Pharmacological, toxicological and neuronal localization assessment of galantamine/chitosan complex nanoparticles in rats: future potential contribution in Alzheimer’s disease management

Exosomes and non-coding RNAs: bridging the gap in Alzheimer's pathogenesis and therapeutics

Alzheimer's disease (AD) is a neurodegenerative disease that primarily affects the elderly population and is the leading cause of dementia. Meanwhile, the vascular hypothesis suggests that vascular damage occurs in the early stages of the disease, leading to neurodegeneration and hindered waste clearance, which in turn triggers a series of events including the accumulation of amyloid plaques and Tau protein tangles. Non-coding RNAs (ncRNAs), including long noncoding RNAs (lncRNAs), microRNAs (miRNAs), and circular RNAs (circRNAs), have been found to be involved in the regulation of AD. Furthermore, lncRNAs and circRNAs can act as competitive endogenous RNAs to inhibit miRNAs, and their interactions can form a complex regulatory network. Exosomes, which are extracellular vesicles (EVs), are believed to be able to transfer ncRNAs between cells, thus playing a regulatory role in the brain by crossing the blood-brain barrier (BBB). Exosomes are part of the intercellular carrier system; therefore, utilizing exosomes to deliver drugs to recipient cells might not activate the immune system, making it a potential strategy to treat central nervous system diseases. In this review, we review that AD is a multifactorial neurological disease and that ncRNAs can regulate its multiple pathogenic mechanisms to improve our understanding of the etiology of AD and to simultaneously regulate multiple pathogenic mechanisms of AD through the binding of ncRNAs to exosomes to improve the treatment of AD.

A review of chitosan polysaccharides: Neuropharmacological implications and tissue regeneration

One of the current challenges in targeting neurological disorders is that many therapeutic molecules cannot cross the blood-brain barrier (BBB), which limits the use of natural molecules in nervous tissue regeneration. Thus, the development of new drugs to effectively treat neurological disorders would be a challenge. Natural resources are well known as a source of several therapeutic agents for the treatment of neurologic disorders. Recently, chitosan (CTS) and its derivatives from arthropod exoskeletons, have attracted much attention as a drug delivery system to transport therapeutic substances across the BBB and thanks to other neuroprotective effects including the participation to the CNS regenerations scaffolds to replicate the extracellular matrix and microenvironment of the body. This review will discuss the place of natural resource therapy in targeting neurological disorders. In particular, it will highlight recent understanding and progress in the applications of CTS as drug delivery systems and their therapeutic effects on these disorders through tissue regeneration, as well as the molecular mechanisms by which they exert these effects.

Chitosan Nanoparticle-Mediated Delivery of Curcumin Suppresses Tumor Growth in Breast Cancer

Curcumin is a nutraceutical known to have numerous medicinal effects including anticancer activity. However, due to its poor water solubility and bioavailability, the therapeutic impact of curcumin against cancer, including breast cancer, has been constrained. Encapsulating curcumin into chitosan nanoparticles (CHNPs) is an effective method to increase its bioavailability as well as antitumorigenic activity. In the current study, the effects of curcumin-encapsulated CHNPs (Cur-CHNPs) on cell migration, targeted homing and tumor growth were examined using in vitro and in vivo breast cancer models. Cur-CHNPs possessed a monodispersed nature with long-term colloidal stability, and demonstrated significant inhibition of cell viability in vitro, which was potentiated by 5-Fluorouracil (5-FU). Outcomes of the in vivo imaging studies confirmed effective tumor targeting and retention ability of Cur-CHNPs, thereby suppressing breast tumor growth in mice models. Overall, the results demonstrated that Cur-CHNPs could be an effective candidate drug formulation for management of breast cancer.

Polymeric nanoparticles: A promising strategy for treatment of Alzheimer's disease

Alzheimer's disease (AD), is characterised by two major hallmarks: the formation of extracellular β-amyloid (Aβ) plaques and the hyperphosphorylation of tau protein, thus leading to the formation of neurofibrillary tangles. These hallmarks cause synaptic loss, neuronal damage, and the development of neuroinflammation and oxidative stress, which promote AD progression. Thus, the goal of treating AD is eliminating these hallmarks, to prevent AD progression and decrease symptoms. However, current available therapies provide symptomatic relief rather than treating the underlying cause of the disease, because the restrictive nature of the blood brain barrier (BBB) impedes the entry of drugs, thereby affecting drug efficacy and bioavailability. Researchers are focusing on developing new therapeutic approaches to bypass the BBB, for achieving site-specific drug delivery with the highest possible bioavailability and the lowest adverse effects. Recently explored therapeutic strategies include use of biologic agents such as monoclonal antibodies. Aducanumab, a strong candidate for treating AD, has been granted accelerated Food and Drug Administration approval; however, safety concerns may hinder its future use. Thus, nanotechnological approaches have led to a new era of AD treatment. Nanoparticles (NPs), because of their small particle size, can cross the BBB, thus enhancing drug pharmacokinetic properties and enabling targeted drug delivery. Polymeric NPs have been extensively studied, because of their simple production, biodegradability, biocompatibility, and unique architecture. These NPs provide a flexible vesicle that can be easily tailored to achieve desired physicochemical features. In this review, various types of polymer-based-NPs are discussed, highlighting the properties of fabricated NPs, which have multiple benefits in AD treatment, including anti-amyloid, antioxidant, and anti-inflammatory effects.

Succinimide Derivatives as Acetylcholinesterase Inhibitors-In Silico and In Vitro Studies

We studied the effect of succinimide derivatives on acetylcholinesterase activity due to the interest in compounds that influence this enzyme's activity, which could help treat memory issues more effectively. The following parameters were established for this purpose based on kinetic investigations of the enzyme in the presence of succinimide derivatives: the half-maximal inhibitory concentration, the maximum rate, the inhibition constant, and the Michaelis-Menten constant. Furthermore, computational analyses were performed to determine the energy required for succinimide derivatives to dock with the enzyme's active site. The outcomes acquired in this manner demonstrated that all compounds inhibited acetylcholinesterase in a competitive manner. The values of the docking energy parameters corroborated the kinetic parameter values, which indicated discernible, albeit slight, variations in the inhibitory intensity among the various derivatives.

