Development of Solid Lipid Nanoparticles for Controlled Amiodarone Delivery

In various drug delivery systems, solid lipid nanoparticles are dominantly lipid-based nanocarriers. Amiodarone hydrochloride is an antiarrhythmic agent used to treat severe rhythm disturbances. It has variable and hard-to-predict absorption in the gastrointestinal tract because of its low solubility and high permeability. The aims of this study were to improve its solubility by encapsulating amiodarone into solid lipid nanoparticles using two excipients-Compritol® 888 ATO (pellets) (C888) as a lipid matrix and Transcutol® (T) as a surfactant. Six types of amiodarone-loaded solid lipid nanoparticles (AMD-SLNs) were obtained using a hot homogenization technique followed by ultrasonication with varying sonication parameters. AMD-SLNs were characterized by their size distribution, polydispersity index, zeta potential, entrapment efficiency, and drug loading. Based on the initial evaluation of the entrapment efficiency, only three solid lipid nanoparticle formulations (P1, P3, and P5) were further tested. They were evaluated through scanning electron microscopy, Fourier-transform infrared spectrometry, near-infrared spectrometry, thermogravimetry, differential scanning calorimetry, and in vitro dissolution tests. The P5 formulation showed optimum pharmaco-technical properties, and it had the greatest potential to be used in oral pharmaceutical products for the controlled delivery of amiodarone.

Overview of Dual-Acting Drug Methotrexate in Different Neurological Diseases, Autoimmune Pathologies and Cancers

Methotrexate, a structural analogue of folic acid, is one of the most effective and extensively used drugs for treating many kinds of cancer or severe and resistant forms of autoimmune diseases. In this paper, we take an overview of the present state of knowledge with regards to complex mechanisms of methotrexate action and its applications as immunosuppressive drug or chemotherapeutic agent in oncological combination therapy. In addition, the issue of the potential benefits of methotrexate in the development of neurological disorders in Alzheimer’s disease or myasthenia gravis will be discussed.

Nobiletin-loaded micelles reduce ovariectomy-induced bone loss by suppressing osteoclastogenesis

Background

Nobiletin (NOB), a polymethoxy flavonoid, possesses anti-cancer and anti-inflammatory activities, has been reported that it played role in anti-osteoporosis treatment. However, previous research did not focus on practical use due to lack of hydrophilicity and cytotoxicity at high concentrations. The aim of this study was to develop a therapeutic formulation for osteoporosis based on the utilization of NOB.

Methods

In this study, NOB-loaded poly(ethylene glycol)-block-poly(e-caprolactone) (NOB-PEG-PCL) was prepared by dialysis method. The effects on osteoclasts and anti-osteoporosis functions were investigated in a RANKL-induced cell model and ovariectomized (OVX) mice.

Results

Dynamic light scattering and transmission electron microscopy examination results revealed that the NOB-PEG-PCL had a round shape, with a mean diameter around 124 nm. The encapsulation efficiency and drug loading were 76.34±3.25% and 7.60±0.48%, respectively. The in vitro release of NOB from NOB-PEG-PCL showed a remarkably sustained releasing characteristic and could be retained at least 48 hrs in pH 7.4 PBS. Anti-osteoclasts effects demonstrated that the NOB-PEG-PCL significantly inhibited the formation of tartrate-resistant acid phosphatase (TRAP)-positive multinuclear cells stimulated by RANKL. Furthermore, the NOB-PEG-PCL did not produce cytotoxicity on bone marrow-derived macrophages (BMMs). The mRNA expressions of genetic markers of osteoclasts including TRAP and cathepsin K were significantly decreased in the presence of NOB-PEG-PCL. In addition, the NOB-PEG-PCL inhibited OC differentiation of BMMs through RANKL-induced MAPK signal pathway. After administration of the NOB-PEG-PCL, NOB-PEG-PCL prevented bone loss and improved bone density in OVX mice. These findings suggest that NOB-PEG-PCL might have great potential in the treatment of osteoporosis.

Conclusion

The results suggested that NOB-PEG-PCL micelles could effectively prevent NOB fast release from micelles and extend circulation time. The NOB-PEG-PCL delivery system may be a promising way to prevent and treat osteoporosis.

