Therapeutic potential of nanoemulsions as feasible wagons for targeting Alzheimer's disease

Pterostilbene nanoemulsion promotes Nrf2 signaling pathway to downregulate oxidative stress for treating Alzheimer's disease

Pterostilbene, a stilbene compound, demonstrates neuroprotective effects through its antioxidant and anti-inflammatory properties. However, pterostilbene exhibits low bioavailability. We developed a pterostilbene nanoemulsion with better release stability and particle size. Behavioral tests, including the Y maze, new object recognition, and water maze, revealed that the pterostilbene nanoemulsion demonstrated a more significant effect on improving learning and memory function than pterostilbene. Immunofluorescence analysis revealed that pterostilbene nanoemulsion was more potent in safeguarding hippocampal neurons and inhibiting apoptosis and oxidative stress than pterostilbene. Further results from the Western blot and quantitative reverse transcription polymerase chain reaction indicated that the enhanced efficacy of pterostilbene nanoemulsion may be attributed to its stronger promotion of the nuclear factor erythroid 2-related factor 2 signaling pathway. Hence, enhanced drug delivery efficiency decreased dosage requirements and increased the bioavailability of pterostilbene, thereby potentially providing a safe, effective, and convenient treatment option for patients with Alzheimer's disease.

Receptor-Assisted Nanotherapeutics for Overcoming the Blood-Brain Barrier

Blood-brain barrier (BBB) is a distinguishing checkpoint that segregates peripheral organs from neural compartment. It protects the central nervous system from harmful ambush of antigens and pathogens. Owing to such explicit selectivity, the BBB hinders passage of various neuroprotective drug molecules that escalates into poor attainability of neuroprotective agents towards the brain. However, few molecules can surpass the BBB and gain access in the brain parenchyma by exploiting surface transporters and receptors. For successful development of brain-targeted therapy, understanding of BBB transporters and receptors is crucial. This review focuses on the transporter and receptor-based mechanistic pathway that can be manoeuvred for better comprehension of reciprocity of receptors and nanotechnological vehicle delivery. Nanotechnology has emerged as one of the expedient noninvasive approaches for brain targeting via manipulating the hurdle of the BBB. Various nanovehicles are being reported for brain-targeted delivery such as nanoparticles, nanocrystals, nanoemulsion, nanolipid carriers, liposomes and other nanovesicles. Nanotechnology-aided brain targeting can be a strategic approach to circumvent the BBB without altering the inherent nature of the BBB.

Simultaneous Intranasal Codelivery of Donepezil and Memantine in a Nanocolloidal Carrier: Optimization, Pharmacokinetics, and Pharmacodynamics Studies

This work focuses on developing nanoemulsions using a low-energy emulsification method for the codelivery of donepezil and memantine in one dosage form intended to be administered via the intranasal route for enhanced brain delivery. The nanoemulsion formulation was prepared using a low emulsification technique and characterized using various microscopy and nasal ciliotoxicity studies. The safe nanoemulsion was intended for preclinical pharmacokinetics with brain distribution and pharmacodynamics in a scopolamine-induced murine model. The formulated nanoemulsion was 16 nm in size, with a zeta potential of -7.22 mV, and exhibited a spherical shape. The brain concentration of IN-administered NE for DPZ and MEM was ∼678 and 249 ng/mL after 15 min. This concentration is more than 2 times higher in amount when compared with NE administered via PO, free drug solution administered via IN and PO route both. However, the plasma concentration of IN-administered NE for DPZ and MEM was ∼3 and 28 ng/mL after 15 min. In pharmacodynamic studies, the efficacy of NE administered via the IN route was higher when compared with other groups in neurobehavioral, biochemical estimation, and gene expression studies. The results suggest that the IN route can be explored in the future for the delivery of actives via nanocolloidal carriers in the brain for neurological disorders and can serve as promising alternatives for conventional dosage forms and routes.