Multifunctional Nanocarriers for Alzheimer's Disease: Befriending the Barriers

Neurodegenerative diseases (NDDs) have been increasing in incidence in recent years and are now widespread worldwide. Neuronal death is defined as the progressive loss of neuronal structure or function which is closely associated with NDDs and represents the intrinsic features of such disorders. Amyotrophic lateral sclerosis, frontotemporal dementia, Alzheimer's, Parkinson's, and Huntington's diseases (AD, PD, and HD, respectively) are considered neurodegenerative diseases that affect a large number of people worldwide. Despite the testing of various drugs, there is currently no available therapy that can remedy or effectively slow the progression of these diseases. Nanomedicine has the potential to revolutionize drug delivery for the management of NDDs. The use of nanoparticles (NPs) has recently been developed to improve drug delivery efficiency and is currently subjected to extensive studies. Nanoengineered particles, known as nanodrugs, can cross the blood-brain barrier while also being less invasive compared to the most treatment strategies in use. Polymeric, magnetic, carbonic, and inorganic NPs are examples of NPs that have been developed to improve drug delivery efficiency. Primary research studies using NPs to cure AD are promising, but thorough research is needed to introduce these approaches to clinical use. In the present review, we discussed the role of metal-based NPs, polymeric nanogels, nanocarrier systems such as liposomes, solid lipid NPs, polymeric NPs, exosomes, quantum dots, dendrimers, polymersomes, carbon nanotubes, and nanofibers and surfactant-based systems for the therapy of neurodegenerative diseases. In addition, we highlighted nanoformulations such as N-butyl cyanoacrylate, poly(butyl cyanoacrylate), D-penicillamine, citrate-coated peptide, magnetic iron oxide, chitosan (CS), lipoprotein, ceria, silica, metallic nanoparticles, cholinesterase inhibitors, an acetylcholinesterase inhibitors, metal chelators, anti-amyloid, protein, and peptide-loaded NPs for the treatment of AD.

Nanotechnology-based Drug Delivery for Alzheimer's and Parkinson's Diseases

The delivery of drugs to the brain is quite challenging in the treatment of the central nervous system (CNS) diseases due to the blood-brain barrier and the blood-cerebrospinal fluid barrier. However, significant developments in nanomaterials employed by nanoparticle drug-delivery systems have substantial potential to cross or bypass these barriers leading to enhanced therapeutic efficacies. Advances in nanoplatform, nanosystems based on lipids, polymers and inorganic materials have been extensively studied and applied in treating Alzheimer's and Parkinson's diseases. In this review, various types of brain drug delivery nanocarriers are classified, summarized, and their potential as drug delivery systems in Alzheimer's and Parkinson's diseases is discussed. Finally, challenges facing the clinical translation of nanoparticles from bench to bedside are highlighted.

Intranasal Drug Delivery by Nanotechnology: Advances in and Challenges for Alzheimer's Disease Management

Alzheimer's disease, a progressive neurodegenerative condition, is characterized by a gradual decline in cognitive functions. Current treatment approaches primarily involve the administration of medications through oral, parenteral, and transdermal routes, aiming to improve cognitive function and alleviate symptoms. However, these treatments face limitations, such as low bioavailability and inadequate permeation. Alternative invasive methods, while explored, often entail discomfort and require specialized assistance. Therefore, the development of a non-invasive and efficient delivery system is crucial. Intranasal delivery has emerged as a potential solution, although it is constrained by the unique conditions of the nasal cavity. An innovative approach involves the use of nano-carriers based on nanotechnology for intranasal delivery. This strategy has the potential to overcome current limitations by providing enhanced bioavailability, improved permeation, effective traversal of the blood-brain barrier, extended retention within the body, and precise targeting of the brain. The comprehensive review focuses on the advancements in designing various types of nano-carriers, including polymeric nanoparticles, metal nanoparticles, lipid nanoparticles, liposomes, nanoemulsions, Quantum dots, and dendrimers. These nano-carriers are specifically tailored for the intranasal delivery of therapeutic agents aimed at combatting Alzheimer's disease. In summary, the development and utilization of intranasal delivery systems based on nanotechnology show significant potential in surmounting the constraints of current Alzheimer's disease treatment strategies. Nevertheless, it is essential to acknowledge regulatory as well as toxicity concerns associated with this route; meticulous consideration is required when engineering a carrier. This comprehensive review underscores the potential to revolutionize Alzheimer's disease management and highlights the importance of addressing regulatory considerations for safe and effective implementations. Embracing this strategy could lead to substantial advancements in the field of Alzheimer's disease treatment.

Single and Multitarget Systems for Drug Delivery and Detection: Up-to-Date Strategies for Brain Disorders

This review summarizes the recent findings on the development of different types of single and multitarget nanoparticles for disease detection and drug delivery to the brain, focusing on promising active principles encapsulated and nanoparticle surface modification and functionalization. Functionalized nanoparticles have emerged as promising tools for the diagnosis and treatment of brain disorders, offering a novel approach to addressing complex neurological challenges. They can act as drug delivery vehicles, transporting one or multiple therapeutic agents across the blood-brain barrier and precisely releasing them at the site of action. In diagnostics, functionalized nanoparticles can serve as highly sensitive contrast agents for imaging techniques such as magnetic resonance imaging and computed tomography scans. By attaching targeting ligands to the nanoparticles, they can selectively accumulate in the affected areas of the brain, enhancing the accuracy of disease detection. This enables early diagnosis and monitoring of conditions like Alzheimer's or Parkinson's diseases. While the field is still evolving, functionalized nanoparticles represent a promising path for advancing our ability to diagnose and treat brain disorders with greater precision, reduced invasiveness, and improved therapeutic outcomes.