Biomimetic and bioinspired nanoparticles for targeted drug delivery

In drug targeting, the urgent need for more effective and less iatrogenic therapies is pushing toward a complete revision of carrier setup. After the era of 'articles used as homing systems', novel prototypes are now emerging. Newly conceived carriers are endowed with better biocompatibility, biodistribution and targeting properties. The biomimetic approach bestows such improved functional properties. Exploiting biological molecules, organisms and cells, or taking inspiration from them, drug vector performances are now rapidly progressing toward the perfect carrier. Following this direction, researchers have refined carrier properties, achieving significant results. The present review summarizes recent advances in biomimetic and bioinspired drug vectors, derived from biologicals or obtained by processing synthetic materials with a biomimetic approach.

Effect of Neonatal Exposure to Poly(Ethylene Glycol)-block-Poly(Lactic Acid) Nanoparticles on Oxidative State in Infantile and Adult Female Rats

Our goal was to evaluate the potential health risk of the polymeric NP, poly(ethylene glycol)-block-poly(lactic acid) (PEG-b-PLA), from the view of redox imbalance of the organism in two different life stages. Female Wistar rats were neonatally administered intraperitoneally with PEG-b-PLA NPs [20 mg/kg of b.w. (PEG20) or 40 (PEG40) mg/kg of b.w.] from postnatal day 4 (PND4) to PND7. We measured antioxidant capacity (TEAC), level of protein carbonyls and lipoperoxides in plasma, activities of catalase, glutathione peroxidase (GPx), and superoxide dismutase (SOD) in hemolysates of infantile (sacrificed on PND17) and adult (sacrificed after PND176) rats. Compared to controls, neonatal PEG40 exposure induced a significant TEAC reduction in the infantile rats. Protein carbonyls and lipoperoxide levels were not affected after any dose of PEG-b-PLA NP administration. In adult rats, PEG20 administration caused a significant decrease of protein carbonyl levels compared to controls. In infantile rats, both doses of PEG-b-PLA NP administration increased catalase, Gpx, and SOD activities compared to controls. Surprisingly, in adult rats, the activities of Gpx and SOD decreased significantly after administration of both doses of PEG-b-PLA NPs. Obtained data indicate a possible age-related association between the oxidative status and neonatal PEG-b-PLA NP administration in female rats.

Novel biodegradable nanocarriers for enhanced drug delivery

With the refinement of functional properties, the interest around biodegradable materials, in biorelated applications and, in particular, in their use as controlled drug-delivery systems, increased in the last decades. Biodegradable materials are an ideal platform to obtain nanoparticles for spatiotemporal controlled drug delivery for the in vivo administration, thanks to their biocompatibility, functionalizability, the control exerted on delivery rates and the complete degradation. Their application in systems for cancer treatment, brain and cardiovascular diseases is already a consolidated practice in research, while the bench-to-bedside translation is still late. This review aims at summarizing reported applications of biodegradable materials to obtain drug-delivery nanoparticles in the last few years, giving a complete overview of pros and cons related to degradable nanomedicaments.

Alendronate-Loaded Modified Drug Delivery Lipid Particles Intended for Improved Oral and Topical Administration

The present paper focuses on solid lipid particles (SLPs), described in the literature as the most effective lipid drug delivery systems that have been introduced in the last decades, as they actually combine the advantages of polymeric particles, hydrophilic/lipophilic emulsions and liposomes. In the current study, we present our most recent advances in the preparation of alendronate (AL)-loaded SLPs prepared by hot homogenization and ultrasonication using various ratios of a self-emulsifying lipidic mixture of Compritol 888, Gelucire 44/14, and Cremophor A 25. The prepared AL-loaded SLPs were investigated for their physicochemical, morphological and structural characteristics by dynamic light scattering, differential scanning calorimetry, thermogravimetric and powder X-ray diffraction analysis, infrared spectroscopy, optical and scanning electron microscopy. Entrapment efficacy and actual drug content were assessed by a validated HPLC method. In vitro dissolution tests performed in simulated gastro-intestinal fluids and phosphate buffer solution pH 7.4 revealed a prolonged release of AL of 70 h. Additionally, release kinetics analysis showed that both in simulated gastrointestinal fluids and in phosphate buffer solution, AL is released from SLPs based on equal ratios of lipid excipients following zero-order kinetics, which characterizes prolonged-release drug systems.

