures below the lower critical solution temperature of oligo(NiPAAm) (30-32 °C). Moreover, permeability studies conducted at both 4 °C and 37 °C strongly suggested that despite the relatively large size of the micelles (200-300 nm), they cross the epithelial monolayer mainly by a paracellular pathway due to the opening of tight junctions. Complementary uptake studies by flow cytometry indicated that no endocytosis, though due to passive or facilitated diffusion, some internalization takes place.

High drug payload curcumin nanosuspensions stabilized by mPEG-DSPE and SPC: in vitro and in vivo evaluation

CONTEXT

Curcumin (CUR) is a promising drug candidate based on its broad bioactivities and good antitumor effect, but the application of CUR is potentially restricted because of its poor solubility and bioavailability.

OBJECTIVE

This study aims at developing a simple and effective drug delivery system for CUR to enhance its solubility and bioavailability thus to improve its antitumor efficacy.

MATERIALS AND METHODS

Curcumin nanosuspensions (CUR-NSps) were prepared by precipitation-ultrasonication method using mPEG2000-DSPE and soybean lecithin as a combined stabilizer.

RESULTS

CUR-NSps with a high drug payload of 67.07% were successfully prepared. The resultant CUR-NSps had a mean particle size of 186.33 ± 2.73 nm with a zeta potential of -19.00 ± 1.31 mV. In vitro cytotoxicity assay showed that CUR-NSps exhibited enhanced cytotoxicity compared to CUR solution. The pharmacokinetics results demonstrated that CUR-NSps exhibited a significantly greater AUC0-24 and prolonged MRT compared to CUR injections after intravenous administration. In the biodistribution study, CUR-NSps demonstrated enhanced biodistribution compared with CUR injections in liver, spleen, kidney, brain, and tumor. The CUR-NSps also showed improved antitumor therapeutic efficacy over the injections (70.34% versus 40.03%, p < 0.01).

CONCLUSIONS

These results suggest that CUR-NSps might represent a promising drug formulation for intravenous administration of CUR for the treatment of cancer.

Naringenin-loaded solid lipid nanoparticles: preparation, controlled delivery, cellular uptake, and pulmonary pharmacokinetics

Naringenin (NRG), a flavonoid compound, had been reported to exhibit extensive pharmacological effects, but its water solubility and oral bioavailability are only~46±6 µg/mL and 5.8%, respectively. The purpose of this study is to design and develop NRG-loaded solid lipid nanoparticles (NRG-SLNs) to provide prolonged and sustained drug release, with improved stability, involving nontoxic nanocarriers, and increase the bioavailability by means of pulmonary administration. Initially, a group contribution method was used to screen the best solid lipid matrix for the preparation of SLNs. NRG-SLNs were prepared by an emulsification and low-temperature solidification method and optimized using an orthogonal experiment approach. The morphology was examined by transmission electron microscopy, and the particle size and zeta potential were determined by photon correlation spectroscopy. The total drug content of NRG-SLNs was measured by high-performance liquid chromatography, and the encapsulation efficiency (EE) was determined by Sephadex gel-50 chromatography and high-performance liquid chromatography. The in vitro NRG release studies were carried out using a dialysis bag. The best cryoprotectant to prepare NRG-SLN lyophilized powder for future structural characterization was selected using differential scanning calorimetry, powder X-ray diffraction, and Fourier transform infrared spectroscopy. The short-term stability, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide (MTT) assay, cellular uptake, and pharmacokinetics in rats were studied after pulmonary administration of NRG-SLN lyophilized powder. Glycerol monostearate was selected to prepare SLNs, and the optimal formulation of NRG-SLNs was spherical in shape, with a particle size of 98 nm, a polydispersity index of 0.258, a zeta potential of −31.4 mV, a total drug content of 9.76 mg, an EE of 79.11%, and a cumulative drug release of 80% in 48 hours with a sustained profile. In addition, 5% mannitol (w/v) was screened as a cryoprotectant. Fourier transform infrared spectroscopy, differential scanning calorimetry, and powder X-ray diffraction studies confirmed that the drug was encapsulated into SLNs in an amorphous form. The lyophilized powder was stable at both refrigeration (4°C) and ambient temperature (25°C) for 3 months, and the MTT assay demonstrated that the SLNs were nontoxic. The cellular uptake of fluorescein isothiocyanate-labeled SLNs in A549 cells was highly time dependent over a period of 3 hours, while the pharmacokinetic study in Sprague Dawley rats showed that the relative bioavailability of NRG-SLNs was 2.53-fold greater than that of NRG suspension after pulmonary administration. This study shows that SLNs offer a promising pulmonary delivery system to increase the bioavailability of the poorly water-soluble drug NRG.