Managing Temporomandibular Joint Osteoarthritis by Dental Stem Cell Secretome

The potential therapeutic role of the Dental Pulp Stem Cells Secretome (SECR) in a rat model of experimentally induced Temporomandibular Joint (TMJ) Osteoarthritis (OA) was evaluated. Proteomic profiling of the human SECR under specific oxygen tension (5% O2) and stimulation with Tumor Necrosis Factor-alpha (TNF-α) was performed. SECR and respective cell lysates (CL) samples were collected and subjected to SDS-PAGE, followed by LC-MS/MS analysis. The identified proteins were analyzed with Bioinformatic tools. The anti-inflammatory properties of SECR were assessed via an in vitro murine macrophages model, and were further validated in vivo, in a rat model of chemically-induced TMJ-OA by weekly recording of the head withdrawal threshold, the food intake, and the weight change, and radiographically and histologically at 4- and 8-weeks post-treatment. SECR analysis revealed the presence of 50 proteins that were enriched and/or statistically significantly upregulated compared to CL, while many of those proteins were involved in pathways related to "extracellular matrix organization" and "immune system". SECR application in vitro led to a significant downregulation on the expression of pro-inflammatory genes (MMP-13, MMP-9, MMP-3 and MCP-1), while maintaining an increased expression of IL-10 and IL-6. SECR application in vivo had a significant positive effect on all the clinical parameters, resulting in improved food intake, weight, and pain suppression. Radiographically, SECR application had a significant positive effect on trabecular bone thickness and bone density compared to the saline-treated group. Histological analysis indicated that SECR administration reduced inflammation, enhanced ECM and subchondral bone repair and regeneration, thus alleviating TMJ degeneration.

Nanotechnology-empowered therapeutics targeting neurodegenerative diseases

Neurodegenerative diseases are posing pressing health issues due to the high prevalence among aging populations in the 21st century. They are evidenced by the progressive loss of neuronal function, often associated with neuronal necrosis and many related devastating complications. Nevertheless, effective therapeutical strategies to treat neurodegenerative diseases remain a tremendous challenge due to the multisystemic nature and limited drug delivery to the central nervous system. As a result, there is a pressing need to develop effective alternative therapeutics to manage the progression of neurodegenerative diseases. By utilizing the functional reconstructive materials and technologies with specific targeting ability at the nanoscale level, nanotechnology-empowered medicines can transform the therapeutic paradigms of neurodegenerative diseases with minimal systemic side effects. This review outlines the current applications and progresses of the nanotechnology-enabled drug delivery systems to enhance the therapeutic efficacy in treating neurodegenerative diseases. This article is categorized under: Therapeutic Approaches and Drug Discovery > Nanomedicine for Neurological Disease Therapeutic Approaches and Drug Discovery > Emerging Technologies.

Neuroprotection of Multitargeted Phytochemicals against Alzheimer: A Desperate Need from Nature

Background:

Alzheimer’s disease (AD) is an incurable neurodegenerative disorder associated with dementia which leads to the alteration in the psychological and physiological functioning of the individual. From antiquity, medicinal plants serve as important sources of bioactive phytochemicals representing tremendous therapeutic potential. The unavoidable adverse effects associated with synthetic compounds trigger the exploration of new and safer substitutes for the treatment and management of disease conditions. Herbal medication proves to be an emerging and most promising alternative, which is expected to be a revolutionary approach in modern medicine for disease treatment.

Objective:

Several phytochemicals like resveratrol, curcumin, apigenin, docosahexaenoic acid, epigallocatechin gallate, and α-lipoic acid exhibit great potential in the prevention and management of AD. Their use might be a possible remedy and lead to a safe strategy to delay the onset of AD and slow the progression of this pervasive disorder. To determine the potential of these natural components as anti- AD, this review focuses on the updates on clinical studies and research.

Methods:

Extensive literature survey was carried out on natural multitargeted bioactive phytochemicals from various scientific databases like PubMed, Science Direct, Scopus, Clinicaltrails.gov, and many reputed foundations. Current prose emphasizes the identified bioactive compounds as anti-AD, which were reviewed with particular emphasis on their scientific impact and novelty.

Results:

These compounds diminish the pathophysiological aspects of AD; still, further studies are required to prove the safety and efficacy of these compounds in humans.

Conclusion:

This present review might help the researchers, academicians and industrialists in drug development as a new paradigm of drug discovery.

Recent Advancements in Nanomaterials: A Promising Way to Manage Neurodegenerative Disorders

Neurodegenerative diseases (NDs) such as dementia, Alzheimer's disease, Parkinson's disease, frontotemporal dementia, and amyotrophic lateral sclerosis are some of the most prevalent disorders currently afflicting healthcare systems. Many of these diseases share similar pathological hallmarks, including elevated oxidative stress, mitochondrial dysfunction, protein misfolding, excitotoxicity, and neuroinflammation, all of which contribute to the deterioration of the nervous system's structure and function. The development of diagnostic and therapeutic materials in the monitoring and treatment of these diseases remains challenging. One of the biggest challenges facing therapeutic and diagnostic materials is the blood-brain barrier (BBB). The BBB is a multifunctional membrane possessing a plethora of biochemical, cellular, and immunological features that ensure brain homeostasis by preventing the entry and accumulation of unwanted compounds. With regards to neurodegenerative diseases, the recent application of tailored nanomaterials (nanocarriers and nanoparticles) has led to advances in diagnostics and therapeutics. In this review, we provide an overview of commonly used nanoparticles and their applications in NDs, which may offer new therapeutic strategies for the prevention and treatment of neurodegenerative diseases.