Nano carriers for drug transport across the blood-brain barrier

Effective therapy lies in achieving a therapeutic amount of drug to the proper site in the body and then maintaining the desired drug concentration for a sufficient time interval to be clinically effective for treatment. The blood-brain barrier (BBB) hinders most drugs from entering the central nervous system (CNS) from the blood stream, leading to the difficulty of delivering drugs to the brain via the circulatory system for the treatment, diagnosis and prevention of brain diseases. Several brain drug delivery approaches have been developed, such as intracerebral and intracerebroventricular administration, intranasal delivery and blood-to-brain delivery, as a result of transient BBB disruption induced by biological, chemical or physical stimuli such as zonula occludens toxin, mannitol, magnetic heating and ultrasound, but these approaches showed disadvantages of being dangerous, high cost and unsuitability for most brain diseases and drugs. The strategy of vector-mediated blood-to-brain delivery, which involves improving BBB permeability of the drug-carrier conjugate, can minimize side effects, such as being submicrometre objects that behave as a whole unit in terms of their transport and properties, nanomaterials, are promising carrier vehicles for direct drug transport across the intact BBB as a result of their potential to enter the brain capillary endothelial cells by means of normal endocytosis and transcytosis due to their small size, as well as their possibility of being functionalized with multiple copies of the drug molecule of interest. This review provids a concise discussion of nano carriers for drug transport across the intact BBB, various forms of nanomaterials including inorganic/solid lipid/polymeric nanoparticles, nanoemulsions, quantum dots, nanogels, liposomes, micelles, dendrimers, polymersomes and exosomes are critically evaluated, their mechanisms for drug transport across the BBB are reviewed, and the future directions of this area are fully discussed.

Plant extracts: from encapsulation to application

INTRODUCTION

Plants are a natural source of various products with diverse biological activities offering treatment for several diseases. Plant extract is a complex mixture of compounds, which can have antioxidant, antibiotic, antiviral, anticancer, antiparasitic, antifungal, hypoglycemic, anti-hypertensive and insecticide properties. The extraction of these extracts requires the use of organic solvents, which not only complicates the formulations but also makes it difficult to directly use the extracts for humans. To overcome these problems, recent research has been focused on developing new ways to formulate the plant extracts and delivering them safely with enhanced therapeutic efficacy.

AREAS COVERED

This review focuses on the research done in the development and use of polymeric nanoparticles for the encapsulation and administration of plant extracts. It describes in detail, the different encapsulation techniques, main physicochemical characteristics of the nanoparticles, toxicity tests and results obtained from in vivo or in vitro assays.

EXPERT OPINION

Major obstacles associated with the use of plant extracts for clinical applications include their complex composition, toxicity risks and extract instability. It is observed that encapsulation can be successfully used to decrease plant extracts toxicity, to provide targeted drug delivery and to solve stability related problems.

Molecular determinants of blood-brain barrier permeation

The blood-brain barrier (BBB) is a microvascular unit which selectively regulates the permeability of drugs to the brain. With the rise in CNS drug targets and diseases, there is a need to be able to accurately predict a priori which compounds in a company database should be pursued for favorable properties. In this review, we will explore the different computational tools available today, as well as underpin these to the experimental methods used to determine BBB permeability. These include in vitro models and the in vivo models that yield the dataset we use to generate predictive models. Understanding of how these models were experimentally derived determines our accurate and predicted use for determining a balance between activity and BBB distribution.

Techniques in Electron Microscopy of Animal Tissue

Technical improvements in electron microscopy, both instrumental and preparative, permit increasingly accurate analyses. Digital images for transmission electron microscopy (TEM) can be processed by software programs that automate tasks and create custom tools that allow for image enhancement for brightness, contrast and coloration; for creation of rectangular, ellipsoidal or irregular area selections; and for measurement of mean area and standard deviation. Sample preparation remains a source of error since organelles and spatial arrangements of macromolecules rapidly change after anoxia. Guidelines for maintaining consistency in preparation, examination and interpretation are presented for different electron microscopy (EM) modalities.

Drug carriers in osteoporosis: preparation, drug encapsulation and applications

Carriers are largely used to enhance therapy efficiency via the encapsulation of active molecules. The encapsulation enhances the stability of drug molecules, improves the targeting properties and prolongs pharmacological activity via continuous local release of active molecules. The aim of this review is to report the carrier systems used in osteoporosis therapy. This state of the art research has mainly focused on describing all types of carriers used in this area, their elaboration and properties, the drug characteristics used in such specific application, and drug release and efficiency. In this field, various processes have been used in order to obtain well-defined capsules, spheres and more complex carriers. In this exhaustive review, each process is described, illustrated and discussed.