Study of nanoemulsions using carvacrol/MCT-(Oleic acid-potassium oleate)/ Tween 80 ®- water system by low energy method

Carvacrol is studied in different fields due to its microbial and antioxidant properties. Its use is limited because of the water insolubility and its strong taste. To overcome these problems, carvacrol has been successfully loaded into nanoemulsions. The low-energy emulsification method Phase Inversion Composition (PIC) is used to prepare oil-in-water nanoemulsions in the carvacrol/medium chain triglycerides (MCT)-(oleic acid-potassium oleate/Tween 80 ®)-water system. Oleic acid acts as a co-surfactant when it is neutralized with KOH along the emulsification path changing the spontaneous curvature of the interface when increasing the HLB number from 1 for the oleic acid to 20 for the potassium oleate and, therefore, changing the HLB number of the surfactant mixture. The phases diagrams are studied in order to understand the behaviour of the system and to establish the composition range where nanoemulsions can be obtained. Nanoemulsions are formed when the emulsification path crosses a region of direct or planar structure without excess of oil. Experimental design is performed in order to study the influence of composition variables as carvacrol/MCT ratio and (oleic-oleate)/Tween 80 ® ratio (OL-OT/T80 ratio) on the diameter of the nanoemulsions and their stability. It has been observed the importance of the HLB number of the surfactants mixture in order to obtain small-sized stable nanoemulsions. Surface response graphic shows that (OL-OT)/T80 ratio is a significant parameter in the mean diameter of the nanoemulsions. A minimum diameter is obtained for a (OL-OT)/T80 ratio 45/55 due to the fact that ratio is near the preferred HLB of the oil mixture and the emulsification path contains a wide liquid crystal monophasic region with all the oil incorporated in the structure. Diameters of 19 nm for carvacrol/MCT ratio of 30/70 or diameters of 30 nm for ratios of 45/55 with high stability values presented a good potential to be incorporated into edible films in the future. Regarding nanoemulsions stability an optimum value is also observed for a carvacrol/MCT ratio. The addition of another carrier oil as olive oil instead of MCT showed an improvement of the nanoemulsions stability against Ostwald ripening, probably due to the smaller solubility of olive oil. The use of olive oil does not significantly change the diameter of the nanoemulsion.

Drug Discovery and Development Targeting Dementia

Dementia, most often associated with neurodegenerative diseases, affects millions of people worldwide, predominantly the elderly. Unfortunately, no treatment is still available. Therefore, there is an urgent need to address this situation. This review presents the state of the art of drug discovery and developments in targeting dementia. Several approaches are discussed, such as drug repurposing, the use of small molecules, and phosphodiesterase inhibitors. Furthermore, the review also provides insights into clinical trials of these molecules. Emphasis has been placed on small molecules and multi-target-directed ligands, as well as disease-modifying therapies. Finally, attention is drawn to the possibilities of applications of nanotechnology in managing dementia.

Nano and Microemulsions for the Treatment of Depressive and Anxiety Disorders: An Efficient Approach to Improve Solubility, Brain Bioavailability and Therapeutic Efficacy

Most drugs used for the treatment of depression, anxiety and related disorders have low absorption, high metabolism, low brain targeting and/or low water solubility, which can make it hard to formulate them at high strength and can also lead to decreased bioavailability. Incorporating these drugs into nanometric emulsions can solve these issues. Hence, the aim of the present review was to assess the potential of nano and micro emulsions for the delivery of antidepressant and anxiolytic drugs. The results from several studies showed that nanometric emulsions were able to increase drug strength up to 20,270-fold (compared to aqueous solubility). Moreover, in general, the formulations showed droplet size, polydispersity index, zeta potential, viscosity, osmolality, pH, in vitro drug release and ex vivo drug permeation as adequate for the intended effect and administration route. In vivo animal pharmacokinetic experiments showed that nanometric emulsions improved systemic drug bioavailability and/or brain targeting, and in vivo pharmacodynamic studies showed that they had antidepressant and/or anxiolytic effects, also being apparently safe. Hence, the current review provides proof of the potential of nano and microemulsions for improving solubilization and increasing the overall bioavailability of antidepressant and/or anxiolytic drugs, providing evidence of a possible useful strategy for future therapies.