Chitosan-Based Nanoparticles for Targeted Nasal Galantamine Delivery as a Promising Tool in Alzheimer’s Disease Therapy

Natural alkaloid galantamine is widely used for the treatment of mild to moderate Alzheimer’s dementia. Galantamine hydrobromide (GH) is available as fast-release tablets, extended-release capsules, and oral solutions. However, its oral delivery can cause some unwanted side effects, such as gastrointestinal disturbances, nausea, and vomiting. Intranasal administration is one possible way to avoid such unwanted effects. In this work, chitosan-based nanoparticles (NPs) were studied as potential GH delivery vehicles for nasal application. The NPs were synthesized via ionic gelation and studied using dynamic light scattering (DLS) as well as by spectroscopic and thermal methods. The GH-loaded chitosan–alginate complex particles were also prepared as a way to modify the release of GH. The high loading efficiency of the GH was confirmed for both types of particles, at 67% for the GH-loaded chitosan NPs and 70% for the complex chitosan/alginate GH-loaded particles. The mean particle size of the GH-loaded chitosan NPs was about 240 nm, while the sodium alginate coated chitosan particles loaded with GH were expectedly bigger, with a mean particle size of ~286 nm. GH release profiles in PBS at 37 °C were obtained for both types of NPs, and it was found that the GH-loaded chitosan NPs allowed the prolonged release of the incorporated drug for a period of 8 h, while the complex GH-loaded chitosan/alginate NPs released the incorporated GH faster. The stability of the prepared GH-loaded NPs was also demonstrated after 1 year of storage at 5 °C ± 3 °C.

Drug delivery to the brain via the nasal route of administration: exploration of key targets and major consideration factors

Background

Cranial nerve-related diseases such as brain tumors, Alzheimer's disease, and epilepsy are serious diseases that continue to threaten human. Brain-related diseases are increasing worldwide, including in the United States and Korea, and these increases are closely related to the exposure to harmful substances and excessive stress caused by rapid industrialization and environmental pollution. Drug delivery to the brain is very important for the effective prevention and treatment of brain-related diseases. However, due to the presence of the blood-brain barrier and the extensive first-pass metabolism effect, the general routes of administration such as oral and intravenous routes have limitations in drug delivery to the brain. Therefore, as an alternative, the nasal-brain drug delivery route is attracting attention as a route for effective drug delivery to the brain.

Areas covered

This review includes physiological factors, advantages, limitations, current application status, especially in clinical applications, and the necessary factors for consideration in formulation development related to nasal-brain drug delivery.

Expert opinion

The nasal-brain drug delivery route has the advantage of enhancing drug delivery to the brain locally, mainly through the olfactory route rather than the systemic circulation. The nasal-brain lymphatic system has recently attracted attention, and it has been implied that the delivery of anticancer drugs to the brain nervous system is possible effectively. However, there are limitations such as low drug permeability, as well as nasal mucosa and the mucociliary system, as obstacles in nasal-brain drug delivery. Therefore, to overcome the limitations of nasal-brain drug delivery, the use of nanocarriers and mucoadhesive agents is being attempted. However, very few drugs have been officially approved for clinical application via the nasal-brain drug delivery route. This is probably because the understanding of and related studies on nasal-brain drug delivery are limited. In this review, we tried to explore the major considerations and target factors in drug delivery through the nasal-brain route based on physiological knowledge and formulation research information. This will help to provide a mechanistic understanding of drug delivery through the nasal-brain route and bring us one step closer to developing effective formulations and drugs in consideration of the key factors for nasal-brain drug delivery.

L-Cysteine Modified Chitosan Nanoparticles and Carbon-Based Nanostructures for the Intranasal Delivery of Galantamine

The present study evaluates the use of thiolized chitosan conjugates (CS) in combination with two fundamental carbon nanoforms (carbon dots (CDs) and Hierarchical Porous Carbons (HPC)) for the preparation of intranasally (IN) administrated galantamine (GAL) nanoparticles (NPs). Initially, the modification of CS with L-cysteine (Cys) was performed, and the successful formation of a Cys-CS conjugates was verified via ¹H-NMR, FTIR, and pXRD. The new Cys-CS conjugate showed a significant solubility enhancement in neutral and alkaline pH, improving CS’s utility as a matrix-carrier for IN drug administration. In a further step, drug-loaded NPs were prepared via solid-oil–water double emulsification, and thoroughly analyzed by SEM, DLS, FTIR and pXRD. The results showed the formation of spherical NPs with a smooth surface, while the drug was amorphously dispersed within most of the prepared NPs, with the exemption of those systems contianing the CDs. Finally, in vitro dissolution release studies revealed that the prepared NPs could prolong GAL’s release for up to 12 days. In sum, regarding the most promising system, the results of the present study clearly suggest that the preparation of NPs using both Cys-CS and CDs results in a more thermodynamically stable drug dispersion, while a zero-order release profile was achieved, which is essential to attain a stable in vivo pharmacokinetic behavior.

Biopolymer Nanoparticles for Nose-to-Brain Drug Delivery: A New Promising Approach for the Treatment of Neurological Diseases

Diseases affecting the central nervous system (CNS) are among the most disabling and the most difficult to cure due to the presence of the blood-brain barrier (BBB) which represents an impediment from a therapeutic and diagnostic point of view as it limits the entry of most drugs. The use of biocompatible polymer nanoparticles (NPs) as vehicles for targeted drug delivery to the brain arouses increasing interest. However, the route of administration of these vectors remains critical as the drug must be delivered without being degraded to achieve a therapeutic effect. An innovative approach for the administration of drugs to the brain using polymeric carriers is represented by the nose-to-brain (NtB) route which involves the administration of the therapeutic molecule through the neuro-olfactory epithelium of the nasal mucosa. Nasal administration is a non-invasive approach that allows the rapid transport of the drug directly to the brain and minimizes its systemic exposure. To date, many studies involve the use of polymer NPs for the NtB transport of drugs to the brain for the treatment of a whole series of disabling neurological diseases for which, as of today, there is no cure. In this review, various types of biodegradable polymer NPs for drug delivery to the brain through the NtB route are discussed and particular attention is devoted to the treatment of neurological diseases such as Glioblastoma and neurodegenerative diseases.

Intranasal Delivery of Functionalized Polymeric Nanomaterials to the Brain

Intravenous delivery of nanomaterials containing therapeutic agents and various cargos for treating neurological disorders is often constrained by low delivery efficacy due to difficulties in passing the blood-brain barrier (BBB). Nanoparticles (NPs) administered intranasally can move along olfactory and trigeminal nerves so that they do not need to pass through the BBB, allowing non-invasive, direct access to selective neural pathways within the brain. Hence, intranasal (IN) administration of NPs can effectively deliver drugs and genes into targeted regions of the brain, holding potential for efficacious disease treatment in the central nervous system (CNS). In this review, current methods for delivering conjugated NPs to the brain are primarily discussed. Distinctive potential mechanisms of therapeutic nanocomposites delivered via IN pathways to the brain are then discussed. Recent progress in developing functional NPs for applications in multimodal bioimaging, drug delivery, diagnostics, and therapeutics is also reviewed. This review is then concluded by discussing existing challenges, new directions, and future perspectives in IN delivery of nanomaterials.