Mucoadhesive nanogels by ionotropic crosslinking of chitosan-g-oligo(NiPAam) polymeric micelles as novel drug nanocarriers

AIM

To investigate a novel kind of mucoadhesive nanogel based on the supramolecular aggregation of chitosan-g-oligo(N-isopropylacrylamide) copolymers.

MATERIALS & METHODS

Copolymers were synthesized by the graft-free radical polymerization of N-isopropylacrylamide on chitosan. The aggregation was studied by dynamic light scattering and nanoparticle tracking analysis (NTA), the nanostructure by transmission electron microscopy(TEM)/cryo-TEM, the mucoadhesiveness in vitro with mucin and the cytocompatibility in Caco2 cells.

RESULTS

Copolymers (36-74% w/w N-isopropylacrylamide content) showed critical micellar concentration between 2.0 and 40.0 × 10(-3)% w/v and micelles were nanometric and positively charged. Physical stabilization was achieved with ionotropic crosslinking. TEM/cryo-TEM revealed multimicellar aggregates with good mucoadhesion and cytocompatibility properties. Micellar systems (1-10% w/v) increased the solubility of efavirenz up to 1249-fold.

CONCLUSION

Results support the potential of these nano-drug delivery systems for improved mucosal administration of hydrophobic drugs.

Curcumin micelles improve mitochondrial function in neuronal PC12 cells and brains of NMRI mice - Impact on bioavailability

Curcumin, a polyphenolic compound abundant in the rhizome of Curcuma longa, has been reported to have various beneficial biological and pharmacological activities. Recent research revealed that curcumin might be valuable in the prevention and therapy of numerous disorders including neurodegenerative diseases like Alzheimer's disease. Due to its low absorption and quick elimination from the body, curcumin bioavailability is rather low which poses major problems for the use of curcumin as a therapeutic agent. There are several approaches to ameliorate curcumin bioavailability after oral administration, amongst them simultaneous administration with secondary plant compounds, micronization and micellation. We examined bioavailability in vivo in NMRI mice and the effects of native curcumin and a newly developed curcumin micelles formulation on mitochondrial function in vitro in PC12 cells and ex vivo in isolated mouse brain mitochondria. We found that curcumin micelles improved bioavailability of native curcumin around 10- to 40-fold in plasma and brain of mice. Incubation with native curcumin and curcumin micelles prevented isolated mouse brain mitochondria from swelling, indicating less mitochondrial permeability transition pore (mPTP) opening and prevention of injury. Curcumin micelles proved to be more efficient in preventing mitochondrial swelling in isolated mouse brain mitochondria and protecting PC12 cells from nitrosative stress than native curcumin. Due to their improved effectivity, curcumin micelles might be a suitable formulation for the prevention of mitochondrial dysfunction in brain aging and neurodegeneration.

A novel ligand conjugated nanoparticles for oral insulin delivery

In order to enhance the interaction between nanocarrier and gastrointestinal epithelial cells, we developed nanoparticles (NPs) modified with targeting ligand FQSIYPpIK (FQS), which specifically interact with integrin αvβ3 receptor expressing on the intestinal epithelium. The targeting NPs were prepared by coating the insulin-loaded poly(lactide-co-glycolide)-monomethoxy-poly(polyethylene glycol) micelle cores with FQS modified trimethyl chitosan chloride. In in vitro study, the fabricated NPs showed ameliorated drug release profile and improved enzymatic stability compared with micelles alone. In the integrin αvβ3 receptor over-expressed Caco-2 cells model, FQS modified NPs exhibited significantly accelerated intracellular uptake due to the active ligand-receptor mediation. Meanwhile, the targeting NPs also showed enhanced transport across the Caco-2 monolayer cells via both transcellular and paracellular pathways. Besides, orally administered FQS modified NPs produced a prominent hypoglycemic response and an increase of the serum insulin concentration in diabetic rats. Both in vitro and in vivo results demonstrated the FQS peptide modified NPs as promising intestinal cell-targeting nanocarriers for efficient oral delivery of insulin.

Nanoincorporation of curcumin in polymer-glycerosomes and evaluation of their in vitro–in vivo suitability as pulmonary delivery systems

This work was aimed at deliver curcumin to lungs by its incorporation into innovative vesicles glycerosomes and polymer-glycerosomes, the latter obtained combining glycerosomes with two polymers: sodium hyaluronate and trimethyl chitosan.