PLGA-Based Nanomedicine: History of Advancement and Development in Clinical Applications of Multiple Diseases

Research on the use of biodegradable polymers for drug delivery has been ongoing since they were first used as bioresorbable surgical devices in the 1980s. For tissue engineering and drug delivery, biodegradable polymer poly-lactic-co-glycolic acid (PLGA) has shown enormous promise among all biomaterials. PLGA are a family of FDA-approved biodegradable polymers that are physically strong and highly biocompatible and have been extensively studied as delivery vehicles of drugs, proteins, and macromolecules such as DNA and RNA. PLGA has a wide range of erosion times and mechanical properties that can be modified. Many innovative platforms have been widely studied and created for the development of methods for the controlled delivery of PLGA. In this paper, the various manufacturing processes and characteristics that impact their breakdown and drug release are explored in depth. Besides different PLGA-based nanoparticles, preclinical and clinical applications for different diseases and the PLGA platform types and their scale-up issues will be discussed.

Recent nanoengineered diagnostic and therapeutic advancements in management of Sepsis

COVID-19 acquired symptoms have affected the worldwide population and increased the load of Intensive care unit (ICU) patient admissions. A large number of patients admitted to ICU end with a deadly fate of mortality. A high mortality rate of patients was reported with hospital-acquired septic shock that leads to multiple organ failures and ultimately ends with death. The patients who overcome this septic shock suffer from morbidity that also affects their caretakers. To overcome these situations, scientists are exploring progressive theragnostic techniques with advanced techniques based on biosensors, biomarkers, biozymes, vesicles, and others. These advanced techniques pave the novel way for early detection of sepsis-associated symptoms and timely treatment with appropriate antibiotics and immunomodulators and prevent the undue effect on other parts of the body. There are other techniques like externally modulated electric-based devices working on the principle of piezoelectric mechanism that not only sense the endotoxin levels but also target them with a loaded antibiotic to neutralize the onset of inflammatory response. Recently researchers have developed a lipopolysaccharide (LPS) neutralizing cartridge that not only senses the LPS but also appropriately neutralizes with dual mechanistic insights of antibiotic and anti-inflammatory effects. This review will highlight recent developments in the new nanotechnology-based approaches for the diagnosis and therapeutics of sepsis that is responsible for the high number of deaths of patients suffering from this critical disease.

Rosemary oil low energy nanoemulsion: optimization, µrheology, in silico, in vitro, and ex vivo characterization

Acetylcholine imbalance in the human brain causes dementia-related symptoms of Alzheimer's disease. Acetylcholinesterase (AChE) inhibitors prevent the lysis of acetylcholine in the brain and prevent dementia. Therefore, the present study aims to investigate the in silico and in vitro AChE potential of rosemary oil and then formulate it into nanoemulsion as an adjuvant with co-administration of Donepezil (Dz) with a thought for futuristic target for Alzheimer's diseases via the intranasal route. The aim for preparing this formulation was to add the AChE inhibition effect of the rosemary oil to the effect that acts as an additive effect along with Dz. The docking score of rosemary oil components on human cholinesterase 1GQR protein was found to be >-5 kcal/mol. In vitro AChE activity of rosemary oil confirms the prominent IC50 of oil at 0.001 µL/min. Nanoemulsion was prepared by low energy emulsification technique using Tween 80 as surfactant and ethanol or diethylene glycol monoethyl ether as cosurfactant. Droplet size, polydisperity index, and zeta potential of stable nanoemulsion was ∼16 nm, 0.1, and -6.05 mV for stable batch. High-resolution transmission electron microscopy microscopic studies depicted the spherical shape of the droplet. Micro rheology investigation of nanoemulsion clearly attributes to gel-sol-gel behaviour of formulated nanoemulsion. Thermal evaluation of nanoemulsion depicts the phase transition behaviour of ethanol-based nanoemulsion at 60 °C. Ex vivo nasal ciliotoxicity and permeation studies of formulation establish the safety of ethanol-based rosemary oil-loaded nanoemulsion and permeation mechanism of Dz from the nanoemulsion. In vitro permeation studies showed more drug penetration from the nanoemulsion as compared to the plain drug. The prepared nanoemulsion was found to be stable for 3 months at 4, 25, and 45 °C of storage. This low energy preparation method can be advantageous for the preparation of scalable nanoemulsion and can be a futuristic therapeutic for Alzheimer's disease.