Therapeutic Approach to Alzheimer’s Disease: Current Treatments and New Perspectives

Alzheimer’s disease (AD) is the most common cause of dementia. The pathophysiology of this disease is characterized by the accumulation of amyloid-β, leading to the formation of senile plaques, and by the intracellular presence of neurofibrillary tangles based on hyperphosphorylated tau protein. In the therapeutic approach to AD, we can identify three important fronts: the approved drugs currently available for the treatment of the disease, which include aducanumab, donepezil, galantamine, rivastigmine, memantine, and a combination of memantine and donepezil; therapies under investigation that work mainly on Aβ pathology and tau pathology, and which include γ-secretase inhibitors, β-secretase inhibitors, α-secretase modulators, aggregation inhibitors, metal interfering drugs, drugs that enhance Aβ clearance, inhibitors of tau protein hyperphosphorylation, tau protein aggregation inhibitors, and drugs that promote the clearance of tau, and finally, other alternative therapies designed to improve lifestyle, thus contributing to the prevention of the disease. Therefore, the aim of this review was to analyze and describe current treatments and possible future alternatives in the therapeutic approach to AD.

Role of Nanotechnology and Their Perspectives in the Treatment of Kidney Diseases

Nanoparticles (NPs) are differing in particle size, charge, shape, and compatibility of targeting ligands, which are linked to improved pharmacologic characteristics, targetability, and bioavailability. Researchers are now tasked with developing a solution for enhanced renal treatment that is free of side effects and delivers the medicine to the active spot. A growing number of nano-based medication delivery devices are being used to treat renal disorders. Kidney disease management and treatment are currently causing a substantial global burden. Renal problems are multistep processes involving the accumulation of a wide range of molecular and genetic alterations that have been related to a variety of kidney diseases. Renal filtration is a key channel for drug elimination in the kidney, as well as a burgeoning topic of nanomedicine. Although the use of nanotechnology in the treatment of renal illnesses is still in its early phases, it offers a lot of potentials. In this review, we summarized the properties of the kidney and characteristics of drug delivery systems, which affect a drug’s ability should focus on the kidney and highlight the possibilities, problems, and opportunities.

Nose-to-brain drug delivery for the treatment of Alzheimer's Disease: Current advancements and challenges

INTRODUCTION

The irreversible destruction of neurons, progressive loss of memory and cognitive behavior, high cost of therapy, and impact on society desire a better, effective, and affordable treatment of AD. The nose-to-brain drug delivery approach holds a great potential to access the brain without any hindrance of BBB and result in higher bioavailability thus better therapeutic efficacy of anti-AD drugs.

AREAS COVERED

The present review article highlighted the current facts and worldwide statistics of AD and its detailed etiology. Followed by barriers to brain delivery, nose-to-brain delivery, their limitations, and amalgamation with various novel carrier systems. We have emphasized recent advancements in nose-to-brain delivery using mucoadhesive, stimuli-responsive carriers, polymeric nanoparticles, lipid nanoparticles, protein/peptide delivery for treatment of AD.

EXPERT OPINION

The available therapies are symptomatic, mitigate the symptoms of AD at the initial stages. In this lieu, nose-to-brain delivery has the ability to overcome these limitations and increase drug bioavailability in the brain. Various novel strategies including stimuli-responsive systems, nanoparticles, etc. enhance the nasal drug permeation, protects the drug, and enhance its therapeutic potency. Although, successful preclinical data does not assure the clinical success of the therapy and hence exhaustive clinical investigations are needed to make the therapy available for patients.

Drug Delivery Systems and Strategies to Overcome the Barriers of Brain

The transport of drugs to the central nervous system is the most challenging task for conventional drug delivery systems. Reduced permeability of drugs through the blood-brain barrier is a major hurdle in delivering drugs to the brain. Hence, various strategies for improving drug delivery through the blood-brain barrier are currently being explored. Novel drug delivery systems (NDDS) offer several advantages, including high chemical and biological stability, suitability for both hydrophobic and hydrophilic drugs, and can be administered through different routes. Furthermore, the conjugation of suitable ligands with these carriers tend to potentiate targeting to the endothelium of the brain and could facilitate the internalization of drugs through endocytosis. Further, the intranasal route has also shown potential, as a promising alternate route, for the delivery of drugs to the brain. This can deliver the drugs directly to the brain through the olfactory pathway. In recent years, several advancements have been made to target and overcome the barriers of the brain. This article deals with a detailed overview of the diverse strategies and delivery systems to overcome the barriers of the brain for effective delivery of drugs.

Nanotechnology-based drug delivery for central nervous system disorders

Drug delivery to central nervous system (CNS) diseases is very challenging since the presence of the innate blood-brain barrier (BBB) and the blood-cerebrospinal fluid barrier that impede drug delivery. Among new strategies to overcome these limitations and successfully deliver drugs to the CNS, nanotechnology-based drug delivery platform, offers potential therapeutic approach for the treatment of some common neurological disorders like Alzheimer's disease, frontotemporal dementia, amyotrophic lateral sclerosis, Parkinson's disease, Huntington's disease. This review aimed to highlight advances in research on the development of nano-based therapeutics for their implications in therapy of CNS disorders. The challenges during clinical translation of nanomedicine from bench to bed side is also discussed.

Intranasal galantamine/chitosan complex nanoparticles elicit neuroprotection potentials in rat brains via antioxidant effect

BACKGROUND

Alzheimer's disease is a common cause of dementia in the elderly. Galantamine hydrobromide (GH) is an anti-Alzheimer cholinesterase inhibitor that has an intrinsic antioxidant effect. In a previous study, GH was complexed with chitosan to prepare intranasal GH/chitosan complex nanoparticles (CX-NP2). The nanoparticles were located in rat brains 1 h after nasal administration and showed pharmacological superiority to GH nasal solution without showing histopathological toxicity.

OBJECTIVE

This study aimed to investigate whether the long-term administration of CX-NP2 leads to biochemical toxicity in rat brains compared to GH nasal solution.

METHODS

CX-NP2 dispersion and GH solution were administrated intranasally to male Wistar rats for 30 days (3 mg/kg/day). Malondialdehyde (MDA), lipid peroxidation marker, glutathione (GSH), superoxide dismutase (SOD) activity and tumor necrosis factor-α (TNF-α) were assessed in the brain extracts in all groups.

RESULTS

There was statistically insignificant difference between the CX-NP2 and GH nasal solution treated groups in all biochemical toxicity parameters assessed. Interestingly, MDA and TNF-α levels in the CX-NP2-treated group significantly decreased compared to the control group. Also, GSH level and SOD activity were significantly enhanced in CX-NP2 treated group compared to the control group.

CONCLUSIONS

CX-NP2 did not induce a statistically significant oxidative stress or neuroinflammation in rat brains after 30-day treatment, they rather elicited neuroprotective potentials.HighlightsIntranasal GH/chitosan complex nanoparticles (CX-NP2) show promising potential as a brain targeting carrier.Compared to GH nasal solution, nasal CX-NP2 formulation did not exert oxidative stress nor neuroinflammation when administered for 30 days.

Natural biomaterials in brain repair: A focus on collagen

Biomaterials derived from natural resources have increasingly been used for versatile applications in the central nervous system (CNS). Thanks to their biocompatibility and biodegradability, natural biomaterials offer vast possibilities for future clinical repair strategies for the CNS. These materials can be used for diverse applications such as hydrogels to fill the tissue cavities, microparticles to deliver drugs across the blood-brain barrier, and scaffolds to transplant stem cells. In this review, various uses of prominent protein and polysaccharide biomaterials, with a special focus on collagen, in repair and regenerative applications for the brain are summarized together with their individual advantages and disadvantages.

Galantamine nanoparticles outperform oral galantamine in an Alzheimer's rat model: pharmacokinetics and pharmacodynamics

Aim: Galantamine is an acetylcholinesterase inhibitor frequently used in Alzheimer's disease management. Its cholinergic adverse effects and rapid elimination limit its therapeutic outcomes. We investigated the pharmacodynamics and pharmacokinetics of 2-week intranasal galantamine-bound chitosan nanoparticles (G-NP) treatment in scopolamine-induced Alzheimer's disease rat model. Materials & methods: Behavioral, neurobiochemical and histopathological changes were assessed and compared with oral and nasal solutions. Brain uptake and pharmacokinetics were determined using a novel validated LC/MS assay. Results: G-NP enhanced spatial memory, exploring behavior and cholinergic transmission in rats. Beta-amyloid deposition and Notch signaling were suppressed and the histopathological degeneration was restored. G-NP potentiated galantamine brain delivery and delayed its elimination. Conclusion: G-NP hold promising therapeutic potentials and brain targeting, outperforming conventional galantamine therapy.

Intranasal drug delivery for treatment of Alzheimer's disease

The Alzheimer's disease is a neurodegenerative condition with severe consequences interfering with patient quality of life. It is characterized as a progressive and irreversible brain disorder hampering memory and thinking, affecting the capacity to perform daily tasks leading to physical and cognitive incapacitation. The conventional treatment occurs by the oral route, but it presents relevant drawbacks such as low bioavailability, fast metabolism, limited brain exposure, and undesirable side effects. The intranasal route has been proposed as a promising alternative to deliver drugs and improve the Alzheimer's disease treatment. Still, there is not a clear alternative delivery system available in the market with advantageous bioavailability and safety. The aim of this review is to perform an overview on the strategies for drug intranasal delivery for Alzheimer's disease treatment. The advantages and disadvantages of this delivery route and the delivery systems developed so far are discussed. A special focus is given on the use of permeation enhancers, the types of intranasal drug delivery devices, as well as possible toxicity concerns.

The application of multifunctional nanomaterials in Alzheimer's disease: A potential theranostics strategy

By virtue of their small size, nanomaterials can cross the blood-brain barrier and, when modified to target specific cells or regions, can achieve high bioavailability at the intended site of action. Modified nanomaterials are therefore promising agents for the diagnosis and treatment of neurodegenerative diseases such as Alzheimer's disease (AD). Here we review the roles and mechanisms of action of nanomaterials in AD. First, we discuss the general characteristics of nanomaterials and their application to nanomedicine. Then, we summarize recent studies on the diagnosis and treatment of AD using modified nanomaterials. These studies indicate that using nanomaterials is a potential strategy for AD treatment by slowing the progression of AD through enhanced therapeutic effects.

Microemulsion-Based Media in Nose-to-Brain Drug Delivery

Nose-to-brain drug delivery has recently attracted enormous attention as an alternative to other delivery routes, including the most popular oral one. Due to the unique anatomical features of the nasal cavity, drugs administered intranasally can be delivered directly to the central nervous system. The most important advantage of this approach is the ability to avoid the blood-brain barrier surrounding the brain and blocking the entry of exogenous substances to the central nervous system. Moreover, selective brain targeting could possibly avoid peripheral side effects of pharmacotherapy. The challenges associated with nose-to-brain drug delivery are mostly due to the small volume of the nasal cavity and insufficient drug absorption from nasal mucosa. These issues could be minimized by using a properly designed drug carrier. Microemulsions as potential drug delivery systems offer good solubilizing properties and the ability to enhance drug permeation through biological membranes. The aim of this review is to summarize the current status of the research focused on microemulsion-based systems for nose-to-brain delivery with special attention to the most extensively investigated neurological and psychiatric conditions, such as neurodegenerative diseases, epilepsy, and schizophrenia.