Fabrication of TPGS-Grafted Polyamidoamine Dendrimer for Enhanced Piperine Brain Delivery and Pharmacokinetics

Piperine (PIP) is a neuroprotective phytomedicine that has profound acetylcholine esterase and reactive oxygen species inhibition effect in Alzheimer's disease (AD) model. However, the oral delivery of PIP is limited by poor aqueous solubility and low bioavailability in systemic circulation. To improve the PIP bioavailability, the polyamidoamine (PAMAM) G4 dendrimer is grafted with tocopheryl polyethylene glycol succinate-1000 (TPGS) through carbodiimide chemistry to form TPGS-PAMAM conjugate. The TPGS-PAMAM coupling was confirmed through proton NMR and FTIR techniques. PIP was encapsulated in the TPGS-PAMAM through solvent diffusion method to form PIP-TPGS-PAMAM. The particle size for PIP-TPGS-PAMAM found the less than 50 nm, whereas entrapment efficiency found to 87 ± 3.5% and 10.6 ± 2.9% drug loading. The powder differential scanning calorimetry and powder X-ray diffraction characterization were employed to evaluate the amorphous encapsulation of the PIP in TPGS-PAMAM. The PIP-TPGS-PAMAM stability was studied in the gastric fluids which showed no drastic difference in particle size and encapsulation efficiency compared to PIP-PAMAM. The in vitro release analysis revealed 37 ± 4.1% PIP release from the PIP-TPGS-PAMAM matrix, and 71 ± 4.9% PIP release from the PIP-PAMAM dendrimer was observed in 48 h. The single-dose oral gavage to Wistar rats of PIP-TPGS-PAMAM showed the AUC_0-∞ 14.38 µg/mL.h, C_max 7.77 ± 1.65 µg/mL, T_max, 1.6 ± 0.18 h, and half-life 3.47 ± 0.64 h for PIP in systemic circulation. PIP-PAMAM and free PIP showed significantly poor AUC_0-∞ compared to PIP-TPGS-PAMAM. The brain uptake studies revealed PIP-TPGS-PAMAM treated group showed 2.2 ± 0.37 µg/g PIP content compared to free PIP administered group which was 0.4 ± 0.10 µg/g. Therefore, PIP-TPGS-PAMAM can offer excellent prospect for the delivery hydrophobic drugs to brain in AD.

Upgrading the Transdermal Biomedical Capabilities of Thyme Essential Oil Nanoemulsions Using Amphiphilic Oligochitosan Vehicles

(1) Background: Thymus vulgaris L. (thyme) essential oil (TEO) has gained much attention because of its long history of medicinal usage. However, the lack of precise chemical profiling of the TEO and methods to optimize the bioactivity and delivery of its constituents has hampered its research on quality control and biological function; (2) Methods: The current study aimed to analyze the TEO’s chemical composition using the GC-MS method and identify its key components. Another objective of this work is to study the impact of the protective layer of amphiphilic oligochitosan (AOC) on the physicochemical stability and transdermal potentials of TEO multilayer nanoemulsions formulated by the incorporation of TEO, Tween80, lecithin (Lec), and AOC; (3) Results: The AOC protective layer significantly improved the stability of TEO-based NEs as revealed by the constancy of their physicochemical properties (particle size and zeta potential) during storage for a week. Excessive fine-tuning of thyme extract NEs and the AOC protective layer’s persistent positive charge have been contributed to the thyme extract’s improved anti-inflammatory, transdermal, and anti-melanoma potentials; (4) Conclusions: the AOC-coated NEs could offer novel multifunctional nanoplatforms for effective transdermal delivery of lipophilic bioactive materials.

Nanocarrier mediated drug delivery as an impeccable therapeutic approach against Alzheimer's disease

For the past several years, dementia, is one of the predominantly observed groups of symptoms in a geriatric population. Alzheimer's disease (AD) is a progressive memory related neurodegenerative disease, for which the current Food and drug administration approved therapeutics are only meant for a symptomatic management rather than targeting the root cause of AD. These therapeutics belong to two classes, Acetylcholine Esterase inhibitors and N-methyl D-aspartate antagonist. Furthermore, to facilitate neuroprotective action in AD, the drugs are majorly expected to reach the specific target area in the brain for the desired efficacy. Thus, there is a huge requirement for drug discovery and development for facilitating the entry of drugs more in brain to exert a specific action. The very first line of defense and the major limitation for the entry of drugs into the brain is the Blood Brain Barrier, followed by Blood-Cerebrospinal Fluid Barrier. More than a barrier, these mainly act as selectively permeable membranes, which allows entry of specific molecules into the brain. Furthermore, specific enzymes result in the degradation of xenobiotics. All these mechanisms pose as hurdles in the way of effective drug delivery in the brain. Thus, novel techniques need to be harbored for the facilitation of the delivery of such drugs into the brain. Nanocarriers are advantageous for facilitating the specific targeted drug treatment in AD. As nanomedicines are one of the novels and most useful approaches for AD, thus the present review mainly focuses on understanding the advanced use of nanocarriers for targeted drug delivery in the management of AD.