Road From Nose to Brain for Treatment of Alzheimer: The Bumps and Humps

Vulnerability of the brain milieu to even the subtle changes in its normal physiology is guarded by a highly efficient blood brain barrier. A number of factors i.e. molecular weight of the drug, its route of administration, lipophilic character, etc. play a significant role in its sojourn through the Blood Brain Barrier (BBB) and limit the movement of drug into brain tissue through BBB. To overcome these problems, alternative routes of drug administration have been explored to target the drugs to brain tissue. Nasal route has been widely reported for the administration of drugs for treatment of Alzheimer. In this innovative approach, the challenge of BBB is bypassed. Through this route, both the larger as well as polar molecules can be made to reach the brain tissues. Generally, these systems are either pH dependent or temperature dependent. The present review highlights the anatomy of nose, mechanisms of drug delivery from nose to brain, critical factors in the formulation of nasal drug delivery system, nasal formulations of various drugs that have been tried for their nasal delivery for treatment of Alzheimer. It also dives deep to understand the factors that contribute to the success of such formulations to carve out a direction for this niche area to be explored further.

Recent Advances in Nanotherapeutic Interventions for the Treatment of Alzheimer's Disease

Alzheimer's disease (AD), with impairment of learning and memory as the common clinical manifestations, is one of the most challenging diseases affecting individuals, their families and society as a whole. The fact that its prevalence is escalating rapidly, with the total number of AD patients estimated to reach 115.4 million by 2050, has made the disease a very challenging ailment worldwide. Several biological barriers like the bloodbrain barrier (BBB), drug efflux by P-glycoprotein and the blood-cerebrospinal fluid barrier restrict the delivery of conventional AD drugs to the central nervous system (CNS), thereby limiting their effectiveness. In order to overcome the above physiological barriers, the development of nanomedicines has been extensively explored. The present review provides an insight into the pathophysiology of AD and risk factors associated with AD. Besides, various nanoformulations reported in the literature for the diagnosis and treatments of AD have been classified and summarised. The patented nanoformulations for AD and details of nanoformulations which are in clinical trials are also mentioned. The review would be helpful to researchers and scientific community by providing them with information related to the recent advances in nanointerventions for the diagnosis and treatment of AD, which they can further explore for better management of the disease. However, although the nanotherapeutics for managing AD have been extensively explored, the factors which hinder their commercialisation, the toxicity concern being one of them, need to be addressed so that effective nanotherapeutics for AD can be developed for clinical use.

Nanotechnology to improve the Alzheimer's disease therapy with natural compounds

Alzheimer's disease (AD) is a form of dementia with high impact worldwide, accounting with more than 46 million cases. It is estimated that the number of patients will be four times higher in 2050. The initial symptoms of AD are almost imperceptible and typically involve lapses of memory in recent events. However, the available medicines still focus on controlling the symptoms and do not cure the disease. Regarding the advances in the discovery of new treatments for this devastating disease, natural compounds are gaining increasing relevance in the treatment of AD. Nevertheless, they present some limiting characteristics such as the low bioavailability and the low ability to cross the blood-brain barrier (BBB) that hinder the development of effective therapies. To overcome these issues, the delivery of natural products by targeting nanocarriers has aroused a great interest, improving the therapeutic activity of these molecules. In this article, a review of the research progress on drug delivery systems (DDS) to improve the therapeutic activity of natural compounds with neuroprotective effects for AD is presented. Graphical abstract.

Nanoparticlized System: Promising Approach for the Management of Alzheimer's Disease through Intranasal Delivery

Alzheimer's disease (AD) is a neurodegenerative brain problem and responsible for causing dementia in aged people. AD has become most common neurological disease in the elderly population worldwide and its treatment remains still challengeable. Therefore, there is a need of an efficient drug delivery system which can deliver the drug to the target site. Nasal drug delivery has been used since prehistoric times for the treatment of neurological disorders like Alzheimer's disease (AD). For delivering drug to the brain, blood brain barrier (BBB) is a major rate limiting factor for the drugs. The desired drug concentration could not be achieved through the conventional drug delivery system. Thus, nanocarrier based drug delivery systems are promising for delivering drug to brain. Nasal route is a most convenient for targeting drug to the brain. Several factors and mechanisms need to be considered for an effective delivery of drug to the brain particularly AD. Various nanoparticlized systems such as nanoparticles, liposomes, exosomes, phytosomes, nanoemulsion, nanosphere, etc. have been recognized as an effective drug delivery system for the management of AD. These nanocarriers have been proven with improved permeability as well as bioavailability of the anti-Alzheimer's drugs. Some novel drug delivery systems of anti-Alzheimer drugs are under investigation of different phase of clinical trials. Present article highlights on the nanotechnology based intranasal drug delivery system for the treatment of Alzheimer's disease. Furthermore, consequences of AD, transportation mechanism, clinical updates and recent patents on nose to brain delivery for AD have been discussed.

Nano Carrier Drug Delivery Systems for the Treatment of Neuropsychiatric Disorders: Advantages and Limitations

Neuropsychiatric diseases are one of the main causes of disability, affecting millions of people. Various drugs are used for its treatment, although no effective therapy has been found yet. The blood brain barrier (BBB) significantly complicates drugs delivery to the target cells in the brain tissues. One of the problem-solving methods is the usage of nanocontainer systems. In this review we summarized the data about nanoparticles drug delivery systems and their application for the treatment of neuropsychiatric disorders. Firstly, we described and characterized types of nanocarriers: inorganic nanoparticles, polymeric and lipid nanocarriers, their advantages and disadvantages. We discussed ways to interact with nerve tissue and methods of BBB penetration. We provided a summary of nanotechnology-based pharmacotherapy of schizophrenia, bipolar disorder, depression, anxiety disorder and Alzheimer's disease, where development of nanocontainer drugs derives the most active. We described various experimental drugs for the treatment of Alzheimer's disease that include vector nanocontainers targeted on β-amyloid or tau-protein. Integrally, nanoparticles can substantially improve the drug delivery as its implication can increase BBB permeability, the pharmacodynamics and bioavailability of applied drugs. Thus, nanotechnology is anticipated to overcome the limitations of existing pharmacotherapy of psychiatric disorders and to effectively combine various treatment modalities in that direction.