Therapeutic application of microsponges based drug delivery system

Microsponges delivery system (MDS) is highly porous, cross-linked based polymeric systems, that activates in the presence of temperature, rubbing and pH. MDS offers wide range of advantage, like controlled drug release, site-specific action, stable over a broad range of pH, poor irritation, cost effective, improved patient compliance. They can be transformed into various dosage forms like creams, gels, and lotions. MDS based system are suitable for treatment of topical disorders like acne, psoriasis, dandruff, eczema, scleroderma, hair loss, skin cancer, and other dreadful diseases. MDS application for drug delivery is not limited to topical drug delivery but also explored for oral, parenteral and pulmonary drug delivery. Microsponges were studied for colon targeting of drugs and genes. Additionally, MDS has wide application for sunscreen, cosmetics, and over the counter (OTC) products. Furthermore, MDS does not actuate any irritation, genotoxicity, immunogenicity or cytotoxicity. Therefore, this review extensively highlights about microsponges, their advantages, key factors affecting the micro-sponges' characteristics, the therapeutic application of microsponges in topical disorders, cancer, as cosmetics, recent advances in MDS and addresses the associated challenges.

Using the Intranasal Route to Administer Drugs to Treat Neurological and Psychiatric Illnesses: Rationale, Successes, and Future Needs

While the intranasal administration of drugs to the brain has been gaining both research attention and regulatory success over the past several years, key fundamental and translational challenges remain to fully leveraging the promise of this drug delivery pathway for improving the treatment of various neurological and psychiatric illnesses. In response, this review highlights the current state of understanding of the nose-to-brain drug delivery pathway and how both biological and clinical barriers to drug transport using the pathway can been addressed, as illustrated by demonstrations of how currently approved intranasal sprays leverage these pathways to enable the design of successful therapies. Moving forward, aiming to better exploit the understanding of this fundamental pathway, we also outline the development of nanoparticle systems that show improvement in delivering approved drugs to the brain and how engineered nanoparticle formulations could aid in breakthroughs in terms of delivering emerging drugs and therapeutics while avoiding systemic adverse effects.

Recent advances in lipid-engineered multifunctional nanophytomedicines for cancer targeting

Cancer is a leading cause of death in many countries around the world. However, the efficacy of current treatments available for variety of cancers is considered to be suboptimal due to the pathophysiological challenges associated with the disease which limits the efficacy of the anticancer drugs. Moreover, the vulnerability towards off-target effects and high toxicity also limits the use of drugs for the treatment of cancers. Besides, the biopharmaceutical challenges like poor water solubility and permeability of the drugs, along with the absence of active targeting capability further decreases the utility of drugs in cancer therapy. As a result of these deficiencies, the current therapeutic strategies face noncompliance to patients for providing meaningful benefits after administration. With the advancements in nanotechnology, there has been a paradigm shift in the modalities for cancer treatment with the help of phytomedicine-based nanosized drug delivery systems coupled with variegated surface-engineering strategies for targeted drug delivery. Among these delivery systems, lipid-based nanoparticles are considered as one of the highly biocompatible, efficient and effective systems extensively explored for anticancer drug delivery. These include diverse range of systems including liposomes, nanoemulsions, solid lipid nanoparticles, nanostructured lipidic carriers and supramolecular carriers, which alters pharmacokinetic and biodistribution of the drugs for active targeting to the desired site of action by overcoming the biopharmaceutical challenges associated with anticancer drug delivery. The present review endeavours to provide a comprehensive account on the recent advances in the application of lipid-based nanostructured systems for improving the pharmacotherapeutic performance of phytomedicines for cancer targeting application.