Use of Biodegradable, Chitosan-Based Nanoparticles in the Treatment of Alzheimer's Disease

Alzheimer's disease (AD) is a progressive neurodegenerative disorder that affects more than 24 million people worldwide and represents an immense medical, social and economic burden. While a vast array of active pharmaceutical ingredients (API) is available for the prevention and possibly treatment of AD, applicability is limited by the selective nature of the blood-brain barrier (BBB) as well as by their severe peripheral side effects. A promising solution to these problems is the incorporation of anti-Alzheimer drugs in polymeric nanoparticles (NPs). However, while several polymeric NPs are nontoxic and biocompatible, many of them are not biodegradable and thus not appropriate for CNS-targeting. Among polymeric nanocarriers, chitosan-based NPs emerge as biodegradable yet stable vehicles for the delivery of CNS medications. Furthermore, due to their mucoadhesive character and intrinsic bioactivity, chitosan NPs can not only promote brain penetration of drugs via the olfactory route, but also act as anti-Alzheimer therapeutics themselves. Here we review how chitosan-based NPs could be used to address current challenges in the treatment of AD; with a specific focus on the enhancement of blood-brain barrier penetration of anti-Alzheimer drugs and on the reduction of their peripheral side effects.

Boosting the autophagy-lysosomal pathway by phytochemicals: A potential therapeutic strategy against Alzheimer's disease

The lysosome is a membrane-enclosed organelle in eukaryotic cells, which has basic pattern recognition for nutrient-dependent signal transduction. In Alzheimer's disease, the already declining autophagy-lysosomal function is exacerbated by an increased need for clearance of damaged proteins and organelles in aged cells. Recent evidence suggests that numerous diseases are linked to impaired autophagy upstream of lysosomes. In this way, a comprehensive survey on the pathophysiology of the disease seems necessary. Hence, in the first section of this review, we will discuss the ultimate findings in lysosomal signaling functions and how they affect cellular metabolism and trafficking under neurodegenerative conditions, specifically Alzheimer's disease. In the second section, we focus on how natural products and their derivatives are involved in the regulation of inflammation and lysosomal dysfunction pathways, including how these should be considered a crucial target for Alzheimer's disease therapeutics.

Treatment of Alzheimer's diseases using donepezil nanoemulsion: an intranasal approach

Alzheimer disease (AD) is very common among the older people. There are few medications available as oral and suspension dosage forms for the management of AD. Due to the rising cases of AD and the associated risks of the existing line of treatment, oil in water (o/w) nanoemulsion (NE) loaded with donepezil was prepared to explore intranasal route of administration. The NE was prepared using labrasol (10%), cetyl pyridinium chloride (1% in 80% water), and glycerol (10%), with a drug concentration of 1 mg/ml. The developed NE was characterized for particle size, polydispersity index (PDI), and zeta potential. In vitro release studies were conducted to observe the release of drug. Further in vivo studies of developed NE were done on Sprague Dawley rats using technetium pertechnetate (^99mTc) labeled formulations to investigate the nose to brain drug delivery pathway. The nanoemulsion showed particle size of 65.36 nm with a PDI of 0.084 and zeta potential of -10.7 mV. In vitro release studies showed maximum release of 99.22% in 4 h in phosphate-buffered saline, 98% in 2 h in artificial cerebrospinal fluid, and 96% in 2 h in simulated nasal fluid. The cytotoxicity and antioxidant activity of the NE showed dose-dependent cytotoxicity and % radical scavenging activity (%RSA). The images of giemsa staining also confirmed that the developed formulation has no impact on the morphology of cells. Scintigrams showed maximum uptake of NE in the brain. The findings suggested that the developed NE loaded with donepezil hydrochloride could serve as a new approach for the treatment of Alzheimer via nose to brain drug delivery. Graphical abstract.

Hierarchical Porous Carbon-PLLA and PLGA Hybrid Nanoparticles for Intranasal Delivery of Galantamine for Alzheimer's Disease Therapy

In the present study, poly(l-lactic acid) (PLLA) and poly(lactide-co-glycolide) (PLGA) hybrid nanoparticles were developed for intranasal delivery of galantamine, a drug used in severe to moderate cases of Alzheimer’s disease. Galantamine (GAL) was adsorbed first in hierarchical porous carbon (HPC). Formulations were characterized by FT-IR, which showed hydrogen bond formation between GAL and HPC. Furthermore, GAL became amorphous after adsorption, as confirmed by XRD and differential scanning calorimetry (DSC) studies. GAL was quantified to be 21.5% w/w by TGA study. Adsorbed GAL was nanoencapsulated in PLLA and PLGA, and prepared nanoparticles were characterized by several techniques. Their sizes varied between 182 and 394 nm, with an exception that was observed in nanoparticles that were prepared by PLLA and adsorbed GAL that was found to be 1302 nm in size. DSC thermographs showed that GAL was present in its crystalline state in nanoparticles before its adsorption to HPC, while it remained in its amorphous phase after its adsorption in the prepared nanoparticles. It was found that the polymers controlled the release of GAL both when it was encapsulated alone and when it was adsorbed on HPC. Lastly, PLGA hybrid nanoparticles were intranasally-administered in healthy, adult, male Wistar rats. Administration led to successful delivery to the hippocampus, the brain area that is primarily and severely harmed in Alzheimer’s disease, just a few hours after a single dose.

Novel therapeutic strategies for Alzheimer's disease: Implications from cell-based therapy and nanotherapy

Alzheimer's disease (AD) is a multifactorial neurodegenerative disease which leads to progressive dysfunction of cognition, memory and learning in elderly people. Common therapeutic agents are not only inadequate to suppress the progression of AD pathogenesis but also produce deleterious side effects; hence, development of alternative therapies is required to specifically suppress complications of AD. The current review provides a commentary on conventional as well as novel therapeutic approaches with an emphasis on stem cell and nano-based therapies for improvement and management of AD pathogenesis. According to our overview of the current literature, AD is a multi-factorial disorder with various pathogenic trajectories; hence, a multifunctional strategy to create effective neuroprotective agents is required to treat this disorder.